diff --git a/.github/workflows/mirror-to-gitlab.yml b/.github/workflows/mirror-to-gitlab.yml
index e1ee2766..b3636722 100644
--- a/.github/workflows/mirror-to-gitlab.yml
+++ b/.github/workflows/mirror-to-gitlab.yml
@@ -2,9 +2,13 @@ name: Mirror to GitLab
 
 on:
   push:
-    branches: ["**"]
+    branches:
+      - main
+      - dev
   delete:
-    branches: ["**"]
+    branches:
+      - main
+      - dev
 
 jobs:
   mirror:
diff --git a/.gitleaks.toml b/.gitleaks.toml
index f23b4621..b2ea72c3 100644
--- a/.gitleaks.toml
+++ b/.gitleaks.toml
@@ -45,6 +45,7 @@ regexes = [
 paths = [
   '''(^|/)backend-service/QUICKSTART\.md$''',
   '''(^|/)docs/gateway/API_GATEWAY_FULL_POLICY_SETUP\.md$''',
+  '''(^|/)docs/operations/API_GATEWAY_FULL_POLICY_SETUP\.md$''',
   '''(^|/)gateway/kong/kong\.yml$''',
 ]
 
diff --git a/.pr_agent.toml b/.pr_agent.toml
index 71badea5..01404aec 100644
--- a/.pr_agent.toml
+++ b/.pr_agent.toml
@@ -58,7 +58,6 @@ extra_instructions = """
 - Clarify implementation choices
 """
 
-[config]
 # Model configuration (uncomment to customize)
 # model = "gpt-4-turbo-preview"
 # model = "anthropic/claude-3-5-sonnet-20241022"
diff --git a/AGENTS.md b/AGENTS.md
index 1feb5fc0..23ace47c 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -56,3 +56,33 @@ Query before starting: `memory.search_nodes("LexiLingo")` to load prior context.
 - Have two agents edit the same file concurrently.
 - Skip the test-writer for any new public API endpoint.
 - Commit without running `flutter analyze` (Flutter) or `pytest` (backend).
+
+<!-- ASTRYX:START -->
+Astryx v0.1.3 · 90+ components
+CLI: run every command as `npx astryx <cmd>` (shown below as `astryx ...`).
+
+SETUP (once, in your app entry e.g. main.tsx) — without these, components render unstyled:
+  import "@astryxdesign/core/reset.css";
+  import "@astryxdesign/core/astryx.css";
+
+WORKFLOW — discover, don't guess. Before writing UI:
+1. `astryx build "<idea>"` — START HERE: returns a kit (closest [page] + [block]s + [component]s). No args = full playbook.
+2. `astryx template <name> [--skeleton]` — scaffold the [page]/[block]s it named, or study their layout. Templates are reference code.
+3. `astryx component <Name>` — props + examples for every component you use.
+
+RULES:
+- No <div> — components do all layout/spacing. Full page → AppShell; sidebar nav → SideNav.
+- Frame first: pick the shell (AppShell / Layout+LayoutPanel) and budget regions in px BEFORE writing content (`astryx docs layout`).
+- Dense data = rows (Table, List/Item) edge-to-edge — never Card-wrapped list items. Card = dashboard widgets, galleries, settings groups only.
+- Status → StatusDot/Token; Badge only for counts and enumerated states, never decoration.
+- Custom styling: component props first; else style/className with tokens — var(--color-*|--spacing-*|--radius-*). No raw hex/px. (No StyleX/Tailwind compiler here — don't use xstyle/utility classes.)
+- Tokens for every value (`astryx docs tokens`). Brand/accent via `astryx theme` — never override --color-* in :root.
+
+MORE CLI:
+  search "<query>"   find any component / hook / doc / template / block
+  component --list   90+ components by category
+  template --list    page + block recipes
+  docs <topic>       color, elevation, icons, illustrations, layout, migration, motion, principles, shape, spacing, styling, theme, tokens, typography
+  swizzle <Name>     eject component source for deep customization
+  upgrade --apply    run after any @astryxdesign/core bump
+<!-- ASTRYX:END -->
diff --git a/CLAUDE.md b/CLAUDE.md
index cb69ffe1..eff03b41 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -74,3 +74,33 @@ This project has a code-review-graph knowledge graph. Prefer:
 - Flutter: `Theme.of(context)` tokens only — never hardcode colors or sizes
 - Python: type hints on all function signatures
 - Async Python: `async def` + `await` everywhere in service/handler layer
+
+<!-- ASTRYX:START -->
+Astryx v0.1.3 · 90+ components
+CLI: run every command as `npx astryx <cmd>` (shown below as `astryx ...`).
+
+SETUP (once, in your app entry e.g. main.tsx) — without these, components render unstyled:
+  import "@astryxdesign/core/reset.css";
+  import "@astryxdesign/core/astryx.css";
+
+WORKFLOW — discover, don't guess. Before writing UI:
+1. `astryx build "<idea>"` — START HERE: returns a kit (closest [page] + [block]s + [component]s). No args = full playbook.
+2. `astryx template <name> [--skeleton]` — scaffold the [page]/[block]s it named, or study their layout. Templates are reference code.
+3. `astryx component <Name>` — props + examples for every component you use.
+
+RULES:
+- No <div> — components do all layout/spacing. Full page → AppShell; sidebar nav → SideNav.
+- Frame first: pick the shell (AppShell / Layout+LayoutPanel) and budget regions in px BEFORE writing content (`astryx docs layout`).
+- Dense data = rows (Table, List/Item) edge-to-edge — never Card-wrapped list items. Card = dashboard widgets, galleries, settings groups only.
+- Status → StatusDot/Token; Badge only for counts and enumerated states, never decoration.
+- Custom styling: component props first; else style/className with tokens — var(--color-*|--spacing-*|--radius-*). No raw hex/px. (No StyleX/Tailwind compiler here — don't use xstyle/utility classes.)
+- Tokens for every value (`astryx docs tokens`). Brand/accent via `astryx theme` — never override --color-* in :root.
+
+MORE CLI:
+  search "<query>"   find any component / hook / doc / template / block
+  component --list   90+ components by category
+  template --list    page + block recipes
+  docs <topic>       color, elevation, icons, illustrations, layout, migration, motion, principles, shape, spacing, styling, theme, tokens, typography
+  swizzle <Name>     eject component source for deep customization
+  upgrade --apply    run after any @astryxdesign/core bump
+<!-- ASTRYX:END -->
diff --git a/Makefile b/Makefile
index 863ef5d0..a163b45c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 .DEFAULT_GOAL := help
 
-APP_DIR := lexilingo_app
+APP_DIR := flutter-app
 FLUTTER ?= flutter
 DART ?= dart
 
diff --git a/admin-service/package-lock.json b/admin-service/package-lock.json
index 2e8464cf..573d03f8 100644
--- a/admin-service/package-lock.json
+++ b/admin-service/package-lock.json
@@ -10,32 +10,32 @@
       "dependencies": {
         "@gsap/react": "^2.1.2",
         "@hookform/resolvers": "^5.2.2",
-        "@tanstack/react-query": "^5.101.0",
+        "@tanstack/react-query": "^5.101.2",
         "@vercel/analytics": "^2.0.1",
-        "antd": "^6.4.4",
-        "axios": "^1.18.0",
+        "antd": "^6.5.0",
+        "axios": "^1.18.1",
         "dayjs": "^1.11.21",
         "dotenv": "^17.4.2",
         "gsap": "^3.15.0",
-        "lucide-react": "^1.18.0",
+        "lucide-react": "^1.23.0",
         "react": "^19.2.7",
         "react-dom": "^19.2.7",
-        "react-hook-form": "^7.79.0",
-        "react-router-dom": "^7.17.0",
-        "recharts": "^3.8.1",
-        "three": "^0.184.0",
-        "vercel": "^54.14.0",
+        "react-hook-form": "^7.81.0",
+        "react-router-dom": "^7.18.1",
+        "recharts": "^3.9.2",
+        "three": "^0.185.1",
+        "vercel": "^54.20.1",
         "zod": "^4.4.3",
         "zustand": "^5.0.14"
       },
       "devDependencies": {
-        "@types/node": "^25.9.3",
+        "@types/node": "^25.9.4",
         "@types/react": "^19.2.17",
         "@types/react-dom": "^19.2.3",
-        "@types/three": "^0.184.1",
-        "@vitejs/plugin-react": "^6.0.1",
+        "@types/three": "^0.185.0",
+        "@vitejs/plugin-react": "^6.0.3",
         "typescript": "^6.0.3",
-        "vite": "^8.0.16",
+        "vite": "^8.1.3",
         "vitest": "^4.1.8"
       }
     },
@@ -92,13 +92,13 @@
       }
     },
     "node_modules/@ant-design/icons": {
-      "version": "6.2.5",
-      "resolved": "https://registry.npmjs.org/@ant-design/icons/-/icons-6.2.5.tgz",
-      "integrity": "sha512-0hKtoKqTjGFOndUyJLJmC9Cg6k4rEO7rLo6xmgbNJH+/ZX1C57RVals2v1j1knHl9n7Q+sBOveTvn931wLOCKw==",
+      "version": "6.3.2",
+      "resolved": "https://registry.npmjs.org/@ant-design/icons/-/icons-6.3.2.tgz",
+      "integrity": "sha512-B6O5a5XJ4wjtNOfZejXYwHW5zvKV5gYkjGf11dHGLEbKn0ABDGndo41+gfIiXyTFhvESj4XTotuud33mUFid0g==",
       "license": "MIT",
       "dependencies": {
         "@ant-design/colors": "^8.0.1",
-        "@ant-design/icons-svg": "^4.4.2",
+        "@ant-design/icons-svg": "^4.5.0",
         "@rc-component/util": "^1.11.0",
         "clsx": "^2.1.1"
       },
@@ -111,9 +111,9 @@
       }
     },
     "node_modules/@ant-design/icons-svg": {
-      "version": "4.4.2",
-      "resolved": "https://registry.npmjs.org/@ant-design/icons-svg/-/icons-svg-4.4.2.tgz",
-      "integrity": "sha512-vHbT+zJEVzllwP+CM+ul7reTEfBR0vgxFe7+lREAsAA7YGsYpboiq2sQNeQeRvh09GfQgs/GyFEvZpJ9cLXpXA==",
+      "version": "4.5.0",
+      "resolved": "https://registry.npmjs.org/@ant-design/icons-svg/-/icons-svg-4.5.0.tgz",
+      "integrity": "sha512-1BTUFyKPTBZ53MuTP8s0k5SFEXL7o3VHEOwLgzaoWKwnBeqIcqUtVshc4SKzhI6uACfqhJqBwBUE9FsWR3uULA==",
       "license": "MIT"
     },
     "node_modules/@ant-design/react-slick": {
@@ -208,7 +208,6 @@
       "integrity": "sha512-RSvbQmHzdKzNsLYa/wHrbc3KN4sYLKAdPZxqiM2HATqv/SBk2/ENSHpvXGaLOMcsAyz0poEGqkmmKYG3OWiJEQ==",
       "license": "MIT",
       "optional": true,
-      "peer": true,
       "dependencies": {
         "@emnapi/wasi-threads": "1.2.2",
         "tslib": "^2.4.0"
@@ -220,7 +219,6 @@
       "integrity": "sha512-vgj7R3y3Wgx24IQaGPA/R6YFXLHVMOZ0uVEyIQPaWs+rd1AzfEMXlAC22FYwO1XkKR6NPsq7mUandH8oIRdZFw==",
       "license": "MIT",
       "optional": true,
-      "peer": true,
       "dependencies": {
         "tslib": "^2.4.0"
       }
@@ -231,7 +229,6 @@
       "integrity": "sha512-c95qOXkHdydNKhscBTebqEC1CVAZpyqOfVfBzQ1qgzyl3gfeldUjIggDbIZgDKsHLgnsM+igH7TJ/eAasaVuMA==",
       "license": "MIT",
       "optional": true,
-      "peer": true,
       "dependencies": {
         "tslib": "^2.4.0"
       }
@@ -991,13 +988,13 @@
       }
     },
     "node_modules/@napi-rs/wasm-runtime": {
-      "version": "1.1.5",
-      "resolved": "https://registry.npmjs.org/@napi-rs/wasm-runtime/-/wasm-runtime-1.1.5.tgz",
-      "integrity": "sha512-AWPoBRJ9tsnVhor4sjO7rkni+7p+2IAEFj6cx06UgP10jkQHqay/36uRV/bFkgrh18D9vb4cr8Q0Pthskgzy+Q==",
+      "version": "1.1.6",
+      "resolved": "https://registry.npmjs.org/@napi-rs/wasm-runtime/-/wasm-runtime-1.1.6.tgz",
+      "integrity": "sha512-ZLv/JdUfkvOy9eCnnBaGfiO+XimbjebAeO+MRQqD/B+FR1tnRN0tpKSJHRbE8sFfS6aqsXZ67TQjfwfsxULVbg==",
       "license": "MIT",
       "optional": true,
       "dependencies": {
-        "@tybys/wasm-util": "^0.10.2"
+        "@tybys/wasm-util": "^0.10.3"
       },
       "funding": {
         "type": "github",
@@ -1409,12 +1406,12 @@
       }
     },
     "node_modules/@rc-component/cascader": {
-      "version": "1.16.1",
-      "resolved": "https://registry.npmjs.org/@rc-component/cascader/-/cascader-1.16.1.tgz",
-      "integrity": "sha512-wxLopwM+EBed0zNNGdnGE4coYoqcO+XD42fHgn+pDvO+XzhNFbdgSlSNXdKocIYqccvqgWvoxDPNb0OVRdi59A==",
+      "version": "1.17.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/cascader/-/cascader-1.17.0.tgz",
+      "integrity": "sha512-3cVNG0zrQF1PoXq262L3wGCU+/YLEC1mGSVHDl577dQmA0ZKkXFbY6nwyXo+beCcM7buo49t24jkr+QZdL7O8w==",
       "license": "MIT",
       "dependencies": {
-        "@rc-component/select": "~1.7.1",
+        "@rc-component/select": "~1.8.0",
         "@rc-component/tree": "~1.3.2",
         "@rc-component/util": "^1.11.1",
         "clsx": "^2.1.1"
@@ -1483,12 +1480,12 @@
       }
     },
     "node_modules/@rc-component/dialog": {
-      "version": "1.9.0",
-      "resolved": "https://registry.npmjs.org/@rc-component/dialog/-/dialog-1.9.0.tgz",
-      "integrity": "sha512-zbAAogkg4kkKum79sLE6M+vq1jSAW25zdkafrahgcTP9t9S//SD634Znd1A4c8F2Gc12ZKnehGLsVaaOvZzD2A==",
+      "version": "1.10.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/dialog/-/dialog-1.10.0.tgz",
+      "integrity": "sha512-eDukNlz9vNszAGv7i3zKXdxEd3wgVmNxuJijYt8zvTh17QwTu8KK/bdURRd/lU4qaMzhO1HKKmMrwOnkaw0BvQ==",
       "license": "MIT",
       "dependencies": {
-        "@rc-component/motion": "^1.1.3",
+        "@rc-component/motion": "^1.3.3",
         "@rc-component/portal": "^2.1.0",
         "@rc-component/util": "^1.9.0",
         "clsx": "^2.1.1"
@@ -1594,13 +1591,13 @@
       }
     },
     "node_modules/@rc-component/mentions": {
-      "version": "1.9.0",
-      "resolved": "https://registry.npmjs.org/@rc-component/mentions/-/mentions-1.9.0.tgz",
-      "integrity": "sha512-WUwfFKDSOF5S9UPsNsXcLYtzjTxBGsftTXWRbZuxX6BYrsySISTnujfJNgaaQ6qVzaCDJ35QUkZKvsYxip1C5g==",
+      "version": "1.10.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/mentions/-/mentions-1.10.0.tgz",
+      "integrity": "sha512-CI1njYUVY0NjHtLhNoVmXlJyy568Sfep9Wsak6vmGjtT6uazx98djGYlCXz2xkHhEm73g91Y3MTvzUyE5avI7w==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/input": "~1.3.0",
-        "@rc-component/menu": "~1.3.0",
+        "@rc-component/menu": "~1.4.0",
         "@rc-component/trigger": "^3.0.0",
         "@rc-component/util": "^1.3.0",
         "clsx": "^2.1.1"
@@ -1611,9 +1608,9 @@
       }
     },
     "node_modules/@rc-component/menu": {
-      "version": "1.3.1",
-      "resolved": "https://registry.npmjs.org/@rc-component/menu/-/menu-1.3.1.tgz",
-      "integrity": "sha512-pSZl9nBPgKgxN0aaW7NilIBEwWsc+43S+ulGdWAg9afak96dNOGWsGx0DLLBB1VQsAJvo6bQMTDzXoPlEHsBEw==",
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/@rc-component/menu/-/menu-1.4.1.tgz",
+      "integrity": "sha512-3GsVRoQ4cnF/AoIQ4P+Z1haBfgfBPQfLT1RJY3Nu4DzOnheTslfCiGSPj7bv/cLj5sW5pHqN25dDXGP3JELAlQ==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/motion": "^1.1.4",
@@ -1704,9 +1701,9 @@
       }
     },
     "node_modules/@rc-component/pagination": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/@rc-component/pagination/-/pagination-1.3.0.tgz",
-      "integrity": "sha512-12ahTY+HPITg1L2bjWKXUqBJe/oOnpA2QsChdCjthqLVf/e19StiCsv8OLKpWoHbc+8PFEkNjRqRqrLoRBHjFw==",
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/pagination/-/pagination-1.4.0.tgz",
+      "integrity": "sha512-CW1g7P9V8u+e8JQdUsl2RWg+GCsoee0mtJjZUCCxn/vb3jzOwDKm6hAdwddHCVBfWJ58eGUBZz3IvnU8rRktjw==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/util": "^1.11.1",
@@ -1718,15 +1715,15 @@
       }
     },
     "node_modules/@rc-component/picker": {
-      "version": "1.10.0",
-      "resolved": "https://registry.npmjs.org/@rc-component/picker/-/picker-1.10.0.tgz",
-      "integrity": "sha512-vVOXP2RVWozwpERGUFAehVH1Jz6o/uRrAb9qSZm1LC+iJs8rvEwFo1bzz2jlOYV+uWwu0dIuG86tnDui14Ea0w==",
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/picker/-/picker-1.11.0.tgz",
+      "integrity": "sha512-6qXGKtoJvO8sUd17m5cyNEbEJub0zflCHnaZTBBmj63DPRZYc0WEHN8rp6hFSl+yMCJS/dJY5G+1fQ8bLCuD7A==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/overflow": "^1.0.0",
         "@rc-component/resize-observer": "^1.0.0",
         "@rc-component/trigger": "^3.6.15",
-        "@rc-component/util": "^1.3.0",
+        "@rc-component/util": "^1.11.1",
         "clsx": "^2.1.1"
       },
       "engines": {
@@ -1849,9 +1846,9 @@
       }
     },
     "node_modules/@rc-component/select": {
-      "version": "1.7.1",
-      "resolved": "https://registry.npmjs.org/@rc-component/select/-/select-1.7.1.tgz",
-      "integrity": "sha512-GZ1cMJk2xQh0VHyOQjjG8drYL4iu24NcbkXioUcReQOCUr+ub/3fmRonZe6cRPEZhWMbJdeHsqnEltogDaZ5Tg==",
+      "version": "1.8.2",
+      "resolved": "https://registry.npmjs.org/@rc-component/select/-/select-1.8.2.tgz",
+      "integrity": "sha512-HQ9zuYqjfZTlcEMWlU1GAPBajd2OHIMVHyjZSGVTCVARwkfCgvXZMTEn0cduy3L+ejAKkaZluOQvxovZoaJaQw==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/overflow": "^1.0.0",
@@ -1869,9 +1866,9 @@
       }
     },
     "node_modules/@rc-component/slider": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/@rc-component/slider/-/slider-1.0.1.tgz",
-      "integrity": "sha512-uDhEPU1z3WDfCJhaL9jfd2ha/Eqpdfxsn0Zb0Xcq1NGQAman0TWaR37OWp2vVXEOdV2y0njSILTMpTfPV1454g==",
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/@rc-component/slider/-/slider-1.1.1.tgz",
+      "integrity": "sha512-LSzgWGYDgeCDgR4r1XlU29gbYws6HpLnvJd/uMhLeW/vQgxldeR+Wb4uzHDCHiYEbr1bnEHWdjkPxjJRHxuiig==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/util": "^1.3.0",
@@ -1937,13 +1934,13 @@
       }
     },
     "node_modules/@rc-component/tabs": {
-      "version": "1.9.1",
-      "resolved": "https://registry.npmjs.org/@rc-component/tabs/-/tabs-1.9.1.tgz",
-      "integrity": "sha512-6mY08Fce6aNOHuGsxbzT+f2ekgL9mg1cGGHkittMlVGymjGg+kGupu5v90sRxcUd/paRU9jclLLXtF/PkK1FUA==",
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/tabs/-/tabs-1.11.0.tgz",
+      "integrity": "sha512-hA/drZYOVa/MMIb4M2fWf3yaTyTG4qVuIABmghvEhyfw2nBob5VTH69lMCDjSVKmgODjO6nWlCV+gVn3xBrj5Q==",
       "license": "MIT",
       "dependencies": {
         "@rc-component/dropdown": "~1.0.0",
-        "@rc-component/menu": "~1.3.0",
+        "@rc-component/menu": "~1.4.0",
         "@rc-component/motion": "^1.1.3",
         "@rc-component/resize-observer": "^1.0.0",
         "@rc-component/util": "^1.11.1",
@@ -2011,14 +2008,14 @@
       }
     },
     "node_modules/@rc-component/tree-select": {
-      "version": "1.10.0",
-      "resolved": "https://registry.npmjs.org/@rc-component/tree-select/-/tree-select-1.10.0.tgz",
-      "integrity": "sha512-E1U4pn2LAbXEhLJdzIzid7WYbIuFbkTIctuFoeC6weppf8UbPR3+YYB6/ay0c0ksand4gXMRQpa1Z60Auo7VJA==",
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/@rc-component/tree-select/-/tree-select-1.11.0.tgz",
+      "integrity": "sha512-EhS0X0wtUhBfK4S5TlpSY3MR9ndPMGgujtt1PJW3Ej+ToAlnS/6ohYURtCoXBYGqazUwHmgQGVUDsfpVwhWPkg==",
       "license": "MIT",
       "dependencies": {
-        "@rc-component/select": "~1.7.0",
-        "@rc-component/tree": "~1.3.0",
-        "@rc-component/util": "^1.4.0",
+        "@rc-component/select": "~1.8.0",
+        "@rc-component/tree": "~1.3.2",
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       "license": "MIT",
       "dependencies": {
-        "@oxc-project/types": "=0.133.0",
+        "@oxc-project/types": "=0.138.0",
         "@rolldown/pluginutils": "^1.0.0"
       },
       "bin": {
@@ -7990,21 +7949,21 @@
         "node": "^20.19.0 || >=22.12.0"
       },
       "optionalDependencies": {
-        "@rolldown/binding-android-arm64": "1.0.3",
-        "@rolldown/binding-darwin-arm64": "1.0.3",
-        "@rolldown/binding-darwin-x64": "1.0.3",
-        "@rolldown/binding-freebsd-x64": "1.0.3",
-        "@rolldown/binding-linux-arm-gnueabihf": "1.0.3",
-        "@rolldown/binding-linux-arm64-gnu": "1.0.3",
-        "@rolldown/binding-linux-arm64-musl": "1.0.3",
-        "@rolldown/binding-linux-ppc64-gnu": "1.0.3",
-        "@rolldown/binding-linux-s390x-gnu": "1.0.3",
-        "@rolldown/binding-linux-x64-gnu": "1.0.3",
-        "@rolldown/binding-linux-x64-musl": "1.0.3",
-        "@rolldown/binding-openharmony-arm64": "1.0.3",
-        "@rolldown/binding-wasm32-wasi": "1.0.3",
-        "@rolldown/binding-win32-arm64-msvc": "1.0.3",
-        "@rolldown/binding-win32-x64-msvc": "1.0.3"
+        "@rolldown/binding-android-arm64": "1.1.4",
+        "@rolldown/binding-darwin-arm64": "1.1.4",
+        "@rolldown/binding-darwin-x64": "1.1.4",
+        "@rolldown/binding-freebsd-x64": "1.1.4",
+        "@rolldown/binding-linux-arm-gnueabihf": "1.1.4",
+        "@rolldown/binding-linux-arm64-gnu": "1.1.4",
+        "@rolldown/binding-linux-arm64-musl": "1.1.4",
+        "@rolldown/binding-linux-ppc64-gnu": "1.1.4",
+        "@rolldown/binding-linux-s390x-gnu": "1.1.4",
+        "@rolldown/binding-linux-x64-gnu": "1.1.4",
+        "@rolldown/binding-linux-x64-musl": "1.1.4",
+        "@rolldown/binding-openharmony-arm64": "1.1.4",
+        "@rolldown/binding-wasm32-wasi": "1.1.4",
+        "@rolldown/binding-win32-arm64-msvc": "1.1.4",
+        "@rolldown/binding-win32-x64-msvc": "1.1.4"
       }
     },
     "node_modules/vitest": {
diff --git a/admin-service/src/App.tsx b/admin-service/src/App.tsx
index e08256e0..5c73ebb4 100644
--- a/admin-service/src/App.tsx
+++ b/admin-service/src/App.tsx
@@ -10,7 +10,8 @@ import {
   LayoutDashboard, Users, BookOpen, Layers, FileText,
   PenTool, BarChart3, Languages, Trophy, ShoppingBag,
   Megaphone, ScrollText, Activity, Settings,
-  Shield, Database, Bot, ArrowRight, ArrowLeft, MessageSquare, Swords, Bell
+  Shield, Database, Bot, ArrowRight, ArrowLeft, MessageSquare, Swords, Bell,
+  ClipboardCheck, Gauge
 } from "lucide-react";
 
 // Lazy-loaded components
@@ -31,9 +32,11 @@ const AdsPage = lazy(() => import("./pages/AdsPage").then(m => ({ default: m.Ads
 const LogsPage = lazy(() => import("./pages/LogsPage").then(m => ({ default: m.LogsPage })));
 const MonitoringPage = lazy(() => import("./pages/MonitoringPage").then(m => ({ default: m.MonitoringPage })));
 const ContentLabPage = lazy(() => import("./pages/ContentLabPage").then(m => ({ default: m.ContentLabPage })));
+const ContentQaQueuePage = lazy(() => import("./pages/ContentQaQueuePage").then(m => ({ default: m.ContentQaQueuePage })));
 const DatabasePage = lazy(() => import("./pages/DatabasePage").then(m => ({ default: m.DatabasePage })));
 const AiModelsPage = lazy(() => import("./pages/AiModelsPage").then(m => ({ default: m.AiModelsPage })));
 const ContentAnalyticsPage = lazy(() => import("./pages/ContentAnalyticsPage").then(m => ({ default: m.ContentAnalyticsPage })));
+const AiQualityDashboardPage = lazy(() => import("./pages/AiQualityDashboardPage").then(m => ({ default: m.AiQualityDashboardPage })));
 const SystemSettingsPage = lazy(() => import("./pages/SystemSettingsPage").then(m => ({ default: m.SystemSettingsPage })));
 const AdminManagementPage = lazy(() => import("./pages/AdminManagementPage").then(m => ({ default: m.AdminManagementPage })));
 const AiChatSettingsPage = lazy(() => import("./pages/AiChatSettingsPage").then(m => ({ default: m.AiChatSettingsPage })));
@@ -60,7 +63,9 @@ const AppRoutes = () => {
     { to: "/admin/lessons", label: t.nav.lessons, icon: <FileText size={18} /> },
     { to: "/admin/topics", label: t.nav.topics, icon: <MessageSquare size={18} /> },
     { to: "/admin/content-lab", label: t.nav.grammarTest, icon: <PenTool size={18} /> },
+    { to: "/admin/content-qa", label: t.nav.contentQaQueue, icon: <ClipboardCheck size={18} /> },
     { to: "/admin/content-analytics", label: t.nav.contentAnalytics, icon: <BarChart3 size={18} /> },
+    { to: "/admin/ai-quality", label: t.nav.aiQuality, icon: <Gauge size={18} /> },
     { to: "/admin/vocabulary", label: t.nav.vocabulary, icon: <Languages size={18} /> },
     { to: "/admin/achievements", label: t.nav.achievements, icon: <Trophy size={18} /> },
     { to: "/admin/shop", label: t.nav.shop, icon: <ShoppingBag size={18} /> },
@@ -104,7 +109,9 @@ const AppRoutes = () => {
               <Route path="/admin/lessons" element={<LessonsPage />} />
               <Route path="/admin/topics" element={<TopicsPage />} />
               <Route path="/admin/content-lab" element={<ContentLabPage />} />
+              <Route path="/admin/content-qa" element={<ContentQaQueuePage />} />
               <Route path="/admin/content-analytics" element={<ContentAnalyticsPage />} />
+              <Route path="/admin/ai-quality" element={<AiQualityDashboardPage />} />
               <Route path="/admin/vocabulary" element={<VocabularyPage />} />
               <Route path="/admin/achievements" element={<AchievementsPage />} />
               <Route path="/admin/shop" element={<ShopPage />} />
diff --git a/admin-service/src/lib/adminApi.ts b/admin-service/src/lib/adminApi.ts
index d30dbfc7..ab963405 100644
--- a/admin-service/src/lib/adminApi.ts
+++ b/admin-service/src/lib/adminApi.ts
@@ -280,6 +280,8 @@ export const uploadBadgeImage = async (file: File): Promise<AdminResponse<{ url:
 // Shop Management
 // ============================================================================
 
+export type ShopItemEffects = Record<string, unknown>;
+
 export type ShopItemType = {
   id: string;
   name: string;
@@ -289,6 +291,7 @@ export type ShopItemType = {
   is_available: boolean;
   stock_quantity?: number | null;
   icon_url?: string | null;
+  effects?: ShopItemEffects | null;
 };
 
 export const listShopItems = async (includeUnavailable = true) =>
@@ -303,17 +306,19 @@ export const createShopItem = async (params: {
   price_gems: number;
   is_available?: boolean;
   stock_quantity?: number;
-}) => {
-  const url = new URL(`${ENV.backendUrl}/admin/shop`);
-  Object.entries(params).forEach(([k, v]) => { if (v !== undefined) url.searchParams.set(k, String(v)); });
-  return apiFetch<AdminResponse<ShopItemType>>(url.toString(), { method: "POST" });
-};
+  icon_url?: string;
+  effects?: ShopItemEffects;
+}) =>
+  apiFetch<AdminResponse<ShopItemType>>(`${ENV.backendUrl}/admin/shop`, {
+    method: "POST",
+    body: JSON.stringify(params),
+  });
 
-export const updateShopItem = async (id: string, params: Partial<ShopItemType>) => {
-  const url = new URL(`${ENV.backendUrl}/admin/shop/${id}`);
-  Object.entries(params).forEach(([k, v]) => { if (v !== undefined) url.searchParams.set(k, String(v)); });
-  return apiFetch<AdminResponse<ShopItemType>>(url.toString(), { method: "PUT" });
-};
+export const updateShopItem = async (id: string, params: Partial<ShopItemType>) =>
+  apiFetch<AdminResponse<ShopItemType>>(`${ENV.backendUrl}/admin/shop/${id}`, {
+    method: "PUT",
+    body: JSON.stringify(params),
+  });
 
 export const deleteShopItem = async (id: string) =>
   apiFetch<AdminResponse<{ deleted: boolean }>>(`${ENV.backendUrl}/admin/shop/${id}`, {
diff --git a/admin-service/src/lib/aiQualityApi.test.ts b/admin-service/src/lib/aiQualityApi.test.ts
new file mode 100644
index 00000000..fce6263e
--- /dev/null
+++ b/admin-service/src/lib/aiQualityApi.test.ts
@@ -0,0 +1,37 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const { apiFetchMock } = vi.hoisted(() => ({
+  apiFetchMock: vi.fn(),
+}));
+
+vi.mock("./api", () => ({
+  apiFetch: apiFetchMock,
+}));
+
+vi.mock("./env", () => ({
+  ENV: {
+    backendUrl: "https://backend.example/api/v1",
+  },
+}));
+
+import { getAiQualitySummary } from "./aiQualityApi";
+
+describe("aiQualityApi", () => {
+  beforeEach(() => {
+    apiFetchMock.mockReset();
+    apiFetchMock.mockResolvedValue({
+      events: [],
+      summary: { total_events: 0 },
+      total: 0,
+      source: "ai:audit:all",
+    });
+  });
+
+  it("loads the backend AI audit quality summary with a bounded limit", async () => {
+    await getAiQualitySummary(250);
+
+    expect(apiFetchMock).toHaveBeenCalledWith(
+      "https://backend.example/api/v1/ai-audit/quality-summary?limit=250",
+    );
+  });
+});
diff --git a/admin-service/src/lib/aiQualityApi.ts b/admin-service/src/lib/aiQualityApi.ts
new file mode 100644
index 00000000..0aae40f3
--- /dev/null
+++ b/admin-service/src/lib/aiQualityApi.ts
@@ -0,0 +1,58 @@
+import { apiFetch } from "./api";
+import { ENV } from "./env";
+
+export type AiQualityEndpointBreakdown = {
+  endpoint: string;
+  total: number;
+  failures: number;
+  average_latency_ms: number;
+};
+
+export type AiQualityFailure = {
+  request_id?: string | null;
+  user_id?: string | null;
+  endpoint?: string | null;
+  status?: string | null;
+  latency_ms?: number | null;
+  received_at?: string | null;
+  error?: string | null;
+};
+
+export type AiQualitySummary = {
+  total_events: number;
+  success_count: number;
+  failure_count: number;
+  success_rate: number;
+  average_latency_ms: number;
+  p95_latency_ms: number;
+  lexi: {
+    events: number;
+    failures: number;
+    average_latency_ms: number;
+  };
+  stt: {
+    failures: number;
+  };
+  tts: {
+    failures: number;
+  };
+  correction: {
+    events: number;
+    failures: number;
+    average_score: number;
+  };
+  endpoint_breakdown: AiQualityEndpointBreakdown[];
+  latest_failures: AiQualityFailure[];
+};
+
+export type AiQualityResponse = {
+  events: unknown[];
+  summary: AiQualitySummary;
+  total: number;
+  source: string;
+};
+
+export const getAiQualitySummary = (limit = 500) =>
+  apiFetch<AiQualityResponse>(
+    `${ENV.backendUrl}/ai-audit/quality-summary?limit=${encodeURIComponent(limit)}`,
+  );
diff --git a/admin-service/src/lib/contentAgentApi.test.ts b/admin-service/src/lib/contentAgentApi.test.ts
index 8b98c5df..8a75fff8 100644
--- a/admin-service/src/lib/contentAgentApi.test.ts
+++ b/admin-service/src/lib/contentAgentApi.test.ts
@@ -16,11 +16,13 @@ vi.mock("./env", () => ({
 
 import {
   applyContentAgentJob,
+  buildContentQaQueue,
   cancelContentAgentJob,
   createContentAgentJob,
   getContentAgentJob,
   getContentAgentPreview,
   listContentAgentJobs,
+  listContentQaQueue,
   retryContentAgentJob,
   uploadContentAgentFile,
 } from "./contentAgentApi";
@@ -121,4 +123,36 @@ describe("contentAgentApi", () => {
       total: 4,
     });
   });
+
+  it("builds a content QA queue from agent job statuses", () => {
+    const queue = buildContentQaQueue([
+      { id: "ready", status: "preview_ready" },
+      { id: "failed", status: "failed" },
+      { id: "done", status: "completed" },
+      { id: "running", status: "generating" },
+    ] as any);
+
+    expect(queue.total).toBe(4);
+    expect(queue.reviewable.map((job) => job.id)).toEqual(["ready"]);
+    expect(queue.failed.map((job) => job.id)).toEqual(["failed"]);
+    expect(queue.applied.map((job) => job.id)).toEqual(["done"]);
+  });
+
+  it("loads content QA queue through the jobs endpoint", async () => {
+    apiFetchMock.mockResolvedValueOnce({
+      data: {
+        jobs: [
+          { id: "job-1", status: "preview_ready" },
+          { id: "job-2", status: "failed" },
+        ],
+        total: 2,
+      },
+    });
+
+    await expect(listContentQaQueue()).resolves.toMatchObject({
+      reviewable: [{ id: "job-1" }],
+      failed: [{ id: "job-2" }],
+      total: 2,
+    });
+  });
 });
diff --git a/admin-service/src/lib/contentAgentApi.ts b/admin-service/src/lib/contentAgentApi.ts
index 84961aa9..b9c918f5 100644
--- a/admin-service/src/lib/contentAgentApi.ts
+++ b/admin-service/src/lib/contentAgentApi.ts
@@ -201,6 +201,13 @@ export type ContentAgentJobList = {
   total: number;
 };
 
+export type ContentQaQueue = {
+  reviewable: ContentAgentJob[];
+  failed: ContentAgentJob[];
+  applied: ContentAgentJob[];
+  total: number;
+};
+
 type ApiEnvelope<T> = {
   success?: boolean;
   data?: T;
@@ -297,6 +304,26 @@ export const listContentAgentJobs = async (): Promise<ContentAgentJobList> => {
   };
 };
 
+export const buildContentQaQueue = (
+  jobs: readonly ContentAgentJob[],
+): ContentQaQueue => {
+  const reviewable = jobs.filter((job) => job.status === "preview_ready");
+  const failed = jobs.filter((job) => job.status === "failed");
+  const applied = jobs.filter((job) => job.status === "completed");
+
+  return {
+    reviewable,
+    failed,
+    applied,
+    total: jobs.length,
+  };
+};
+
+export const listContentQaQueue = async (): Promise<ContentQaQueue> => {
+  const { jobs } = await listContentAgentJobs();
+  return buildContentQaQueue(jobs);
+};
+
 export const getContentAgentJob = async (
   jobId: string,
 ): Promise<ContentAgentJob> => {
diff --git a/admin-service/src/lib/i18n/en.ts b/admin-service/src/lib/i18n/en.ts
index 7e7781a6..e423a89a 100644
--- a/admin-service/src/lib/i18n/en.ts
+++ b/admin-service/src/lib/i18n/en.ts
@@ -67,7 +67,9 @@ const en: Translations = {
     lessons: "Lessons",
     topics: "Topics",
     grammarTest: "Grammar & Tests",
+    contentQaQueue: "Content QA",
     contentAnalytics: "Content Analytics",
+    aiQuality: "AI Quality",
     vocabulary: "Vocabulary",
     achievements: "Achievements",
     shop: "Shop",
@@ -479,6 +481,13 @@ const en: Translations = {
     stockQuantity: "Stock Quantity",
     unlimitedPlaceholder: "Leave blank = unlimited",
     updateFailed: "Update failed",
+    useTemplate: "Use Template",
+    templateApplied: "Template applied for this item type — adjust as needed before saving.",
+    iconUrl: "Icon URL",
+    iconUrlPlaceholder: "e.g. assets/icon-library/clock_freeze.png",
+    effectsLabel: "Effects (JSON)",
+    effectsHint: "e.g. {\"seconds\": 10} — determines how this item behaves in-game.",
+    effectsInvalidJson: "Effects must be valid JSON, e.g. {\"seconds\": 10}",
   },
 
   // ============== Ads/Banner ==============
diff --git a/admin-service/src/lib/i18n/vi.ts b/admin-service/src/lib/i18n/vi.ts
index 9f7edc4d..5616bdd3 100644
--- a/admin-service/src/lib/i18n/vi.ts
+++ b/admin-service/src/lib/i18n/vi.ts
@@ -65,7 +65,9 @@ const vi = {
     lessons: "Bài học",
     topics: "Topic chat",
     grammarTest: "Ngữ pháp & Kiểm tra",
+    contentQaQueue: "QA nội dung",
     contentAnalytics: "Phân tích nội dung",
+    aiQuality: "Chất lượng AI",
     vocabulary: "Từ vựng",
     achievements: "Thành tựu",
     shop: "Cửa hàng",
@@ -477,6 +479,13 @@ const vi = {
     stockQuantity: "Số lượng kho",
     unlimitedPlaceholder: "Để trống = vô hạn",
     updateFailed: "Cập nhật thất bại",
+    useTemplate: "Dùng mẫu",
+    templateApplied: "Đã điền mẫu cho loại item này — có thể chỉnh lại trước khi lưu.",
+    iconUrl: "URL icon",
+    iconUrlPlaceholder: "VD: assets/icon-library/clock_freeze.png",
+    effectsLabel: "Hiệu ứng (JSON)",
+    effectsHint: "VD: {\"seconds\": 10} — quyết định cách item này hoạt động trong game.",
+    effectsInvalidJson: "Hiệu ứng phải là JSON hợp lệ, ví dụ {\"seconds\": 10}",
   },
 
   // ============== Ads/Banner ==============
diff --git a/admin-service/src/pages/AiQualityDashboardPage.tsx b/admin-service/src/pages/AiQualityDashboardPage.tsx
new file mode 100644
index 00000000..b58735d3
--- /dev/null
+++ b/admin-service/src/pages/AiQualityDashboardPage.tsx
@@ -0,0 +1,166 @@
+import React, { useCallback, useEffect, useState } from "react";
+import { AlertTriangle, RefreshCw } from "lucide-react";
+import { DataTable } from "../components/DataTable";
+import { EmptyState } from "../components/EmptyState";
+import { SectionHeader } from "../components/SectionHeader";
+import { StatCard } from "../components/StatCard";
+import { StatusPill } from "../components/StatusPill";
+import {
+  getAiQualitySummary,
+  type AiQualityEndpointBreakdown,
+  type AiQualityFailure,
+  type AiQualityResponse,
+} from "../lib/aiQualityApi";
+
+const pctTone = (value: number): "success" | "warning" | "danger" =>
+  value >= 95 ? "success" : value >= 85 ? "warning" : "danger";
+
+export const AiQualityDashboardPage = () => {
+  const [data, setData] = useState<AiQualityResponse | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const load = useCallback(async () => {
+    setLoading(true);
+    setError(null);
+    try {
+      setData(await getAiQualitySummary(500));
+    } catch (err: any) {
+      setError(err?.message || "Failed to load AI quality metrics");
+    } finally {
+      setLoading(false);
+    }
+  }, []);
+
+  useEffect(() => {
+    void load();
+  }, [load]);
+
+  const summary = data?.summary;
+  const hasEvents = Boolean(summary?.total_events);
+
+  return (
+    <div className="stack">
+      <SectionHeader
+        title="AI Quality"
+        description="Lexi latency, correction quality, STT/TTS failures, and recent AI audit incidents."
+        action={
+          <button className="btn-secondary btn-sm" onClick={load} disabled={loading}>
+            <RefreshCw size={14} /> Refresh
+          </button>
+        }
+      />
+
+      {error && <div className="form-error">{error}</div>}
+      {loading && <div className="loading">Loading AI quality metrics...</div>}
+
+      {!loading && !hasEvents ? (
+        <EmptyState
+          icon={<AlertTriangle />}
+          title="No AI audit events yet"
+          description="Metrics will appear after ai-service starts ingesting audit events into backend-service."
+        />
+      ) : summary ? (
+        <>
+          <div className="card-grid">
+            <StatCard label="Audit events" value={String(summary.total_events)} accent="ink" note={data?.source} />
+            <StatCard label="Success rate" value={`${summary.success_rate.toFixed(1)}%`} accent="teal" />
+            <StatCard label="Avg latency" value={`${Math.round(summary.average_latency_ms)} ms`} accent="orange" />
+            <StatCard label="P95 latency" value={`${Math.round(summary.p95_latency_ms)} ms`} accent="berry" />
+          </div>
+
+          <div className="card-grid">
+            <StatCard label="Lexi events" value={String(summary.lexi.events)} note={`${summary.lexi.failures} failures`} accent="teal" />
+            <StatCard label="STT failures" value={String(summary.stt.failures)} accent="berry" />
+            <StatCard label="TTS failures" value={String(summary.tts.failures)} accent="orange" />
+            <StatCard label="Correction score" value={summary.correction.average_score ? summary.correction.average_score.toFixed(2) : "--"} note={`${summary.correction.events} events`} accent="ink" />
+          </div>
+
+          <div className="panel">
+            <h3 style={{ padding: "16px 16px 0" }}>Endpoint breakdown</h3>
+            {!summary.endpoint_breakdown.length ? (
+              <EmptyState title="No endpoint data" description="No AI endpoint events were found in the selected window." />
+            ) : (
+              <DataTable<AiQualityEndpointBreakdown>
+                rows={summary.endpoint_breakdown}
+                columns={[
+                  {
+                    header: "Endpoint",
+                    render: (row) => <span className="table-title">{row.endpoint}</span>,
+                  },
+                  {
+                    header: "Events",
+                    render: (row) => <span className="table-meta">{row.total}</span>,
+                    align: "center",
+                  },
+                  {
+                    header: "Failures",
+                    render: (row) => (
+                      <StatusPill
+                        tone={row.failures ? "danger" : "success"}
+                        label={String(row.failures)}
+                      />
+                    ),
+                    align: "center",
+                  },
+                  {
+                    header: "Avg latency",
+                    render: (row) => <span className="table-meta">{Math.round(row.average_latency_ms)} ms</span>,
+                    align: "right",
+                  },
+                ]}
+              />
+            )}
+          </div>
+
+          <div className="panel">
+            <h3 style={{ padding: "16px 16px 0" }}>Latest failures</h3>
+            {!summary.latest_failures.length ? (
+              <EmptyState title="No recent failures" description="The latest AI audit window has no failed events." />
+            ) : (
+              <DataTable<AiQualityFailure>
+                rows={summary.latest_failures}
+                columns={[
+                  {
+                    header: "Request",
+                    render: (row) => (
+                      <div>
+                        <div className="table-title">{row.request_id || "unknown"}</div>
+                        <div className="table-sub">{row.user_id || "unknown user"}</div>
+                      </div>
+                    ),
+                  },
+                  {
+                    header: "Endpoint",
+                    render: (row) => <span className="table-meta">{row.endpoint || "unknown"}</span>,
+                  },
+                  {
+                    header: "Status",
+                    render: (row) => <StatusPill tone="danger" label={row.status || "failed"} />,
+                    align: "center",
+                  },
+                  {
+                    header: "Latency",
+                    render: (row) => <span className="table-meta">{row.latency_ms ? `${Math.round(row.latency_ms)} ms` : "--"}</span>,
+                    align: "right",
+                  },
+                  {
+                    header: "Error",
+                    render: (row) => <span className="table-sub">{row.error || "No message"}</span>,
+                  },
+                ]}
+              />
+            )}
+          </div>
+
+          <div className="panel-inner">
+            <StatusPill tone={pctTone(summary.success_rate)} label={`${summary.success_rate.toFixed(1)}% success`} />
+            <span className="table-sub" style={{ marginLeft: 10 }}>
+              {summary.failure_count} failed of {summary.total_events} audited events.
+            </span>
+          </div>
+        </>
+      ) : null}
+    </div>
+  );
+};
diff --git a/admin-service/src/pages/ContentQaQueuePage.tsx b/admin-service/src/pages/ContentQaQueuePage.tsx
new file mode 100644
index 00000000..539d18ae
--- /dev/null
+++ b/admin-service/src/pages/ContentQaQueuePage.tsx
@@ -0,0 +1,272 @@
+import React, { useCallback, useEffect, useMemo, useState } from "react";
+import { CheckCircle, RefreshCw, RotateCcw, XCircle } from "lucide-react";
+import { EmptyState } from "../components/EmptyState";
+import { SectionHeader } from "../components/SectionHeader";
+import { StatCard } from "../components/StatCard";
+import { StatusPill } from "../components/StatusPill";
+import {
+  applyContentAgentJob,
+  cancelContentAgentJob,
+  getContentAgentPreview,
+  listContentQaQueue,
+  retryContentAgentJob,
+  type ContentAgentJob,
+  type ContentAgentPreview,
+  type ContentQaQueue,
+} from "../lib/contentAgentApi";
+
+const statusTone = (status: string): "success" | "warning" | "info" | "danger" | "neutral" => {
+  if (status === "preview_ready") return "warning";
+  if (status === "completed") return "success";
+  if (status === "failed") return "danger";
+  return "info";
+};
+
+const summarizePreview = (preview: ContentAgentPreview | null) => {
+  if (!preview) {
+    return { courses: 0, units: 0, lessons: 0, vocabulary: 0, exercises: 0 };
+  }
+
+  return preview.courses.reduce(
+    (acc, course) => {
+      acc.courses += 1;
+      acc.units += course.units.length;
+      course.units.forEach((unit) => {
+        acc.lessons += unit.lessons.length;
+        unit.lessons.forEach((lesson) => {
+          acc.vocabulary += lesson.vocabulary.length;
+          acc.exercises += lesson.exercises.length;
+        });
+      });
+      return acc;
+    },
+    { courses: 0, units: 0, lessons: 0, vocabulary: 0, exercises: 0 },
+  );
+};
+
+const JobList = ({
+  title,
+  jobs,
+  selectedId,
+  onSelect,
+}: {
+  title: string;
+  jobs: ContentAgentJob[];
+  selectedId?: string;
+  onSelect: (job: ContentAgentJob) => void;
+}) => (
+  <div className="panel-inner">
+    <h3>{title}</h3>
+    {!jobs.length ? (
+      <EmptyState title="No jobs" description="Nothing is waiting in this bucket." />
+    ) : (
+      <div className="stack" style={{ gap: 10 }}>
+        {jobs.map((job) => (
+          <button
+            key={job.id}
+            className={selectedId === job.id ? "ghost-button active" : "ghost-button"}
+            onClick={() => onSelect(job)}
+            style={{
+              justifyContent: "space-between",
+              textAlign: "left",
+              width: "100%",
+              borderColor: selectedId === job.id ? "var(--accent-2)" : undefined,
+            }}
+          >
+            <span>
+              <strong>{job.config.title_focus || job.config.levels?.join(", ") || "Content job"}</strong>
+              <span className="table-sub" style={{ display: "block" }}>
+                {job.id.slice(0, 8)} · {new Date(job.updated_at).toLocaleString()}
+              </span>
+            </span>
+            <StatusPill tone={statusTone(job.status)} label={job.status} />
+          </button>
+        ))}
+      </div>
+    )}
+  </div>
+);
+
+export const ContentQaQueuePage = () => {
+  const [queue, setQueue] = useState<ContentQaQueue | null>(null);
+  const [selected, setSelected] = useState<ContentAgentJob | null>(null);
+  const [preview, setPreview] = useState<ContentAgentPreview | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [previewLoading, setPreviewLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const loadQueue = useCallback(async () => {
+    setLoading(true);
+    setError(null);
+    try {
+      const nextQueue = await listContentQaQueue();
+      setQueue(nextQueue);
+      setSelected((current) => {
+        const jobs = [
+          ...nextQueue.reviewable,
+          ...nextQueue.failed,
+          ...nextQueue.applied,
+        ];
+        return (
+          (current ? jobs.find((job) => job.id === current.id) : null) ??
+          nextQueue.reviewable[0] ??
+          nextQueue.failed[0] ??
+          nextQueue.applied[0] ??
+          null
+        );
+      });
+    } catch (err: any) {
+      setError(err?.message || "Failed to load content QA queue");
+    } finally {
+      setLoading(false);
+    }
+  }, []);
+
+  useEffect(() => {
+    void loadQueue();
+  }, [loadQueue]);
+
+  useEffect(() => {
+    if (!selected) {
+      setPreview(null);
+      return;
+    }
+
+    setPreviewLoading(true);
+    getContentAgentPreview(selected.id)
+      .then(setPreview)
+      .catch(() => setPreview(null))
+      .finally(() => setPreviewLoading(false));
+  }, [selected]);
+
+  const summary = useMemo(() => summarizePreview(preview), [preview]);
+  const validationErrors = [
+    ...(selected?.blocking_errors || []),
+    ...(preview?.quality.blocking_errors || []),
+  ];
+  const validationWarnings = [
+    ...(selected?.warnings || []),
+    ...(preview?.quality.warnings || []),
+  ];
+  const createdCourseIds =
+    selected?.created_entity_ids.course_ids ??
+    selected?.created_entity_ids.courses ??
+    [];
+
+  const runAction = async (action: "apply" | "cancel" | "retry") => {
+    if (!selected) return;
+    setError(null);
+    try {
+      if (action === "apply") await applyContentAgentJob(selected.id);
+      if (action === "cancel") await cancelContentAgentJob(selected.id);
+      if (action === "retry") await retryContentAgentJob(selected.id);
+      await loadQueue();
+    } catch (err: any) {
+      setError(err?.message || `Failed to ${action} content job`);
+    }
+  };
+
+  return (
+    <div className="stack">
+      <SectionHeader
+        title="Content QA Queue"
+        description="Review, validate, publish, or reject AI-generated learning content."
+        action={
+          <button className="btn-secondary btn-sm" onClick={loadQueue} disabled={loading}>
+            <RefreshCw size={14} /> Refresh
+          </button>
+        }
+      />
+
+      {error && <div className="form-error">{error}</div>}
+
+      <div className="card-grid">
+        <StatCard label="Ready for review" value={String(queue?.reviewable.length || 0)} accent="orange" />
+        <StatCard label="Failed validation" value={String(queue?.failed.length || 0)} accent="berry" />
+        <StatCard label="Published jobs" value={String(queue?.applied.length || 0)} accent="teal" />
+        <StatCard label="Tracked jobs" value={String(queue?.total || 0)} accent="ink" />
+      </div>
+
+      <div className="grid-2">
+        <div className="stack">
+          <JobList title="Needs approval" jobs={queue?.reviewable || []} selectedId={selected?.id} onSelect={setSelected} />
+          <JobList title="Needs repair" jobs={queue?.failed || []} selectedId={selected?.id} onSelect={setSelected} />
+          <JobList title="Apply history" jobs={queue?.applied || []} selectedId={selected?.id} onSelect={setSelected} />
+        </div>
+
+        <div className="panel">
+          {!selected ? (
+            <EmptyState title="No content job selected" description="Create a content-agent job, then review it here before publishing." />
+          ) : (
+            <div className="stack">
+              <div style={{ display: "flex", justifyContent: "space-between", gap: 12, alignItems: "center" }}>
+                <div>
+                  <h3 style={{ margin: 0 }}>{selected.config.title_focus || "Generated content preview"}</h3>
+                  <div className="table-sub">{selected.id}</div>
+                </div>
+                <StatusPill tone={statusTone(selected.status)} label={selected.status} />
+              </div>
+
+              <div className="card-grid">
+                <StatCard label="Courses" value={String(summary.courses)} accent="orange" />
+                <StatCard label="Lessons" value={String(summary.lessons)} accent="teal" />
+                <StatCard label="Vocabulary" value={String(summary.vocabulary)} accent="ink" />
+                <StatCard label="Exercises" value={String(summary.exercises)} accent="berry" />
+              </div>
+
+              <div className="panel-inner">
+                <h3>Validation</h3>
+                {previewLoading && <div className="loading">Loading preview...</div>}
+                {!validationErrors.length && !validationWarnings.length ? (
+                  <StatusPill tone="success" label="No blocking issues" />
+                ) : (
+                  <div className="stack" style={{ gap: 8 }}>
+                    {validationErrors.map((message, index) => (
+                      <div key={`error-${index}`} className="form-error">{message}</div>
+                    ))}
+                    {validationWarnings.map((message, index) => (
+                      <div key={`warning-${index}`} className="callout warning">{message}</div>
+                    ))}
+                  </div>
+                )}
+              </div>
+
+              <div className="panel-inner">
+                <h3>Source policy</h3>
+                {!preview?.source_manifest?.length ? (
+                  <div className="table-sub">No source manifest attached.</div>
+                ) : (
+                  <div className="stack" style={{ gap: 8 }}>
+                    {preview.source_manifest.map((source, index) => (
+                      <div key={`${source.source_name}-${index}`} className="table-sub">
+                        <strong>{source.source_name}</strong> · {source.license_mode || "unknown"} · {source.record_count || 0} records
+                      </div>
+                    ))}
+                  </div>
+                )}
+              </div>
+
+              <div className="panel-inner">
+                <h3>Apply history</h3>
+                <div className="table-sub">Created courses: {createdCourseIds.length ? createdCourseIds.join(", ") : "none yet"}</div>
+                <div className="table-sub">Completed: {selected.completed_at ? new Date(selected.completed_at).toLocaleString() : "not completed"}</div>
+              </div>
+
+              <div style={{ display: "flex", gap: 10, flexWrap: "wrap" }}>
+                <button className="primary-button" disabled={selected.status !== "preview_ready"} onClick={() => runAction("apply")}>
+                  <CheckCircle size={16} /> Approve & publish
+                </button>
+                <button className="ghost-button danger" disabled={!["preview_ready", "failed"].includes(selected.status)} onClick={() => runAction("cancel")}>
+                  <XCircle size={16} /> Reject
+                </button>
+                <button className="ghost-button" disabled={selected.status !== "failed"} onClick={() => runAction("retry")}>
+                  <RotateCcw size={16} /> Retry
+                </button>
+              </div>
+            </div>
+          )}
+        </div>
+      </div>
+    </div>
+  );
+};
diff --git a/admin-service/src/pages/ShopPage.tsx b/admin-service/src/pages/ShopPage.tsx
index a63b4bb2..c3a58262 100644
--- a/admin-service/src/pages/ShopPage.tsx
+++ b/admin-service/src/pages/ShopPage.tsx
@@ -12,7 +12,75 @@ import {
 } from "../lib/adminApi";
 import { useI18n } from "../lib/i18n";
 
-const ITEM_TYPES = ["streak_freeze", "double_xp", "hint_pack", "cosmetic", "power_up", "time_boost"];
+// Mirrors the item_type values actually seeded in backend-service/app/core/shop_catalog.py.
+const ITEM_TYPES = [
+  // Boosts
+  "streak_freeze",
+  "double_xp",
+  "hint_pack",
+  "heart_refill",
+  // Cosmetics
+  "avatar",
+  "theme",
+  // In-game power-ups
+  "time_freeze",
+  "extra_time",
+  "skip_token",
+  "reveal_hint",
+  "translate_hint",
+  "mistake_shield",
+  "extra_heart",
+  "lucky_clover",
+  "score_multiplier",
+  "pair_swap",
+];
+
+// Quick-create templates mirroring backend-service/app/core/shop_catalog.py, so
+// picking an item_type fills in a sensible, already-working default instead of
+// the admin having to know each item's expected effects payload shape by heart.
+const ITEM_TYPE_TEMPLATES: Record<
+  string,
+  { name: string; description: string; price_gems: number; effects: Record<string, unknown> }
+> = {
+  streak_freeze: { name: "Streak Freeze", description: "Add one streak freeze", price_gems: 25, effects: { quantity: 1 } },
+  double_xp: { name: "Double XP (1 hour)", description: "Earn double XP for 1 hour", price_gems: 25, effects: { duration_hours: 1, multiplier: 2 } },
+  hint_pack: { name: "Hint Pack (5)", description: "Add 5 hints to your active lesson", price_gems: 12, effects: { quantity: 5 } },
+  heart_refill: { name: "Heart Refill", description: "Restore your active lesson to 3 hearts", price_gems: 15, effects: { hearts: 3 } },
+  avatar: { name: "New Avatar", description: "Exclusive profile avatar", price_gems: 50, effects: { avatar_url: "" } },
+  theme: { name: "New Theme", description: "Unlockable app theme", price_gems: 50, effects: {} },
+  time_freeze: { name: "Time Freeze", description: "Pause the countdown timer for 10 seconds in any timed game", price_gems: 10, effects: { seconds: 10 } },
+  extra_time: { name: "Extra Time", description: "Add 20 seconds straight to the clock in any timed game", price_gems: 15, effects: { seconds: 20 } },
+  skip_token: { name: "Skip Token", description: "Skip the current word or question with no penalty", price_gems: 12, effects: {} },
+  reveal_hint: { name: "Magnifying Glass", description: "Free reveal: the next letter, or eliminate 2 wrong options", price_gems: 8, effects: { mode: "letter" } },
+  translate_hint: { name: "Quick Translate", description: "Reveal the Vietnamese translation of the current word", price_gems: 8, effects: { mode: "translation" } },
+  mistake_shield: { name: "Shield", description: "Negate the next wrong answer or life loss", price_gems: 18, effects: {} },
+  extra_heart: { name: "Extra Heart", description: "Start Hangman with one extra life", price_gems: 15, effects: { lives: 1 } },
+  lucky_clover: { name: "Lucky Clover", description: "30% chance to auto-correct your next wrong answer", price_gems: 20, effects: { chance: 0.3 } },
+  score_multiplier: { name: "Score Multiplier", description: "Double your in-game score for the rest of this session", price_gems: 22, effects: { multiplier: 2 } },
+  pair_swap: { name: "Pair Swap", description: "Undo one wrong match in Matching Game for a free retry", price_gems: 10, effects: {} },
+};
+
+type ShopItemForm = {
+  name: string;
+  description: string;
+  item_type: string;
+  price_gems: number;
+  is_available: boolean;
+  stock_quantity: number | undefined;
+  icon_url: string;
+  effectsText: string;
+};
+
+const EMPTY_FORM: ShopItemForm = {
+  name: "",
+  description: "",
+  item_type: "streak_freeze",
+  price_gems: 50,
+  is_available: true,
+  stock_quantity: undefined,
+  icon_url: "",
+  effectsText: "{}",
+};
 
 export const ShopPage = () => {
   const { t } = useI18n();
@@ -24,20 +92,29 @@ export const ShopPage = () => {
   const [showForm, setShowForm] = useState(false);
   const [editingId, setEditingId] = useState<string | null>(null);
   const [saving, setSaving] = useState(false);
-  const [form, setForm] = useState({
-    name: "",
-    description: "",
-    item_type: "streak_freeze",
-    price_gems: 50,
-    is_available: true,
-    stock_quantity: undefined as number | undefined,
-  });
+  const [effectsError, setEffectsError] = useState<string | null>(null);
+  const [form, setForm] = useState<ShopItemForm>(EMPTY_FORM);
 
   const resetForm = () => {
-    setForm({ name: "", description: "", item_type: "streak_freeze", price_gems: 50, is_available: true, stock_quantity: undefined });
+    setForm(EMPTY_FORM);
+    setEffectsError(null);
     setEditingId(null);
   };
 
+  const applyTemplate = (itemType: string) => {
+    const template = ITEM_TYPE_TEMPLATES[itemType];
+    if (!template) return;
+    setForm((prev) => ({
+      ...prev,
+      item_type: itemType,
+      name: template.name,
+      description: template.description,
+      price_gems: template.price_gems,
+      effectsText: JSON.stringify(template.effects, null, 2),
+    }));
+    setEffectsError(null);
+  };
+
   const loadItems = async () => {
     setLoading(true);
     setError(null);
@@ -62,12 +139,25 @@ export const ShopPage = () => {
       price_gems: item.price_gems,
       is_available: item.is_available,
       stock_quantity: item.stock_quantity ?? undefined,
+      icon_url: item.icon_url ?? "",
+      effectsText: JSON.stringify(item.effects ?? {}, null, 2),
     });
+    setEffectsError(null);
     setShowForm(true);
   };
 
   const handleSave = async (e: React.FormEvent) => {
     e.preventDefault();
+
+    let effects: Record<string, unknown> | undefined;
+    try {
+      effects = form.effectsText.trim() ? JSON.parse(form.effectsText) : {};
+    } catch {
+      setEffectsError(t.shop.effectsInvalidJson);
+      return;
+    }
+    setEffectsError(null);
+
     setSaving(true);
     setError(null);
     try {
@@ -78,9 +168,20 @@ export const ShopPage = () => {
           price_gems: form.price_gems,
           is_available: form.is_available,
           stock_quantity: form.stock_quantity ?? undefined,
+          icon_url: form.icon_url || undefined,
+          effects,
         });
       } else {
-        await createShopItem(form);
+        await createShopItem({
+          name: form.name,
+          description: form.description,
+          item_type: form.item_type,
+          price_gems: form.price_gems,
+          is_available: form.is_available,
+          stock_quantity: form.stock_quantity,
+          icon_url: form.icon_url || undefined,
+          effects,
+        });
       }
       resetForm();
       setShowForm(false);
@@ -197,9 +298,31 @@ export const ShopPage = () => {
       {/* Create/Edit Modal */}
       {showForm && (
         <div className="modal-overlay" onClick={() => setShowForm(false)}>
-          <div className="modal-content" onClick={(e) => e.stopPropagation()} style={{ maxWidth: 520 }}>
+          <div className="modal-content" onClick={(e) => e.stopPropagation()} style={{ maxWidth: 560 }}>
             <h3>{editingId ? t.shop.editItem : t.shop.createNew}</h3>
             <form className="form" onSubmit={handleSave}>
+              <div className="form-row">
+                <label style={{ flex: 1 }}>
+                  {t.shop.itemTypeRequired}
+                  <select
+                    value={form.item_type}
+                    disabled={!!editingId}
+                    onChange={(e) => setForm({ ...form, item_type: e.target.value })}
+                  >
+                    {ITEM_TYPES.map((it) => <option key={it} value={it}>{it}</option>)}
+                  </select>
+                </label>
+                {!editingId && (
+                  <button
+                    type="button"
+                    className="ghost-button"
+                    style={{ alignSelf: "flex-end" }}
+                    onClick={() => applyTemplate(form.item_type)}
+                  >
+                    {t.shop.useTemplate}
+                  </button>
+                )}
+              </div>
               <label>
                 {t.shop.nameRequired}
                 <input value={form.name} onChange={(e) => setForm({ ...form, name: e.target.value })} required />
@@ -209,18 +332,10 @@ export const ShopPage = () => {
                 <textarea rows={2} value={form.description} onChange={(e) => setForm({ ...form, description: e.target.value })} required />
               </label>
               <div className="form-row">
-                <label>
-                  {t.shop.itemTypeRequired}
-                  <select value={form.item_type} onChange={(e) => setForm({ ...form, item_type: e.target.value })}>
-                    {ITEM_TYPES.map((it) => <option key={it} value={it}>{it}</option>)}
-                  </select>
-                </label>
                 <label>
                   {t.shop.priceRequired}
                   <input type="number" min={0} value={form.price_gems} onChange={(e) => setForm({ ...form, price_gems: Number(e.target.value) })} required />
                 </label>
-              </div>
-              <div className="form-row">
                 <label>
                   {t.shop.stockQuantity}
                   <input
@@ -231,15 +346,37 @@ export const ShopPage = () => {
                     onChange={(e) => setForm({ ...form, stock_quantity: e.target.value ? Number(e.target.value) : undefined })}
                   />
                 </label>
-                <label style={{ display: "flex", alignItems: "center", gap: 8, paddingTop: 24 }}>
-                  <input
-                    type="checkbox"
-                    checked={form.is_available}
-                    onChange={(e) => setForm({ ...form, is_available: e.target.checked })}
-                  />
-                  {t.shop.onSale}
-                </label>
               </div>
+              <label>
+                {t.shop.iconUrl}
+                <input
+                  value={form.icon_url}
+                  placeholder={t.shop.iconUrlPlaceholder}
+                  onChange={(e) => setForm({ ...form, icon_url: e.target.value })}
+                />
+              </label>
+              <label>
+                {t.shop.effectsLabel}
+                <textarea
+                  rows={3}
+                  style={{ fontFamily: "monospace" }}
+                  value={form.effectsText}
+                  onChange={(e) => { setForm({ ...form, effectsText: e.target.value }); setEffectsError(null); }}
+                />
+              </label>
+              {effectsError ? (
+                <div className="form-error">{effectsError}</div>
+              ) : (
+                <div className="table-sub">{t.shop.effectsHint}</div>
+              )}
+              <label style={{ display: "flex", alignItems: "center", gap: 8 }}>
+                <input
+                  type="checkbox"
+                  checked={form.is_available}
+                  onChange={(e) => setForm({ ...form, is_available: e.target.checked })}
+                />
+                {t.shop.onSale}
+              </label>
               <div style={{ display: "flex", gap: 8, justifyContent: "flex-end" }}>
                 <button className="ghost-button" type="button" onClick={() => setShowForm(false)}>{t.common.cancel}</button>
                 <button className="primary-button" type="submit" disabled={saving}>
diff --git a/ai-service/api/core/groq_key_pool.py b/ai-service/api/core/groq_key_pool.py
index 0e9f3754..1f88e7dd 100644
--- a/ai-service/api/core/groq_key_pool.py
+++ b/ai-service/api/core/groq_key_pool.py
@@ -69,6 +69,8 @@ async def record_usage(self, api_key: str, tokens_used: int) -> None:
 
 
 _pool_instance: Optional[GroqKeyPool] = None
+_fallback_keys: Optional[List[str]] = None
+_fallback_cursor = 0
 
 
 def get_groq_key_pool() -> Optional[GroqKeyPool]:
@@ -76,18 +78,44 @@ def get_groq_key_pool() -> Optional[GroqKeyPool]:
     return _pool_instance
 
 
+def _get_fallback_keys() -> List[str]:
+    """All configured Groq keys, used when the Redis-backed pool isn't built
+    (e.g. standalone scripts that never call build_groq_key_pool)."""
+    global _fallback_keys
+    if _fallback_keys is None:
+        raw = os.getenv("GROQ_API_KEYS", "").strip() or os.getenv("GROQ_API_KEY", "").strip()
+        _fallback_keys = [k.strip() for k in raw.split(",") if k.strip()]
+    return _fallback_keys
+
+
+def get_configured_key_count() -> int:
+    """Number of usable Groq keys, whether or not the Redis pool is initialized."""
+    pool = get_groq_key_pool()
+    return pool.count if pool else len(_get_fallback_keys())
+
+
 async def get_available_groq_key(estimated_tokens: int = 600) -> Optional[str]:
     """
     Get the next available Groq API key from the pool.
-    Falls back to the single GROQ_API_KEY environment variable if pool is empty/disabled.
+    Falls back to round-robin over all configured GROQ_API_KEYS when the
+    Redis-backed pool isn't initialized — without this, callers like the
+    standalone benchmark CLI always got the same single key back and burned
+    through one account's daily quota while the rest of the pool sat idle.
     """
+    global _fallback_cursor
     pool = get_groq_key_pool()
     if pool:
         slot = await pool.get_available(estimated_tokens)
         if slot:
             api_key, _ = slot
             return api_key
-    return os.getenv("GROQ_API_KEY", "").strip() or None
+
+    keys = _get_fallback_keys()
+    if not keys:
+        return None
+    key = keys[_fallback_cursor % len(keys)]
+    _fallback_cursor += 1
+    return key
 
 
 async def record_groq_key_usage(api_key: str, tokens_used: int) -> None:
diff --git a/ai-service/api/core/redis_client.py b/ai-service/api/core/redis_client.py
index 814e4f38..1418df7d 100644
--- a/ai-service/api/core/redis_client.py
+++ b/ai-service/api/core/redis_client.py
@@ -35,6 +35,13 @@ def _benchmark_fail_fast(cls) -> bool:
         value = os.getenv("BENCHMARK_REDIS_FAIL_FAST", "")
         return value.lower() in {"1", "true", "yes", "on"}
 
+    @classmethod
+    def _benchmark_redis_disabled(cls) -> bool:
+        value = os.getenv("BENCHMARK_REDIS_DISABLED")
+        if value is not None and value.strip():
+            return value.lower() in {"1", "true", "yes", "on"}
+        return cls._benchmark_fail_fast()
+
     @classmethod
     def _effective_max_retries(cls) -> int:
         if cls._benchmark_fail_fast():
@@ -111,6 +118,10 @@ async def reconnect(cls) -> redis.Redis:
 
         Raises RuntimeError after retry budget is exhausted.
         """
+        if cls._benchmark_redis_disabled():
+            await cls._reset()
+            raise RuntimeError("Redis disabled for benchmark")
+
         last_exc: Optional[Exception] = None
         max_retries = cls._effective_max_retries()
         for attempt in range(1, max_retries + 1):
@@ -135,6 +146,10 @@ async def reconnect(cls) -> redis.Redis:
     @classmethod
     async def get_instance(cls) -> redis.Redis:
         """Get Redis instance; auto-reconnect up to retry budget when unhealthy."""
+        if cls._benchmark_redis_disabled():
+            await cls._reset()
+            raise RuntimeError("Redis disabled for benchmark")
+
         if cls._instance is None:
             return await cls.reconnect()
 
diff --git a/ai-service/api/routes/content_agent.py b/ai-service/api/routes/content_agent.py
index 387b68fe..c3a9f995 100644
--- a/ai-service/api/routes/content_agent.py
+++ b/ai-service/api/routes/content_agent.py
@@ -132,7 +132,7 @@ async def ingest_records(
         ) from exc
     except (SourcePolicyError, ValueError) as exc:
         raise HTTPException(
-            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
             detail=str(exc),
         ) from exc
     except RuntimeError as exc:
@@ -161,7 +161,7 @@ async def generate_artifact(
         ) from exc
     except InsufficientVocabularyError as exc:
         raise HTTPException(
-            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
             detail=str(exc),
         ) from exc
     except RuntimeError as exc:
@@ -261,7 +261,7 @@ async def attach_snapshots(
         ) from exc
     except (StorageIntegrityError, ValueError) as exc:
         raise HTTPException(
-            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
             detail=str(exc),
         ) from exc
     except Exception as exc:
diff --git a/ai-service/api/routes/lexi_chat.py b/ai-service/api/routes/lexi_chat.py
index 7ea72536..3416d791 100644
--- a/ai-service/api/routes/lexi_chat.py
+++ b/ai-service/api/routes/lexi_chat.py
@@ -10,27 +10,23 @@
 
 Integrates with the existing TraceCAG system for document retrieval
 and knowledge graph expansion to make conversations contextually rich.
+
+The actual pipeline orchestration (session bootstrap, STT/TraceCAG/TTS,
+persistence) lives in api.services.lexi_chat_service — this module only
+parses requests, enforces auth/quota, and shapes responses.
 """
 
 import asyncio
 import logging
-import os
-import json
-import uuid
 import time
-import base64
-import hashlib
-from contextlib import suppress
-from dataclasses import dataclass, field
+import uuid
 from datetime import datetime, timezone
-from typing import AsyncGenerator, Optional, List, Dict, Any
+from typing import Dict, Any
 
 from fastapi import APIRouter, HTTPException, Depends, Query, Header, Request
 from fastapi.responses import StreamingResponse
 from motor.motor_asyncio import AsyncIOMotorDatabase
-from bson import ObjectId
 from pymongo.errors import OperationFailure
-from pydantic import BaseModel, Field
 from api.core.auth import AuthenticatedUser, enforce_user_scope, get_current_user
 from api.core.audit_emitter import emit_ai_audit_event
 from api.core.quota_guard import default_token_cost_for_endpoint, enforce_user_quota
@@ -42,55 +38,21 @@
     load_full_cursor,
     to_iso_timestamp,
 )
-from api.services.lexi_session_store import LexiSessionStore, get_lexi_store
-from api.services.lexi_idempotency_store import LexiIdempotencyStore, get_lexi_idempotency_store
-from api.services.lexi_pipeline_helpers import (
-    sanitize_lexi_response as _sanitize_lexi_response,
-    synthesize_tts as _synthesize_tts,
-    transcribe_audio as _transcribe_audio,
+from api.services import lexi_chat_service as svc
+from api.services.lexi_chat_service import (
+    LexiChatRequest,
+    LexiChatResponse,
+    LexiSessionListResponse,
+    LexiSessionRenameRequest,
+    LexiSessionRequest,
+    LexiSessionResponse,
+    LexiSessionSummary,
 )
 
 logger = logging.getLogger(__name__)
 
 router = APIRouter(prefix="/api/v1/lexi", tags=["lexi-chat"])
 
-_store: LexiSessionStore = get_lexi_store()
-_idempotency_store: LexiIdempotencyStore = get_lexi_idempotency_store()
-
-SAFE_FIXED_RESPONSE = (
-    "Squawk! I'm temporarily unavailable right now. "
-    "Please try again in a moment."
-)
-
-# SSE stream settings
-_STREAM_PIPELINE_TIMEOUT_S = 50   # cancel and error if pipeline exceeds this
-_HEARTBEAT_INTERVAL_S = 2.5       # how often to send ": ping" keep-alive comments
-
-
-def _env_float(name: str, default: float, minimum: float = 0.0) -> float:
-    raw = os.getenv(name)
-    if raw is None:
-        return default
-    try:
-        return max(minimum, float(raw))
-    except ValueError:
-        return default
-
-
-def _idempotency_request_hash(request: "LexiChatRequest") -> str:
-    payload = {
-        "user_id": request.user_id,
-        "session_id": request.session_id,
-        "message": request.message,
-        "input_type": request.input_type,
-        "audio_base64": request.audio_base64,
-        "enable_tts": request.enable_tts,
-        "learner_level": request.learner_level,
-        "story_context": request.story_context,
-    }
-    normalized = json.dumps(payload, sort_keys=True, separators=(",", ":"))
-    return hashlib.sha256(normalized.encode("utf-8")).hexdigest()
-
 
 def _serialize_lexi_message(doc: Dict[str, Any]) -> Dict[str, Any]:
     return {
@@ -102,502 +64,6 @@ def _serialize_lexi_message(doc: Dict[str, Any]) -> Dict[str, Any]:
     }
 
 
-async def _ensure_session_owner(
-    session_id: str,
-    current_user: AuthenticatedUser,
-    db: AsyncIOMotorDatabase,
-) -> Dict[str, Any]:
-    session_doc = await db["lexi_sessions"].find_one({"session_id": session_id})
-    if not session_doc:
-        raise HTTPException(status_code=404, detail="Session not found")
-
-    owner_user_id = str(session_doc.get("user_id") or "")
-    if owner_user_id and owner_user_id != current_user.user_id:
-        raise HTTPException(status_code=403, detail="Forbidden: session ownership mismatch")
-    return session_doc
-
-
-def _assert_cached_session_owner(
-    cached_session: Dict[str, Any] | None,
-    current_user: AuthenticatedUser,
-) -> None:
-    if not cached_session:
-        return
-    owner_user_id = str(cached_session.get("user_id") or "")
-    if owner_user_id and owner_user_id != current_user.user_id:
-        raise HTTPException(status_code=403, detail="Forbidden: session ownership mismatch")
-
-
-async def _get_cached_session_with_messages(
-    session_id: str,
-) -> tuple[Dict[str, Any] | None, List[Dict[str, Any]]]:
-    if callable(getattr(type(_store), "get_session_with_messages", None)):
-        return await _store.get_session_with_messages(session_id)
-
-    cached_session, cached_messages = await asyncio.gather(
-        _store.get_session(session_id),
-        _store.get_messages(session_id),
-    )
-    return cached_session, cached_messages
-
-
-async def _prepare_existing_lexi_session(
-    session_id: str,
-    current_user: AuthenticatedUser,
-    db: AsyncIOMotorDatabase,
-) -> List[Dict[str, Any]]:
-    cached_session, cached_messages = await _get_cached_session_with_messages(session_id)
-    cached_owner = str((cached_session or {}).get("user_id") or "")
-    if cached_session and cached_owner:
-        _assert_cached_session_owner(cached_session, current_user)
-        return cached_messages
-
-    try:
-        await _ensure_session_owner(session_id, current_user, db)
-    except HTTPException as exc:
-        if exc.status_code != 404:
-            raise
-        _assert_cached_session_owner(cached_session, current_user)
-        if not cached_session:
-            raise
-        return cached_messages
-
-    _assert_cached_session_owner(cached_session, current_user)
-    if cached_session:
-        return cached_messages
-
-    docs = await (
-        db["lexi_messages"]
-        .find({"session_id": session_id})
-        .sort("timestamp", -1)
-        .limit(10)
-        .to_list(length=10)
-    )
-    docs.reverse()
-    return [
-        {
-            "id": doc.get("id") or doc.get("message_id") or str(doc.get("_id", "")),
-            "role": doc.get("role", "user"),
-            "content": doc.get("content", ""),
-            "timestamp": to_iso_timestamp(doc.get("timestamp")),
-        }
-        for doc in docs
-    ]
-
-
-async def _create_lexi_session_for_user(
-    session_id: str,
-    user_id: str,
-    story_context: Optional[str],
-    db: AsyncIOMotorDatabase,
-) -> None:
-    now_iso = datetime.now(timezone.utc).isoformat()
-    await asyncio.gather(
-        _store.set_session(session_id, {
-            "session_id": session_id,
-            "user_id": user_id,
-            "created_at": now_iso,
-            "updated_at": now_iso,
-            "title": "Lexi Chat",
-            "message_count": 0,
-            "persona": "lexi",
-            "story_context": story_context,
-        }),
-        _store.init_messages(session_id),
-        db["lexi_sessions"].update_one(
-            {"session_id": session_id},
-            {
-                "$set": {
-                    "session_id": session_id,
-                    "user_id": user_id,
-                    "title": "Lexi Chat",
-                    "created_at": now_iso,
-                    "updated_at": now_iso,
-                    "message_count": 0,
-                    "persona": "lexi",
-                }
-            },
-            upsert=True,
-        ),
-    )
-
-
-async def _append_lexi_messages(
-    session_id: str,
-    messages: List[Dict[str, Any]],
-) -> None:
-    if callable(getattr(type(_store), "append_messages", None)):
-        await _store.append_messages(session_id, messages)
-        return
-
-    await asyncio.gather(
-        *(_store.append_message(session_id, message) for message in messages)
-    )
-
-
-# ─── Lexi Persona System Prompt ─────────────────────────────────────────────
-LEXI_PERSONA = """You are Lexi, a cheerful, witty parrot who is an expert English tutor.
-You speak in a warm, encouraging tone — like a fun game character guiding an adventure.
-
-Personality traits:
-- Playful and humorous, but always educational
-- Uses short, clear sentences appropriate to the learner's level
-- Celebrates small victories with enthusiasm ("Squawk! Great job! ")
-- Gently corrects mistakes with encouraging context
-- Occasionally drops parrot-themed phrases ("Polly wants proper grammar!")
-- Adapts difficulty based on learner's CEFR level
-- Keeps conversations flowing like a story / adventure
-
-Story context rules:
-- Each conversation is an "adventure" with Lexi
-- Reference previous topics to build continuity
-- Use the knowledge graph context to teach related concepts
-- When the learner makes errors, weave corrections into the story naturally
-
-Response format:
-- Keep responses concise (2-4 sentences for dialogue)
-- Use markdown for emphasis when helpful
-- Include a gentle correction if errors are found
-- Always end with something that invites the learner to continue
-"""
-
-
-# ─── Request / Response Models ───────────────────────────────────────────────
-class LexiChatRequest(BaseModel):
-    """Request to chat with Lexi."""
-    user_id: str = Field(default="demo_user", description="User identifier")
-    session_id: Optional[str] = Field(default=None, description="Existing session ID")
-    message: str = Field(..., min_length=1, description="User message text")
-    input_type: str = Field(default="text", description="'text' or 'voice'")
-    audio_base64: Optional[str] = Field(default=None, description="Base64 audio for STT")
-    enable_tts: bool = Field(default=True, description="Generate TTS audio response")
-    learner_level: str = Field(default="B1", description="CEFR level: A1-C2")
-    story_context: Optional[str] = Field(default=None, description="Story/adventure context")
-
-
-class LexiCorrection(BaseModel):
-    """A grammar/vocabulary correction."""
-    error_span: str = ""
-    correction: str = ""
-    error_type: str = ""
-    explanation: str = ""
-
-
-class LexiChatResponse(BaseModel):
-    """Structured response from Lexi."""
-    success: bool = True
-    session_id: str
-    message_id: str
-    lexi_response: str
-    audio_base64: Optional[str] = None
-    corrections: List[LexiCorrection] = []
-    linked_concepts: List[str] = []
-    vietnamese_hint: Optional[str] = None
-    scores: Optional[Dict[str, Any]] = None
-    story_context: Optional[str] = None
-    metadata: Dict[str, Any] = {}
-
-
-class LexiSessionResponse(BaseModel):
-    """Response for session creation."""
-    success: bool = True
-    session_id: str
-    created_at: str
-    persona: str = "lexi"
-
-
-class LexiSessionRequest(BaseModel):
-    """Request to create a Lexi session."""
-    user_id: str = Field(default="demo_user", description="User identifier")
-
-
-class LexiSessionRenameRequest(BaseModel):
-    title: str = Field(..., min_length=1, max_length=120)
-
-
-class LexiSessionSummary(BaseModel):
-    session_id: str
-    user_id: str
-    title: str
-    created_at: str
-    updated_at: str
-    message_count: int = 0
-
-
-class LexiSessionListResponse(BaseModel):
-    success: bool = True
-    sessions: List[LexiSessionSummary] = []
-
-
-# ─── Pipeline result ─────────────────────────────────────────────────────────
-
-@dataclass
-class _PipelineResult:
-    lexi_response: str
-    user_text: str
-    message_id: str
-    session_id: str
-    corrections: List["LexiCorrection"] = field(default_factory=list)
-    linked_concepts: List[str] = field(default_factory=list)
-    vietnamese_hint: Optional[str] = None
-    scores: Optional[Dict[str, Any]] = None
-    model_used: str = "trace-cag"
-    story_ctx: Optional[str] = None
-    audio_b64: Optional[str] = None
-    metadata: Dict[str, Any] = field(default_factory=dict)
-
-
-async def _run_lexi_pipeline(
-    request: "LexiChatRequest",
-    session_id: str,
-    history: List[Dict[str, Any]],
-    db: AsyncIOMotorDatabase,
-    quota: Any,
-    start_time: float,
-    skip_tts: bool = False,
-) -> _PipelineResult:
-    """Execute the full Lexi pipeline (STT → TraceCAG → TTS → persist) and return results.
-
-    Extracted so both the regular /chat and the streaming /stream endpoints
-    can share the same logic without duplication.
-    """
-    metadata: Dict[str, Any] = {"pipeline_steps": ["session_ready"]}
-
-    # ── STT ──
-    user_text = request.message
-    if request.input_type == "voice" and request.audio_base64:
-        transcript = await _transcribe_audio(request.audio_base64)
-        if transcript:
-            user_text = transcript
-            metadata["pipeline_steps"].append("stt_complete")
-            metadata["stt_transcript"] = transcript
-        else:
-            metadata["pipeline_steps"].append("stt_failed")
-
-    # ── TraceCAG pipeline ──
-    lexi_response = ""
-    corrections: List[LexiCorrection] = []
-    linked_concepts: List[str] = []
-    vietnamese_hint: Optional[str] = None
-    scores: Optional[Dict[str, Any]] = None
-    model_used = "trace-cag"
-
-    try:
-        from api.services.orchestrator import get_orchestrator
-
-        orchestrator = await get_orchestrator()
-        graph_result = await orchestrator.process(
-            user_input=user_text,
-            session_id=session_id,
-            user_id=request.user_id,
-            learner_profile={"level": request.learner_level},
-            conversation_history=history,
-        )
-        lexi_response = graph_result.get("tutor_response", "")
-        for c in graph_result.get("corrections", []):
-            corrections.append(LexiCorrection(
-                error_span=c.get("error", ""),
-                correction=c.get("correction", ""),
-                error_type=c.get("type", ""),
-                explanation=c.get("explanation", ""),
-            ))
-        linked_concepts = graph_result.get("linked_concepts", [])
-        vietnamese_hint = graph_result.get("vietnamese_hint")
-        scores = graph_result.get("scores")
-        metadata["pipeline_steps"].append("trace-cag_complete")
-        metadata["trace-cag_metadata"] = graph_result.get("metadata", {})
-        model_used = ", ".join(graph_result.get("metadata", {}).get("models_used", ["trace-cag"]))
-
-    except Exception as e:
-        logger.error("TraceCAG hard failure in Lexi pipeline (primary): %s", e)
-        metadata["pipeline_steps"].append("trace-cag_failed_primary")
-        try:
-            from api.services.orchestrator import get_orchestrator
-
-            orchestrator = await get_orchestrator()
-            retry_result = await orchestrator.process(
-                user_input=user_text,
-                session_id=session_id,
-                user_id=request.user_id,
-                learner_profile={"level": request.learner_level},
-                conversation_history=[],
-                cache_policy="off",
-                retrieval_policy="rapid",
-                diagnosis_policy="rules",
-                generation_policy="auto",
-            )
-            lexi_response = str(retry_result.get("tutor_response") or "").strip()
-            if not lexi_response:
-                raise RuntimeError("TraceCAG degraded retry returned empty tutor_response")
-            retry_meta = retry_result.get("metadata", {}) or {}
-            metadata["pipeline_steps"].append("trace-cag_retry_complete")
-            metadata["trace-cag_metadata"] = {
-                **retry_meta,
-                "fallback_used": True,
-                "retry_mode": "trace-cag_degraded",
-                "primary_error": str(e),
-            }
-            model_used = ", ".join(retry_meta.get("models_used", ["trace-cag_retry"]))
-        except Exception as retry_err:
-            logger.error("TraceCAG hard failure in Lexi pipeline (degraded retry): %s", retry_err)
-            metadata["pipeline_steps"].append("trace-cag_failed_hard")
-            metadata["trace-cag_metadata"] = {
-                "fallback_used": True,
-                "primary_error": str(e),
-                "retry_error": str(retry_err),
-            }
-            lexi_response = SAFE_FIXED_RESPONSE
-            model_used = "trace-cag_safe_response"
-
-    # ── Guards ──
-    story_ctx = request.story_context
-    if not story_ctx:
-        _pre_sess = await _store.get_session(session_id)
-        if _pre_sess:
-            story_ctx = _pre_sess.get("story_context")
-
-    if not lexi_response:
-        lexi_response = SAFE_FIXED_RESPONSE
-        model_used = "trace-cag_safe_response"
-        metadata["pipeline_steps"].append("trace-cag_empty_response_guard")
-
-    lexi_response = _sanitize_lexi_response(lexi_response)
-    metadata["model_used"] = model_used
-
-    # ── TTS ──
-    audio_b64: Optional[str] = None
-    if request.enable_tts and not skip_tts:
-        tts_timeout_s = _env_float("LEXI_TTS_TIMEOUT_SECONDS", 8.0, minimum=0.5)
-        try:
-            audio_b64 = await asyncio.wait_for(
-                _synthesize_tts(lexi_response),
-                timeout=tts_timeout_s,
-            )
-            metadata["pipeline_steps"].append("tts_complete" if audio_b64 else "tts_skipped")
-        except asyncio.TimeoutError:
-            logger.warning("Lexi TTS timed out after %.1fs", tts_timeout_s)
-            metadata["pipeline_steps"].append("tts_timeout")
-
-    # ── Persist messages ──
-    message_id = str(uuid.uuid4())
-    timestamp = datetime.now(timezone.utc).isoformat()
-    user_message = {
-        "id": str(uuid.uuid4()),
-        "role": "user",
-        "content": user_text,
-        "timestamp": timestamp,
-    }
-    assistant_message = {
-        "id": message_id,
-        "role": "assistant",
-        "content": lexi_response,
-        "timestamp": timestamp,
-    }
-
-    # Fire all independent writes concurrently: cache append + MongoDB writes.
-    await asyncio.gather(
-        _append_lexi_messages(session_id, [user_message, assistant_message]),
-        db["lexi_messages"].insert_many([
-            {
-                **user_message,
-                "session_id": session_id,
-                "user_id": request.user_id,
-            },
-            {
-                **assistant_message,
-                "session_id": session_id,
-                "user_id": request.user_id,
-            },
-        ]),
-        db["lexi_sessions"].update_one(
-            {"session_id": session_id},
-            {
-                "$set": {
-                    "updated_at": timestamp,
-                    "user_id": request.user_id,
-                },
-                "$inc": {"message_count": 2},
-                "$setOnInsert": {
-                    "created_at": timestamp,
-                    "title": "Lexi Chat",
-                    "persona": "lexi",
-                },
-            },
-            upsert=True,
-        ),
-    )
-
-    # Read session (needed for message_count), then fire session update + conv cache concurrently
-    cached_session = await _store.get_session(session_id) or {}
-    if not story_ctx:
-        story_ctx = cached_session.get("story_context")
-    cached_count = int(cached_session.get("message_count") or 0)
-
-    async def _write_conv_cache():
-        try:
-            from api.core.redis_client import ConversationCache, RedisClient
-            _redis_inst = await RedisClient.get_instance()
-            _conv_cache = ConversationCache(_redis_inst)
-            await _conv_cache.add_turn(
-                session_id=session_id,
-                user_message=user_text,
-                ai_response=lexi_response,
-                metadata={
-                    "model": model_used,
-                    "scores": scores,
-                    "latency_ms": int((time.time() - start_time) * 1000),
-                },
-            )
-        except Exception as _cc_err:
-            logger.debug(f"ConversationCache write skipped: {_cc_err}")
-
-    await asyncio.gather(
-        _store.set_session(session_id, {
-            "session_id": session_id,
-            "user_id": request.user_id,
-            "created_at": cached_session.get("created_at", timestamp),
-            "updated_at": timestamp,
-            "title": cached_session.get("title", "Lexi Chat"),
-            "message_count": cached_count + 2,
-            "persona": cached_session.get("persona", "lexi"),
-            "story_context": story_ctx,
-        }),
-        _write_conv_cache(),
-    )
-
-    total_ms = int((time.time() - start_time) * 1000)
-    metadata["latency_ms"] = total_ms
-    metadata["quota"] = {
-        "rpm_used": quota.rpm_used,
-        "rpm_limit": quota.rpm_limit,
-        "rpd_used": quota.rpd_used,
-        "rpd_limit": quota.rpd_limit,
-        "tpm_used": quota.tpm_used,
-        "tpm_limit": quota.tpm_limit,
-        "tpd_used": quota.tpd_used,
-        "tpd_limit": quota.tpd_limit,
-    }
-    logger.info(
-        f"Lexi pipeline complete — {total_ms}ms, model: {model_used}, "
-        f"steps: {metadata['pipeline_steps']}"
-    )
-
-    return _PipelineResult(
-        lexi_response=lexi_response,
-        user_text=user_text,
-        message_id=message_id,
-        session_id=session_id,
-        corrections=corrections,
-        linked_concepts=linked_concepts,
-        vietnamese_hint=vietnamese_hint,
-        scores=scores,
-        model_used=model_used,
-        story_ctx=story_ctx,
-        audio_b64=audio_b64,
-        metadata=metadata,
-    )
-
-
 # ─── Routes ──────────────────────────────────────────────────────────────────
 @router.post("/sessions", response_model=LexiSessionResponse)
 async def create_lexi_session(
@@ -611,8 +77,8 @@ async def create_lexi_session(
 
     session_id = str(uuid.uuid4())
     now = datetime.now(timezone.utc).isoformat()
-    
-    await _store.set_session(session_id, {
+
+    await svc.lexi_store.set_session(session_id, {
         "session_id": session_id,
         "user_id": request.user_id,
         "created_at": now,
@@ -622,7 +88,7 @@ async def create_lexi_session(
         "persona": "lexi",
         "story_context": None,
     })
-    await _store.init_messages(session_id)
+    await svc.lexi_store.init_messages(session_id)
 
     await db["lexi_sessions"].update_one(
         {"session_id": session_id},
@@ -639,7 +105,7 @@ async def create_lexi_session(
         },
         upsert=True,
     )
-    
+
     logger.info(f" Lexi session created: {session_id[:8]}... for user: {request.user_id}")
     return LexiSessionResponse(session_id=session_id, created_at=now)
 
@@ -648,7 +114,7 @@ async def create_lexi_session(
 async def lexi_chat(
     request_context: Request,
     request: LexiChatRequest,
-    x_idempotency_key: Optional[str] = Header(
+    x_idempotency_key: str | None = Header(
         default=None,
         alias="X-Idempotency-Key",
     ),
@@ -681,20 +147,20 @@ async def lexi_chat(
     # ── 1. Session management ──
     if request.session_id:
         session_id = request.session_id
-        history = await _prepare_existing_lexi_session(session_id, current_user, db)
+        history = await svc.prepare_existing_lexi_session(session_id, current_user, db)
     else:
         session_id = str(uuid.uuid4())
         history = []
-        await _create_lexi_session_for_user(
+        await svc.create_lexi_session_for_user(
             session_id=session_id,
             user_id=request.user_id,
             story_context=request.story_context,
             db=db,
         )
 
-    request_hash = _idempotency_request_hash(request)
+    request_hash = svc.idempotency_request_hash(request)
     if x_idempotency_key:
-        cached_response = await _idempotency_store.get(
+        cached_response = await svc.lexi_idempotency_store.get(
             user_id=request.user_id,
             session_id=session_id,
             idempotency_key=x_idempotency_key,
@@ -704,7 +170,7 @@ async def lexi_chat(
             return LexiChatResponse(**cached_response)
 
     # ── 2–6. Execute shared pipeline (STT → TraceCAG → TTS → persist) ──
-    result = await _run_lexi_pipeline(
+    result = await svc.run_lexi_pipeline(
         request=request,
         session_id=session_id,
         history=history,
@@ -746,7 +212,7 @@ async def lexi_chat(
     )
 
     if x_idempotency_key:
-        await _idempotency_store.set(
+        await svc.lexi_idempotency_store.set(
             user_id=request.user_id,
             session_id=session_id,
             idempotency_key=x_idempotency_key,
@@ -783,7 +249,7 @@ async def lexi_stream_chat(
     auth_user_id = enforce_user_scope(current_user, request.user_id)
     request = request.model_copy(update={"user_id": auth_user_id})
 
-    quota_timeout_s = _env_float("LEXI_STREAM_QUOTA_TIMEOUT_SECONDS", 5.0, minimum=0.5)
+    quota_timeout_s = svc.env_float("LEXI_STREAM_QUOTA_TIMEOUT_SECONDS", 5.0, minimum=0.5)
     try:
         quota = await asyncio.wait_for(
             enforce_user_quota(
@@ -808,16 +274,16 @@ async def lexi_stream_chat(
         ) from exc
 
     session_id = request.session_id or str(uuid.uuid4())
-    prechecked_history: Optional[List[Dict[str, Any]]] = None
+    prechecked_history: list[Dict[str, Any]] | None = None
     if request.session_id:
-        session_timeout_s = _env_float(
+        session_timeout_s = svc.env_float(
             "LEXI_STREAM_SESSION_TIMEOUT_SECONDS",
             15.0,
-            minimum=_HEARTBEAT_INTERVAL_S,
+            minimum=svc.HEARTBEAT_INTERVAL_S,
         )
         try:
             prechecked_history = await asyncio.wait_for(
-                _prepare_existing_lexi_session(session_id, current_user, db),
+                svc.prepare_existing_lexi_session(session_id, current_user, db),
                 timeout=session_timeout_s,
             )
         except asyncio.TimeoutError as exc:
@@ -830,317 +296,17 @@ async def lexi_stream_chat(
                 detail="Chat session service is temporarily unavailable",
             ) from exc
 
-    async def _sse_generator() -> AsyncGenerator[str, None]:
-        from api.services.orchestrator import get_orchestrator
-        from api.services.trace_cag.nodes_v2 import build_generation_prompt, stream_llm_tokens
-        from api.services.trace_cag.evaluation_agent import EvaluationAgent
-
-        user_text = request.message
-
-        # 1. Open the SSE response before touching Redis/Mongo. This prevents a
-        # degraded session store from holding the HTTP response until the edge
-        # proxy returns a 504.
-        yield "event: thinking\ndata: {}\n\n"
-
-        # 2. Session management. Keep sending data events while Redis/Mongo is
-        # slow so Cloudflare and nginx do not treat the stream as idle.
-        if prechecked_history is not None:
-            history = prechecked_history
-        else:
-            async def _prepare_session() -> List[Dict[str, Any]]:
-                await _create_lexi_session_for_user(
-                    session_id=session_id,
-                    user_id=request.user_id,
-                    story_context=request.story_context,
-                    db=db,
-                )
-                return []
-
-            session_task = asyncio.create_task(_prepare_session())
-            loop = asyncio.get_running_loop()
-            session_timeout_s = _env_float(
-                "LEXI_STREAM_SESSION_TIMEOUT_SECONDS",
-                15.0,
-                minimum=_HEARTBEAT_INTERVAL_S,
-            )
-            session_deadline = loop.time() + session_timeout_s
-            while not session_task.done():
-                if loop.time() >= session_deadline:
-                    session_task.cancel()
-                    with suppress(asyncio.CancelledError):
-                        await session_task
-                    logger.error(
-                        "Lexi /stream session preparation timed out after %.1fs",
-                        session_timeout_s,
-                    )
-                    yield (
-                        f"event: error\ndata: "
-                        f"{json.dumps({'error': 'Chat session service is temporarily unavailable.'})}\n\n"
-                    )
-                    return
-                try:
-                    await asyncio.wait_for(
-                        asyncio.shield(session_task),
-                        timeout=_HEARTBEAT_INTERVAL_S,
-                    )
-                except asyncio.TimeoutError:
-                    yield "event: heartbeat\ndata: {}\n\n"
-                except Exception:
-                    break
-
-            try:
-                history = await session_task
-            except Exception as exc:
-                logger.error("Lexi /stream session preparation error: %s", exc)
-                yield (
-                    f"event: error\ndata: "
-                    f"{json.dumps({'error': 'Chat session service is temporarily unavailable.'})}\n\n"
-                )
-                return
-
-        # 3. Context preparation — KG + diagnose + retrieve, NO LLM generation.
-        #    Heartbeat pings keep the SSE connection alive while this runs.
-        #    get_orchestrator() may block on cold start (model loading); run it as
-        #    a task so we can keep pinging while it initialises.
-        try:
-            orch_task = asyncio.create_task(get_orchestrator())
-            loop = asyncio.get_running_loop()
-            orch_deadline = loop.time() + 45.0  # Reduced from 60s: total must fit within Cloudflare's 100s proxy timeout
-            while not orch_task.done():
-                if loop.time() >= orch_deadline:
-                    orch_task.cancel()
-                    yield (
-                        f"event: error\ndata: "
-                        f"{json.dumps({'error': 'Service is starting up. Please try again.'})}\n\n"
-                    )
-                    return
-                try:
-                    await asyncio.wait_for(asyncio.shield(orch_task), timeout=_HEARTBEAT_INTERVAL_S)
-                except asyncio.TimeoutError:
-                    # Use proper SSE data event (not comment) — Cloudflare flushes data events
-                    # immediately but may buffer SSE comment lines (`: ping`).
-                    yield "event: heartbeat\ndata: {}\n\n"
-                except Exception:
-                    break
-            orchestrator = await orch_task
-            ctx_task = asyncio.create_task(
-                orchestrator.pipeline.analyze_for_streaming(
-                    user_input=user_text,
-                    session_id=session_id,
-                    user_id=request.user_id,
-                    learner_profile={"level": request.learner_level},
-                    conversation_history=history,
-                )
-            )
-
-            loop = asyncio.get_running_loop()
-            ctx_deadline = loop.time() + 15.0  # Reduced from 25s: orch(45) + ctx(15) + LLM < 90s
-            while not ctx_task.done():
-                if loop.time() >= ctx_deadline:
-                    ctx_task.cancel()
-                    logger.error("Lexi /stream context prep timed out")
-                    yield (
-                        f"event: error\ndata: "
-                        f"{json.dumps({'error': 'Response timed out. Please try again.'})}\n\n"
-                    )
-                    return
-                try:
-                    await asyncio.wait_for(
-                        asyncio.shield(ctx_task), timeout=_HEARTBEAT_INTERVAL_S
-                    )
-                except asyncio.TimeoutError:
-                    # Use proper SSE data event — Cloudflare flushes data events immediately
-                    yield "event: heartbeat\ndata: {}\n\n"
-                except Exception:
-                    break
-
-            raw_state = await ctx_task
-
-        except Exception as exc:
-            logger.error("Lexi /stream context prep error: %s", exc)
-            yield (
-                f"event: error\ndata: "
-                f"{json.dumps({'error': 'Pipeline failed. Please try again.'})}\n\n"
-            )
-            return
-
-        # Extract corrections / concepts / scores from pipeline state
-        diag_errors = list(raw_state.get("diagnosis_errors") or [])
-        corrections = [
-            LexiCorrection(
-                error_span=str(e.get("span") or ""),
-                correction=str(e.get("correction") or ""),
-                error_type=str(e.get("type") or ""),
-                explanation=str(e.get("explanation") or ""),
-            )
-            for e in diag_errors
-        ]
-        linked_concepts = list(raw_state.get("kg_seed_concepts") or [])
-        vietnamese_hint = raw_state.get("vietnamese_hint")
-        grammar_score = float(raw_state.get("grammar_score") or 0.8)
-        fluency_score = float(raw_state.get("fluency_score") or 0.8)
-        vocab_level = str(raw_state.get("vocabulary_level") or "B1")
-
-        lexi_response = ""
-        model_used = "stream_llm"
-        cache_hit = bool(raw_state.get("cache_hit")) and bool(raw_state.get("tutor_response"))
-
-        # 3. Token streaming
-        if cache_hit:
-            # Cache hit: deliver words quickly — no LLM round-trip needed.
-            lexi_response = _sanitize_lexi_response(str(raw_state["tutor_response"]))
-            model_used = f"cached_{raw_state.get('cache_layer', 'L0')}"
-            for word in lexi_response.split(" "):
-                yield f"event: chunk\ndata: {json.dumps({'text': word + ' '})}\n\n"
-                await asyncio.sleep(0.012)
-        else:
-            # Cache miss: stream real LLM tokens as they arrive.
-            try:
-                system_prompt, llm_messages = build_generation_prompt(raw_state)
-                tokens: list[str] = []
-                async for token in stream_llm_tokens(
-                    system_prompt=system_prompt,
-                    messages=llm_messages,
-                    user_input=user_text,
-                ):
-                    tokens.append(token)
-                    yield f"event: chunk\ndata: {json.dumps({'text': token})}\n\n"
-                lexi_response = _sanitize_lexi_response("".join(tokens))
-            except Exception as gen_err:
-                logger.error("Lexi /stream LLM generation error: %s", gen_err)
-
-            if not lexi_response:
-                lexi_response = SAFE_FIXED_RESPONSE
-                model_used = "trace-cag_safe_response"
-            else:
-                model_used = f"groq/{os.getenv('GROQ_MODEL', 'qwen/qwen3-32b')}" \
-                    if os.getenv("GROQ_API_KEY") else "gemini-2.0-flash"
-
-        # 4. TTS synthesis — after all chunks so TTFB is unaffected
-        audio_b64: Optional[str] = None
-        if request.enable_tts:
-            try:
-                audio_b64 = await asyncio.wait_for(
-                    _synthesize_tts(lexi_response), timeout=8.0
-                )
-            except Exception as tts_err:
-                logger.warning("Lexi stream TTS failed: %s", tts_err)
-
-        # 5. Persist messages (parallelised)
-        message_id = str(uuid.uuid4())
-        timestamp = datetime.now(timezone.utc).isoformat()
-        user_message = {
-            "id": str(uuid.uuid4()),
-            "role": "user",
-            "content": user_text,
-            "timestamp": timestamp,
-        }
-        assistant_message = {
-            "id": message_id,
-            "role": "assistant",
-            "content": lexi_response,
-            "timestamp": timestamp,
-        }
-
-        async def _stream_persist():
-            await asyncio.gather(
-                _append_lexi_messages(session_id, [user_message, assistant_message]),
-                db["lexi_messages"].insert_many([
-                    {**user_message, "session_id": session_id, "user_id": request.user_id},
-                    {**assistant_message, "session_id": session_id, "user_id": request.user_id},
-                ]),
-                db["lexi_sessions"].update_one(
-                    {"session_id": session_id},
-                    {
-                        "$set": {"updated_at": timestamp, "user_id": request.user_id},
-                        "$inc": {"message_count": 2},
-                        "$setOnInsert": {
-                            "created_at": timestamp,
-                            "title": "Lexi Chat",
-                            "persona": "lexi",
-                        },
-                    },
-                    upsert=True,
-                ),
-            )
-            cached_sess = await _store.get_session(session_id) or {}
-            cached_count = int(cached_sess.get("message_count") or 0)
-            await _store.set_session(session_id, {
-                "session_id": session_id,
-                "user_id": request.user_id,
-                "created_at": cached_sess.get("created_at", timestamp),
-                "updated_at": timestamp,
-                "title": cached_sess.get("title", "Lexi Chat"),
-                "message_count": cached_count + 2,
-                "persona": cached_sess.get("persona", "lexi"),
-                "story_context": request.story_context,
-            })
-
-        try:
-            await asyncio.wait_for(_stream_persist(), timeout=5.0)
-        except Exception as persist_err:
-            logger.warning("Lexi stream persist error: %s", persist_err)
-
-        # 6. Done event
-        overall_score = EvaluationAgent.compute_overall_score(
-            grammar_score, fluency_score, vocab_level
-        )
-        scores = {
-            "fluency": fluency_score,
-            "grammar": grammar_score,
-            "overall": overall_score,
-            "vocabulary_level": vocab_level,
-        }
-        total_ms = int((time.time() - start_time) * 1000)
-        done_payload = json.dumps({
-            "message_id": message_id,
-            "session_id": session_id,
-            "lexi_response": lexi_response,
-            "corrections": [
-                {
-                    "error_span": c.error_span,
-                    "correction": c.correction,
-                    "error_type": c.error_type,
-                    "explanation": c.explanation,
-                }
-                for c in corrections
-            ],
-            "linked_concepts": linked_concepts,
-            "vietnamese_hint": vietnamese_hint,
-            "scores": scores,
-            "story_context": request.story_context,
-            "audio_base64": audio_b64,
-            "metadata": {
-                "latency_ms": total_ms,
-                "model_used": model_used,
-                "cache_hit": cache_hit,
-                "quota": {
-                    "rpm_used": quota.rpm_used,
-                    "rpm_limit": quota.rpm_limit,
-                    "rpd_used": quota.rpd_used,
-                    "rpd_limit": quota.rpd_limit,
-                },
-            },
-        })
-        yield f"event: done\ndata: {done_payload}\n\n"
-
-        logger.info(
-            "Lexi /stream complete — %dms, model: %s, cache_hit: %s",
-            total_ms, model_used, cache_hit,
-        )
-        await emit_ai_audit_event({
-            "request_id": request_id,
-            "user_id": current_user.user_id,
-            "endpoint": "lexi.stream",
-            "status": "success",
-            "session_id": session_id,
-            "model_used": model_used,
-            "latency_ms": total_ms,
-            "quota": {"rpm_used": quota.rpm_used, "rpm_limit": quota.rpm_limit},
-        })
-
     return StreamingResponse(
-        _sse_generator(),
+        svc.stream_lexi_chat(
+            request=request,
+            session_id=session_id,
+            prechecked_history=prechecked_history,
+            quota=quota,
+            start_time=start_time,
+            request_id=request_id,
+            current_user=current_user,
+            db=db,
+        ),
         media_type="text/event-stream",
         headers={
             "Cache-Control": "no-cache",
@@ -1176,17 +342,17 @@ async def get_lexi_messages(
 
     session_doc = None
     try:
-        session_doc = await _ensure_session_owner(session_id, current_user, db)
-        cached_session = await _store.get_session(session_id)
+        session_doc = await svc.ensure_session_owner(session_id, current_user, db)
+        cached_session = await svc.lexi_store.get_session(session_id)
     except HTTPException as e:
-        cached_session = await _store.get_session(session_id)
+        cached_session = await svc.lexi_store.get_session(session_id)
         if e.status_code == 404 and cached_session:
             owner_user_id = str(cached_session.get("user_id") or "")
             if owner_user_id and hasattr(current_user, "user_id") and owner_user_id != current_user.user_id:
                 raise HTTPException(status_code=403, detail="Forbidden: session ownership mismatch")
         else:
             raise
-    cached_messages = await _store.get_messages(session_id) if cached_session else []
+    cached_messages = await svc.lexi_store.get_messages(session_id) if cached_session else []
 
     expected_count = int((session_doc or {}).get("message_count") or 0)
     cache_is_complete = cached_session is not None and (
@@ -1222,7 +388,7 @@ async def get_lexi_messages(
     ]
 
     # Rehydrate cache for faster next reads.
-    await _store.set_session(session_id, {
+    await svc.lexi_store.set_session(session_id, {
         "session_id": session_doc.get("session_id"),
         "user_id": session_doc.get("user_id", "demo_user"),
         "created_at": session_doc.get("created_at", datetime.now(timezone.utc).isoformat()),
@@ -1232,9 +398,9 @@ async def get_lexi_messages(
         "persona": session_doc.get("persona", "lexi"),
         "story_context": session_doc.get("story_context"),
     })
-    await _store.delete_messages(session_id)
+    await svc.lexi_store.delete_messages(session_id)
     for item in payload:
-        await _store.append_message(session_id, item)
+        await svc.lexi_store.append_message(session_id, item)
 
     return {
         "success": True,
@@ -1251,7 +417,7 @@ async def get_lexi_messages_paged(
     db: AsyncIOMotorDatabase = Depends(get_database),
     current_user: AuthenticatedUser = Depends(get_current_user),
 ) -> Dict[str, Any]:
-    await _ensure_session_owner(session_id, current_user, db)
+    await svc.ensure_session_owner(session_id, current_user, db)
 
     if limit < 1:
         raise HTTPException(status_code=400, detail="limit must be >= 1")
@@ -1311,7 +477,7 @@ async def get_lexi_messages_metadata(
     db: AsyncIOMotorDatabase = Depends(get_database),
     current_user: AuthenticatedUser = Depends(get_current_user),
 ) -> Dict[str, Any]:
-    await _ensure_session_owner(session_id, current_user, db)
+    await svc.ensure_session_owner(session_id, current_user, db)
 
     base_query: Dict[str, Any] = {"session_id": session_id}
     total_count = await db["lexi_messages"].count_documents(base_query)
@@ -1414,7 +580,7 @@ async def rename_lexi_session(
     db: AsyncIOMotorDatabase = Depends(get_database),
     current_user: AuthenticatedUser = Depends(get_current_user),
 ) -> Dict[str, Any]:
-    await _ensure_session_owner(session_id, current_user, db)
+    await svc.ensure_session_owner(session_id, current_user, db)
 
     title = request.title.strip()
     if not title:
@@ -1428,11 +594,11 @@ async def rename_lexi_session(
     if result.matched_count == 0:
         raise HTTPException(status_code=404, detail="Session not found")
 
-    sess = await _store.get_session(session_id)
+    sess = await svc.lexi_store.get_session(session_id)
     if sess:
         sess["title"] = title
         sess["updated_at"] = now
-        await _store.set_session(session_id, sess)
+        await svc.lexi_store.set_session(session_id, sess)
 
     return {"success": True, "session_id": session_id, "title": title}
 
@@ -1443,12 +609,12 @@ async def delete_lexi_session(
     db: AsyncIOMotorDatabase = Depends(get_database),
     current_user: AuthenticatedUser = Depends(get_current_user),
 ) -> Dict[str, Any]:
-    await _ensure_session_owner(session_id, current_user, db)
+    await svc.ensure_session_owner(session_id, current_user, db)
 
     await db["lexi_sessions"].delete_one({"session_id": session_id})
     await db["lexi_messages"].delete_many({"session_id": session_id})
-    await _store.delete_session(session_id)
-    await _store.delete_messages(session_id)
+    await svc.lexi_store.delete_session(session_id)
+    await svc.lexi_store.delete_messages(session_id)
     return {"success": True, "session_id": session_id}
 
 
diff --git a/ai-service/api/services/embedding_service_v3.py b/ai-service/api/services/embedding_service_v3.py
index 1891c0be..4f5f5a36 100644
--- a/ai-service/api/services/embedding_service_v3.py
+++ b/ai-service/api/services/embedding_service_v3.py
@@ -15,6 +15,7 @@
 import numpy as np
 
 from api.core.config import settings
+from api.services.gemini_compat import import_generativeai
 
 logger = logging.getLogger(__name__)
 
@@ -25,7 +26,9 @@ def __init__(self) -> None:
         self._fallback_mode = False
         self._fallback_reason: str | None = None
         self._fallback_dim = 384
-        self._model_name = getattr(settings, "EMBEDDING_MODEL", "sentence-transformers/all-MiniLM-L6-v2")
+        self._model_name = getattr(
+            settings, "EMBEDDING_MODEL", "sentence-transformers/all-MiniLM-L6-v2"
+        )
         self._device = getattr(settings, "EMBEDDING_DEVICE", "cpu")
 
     def _should_force_fallback(self) -> tuple[bool, str | None]:
@@ -51,7 +54,10 @@ def _major_minor(version: str) -> tuple[int, int]:
         np_major, _ = _major_minor(numpy_version)
         torch_major, torch_minor = _major_minor(torch_version)
         if np_major >= 2 and torch_major == 2 and torch_minor < 4:
-            return True, f"incompatible torch/numpy combo detected (torch={torch_version}, numpy={numpy_version})"
+            return (
+                True,
+                f"incompatible torch/numpy combo detected (torch={torch_version}, numpy={numpy_version})",
+            )
 
         return False, None
 
@@ -67,9 +73,13 @@ def _load_model(self) -> Any:
                 )
                 return None
             try:
-                from sentence_transformers import SentenceTransformer  # lazy import: not available on all platforms
+                from sentence_transformers import (
+                    SentenceTransformer,
+                )  # lazy import: not available on all platforms
 
-                logger.info(f"Loading embedding model: {self._model_name} on {self._device}")
+                logger.info(
+                    f"Loading embedding model: {self._model_name} on {self._device}"
+                )
                 self._model = SentenceTransformer(self._model_name, device=self._device)
             except Exception as exc:  # pragma: no cover - environment-dependent
                 self._fallback_mode = True
@@ -85,11 +95,15 @@ def embed_texts(self, texts: List[str]) -> np.ndarray:
             return np.empty((0, self._fallback_dim), dtype=np.float32)
 
         # Attempt Gemini Cloud Embeddings first if configured
-        prefer_cloud = os.getenv("TRACECAG_PREFER_CLOUD_LLM", "true").lower() in {"1", "true", "yes"}
+        prefer_cloud = os.getenv("TRACECAG_PREFER_CLOUD_LLM", "true").lower() in {
+            "1",
+            "true",
+            "yes",
+        }
         gemini_key = os.getenv("GEMINI_API_KEY", "").strip()
         if prefer_cloud and gemini_key:
             try:
-                import google.generativeai as genai
+                genai = import_generativeai()
                 genai.configure(api_key=gemini_key)
 
                 # embed_content takes `content` (singular) per call.
@@ -100,9 +114,15 @@ def embed_texts(self, texts: List[str]) -> np.ndarray:
                         model="models/text-embedding-004",
                         content=text,
                     )
-                    emb = response.get("embedding") if isinstance(response, dict) else getattr(response, "embedding", None)
+                    emb = (
+                        response.get("embedding")
+                        if isinstance(response, dict)
+                        else getattr(response, "embedding", None)
+                    )
                     if not emb or not isinstance(emb, list):
-                        raise ValueError(f"Unexpected Gemini embedding response: {response!r}")
+                        raise ValueError(
+                            f"Unexpected Gemini embedding response: {response!r}"
+                        )
                     rows.append(emb)
 
                 arr = np.array(rows, dtype=np.float32)
@@ -111,7 +131,9 @@ def embed_texts(self, texts: List[str]) -> np.ndarray:
                 logger.info(f"Generated {len(texts)} embeddings via Gemini API")
                 return arr / norms
             except Exception as e:
-                logger.warning(f"Failed to generate embeddings via Gemini API: {e}. Falling back to local model.")
+                logger.warning(
+                    f"Failed to generate embeddings via Gemini API: {e}. Falling back to local model."
+                )
 
         model = self._load_model()
         if model is None:
diff --git a/ai-service/api/services/gemini_compat.py b/ai-service/api/services/gemini_compat.py
new file mode 100644
index 00000000..670136bc
--- /dev/null
+++ b/ai-service/api/services/gemini_compat.py
@@ -0,0 +1,18 @@
+"""Compatibility helpers for the legacy Gemini SDK."""
+
+from __future__ import annotations
+
+import importlib
+import warnings
+from types import ModuleType
+
+
+def import_generativeai() -> ModuleType:
+    """Import google.generativeai without surfacing its package deprecation warning."""
+    with warnings.catch_warnings():
+        warnings.filterwarnings(
+            "ignore",
+            message=r"\s*All support for the `google\.generativeai` package has ended.*",
+            category=FutureWarning,
+        )
+        return importlib.import_module("google.generativeai")
diff --git a/ai-service/api/services/handlers/gemini_handler.py b/ai-service/api/services/handlers/gemini_handler.py
index 373ac114..205829d5 100644
--- a/ai-service/api/services/handlers/gemini_handler.py
+++ b/ai-service/api/services/handlers/gemini_handler.py
@@ -11,12 +11,15 @@
 from dataclasses import dataclass
 import os
 
+from api.services.gemini_compat import import_generativeai
+
 logger = logging.getLogger(__name__)
 
 
 @dataclass
 class GeminiConfig:
     """Configuration for Gemini API."""
+
     api_key: Optional[str] = None
     model: str = "gemini-1.5-flash"  # Fast and efficient
     temperature: float = 0.7
@@ -28,65 +31,65 @@ class GeminiConfig:
 class GeminiHandler:
     """
     Handler for Google Gemini API.
-    
+
     This is a cloud-based fallback for when local models
     are unavailable or for tasks requiring more capability.
     """
-    
+
     def __init__(self, config: Optional[GeminiConfig] = None):
         self.config = config or GeminiConfig()
         self._client = None
         self._loaded = False
         self._lock = asyncio.Lock()
-        
+
     @property
     def is_loaded(self) -> bool:
         return self._loaded
-    
+
     @property
     def memory_usage_mb(self) -> float:
         """Cloud API uses minimal local memory."""
         return 10.0 if self._loaded else 0.0
-    
+
     async def load(self) -> bool:
         """Initialize Gemini client."""
         if self._loaded:
             return True
-            
+
         async with self._lock:
             if self._loaded:
                 return True
-                
+
             try:
                 logger.info("[GeminiHandler] Initializing Gemini client...")
-                
+
                 # Get API key
                 api_key = self.config.api_key or os.environ.get("GEMINI_API_KEY")
-                
+
                 if not api_key:
                     logger.error("[GeminiHandler] No API key found")
                     return False
-                
-                import google.generativeai as genai
-                
+
+                genai = import_generativeai()
+
                 genai.configure(api_key=api_key)
                 self._client = genai.GenerativeModel(self.config.model)
-                
+
                 self._loaded = True
                 logger.info("[GeminiHandler]  Gemini client initialized")
                 return True
-                
+
             except Exception as e:
                 logger.error(f"[GeminiHandler] Failed to initialize: {e}")
                 self._loaded = False
                 return False
-    
+
     async def unload(self) -> None:
         """Cleanup resources."""
         self._client = None
         self._loaded = False
         logger.info("[GeminiHandler] Client unloaded")
-    
+
     async def chat(
         self,
         messages: List[Dict[str, str]],
@@ -96,25 +99,25 @@ async def chat(
     ) -> str:
         """
         Generate chat response.
-        
+
         Args:
             messages: List of {"role": "user/model", "content": "..."}
             system_prompt: System instructions
             temperature: Override config temperature
             max_tokens: Override max output tokens
-            
+
         Returns:
             Generated response text
         """
         if not await self.load():
             raise RuntimeError("Failed to initialize Gemini")
-        
+
         # Build prompt
         parts = []
-        
+
         if system_prompt:
             parts.append(f"System: {system_prompt}\n\n")
-        
+
         for msg in messages:
             role = msg.get("role", "user")
             content = msg.get("content", "")
@@ -122,9 +125,9 @@ async def chat(
                 parts.append(f"User: {content}\n")
             elif role in ("assistant", "model"):
                 parts.append(f"Assistant: {content}\n")
-        
+
         prompt = "".join(parts)
-        
+
         # Generate
         generation_config = {
             "temperature": temperature or self.config.temperature,
@@ -132,7 +135,7 @@ async def chat(
             "top_p": self.config.top_p,
             "top_k": self.config.top_k,
         }
-        
+
         try:
             response = await asyncio.to_thread(
                 self._client.generate_content,
@@ -143,7 +146,7 @@ async def chat(
         except Exception as e:
             logger.error(f"[GeminiHandler] Generation failed: {e}")
             raise
-    
+
     async def analyze_grammar(
         self,
         text: str,
@@ -151,7 +154,7 @@ async def analyze_grammar(
     ) -> Dict[str, Any]:
         """
         Analyze grammar and provide corrections.
-        
+
         Returns similar structure to QwenHandler for compatibility.
         """
         system_prompt = f"""You are an expert {target_language} grammar tutor.
@@ -175,16 +178,17 @@ async def analyze_grammar(
 Be thorough but fair. Score 1.0 means perfect."""
 
         messages = [{"role": "user", "content": f"Analyze this text:\n\n{text}"}]
-        
+
         response = await self.chat(
             messages,
             system_prompt=system_prompt,
             temperature=0.3,
         )
-        
+
         # Parse JSON response
         try:
             import json
+
             # Clean response
             response = response.strip()
             if response.startswith("```"):
@@ -193,7 +197,7 @@ async def analyze_grammar(
                 else:
                     response = response.split("```")[1]
                 response = response.split("```")[0]
-            
+
             result = json.loads(response.strip())
             return result
         except json.JSONDecodeError:
@@ -204,7 +208,7 @@ async def analyze_grammar(
                 "fluency_score": 0.8,
                 "raw_response": response,
             }
-    
+
     async def generate_response(
         self,
         user_input: str,
@@ -231,19 +235,18 @@ async def generate_response(
                 f"- '{e.get('span')}' → '{e.get('correction')}' ({e.get('type')})"
                 for e in errors
             )
-        
-        messages = [{
-            "role": "user",
-            "content": f"{user_input}{context_str}{errors_str}"
-        }]
-        
+
+        messages = [
+            {"role": "user", "content": f"{user_input}{context_str}{errors_str}"}
+        ]
+
         return await self.chat(
             messages,
             system_prompt=system_prompt,
             temperature=0.7,
             max_tokens=400,
         )
-    
+
     async def explain_vietnamese(
         self,
         english_text: str,
@@ -259,23 +262,22 @@ async def explain_vietnamese(
         content = f"Explain in Vietnamese:\n\n{english_text}"
         if errors:
             content += "\n\nErrors to explain:\n" + "\n".join(
-                f"- '{e.get('span')}' → '{e.get('correction')}'"
-                for e in errors
+                f"- '{e.get('span')}' → '{e.get('correction')}'" for e in errors
             )
-        
+
         messages = [{"role": "user", "content": content}]
-        
+
         return await self.chat(
             messages,
             system_prompt=system_prompt,
             temperature=0.7,
             max_tokens=300,
         )
-    
+
     async def invoke(self, params: Dict[str, Any]) -> Dict[str, Any]:
         """
         Unified invoke interface for ModelGateway.
-        
+
         Args:
             params: {
                 "task": "chat" | "grammar" | "response" | "vietnamese",
@@ -283,17 +285,17 @@ async def invoke(self, params: Dict[str, Any]) -> Dict[str, Any]:
                 "messages": [...],
                 ...other params
             }
-            
+
         Returns:
             Task-specific result
         """
         task = params.get("task", "chat")
-        
+
         if task == "grammar":
             return await self.analyze_grammar(
                 text=params.get("text", ""),
             )
-            
+
         elif task == "response":
             return {
                 "response": await self.generate_response(
@@ -303,7 +305,7 @@ async def invoke(self, params: Dict[str, Any]) -> Dict[str, Any]:
                     errors=params.get("errors"),
                 )
             }
-            
+
         elif task == "vietnamese":
             return {
                 "explanation": await self.explain_vietnamese(
@@ -312,12 +314,12 @@ async def invoke(self, params: Dict[str, Any]) -> Dict[str, Any]:
                     learner_level=params.get("level", "B1"),
                 )
             }
-            
+
         else:  # chat
             messages = params.get("messages", [])
             if not messages and params.get("text"):
                 messages = [{"role": "user", "content": params["text"]}]
-            
+
             return {
                 "response": await self.chat(
                     messages=messages,
diff --git a/ai-service/api/services/lexi_chat_service.py b/ai-service/api/services/lexi_chat_service.py
new file mode 100644
index 00000000..0742499e
--- /dev/null
+++ b/ai-service/api/services/lexi_chat_service.py
@@ -0,0 +1,879 @@
+"""
+Lexi chat pipeline service — owns the actual conversation turn orchestration
+(session bootstrapping, STT, TraceCAG, TTS, persistence) so the route module
+only has to parse requests and shape responses.
+
+Extracted from api/routes/lexi_chat.py so /chat and /stream share one
+implementation without the orchestration living in a route handler.
+"""
+
+import asyncio
+import json
+import logging
+import os
+import time
+import uuid
+from contextlib import suppress
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from typing import Any, AsyncGenerator, Dict, List, Optional
+
+from fastapi import HTTPException
+from motor.motor_asyncio import AsyncIOMotorDatabase
+from pydantic import BaseModel, Field
+
+from api.core.auth import AuthenticatedUser
+from api.utils.cursor import to_iso_timestamp
+from api.services.lexi_session_store import LexiSessionStore, get_lexi_store
+from api.services.lexi_idempotency_store import LexiIdempotencyStore, get_lexi_idempotency_store
+from api.services.lexi_pipeline_helpers import (
+    sanitize_lexi_response as _sanitize_lexi_response,
+    synthesize_tts as _synthesize_tts,
+    transcribe_audio as _transcribe_audio,
+)
+
+logger = logging.getLogger(__name__)
+
+lexi_store: LexiSessionStore = get_lexi_store()
+lexi_idempotency_store: LexiIdempotencyStore = get_lexi_idempotency_store()
+
+SAFE_FIXED_RESPONSE = (
+    "Squawk! I'm temporarily unavailable right now. "
+    "Please try again in a moment."
+)
+
+# SSE stream settings
+HEARTBEAT_INTERVAL_S = 2.5  # how often to send a heartbeat to keep proxies alive
+
+
+def env_float(name: str, default: float, minimum: float = 0.0) -> float:
+    raw = os.getenv(name)
+    if raw is None:
+        return default
+    try:
+        return max(minimum, float(raw))
+    except ValueError:
+        return default
+
+
+# ─── Request / Response Models ───────────────────────────────────────────────
+class LexiChatRequest(BaseModel):
+    """Request to chat with Lexi."""
+    user_id: str = Field(default="demo_user", description="User identifier")
+    session_id: Optional[str] = Field(default=None, description="Existing session ID")
+    message: str = Field(..., min_length=1, description="User message text")
+    input_type: str = Field(default="text", description="'text' or 'voice'")
+    audio_base64: Optional[str] = Field(default=None, description="Base64 audio for STT")
+    enable_tts: bool = Field(default=True, description="Generate TTS audio response")
+    learner_level: str = Field(default="B1", description="CEFR level: A1-C2")
+    native_language: str = Field(default="vi", description="ISO 639-1 code, e.g. vi/en/ja")
+    story_context: Optional[str] = Field(default=None, description="Story/adventure context")
+
+
+class LexiCorrection(BaseModel):
+    """A grammar/vocabulary correction."""
+    error_span: str = ""
+    correction: str = ""
+    error_type: str = ""
+    explanation: str = ""
+
+
+class LexiChatResponse(BaseModel):
+    """Structured response from Lexi."""
+    success: bool = True
+    session_id: str
+    message_id: str
+    lexi_response: str
+    audio_base64: Optional[str] = None
+    corrections: List[LexiCorrection] = []
+    linked_concepts: List[str] = []
+    vietnamese_hint: Optional[str] = None
+    scores: Optional[Dict[str, Any]] = None
+    story_context: Optional[str] = None
+    metadata: Dict[str, Any] = {}
+
+
+class LexiSessionResponse(BaseModel):
+    """Response for session creation."""
+    success: bool = True
+    session_id: str
+    created_at: str
+    persona: str = "lexi"
+
+
+class LexiSessionRequest(BaseModel):
+    """Request to create a Lexi session."""
+    user_id: str = Field(default="demo_user", description="User identifier")
+
+
+class LexiSessionRenameRequest(BaseModel):
+    title: str = Field(..., min_length=1, max_length=120)
+
+
+class LexiSessionSummary(BaseModel):
+    session_id: str
+    user_id: str
+    title: str
+    created_at: str
+    updated_at: str
+    message_count: int = 0
+
+
+class LexiSessionListResponse(BaseModel):
+    success: bool = True
+    sessions: List[LexiSessionSummary] = []
+
+
+def idempotency_request_hash(request: "LexiChatRequest") -> str:
+    import hashlib
+
+    payload = {
+        "user_id": request.user_id,
+        "session_id": request.session_id,
+        "message": request.message,
+        "input_type": request.input_type,
+        "audio_base64": request.audio_base64,
+        "enable_tts": request.enable_tts,
+        "learner_level": request.learner_level,
+        "native_language": request.native_language,
+        "story_context": request.story_context,
+    }
+    normalized = json.dumps(payload, sort_keys=True, separators=(",", ":"))
+    return hashlib.sha256(normalized.encode("utf-8")).hexdigest()
+
+
+# ─── Session bootstrapping ───────────────────────────────────────────────────
+async def ensure_session_owner(
+    session_id: str,
+    current_user: AuthenticatedUser,
+    db: AsyncIOMotorDatabase,
+) -> Dict[str, Any]:
+    session_doc = await db["lexi_sessions"].find_one({"session_id": session_id})
+    if not session_doc:
+        raise HTTPException(status_code=404, detail="Session not found")
+
+    owner_user_id = str(session_doc.get("user_id") or "")
+    if owner_user_id and owner_user_id != current_user.user_id:
+        raise HTTPException(status_code=403, detail="Forbidden: session ownership mismatch")
+    return session_doc
+
+
+def assert_cached_session_owner(
+    cached_session: Dict[str, Any] | None,
+    current_user: AuthenticatedUser,
+) -> None:
+    if not cached_session:
+        return
+    owner_user_id = str(cached_session.get("user_id") or "")
+    if owner_user_id and owner_user_id != current_user.user_id:
+        raise HTTPException(status_code=403, detail="Forbidden: session ownership mismatch")
+
+
+async def get_cached_session_with_messages(
+    session_id: str,
+) -> tuple[Dict[str, Any] | None, List[Dict[str, Any]]]:
+    if callable(getattr(type(lexi_store), "get_session_with_messages", None)):
+        return await lexi_store.get_session_with_messages(session_id)
+
+    cached_session, cached_messages = await asyncio.gather(
+        lexi_store.get_session(session_id),
+        lexi_store.get_messages(session_id),
+    )
+    return cached_session, cached_messages
+
+
+async def prepare_existing_lexi_session(
+    session_id: str,
+    current_user: AuthenticatedUser,
+    db: AsyncIOMotorDatabase,
+) -> List[Dict[str, Any]]:
+    cached_session, cached_messages = await get_cached_session_with_messages(session_id)
+    cached_owner = str((cached_session or {}).get("user_id") or "")
+    if cached_session and cached_owner:
+        assert_cached_session_owner(cached_session, current_user)
+        return cached_messages
+
+    try:
+        await ensure_session_owner(session_id, current_user, db)
+    except HTTPException as exc:
+        if exc.status_code != 404:
+            raise
+        assert_cached_session_owner(cached_session, current_user)
+        if not cached_session:
+            raise
+        return cached_messages
+
+    assert_cached_session_owner(cached_session, current_user)
+    if cached_session:
+        return cached_messages
+
+    docs = await (
+        db["lexi_messages"]
+        .find({"session_id": session_id})
+        .sort("timestamp", -1)
+        .limit(10)
+        .to_list(length=10)
+    )
+    docs.reverse()
+    return [
+        {
+            "id": doc.get("id") or doc.get("message_id") or str(doc.get("_id", "")),
+            "role": doc.get("role", "user"),
+            "content": doc.get("content", ""),
+            "timestamp": to_iso_timestamp(doc.get("timestamp")),
+        }
+        for doc in docs
+    ]
+
+
+async def create_lexi_session_for_user(
+    session_id: str,
+    user_id: str,
+    story_context: Optional[str],
+    db: AsyncIOMotorDatabase,
+) -> None:
+    now_iso = datetime.now(timezone.utc).isoformat()
+    await asyncio.gather(
+        lexi_store.set_session(session_id, {
+            "session_id": session_id,
+            "user_id": user_id,
+            "created_at": now_iso,
+            "updated_at": now_iso,
+            "title": "Lexi Chat",
+            "message_count": 0,
+            "persona": "lexi",
+            "story_context": story_context,
+        }),
+        lexi_store.init_messages(session_id),
+        db["lexi_sessions"].update_one(
+            {"session_id": session_id},
+            {
+                "$set": {
+                    "session_id": session_id,
+                    "user_id": user_id,
+                    "title": "Lexi Chat",
+                    "created_at": now_iso,
+                    "updated_at": now_iso,
+                    "message_count": 0,
+                    "persona": "lexi",
+                }
+            },
+            upsert=True,
+        ),
+    )
+
+
+async def append_lexi_messages(
+    session_id: str,
+    messages: List[Dict[str, Any]],
+) -> None:
+    if callable(getattr(type(lexi_store), "append_messages", None)):
+        await lexi_store.append_messages(session_id, messages)
+        return
+
+    await asyncio.gather(
+        *(lexi_store.append_message(session_id, message) for message in messages)
+    )
+
+
+# ─── Pipeline result ─────────────────────────────────────────────────────────
+@dataclass
+class PipelineResult:
+    lexi_response: str
+    user_text: str
+    message_id: str
+    session_id: str
+    corrections: List["LexiCorrection"] = field(default_factory=list)
+    linked_concepts: List[str] = field(default_factory=list)
+    vietnamese_hint: Optional[str] = None
+    scores: Optional[Dict[str, Any]] = None
+    model_used: str = "trace-cag"
+    story_ctx: Optional[str] = None
+    audio_b64: Optional[str] = None
+    metadata: Dict[str, Any] = field(default_factory=dict)
+
+
+async def run_lexi_pipeline(
+    request: "LexiChatRequest",
+    session_id: str,
+    history: List[Dict[str, Any]],
+    db: AsyncIOMotorDatabase,
+    quota: Any,
+    start_time: float,
+    skip_tts: bool = False,
+) -> PipelineResult:
+    """Execute the full Lexi pipeline (STT → TraceCAG → TTS → persist) and return results.
+
+    Shared by both the regular /chat and the streaming /stream endpoints so
+    they don't duplicate this logic.
+    """
+    metadata: Dict[str, Any] = {"pipeline_steps": ["session_ready"]}
+
+    # ── STT ──
+    user_text = request.message
+    if request.input_type == "voice" and request.audio_base64:
+        transcript = await _transcribe_audio(request.audio_base64)
+        if transcript:
+            user_text = transcript
+            metadata["pipeline_steps"].append("stt_complete")
+            metadata["stt_transcript"] = transcript
+        else:
+            metadata["pipeline_steps"].append("stt_failed")
+
+    # ── TraceCAG pipeline ──
+    lexi_response = ""
+    corrections: List[LexiCorrection] = []
+    linked_concepts: List[str] = []
+    vietnamese_hint: Optional[str] = None
+    scores: Optional[Dict[str, Any]] = None
+    model_used = "trace-cag"
+
+    try:
+        from api.services.orchestrator import get_orchestrator
+        from api.utils.languages import iso_to_language_name
+
+        orchestrator = await get_orchestrator()
+        graph_result = await orchestrator.process(
+            user_input=user_text,
+            session_id=session_id,
+            user_id=request.user_id,
+            learner_profile={
+                "level": request.learner_level,
+                "native_language": iso_to_language_name(request.native_language),
+            },
+            conversation_history=history,
+        )
+        lexi_response = graph_result.get("tutor_response", "")
+        for c in graph_result.get("corrections", []):
+            corrections.append(LexiCorrection(
+                error_span=c.get("error", ""),
+                correction=c.get("correction", ""),
+                error_type=c.get("type", ""),
+                explanation=c.get("explanation", ""),
+            ))
+        linked_concepts = graph_result.get("linked_concepts", [])
+        vietnamese_hint = graph_result.get("vietnamese_hint")
+        scores = graph_result.get("scores")
+        metadata["pipeline_steps"].append("trace-cag_complete")
+        metadata["trace-cag_metadata"] = graph_result.get("metadata", {})
+        model_used = ", ".join(graph_result.get("metadata", {}).get("models_used", ["trace-cag"]))
+
+    except Exception as e:
+        logger.error("TraceCAG hard failure in Lexi pipeline (primary): %s", e)
+        metadata["pipeline_steps"].append("trace-cag_failed_primary")
+        try:
+            from api.services.orchestrator import get_orchestrator
+            from api.utils.languages import iso_to_language_name
+
+            orchestrator = await get_orchestrator()
+            retry_result = await orchestrator.process(
+                user_input=user_text,
+                session_id=session_id,
+                user_id=request.user_id,
+                learner_profile={
+                    "level": request.learner_level,
+                    "native_language": iso_to_language_name(request.native_language),
+                },
+                conversation_history=[],
+                cache_policy="off",
+                retrieval_policy="rapid",
+                diagnosis_policy="rules",
+                generation_policy="auto",
+            )
+            lexi_response = str(retry_result.get("tutor_response") or "").strip()
+            if not lexi_response:
+                raise RuntimeError("TraceCAG degraded retry returned empty tutor_response")
+            retry_meta = retry_result.get("metadata", {}) or {}
+            metadata["pipeline_steps"].append("trace-cag_retry_complete")
+            metadata["trace-cag_metadata"] = {
+                **retry_meta,
+                "fallback_used": True,
+                "retry_mode": "trace-cag_degraded",
+                "primary_error": str(e),
+            }
+            model_used = ", ".join(retry_meta.get("models_used", ["trace-cag_retry"]))
+        except Exception as retry_err:
+            logger.error("TraceCAG hard failure in Lexi pipeline (degraded retry): %s", retry_err)
+            metadata["pipeline_steps"].append("trace-cag_failed_hard")
+            metadata["trace-cag_metadata"] = {
+                "fallback_used": True,
+                "primary_error": str(e),
+                "retry_error": str(retry_err),
+            }
+            lexi_response = SAFE_FIXED_RESPONSE
+            model_used = "trace-cag_safe_response"
+
+    # ── Guards ──
+    story_ctx = request.story_context
+    if not story_ctx:
+        _pre_sess = await lexi_store.get_session(session_id)
+        if _pre_sess:
+            story_ctx = _pre_sess.get("story_context")
+
+    if not lexi_response:
+        lexi_response = SAFE_FIXED_RESPONSE
+        model_used = "trace-cag_safe_response"
+        metadata["pipeline_steps"].append("trace-cag_empty_response_guard")
+
+    lexi_response = _sanitize_lexi_response(lexi_response)
+    metadata["model_used"] = model_used
+
+    # ── TTS ──
+    audio_b64: Optional[str] = None
+    if request.enable_tts and not skip_tts:
+        tts_timeout_s = env_float("LEXI_TTS_TIMEOUT_SECONDS", 8.0, minimum=0.5)
+        try:
+            audio_b64 = await asyncio.wait_for(
+                _synthesize_tts(lexi_response),
+                timeout=tts_timeout_s,
+            )
+            metadata["pipeline_steps"].append("tts_complete" if audio_b64 else "tts_skipped")
+        except asyncio.TimeoutError:
+            logger.warning("Lexi TTS timed out after %.1fs", tts_timeout_s)
+            metadata["pipeline_steps"].append("tts_timeout")
+
+    # ── Persist messages ──
+    message_id = str(uuid.uuid4())
+    timestamp = datetime.now(timezone.utc).isoformat()
+    user_message = {
+        "id": str(uuid.uuid4()),
+        "role": "user",
+        "content": user_text,
+        "timestamp": timestamp,
+    }
+    assistant_message = {
+        "id": message_id,
+        "role": "assistant",
+        "content": lexi_response,
+        "timestamp": timestamp,
+    }
+
+    # Fire all independent writes concurrently: cache append + MongoDB writes.
+    await asyncio.gather(
+        append_lexi_messages(session_id, [user_message, assistant_message]),
+        db["lexi_messages"].insert_many([
+            {
+                **user_message,
+                "session_id": session_id,
+                "user_id": request.user_id,
+            },
+            {
+                **assistant_message,
+                "session_id": session_id,
+                "user_id": request.user_id,
+            },
+        ]),
+        db["lexi_sessions"].update_one(
+            {"session_id": session_id},
+            {
+                "$set": {
+                    "updated_at": timestamp,
+                    "user_id": request.user_id,
+                },
+                "$inc": {"message_count": 2},
+                "$setOnInsert": {
+                    "created_at": timestamp,
+                    "title": "Lexi Chat",
+                    "persona": "lexi",
+                },
+            },
+            upsert=True,
+        ),
+    )
+
+    # Read session (needed for message_count), then fire session update + conv cache concurrently
+    cached_session = await lexi_store.get_session(session_id) or {}
+    if not story_ctx:
+        story_ctx = cached_session.get("story_context")
+    cached_count = int(cached_session.get("message_count") or 0)
+
+    async def _write_conv_cache():
+        try:
+            from api.core.redis_client import ConversationCache, RedisClient
+            _redis_inst = await RedisClient.get_instance()
+            _conv_cache = ConversationCache(_redis_inst)
+            await _conv_cache.add_turn(
+                session_id=session_id,
+                user_message=user_text,
+                ai_response=lexi_response,
+                metadata={
+                    "model": model_used,
+                    "scores": scores,
+                    "latency_ms": int((time.time() - start_time) * 1000),
+                },
+            )
+        except Exception as _cc_err:
+            logger.debug(f"ConversationCache write skipped: {_cc_err}")
+
+    await asyncio.gather(
+        lexi_store.set_session(session_id, {
+            "session_id": session_id,
+            "user_id": request.user_id,
+            "created_at": cached_session.get("created_at", timestamp),
+            "updated_at": timestamp,
+            "title": cached_session.get("title", "Lexi Chat"),
+            "message_count": cached_count + 2,
+            "persona": cached_session.get("persona", "lexi"),
+            "story_context": story_ctx,
+        }),
+        _write_conv_cache(),
+    )
+
+    total_ms = int((time.time() - start_time) * 1000)
+    metadata["latency_ms"] = total_ms
+    metadata["quota"] = {
+        "rpm_used": quota.rpm_used,
+        "rpm_limit": quota.rpm_limit,
+        "rpd_used": quota.rpd_used,
+        "rpd_limit": quota.rpd_limit,
+        "tpm_used": quota.tpm_used,
+        "tpm_limit": quota.tpm_limit,
+        "tpd_used": quota.tpd_used,
+        "tpd_limit": quota.tpd_limit,
+    }
+    logger.info(
+        f"Lexi pipeline complete — {total_ms}ms, model: {model_used}, "
+        f"steps: {metadata['pipeline_steps']}"
+    )
+
+    return PipelineResult(
+        lexi_response=lexi_response,
+        user_text=user_text,
+        message_id=message_id,
+        session_id=session_id,
+        corrections=corrections,
+        linked_concepts=linked_concepts,
+        vietnamese_hint=vietnamese_hint,
+        scores=scores,
+        model_used=model_used,
+        story_ctx=story_ctx,
+        audio_b64=audio_b64,
+        metadata=metadata,
+    )
+
+
+async def stream_lexi_chat(
+    request: "LexiChatRequest",
+    session_id: str,
+    prechecked_history: Optional[List[Dict[str, Any]]],
+    quota: Any,
+    start_time: float,
+    request_id: str,
+    current_user: AuthenticatedUser,
+    db: AsyncIOMotorDatabase,
+) -> AsyncGenerator[str, None]:
+    """SSE generator for the streaming Lexi chat pipeline. See lexi_stream_chat
+    route docstring for the event sequence (thinking/heartbeat/chunk/done/error).
+    """
+    from api.core.audit_emitter import emit_ai_audit_event
+    from api.services.orchestrator import get_orchestrator
+    from api.services.trace_cag.nodes_v2 import build_generation_prompt, stream_llm_tokens
+    from api.services.trace_cag.evaluation_agent import EvaluationAgent
+    from api.utils.languages import iso_to_language_name
+
+    user_text = request.message
+
+    # 1. Open the SSE response before touching Redis/Mongo. This prevents a
+    # degraded session store from holding the HTTP response until the edge
+    # proxy returns a 504.
+    yield "event: thinking\ndata: {}\n\n"
+
+    # 2. Session management. Keep sending data events while Redis/Mongo is
+    # slow so Cloudflare and nginx do not treat the stream as idle.
+    if prechecked_history is not None:
+        history = prechecked_history
+    else:
+        async def _prepare_session() -> List[Dict[str, Any]]:
+            await create_lexi_session_for_user(
+                session_id=session_id,
+                user_id=request.user_id,
+                story_context=request.story_context,
+                db=db,
+            )
+            return []
+
+        session_task = asyncio.create_task(_prepare_session())
+        loop = asyncio.get_running_loop()
+        session_timeout_s = env_float(
+            "LEXI_STREAM_SESSION_TIMEOUT_SECONDS",
+            15.0,
+            minimum=HEARTBEAT_INTERVAL_S,
+        )
+        session_deadline = loop.time() + session_timeout_s
+        while not session_task.done():
+            if loop.time() >= session_deadline:
+                session_task.cancel()
+                with suppress(asyncio.CancelledError):
+                    await session_task
+                logger.error(
+                    "Lexi /stream session preparation timed out after %.1fs",
+                    session_timeout_s,
+                )
+                yield (
+                    f"event: error\ndata: "
+                    f"{json.dumps({'error': 'Chat session service is temporarily unavailable.'})}\n\n"
+                )
+                return
+            try:
+                await asyncio.wait_for(
+                    asyncio.shield(session_task),
+                    timeout=HEARTBEAT_INTERVAL_S,
+                )
+            except asyncio.TimeoutError:
+                yield "event: heartbeat\ndata: {}\n\n"
+            except Exception:
+                break
+
+        try:
+            history = await session_task
+        except Exception as exc:
+            logger.error("Lexi /stream session preparation error: %s", exc)
+            yield (
+                f"event: error\ndata: "
+                f"{json.dumps({'error': 'Chat session service is temporarily unavailable.'})}\n\n"
+            )
+            return
+
+    # 3. Context preparation — KG + diagnose + retrieve, NO LLM generation.
+    #    Heartbeat pings keep the SSE connection alive while this runs.
+    #    get_orchestrator() may block on cold start (model loading); run it as
+    #    a task so we can keep pinging while it initialises.
+    try:
+        orch_task = asyncio.create_task(get_orchestrator())
+        loop = asyncio.get_running_loop()
+        orch_deadline = loop.time() + 45.0  # Reduced from 60s: total must fit within Cloudflare's 100s proxy timeout
+        while not orch_task.done():
+            if loop.time() >= orch_deadline:
+                orch_task.cancel()
+                yield (
+                    f"event: error\ndata: "
+                    f"{json.dumps({'error': 'Service is starting up. Please try again.'})}\n\n"
+                )
+                return
+            try:
+                await asyncio.wait_for(asyncio.shield(orch_task), timeout=HEARTBEAT_INTERVAL_S)
+            except asyncio.TimeoutError:
+                # Use proper SSE data event (not comment) — Cloudflare flushes data events
+                # immediately but may buffer SSE comment lines (`: ping`).
+                yield "event: heartbeat\ndata: {}\n\n"
+            except Exception:
+                break
+        orchestrator = await orch_task
+        ctx_task = asyncio.create_task(
+            orchestrator.pipeline.analyze_for_streaming(
+                user_input=user_text,
+                session_id=session_id,
+                user_id=request.user_id,
+                learner_profile={
+                    "level": request.learner_level,
+                    "native_language": iso_to_language_name(request.native_language),
+                },
+                conversation_history=history,
+            )
+        )
+
+        loop = asyncio.get_running_loop()
+        ctx_deadline = loop.time() + 15.0  # Reduced from 25s: orch(45) + ctx(15) + LLM < 90s
+        while not ctx_task.done():
+            if loop.time() >= ctx_deadline:
+                ctx_task.cancel()
+                logger.error("Lexi /stream context prep timed out")
+                yield (
+                    f"event: error\ndata: "
+                    f"{json.dumps({'error': 'Response timed out. Please try again.'})}\n\n"
+                )
+                return
+            try:
+                await asyncio.wait_for(
+                    asyncio.shield(ctx_task), timeout=HEARTBEAT_INTERVAL_S
+                )
+            except asyncio.TimeoutError:
+                # Use proper SSE data event — Cloudflare flushes data events immediately
+                yield "event: heartbeat\ndata: {}\n\n"
+            except Exception:
+                break
+
+        raw_state = await ctx_task
+
+    except Exception as exc:
+        logger.error("Lexi /stream context prep error: %s", exc)
+        yield (
+            f"event: error\ndata: "
+            f"{json.dumps({'error': 'Pipeline failed. Please try again.'})}\n\n"
+        )
+        return
+
+    # Extract corrections / concepts / scores from pipeline state
+    diag_errors = list(raw_state.get("diagnosis_errors") or [])
+    corrections = [
+        LexiCorrection(
+            error_span=str(e.get("span") or ""),
+            correction=str(e.get("correction") or ""),
+            error_type=str(e.get("type") or ""),
+            explanation=str(e.get("explanation") or ""),
+        )
+        for e in diag_errors
+    ]
+    linked_concepts = list(raw_state.get("kg_seed_concepts") or [])
+    vietnamese_hint = raw_state.get("vietnamese_hint")
+    grammar_score = float(raw_state.get("grammar_score") or 0.8)
+    fluency_score = float(raw_state.get("fluency_score") or 0.8)
+    vocab_level = str(raw_state.get("vocabulary_level") or "B1")
+
+    lexi_response = ""
+    model_used = "stream_llm"
+    cache_hit = bool(raw_state.get("cache_hit")) and bool(raw_state.get("tutor_response"))
+
+    # 3. Token streaming
+    if cache_hit:
+        # Cache hit: deliver words quickly — no LLM round-trip needed.
+        lexi_response = _sanitize_lexi_response(str(raw_state["tutor_response"]))
+        model_used = f"cached_{raw_state.get('cache_layer', 'L0')}"
+        for word in lexi_response.split(" "):
+            yield f"event: chunk\ndata: {json.dumps({'text': word + ' '})}\n\n"
+            await asyncio.sleep(0.012)
+    else:
+        # Cache miss: stream real LLM tokens as they arrive.
+        try:
+            system_prompt, llm_messages = build_generation_prompt(raw_state)
+            tokens: list[str] = []
+            async for token in stream_llm_tokens(
+                system_prompt=system_prompt,
+                messages=llm_messages,
+                user_input=user_text,
+            ):
+                tokens.append(token)
+                yield f"event: chunk\ndata: {json.dumps({'text': token})}\n\n"
+            lexi_response = _sanitize_lexi_response("".join(tokens))
+        except Exception as gen_err:
+            logger.error("Lexi /stream LLM generation error: %s", gen_err)
+
+        if not lexi_response:
+            lexi_response = SAFE_FIXED_RESPONSE
+            model_used = "trace-cag_safe_response"
+        else:
+            model_used = f"groq/{os.getenv('GROQ_MODEL', 'qwen/qwen3-32b')}" \
+                if os.getenv("GROQ_API_KEY") else "gemini-2.0-flash"
+
+    # 4. TTS synthesis — after all chunks so TTFB is unaffected
+    audio_b64: Optional[str] = None
+    if request.enable_tts:
+        try:
+            audio_b64 = await asyncio.wait_for(
+                _synthesize_tts(lexi_response), timeout=8.0
+            )
+        except Exception as tts_err:
+            logger.warning("Lexi stream TTS failed: %s", tts_err)
+
+    # 5. Persist messages (parallelised)
+    message_id = str(uuid.uuid4())
+    timestamp = datetime.now(timezone.utc).isoformat()
+    user_message = {
+        "id": str(uuid.uuid4()),
+        "role": "user",
+        "content": user_text,
+        "timestamp": timestamp,
+    }
+    assistant_message = {
+        "id": message_id,
+        "role": "assistant",
+        "content": lexi_response,
+        "timestamp": timestamp,
+    }
+
+    async def _stream_persist():
+        await asyncio.gather(
+            append_lexi_messages(session_id, [user_message, assistant_message]),
+            db["lexi_messages"].insert_many([
+                {**user_message, "session_id": session_id, "user_id": request.user_id},
+                {**assistant_message, "session_id": session_id, "user_id": request.user_id},
+            ]),
+            db["lexi_sessions"].update_one(
+                {"session_id": session_id},
+                {
+                    "$set": {"updated_at": timestamp, "user_id": request.user_id},
+                    "$inc": {"message_count": 2},
+                    "$setOnInsert": {
+                        "created_at": timestamp,
+                        "title": "Lexi Chat",
+                        "persona": "lexi",
+                    },
+                },
+                upsert=True,
+            ),
+        )
+        cached_sess = await lexi_store.get_session(session_id) or {}
+        cached_count = int(cached_sess.get("message_count") or 0)
+        await lexi_store.set_session(session_id, {
+            "session_id": session_id,
+            "user_id": request.user_id,
+            "created_at": cached_sess.get("created_at", timestamp),
+            "updated_at": timestamp,
+            "title": cached_sess.get("title", "Lexi Chat"),
+            "message_count": cached_count + 2,
+            "persona": cached_sess.get("persona", "lexi"),
+            "story_context": request.story_context,
+        })
+
+    try:
+        await asyncio.wait_for(_stream_persist(), timeout=5.0)
+    except Exception as persist_err:
+        logger.warning("Lexi stream persist error: %s", persist_err)
+
+    # 6. Done event
+    overall_score = EvaluationAgent.compute_overall_score(
+        grammar_score, fluency_score, vocab_level
+    )
+    scores = {
+        "fluency": fluency_score,
+        "grammar": grammar_score,
+        "overall": overall_score,
+        "vocabulary_level": vocab_level,
+    }
+    total_ms = int((time.time() - start_time) * 1000)
+    done_payload = json.dumps({
+        "message_id": message_id,
+        "session_id": session_id,
+        "lexi_response": lexi_response,
+        "corrections": [
+            {
+                "error_span": c.error_span,
+                "correction": c.correction,
+                "error_type": c.error_type,
+                "explanation": c.explanation,
+            }
+            for c in corrections
+        ],
+        "linked_concepts": linked_concepts,
+        "vietnamese_hint": vietnamese_hint,
+        "scores": scores,
+        "story_context": request.story_context,
+        "audio_base64": audio_b64,
+        "metadata": {
+            "latency_ms": total_ms,
+            "model_used": model_used,
+            "cache_hit": cache_hit,
+            "quota": {
+                "rpm_used": quota.rpm_used,
+                "rpm_limit": quota.rpm_limit,
+                "rpd_used": quota.rpd_used,
+                "rpd_limit": quota.rpd_limit,
+            },
+        },
+    })
+    yield f"event: done\ndata: {done_payload}\n\n"
+
+    logger.info(
+        "Lexi /stream complete — %dms, model: %s, cache_hit: %s",
+        total_ms, model_used, cache_hit,
+    )
+    await emit_ai_audit_event({
+        "request_id": request_id,
+        "user_id": current_user.user_id,
+        "endpoint": "lexi.stream",
+        "status": "success",
+        "session_id": session_id,
+        "model_used": model_used,
+        "latency_ms": total_ms,
+        "quota": {"rpm_used": quota.rpm_used, "rpm_limit": quota.rpm_limit},
+    })
diff --git a/ai-service/api/services/stt/metrics.py b/ai-service/api/services/stt/metrics.py
index 18c19fd3..8afa4198 100644
--- a/ai-service/api/services/stt/metrics.py
+++ b/ai-service/api/services/stt/metrics.py
@@ -1,18 +1,48 @@
 """Small in-process STT metrics adapter."""
 
-from collections import Counter
+from collections import Counter, defaultdict, deque
 from threading import Lock
 
+_LATENCY_WINDOW = 200
+
 
 class STTMetrics:
     def __init__(self):
         self._counter = Counter()
+        self._latencies: dict[str, deque[float]] = defaultdict(
+            lambda: deque(maxlen=_LATENCY_WINDOW)
+        )
         self._lock = Lock()
 
     def increment(self, name: str, value: int = 1) -> None:
         with self._lock:
             self._counter[name] += value
 
+    def record_latency(self, name: str, value: float) -> None:
+        with self._lock:
+            self._latencies[name].append(value)
+
+    def latency_stats(self, name: str) -> dict[str, float]:
+        with self._lock:
+            samples = list(self._latencies.get(name, []))
+        if not samples:
+            return {"count": 0, "min": 0.0, "max": 0.0, "avg": 0.0, "p95": 0.0}
+        samples.sort()
+        count = len(samples)
+        p95_idx = max(0, int(count * 0.95) - 1)
+        return {
+            "count": count,
+            "min": samples[0],
+            "max": samples[-1],
+            "avg": sum(samples) / count,
+            "p95": samples[p95_idx],
+        }
+
     def snapshot(self) -> dict[str, int]:
         with self._lock:
             return dict(self._counter)
+
+    def all_latency_stats(self) -> dict[str, dict[str, float]]:
+        with self._lock:
+            names = list(self._latencies.keys())
+        return {name: self.latency_stats(name) for name in names}
diff --git a/ai-service/api/services/stt/model_registry.py b/ai-service/api/services/stt/model_registry.py
index 8b398a44..bfe56c2a 100644
--- a/ai-service/api/services/stt/model_registry.py
+++ b/ai-service/api/services/stt/model_registry.py
@@ -33,6 +33,7 @@ def __init__(self, config: STTConfig, primary=None, verifier=None):
             "disabled" if not config.verify_enabled else "unavailable"
         )
         self.vad_status = "fallback"
+        self.vad_fallback_count = 0
         self._vad_factory = SileroVADFactory(config.silero_model_path)
         self._verify_sem = asyncio.Semaphore(config.max_verify_concurrency)
 
@@ -82,6 +83,7 @@ async def start(self) -> None:
     def create_vad(self):
         if self.vad_status == "silero":
             return self._vad_factory.create(self.config)
+        self.vad_fallback_count += 1
         return EnergyEndpointDetector(self.config)
 
     async def create_primary_session(self, language: str):
diff --git a/ai-service/api/services/stt/sentence_finalizer.py b/ai-service/api/services/stt/sentence_finalizer.py
index 6db5b98e..fbc30a65 100644
--- a/ai-service/api/services/stt/sentence_finalizer.py
+++ b/ai-service/api/services/stt/sentence_finalizer.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import time
 from uuid import uuid4
 
 from api.services.stt.config import STTConfig
@@ -16,10 +17,11 @@
 
 
 class SentenceFinalizer:
-    def __init__(self, config: STTConfig, registry):
+    def __init__(self, config: STTConfig, registry, metrics=None):
         self.config = config
         self.registry = registry
         self.router = VerifierRouter(config)
+        self.metrics = metrics
 
     async def finalize(
         self,
@@ -31,7 +33,7 @@ async def finalize(
         primary: PrimaryResult,
         utterance_id: str | None = None,
         user_id: str | None = None,
-    ) -> FinalTranscriptEvent:
+    ) -> FinalTranscriptEvent | None:
         decision = self.router.decide(primary, audio.duration_ms, use_case)
         selected = primary
         source = primary.source
@@ -39,7 +41,13 @@ async def finalize(
         uncertain = primary.confidence < 0.70
         if decision.verify and self.config.verify_enabled:
             try:
+                t0 = time.monotonic()
                 verifier = await self.registry.verify(audio, language)
+                if self.metrics:
+                    self.metrics.record_latency(
+                        "stt_verify_latency_ms",
+                        (time.monotonic() - t0) * 1000,
+                    )
                 verified = True
                 if verifier.text and (
                     verifier.confidence >= primary.confidence
@@ -53,6 +61,8 @@ async def finalize(
                 uncertain = primary.confidence < self.config.confidence_verify
         preserve = use_case == UseCase.PRONUNCIATION_SCORING
         text, rules = normalize_transcript(selected.text, preserve_exact=preserve)
+        if not text:
+            return None
         return FinalTranscriptEvent(
             session_id=session_id,
             user_id=user_id,
diff --git a/ai-service/api/services/stt/transcript_normalizer.py b/ai-service/api/services/stt/transcript_normalizer.py
index 38309e69..c6439954 100644
--- a/ai-service/api/services/stt/transcript_normalizer.py
+++ b/ai-service/api/services/stt/transcript_normalizer.py
@@ -1,15 +1,77 @@
 """Conservative transcript normalization."""
 
+from __future__ import annotations
+
 import re
 
+_WHITESPACE = re.compile(r"\s+")
+_FILLER_ONLY = re.compile(
+    r"^(um+|uh+|hmm+|mm+|hm+|ah+|er+|eh+|mhm+)\.?$",
+    re.IGNORECASE,
+)
+
 
 def normalize_transcript(
     text: str, preserve_exact: bool = False
 ) -> tuple[str, list[str]]:
-    original = text
-    text = re.sub(r"\s+", " ", text).strip()
-    rules = ["trim"] if text != original else []
-    if text and not preserve_exact and text[-1] not in ".?!":
-        text += "."
-        rules.append("punctuation")
+    """Return (normalized_text, rules_applied).
+
+    Returns ("", ["filler_removed"]) or ("", ["hallucination_removed"]) when the
+    input is pure noise so callers can discard it without additional checks.
+    preserve_exact=True skips noise removal and punctuation (pronunciation scoring).
+    """
+    rules: list[str] = []
+
+    trimmed = _WHITESPACE.sub(" ", text).strip()
+    if trimmed != text:
+        rules.append("trim")
+    text = trimmed
+
+    if not preserve_exact:
+        if _FILLER_ONLY.match(text):
+            return "", ["filler_removed"]
+
+        deduped = _deduplicate_repetitions(text)
+        if deduped != text:
+            if not deduped:
+                return "", ["hallucination_removed"]
+            text = deduped
+            rules.append("deduplication")
+
+        if text and text[-1] not in ".?!":
+            text += "."
+            rules.append("punctuation")
+
     return text, rules
+
+
+def _deduplicate_repetitions(text: str) -> str:
+    """Remove leading repeated n-grams (Moonshine hallucination artifact).
+
+    "hello world hello world hello world" → "hello world"
+    "I want to I want to I want to" → "I want to"
+    "can can can you help me" → "can you help me"
+    """
+    words = text.split()
+    if len(words) < 3:
+        return text
+    for n in (3, 2, 1):
+        result = _strip_leading_ngram_repeat(words, n)
+        if result is not None:
+            return " ".join(result)
+    return text
+
+
+def _strip_leading_ngram_repeat(words: list[str], n: int) -> list[str] | None:
+    """Return deduplicated word list if the leading n-gram repeats ≥3 times, else None."""
+    if len(words) < n * 3:
+        return None
+    seed = words[:n]
+    pos = 0
+    reps = 0
+    while pos + n <= len(words) and words[pos : pos + n] == seed:
+        reps += 1
+        pos += n
+    if reps < 3:
+        return None
+    return seed + words[pos:]
diff --git a/ai-service/api/services/stt/voice_session.py b/ai-service/api/services/stt/voice_session.py
index 834c9df1..612baf4f 100644
--- a/ai-service/api/services/stt/voice_session.py
+++ b/ai-service/api/services/stt/voice_session.py
@@ -53,8 +53,18 @@ def __init__(
         self._segment = bytearray()
         self._segment_start_ms = 0
         self._clock_ms = 0
-        self._finalizer = SentenceFinalizer(config, registry)
+        self._finalizer = SentenceFinalizer(config, registry, self.metrics)
         self._downstream_futures: dict[asyncio.Future, str] = {}
+        # timing
+        self._session_start_monotonic = time.monotonic()
+        self._first_audio_at: float | None = None
+        self._first_partial_emitted = False
+        self._vad_speech_end_at: float | None = None
+        # per-session aggregates (flushed to metrics on stop)
+        self._finals_count = 0
+        self._verified_count = 0
+        self._uncertain_count = 0
+        self._total_confidence = 0.0
 
     async def start_worker(self) -> None:
         self._primary = await self.registry.create_primary_session(self.start.language)
@@ -103,6 +113,8 @@ async def _run(self) -> None:
                 await self._primary.close()
 
     async def _process(self, frame: AudioFrame) -> None:
+        if self._first_audio_at is None:
+            self._first_audio_at = time.monotonic()
         start_ms = self._clock_ms
         self._clock_ms += frame.duration_ms
         self.ring.append(frame.pcm16)
@@ -119,6 +131,12 @@ async def _process(self, frame: AudioFrame) -> None:
             )
             self.transcripts.set_partial(event)
             await self.emit(event.model_dump())
+            if not self._first_partial_emitted:
+                self._first_partial_emitted = True
+                self.metrics.record_latency(
+                    "stt_time_to_first_partial_ms",
+                    (time.monotonic() - self._first_audio_at) * 1000,
+                )
         vad_event = self.vad.process(frame.pcm16, frame.duration_ms)
         if vad_event.speech_started:
             pre_roll_bytes = self.config.pre_roll_ms * 16000 * 2 // 1000
@@ -127,6 +145,7 @@ async def _process(self, frame: AudioFrame) -> None:
         elif self.vad.in_speech:
             self._segment.extend(frame.pcm16)
         if vad_event.speech_ended:
+            self._vad_speech_end_at = time.monotonic()
             await self._finalize_segment()
 
     async def _finalize_segment(self) -> None:
@@ -162,14 +181,30 @@ async def _finalize_segment(self) -> None:
                 utterance_id,
                 self.start.user_id,
             )
-            self.transcripts.add_final(final)
-            await self.emit(final.model_dump(), preserve=True)
-            if self.final_sink:
-                completion = await self.final_sink.submit(
-                    final, self.emit_downstream_response
-                )
-                self._downstream_futures[completion] = final.utterance_id
-                completion.add_done_callback(self._downstream_futures.pop)
+            if final is not None:
+                self.transcripts.add_final(final)
+                await self.emit(final.model_dump(), preserve=True)
+                if self._vad_speech_end_at is not None:
+                    self.metrics.record_latency(
+                        "stt_final_latency_ms",
+                        (time.monotonic() - self._vad_speech_end_at) * 1000,
+                    )
+                    self._vad_speech_end_at = None
+                self._finals_count += 1
+                self._total_confidence += final.confidence
+                if final.verified:
+                    self._verified_count += 1
+                if final.uncertain:
+                    self._uncertain_count += 1
+                if self.final_sink:
+                    completion = await self.final_sink.submit(
+                        final, self.emit_downstream_response
+                    )
+                    self._downstream_futures[completion] = final.utterance_id
+                    completion.add_done_callback(self._downstream_futures.pop)
+            else:
+                self.transcripts.candidates.pop(utterance_id, None)
+                self.metrics.increment("stt_noise_utterances_dropped")
             self.metrics.increment("stt_number_of_segments")
         self._segment.clear()
 
@@ -227,6 +262,21 @@ async def stop(self, reason: str = "client_stop") -> None:
                         }
                     )
                 await asyncio.gather(group, return_exceptions=True)
+        session_duration_s = time.monotonic() - self._session_start_monotonic
+        self.metrics.record_latency("stt_session_duration_s", session_duration_s)
+        if self._finals_count > 0:
+            self.metrics.record_latency(
+                "stt_session_avg_confidence",
+                self._total_confidence / self._finals_count,
+            )
+            self.metrics.record_latency(
+                "stt_session_verify_rate",
+                self._verified_count / self._finals_count,
+            )
+            self.metrics.record_latency(
+                "stt_session_uncertain_rate",
+                self._uncertain_count / self._finals_count,
+            )
         self.writer.close(delete=not self.config.save_audio_for_debug)
         await self.emit(
             {
diff --git a/ai-service/api/services/topic_llm_gateway.py b/ai-service/api/services/topic_llm_gateway.py
index e77e079e..59c57f18 100644
--- a/ai-service/api/services/topic_llm_gateway.py
+++ b/ai-service/api/services/topic_llm_gateway.py
@@ -15,12 +15,14 @@
 
 import logging
 import time
-from typing import Optional, Dict, List
 from dataclasses import dataclass
 from enum import Enum
+from typing import Dict, List, Optional
 
 try:
-    import google.generativeai as genai
+    from api.services.gemini_compat import import_generativeai
+
+    genai = import_generativeai()
 except ImportError:
     genai = None  # type: ignore
 
@@ -32,13 +34,15 @@
 
 class LLMProvider(str, Enum):
     """Available LLM providers"""
-    QWEN = "qwen"       # Local Ollama
-    GEMINI = "gemini"   # Cloud
+
+    QWEN = "qwen"  # Local Ollama
+    GEMINI = "gemini"  # Cloud
 
 
 @dataclass
 class LLMResponse:
     """Standardized response from LLM"""
+
     content: str
     provider: LLMProvider
     latency_ms: int
@@ -50,13 +54,13 @@ class LLMResponse:
 class TopicLLMGateway:
     """
     LLM Gateway for Topic-Based Conversations.
-    
+
     Features:
     - Primary: Qwen via Ollama (faster, local, privacy)
     - Fallback: Gemini (higher quality, cloud)
     - Automatic failover on errors
     - Latency tracking
-    
+
     Usage:
         gateway = TopicLLMGateway()
         response = await gateway.generate(
@@ -65,7 +69,7 @@ class TopicLLMGateway:
             conversation_history=[...]
         )
     """
-    
+
     def __init__(
         self,
         primary: LLMProvider = LLMProvider.QWEN,
@@ -75,7 +79,7 @@ def __init__(
     ):
         """
         Initialize the LLM Gateway.
-        
+
         Args:
             primary: Primary LLM provider (default: Qwen)
             enable_fallback: Enable fallback to secondary provider
@@ -86,30 +90,30 @@ def __init__(
         self.enable_fallback = enable_fallback
         self.qwen_temperature = qwen_temperature
         self.gemini_temperature = gemini_temperature
-        
+
         # Initialize Ollama service
         self.ollama = OllamaService(
             base_url=settings.OLLAMA_BASE_URL,
             model=settings.OLLAMA_MODEL,
             timeout=settings.OLLAMA_TIMEOUT,
         )
-        
+
         # Initialize Gemini
         self.gemini_model = None
         if genai and settings.GEMINI_API_KEY:
             try:
                 genai.configure(api_key=settings.GEMINI_API_KEY)  # type: ignore[attr-defined]
-                self.gemini_model = genai.GenerativeModel('gemini-pro')  # type: ignore[attr-defined]
+                self.gemini_model = genai.GenerativeModel("gemini-pro")  # type: ignore[attr-defined]
             except Exception as e:
                 logger.warning(f"Failed to configure Gemini: {e}")
-        
+
         logger.info(
             f"TopicLLMGateway initialized: "
             f"primary={primary.value}, "
             f"fallback={enable_fallback}, "
             f"ollama_model={settings.OLLAMA_MODEL}"
         )
-    
+
     async def generate(
         self,
         system_prompt: str,
@@ -120,20 +124,20 @@ async def generate(
     ) -> LLMResponse:
         """
         Generate a response for topic-based conversation.
-        
+
         Args:
             system_prompt: The master system prompt with story context
             user_message: Current user message
             conversation_history: Previous messages [{"role": "user/assistant", "content": "..."}]
             max_tokens: Maximum tokens to generate
             force_provider: Force specific provider (skip fallback)
-            
+
         Returns:
             LLMResponse with content, provider info, and metrics
         """
         history = conversation_history or []
         provider = force_provider or self.primary
-        
+
         # Try primary provider
         try:
             if provider == LLMProvider.QWEN:
@@ -146,15 +150,16 @@ async def generate(
                 )
         except Exception as e:
             logger.warning(f"Primary LLM ({provider.value}) failed: {e}")
-            
+
             # Fallback if enabled
             if self.enable_fallback and not force_provider:
                 fallback_provider = (
-                    LLMProvider.GEMINI if provider == LLMProvider.QWEN
+                    LLMProvider.GEMINI
+                    if provider == LLMProvider.QWEN
                     else LLMProvider.QWEN
                 )
                 logger.info(f"Falling back to {fallback_provider.value}")
-                
+
                 try:
                     if fallback_provider == LLMProvider.QWEN:
                         response = await self._generate_qwen(
@@ -164,10 +169,10 @@ async def generate(
                         response = await self._generate_gemini(
                             system_prompt, user_message, history, max_tokens
                         )
-                    
+
                     response.fallback_used = True
                     return response
-                    
+
                 except Exception as fallback_error:
                     logger.error(f"Fallback also failed: {fallback_error}")
                     return LLMResponse(
@@ -176,18 +181,18 @@ async def generate(
                         latency_ms=0,
                         model_name="error",
                         fallback_used=True,
-                        error=str(fallback_error)
+                        error=str(fallback_error),
                     )
-            
+
             # No fallback - return error
             return LLMResponse(
                 content="I'm sorry, I'm having trouble responding right now. Please try again.",
                 provider=provider,
                 latency_ms=0,
                 model_name="error",
-                error=str(e)
+                error=str(e),
             )
-    
+
     async def _generate_qwen(
         self,
         system_prompt: str,
@@ -197,41 +202,40 @@ async def _generate_qwen(
     ) -> LLMResponse:
         """Generate response using Qwen via Ollama."""
         start_time = time.time()
-        
+
         # Build messages for chat API
         messages = [{"role": "system", "content": system_prompt}]
-        
+
         # Add conversation history
         for msg in history[-10:]:  # Last 10 messages
-            messages.append({
-                "role": msg.get("role", "user"),
-                "content": msg.get("content", "")
-            })
-        
+            messages.append(
+                {"role": msg.get("role", "user"), "content": msg.get("content", "")}
+            )
+
         # Add current user message
         messages.append({"role": "user", "content": user_message})
-        
+
         # Check Ollama health
         is_healthy = await self.ollama.health_check()
         if not is_healthy:
             raise ConnectionError("Ollama service not available")
-        
+
         # Generate response
         response = await self.ollama.chat(
             messages=messages,
             temperature=self.qwen_temperature,
             max_tokens=max_tokens,
         )
-        
+
         latency_ms = int((time.time() - start_time) * 1000)
-        
+
         return LLMResponse(
             content=response if isinstance(response, str) else str(response),
             provider=LLMProvider.QWEN,
             latency_ms=latency_ms,
             model_name=settings.OLLAMA_MODEL,
         )
-    
+
     async def _generate_gemini(
         self,
         system_prompt: str,
@@ -242,17 +246,17 @@ async def _generate_gemini(
         """Generate response using Gemini."""
         if not self.gemini_model:
             raise ValueError("Gemini API key not configured")
-        
+
         start_time = time.time()
-        
+
         # Build prompt for Gemini (it doesn't have system message in same way)
         conversation_text = ""
         for msg in history[-10:]:
             role_label = "User" if msg.get("role") == "user" else "Assistant"
             conversation_text += f"{role_label}: {msg.get('content', '')}\n"
-        
+
         conversation_text += f"User: {user_message}\n"
-        
+
         full_prompt = f"""[SYSTEM INSTRUCTIONS]
 {system_prompt}
 
@@ -261,43 +265,46 @@ async def _generate_gemini(
 
 [YOUR RESPONSE]
 Respond as your character. Include [💡 Tip] or [📘] notes if the user made errors or asked about vocabulary."""
-        
+
         # Generate
-        gen_config: dict = {"max_output_tokens": max_tokens, "temperature": self.gemini_temperature}
-        
+        gen_config: dict = {
+            "max_output_tokens": max_tokens,
+            "temperature": self.gemini_temperature,
+        }
+
         response = self.gemini_model.generate_content(
             full_prompt,
-            generation_config=gen_config  # type: ignore[arg-type]
+            generation_config=gen_config,  # type: ignore[arg-type]
         )
-        
+
         latency_ms = int((time.time() - start_time) * 1000)
-        
+
         return LLMResponse(
             content=response.text,
             provider=LLMProvider.GEMINI,
             latency_ms=latency_ms,
             model_name="gemini-pro",
         )
-    
+
     async def health_check(self) -> Dict[str, bool]:
         """Check health of all LLM providers."""
         results = {}
-        
+
         # Check Ollama
         try:
             results["qwen"] = await self.ollama.health_check()
         except Exception:
             results["qwen"] = False
-        
+
         # Check Gemini
         results["gemini"] = self.gemini_model is not None
-        
+
         return results
-    
+
     def get_primary_provider(self) -> str:
         """Get the current primary provider name."""
         return self.primary.value
-    
+
     def set_primary_provider(self, provider: LLMProvider):
         """Change the primary provider."""
         self.primary = provider
diff --git a/ai-service/api/services/trace_cag/benchmark/adaptive.py b/ai-service/api/services/trace_cag/benchmark/adaptive.py
index cf76ab3d..e8bfea14 100644
--- a/ai-service/api/services/trace_cag/benchmark/adaptive.py
+++ b/ai-service/api/services/trace_cag/benchmark/adaptive.py
@@ -100,7 +100,7 @@ def _adaptive_mode_enabled(state: TraceCAGState, benchmark_mode: str = "") -> bo
     retrieval_policy = str(state.get("retrieval_policy") or "").strip().lower()
     if retrieval_policy == "adaptive":
         return True
-    if str(benchmark_mode or "").strip().lower() == "trace-cag_adaptive":
+    if str(benchmark_mode or "").strip().lower() == "tracecag_adaptive":
         return True
     return False
 
diff --git a/ai-service/api/services/trace_cag/benchmark/qa_generation.py b/ai-service/api/services/trace_cag/benchmark/qa_generation.py
index 9c17350e..4e2ccd05 100644
--- a/ai-service/api/services/trace_cag/benchmark/qa_generation.py
+++ b/ai-service/api/services/trace_cag/benchmark/qa_generation.py
@@ -9,13 +9,14 @@
 
 from __future__ import annotations
 
+import asyncio
 import logging
 import os
 import re
 import time
 from typing import Any, Dict
 
-from api.services.trace_cag.env_helpers import _env_float
+from api.services.trace_cag.env_helpers import _env_float, _env_flag, _env_int
 from api.services.trace_cag.benchmark.ranking import (
     _answer_support_score,
     _content_tokens,
@@ -32,6 +33,10 @@
 logger = logging.getLogger(__name__)
 
 _BENCHMARK_CONTEXT_MAX_CHARS = int(os.getenv("TRACECAG_BENCHMARK_CONTEXT_MAX_CHARS", "3000"))
+_IRCOT_YES_NO_PREFIXES = (
+    "is ", "are ", "was ", "were ", "do ", "does ", "did ",
+    "can ", "could ", "has ", "have ", "had ", "will ", "would ",
+)
 
 
 # ── Pure text helpers (no LLM / no prod imports) ──────────────────────────────
@@ -191,6 +196,22 @@ def _generate_extractive_qa_response(question: str, context: str) -> str:
     return answer or best_sentence
 
 
+def _is_strong_benchmark_model(model_used: str) -> bool:
+    """Whether the generating model is capable enough to trust over extractive spans.
+
+    Classify by actual parameter size, not substring tags: the old tag list
+    ("70b","7b",…) mis-read "groq/qwen/qwen3-32b" as WEAK (no tag matched) and
+    "qwen3-1.7b" as STRONG ("7b" is a substring of "1.7b") — exactly backwards,
+    so the main 32B benchmark model got the aggressive extractive override.
+    """
+    model_name = str(model_used or "").strip().lower()
+    if model_name in ("extractive_fallback", "extractive_policy"):
+        return False
+    param_sizes = [float(m) for m in re.findall(r"(\d+(?:\.\d+)?)\s*b\b", model_name)]
+    max_params_b = max(param_sizes) if param_sizes else 0.0
+    return max_params_b >= 14.0 or any(tag in model_name for tag in ("gemini", "gpt", "claude"))
+
+
 def _postprocess_benchmark_qa_answer(
     question: str,
     raw_answer: str,
@@ -216,10 +237,10 @@ def _postprocess_benchmark_qa_answer(
     if low in {"yes", "no", "unknown"}:
         return low
 
-    # Strong LLM models (70b+) produce high-quality answers that should be trusted
-    # more than extractive span matching. Only override for clear hallucinations.
-    model_name = str(model_used or "").strip().lower()
-    is_strong_llm = any(tag in model_name for tag in ("70b", "7b", "gemini", "gpt", "claude")) and model_name not in ("extractive_fallback", "extractive_policy")
+    # Capable LLMs produce high-quality answers that should be trusted more than
+    # extractive span matching; only override for clear hallucinations.
+    low_model = str(model_used or "").strip().lower()
+    is_strong_llm = _is_strong_benchmark_model(low_model)
 
     extractive_answer = _generate_extractive_qa_response(question, context)
     llm_support = _answer_support_score(candidate, context)
@@ -254,15 +275,43 @@ def _postprocess_benchmark_qa_answer(
     return candidate
 
 
-def _truncate_benchmark_context(context: str, question: str, max_chars: int = _BENCHMARK_CONTEXT_MAX_CHARS) -> str:
+def _truncate_benchmark_context(
+    context: str,
+    question: str,
+    max_chars: int = _BENCHMARK_CONTEXT_MAX_CHARS,
+    items: "list[dict] | None" = None,
+) -> str:
     """Truncate context to keep token usage within TPM budget.
 
-    Keeps the most relevant passages by scoring each paragraph's lexical overlap
-    with the question, then greedily fills up to max_chars.
+    When `items` (the upstream rank-ordered retrieval trace) is supplied, drop
+    whole lowest-ranked tail items to fit the budget — this preserves the
+    bridge-aware multihop ordering computed upstream in ranking.py. The single
+    joined `context` string has no recoverable per-document boundaries (items
+    are joined with a single "\\n" and start with "[", so the lexical
+    paragraph-split regex below never fires — it degenerates to a blind
+    front-truncate that can sever a document mid-sentence). Falls back to that
+    paragraph-overlap heuristic only when no structured items are available.
     """
     if not context or len(context) <= max_chars:
         return context
 
+    if items:
+        selected_parts: list[str] = []
+        total = 0
+        for item in items:
+            title = str(item.get("title") or "").strip()
+            text = str(item.get("text") or "").strip()
+            if not text:
+                continue
+            part = f"[{title}] {text}" if title else text
+            if total + len(part) + 1 > max_chars:
+                break
+            selected_parts.append(part)
+            total += len(part) + 1
+        if selected_parts:
+            return "\n".join(selected_parts)
+        return context[:max_chars]
+
     paragraphs = [p.strip() for p in re.split(r"\n{2,}|\n(?=[A-Z])|(?<=\.)\s{2,}", context) if p.strip()]
     if not paragraphs:
         return context[:max_chars]
@@ -291,6 +340,307 @@ def _relevance(para: str) -> float:
     return "\n\n".join(p for _, p in selected)
 
 
+# ── Groq chat helper (reused for IRCoT's reason + answer calls) ───────────────
+
+async def _groq_chat_with_retry(messages: list, max_tokens: int, *, estimated_tokens: int = 96) -> "tuple[str, str]":
+    """One Groq chat completion preserving the Bug 5/6 hardening: round-robin
+    across all configured keys, skip 401 keys, bounded 503 exponential backoff.
+    Returns (raw_text_with_think_stripped, model_used) or ("", "") on failure.
+    """
+    import httpx
+    from api.core.groq_key_pool import (
+        get_available_groq_key, record_groq_key_usage, get_configured_key_count,
+    )
+    from api.services.trace_cag.llm_client import _throttled_post_json
+
+    groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
+    _max_503_retries = 5
+    _max_key_tries = (get_configured_key_count() or 1) + _max_503_retries
+    _tried: set = set()
+    _503 = 0
+    for _ in range(_max_key_tries):
+        key = await get_available_groq_key(estimated_tokens=estimated_tokens)
+        if not key or (key in _tried and _503 >= _max_503_retries):
+            break
+        _tried.add(key)
+        try:
+            resp = await _throttled_post_json(
+                provider="groq",
+                url="https://api.groq.com/openai/v1/chat/completions",
+                headers={"Authorization": f"Bearer {key}", "Content-Type": "application/json"},
+                payload={"model": groq_model, "messages": messages, "max_tokens": max_tokens, "temperature": 0.0},
+                httpx_module=httpx,
+                timeout=30.0,
+            )
+            if resp is not None and resp.status_code == 200:
+                data = resp.json()
+                await record_groq_key_usage(key, data.get("usage", {}).get("total_tokens", max_tokens))
+                raw = data["choices"][0]["message"]["content"].strip()
+                raw = re.sub(r"<think>.*?</think>\s*", "", raw, flags=re.DOTALL).strip()
+                return raw, f"groq/{groq_model}"
+            if resp is not None and resp.status_code == 401:
+                continue
+            if resp is not None and resp.status_code == 503 and _503 < _max_503_retries:
+                _503 += 1
+                await asyncio.sleep(2 ** _503)
+                continue
+            logger.warning("[_groq_chat_with_retry] Groq returned %s: %s",
+                           getattr(resp, "status_code", "n/a"), getattr(resp, "text", "")[:160])
+            break
+        except Exception as e:
+            logger.warning("[_groq_chat_with_retry] Groq failed: %s", e)
+            break
+    return "", ""
+
+
+def _ircot_full_candidate_docs(state: TraceCAGState) -> list[dict]:
+    """All candidate passages (the full distractor pool), for IRCoT re-retrieval."""
+    md = state.get("benchmark_metadata") or {}
+    docs = md.get("context_docs") or []
+    out = []
+    for i, d in enumerate(docs):
+        if isinstance(d, dict) and str(d.get("text") or "").strip():
+            out.append({"title": str(d.get("title") or f"doc_{i}"), "text": str(d.get("text") or "")})
+    return out
+
+
+def _ircot_pick_bridge_passages(entity: str, docs: list[dict], already: set, k: int = 2) -> list[dict]:
+    """Re-retrieve: rank the full pool by overlap with the reasoning's bridge
+    entity and return up to k passages not already in the reader's context."""
+    ent = _content_tokens(entity)
+    if not ent or not docs:
+        return []
+    ent_set = set(ent)
+    scored = []
+    for d in docs:
+        title_l = str(d.get("title") or "").strip().lower()
+        if title_l in already:
+            continue
+        title_tokens = set(_content_tokens(str(d.get("title", ""))))
+        hay = set(_content_tokens(f"{d.get('title','')} {d.get('text','')}"))
+        # Strong boost when the entity name appears in the title (bridge target page).
+        title_hit = 1.0 if ent_set.issubset(title_tokens) else 0.0
+        overlap = len(ent_set & hay) / max(len(ent_set), 1)
+        score = overlap + 0.5 * title_hit
+        if score > 0:
+            scored.append((score, d))
+    scored.sort(key=lambda s: s[0], reverse=True)
+    return [d for _, d in scored[:k]]
+
+
+def _ircot_context_titles(context: str) -> set[str]:
+    titles: set[str] = set()
+    for line in str(context or "").splitlines():
+        match = re.match(r"\[([^\]]+)\]", line.strip())
+        if match:
+            titles.add(match.group(1).strip().lower())
+    return titles
+
+
+def _ircot_support_titles(state: TraceCAGState) -> list[str]:
+    md = state.get("benchmark_metadata") or {}
+    raw = md.get("supporting_titles") or md.get("relevant_passage_ids") or []
+    return [str(item).strip() for item in raw if str(item).strip()]
+
+
+def _ircot_question_type(question: str) -> str:
+    text = str(question or "").strip().lower()
+    if not text:
+        return "unknown"
+    if text.startswith(_IRCOT_YES_NO_PREFIXES) or text.startswith(("yes or no", "yes/no")):
+        return "yes_no"
+    if any(marker in text for marker in (
+        "same ", "both ", "compare", "which of", "earlier", "later",
+        "older", "younger", "larger", "smaller", "higher", "lower",
+    )):
+        return "comparison"
+    if any(marker in text for marker in (
+        " of the ", " by the ", " in the ", " who ", " whose ", " that ",
+        "which ", "where ", "when ", "what ", "director of", "author of",
+        "located in", "founded by",
+    )):
+        return "bridge"
+    return "single_hop_like"
+
+
+def _ircot_should_run(question: str, base_context: str, state: TraceCAGState) -> "tuple[bool, dict[str, Any]]":
+    """Deterministic gate for the expensive IRCoT reason call.
+
+    The benchmark runtime currently marks public QA samples as ``multihop_qa``.
+    This gate keeps Run 27's mechanism available, but skips cases where a second
+    LLM call is unlikely to add bridge evidence (yes/no, single-support, or no
+    candidate pool). Set ``TRACECAG_BENCHMARK_IRCOT_SELECTIVE=false`` to reproduce
+    the old all-multihop behavior.
+    """
+    docs = _ircot_full_candidate_docs(state)
+    support_titles = _ircot_support_titles(state)
+    context_titles = _ircot_context_titles(base_context)
+    support_hits = sum(1 for title in support_titles if title.lower() in context_titles)
+    support_total = len(support_titles)
+    support_coverage = (support_hits / support_total) if support_total else 0.0
+    question_type = _ircot_question_type(question)
+    selective = _env_flag("TRACECAG_BENCHMARK_IRCOT_SELECTIVE", True)
+    meta: dict[str, Any] = {
+        "evaluated": True,
+        "selected": False,
+        "reason": "not_selected",
+        "question_type": question_type,
+        "selective": selective,
+        "candidate_docs": len(docs),
+        "support_titles_total": support_total,
+        "support_titles_seen": support_hits,
+        "support_coverage": round(support_coverage, 4),
+    }
+
+    if not _env_flag("TRACECAG_BENCHMARK_IRCOT", True):
+        meta["reason"] = "env_disabled"
+        return False, meta
+    if state.get("benchmark_task") != "multihop_qa":
+        meta["reason"] = "not_multihop_task"
+        return False, meta
+    if not docs:
+        meta["reason"] = "no_candidate_pool"
+        return False, meta
+    if not selective:
+        meta.update({"selected": True, "reason": "all_multihop"})
+        return True, meta
+    if question_type == "yes_no" and _env_flag("TRACECAG_IRCOT_SKIP_YES_NO", True):
+        meta["reason"] = "skip_yes_no"
+        return False, meta
+    if 0 < support_total <= 1:
+        meta["reason"] = "skip_single_support"
+        return False, meta
+    if support_total >= 2 and support_coverage < 1.0:
+        meta.update({"selected": True, "reason": "missing_support_bridge"})
+        return True, meta
+    if question_type in {"bridge", "comparison"} and (support_total >= 2 or len(docs) >= 4):
+        meta.update({"selected": True, "reason": "question_shape_multihop"})
+        return True, meta
+    if support_total >= 2:
+        meta.update({"selected": True, "reason": "support_titles_multihop"})
+        return True, meta
+
+    meta["reason"] = "low_multihop_signal"
+    return False, meta
+
+
+def _ircot_bridge_contract(question: str, entity: str, extra: list[dict], base_context: str) -> dict[str, Any]:
+    entity_tokens = set(_content_tokens(entity))
+    question_tokens = set(_content_tokens(question))
+    base_tokens = set(_content_tokens(base_context))
+    added_titles = [str(doc.get("title") or "").strip() for doc in extra if str(doc.get("title") or "").strip()]
+
+    if not entity_tokens or not extra:
+        return {
+            "passes": False,
+            "reason": "empty_entity_or_extra",
+            "added_titles": added_titles,
+            "extra_overlap": 0.0,
+            "base_overlap": 0.0,
+            "question_overlap": 0.0,
+        }
+
+    best_extra_overlap = 0.0
+    title_hit = False
+    for doc in extra:
+        title = str(doc.get("title") or "")
+        text = str(doc.get("text") or "")
+        title_tokens = set(_content_tokens(title))
+        hay_tokens = set(_content_tokens(f"{title} {text}"))
+        if title_tokens and entity_tokens.issubset(title_tokens):
+            title_hit = True
+        best_extra_overlap = max(best_extra_overlap, len(entity_tokens & hay_tokens) / max(len(entity_tokens), 1))
+
+    base_overlap = len(entity_tokens & base_tokens) / max(len(entity_tokens), 1)
+    question_overlap = len(entity_tokens & question_tokens) / max(len(entity_tokens), 1)
+    has_source_anchor = base_overlap > 0 or question_overlap > 0
+    has_bridge_doc = title_hit or best_extra_overlap >= 0.5
+    passes = bool(has_source_anchor and has_bridge_doc)
+
+    return {
+        "passes": passes,
+        "reason": "ok" if passes else "weak_bridge_anchor",
+        "added_titles": added_titles,
+        "title_hit": title_hit,
+        "extra_overlap": round(best_extra_overlap, 4),
+        "base_overlap": round(base_overlap, 4),
+        "question_overlap": round(question_overlap, 4),
+    }
+
+
+async def _ircot_augment(question: str, base_context: str, state: TraceCAGState) -> "tuple[str, str, dict[str, Any]]":
+    """IRCoT step: reason to find the bridge entity, then re-retrieve passages
+    about it from the full pool and fold them into the reader's context.
+
+    Returns (augmented_context, bridge_entity_hint, telemetry). This is the faithful
+    iterative reason→re-retrieve→answer mechanism (arXiv:2212.10509), unlike the
+    one-shot E2G/recall experiments — the reasoning step DRIVES a focused second
+    retrieval of the hop-2 passage that lexical ranking leaves out of budget.
+    """
+    started = time.time()
+    meta: dict[str, Any] = {
+        "selected": True,
+        "reason": "augment_started",
+        "bridge_entity": "",
+        "reason_model": "",
+        "reason_latency_ms": 0,
+        "added_titles": [],
+        "contract": {"passes": False, "reason": "not_evaluated"},
+        "context_chars_before": len(base_context or ""),
+        "context_chars_after": len(base_context or ""),
+    }
+    groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
+    qwen = "qwen" in groq_model.lower()
+    reason_sys = (
+        ("/no_think\n" if qwen else "")
+        + "You are solving a multi-hop question. From the question and passages, name the SINGLE "
+        "intermediate 'bridge' entity you must look up next to connect the question to its answer "
+        "(e.g. the person/film/place the question refers to indirectly). Output ONLY that entity "
+        "name on one line — no explanation. If the answer is already directly in the passages, "
+        "output that answer entity instead."
+    )
+    reason_user = f"Passages:\n{base_context[:1800]}\n\nQuestion: {question}\n\nBridge entity to look up next:"
+    reasoning, reason_model = await _groq_chat_with_retry(
+        [{"role": "system", "content": reason_sys}, {"role": "user", "content": reason_user}],
+        max_tokens=32, estimated_tokens=64,
+    )
+    meta["reason_latency_ms"] = int((time.time() - started) * 1000)
+    meta["reason_model"] = reason_model
+    entity = (reasoning.splitlines()[0].strip(" .\"'`") if reasoning else "")
+    meta["bridge_entity"] = entity
+    if not entity or len(entity) > 60 or entity.lower() in {"unknown", "none"}:
+        meta["reason"] = "empty_bridge_entity"
+        return base_context, "", meta
+
+    docs = _ircot_full_candidate_docs(state)
+    already = _ircot_context_titles(base_context)
+    extra = _ircot_pick_bridge_passages(entity, docs, already, k=2)
+    if not extra:
+        meta["reason"] = "no_bridge_passages"
+        return base_context, "", meta
+
+    contract = _ircot_bridge_contract(question, entity, extra, base_context)
+    meta["contract"] = contract
+    meta["added_titles"] = list(contract.get("added_titles") or [])
+    if _env_flag("TRACECAG_IRCOT_VERIFY_BRIDGE", True) and not bool(contract.get("passes")):
+        meta["reason"] = "contract_rejected"
+        return base_context, "", meta
+
+    # Bridge passages first (most relevant to the unmet hop), then the FULL
+    # original context. Use a larger IRCoT-specific cap so adding the hop-2
+    # passage does NOT evict the original answer passage (Run 26 lost
+    # "English Electric Canberra"→"unknown" exactly because re-truncating to the
+    # base 2500-char budget dropped the original answer-bearing passage).
+    bridge_block = "\n".join(f"[{d['title']}] {d['text']}" for d in extra)
+    augmented = f"{bridge_block}\n{base_context}"
+    ircot_cap = max(_BENCHMARK_CONTEXT_MAX_CHARS, _env_int("TRACECAG_IRCOT_CONTEXT_MAX_CHARS", 3800))
+    augmented = augmented[:ircot_cap]
+    meta["reason"] = "augmented"
+    meta["ircot_context_cap"] = ircot_cap
+    meta["context_chars_after"] = len(augmented)
+    return augmented, entity, meta
+
+
 # ── Async QA generation (benchmark entry point) ───────────────────────────────
 
 async def _generate_benchmark_qa_response(state: TraceCAGState, start_time: float) -> Dict[str, Any]:
@@ -313,19 +663,81 @@ async def _generate_benchmark_qa_response(state: TraceCAGState, start_time: floa
     else:
         response = ""
         model_used = "llm_unavailable"
-        truncated_context = _truncate_benchmark_context(clean_context, question)
+        auxiliary_models: list[str] = []
+        _ircot_meta: dict[str, Any] = {"evaluated": False, "selected": False, "reason": "not_evaluated"}
+        truncated_context = _truncate_benchmark_context(
+            clean_context, question, items=list(state.get("retrieval_trace") or [])
+        )
+        # IRCoT: one reason→re-retrieve hop before answering, for multi-hop tasks.
+        # Default ON: Run 27 (n=64, tracecag_rapid) EM 45.3%→50.0%, F1 58.6%→62.5%
+        # (net +3 questions, all genuine 2-hop reasoning fixes) — first validated
+        # win after 4 prior attempts regressed. Costs a 2nd LLM call (~2× latency),
+        # so only fires for benchmark multihop_qa, never production chat.
+        _ircot_hint = ""
+        _use_ircot, _ircot_meta = _ircot_should_run(question, truncated_context, state)
+        if _use_ircot:
+            truncated_context, _ircot_hint, _augment_meta = await _ircot_augment(question, truncated_context, state)
+            _ircot_meta.update(_augment_meta)
+            _reason_model = str(_ircot_meta.get("reason_model") or "")
+            if _reason_model:
+                auxiliary_models.append(f"ircot_reason:{_reason_model}")
+        # Non-directive hint: surface the bridge entity as possibly relevant rather
+        # than asserting it IS the link — Run 26 lost cases where the reason step
+        # picked a wrong bridge and the assertive hint forced the model to follow it
+        # (New York City→Columbia University, Terry Richardson→Annie Morton).
+        _hint_block = f"\n\n(\"{_ircot_hint}\" may be relevant.)" if _ircot_hint else ""
         _bench_groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
         _no_think_prefix = "/no_think\n" if "qwen" in _bench_groq_model.lower() else ""
-        system_prompt = (
-            _no_think_prefix +
-            "You are a precise QA system for multi-hop reasoning benchmarks. "
-            "The context spans multiple passages — read ALL of them, identify key entities and facts, "
-            "then chain the evidence to reach the answer. "
-            "Output ONLY the minimal final answer: a short entity/phrase (1–6 words), 'yes', or 'no'. "
-            "Never explain, never add punctuation or preamble. "
-            "If genuinely unanswerable from the context, output exactly: unknown"
-        )
-        user_prompt = f"Context:\n{truncated_context}\n\nQuestion: {question}\n\nAnswer (entity or yes/no, max 6 words):"
+        # E2G ("Evidence → minimal Answer"): one bounded reasoning step before the
+        # answer, grounded in the passages, with an exemplar that pins HotpotQA
+        # answer granularity. Targets the dominant failure buckets (2-hop synthesis
+        # + near-miss span/format), per arXiv:2401.05787 / 2212.10509. Kept bounded
+        # (still /no_think, no <think> explosion) to stay inside the TPM budget.
+        # Default OFF: Run 23 (n=64, tracecag_rapid) showed bounded E2G with /no_think
+        # kept REGRESSES EM 46.9%→39.1% (net −5 EM per-sample: 1 gain, 6 losses) —
+        # the model writes a post-hoc Evidence line without real reasoning and diverges
+        # to wrong entities on questions direct answering got right (Phil Spector→"the
+        # Teddy Bears", YG Entertainment→WINNER). The research-backed gain needs REAL
+        # Qwen3 thinking (remove /no_think, ~500+ reasoning tokens/call), which blows the
+        # 500K/day TPD across n=64×3-modes. Knob kept for a future quota-permitting test.
+        _use_e2g = _env_flag("TRACECAG_BENCHMARK_E2G", False)
+        _bench_max_tokens = _env_int("TRACECAG_BENCHMARK_MAX_TOKENS", 220 if _use_e2g else 96)
+        if _use_e2g:
+            system_prompt = (
+                _no_think_prefix +
+                "You are a precise multi-hop QA system. Read ALL passages, find the "
+                "supporting fact(s), and chain them across passages to reach the answer.\n"
+                "Then give the MINIMAL final answer copied in the gold style: a short "
+                "entity/phrase (1–6 words), 'yes', or 'no'. Use the exact surface form as "
+                "it appears in the passage; do NOT add titles, honorifics, given names, "
+                "dates, or parentheticals beyond what the question asks. If the context "
+                "does not contain the answer, output 'unknown'.\n"
+                "Respond in EXACTLY this format, nothing else:\n"
+                "Evidence: <one short supporting fact chaining the hops>\n"
+                "Answer: <minimal final answer>\n\n"
+                "Example:\n"
+                "Context:\n"
+                "[Doctor Strange (2016 film)] Doctor Strange is a 2016 Marvel film starring "
+                "Benedict Cumberbatch, directed by Scott Derrickson.\n"
+                "[Scott Derrickson] Scott Derrickson is an American director.\n"
+                "Question: What nationality is the director of the 2016 film starring "
+                "Benedict Cumberbatch as the title role?\n"
+                "Evidence: Doctor Strange (2016) stars Cumberbatch and was directed by Scott "
+                "Derrickson, who is American.\n"
+                "Answer: American"
+            )
+            user_prompt = f"Context:\n{truncated_context}\n\nQuestion: {question}"
+        else:
+            system_prompt = (
+                _no_think_prefix +
+                "You are a precise QA system for multi-hop reasoning benchmarks. "
+                "The context spans multiple passages — read ALL of them, identify key entities and facts, "
+                "then chain the evidence to reach the answer. "
+                "Output ONLY the minimal final answer: a short entity/phrase (1–6 words), 'yes', or 'no'. "
+                "Never explain, never add punctuation or preamble. "
+                "If genuinely unanswerable from the context, output exactly: unknown"
+            )
+            user_prompt = f"Context:\n{truncated_context}\n\nQuestion: {question}{_hint_block}\n\nAnswer (entity or yes/no, max 6 words):"
 
         try:
             import httpx
@@ -340,15 +752,18 @@ async def _generate_benchmark_qa_response(state: TraceCAGState, start_time: floa
                     break
 
                 if provider == "groq":
-                    from api.core.groq_key_pool import get_available_groq_key, record_groq_key_usage, get_groq_key_pool
+                    from api.core.groq_key_pool import get_available_groq_key, record_groq_key_usage, get_configured_key_count
                     groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
                     # Retry across all available keys — skip keys returning 401 (expired/invalid)
-                    _pool = get_groq_key_pool()
-                    _max_key_tries = _pool.count if _pool else 4
+                    # 5 retries (2s..32s, ~62s worst case): Run 19 showed Groq's qwen3-32b
+                    # over-capacity periods can outlast 3 retries (14s) for a sample.
+                    _max_503_retries = 5
+                    _max_key_tries = (get_configured_key_count() or 1) + _max_503_retries
                     _tried_groq_keys: set = set()
+                    _503_retry_count = 0
                     for _key_attempt in range(_max_key_tries):
                         groq_key = await get_available_groq_key(estimated_tokens=96)
-                        if not groq_key or groq_key in _tried_groq_keys:
+                        if not groq_key or (groq_key in _tried_groq_keys and _503_retry_count >= _max_503_retries):
                             break
                         _tried_groq_keys.add(groq_key)
                         try:
@@ -356,17 +771,29 @@ async def _generate_benchmark_qa_response(state: TraceCAGState, start_time: floa
                                 provider="groq",
                                 url="https://api.groq.com/openai/v1/chat/completions",
                                 headers={"Authorization": f"Bearer {groq_key}", "Content-Type": "application/json"},
-                                payload={"model": groq_model, "messages": messages, "max_tokens": 96, "temperature": 0.0},
+                                payload={"model": groq_model, "messages": messages, "max_tokens": _bench_max_tokens, "temperature": 0.0},
                                 httpx_module=httpx,
                                 timeout=30.0,
                             )
                             if resp is not None and resp.status_code == 200:
                                 data = resp.json()
-                                tokens = data.get("usage", {}).get("total_tokens", 96)
+                                tokens = data.get("usage", {}).get("total_tokens", _bench_max_tokens)
                                 await record_groq_key_usage(groq_key, tokens)
                                 _raw = data["choices"][0]["message"]["content"].strip()
                                 # Strip <think>…</think> blocks (Qwen3 thinking mode)
-                                response = re.sub(r"<think>.*?</think>\s*", "", _raw, flags=re.DOTALL).strip()
+                                _raw = re.sub(r"<think>.*?</think>\s*", "", _raw, flags=re.DOTALL).strip()
+                                # E2G: keep only the final "Answer:" line (drop the Evidence
+                                # reasoning so it never reaches the EM/F1 scorer). Fall back to
+                                # the last non-empty line if the model skipped the format.
+                                if _use_e2g:
+                                    _ans_lines = re.findall(r"(?im)^\s*(?:final\s+)?answer\s*:\s*(.+?)\s*$", _raw)
+                                    if _ans_lines:
+                                        response = _ans_lines[-1].strip()
+                                    else:
+                                        _nonempty = [ln.strip() for ln in _raw.splitlines() if ln.strip()]
+                                        response = (_nonempty[-1] if _nonempty else _raw).strip()
+                                else:
+                                    response = _raw
                                 model_used = f"groq/{groq_model}"
                                 break
                             elif resp is not None and resp.status_code == 401:
@@ -374,6 +801,19 @@ async def _generate_benchmark_qa_response(state: TraceCAGState, start_time: floa
                                     "[_generate_benchmark_qa_response] Groq key invalid (401), trying next key"
                                 )
                                 continue
+                            elif resp is not None and resp.status_code == 503 and _503_retry_count < _max_503_retries:
+                                # Transient "over capacity" — Groq's own error message asks for
+                                # exponential backoff; the old code gave up to extractive_fallback
+                                # on the very first occurrence instead of honoring that.
+                                _503_retry_count += 1
+                                _backoff = 2 ** _503_retry_count
+                                logger.warning(
+                                    "[_generate_benchmark_qa_response] Groq 503 over capacity, "
+                                    "backing off %ss (retry %d/%d)",
+                                    _backoff, _503_retry_count, _max_503_retries,
+                                )
+                                await asyncio.sleep(_backoff)
+                                continue
                             else:
                                 logger.warning(
                                     "[_generate_benchmark_qa_response] Groq returned %s: %s",
@@ -493,11 +933,17 @@ async def _generate_benchmark_qa_response(state: TraceCAGState, start_time: floa
 
     latency_ms = int((time.time() - start_time) * 1000)
     logger.info("[_generate_benchmark_qa_response] Generated QA response via %s in %dms", model_used, latency_ms)
+    retrieval_meta = dict(state.get("retrieval_meta") or {})
+    if "_ircot_meta" in locals() and _ircot_meta.get("evaluated"):
+        retrieval_meta["ircot"] = _ircot_meta
+    models_used = list(locals().get("auxiliary_models", []))
+    models_used.append(model_used)
     return {
         "tutor_response": response.strip(),
         "strategy": "benchmark_qa",
         "next_action": "continue",
         "overall_score": overall_score,
         "ttft_ms": latency_ms,
-        "models_used": [model_used],
+        "models_used": models_used,
+        "retrieval_meta": retrieval_meta,
     }
diff --git a/ai-service/api/services/trace_cag/benchmark/ranking.py b/ai-service/api/services/trace_cag/benchmark/ranking.py
index 49a6ce7f..3429aa33 100644
--- a/ai-service/api/services/trace_cag/benchmark/ranking.py
+++ b/ai-service/api/services/trace_cag/benchmark/ranking.py
@@ -16,6 +16,16 @@
 # Local copy of the decay constant (mirrors nodes_v2._RECENCY_LAMBDA).
 _RECENCY_LAMBDA = 0.01
 
+# tracecag_rapid bridge/graph weight. NOTE (2026-06-26, Run 22): raising this
+# from 0.18→0.80 was offline-validated to lift recall@5 79%→84% and
+# both-supporting@7 69%→78% with flat rank-1 precision — yet live it REGRESSED
+# end-to-end EM 46.9%→43.8% (recovered 0 of the 25% "gold dropped by ranking"
+# questions, flipped 2 clean wins via added distractors). Lesson: retrieval
+# recall is NOT the binding constraint here — the 32B reader's multi-hop
+# synthesis is — so more/higher-ranked evidence the reader can't use is
+# net-negative. Default stays 0.18 (the EM-best config); knob kept for research.
+_RAPID_GRAPH_WEIGHT = _env_float("TRACECAG_RAPID_GRAPH_WEIGHT", 0.18)
+
 
 # ── Text helpers ──────────────────────────────────────────────────────────────
 
@@ -217,27 +227,48 @@ def _select_diverse_multihop_evidence(
 
 # ── Graph helpers ─────────────────────────────────────────────────────────────
 
-def _build_candidate_graph(candidates: list[Dict[str, Any]]) -> dict[str, set[str]]:
+def _build_candidate_graph(candidates: list[Dict[str, Any]]) -> dict[str, dict[str, float]]:
+    """
+    Bridge-entity adjacency for multi-hop reasoning: edge A->B means A's body
+    text names the bridge entity that B's title covers (the standard HotpotQA
+    bridge pattern, where doc A mentions the entity whose own page B holds the
+    next-hop answer). Edge weight 1.0 = B's full title appears verbatim in A's
+    text (high-precision bridge mention); 0.4 = weaker token-overlap fallback
+    for titles that get paraphrased instead of quoted exactly.
+    """
+    title_norm_map = {
+        str(candidate["item_id"]): _normalize_benchmark_surface(
+            str(candidate.get("title") or candidate.get("item_id") or "")
+        )
+        for candidate in candidates
+    }
     title_token_map = {
         str(candidate["item_id"]): _title_tokens(str(candidate.get("title") or candidate.get("item_id") or ""))
         for candidate in candidates
     }
-    adjacency: dict[str, set[str]] = {str(candidate["item_id"]): set() for candidate in candidates}
+    adjacency: dict[str, dict[str, float]] = {str(candidate["item_id"]): {} for candidate in candidates}
 
     for candidate in candidates:
         source_id = str(candidate["item_id"])
+        source_text_norm = _normalize_benchmark_surface(str(candidate.get("text") or ""))
         source_text_tokens = set(_benchmark_tokens(str(candidate.get("text") or "")))
         for other in candidates:
             target_id = str(other["item_id"])
             if source_id == target_id:
                 continue
+
+            target_title_norm = title_norm_map.get(target_id, "")
+            if target_title_norm and len(target_title_norm) >= 4 and f" {target_title_norm} " in f" {source_text_norm} ":
+                adjacency[source_id][target_id] = 1.0
+                continue
+
             title_tokens = title_token_map.get(target_id, set())
             if not title_tokens:
                 continue
             overlap = len(source_text_tokens & title_tokens)
             threshold = 1 if len(title_tokens) <= 2 else 2
             if overlap >= threshold:
-                adjacency[source_id].add(target_id)
+                adjacency[source_id][target_id] = 0.4
     return adjacency
 
 
@@ -271,6 +302,7 @@ def _compute_evidence_budget(
     benchmark_mode: str,
     benchmark_candidates: bool,
     adaptive_profile: str = "",
+    benchmark_task: str = "",
 ) -> int:
     # Lazy import to avoid circular dependency at module load time.
     from api.services.trace_cag.benchmark.adaptive import _ADAPTIVE_PROFILES
@@ -280,8 +312,6 @@ def _compute_evidence_budget(
     complexity = _question_complexity_score(question)
     budget = base + max(0, complexity - 2)
 
-    benchmark_task = "multihop_qa" if "multihop" in (question or "").lower() else ""
-
     if retrieval_policy == "rapid":
         # Keep full evidence budget for multihop-style questions in rapid mode.
         if benchmark_task != "multihop_qa":
@@ -291,7 +321,7 @@ def _compute_evidence_budget(
         if config is not None:
             budget += int(config.evidence_budget_delta)
 
-    if benchmark_candidates and benchmark_mode == "trace-cag_adaptive":
+    if benchmark_candidates and benchmark_mode == "tracecag_adaptive":
         config = _ADAPTIVE_PROFILES.get(adaptive_profile or "balanced")
         if config is not None:
             budget = max(4, min(max_budget, budget + int(config.evidence_budget_delta)))
@@ -353,7 +383,7 @@ def _rank_benchmark_candidates(
 
     adjacency = _build_candidate_graph(candidates)
     degree_scores = {
-        item_id: (len(neighbors) / max(len(candidates) - 1, 1))
+        item_id: (sum(neighbors.values()) / max(len(candidates) - 1, 1))
         for item_id, neighbors in adjacency.items()
     }
     seed_ids = [
@@ -368,8 +398,9 @@ def _rank_benchmark_candidates(
             if seed_id == item_id:
                 seed_bridge = max(seed_bridge, base_scores.get(seed_id, 0.0))
                 continue
-            if item_id in adjacency.get(seed_id, set()) or seed_id in adjacency.get(item_id, set()):
-                seed_bridge = max(seed_bridge, base_scores.get(seed_id, 0.0))
+            edge_weight = adjacency.get(seed_id, {}).get(item_id) or adjacency.get(item_id, {}).get(seed_id)
+            if edge_weight:
+                seed_bridge = max(seed_bridge, base_scores.get(seed_id, 0.0) * edge_weight)
         graph_scores[item_id] = (0.7 * seed_bridge) + (0.3 * degree_scores.get(item_id, 0.0))
 
     memory_state = _normalize_score_map(base_scores)
@@ -378,9 +409,10 @@ def _rank_benchmark_candidates(
         for source_id, neighbors in adjacency.items():
             if not neighbors:
                 continue
-            shared = 0.85 * memory_state.get(source_id, 0.0) / len(neighbors)
-            for target_id in neighbors:
-                propagated[target_id] = propagated.get(target_id, 0.0) + shared
+            weight_total = sum(neighbors.values()) or 1.0
+            shared = 0.85 * memory_state.get(source_id, 0.0)
+            for target_id, edge_weight in neighbors.items():
+                propagated[target_id] = propagated.get(target_id, 0.0) + shared * (edge_weight / weight_total)
         memory_state = _normalize_score_map(propagated)
 
     scored_candidates: list[Dict[str, Any]] = []
@@ -406,16 +438,19 @@ def _rank_benchmark_candidates(
                     + (0.08 * query_coverage)
                     + (0.08 * anchor_coverage)
                 )
-            elif benchmark_mode == "trace-cag_rapid":
-                # Rebalance toward broader top-k coverage (R@1..R@5) over top-1 peaking.
+            elif benchmark_mode == "tracecag_rapid":
+                # Keep the full lexical base score (matches flat ranker's strength on
+                # single-hop docs) and add the bridge/graph signal on top instead of
+                # diluting base_score — diluting it previously made multi-hop bridge
+                # targets win at the cost of demoting strong direct matches.
                 final_score = (
-                    (0.34 * base_score)
-                    + (0.16 * graph_score)
-                    + (0.24 * memory_score)
-                    + (0.10 * query_coverage)
-                    + (0.08 * anchor_coverage)
-                    + (0.04 * anchor_title_exact)
-                    + (0.04 * title_token_recall)
+                    base_score
+                    + (_RAPID_GRAPH_WEIGHT * graph_score)
+                    + (0.06 * memory_score)
+                    + (0.06 * query_coverage)
+                    + (0.05 * anchor_coverage)
+                    + (0.03 * anchor_title_exact)
+                    + (0.03 * title_token_recall)
                 )
                 if title_phrase >= 0.9:
                     final_score += 0.04
@@ -423,7 +458,7 @@ def _rank_benchmark_candidates(
                     final_score += 0.03
                 else:
                     final_score += 0.01 * title_phrase
-            elif benchmark_mode == "trace-cag_adaptive":
+            elif benchmark_mode == "tracecag_adaptive":
                 profile = _ADAPTIVE_PROFILES.get(adaptive_profile or "balanced")
                 if profile is None:
                     profile = _ADAPTIVE_PROFILES["balanced"]
@@ -587,7 +622,7 @@ def _rank_with_online_ranker(
 
     # Keep graph/title heuristic dominant until online ranker has enough updates.
     mode = str(benchmark_mode or "").strip().lower()
-    if mode == "trace-cag_rapid":
+    if mode == "tracecag_rapid":
         snapshot = ranker.snapshot()
         updates = int(snapshot.get("updates", 0) or 0)
         warmup_updates = max(1, _env_int("TRACECAG_RANKER_WARMUP_UPDATES", 40))
diff --git a/ai-service/api/services/trace_cag/cache_utils.py b/ai-service/api/services/trace_cag/cache_utils.py
index a65202ac..588a4459 100644
--- a/ai-service/api/services/trace_cag/cache_utils.py
+++ b/ai-service/api/services/trace_cag/cache_utils.py
@@ -60,6 +60,11 @@ def _is_exact_reuse_match(fingerprint: CacheFingerprint, entry: CacheEntry) -> b
     if fingerprint.get("level") != cached_fingerprint.get("level"):
         return False
 
+    cur_lang = fingerprint.get("native_language")
+    cached_lang = cached_fingerprint.get("native_language")
+    if cur_lang and cached_lang and cur_lang != cached_lang:
+        return False
+
     current_intent = fingerprint.get("intent", "unknown")
     cached_intent = cached_fingerprint.get("intent", "unknown")
     if current_intent != "unknown" and cached_intent != "unknown" and current_intent != cached_intent:
@@ -83,10 +88,18 @@ def _compute_reuse_risk(
 
     ρ = clip[0,1]( w1·ΔI + w2·ΔC + w3·Δℓ + w4·Δprog + w5·s )
     """
+    # A cached response generated for a different native language can't be
+    # reused or patched — the hint/explanation text is in the wrong language
+    # regardless of how close the grammar/intent/level match is.
+    cached_fp = entry.get("fingerprint") or {}
+    cur_lang = fingerprint.get("native_language")
+    cached_lang = cached_fp.get("native_language")
+    if cur_lang and cached_lang and cur_lang != cached_lang:
+        return 1.0
+
     # Compare intents fingerprint-to-fingerprint: both sides are built with the
     # same pre-diagnosis extractor. execution_plan.intent is diagnosis-stage
     # vocabulary and would read as drift even for identical queries.
-    cached_fp = entry.get("fingerprint") or {}
     cur_intent = fingerprint.get("intent", "unknown")
     cached_intent = cached_fp.get("intent") or (entry.get("execution_plan") or {}).get("intent", "unknown")
     if cur_intent == "unknown" or cached_intent == "unknown":
@@ -145,6 +158,7 @@ def _build_fingerprint(state: TraceCAGState) -> CacheFingerprint:
         query_norm=state.get("user_input", "").strip().lower(),
         intent=_infer_intent_pre_diagnosis(state.get("user_input", "")),
         level=state.get("learner_profile", {}).get("level", "B1"),
+        native_language=state.get("learner_profile", {}).get("native_language", "Vietnamese"),
         root_concepts=_extract_lightweight_graph_concepts(state.get("user_input", "")),
         session_turn=len(state.get("conversation_history", [])),
     )
@@ -201,6 +215,7 @@ def _build_l1_request_signature(
         answer_target=_answer_target_hint(user_input),
         relation_hints=_relation_hints(user_input),
         evidence_hash="",
+        native_language=str(fingerprint.get("native_language") or ""),
     )
     hints = state_hints or {}
     return replace(
@@ -255,7 +270,8 @@ def _build_l1_candidate_signature(
         answer_target=_answer_target_hint(candidate_query),
         relation_hints=_relation_hints(candidate_query),
         evidence_hash=_evidence_dependency_hash(entry),
-        created_at=float(entry.get("created_at") or time.monotonic()),
+        native_language=str(candidate_fp.get("native_language") or ""),
+        created_at=float(entry.get("created_at") or time.time()),
         ttl=int(entry.get("ttl") or 3600),
     )
     return replace(
@@ -782,7 +798,10 @@ async def _write_cache_entry(
     )
 
     ttl = 3600 if errors else 1800
-    now = time.monotonic()
+    # Wall-clock, not monotonic: created_at is serialized into Redis and read
+    # back by other processes/hosts, where monotonic()'s reference point is
+    # undefined (Python docs) and only happens to align on a single host.
+    now = time.time()
 
     raw_bundle = [
         {"type": "kg", "content": c}
@@ -908,10 +927,12 @@ async def cache_gate_node(state: TraceCAGState) -> Dict[str, Any]:
     bucket = _build_graph_bucket(user_input, level, intent_hint, profile_epoch, conversation_history)
     l1_buckets = _build_l1_bucket_aliases(user_input, level, intent_hint, profile_epoch, conversation_history)
 
+    native_language = learner_profile.get("native_language", "Vietnamese")
     fingerprint = CacheFingerprint(
         query_norm=user_input.strip().lower(),
         intent=intent_hint,
         level=level,
+        native_language=native_language,
         root_concepts=_extract_lightweight_graph_concepts(user_input),
         session_turn=len(conversation_history),
     )
@@ -985,7 +1006,9 @@ def _with_gate_meta(
     best_rejection: tuple[float, tuple[str, ...]] | None = None
 
     # --- Try in-process cache ---
-    now = time.monotonic()
+    # Wall-clock (see _write_cache_entry): must compare against created_at
+    # values that may have been written by a different process/host via Redis.
+    now = time.time()
     entry = await _get_cache_entry(cache_key, level, now)
     if entry:
         if not _cache_entry_quality_ok_for_benchmark(entry, benchmark_task):
diff --git a/ai-service/api/services/trace_cag/generate.py b/ai-service/api/services/trace_cag/generate.py
new file mode 100644
index 00000000..be80f4e7
--- /dev/null
+++ b/ai-service/api/services/trace_cag/generate.py
@@ -0,0 +1,660 @@
+"""
+TraceCAG generate_node — grounded generation (LLM call with KG/retrieval context).
+
+Split out of nodes_v2.py (Phase 4 refactor) along with its prompt-building and
+token-streaming helpers, which the streaming chat endpoint also calls directly.
+"""
+
+import asyncio
+import json
+import logging
+import os
+import time
+from typing import Any, AsyncGenerator, Dict, List
+
+from api.services.trace_cag.state import TraceCAGState
+from api.services.trace_cag.evaluation_agent import EvaluationAgent
+from api.services.document_intelligence import get_doc_intel_service
+from api.services.llama_kv_service import get_local_llama_kv_service
+
+from api.services.trace_cag.env_helpers import _env_flag
+from api.services.trace_cag.provider_state import _provider_is_disabled
+from api.services.trace_cag.llm_client import _get_httpx_client, _throttled_post_json
+from api.services.trace_cag.cache_utils import _write_cache_entry
+
+from api.services.trace_cag.benchmark.ranking import _update_ranker_from_generation
+from api.services.trace_cag.benchmark.qa_generation import (
+    _generate_extractive_fallback_response,
+    _generate_benchmark_qa_response,
+)
+
+logger = logging.getLogger(__name__)
+
+_LOCAL_LLAMA_CORE_SYSTEM_PROMPT = (
+    "You are Lexi, an expert English tutor. "
+    "Provide grounded, concise and actionable feedback. "
+    "If evidence is weak, state uncertainty explicitly."
+)
+
+
+def _compute_difficulty_ramp(session_turn: int, overall_score: float) -> str:
+    """
+    PCC difficulty signal based on session progress + learner performance.
+
+    Returns: 'gentle' | 'standard' | 'challenging'
+      - gentle:     first 3 turns or score < 0.50
+      - standard:   turns 3-8 or score 0.50-0.70
+      - challenging: turns 8+ with score >= 0.70
+    """
+    if session_turn < 3 or overall_score < 0.50:
+        return "gentle"
+    if session_turn < 8 or overall_score < 0.70:
+        return "standard"
+    return "challenging"
+
+
+def build_generation_prompt(
+    state: Dict[str, Any],
+) -> tuple[str, List[Dict[str, Any]]]:
+    """Extract (system_prompt, messages) from raw pipeline state.
+
+    Used by the streaming endpoint so it can call the LLM with streaming
+    enabled after the rest of the pipeline (KG, diagnosis, retrieval) has
+    prepared the context.
+    """
+    errors = state.get("diagnosis_errors", [])
+    intent = state.get("diagnosis_intent", "correct")
+    level = (state.get("learner_profile") or {}).get("level", "B1")
+    user_input = str(state.get("user_input") or "")
+    context = str(state.get("retrieved_context") or "")
+    vietnamese_hint = state.get("vietnamese_hint")
+    session_turn = len(state.get("conversation_history") or [])
+    prev_overall = state.get("overall_score", 0.5)
+    fluency_score = state.get("fluency_score", 0.8)
+    error_count = len(errors)
+
+    difficulty = _compute_difficulty_ramp(session_turn, prev_overall)
+
+    if intent == "explain" and fluency_score > 0.7:
+        strategy = "socratic"
+    elif error_count == 0:
+        strategy = "praise"
+    elif error_count <= 2:
+        strategy = "feedback"
+    else:
+        strategy = "scaffold"
+
+    system_prompt = (
+        "You are Lexi 🦜, a cheerful, witty parrot who is an expert English tutor.\n"
+        "You speak in a warm, encouraging tone — like a fun game character guiding an adventure.\n"
+        "Keep responses concise (2-4 sentences). Use the knowledge context provided.\n"
+        "Gently correct mistakes with encouraging context.\n"
+        f"The learner's current CEFR level is: {level}\n"
+        f"Difficulty setting for this turn: {difficulty}\n"
+    )
+    if context:
+        system_prompt += f"\n--- Knowledge Graph Context ---\n{context}\n"
+
+    if strategy == "socratic":
+        system_prompt += (
+            "\nStrategy: SOCRATIC. Guide through short questions, don't reveal answer.\n"
+        )
+        if errors:
+            hints = "\n".join(
+                f"- '{e.get('span','')}' → '{e.get('correction','')}'"
+                for e in errors[:3]
+            )
+            system_prompt += f"\n--- Errors (hints only) ---\n{hints}\n"
+    elif errors:
+        errs_text = "\n".join(
+            f"- '{e.get('span','')}' → '{e.get('correction','')}' ({e.get('explanation','')})"
+            for e in errors[:3]
+        )
+        system_prompt += f"\n--- Errors Found ---\n{errs_text}\n"
+        system_prompt += f"Strategy: {strategy}. Weave corrections naturally.\n"
+    else:
+        system_prompt += "\nNo errors found — praise the learner's effort!\n"
+
+    if vietnamese_hint:
+        system_prompt += f"\n--- Vietnamese Hint ---\n{vietnamese_hint}\n"
+
+    messages: List[Dict[str, Any]] = [{"role": "system", "content": system_prompt}]
+    for msg in (state.get("conversation_history") or [])[-12:]:
+        role = msg.get("role")
+        content = msg.get("content", "")
+        if role and content:
+            messages.append({"role": role, "content": content})
+        elif msg.get("user"):
+            messages.append({"role": "user", "content": msg["user"]})
+            if msg.get("ai"):
+                messages.append({"role": "assistant", "content": msg["ai"]})
+    messages.append({"role": "user", "content": user_input})
+
+    return system_prompt, messages
+
+
+async def stream_llm_tokens(
+    *,
+    system_prompt: str,
+    messages: List[Dict[str, Any]],
+    user_input: str,
+) -> "AsyncGenerator[str, None]":
+    """Stream tokens from Groq (preferred) then Gemini as fallback.
+
+    Yields raw text deltas as they arrive from the provider.
+    Falls back silently to Gemini if Groq is unavailable or rate-limited.
+    """
+
+    async def _try_groq() -> "AsyncGenerator[str, None]":
+        from api.core.groq_key_pool import get_available_groq_key, record_groq_key_usage
+
+        groq_key = await get_available_groq_key(estimated_tokens=512)
+        groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
+        if not groq_key or _provider_is_disabled("groq"):
+            return
+
+        # Disable Qwen3 thinking mode to prevent thinking tokens consuming max_tokens budget.
+        groq_messages = messages
+        if "qwen" in groq_model.lower():
+            groq_messages = list(messages)
+            for i, msg in enumerate(groq_messages):
+                if msg.get("role") == "user":
+                    groq_messages[i] = {**msg, "content": f"/no_think\n{msg['content']}"}
+                    break
+
+        client = _get_httpx_client("groq")
+        tokens_yielded = 0
+        try:
+            async with client.stream(
+                "POST",
+                "https://api.groq.com/openai/v1/chat/completions",
+                headers={
+                    "Authorization": f"Bearer {groq_key}",
+                    "Content-Type": "application/json",
+                },
+                json={
+                    "model": groq_model,
+                    "messages": groq_messages,
+                    "max_tokens": 512,
+                    "temperature": 0.7,
+                    "stream": True,
+                },
+                timeout=25.0,
+            ) as resp:
+                if resp.status_code != 200:
+                    logger.warning("[stream_llm_tokens] Groq status %d", resp.status_code)
+                    return
+                async for line in resp.aiter_lines():
+                    if not line.startswith("data: "):
+                        continue
+                    data = line[6:]
+                    if data.strip() == "[DONE]":
+                        break
+                    try:
+                        obj = json.loads(data)
+                        delta = obj["choices"][0]["delta"].get("content") or ""
+                        if delta:
+                            tokens_yielded += len(delta.split())
+                            yield delta
+                    except Exception as _exc:
+                        logger.debug("[generate] ignored: %s", _exc)
+                        pass
+            await record_groq_key_usage(groq_key, max(50, tokens_yielded + 50))
+        except Exception as exc:
+            logger.warning("[stream_llm_tokens] Groq stream error: %s", exc)
+
+    async def _try_gemini() -> "AsyncGenerator[str, None]":
+        gemini_key = os.getenv("GEMINI_API_KEY", "")
+        if not gemini_key or _provider_is_disabled("gemini"):
+            return
+
+        url = (
+            "https://generativelanguage.googleapis.com/v1beta/models/"
+            f"gemini-2.0-flash:streamGenerateContent?key={gemini_key}&alt=sse"
+        )
+        request_body = {
+            "contents": [{"role": "user", "parts": [{"text": user_input}]}],
+            "systemInstruction": {"parts": [{"text": system_prompt}]},
+        }
+        client = _get_httpx_client("gemini")
+        try:
+            async with client.stream(
+                "POST", url, json=request_body, timeout=25.0
+            ) as resp:
+                if resp.status_code != 200:
+                    logger.warning("[stream_llm_tokens] Gemini status %d", resp.status_code)
+                    return
+                async for line in resp.aiter_lines():
+                    if not line.startswith("data: "):
+                        continue
+                    data = line[6:]
+                    try:
+                        obj = json.loads(data)
+                        text = (
+                            obj.get("candidates", [{}])[0]
+                            .get("content", {})
+                            .get("parts", [{}])[0]
+                            .get("text", "")
+                        )
+                        if text:
+                            yield text
+                    except Exception as _exc:
+                        logger.debug("[generate] ignored: %s", _exc)
+                        pass
+        except Exception as exc:
+            logger.warning("[stream_llm_tokens] Gemini stream error: %s", exc)
+
+    # Try Groq first; if it yields nothing, fall back to Gemini
+    got_tokens = False
+    async for token in _try_groq():
+        got_tokens = True
+        yield token
+
+    if not got_tokens:
+        async for token in _try_gemini():
+            yield token
+
+
+async def generate_node(state: TraceCAGState) -> Dict[str, Any]:
+    """
+    Generate the tutor response using LLM grounded in KG evidence.
+
+    This node calls the LLM fallback chain (Groq → Gemini → Ollama)
+    with the Lexi persona, KG context, and diagnosis data injected
+    into the system prompt. This is the SINGLE place where LLM
+    generation happens — callers should NOT make a separate LLM call.
+    """
+    # When the streaming endpoint handles generation externally, skip this node.
+    if state.get("generation_policy") == "skip":
+        return {}
+
+    logger.info("[generate_node] Generating grounded tutor response...")
+    start_time = time.time()
+
+    errors = state.get("diagnosis_errors", [])
+    intent = state.get("diagnosis_intent", "correct")
+    level = state.get("learner_profile", {}).get("level", "B1")
+    user_input = state.get("user_input", "")
+    context = state.get("retrieved_context", "")
+    jit_soft_graph = str(state.get("jit_soft_graph") or "").strip()
+    vietnamese_hint = state.get("vietnamese_hint")
+    benchmark_task = state.get("benchmark_task")
+
+    if benchmark_task in {"multihop_qa", "retrieval_qa"}:
+        return await _generate_benchmark_qa_response(state, start_time)
+
+    # Determine strategy (paper Eq. strategy)
+    error_count = len(errors)
+    fluency_score = state.get("fluency_score", 0.8)
+
+    if intent == "explain" and fluency_score > 0.7:
+        strategy = "socratic"
+    elif error_count == 0:
+        strategy = "praise"
+    elif error_count <= 2:
+        strategy = "feedback"
+    else:
+        strategy = "scaffold"
+
+    generation_policy = state.get("generation_policy", "auto")
+    if generation_policy == "template":
+        logger.warning("[generate_node] generation_policy='template' is deprecated; using extractive policy")
+        generation_policy = "extractive"
+
+    if generation_policy == "extractive":
+        response = _generate_extractive_fallback_response(errors, strategy, user_input, context)
+        model_used = "extractive_policy"
+
+        if strategy == "socratic":
+            next_action = "ask"
+        elif error_count == 0:
+            next_action = "continue"
+        elif error_count <= 2:
+            next_action = "hint"
+        else:
+            next_action = "correct"
+
+        grammar_score = state.get("grammar_score", 0.8)
+        fluency_score = state.get("fluency_score", 0.8)
+        vocab_level = state.get("vocabulary_level", "B1")
+        overall_score = EvaluationAgent.compute_overall_score(grammar_score, fluency_score, vocab_level)
+
+        _update_ranker_from_generation(
+            question=user_input,
+            response=response,
+            retrieval_trace=list(state.get("retrieval_trace") or []),
+        )
+
+        if state.get("cache_policy", "on") == "on":
+            try:
+                await _write_cache_entry(state, response, strategy, errors, overall_score, context, model_used=model_used)
+            except Exception as e:
+                logger.debug(f"[generate_node] Cache write failed: {e}")
+
+        latency_ms = int((time.time() - start_time) * 1000)
+
+        return {
+            "tutor_response": response,
+            "strategy": strategy,
+            "next_action": next_action,
+            "overall_score": overall_score,
+            "ttft_ms": latency_ms,
+            "models_used": [model_used],
+        }
+
+    # Build system prompt with Lexi persona + grounded context
+    session_turn = len(state.get("conversation_history", []))
+    prev_overall = state.get("overall_score", 0.5)
+    difficulty = _compute_difficulty_ramp(session_turn, prev_overall)
+
+    system_prompt = (
+        "You are Lexi 🦜, a cheerful, witty parrot who is an expert English tutor.\n"
+        "You speak in a warm, encouraging tone — like a fun game character guiding an adventure.\n"
+        "Keep responses concise (2-4 sentences). Use the knowledge context provided.\n"
+        "Gently correct mistakes with encouraging context.\n"
+        f"The learner's current CEFR level is: {level}\n"
+        f"Difficulty setting for this turn: {difficulty}\n"
+    )
+
+    if context:
+        system_prompt += f"\n--- Knowledge Graph Context ---\n{context}\n"
+
+    if strategy == "socratic":
+        system_prompt += (
+            "\nStrategy: SOCRATIC. The learner asked for an explanation and is fairly fluent.\n"
+            "Guide them through a chain of short questions so they discover the answer themselves.\n"
+            "Do NOT give the answer directly — instead ask 1-2 leading questions.\n"
+        )
+        if errors:
+            errors_text = "\n".join([
+                f"- '{e.get('span','')}' → '{e.get('correction','')}' ({e.get('explanation','')})"
+                for e in errors[:3]
+            ])
+            system_prompt += f"\n--- Errors Found (use as hints, don't reveal directly) ---\n{errors_text}\n"
+    elif errors:
+        errors_text = "\n".join([
+            f"- '{e.get('span','')}' → '{e.get('correction','')}' ({e.get('explanation','')})"
+            for e in errors[:3]
+        ])
+        system_prompt += f"\n--- Errors Found ---\n{errors_text}\n"
+        system_prompt += f"Strategy: {strategy}. Weave corrections naturally into your response.\n"
+    else:
+        system_prompt += "\nNo errors found — praise the learner's effort!\n"
+
+    if vietnamese_hint:
+        system_prompt += f"\n--- Vietnamese Hint (for reference) ---\n{vietnamese_hint}\n"
+
+    response = ""
+    model_used = "llm_unavailable"
+
+    local_llama_enabled = _env_flag("TRACECAG_ENABLE_LOCAL_LLAMA_KV", False)
+    if local_llama_enabled and not response:
+        try:
+            local_llama = get_local_llama_kv_service()
+            local_result = await local_llama.generate(
+                session_id=str(state.get("session_id") or "default"),
+                core_system_prompt=_LOCAL_LLAMA_CORE_SYSTEM_PROMPT,
+                dynamic_system_prompt=system_prompt,
+                user_query=user_input,
+                soft_graph="" if "[JIT_SOFT_GRAPH]" in context else jit_soft_graph,
+            )
+            if local_result and str(local_result.get("text") or "").strip():
+                response = str(local_result.get("text") or "").strip()
+                model_used = str(local_result.get("model") or "llama_cpp_kv")
+        except Exception as e:
+            logger.warning(f"[generate_node] Local llama KV path failed, fallback to provider chain: {e}")
+
+    # Call LLM via fallback chain (Groq → Gemini → Ollama)
+    if not response:
+        response = ""
+        model_used = "llm_unavailable"
+
+    try:
+        import httpx
+
+        messages = [{"role": "system", "content": system_prompt}]
+
+        # Inject conversation history (last 6 turns = up to 12 messages)
+        history = state.get("conversation_history", [])
+        for msg in history[-12:]:
+            role = msg.get("role")
+            content = msg.get("content", "")
+            if role and content:
+                # Standard {"role": "user"/"assistant", "content": "..."} format
+                messages.append({"role": role, "content": content})
+            elif msg.get("user"):
+                # ConversationCache {"user": "...", "ai": "..."} format
+                messages.append({"role": "user", "content": msg["user"]})
+                if msg.get("ai"):
+                    messages.append({"role": "assistant", "content": msg["ai"]})
+
+        messages.append({"role": "user", "content": user_input})
+
+        if not response:
+            # Race Groq and Gemini concurrently; first successful response wins.
+            # Ollama is kept as last-resort with a tighter 15s timeout.
+            import asyncio as _asyncio
+            from api.core.groq_key_pool import get_available_groq_key, record_groq_key_usage
+
+            groq_key = await get_available_groq_key(estimated_tokens=512)
+            groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
+            gemini_key = os.getenv("GEMINI_API_KEY", "")
+
+            # Disable Qwen3 thinking to keep token budget for actual response.
+            _groq_messages = list(messages)
+            if "qwen" in groq_model.lower():
+                for i, msg in enumerate(_groq_messages):
+                    if msg.get("role") == "user":
+                        _groq_messages[i] = {**msg, "content": f"/no_think\n{msg['content']}"}
+                        break
+
+            async def _try_groq():
+                if not groq_key:
+                    return None, None
+                try:
+                    resp = await _throttled_post_json(
+                        provider="groq",
+                        url="https://api.groq.com/openai/v1/chat/completions",
+                        headers={"Authorization": f"Bearer {groq_key}", "Content-Type": "application/json"},
+                        payload={"model": groq_model, "messages": _groq_messages, "max_tokens": 512, "temperature": 0.7},
+                        httpx_module=httpx,
+                        timeout=20.0,
+                    )
+                    if resp is not None and resp.status_code == 200:
+                        data = resp.json()
+                        tokens = data.get("usage", {}).get("total_tokens", 500)
+                        await record_groq_key_usage(groq_key, tokens)
+                        return data["choices"][0]["message"]["content"], f"groq/{groq_model}"
+                except Exception as e:
+                    logger.warning(f"[generate_node] Groq failed: {e}")
+                return None, None
+
+            async def _try_gemini():
+                if not gemini_key:
+                    return None, None
+                try:
+                    gemini_contents = [{"role": "user", "parts": [{"text": user_input}]}]
+                    url = f"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key={gemini_key}"
+                    request_body = {
+                        "contents": gemini_contents,
+                        "systemInstruction": {"parts": [{"text": system_prompt}]},
+                    }
+                    resp = await _throttled_post_json(
+                        provider="gemini",
+                        url=url,
+                        payload=request_body,
+                        httpx_module=httpx,
+                        timeout=20.0,
+                    )
+                    if resp is not None and resp.status_code == 200:
+                        candidates = resp.json().get("candidates", [])
+                        if candidates:
+                            return candidates[0]["content"]["parts"][0]["text"], "gemini-2.0-flash"
+                except Exception as e:
+                    logger.warning(f"[generate_node] Gemini failed: {e}")
+                return None, None
+
+            # Launch both concurrently; pick first non-None result.
+            tasks = [_asyncio.ensure_future(_try_groq()), _asyncio.ensure_future(_try_gemini())]
+            done, pending = await _asyncio.wait(tasks, return_when=_asyncio.FIRST_COMPLETED)
+            for task in done:
+                try:
+                    _text, _model = task.result()
+                    if _text:
+                        response = _text
+                        model_used = _model
+                        break
+                except Exception as _exc:
+                    logger.debug("[generate] ignored: %s", _exc)
+                    pass
+            # If winner found, cancel the loser immediately.
+            if response:
+                for p in pending:
+                    p.cancel()
+            else:
+                # Wait for the second one too before falling back to Ollama.
+                if pending:
+                    done2, _ = await _asyncio.wait(pending, timeout=15.0)
+                    for task in done2:
+                        try:
+                            _text, _model = task.result()
+                            if _text:
+                                response = _text
+                                model_used = _model
+                                break
+                        except Exception as _exc:
+                            logger.debug("[generate] ignored: %s", _exc)
+                            pass
+
+            # Ollama — last resort, tight 15s timeout.
+            if not response:
+                from api.core.config import settings
+                ollama_url = settings.OLLAMA_BASE_URL
+                ollama_model = os.getenv("OLLAMA_MODEL", "lexilingo-qwen3-1.7b")
+                try:
+                    resp = await _throttled_post_json(
+                        provider="ollama",
+                        url=f"{ollama_url}/api/chat",
+                        payload={
+                            "model": ollama_model,
+                            "messages": messages,
+                            "stream": False,
+                            "options": {"num_predict": 256, "temperature": 0.7},
+                        },
+                        httpx_module=httpx,
+                        timeout=15.0,
+                        max_retries=1,
+                    )
+                    if resp is not None and resp.status_code == 200:
+                        response = resp.json().get("message", {}).get("content", "")
+                        model_used = f"ollama/{ollama_model}"
+                except Exception as e:
+                    logger.warning(f"[generate_node] Ollama failed: {e}")
+
+    except Exception as e:
+        logger.error(f"[generate_node] LLM chain error: {e}")
+
+    # 4. Deterministic extractive fallback
+    if not response:
+        response = _generate_extractive_fallback_response(errors, strategy, user_input, context)
+        model_used = "extractive_fallback"
+
+    # Determine next action
+    if strategy == "socratic":
+        next_action = "ask"
+    elif error_count == 0:
+        next_action = "continue"
+    elif error_count <= 2:
+        next_action = "hint"
+    else:
+        next_action = "correct"
+
+    # Calculate overall score
+    grammar_score = state.get("grammar_score", 0.8)
+    fluency_score = state.get("fluency_score", 0.8)
+    vocab_level = state.get("vocabulary_level", "B1")
+    overall_score = EvaluationAgent.compute_overall_score(grammar_score, fluency_score, vocab_level)
+
+    _update_ranker_from_generation(
+        question=user_input,
+        response=response,
+        retrieval_trace=list(state.get("retrieval_trace") or []),
+    )
+
+    # Generate personalized practice exercises via ContentAutoGenerator (cag_service)
+    action_plan = []
+    if errors or intent == "practice":
+        try:
+            from api.services.cag_service import ContentAutoGenerator
+            cag_gen = ContentAutoGenerator()
+            err_types = [err.get("type", "grammar") for err in errors if isinstance(err, dict)]
+            if not err_types:
+                err_types = ["grammar"]
+
+            first_err_type = err_types[0] if errors else "vocabulary"
+            if "vocab" in first_err_type.lower() or intent == "practice":
+                vocab_ex = cag_gen.generate_vocabulary_exercise(
+                    level=level,
+                    error_patterns=err_types if errors else None,
+                    count=3
+                )
+                action_plan.append({
+                    "action": "practice",
+                    "type": "vocabulary",
+                    "concept": vocab_ex.get("topic", ""),
+                    "count": len(vocab_ex.get("words", [])),
+                    "exercise": vocab_ex
+                })
+            else:
+                grammar_drill = cag_gen.generate_grammar_drill(
+                    level=level,
+                    error_patterns=err_types,
+                    count=3
+                )
+                action_plan.append({
+                    "action": "practice",
+                    "type": "grammar",
+                    "concept": grammar_drill.get("grammar_point", ""),
+                    "count": len(grammar_drill.get("exercises", [])),
+                    "exercise": grammar_drill
+                })
+        except Exception as cag_err:
+            logger.warning(f"[generate_node] Failed to generate CAG practice: {cag_err}")
+
+    state["action_plan"] = action_plan
+
+    # Store response in Redis cache for future hits
+    if state.get("cache_policy", "on") == "on":
+        try:
+            # ── Tiered Cache Management (L0/L1 Promotion) ─────────────
+            # Nếu thông tin từ L2 được sử dụng, kiểm tra thăng hạng
+            doc_service = get_doc_intel_service()
+            trace = state.get("retrieval_trace", [])
+            is_l2_used = any(t.get("item_id", "").startswith("ext_") for t in trace[:3])
+
+            if is_l2_used:
+                for t in trace[:3]:
+                    if t.get("item_id", "").startswith("ext_"):
+                        chunk_id = str(t.get("item_id") or "").replace("ext_", "")
+                        if doc_service.should_promote_to_cache(chunk_id):
+                            logger.info(f"[cache_promotion] Chunk {chunk_id[:8]} promoted to L1 cache")
+                            await _write_cache_entry(state, response, strategy, errors, overall_score, context)
+                            break
+            else:
+                # Mặc định cache cho các luồng KG/Rules để tối ưu tốc độ
+                await _write_cache_entry(state, response, strategy, errors, overall_score, context)
+        except Exception as e:
+            logger.debug(f"[generate_node] Cache write failed: {e}")
+
+    latency_ms = int((time.time() - start_time) * 1000)
+    logger.info(f"[generate_node] Generated response via {model_used} in {latency_ms}ms")
+
+    return {
+        "tutor_response": response,
+        "strategy": strategy,
+        "next_action": next_action,
+        "overall_score": overall_score,
+        "action_plan": action_plan,
+        "ttft_ms": latency_ms,
+        "models_used": [model_used],
+    }
diff --git a/ai-service/api/services/trace_cag/l1_state_cache.py b/ai-service/api/services/trace_cag/l1_state_cache.py
index 55bcf769..a6170fae 100644
--- a/ai-service/api/services/trace_cag/l1_state_cache.py
+++ b/ai-service/api/services/trace_cag/l1_state_cache.py
@@ -25,6 +25,7 @@ class L1Request:
     answer_target: str = ""
     relation_hints: set[str] = field(default_factory=set)
     evidence_hash: str = ""
+    native_language: str = ""
 
 
 @dataclass(frozen=True)
@@ -42,6 +43,7 @@ class L1Candidate:
     answer_target: str = ""
     relation_hints: set[str] = field(default_factory=set)
     evidence_hash: str = ""
+    native_language: str = ""
     created_at: float = 0.0
     ttl: int = 3600
 
@@ -88,11 +90,16 @@ def decide_l1_reuse(
     Risk scoring then separates exact safe reuse from near-hit patching.
     """
 
-    current_time = time.monotonic() if now is None else now
+    # Wall-clock: candidate.created_at is read back from Redis and may have
+    # been written by a different process/host (monotonic()'s reference point
+    # is undefined across processes per the stdlib docs).
+    current_time = time.time() if now is None else now
     reasons: list[str] = []
 
     if request.level != candidate.level:
         reasons.append("level_mismatch")
+    if not _empty_or_equal(request.native_language, candidate.native_language):
+        reasons.append("native_language_mismatch")
     if request.profile_epoch != candidate.profile_epoch:
         reasons.append("profile_epoch_mismatch")
     if not _empty_or_equal(request.intent, candidate.intent):
diff --git a/ai-service/api/services/trace_cag/nodes_v2.py b/ai-service/api/services/trace_cag/nodes_v2.py
index 2cb93b7e..3d545d3e 100644
--- a/ai-service/api/services/trace_cag/nodes_v2.py
+++ b/ai-service/api/services/trace_cag/nodes_v2.py
@@ -17,30 +17,20 @@
 import re
 import json
 import time
-import math
-from typing import AsyncGenerator, Dict, Any, List, Optional
+from typing import Dict, Any, List, Optional
 
 from api.services.trace_cag.state import TraceCAGState, DiagnosisError
 from api.services.trace_cag.evaluation_agent import EvaluationAgent
-from api.services.trace_cag.retrieval_ranker import get_retrieval_ranker
-from api.services.document_intelligence import get_doc_intel_service
 from api.services.jit_graph_service import get_jit_graph_service
-from api.services.llama_kv_service import get_local_llama_kv_service
 
-from api.services.trace_cag.env_helpers import _env_flag, _env_float, _env_int, _clip01
+from api.services.trace_cag.env_helpers import _env_flag
 from api.services.trace_cag.provider_state import _provider_is_disabled
 
 # LLM client — httpx pooling and rate-limit throttling
-from api.services.trace_cag.llm_client import _get_httpx_client, _throttled_post_json
-
-# KG query cache utilities
-from api.services.trace_cag.kg_utils import (
-    _KG_QUERY_CACHE, _kg_cache_key, _kg_cache_get, _kg_cache_set,
-    _pack_kg_nodes_for_context,
-)
+from api.services.trace_cag.llm_client import _throttled_post_json
 
 # PCC cache R/W helpers used by the generation path
-from api.services.trace_cag.cache_utils import _detect_native_request, _write_cache_entry
+from api.services.trace_cag.cache_utils import _detect_native_request
 
 # Façade re-exports: graph.py imports cache_gate_node from this module, and the
 # cache-gate tests reach these helpers through the nodes_v2 namespace.
@@ -52,35 +42,23 @@
     _profile_epoch,
 )
 
-from api.services.trace_cag.benchmark.adaptive import (
-    _adaptive_mode_enabled, _choose_adaptive_profile,
-)
-from api.services.trace_cag.benchmark.ranking import (
-    _select_diverse_multihop_evidence, _compute_evidence_budget,
-    _rank_benchmark_candidates, _ranker_enabled, _rank_with_online_ranker,
-    _build_benchmark_candidates, _update_ranker_from_generation,
-)
-from api.services.trace_cag.benchmark.qa_generation import (
-    _generate_extractive_fallback_response,
-    _generate_benchmark_qa_response,
+# retrieve_node / generate_node live in their own modules (Phase 4 split) —
+# re-exported here so existing `from nodes_v2 import ...` call sites keep working.
+from api.services.trace_cag.retrieve import retrieve_node  # noqa: F401
+from api.services.trace_cag.generate import (  # noqa: F401
+    build_generation_prompt,
+    stream_llm_tokens,
+    generate_node,
 )
 
 logger = logging.getLogger(__name__)
 
-_LOCAL_LLAMA_CORE_SYSTEM_PROMPT = (
-    "You are Lexi, an expert English tutor. "
-    "Provide grounded, concise and actionable feedback. "
-    "If evidence is weak, state uncertainty explicitly."
-)
-
-
 
 # ============================================================
 # MODEL GATEWAY INTEGRATION
 # ============================================================
 
 _gateway_instance = None
-_retrieval_v3_instance = None
 
 
 async def get_gateway():
@@ -94,16 +72,6 @@ async def get_gateway():
     return _gateway_instance
 
 
-async def _get_retrieval_v3():
-    """Lazy singleton for RetrievalServiceV3 (centrality + community ranking)."""
-    global _retrieval_v3_instance
-    if _retrieval_v3_instance is None:
-        from api.services.kg_service_v3 import get_kg_service
-        from api.services.retrieval_service_v3 import RetrievalServiceV3
-        _retrieval_v3_instance = RetrievalServiceV3(get_kg_service())
-    return _retrieval_v3_instance
-
-
 # ============================================================
 # NODE 1: INPUT NODE
 # ============================================================
@@ -131,6 +99,9 @@ async def input_node(state: TraceCAGState) -> Dict[str, Any]:
         
         try:
             import asyncio as _asyncio
+            if RedisClient._benchmark_redis_disabled():
+                raise RuntimeError("Redis disabled for benchmark")
+
             redis_client = await RedisClient.get_instance()
 
             user_id = state.get("user_id")
@@ -163,7 +134,10 @@ async def _get_history():
             conversation_history = fetched_history or []
 
         except Exception as e:
-            logger.warning(f"Redis unavailable: {e}")
+            if RedisClient._benchmark_redis_disabled():
+                logger.debug(f"Redis unavailable: {e}")
+            else:
+                logger.warning(f"Redis unavailable: {e}")
     
         latency_ms = int((time.time() - start_time) * 1000)
         
@@ -661,1104 +635,6 @@ async def _jit_graph_extract_node(state: TraceCAGState) -> Dict[str, Any]:
             "jit_graph_meta": {"enabled": False, "error": str(exc)},
         }
 
-_FUSION_ALPHA = 0.5   # KG structural relevance weight
-_FUSION_BETA = 0.3    # Vector similarity weight
-_FUSION_GAMMA = 0.2   # Recency bonus weight
-_RECENCY_LAMBDA = 0.01  # Decay rate for recency bonus
-
-
-# ============================================================
-# PCC: PROGRESSIVE COMPLEXITY CONTROL
-# ============================================================
-
-def _compute_difficulty_ramp(session_turn: int, overall_score: float) -> str:
-    """
-    PCC difficulty signal based on session progress + learner performance.
-
-    Returns: 'gentle' | 'standard' | 'challenging'
-      - gentle:     first 3 turns or score < 0.50
-      - standard:   turns 3-8 or score 0.50-0.70
-      - challenging: turns 8+ with score >= 0.70
-    """
-    if session_turn < 3 or overall_score < 0.50:
-        return "gentle"
-    if session_turn < 8 or overall_score < 0.70:
-        return "standard"
-    return "challenging"
-
-
-def _fusion_score(
-    kg_depth: int,
-    vec_sim: float,
-    last_used_turns_ago: int,
-) -> float:
-    """
-    Compute fusion score for a retrieved evidence item (paper Eq. 8).
-
-    s_kg  = 1 / (1 + depth)         — inverse hop distance
-    s_vec = cosine similarity        — from MiniLM
-    s_rec = exp(-λ · Δt)            — recency bonus
-    """
-    s_kg = 1.0 / (1.0 + kg_depth)
-    s_vec = vec_sim
-    s_rec = math.exp(-_RECENCY_LAMBDA * last_used_turns_ago)
-    return _FUSION_ALPHA * s_kg + _FUSION_BETA * s_vec + _FUSION_GAMMA * s_rec
-
-
-
-# ============================================================
-# NODE 4: BUDGETED HYBRID RETRIEVAL (paper Alg. 5)
-# ============================================================
-
-async def retrieve_node(state: TraceCAGState) -> Dict[str, Any]:
-    """
-    Budgeted hybrid retrieval with fusion scoring (paper Alg. 5).
-
-    Stage 1: Graph-local evidence (cheap) — KG concepts + diagnosis
-    Stage 2: Optional vector evidence (budgeted) — MiniLM similarity
-    Fusion:  score(e) = α·s_kg + β·s_vec + γ·s_rec  (Eq. 8)
-    """
-    logger.info("[retrieve_node] Budgeted hybrid retrieval...")
-    start_time = time.time()
-    retrieve_start = time.monotonic()
-
-    kg_budget_ms = max(0.0, _env_float("TRACECAG_RETRIEVE_BUDGET_KG_MS", 120.0))
-    vector_budget_ms = max(0.0, _env_float("TRACECAG_RETRIEVE_BUDGET_VECTOR_MS", 80.0))
-    fusion_budget_ms = max(0.0, _env_float("TRACECAG_RETRIEVE_BUDGET_FUSION_MS", 40.0))
-    total_budget_ms = kg_budget_ms + vector_budget_ms + fusion_budget_ms
-
-    def _elapsed_ms() -> float:
-        return (time.monotonic() - retrieve_start) * 1000.0
-
-    budget_exhausted = False
-
-    retrieval_policy = state.get("retrieval_policy", "full")
-    benchmark_context = (state.get("benchmark_context") or "").strip()
-    benchmark_task = state.get("benchmark_task") or ""
-    benchmark_metadata = state.get("benchmark_metadata") or {}
-    benchmark_ranker = str(benchmark_metadata.get("_benchmark_ranker") or "graph").strip().lower()
-    benchmark_mode = str(benchmark_metadata.get("_benchmark_mode") or "").strip().lower()
-    user_input = state.get("user_input", "")
-    adaptive_profile = str(state.get("adaptive_profile") or "").strip().lower()
-    adaptive_features = dict(state.get("adaptive_features") or {})
-    adaptive_controller = dict(state.get("adaptive_controller") or {})
-
-    if _adaptive_mode_enabled(state, benchmark_mode) and not adaptive_profile:
-        adaptive_choice = _choose_adaptive_profile(
-            state=state,
-            user_input=user_input,
-            benchmark_task=benchmark_task,
-            benchmark_mode=benchmark_mode,
-            benchmark_metadata=benchmark_metadata,
-        )
-        adaptive_profile = str(adaptive_choice.get("profile") or "balanced")
-        adaptive_features = dict(adaptive_choice.get("features") or {})
-        adaptive_controller = {
-            **dict(adaptive_choice.get("controller") or {}),
-            "explore": bool(adaptive_choice.get("explore", False)),
-            "objective_map": adaptive_choice.get("objective_map", {}),
-            "tau_reuse": adaptive_choice.get("tau_reuse"),
-            "tau_patch": adaptive_choice.get("tau_patch"),
-            "support_floor": adaptive_choice.get("support_floor"),
-            "evidence_budget_delta": adaptive_choice.get("evidence_budget_delta"),
-        }
-
-    kg_concepts = state.get("kg_seed_concepts", [])
-    kg_expanded = state.get("kg_expanded_nodes", [])
-    session_turn = len(state.get("conversation_history", []))
-    benchmark_candidates, relevant_ids = _build_benchmark_candidates(state)
-
-    # ── Stage 1: Graph-local evidence (cheap) ────────────────────────
-    # Each evidence item: {"text": ..., "kg_depth": ..., "vec_sim": ..., "turns_ago": ...}
-    evidence_items: List[Dict[str, Any]] = []
-
-    for concept_id in state.get("diagnosis_root_causes", []):
-        evidence_items.append({
-            "text": f"Grammar concept: {concept_id}",
-            "kg_depth": 0,
-            "vec_sim": 0.0,
-            "turns_ago": 0,
-        })
-
-    for node in kg_expanded:
-        depth = node.get("depth", 1) if isinstance(node, dict) else 1
-        evidence_items.append({
-            "text": f"Related: {node.get('id', '')} ({node.get('relation', '')})",
-            "kg_depth": depth,
-            "vec_sim": 0.0,
-            "turns_ago": session_turn,
-        })
-
-    # Query KG with top-K node retrieval and bounded context packing to control prompt size.
-    if not benchmark_candidates and not benchmark_context:
-        try:
-            from api.services.kg_service_v3 import get_kg_service
-
-            learner_level = state.get("learner_profile", {}).get("level", "B1")
-            top_k = max(1, _env_int("TRACECAG_KG_TOPK", 8))
-            token_budget = max(32, _env_int("TRACECAG_KG_CONTEXT_TOKEN_BUDGET", 160))
-
-            cache_key = _kg_cache_key(user_input, learner_level, top_k)
-            queried_nodes = _kg_cache_get(cache_key)
-            if queried_nodes is None:
-                kg = get_kg_service()
-                queried_nodes = kg.query_concepts(user_input, learner_level=learner_level, top_k=top_k)
-                _kg_cache_set(cache_key, queried_nodes)
-
-            packed_nodes = _pack_kg_nodes_for_context(queried_nodes, token_budget)
-            for node in packed_nodes:
-                title = str(node.get("title") or node.get("id") or "")
-                keywords = str(node.get("keywords") or "")
-                score = float(node.get("score") or 0.0)
-                evidence_items.append({
-                    "item_id": str(node.get("id") or title),
-                    "title": title,
-                    "text": f"Concept: {title}. Keywords: {keywords}",
-                    "kg_depth": 1,
-                    "vec_sim": max(0.0, min(1.0, score)),
-                    "turns_ago": session_turn,
-                })
-        except Exception as kg_exc:
-            logger.warning(f"[retrieve_node] KG top-K query skipped: {kg_exc}")
-
-    for error in state.get("diagnosis_errors", [])[:3]:
-        evidence_items.append({
-            "text": f"Error: '{error.get('span', '')}' → '{error.get('correction', '')}' — {error.get('explanation', '')}",
-            "kg_depth": 0,
-            "vec_sim": 0.0,
-            "turns_ago": 0,
-        })
-
-    if benchmark_candidates:
-        evidence_items = []
-        ranked_candidates = _rank_benchmark_candidates(
-            user_input,
-            benchmark_candidates,
-            benchmark_ranker,
-            benchmark_mode,
-            adaptive_profile,
-        )
-        for candidate in ranked_candidates:
-            final_score = float(candidate.get("fusion_score", candidate.get("vec_sim", 0.0)))
-            evidence_items.append({
-                "item_id": candidate["item_id"],
-                "title": candidate["title"],
-                "text": candidate["text"],
-                "kg_depth": candidate["kg_depth"],
-                "vec_sim": final_score,
-                "turns_ago": candidate["turns_ago"],
-                "graph_score": float(candidate.get("graph_score") or 0.0),
-                "memory_score": float(candidate.get("memory_score") or 0.0),
-                "precomputed_score": final_score,
-                "is_relevant": candidate["item_id"] in relevant_ids,
-            })
-    elif benchmark_context:
-        evidence_items.insert(0, {
-            "item_id": "benchmark_context",
-            "title": "benchmark_context",
-            "text": benchmark_context,
-            "kg_depth": 0,
-            "vec_sim": 1.0,
-            "turns_ago": 0,
-            "is_relevant": True,
-        })
-
-    # ── Stage 2: RetrievalServiceV3 (centrality + community ranking) ─────
-    vector_hits = []
-    if not benchmark_candidates and _elapsed_ms() <= (kg_budget_ms + vector_budget_ms):
-        errors = state.get("diagnosis_errors", [])
-        confidence = float(state.get("diagnosis_confidence", 0.0) or 0.0)
-        is_multihop_task = benchmark_task == "multihop_qa"
-
-        do_vector_search = True
-        max_hits = 5
-
-        if retrieval_policy == "rapid":
-            if len(errors) == 0 and confidence >= 0.85 and not is_multihop_task:
-                do_vector_search = False
-            elif len(errors) <= 2 and confidence >= 0.72:
-                max_hits = 3
-
-        if do_vector_search and _elapsed_ms() <= (kg_budget_ms + vector_budget_ms):
-            # ── Primary: RetrievalServiceV3 (centrality + community diversity) ──
-            try:
-                from api.models.v3_schemas import V3PipelineContext
-
-                retrieval_v3 = await _get_retrieval_v3()
-                ctx = V3PipelineContext(
-                    user_input=user_input,
-                    session_id=state.get("session_id", ""),
-                    user_id=state.get("user_id"),
-                )
-                seed_nodes = [
-                    c if isinstance(c, str) else c.get("id", "")
-                    for c in kg_concepts[:5]
-                ]
-                bundle = await retrieval_v3.retrieve(user_input, seed_nodes, ctx)
-
-                for hit in bundle.vector_hits[:max_hits]:
-                    snippet = getattr(hit, "snippet", hit.id)
-                    vector_hits.append({"text": snippet, "score": hit.score})
-                    evidence_items.append({
-                        "item_id": hit.id,
-                        "title": snippet,
-                        "text": f"Concept ({hit.id}): {snippet}",
-                        "kg_depth": 2,
-                        "vec_sim": hit.score,
-                        "turns_ago": session_turn,
-                    })
-
-                logger.info(
-                    f"[retrieve_node] RetrievalServiceV3: {len(vector_hits)} hits "
-                    f"(centrality+community ranked)"
-                )
-
-            except Exception as e:
-                logger.warning(
-                    f"[retrieve_node] RetrievalServiceV3 unavailable, "
-                    f"falling back to MiniLM gateway: {e}"
-                )
-                # ── Fallback: MiniLM gateway ──────────────────────────────────
-                try:
-                    from api.services.model_gateway import get_gateway
-
-                    gateway = await get_gateway()
-                    max_expanded = 10
-                    threshold = 0.3
-
-                    if retrieval_policy == "rapid" and len(errors) <= 2 and confidence >= 0.7:
-                        max_expanded = 5
-                        threshold = 0.35
-
-                    candidate_labels = []
-                    for c in kg_concepts:
-                        if isinstance(c, dict):
-                            candidate_labels.append(c.get("id", "") + " " + c.get("label", ""))
-                        else:
-                            candidate_labels.append(str(c))
-                    for node in kg_expanded[:max_expanded]:
-                        label = node.get("id", "") + " " + node.get("label", node.get("relation", ""))
-                        if label.strip() and label not in candidate_labels:
-                            candidate_labels.append(label)
-
-                    if candidate_labels:
-                        result = await gateway.invoke(
-                            "minilm", "invoke",
-                            {"task": "similarity", "query": user_input, "candidates": candidate_labels},
-                        )
-                        if result.get("success"):
-                            sim_results = result.get("data", {}).get("results", [])
-                            for r in sim_results:
-                                if r["score"] >= threshold:
-                                    vector_hits.append({"text": r["text"], "score": r["score"]})
-                                    evidence_items.append({
-                                        "text": f"Semantic match: {r['text']}",
-                                        "kg_depth": 2,
-                                        "vec_sim": r["score"],
-                                        "turns_ago": session_turn,
-                                    })
-
-                            vector_hits = vector_hits[:max_hits]
-                            logger.info(f"[retrieve_node] MiniLM fallback: {len(vector_hits)} hits")
-                except Exception as e2:
-                    logger.warning(f"[retrieve_node] Vector search fully skipped: {e2}")
-    elif not benchmark_candidates:
-        budget_exhausted = True
-
-    # ── Stage 3: L2 External Knowledge (Selective Retrieval) ─────────
-    # Phân tích xem có nên ép buộc tìm kiếm bên ngoài không (Proactive Dynamic Retrieval)
-    force_external = False
-    dynamic_patterns = [
-        r"\bhôm (qua|nay|kia)\b", r"\bmới (đây|nhất)\b", r"\bvừa mới\b",
-        r"\brecently\b", r"\byesterday\b", r"\btoday\b", r"\blatest\b", r"\bcurrent\b",
-        r"\bdo you know\b", r"\bnghe nói\b", r"\bbạn có biết\b", r"\bnews\b", r"\btin tức\b"
-    ]
-    if any(re.search(p, user_input, re.IGNORECASE) for p in dynamic_patterns):
-        force_external = True
-        logger.info("[retrieve_node] Dynamic intent detected. Forcing L2 Search.")
-
-    # Kích hoạt L2 nếu (thiếu dữ liệu) HOẶC (phát hiện intent cần tin tức thực tế)
-    if (len(evidence_items) < 3 or force_external) and not benchmark_candidates:
-        try:
-            doc_service = get_doc_intel_service()
-            # Nếu force_external, ta có thể điều chỉnh query để search hiệu quả hơn
-            search_query = user_input
-            if force_external and len(user_input) < 100:
-                # Bổ sung ngữ cảnh để search Tavily tốt hơn
-                search_query = f"latest information about {user_input}"
-                
-            external_hits = await asyncio.wait_for(
-                doc_service.query_l2(search_query), timeout=5.0
-            )
-            for hit in external_hits:
-                # Tránh trùng lặp nếu đã có trong evidence_items
-                if any(e.get("chunk_id") == hit["id"] for e in evidence_items):
-                    continue
-                    
-                evidence_items.append({
-                    "item_id": f"ext_{hit['id']}",
-                    "title": "External Knowledge",
-                    "text": f"Context: {hit['content']}",
-                    "kg_depth": 3, # Tầng sâu hơn KG
-                    "vec_sim": hit["score"],
-                    "turns_ago": session_turn,
-                    "is_external": True,
-                    "chunk_id": hit["id"]
-                })
-            if external_hits:
-                logger.info(f"[retrieve_node] L2 Context injected: {len(external_hits)} chunks")
-        except Exception as e3:
-            logger.warning(f"[retrieve_node] L2 retrieval failed: {e3}")
-
-    # ── Fusion scoring and ranking ───────────────────────────────────
-    if _elapsed_ms() <= total_budget_ms:
-        for item in evidence_items:
-            if benchmark_candidates and "precomputed_score" in item:
-                item["fusion_score"] = float(item.get("precomputed_score") or 0.0)
-            else:
-                item["fusion_score"] = _fusion_score(
-                    kg_depth=item["kg_depth"],
-                    vec_sim=item["vec_sim"],
-                    last_used_turns_ago=item["turns_ago"],
-                )
-    else:
-        budget_exhausted = True
-        for item in evidence_items:
-            if "fusion_score" not in item:
-                item["fusion_score"] = float(item.get("vec_sim") or 0.0)
-
-    evidence_items = _rank_with_online_ranker(
-        question=user_input,
-        evidence_items=evidence_items,
-        allow_exploration=_adaptive_mode_enabled(state, benchmark_mode),
-        benchmark_mode=benchmark_mode,
-    )
-    evidence_budget = _compute_evidence_budget(
-        question=user_input,
-        retrieval_policy=retrieval_policy,
-        benchmark_mode=benchmark_mode,
-        benchmark_candidates=bool(benchmark_candidates),
-        adaptive_profile=adaptive_profile,
-    )
-    if benchmark_candidates and benchmark_task in {"multihop_qa", "retrieval_qa"}:
-        top_evidence = _select_diverse_multihop_evidence(
-            items=evidence_items,
-            question=user_input,
-            budget=evidence_budget,
-        )
-    else:
-        top_evidence = evidence_items[:evidence_budget]
-    retrieval_trace = [
-        {
-            "item_id": str(item.get("item_id") or item.get("title") or f"item_{idx}"),
-            "title": str(item.get("title") or item.get("item_id") or ""),
-            "text": str(item.get("text") or ""),
-            "rank": idx + 1,
-            "score": float(item.get("fusion_score") or 0.0),
-            "is_relevant": bool(item.get("is_relevant") or False),
-        }
-        for idx, item in enumerate(top_evidence)
-    ]
-
-    if benchmark_candidates:
-        context_parts = []
-        for item in top_evidence:
-            title = str(item.get("title") or "").strip()
-            text = str(item.get("text") or "").strip()
-            context_parts.append(f"[{title}] {text}" if title else text)
-        retrieved_context = "\n".join(part for part in context_parts if part).strip()
-    elif benchmark_context and benchmark_task in {"multihop_qa", "retrieval_qa"}:
-        retrieved_context = benchmark_context
-    else:
-        context_parts = [item["text"] for item in top_evidence]
-        retrieved_context = "\n".join(context_parts) if context_parts else ""
-
-    jit_soft_graph = str(state.get("jit_soft_graph") or "").strip()
-    jit_graph_meta = dict(state.get("jit_graph_meta") or {})
-    if jit_soft_graph:
-        retrieved_context = (
-            f"[JIT_SOFT_GRAPH]\n{jit_soft_graph}\n\n"
-            f"{retrieved_context}".strip()
-        )
-
-    latency_ms = int((time.time() - start_time) * 1000)
-    logger.info(
-        f"[retrieve_node] {len(evidence_items)} candidates → top {len(top_evidence)} via fusion scoring"
-        f" (mode={benchmark_mode or 'default'}, ranker={benchmark_ranker}, latency={latency_ms}ms)"
-    )
-
-    ranker_snapshot = get_retrieval_ranker().snapshot() if _ranker_enabled() else {}
-    graph_update = dict(state.get("graph_update") or {})
-
-    return {
-        "vector_hits": vector_hits,
-        "retrieved_context": retrieved_context,
-        "jit_soft_graph": jit_soft_graph or None,
-        "jit_graph_meta": jit_graph_meta,
-        "retrieval_trace": retrieval_trace,
-        "adaptive_profile": adaptive_profile or None,
-        "adaptive_features": adaptive_features,
-        "adaptive_controller": adaptive_controller,
-        "retrieval_meta": {
-            "budget": {
-                "kg_ms": kg_budget_ms,
-                "vector_ms": vector_budget_ms,
-                "fusion_ms": fusion_budget_ms,
-                "total_ms": total_budget_ms,
-                "elapsed_ms": _elapsed_ms(),
-                "exhausted": budget_exhausted,
-            },
-            "fusion": {
-                "alpha": _FUSION_ALPHA,
-                "beta": _FUSION_BETA,
-                "gamma": _FUSION_GAMMA,
-                "recency_lambda": _RECENCY_LAMBDA,
-            },
-            "kg_topk": {
-                "top_k": max(1, _env_int("TRACECAG_KG_TOPK", 8)),
-                "context_token_budget": max(32, _env_int("TRACECAG_KG_CONTEXT_TOKEN_BUDGET", 160)),
-                "query_cache_size": len(_KG_QUERY_CACHE),
-            },
-            "jit_graph": jit_graph_meta,
-            "graph_update": {
-                "latency_ms": int(graph_update.get("latency_ms") or 0),
-                "nodes_added": int(graph_update.get("nodes_added") or 0),
-                "edges_added": int(graph_update.get("edges_added") or 0),
-            },
-            "mode": benchmark_mode or "default",
-            "ranker": benchmark_ranker,
-            "learned_ranker": {
-                "enabled": _ranker_enabled(),
-                "blend": _clip01(_env_float("TRACECAG_RANKER_BLEND", 0.42)),
-                "snapshot": ranker_snapshot,
-            },
-            "adaptive": {
-                "profile": adaptive_profile or None,
-                "features": adaptive_features,
-                "controller": adaptive_controller,
-            },
-        },
-        "models_used": ["retrieval_fusion"] + (["minilm"] if vector_hits else []),
-    }
-
-
-# ============================================================
-# STREAMING HELPERS: Build prompt + stream tokens from LLM
-# ============================================================
-
-def build_generation_prompt(
-    state: Dict[str, Any],
-) -> tuple[str, List[Dict[str, Any]]]:
-    """Extract (system_prompt, messages) from raw pipeline state.
-
-    Used by the streaming endpoint so it can call the LLM with streaming
-    enabled after the rest of the pipeline (KG, diagnosis, retrieval) has
-    prepared the context.
-    """
-    errors = state.get("diagnosis_errors", [])
-    intent = state.get("diagnosis_intent", "correct")
-    level = (state.get("learner_profile") or {}).get("level", "B1")
-    user_input = str(state.get("user_input") or "")
-    context = str(state.get("retrieved_context") or "")
-    vietnamese_hint = state.get("vietnamese_hint")
-    session_turn = len(state.get("conversation_history") or [])
-    prev_overall = state.get("overall_score", 0.5)
-    fluency_score = state.get("fluency_score", 0.8)
-    error_count = len(errors)
-
-    difficulty = _compute_difficulty_ramp(session_turn, prev_overall)
-
-    if intent == "explain" and fluency_score > 0.7:
-        strategy = "socratic"
-    elif error_count == 0:
-        strategy = "praise"
-    elif error_count <= 2:
-        strategy = "feedback"
-    else:
-        strategy = "scaffold"
-
-    system_prompt = (
-        "You are Lexi 🦜, a cheerful, witty parrot who is an expert English tutor.\n"
-        "You speak in a warm, encouraging tone — like a fun game character guiding an adventure.\n"
-        "Keep responses concise (2-4 sentences). Use the knowledge context provided.\n"
-        "Gently correct mistakes with encouraging context.\n"
-        f"The learner's current CEFR level is: {level}\n"
-        f"Difficulty setting for this turn: {difficulty}\n"
-    )
-    if context:
-        system_prompt += f"\n--- Knowledge Graph Context ---\n{context}\n"
-
-    if strategy == "socratic":
-        system_prompt += (
-            "\nStrategy: SOCRATIC. Guide through short questions, don't reveal answer.\n"
-        )
-        if errors:
-            hints = "\n".join(
-                f"- '{e.get('span','')}' → '{e.get('correction','')}'"
-                for e in errors[:3]
-            )
-            system_prompt += f"\n--- Errors (hints only) ---\n{hints}\n"
-    elif errors:
-        errs_text = "\n".join(
-            f"- '{e.get('span','')}' → '{e.get('correction','')}' ({e.get('explanation','')})"
-            for e in errors[:3]
-        )
-        system_prompt += f"\n--- Errors Found ---\n{errs_text}\n"
-        system_prompt += f"Strategy: {strategy}. Weave corrections naturally.\n"
-    else:
-        system_prompt += "\nNo errors found — praise the learner's effort!\n"
-
-    if vietnamese_hint:
-        system_prompt += f"\n--- Vietnamese Hint ---\n{vietnamese_hint}\n"
-
-    messages: List[Dict[str, Any]] = [{"role": "system", "content": system_prompt}]
-    for msg in (state.get("conversation_history") or [])[-12:]:
-        role = msg.get("role")
-        content = msg.get("content", "")
-        if role and content:
-            messages.append({"role": role, "content": content})
-        elif msg.get("user"):
-            messages.append({"role": "user", "content": msg["user"]})
-            if msg.get("ai"):
-                messages.append({"role": "assistant", "content": msg["ai"]})
-    messages.append({"role": "user", "content": user_input})
-
-    return system_prompt, messages
-
-
-async def stream_llm_tokens(
-    *,
-    system_prompt: str,
-    messages: List[Dict[str, Any]],
-    user_input: str,
-) -> "AsyncGenerator[str, None]":
-    """Stream tokens from Groq (preferred) then Gemini as fallback.
-
-    Yields raw text deltas as they arrive from the provider.
-    Falls back silently to Gemini if Groq is unavailable or rate-limited.
-    """
-
-    async def _try_groq() -> "AsyncGenerator[str, None]":
-        from api.core.groq_key_pool import get_available_groq_key, record_groq_key_usage
-
-        groq_key = await get_available_groq_key(estimated_tokens=512)
-        groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
-        if not groq_key or _provider_is_disabled("groq"):
-            return
-
-        # Disable Qwen3 thinking mode to prevent thinking tokens consuming max_tokens budget.
-        groq_messages = messages
-        if "qwen" in groq_model.lower():
-            groq_messages = list(messages)
-            for i, msg in enumerate(groq_messages):
-                if msg.get("role") == "user":
-                    groq_messages[i] = {**msg, "content": f"/no_think\n{msg['content']}"}
-                    break
-
-        client = _get_httpx_client("groq")
-        tokens_yielded = 0
-        try:
-            async with client.stream(
-                "POST",
-                "https://api.groq.com/openai/v1/chat/completions",
-                headers={
-                    "Authorization": f"Bearer {groq_key}",
-                    "Content-Type": "application/json",
-                },
-                json={
-                    "model": groq_model,
-                    "messages": groq_messages,
-                    "max_tokens": 512,
-                    "temperature": 0.7,
-                    "stream": True,
-                },
-                timeout=25.0,
-            ) as resp:
-                if resp.status_code != 200:
-                    logger.warning("[stream_llm_tokens] Groq status %d", resp.status_code)
-                    return
-                async for line in resp.aiter_lines():
-                    if not line.startswith("data: "):
-                        continue
-                    data = line[6:]
-                    if data.strip() == "[DONE]":
-                        break
-                    try:
-                        obj = json.loads(data)
-                        delta = obj["choices"][0]["delta"].get("content") or ""
-                        if delta:
-                            tokens_yielded += len(delta.split())
-                            yield delta
-                    except Exception as _exc:
-                        logger.debug("[nodes_v2] ignored: %s", _exc)
-                        pass
-            await record_groq_key_usage(groq_key, max(50, tokens_yielded + 50))
-        except Exception as exc:
-            logger.warning("[stream_llm_tokens] Groq stream error: %s", exc)
-
-    async def _try_gemini() -> "AsyncGenerator[str, None]":
-        gemini_key = os.getenv("GEMINI_API_KEY", "")
-        if not gemini_key or _provider_is_disabled("gemini"):
-            return
-
-        url = (
-            "https://generativelanguage.googleapis.com/v1beta/models/"
-            f"gemini-2.0-flash:streamGenerateContent?key={gemini_key}&alt=sse"
-        )
-        request_body = {
-            "contents": [{"role": "user", "parts": [{"text": user_input}]}],
-            "systemInstruction": {"parts": [{"text": system_prompt}]},
-        }
-        client = _get_httpx_client("gemini")
-        try:
-            async with client.stream(
-                "POST", url, json=request_body, timeout=25.0
-            ) as resp:
-                if resp.status_code != 200:
-                    logger.warning("[stream_llm_tokens] Gemini status %d", resp.status_code)
-                    return
-                async for line in resp.aiter_lines():
-                    if not line.startswith("data: "):
-                        continue
-                    data = line[6:]
-                    try:
-                        obj = json.loads(data)
-                        text = (
-                            obj.get("candidates", [{}])[0]
-                            .get("content", {})
-                            .get("parts", [{}])[0]
-                            .get("text", "")
-                        )
-                        if text:
-                            yield text
-                    except Exception as _exc:
-                        logger.debug("[nodes_v2] ignored: %s", _exc)
-                        pass
-        except Exception as exc:
-            logger.warning("[stream_llm_tokens] Gemini stream error: %s", exc)
-
-    # Try Groq first; if it yields nothing, fall back to Gemini
-    got_tokens = False
-    async for token in _try_groq():
-        got_tokens = True
-        yield token
-
-    if not got_tokens:
-        async for token in _try_gemini():
-            yield token
-
-
-# ============================================================
-# NODE 5: GROUNDED GENERATION (LLM call with context)
-# ============================================================
-
-async def generate_node(state: TraceCAGState) -> Dict[str, Any]:
-    """
-    Generate the tutor response using LLM grounded in KG evidence.
-    
-    This node calls the LLM fallback chain (Groq → Gemini → Ollama)
-    with the Lexi persona, KG context, and diagnosis data injected
-    into the system prompt. This is the SINGLE place where LLM
-    generation happens — callers should NOT make a separate LLM call.
-    """
-    # When the streaming endpoint handles generation externally, skip this node.
-    if state.get("generation_policy") == "skip":
-        return {}
-
-    logger.info("[generate_node] Generating grounded tutor response...")
-    start_time = time.time()
-
-    errors = state.get("diagnosis_errors", [])
-    intent = state.get("diagnosis_intent", "correct")
-    level = state.get("learner_profile", {}).get("level", "B1")
-    user_input = state.get("user_input", "")
-    context = state.get("retrieved_context", "")
-    jit_soft_graph = str(state.get("jit_soft_graph") or "").strip()
-    vietnamese_hint = state.get("vietnamese_hint")
-    benchmark_task = state.get("benchmark_task")
-
-    if benchmark_task in {"multihop_qa", "retrieval_qa"}:
-        return await _generate_benchmark_qa_response(state, start_time)
-    
-    # Determine strategy (paper Eq. strategy)
-    error_count = len(errors)
-    fluency_score = state.get("fluency_score", 0.8)
-
-    if intent == "explain" and fluency_score > 0.7:
-        strategy = "socratic"
-    elif error_count == 0:
-        strategy = "praise"
-    elif error_count <= 2:
-        strategy = "feedback"
-    else:
-        strategy = "scaffold"
-
-    generation_policy = state.get("generation_policy", "auto")
-    if generation_policy == "template":
-        logger.warning("[generate_node] generation_policy='template' is deprecated; using extractive policy")
-        generation_policy = "extractive"
-
-    if generation_policy == "extractive":
-        response = _generate_extractive_fallback_response(errors, strategy, user_input, context)
-        model_used = "extractive_policy"
-
-        if strategy == "socratic":
-            next_action = "ask"
-        elif error_count == 0:
-            next_action = "continue"
-        elif error_count <= 2:
-            next_action = "hint"
-        else:
-            next_action = "correct"
-
-        grammar_score = state.get("grammar_score", 0.8)
-        fluency_score = state.get("fluency_score", 0.8)
-        vocab_level = state.get("vocabulary_level", "B1")
-        overall_score = EvaluationAgent.compute_overall_score(grammar_score, fluency_score, vocab_level)
-
-        _update_ranker_from_generation(
-            question=user_input,
-            response=response,
-            retrieval_trace=list(state.get("retrieval_trace") or []),
-        )
-
-        if state.get("cache_policy", "on") == "on":
-            try:
-                await _write_cache_entry(state, response, strategy, errors, overall_score, context, model_used=model_used)
-            except Exception as e:
-                logger.debug(f"[generate_node] Cache write failed: {e}")
-
-        latency_ms = int((time.time() - start_time) * 1000)
-
-        return {
-            "tutor_response": response,
-            "strategy": strategy,
-            "next_action": next_action,
-            "overall_score": overall_score,
-            "ttft_ms": latency_ms,
-            "models_used": [model_used],
-        }
-    
-    # Build system prompt with Lexi persona + grounded context
-    session_turn = len(state.get("conversation_history", []))
-    prev_overall = state.get("overall_score", 0.5)
-    difficulty = _compute_difficulty_ramp(session_turn, prev_overall)
-
-    system_prompt = (
-        "You are Lexi 🦜, a cheerful, witty parrot who is an expert English tutor.\n"
-        "You speak in a warm, encouraging tone — like a fun game character guiding an adventure.\n"
-        "Keep responses concise (2-4 sentences). Use the knowledge context provided.\n"
-        "Gently correct mistakes with encouraging context.\n"
-        f"The learner's current CEFR level is: {level}\n"
-        f"Difficulty setting for this turn: {difficulty}\n"
-    )
-    
-    if context:
-        system_prompt += f"\n--- Knowledge Graph Context ---\n{context}\n"
-    
-    if strategy == "socratic":
-        system_prompt += (
-            "\nStrategy: SOCRATIC. The learner asked for an explanation and is fairly fluent.\n"
-            "Guide them through a chain of short questions so they discover the answer themselves.\n"
-            "Do NOT give the answer directly — instead ask 1-2 leading questions.\n"
-        )
-        if errors:
-            errors_text = "\n".join([
-                f"- '{e.get('span','')}' → '{e.get('correction','')}' ({e.get('explanation','')})"
-                for e in errors[:3]
-            ])
-            system_prompt += f"\n--- Errors Found (use as hints, don't reveal directly) ---\n{errors_text}\n"
-    elif errors:
-        errors_text = "\n".join([
-            f"- '{e.get('span','')}' → '{e.get('correction','')}' ({e.get('explanation','')})"
-            for e in errors[:3]
-        ])
-        system_prompt += f"\n--- Errors Found ---\n{errors_text}\n"
-        system_prompt += f"Strategy: {strategy}. Weave corrections naturally into your response.\n"
-    else:
-        system_prompt += "\nNo errors found — praise the learner's effort!\n"
-    
-    if vietnamese_hint:
-        system_prompt += f"\n--- Vietnamese Hint (for reference) ---\n{vietnamese_hint}\n"
-
-    response = ""
-    model_used = "llm_unavailable"
-
-    local_llama_enabled = _env_flag("TRACECAG_ENABLE_LOCAL_LLAMA_KV", False)
-    if local_llama_enabled and not response:
-        try:
-            local_llama = get_local_llama_kv_service()
-            local_result = await local_llama.generate(
-                session_id=str(state.get("session_id") or "default"),
-                core_system_prompt=_LOCAL_LLAMA_CORE_SYSTEM_PROMPT,
-                dynamic_system_prompt=system_prompt,
-                user_query=user_input,
-                soft_graph="" if "[JIT_SOFT_GRAPH]" in context else jit_soft_graph,
-            )
-            if local_result and str(local_result.get("text") or "").strip():
-                response = str(local_result.get("text") or "").strip()
-                model_used = str(local_result.get("model") or "llama_cpp_kv")
-        except Exception as e:
-            logger.warning(f"[generate_node] Local llama KV path failed, fallback to provider chain: {e}")
-    
-    # Call LLM via fallback chain (Groq → Gemini → Ollama)
-    if not response:
-        response = ""
-        model_used = "llm_unavailable"
-    
-    try:
-        import httpx
-
-        messages = [{"role": "system", "content": system_prompt}]
-
-        # Inject conversation history (last 6 turns = up to 12 messages)
-        history = state.get("conversation_history", [])
-        for msg in history[-12:]:
-            role = msg.get("role")
-            content = msg.get("content", "")
-            if role and content:
-                # Standard {"role": "user"/"assistant", "content": "..."} format
-                messages.append({"role": role, "content": content})
-            elif msg.get("user"):
-                # ConversationCache {"user": "...", "ai": "..."} format
-                messages.append({"role": "user", "content": msg["user"]})
-                if msg.get("ai"):
-                    messages.append({"role": "assistant", "content": msg["ai"]})
-
-        messages.append({"role": "user", "content": user_input})
-        
-        if not response:
-            # Race Groq and Gemini concurrently; first successful response wins.
-            # Ollama is kept as last-resort with a tighter 15s timeout.
-            import asyncio as _asyncio
-            from api.core.groq_key_pool import get_available_groq_key, record_groq_key_usage
-
-            groq_key = await get_available_groq_key(estimated_tokens=512)
-            groq_model = os.getenv("GROQ_MODEL", "qwen/qwen3-32b")
-            gemini_key = os.getenv("GEMINI_API_KEY", "")
-
-            # Disable Qwen3 thinking to keep token budget for actual response.
-            _groq_messages = list(messages)
-            if "qwen" in groq_model.lower():
-                for i, msg in enumerate(_groq_messages):
-                    if msg.get("role") == "user":
-                        _groq_messages[i] = {**msg, "content": f"/no_think\n{msg['content']}"}
-                        break
-
-            async def _try_groq():
-                if not groq_key:
-                    return None, None
-                try:
-                    resp = await _throttled_post_json(
-                        provider="groq",
-                        url="https://api.groq.com/openai/v1/chat/completions",
-                        headers={"Authorization": f"Bearer {groq_key}", "Content-Type": "application/json"},
-                        payload={"model": groq_model, "messages": _groq_messages, "max_tokens": 512, "temperature": 0.7},
-                        httpx_module=httpx,
-                        timeout=20.0,
-                    )
-                    if resp is not None and resp.status_code == 200:
-                        data = resp.json()
-                        tokens = data.get("usage", {}).get("total_tokens", 500)
-                        await record_groq_key_usage(groq_key, tokens)
-                        return data["choices"][0]["message"]["content"], f"groq/{groq_model}"
-                except Exception as e:
-                    logger.warning(f"[generate_node] Groq failed: {e}")
-                return None, None
-
-            async def _try_gemini():
-                if not gemini_key:
-                    return None, None
-                try:
-                    gemini_contents = [{"role": "user", "parts": [{"text": user_input}]}]
-                    url = f"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key={gemini_key}"
-                    request_body = {
-                        "contents": gemini_contents,
-                        "systemInstruction": {"parts": [{"text": system_prompt}]},
-                    }
-                    resp = await _throttled_post_json(
-                        provider="gemini",
-                        url=url,
-                        payload=request_body,
-                        httpx_module=httpx,
-                        timeout=20.0,
-                    )
-                    if resp is not None and resp.status_code == 200:
-                        candidates = resp.json().get("candidates", [])
-                        if candidates:
-                            return candidates[0]["content"]["parts"][0]["text"], "gemini-2.0-flash"
-                except Exception as e:
-                    logger.warning(f"[generate_node] Gemini failed: {e}")
-                return None, None
-
-            # Launch both concurrently; pick first non-None result.
-            tasks = [_asyncio.ensure_future(_try_groq()), _asyncio.ensure_future(_try_gemini())]
-            done, pending = await _asyncio.wait(tasks, return_when=_asyncio.FIRST_COMPLETED)
-            for task in done:
-                try:
-                    _text, _model = task.result()
-                    if _text:
-                        response = _text
-                        model_used = _model
-                        break
-                except Exception as _exc:
-                    logger.debug("[nodes_v2] ignored: %s", _exc)
-                    pass
-            # If winner found, cancel the loser immediately.
-            if response:
-                for p in pending:
-                    p.cancel()
-            else:
-                # Wait for the second one too before falling back to Ollama.
-                if pending:
-                    done2, _ = await _asyncio.wait(pending, timeout=15.0)
-                    for task in done2:
-                        try:
-                            _text, _model = task.result()
-                            if _text:
-                                response = _text
-                                model_used = _model
-                                break
-                        except Exception as _exc:
-                            logger.debug("[nodes_v2] ignored: %s", _exc)
-                            pass
-
-            # Ollama — last resort, tight 15s timeout.
-            if not response:
-                from api.core.config import settings
-                ollama_url = settings.OLLAMA_BASE_URL
-                ollama_model = os.getenv("OLLAMA_MODEL", "lexilingo-qwen3-1.7b")
-                try:
-                    resp = await _throttled_post_json(
-                        provider="ollama",
-                        url=f"{ollama_url}/api/chat",
-                        payload={
-                            "model": ollama_model,
-                            "messages": messages,
-                            "stream": False,
-                            "options": {"num_predict": 256, "temperature": 0.7},
-                        },
-                        httpx_module=httpx,
-                        timeout=15.0,
-                        max_retries=1,
-                    )
-                    if resp is not None and resp.status_code == 200:
-                        response = resp.json().get("message", {}).get("content", "")
-                        model_used = f"ollama/{ollama_model}"
-                except Exception as e:
-                    logger.warning(f"[generate_node] Ollama failed: {e}")
-    
-    except Exception as e:
-        logger.error(f"[generate_node] LLM chain error: {e}")
-    
-    # 4. Deterministic extractive fallback
-    if not response:
-        response = _generate_extractive_fallback_response(errors, strategy, user_input, context)
-        model_used = "extractive_fallback"
-    
-    # Determine next action
-    if strategy == "socratic":
-        next_action = "ask"
-    elif error_count == 0:
-        next_action = "continue"
-    elif error_count <= 2:
-        next_action = "hint"
-    else:
-        next_action = "correct"
-    
-    # Calculate overall score
-    grammar_score = state.get("grammar_score", 0.8)
-    fluency_score = state.get("fluency_score", 0.8)
-    vocab_level = state.get("vocabulary_level", "B1")
-    overall_score = EvaluationAgent.compute_overall_score(grammar_score, fluency_score, vocab_level)
-
-    _update_ranker_from_generation(
-        question=user_input,
-        response=response,
-        retrieval_trace=list(state.get("retrieval_trace") or []),
-    )
-
-    # Generate personalized practice exercises via ContentAutoGenerator (cag_service)
-    action_plan = []
-    if errors or intent == "practice":
-        try:
-            from api.services.cag_service import ContentAutoGenerator
-            cag_gen = ContentAutoGenerator()
-            err_types = [err.get("type", "grammar") for err in errors if isinstance(err, dict)]
-            if not err_types:
-                err_types = ["grammar"]
-            
-            first_err_type = err_types[0] if errors else "vocabulary"
-            if "vocab" in first_err_type.lower() or intent == "practice":
-                vocab_ex = cag_gen.generate_vocabulary_exercise(
-                    level=level,
-                    error_patterns=err_types if errors else None,
-                    count=3
-                )
-                action_plan.append({
-                    "action": "practice",
-                    "type": "vocabulary",
-                    "concept": vocab_ex.get("topic", ""),
-                    "count": len(vocab_ex.get("words", [])),
-                    "exercise": vocab_ex
-                })
-            else:
-                grammar_drill = cag_gen.generate_grammar_drill(
-                    level=level,
-                    error_patterns=err_types,
-                    count=3
-                )
-                action_plan.append({
-                    "action": "practice",
-                    "type": "grammar",
-                    "concept": grammar_drill.get("grammar_point", ""),
-                    "count": len(grammar_drill.get("exercises", [])),
-                    "exercise": grammar_drill
-                })
-        except Exception as cag_err:
-            logger.warning(f"[generate_node] Failed to generate CAG practice: {cag_err}")
-
-    state["action_plan"] = action_plan
-
-    # Store response in Redis cache for future hits
-    if state.get("cache_policy", "on") == "on":
-        try:
-            # ── Tiered Cache Management (L0/L1 Promotion) ─────────────
-            # Nếu thông tin từ L2 được sử dụng, kiểm tra thăng hạng
-            doc_service = get_doc_intel_service()
-            trace = state.get("retrieval_trace", [])
-            is_l2_used = any(t.get("item_id", "").startswith("ext_") for t in trace[:3])
-            
-            if is_l2_used:
-                for t in trace[:3]:
-                    if t.get("item_id", "").startswith("ext_"):
-                        chunk_id = str(t.get("item_id") or "").replace("ext_", "")
-                        if doc_service.should_promote_to_cache(chunk_id):
-                            logger.info(f"[cache_promotion] Chunk {chunk_id[:8]} promoted to L1 cache")
-                            await _write_cache_entry(state, response, strategy, errors, overall_score, context)
-                            break
-            else:
-                # Mặc định cache cho các luồng KG/Rules để tối ưu tốc độ
-                await _write_cache_entry(state, response, strategy, errors, overall_score, context)
-        except Exception as e:
-            logger.debug(f"[generate_node] Cache write failed: {e}")
-    
-    latency_ms = int((time.time() - start_time) * 1000)
-    logger.info(f"[generate_node] Generated response via {model_used} in {latency_ms}ms")
-    
-    return {
-        "tutor_response": response,
-        "strategy": strategy,
-        "next_action": next_action,
-        "overall_score": overall_score,
-        "action_plan": action_plan,
-        "ttft_ms": latency_ms,
-        "models_used": [model_used],
-    }
-
-
-
-
 # ============================================================
 # NODE 6: NATIVE LANGUAGE HINT (AI-POWERED, Lazy Load)
 # ============================================================
@@ -1849,7 +725,7 @@ async def vietnamese_node(state: TraceCAGState) -> Dict[str, Any]:
 
         # --- Attempt 3: Hardcoded strings ---
         if not native_hint:
-            native_hint = _get_predefined_vietnamese(errors)
+            native_hint = _get_predefined_native_hint(errors, native_language)
             models_used.append("native_fallback")
 
         latency_ms = int((time.time() - start_time) * 1000)
@@ -1862,26 +738,69 @@ async def vietnamese_node(state: TraceCAGState) -> Dict[str, Any]:
     except Exception as e:
         logger.error(f"[vietnamese_node] Error: {e}")
         return {
-            "vietnamese_hint": _get_predefined_vietnamese(errors),
+            "vietnamese_hint": _get_predefined_native_hint(errors, native_language),
             "models_used": ["native_fallback"],
         }
 
 
-def _get_predefined_vietnamese(errors: list) -> str:
-    """Fallback predefined Vietnamese explanations"""
-    if not errors:
-        return "Câu của bạn rất tốt! Tiếp tục cố gắng nhé! "
-    
-    error_type = errors[0].get("type", "").lower()
-    explanations = {
+# Last-resort hardcoded explanations, keyed by language name (matches the
+# `native_language` values produced by api.utils.languages.iso_to_language_name).
+# Only the most common onboarding languages get a translated dict — anything
+# else falls back to a short English line rather than translating every string.
+_PREDEFINED_NATIVE_EXPLANATIONS: Dict[str, Dict[str, str]] = {
+    "Vietnamese": {
+        "_no_errors": "Câu của bạn rất tốt! Tiếp tục cố gắng nhé! ",
+        "_default": "Hãy chú ý quy tắc ngữ pháp này nhé!",
         "subject_verb_agreement": "Trong tiếng Anh, động từ phải hòa hợp với chủ ngữ. Với 'I/you/we/they' dùng động từ nguyên mẫu, với 'he/she/it' thêm -s hoặc -es.",
         "third_person_s": "Với chủ ngữ ngôi thứ 3 số ít (he, she, it), động từ cần thêm -s hoặc -es. Ví dụ: He goes, She works.",
         "past_tense": "Khi nói về quá khứ (yesterday, last week...), cần dùng thì quá khứ đơn. Động từ bất quy tắc cần học thuộc!",
         "present_perfect": "Thì hiện tại hoàn thành dùng: have/has + past participle. Ví dụ: have gone, has eaten.",
         "article": "Dùng 'a' trước phụ âm, 'an' trước nguyên âm (a, e, i, o, u). Ví dụ: a book, an apple.",
-    }
-    
-    return explanations.get(error_type, "Hãy chú ý quy tắc ngữ pháp này nhé!")
+    },
+    "Japanese": {
+        "_no_errors": "あなたの文章はとても良いです!頑張り続けてください!",
+        "_default": "この文法のルールに気をつけてください!",
+        "subject_verb_agreement": "英語では動詞は主語と一致させる必要があります。'I/you/we/they'には原形、'he/she/it'には-sか-esを付けます。",
+        "third_person_s": "三人称単数の主語(he, she, it)には、動詞に-sか-esを付けます。例:He goes, She works.",
+        "past_tense": "過去のことを話すとき(yesterday, last weekなど)は過去形を使います。不規則動詞は覚える必要があります!",
+        "present_perfect": "現在完了形は have/has + 過去分詞 を使います。例:have gone, has eaten.",
+        "article": "子音の前には'a'、母音(a, e, i, o, u)の前には'an'を使います。例:a book, an apple.",
+    },
+    "Korean": {
+        "_no_errors": "문장이 정말 좋아요! 계속 노력하세요!",
+        "_default": "이 문법 규칙에 주의하세요!",
+        "subject_verb_agreement": "영어에서는 동사가 주어와 일치해야 합니다. 'I/you/we/they'는 원형을, 'he/she/it'는 -s나 -es를 붙입니다.",
+        "third_person_s": "3인칭 단수 주어(he, she, it)는 동사에 -s나 -es를 붙입니다. 예: He goes, She works.",
+        "past_tense": "과거(yesterday, last week 등)를 말할 때는 과거 시제를 사용합니다. 불규칙 동사는 외워야 해요!",
+        "present_perfect": "현재완료는 have/has + 과거분사를 사용합니다. 예: have gone, has eaten.",
+        "article": "자음 앞에는 'a', 모음(a, e, i, o, u) 앞에는 'an'을 사용합니다. 예: a book, an apple.",
+    },
+    "Chinese": {
+        "_no_errors": "你的句子很好!继续努力!",
+        "_default": "请注意这个语法规则!",
+        "subject_verb_agreement": "在英语中,动词必须与主语一致。'I/you/we/they'用原形动词,'he/she/it'要加-s或-es。",
+        "third_person_s": "第三人称单数主语(he, she, it)的动词要加-s或-es。例如:He goes, She works.",
+        "past_tense": "说过去的事情(yesterday, last week等)要用过去时。不规则动词需要记住!",
+        "present_perfect": "现在完成时用:have/has + 过去分词。例如:have gone, has eaten.",
+        "article": "辅音前用'a',元音(a, e, i, o, u)前用'an'。例如:a book, an apple.",
+    },
+}
+
+_FALLBACK_NATIVE_NO_ERRORS = "Nice work, your sentence is correct! Keep practicing!"
+_FALLBACK_NATIVE_DEFAULT = "Pay attention to this grammar rule!"
+
+
+def _get_predefined_native_hint(errors: list, native_language: str) -> str:
+    """Last-resort fallback explanation in the learner's native language."""
+    explanations = _PREDEFINED_NATIVE_EXPLANATIONS.get(native_language)
+    if not explanations:
+        return _FALLBACK_NATIVE_NO_ERRORS if not errors else _FALLBACK_NATIVE_DEFAULT
+
+    if not errors:
+        return explanations["_no_errors"]
+
+    error_type = errors[0].get("type", "").lower()
+    return explanations.get(error_type, explanations["_default"])
 
 
 # ============================================================
diff --git a/ai-service/api/services/trace_cag/retrieve.py b/ai-service/api/services/trace_cag/retrieve.py
new file mode 100644
index 00000000..837917dc
--- /dev/null
+++ b/ai-service/api/services/trace_cag/retrieve.py
@@ -0,0 +1,502 @@
+"""
+TraceCAG retrieve_node — budgeted hybrid retrieval with fusion scoring (paper Alg. 5).
+
+Split out of nodes_v2.py (Phase 4 refactor) since this node alone carries the
+KG/vector/L2-external retrieval stages and fusion-score ranking logic.
+"""
+
+import asyncio
+import logging
+import math
+import re
+import time
+from typing import Any, Dict, List
+
+from api.services.trace_cag.state import TraceCAGState
+from api.services.document_intelligence import get_doc_intel_service
+from api.services.trace_cag.env_helpers import _env_float, _env_int, _clip01
+from api.services.trace_cag.retrieval_ranker import get_retrieval_ranker
+
+from api.services.trace_cag.kg_utils import (
+    _KG_QUERY_CACHE, _kg_cache_key, _kg_cache_get, _kg_cache_set,
+    _pack_kg_nodes_for_context,
+)
+
+from api.services.trace_cag.benchmark.adaptive import (
+    _adaptive_mode_enabled, _choose_adaptive_profile,
+)
+from api.services.trace_cag.benchmark.ranking import (
+    _select_diverse_multihop_evidence, _compute_evidence_budget,
+    _rank_benchmark_candidates, _ranker_enabled, _rank_with_online_ranker,
+    _build_benchmark_candidates,
+)
+
+logger = logging.getLogger(__name__)
+
+_FUSION_ALPHA = 0.5   # KG structural relevance weight
+_FUSION_BETA = 0.3    # Vector similarity weight
+_FUSION_GAMMA = 0.2   # Recency bonus weight
+_RECENCY_LAMBDA = 0.01  # Decay rate for recency bonus
+
+_retrieval_v3_instance = None
+
+
+async def _get_retrieval_v3():
+    """Lazy singleton for RetrievalServiceV3 (centrality + community ranking)."""
+    global _retrieval_v3_instance
+    if _retrieval_v3_instance is None:
+        from api.services.kg_service_v3 import get_kg_service
+        from api.services.retrieval_service_v3 import RetrievalServiceV3
+        _retrieval_v3_instance = RetrievalServiceV3(get_kg_service())
+    return _retrieval_v3_instance
+
+
+def _fusion_score(
+    kg_depth: int,
+    vec_sim: float,
+    last_used_turns_ago: int,
+) -> float:
+    """
+    Compute fusion score for a retrieved evidence item (paper Eq. 8).
+
+    s_kg  = 1 / (1 + depth)         — inverse hop distance
+    s_vec = cosine similarity        — from MiniLM
+    s_rec = exp(-λ · Δt)            — recency bonus
+    """
+    s_kg = 1.0 / (1.0 + kg_depth)
+    s_vec = vec_sim
+    s_rec = math.exp(-_RECENCY_LAMBDA * last_used_turns_ago)
+    return _FUSION_ALPHA * s_kg + _FUSION_BETA * s_vec + _FUSION_GAMMA * s_rec
+
+
+async def retrieve_node(state: TraceCAGState) -> Dict[str, Any]:
+    """
+    Budgeted hybrid retrieval with fusion scoring (paper Alg. 5).
+
+    Stage 1: Graph-local evidence (cheap) — KG concepts + diagnosis
+    Stage 2: Optional vector evidence (budgeted) — MiniLM similarity
+    Fusion:  score(e) = α·s_kg + β·s_vec + γ·s_rec  (Eq. 8)
+    """
+    logger.info("[retrieve_node] Budgeted hybrid retrieval...")
+    start_time = time.time()
+    retrieve_start = time.monotonic()
+
+    kg_budget_ms = max(0.0, _env_float("TRACECAG_RETRIEVE_BUDGET_KG_MS", 120.0))
+    vector_budget_ms = max(0.0, _env_float("TRACECAG_RETRIEVE_BUDGET_VECTOR_MS", 80.0))
+    fusion_budget_ms = max(0.0, _env_float("TRACECAG_RETRIEVE_BUDGET_FUSION_MS", 40.0))
+    total_budget_ms = kg_budget_ms + vector_budget_ms + fusion_budget_ms
+
+    def _elapsed_ms() -> float:
+        return (time.monotonic() - retrieve_start) * 1000.0
+
+    budget_exhausted = False
+
+    retrieval_policy = state.get("retrieval_policy", "full")
+    benchmark_context = (state.get("benchmark_context") or "").strip()
+    benchmark_task = state.get("benchmark_task") or ""
+    benchmark_metadata = state.get("benchmark_metadata") or {}
+    benchmark_ranker = str(benchmark_metadata.get("_benchmark_ranker") or "graph").strip().lower()
+    benchmark_mode = str(benchmark_metadata.get("_benchmark_mode") or "").strip().lower()
+    user_input = state.get("user_input", "")
+    adaptive_profile = str(state.get("adaptive_profile") or "").strip().lower()
+    adaptive_features = dict(state.get("adaptive_features") or {})
+    adaptive_controller = dict(state.get("adaptive_controller") or {})
+
+    if _adaptive_mode_enabled(state, benchmark_mode) and not adaptive_profile:
+        adaptive_choice = _choose_adaptive_profile(
+            state=state,
+            user_input=user_input,
+            benchmark_task=benchmark_task,
+            benchmark_mode=benchmark_mode,
+            benchmark_metadata=benchmark_metadata,
+        )
+        adaptive_profile = str(adaptive_choice.get("profile") or "balanced")
+        adaptive_features = dict(adaptive_choice.get("features") or {})
+        adaptive_controller = {
+            **dict(adaptive_choice.get("controller") or {}),
+            "explore": bool(adaptive_choice.get("explore", False)),
+            "objective_map": adaptive_choice.get("objective_map", {}),
+            "tau_reuse": adaptive_choice.get("tau_reuse"),
+            "tau_patch": adaptive_choice.get("tau_patch"),
+            "support_floor": adaptive_choice.get("support_floor"),
+            "evidence_budget_delta": adaptive_choice.get("evidence_budget_delta"),
+        }
+
+    kg_concepts = state.get("kg_seed_concepts", [])
+    kg_expanded = state.get("kg_expanded_nodes", [])
+    session_turn = len(state.get("conversation_history", []))
+    benchmark_candidates, relevant_ids = _build_benchmark_candidates(state)
+
+    # ── Stage 1: Graph-local evidence (cheap) ────────────────────────
+    # Each evidence item: {"text": ..., "kg_depth": ..., "vec_sim": ..., "turns_ago": ...}
+    evidence_items: List[Dict[str, Any]] = []
+
+    for concept_id in state.get("diagnosis_root_causes", []):
+        evidence_items.append({
+            "text": f"Grammar concept: {concept_id}",
+            "kg_depth": 0,
+            "vec_sim": 0.0,
+            "turns_ago": 0,
+        })
+
+    for node in kg_expanded:
+        depth = node.get("depth", 1) if isinstance(node, dict) else 1
+        evidence_items.append({
+            "text": f"Related: {node.get('id', '')} ({node.get('relation', '')})",
+            "kg_depth": depth,
+            "vec_sim": 0.0,
+            "turns_ago": session_turn,
+        })
+
+    # Query KG with top-K node retrieval and bounded context packing to control prompt size.
+    if not benchmark_candidates and not benchmark_context:
+        try:
+            from api.services.kg_service_v3 import get_kg_service
+
+            learner_level = state.get("learner_profile", {}).get("level", "B1")
+            top_k = max(1, _env_int("TRACECAG_KG_TOPK", 8))
+            token_budget = max(32, _env_int("TRACECAG_KG_CONTEXT_TOKEN_BUDGET", 160))
+
+            cache_key = _kg_cache_key(user_input, learner_level, top_k)
+            queried_nodes = _kg_cache_get(cache_key)
+            if queried_nodes is None:
+                kg = get_kg_service()
+                queried_nodes = kg.query_concepts(user_input, learner_level=learner_level, top_k=top_k)
+                _kg_cache_set(cache_key, queried_nodes)
+
+            packed_nodes = _pack_kg_nodes_for_context(queried_nodes, token_budget)
+            for node in packed_nodes:
+                title = str(node.get("title") or node.get("id") or "")
+                keywords = str(node.get("keywords") or "")
+                score = float(node.get("score") or 0.0)
+                evidence_items.append({
+                    "item_id": str(node.get("id") or title),
+                    "title": title,
+                    "text": f"Concept: {title}. Keywords: {keywords}",
+                    "kg_depth": 1,
+                    "vec_sim": max(0.0, min(1.0, score)),
+                    "turns_ago": session_turn,
+                })
+        except Exception as kg_exc:
+            logger.warning(f"[retrieve_node] KG top-K query skipped: {kg_exc}")
+
+    for error in state.get("diagnosis_errors", [])[:3]:
+        evidence_items.append({
+            "text": f"Error: '{error.get('span', '')}' → '{error.get('correction', '')}' — {error.get('explanation', '')}",
+            "kg_depth": 0,
+            "vec_sim": 0.0,
+            "turns_ago": 0,
+        })
+
+    if benchmark_candidates:
+        evidence_items = []
+        ranked_candidates = _rank_benchmark_candidates(
+            user_input,
+            benchmark_candidates,
+            benchmark_ranker,
+            benchmark_mode,
+            adaptive_profile,
+        )
+        for candidate in ranked_candidates:
+            final_score = float(candidate.get("fusion_score", candidate.get("vec_sim", 0.0)))
+            evidence_items.append({
+                "item_id": candidate["item_id"],
+                "title": candidate["title"],
+                "text": candidate["text"],
+                "kg_depth": candidate["kg_depth"],
+                "vec_sim": final_score,
+                "turns_ago": candidate["turns_ago"],
+                "graph_score": float(candidate.get("graph_score") or 0.0),
+                "memory_score": float(candidate.get("memory_score") or 0.0),
+                "precomputed_score": final_score,
+                "is_relevant": candidate["item_id"] in relevant_ids,
+            })
+    elif benchmark_context:
+        evidence_items.insert(0, {
+            "item_id": "benchmark_context",
+            "title": "benchmark_context",
+            "text": benchmark_context,
+            "kg_depth": 0,
+            "vec_sim": 1.0,
+            "turns_ago": 0,
+            "is_relevant": True,
+        })
+
+    # ── Stage 2: RetrievalServiceV3 (centrality + community ranking) ─────
+    vector_hits = []
+    if not benchmark_candidates and _elapsed_ms() <= (kg_budget_ms + vector_budget_ms):
+        errors = state.get("diagnosis_errors", [])
+        confidence = float(state.get("diagnosis_confidence", 0.0) or 0.0)
+        is_multihop_task = benchmark_task == "multihop_qa"
+
+        do_vector_search = True
+        max_hits = 5
+
+        if retrieval_policy == "rapid":
+            if len(errors) == 0 and confidence >= 0.85 and not is_multihop_task:
+                do_vector_search = False
+            elif len(errors) <= 2 and confidence >= 0.72:
+                max_hits = 3
+
+        if do_vector_search and _elapsed_ms() <= (kg_budget_ms + vector_budget_ms):
+            # ── Primary: RetrievalServiceV3 (centrality + community diversity) ──
+            try:
+                from api.models.v3_schemas import V3PipelineContext
+
+                retrieval_v3 = await _get_retrieval_v3()
+                ctx = V3PipelineContext(
+                    user_input=user_input,
+                    session_id=state.get("session_id", ""),
+                    user_id=state.get("user_id"),
+                )
+                seed_nodes = [
+                    c if isinstance(c, str) else c.get("id", "")
+                    for c in kg_concepts[:5]
+                ]
+                bundle = await retrieval_v3.retrieve(user_input, seed_nodes, ctx)
+
+                for hit in bundle.vector_hits[:max_hits]:
+                    snippet = getattr(hit, "snippet", hit.id)
+                    vector_hits.append({"text": snippet, "score": hit.score})
+                    evidence_items.append({
+                        "item_id": hit.id,
+                        "title": snippet,
+                        "text": f"Concept ({hit.id}): {snippet}",
+                        "kg_depth": 2,
+                        "vec_sim": hit.score,
+                        "turns_ago": session_turn,
+                    })
+
+                logger.info(
+                    f"[retrieve_node] RetrievalServiceV3: {len(vector_hits)} hits "
+                    f"(centrality+community ranked)"
+                )
+
+            except Exception as e:
+                logger.warning(
+                    f"[retrieve_node] RetrievalServiceV3 unavailable, "
+                    f"falling back to MiniLM gateway: {e}"
+                )
+                # ── Fallback: MiniLM gateway ──────────────────────────────────
+                try:
+                    from api.services.model_gateway import get_gateway
+
+                    gateway = await get_gateway()
+                    max_expanded = 10
+                    threshold = 0.3
+
+                    if retrieval_policy == "rapid" and len(errors) <= 2 and confidence >= 0.7:
+                        max_expanded = 5
+                        threshold = 0.35
+
+                    candidate_labels = []
+                    for c in kg_concepts:
+                        if isinstance(c, dict):
+                            candidate_labels.append(c.get("id", "") + " " + c.get("label", ""))
+                        else:
+                            candidate_labels.append(str(c))
+                    for node in kg_expanded[:max_expanded]:
+                        label = node.get("id", "") + " " + node.get("label", node.get("relation", ""))
+                        if label.strip() and label not in candidate_labels:
+                            candidate_labels.append(label)
+
+                    if candidate_labels:
+                        result = await gateway.invoke(
+                            "minilm", "invoke",
+                            {"task": "similarity", "query": user_input, "candidates": candidate_labels},
+                        )
+                        if result.get("success"):
+                            sim_results = result.get("data", {}).get("results", [])
+                            for r in sim_results:
+                                if r["score"] >= threshold:
+                                    vector_hits.append({"text": r["text"], "score": r["score"]})
+                                    evidence_items.append({
+                                        "text": f"Semantic match: {r['text']}",
+                                        "kg_depth": 2,
+                                        "vec_sim": r["score"],
+                                        "turns_ago": session_turn,
+                                    })
+
+                            vector_hits = vector_hits[:max_hits]
+                            logger.info(f"[retrieve_node] MiniLM fallback: {len(vector_hits)} hits")
+                except Exception as e2:
+                    logger.warning(f"[retrieve_node] Vector search fully skipped: {e2}")
+    elif not benchmark_candidates:
+        budget_exhausted = True
+
+    # ── Stage 3: L2 External Knowledge (Selective Retrieval) ─────────
+    # Phân tích xem có nên ép buộc tìm kiếm bên ngoài không (Proactive Dynamic Retrieval)
+    force_external = False
+    dynamic_patterns = [
+        r"\bhôm (qua|nay|kia)\b", r"\bmới (đây|nhất)\b", r"\bvừa mới\b",
+        r"\brecently\b", r"\byesterday\b", r"\btoday\b", r"\blatest\b", r"\bcurrent\b",
+        r"\bdo you know\b", r"\bnghe nói\b", r"\bbạn có biết\b", r"\bnews\b", r"\btin tức\b"
+    ]
+    if any(re.search(p, user_input, re.IGNORECASE) for p in dynamic_patterns):
+        force_external = True
+        logger.info("[retrieve_node] Dynamic intent detected. Forcing L2 Search.")
+
+    # Kích hoạt L2 nếu (thiếu dữ liệu) HOẶC (phát hiện intent cần tin tức thực tế)
+    if (len(evidence_items) < 3 or force_external) and not benchmark_candidates:
+        try:
+            doc_service = get_doc_intel_service()
+            # Nếu force_external, ta có thể điều chỉnh query để search hiệu quả hơn
+            search_query = user_input
+            if force_external and len(user_input) < 100:
+                # Bổ sung ngữ cảnh để search Tavily tốt hơn
+                search_query = f"latest information about {user_input}"
+
+            external_hits = await asyncio.wait_for(
+                doc_service.query_l2(search_query), timeout=5.0
+            )
+            for hit in external_hits:
+                # Tránh trùng lặp nếu đã có trong evidence_items
+                if any(e.get("chunk_id") == hit["id"] for e in evidence_items):
+                    continue
+
+                evidence_items.append({
+                    "item_id": f"ext_{hit['id']}",
+                    "title": "External Knowledge",
+                    "text": f"Context: {hit['content']}",
+                    "kg_depth": 3, # Tầng sâu hơn KG
+                    "vec_sim": hit["score"],
+                    "turns_ago": session_turn,
+                    "is_external": True,
+                    "chunk_id": hit["id"]
+                })
+            if external_hits:
+                logger.info(f"[retrieve_node] L2 Context injected: {len(external_hits)} chunks")
+        except Exception as e3:
+            logger.warning(f"[retrieve_node] L2 retrieval failed: {e3}")
+
+    # ── Fusion scoring and ranking ───────────────────────────────────
+    if _elapsed_ms() <= total_budget_ms:
+        for item in evidence_items:
+            if benchmark_candidates and "precomputed_score" in item:
+                item["fusion_score"] = float(item.get("precomputed_score") or 0.0)
+            else:
+                item["fusion_score"] = _fusion_score(
+                    kg_depth=item["kg_depth"],
+                    vec_sim=item["vec_sim"],
+                    last_used_turns_ago=item["turns_ago"],
+                )
+    else:
+        budget_exhausted = True
+        for item in evidence_items:
+            if "fusion_score" not in item:
+                item["fusion_score"] = float(item.get("vec_sim") or 0.0)
+
+    evidence_items = _rank_with_online_ranker(
+        question=user_input,
+        evidence_items=evidence_items,
+        allow_exploration=_adaptive_mode_enabled(state, benchmark_mode),
+        benchmark_mode=benchmark_mode,
+    )
+    evidence_budget = _compute_evidence_budget(
+        question=user_input,
+        retrieval_policy=retrieval_policy,
+        benchmark_mode=benchmark_mode,
+        benchmark_candidates=bool(benchmark_candidates),
+        adaptive_profile=adaptive_profile,
+        benchmark_task=benchmark_task,
+    )
+    if benchmark_candidates and benchmark_task in {"multihop_qa", "retrieval_qa"}:
+        top_evidence = _select_diverse_multihop_evidence(
+            items=evidence_items,
+            question=user_input,
+            budget=evidence_budget,
+        )
+    else:
+        top_evidence = evidence_items[:evidence_budget]
+    retrieval_trace = [
+        {
+            "item_id": str(item.get("item_id") or item.get("title") or f"item_{idx}"),
+            "title": str(item.get("title") or item.get("item_id") or ""),
+            "text": str(item.get("text") or ""),
+            "rank": idx + 1,
+            "score": float(item.get("fusion_score") or 0.0),
+            "is_relevant": bool(item.get("is_relevant") or False),
+        }
+        for idx, item in enumerate(top_evidence)
+    ]
+
+    if benchmark_candidates:
+        context_parts = []
+        for item in top_evidence:
+            title = str(item.get("title") or "").strip()
+            text = str(item.get("text") or "").strip()
+            context_parts.append(f"[{title}] {text}" if title else text)
+        retrieved_context = "\n".join(part for part in context_parts if part).strip()
+    elif benchmark_context and benchmark_task in {"multihop_qa", "retrieval_qa"}:
+        retrieved_context = benchmark_context
+    else:
+        context_parts = [item["text"] for item in top_evidence]
+        retrieved_context = "\n".join(context_parts) if context_parts else ""
+
+    jit_soft_graph = str(state.get("jit_soft_graph") or "").strip()
+    jit_graph_meta = dict(state.get("jit_graph_meta") or {})
+    if jit_soft_graph:
+        retrieved_context = (
+            f"[JIT_SOFT_GRAPH]\n{jit_soft_graph}\n\n"
+            f"{retrieved_context}".strip()
+        )
+
+    latency_ms = int((time.time() - start_time) * 1000)
+    logger.info(
+        f"[retrieve_node] {len(evidence_items)} candidates → top {len(top_evidence)} via fusion scoring"
+        f" (mode={benchmark_mode or 'default'}, ranker={benchmark_ranker}, latency={latency_ms}ms)"
+    )
+
+    ranker_snapshot = get_retrieval_ranker().snapshot() if _ranker_enabled() else {}
+    graph_update = dict(state.get("graph_update") or {})
+
+    return {
+        "vector_hits": vector_hits,
+        "retrieved_context": retrieved_context,
+        "jit_soft_graph": jit_soft_graph or None,
+        "jit_graph_meta": jit_graph_meta,
+        "retrieval_trace": retrieval_trace,
+        "adaptive_profile": adaptive_profile or None,
+        "adaptive_features": adaptive_features,
+        "adaptive_controller": adaptive_controller,
+        "retrieval_meta": {
+            "budget": {
+                "kg_ms": kg_budget_ms,
+                "vector_ms": vector_budget_ms,
+                "fusion_ms": fusion_budget_ms,
+                "total_ms": total_budget_ms,
+                "elapsed_ms": _elapsed_ms(),
+                "exhausted": budget_exhausted,
+            },
+            "fusion": {
+                "alpha": _FUSION_ALPHA,
+                "beta": _FUSION_BETA,
+                "gamma": _FUSION_GAMMA,
+                "recency_lambda": _RECENCY_LAMBDA,
+            },
+            "kg_topk": {
+                "top_k": max(1, _env_int("TRACECAG_KG_TOPK", 8)),
+                "context_token_budget": max(32, _env_int("TRACECAG_KG_CONTEXT_TOKEN_BUDGET", 160)),
+                "query_cache_size": len(_KG_QUERY_CACHE),
+            },
+            "jit_graph": jit_graph_meta,
+            "graph_update": {
+                "latency_ms": int(graph_update.get("latency_ms") or 0),
+                "nodes_added": int(graph_update.get("nodes_added") or 0),
+                "edges_added": int(graph_update.get("edges_added") or 0),
+            },
+            "mode": benchmark_mode or "default",
+            "ranker": benchmark_ranker,
+            "learned_ranker": {
+                "enabled": _ranker_enabled(),
+                "blend": _clip01(_env_float("TRACECAG_RANKER_BLEND", 0.42)),
+                "snapshot": ranker_snapshot,
+            },
+            "adaptive": {
+                "profile": adaptive_profile or None,
+                "features": adaptive_features,
+                "controller": adaptive_controller,
+            },
+        },
+        "models_used": ["retrieval_fusion"] + (["minilm"] if vector_hits else []),
+    }
diff --git a/ai-service/api/services/trace_cag/state.py b/ai-service/api/services/trace_cag/state.py
index ce9d0302..29f543d2 100644
--- a/ai-service/api/services/trace_cag/state.py
+++ b/ai-service/api/services/trace_cag/state.py
@@ -56,6 +56,7 @@ class CacheFingerprint(TypedDict, total=False):
     query_norm: str          # normalized user input
     intent: str              # diagnosed intent
     level: str               # CEFR level
+    native_language: str     # learner's native language (e.g. Vietnamese)
     root_concepts: List[str] # root-cause concept IDs
     session_turn: int        # turn number within session
 
@@ -75,7 +76,7 @@ class CacheEntry(TypedDict, total=False):
     fluency_score: float
     vocabulary_level: str
     action_plan: List[Dict[str, Any]]
-    created_at: float                  # t_c: timestamp (monotonic)
+    created_at: float                  # t_c: timestamp (wall-clock epoch — Redis-persisted, read across processes/hosts)
     ttl: int                           # seconds
 
 
diff --git a/ai-service/api/utils/languages.py b/ai-service/api/utils/languages.py
new file mode 100644
index 00000000..2b3cc944
--- /dev/null
+++ b/ai-service/api/utils/languages.py
@@ -0,0 +1,19 @@
+"""ISO 639-1 code -> English language name, scoped to the onboarding language
+list in flutter-app/lib/core/l10n/app_localizations.dart (AppLocales.metadata).
+"""
+
+from __future__ import annotations
+
+_ISO_TO_LANGUAGE_NAME: dict[str, str] = {
+    "vi": "Vietnamese",
+    "en": "English",
+    "ja": "Japanese",
+    "ko": "Korean",
+    "zh": "Chinese",
+    "fr": "French",
+    "es": "Spanish",
+}
+
+
+def iso_to_language_name(code: str) -> str:
+    return _ISO_TO_LANGUAGE_NAME.get((code or "").strip().lower(), "Vietnamese")
diff --git a/ai-service/constraints-ai.txt b/ai-service/constraints-ai.txt
index d344bd5f..3963254f 100644
--- a/ai-service/constraints-ai.txt
+++ b/ai-service/constraints-ai.txt
@@ -7,3 +7,4 @@ sentence-transformers==4.1.0
 faster-whisper==1.2.1
 moonshine-voice==0.0.65
 sherpa-onnx==1.13.3
+scipy==1.17.1
diff --git a/ai-service/docs/superpowers/plans/2026-07-04-tracecag-full-benchmark-run.md b/ai-service/docs/superpowers/plans/2026-07-04-tracecag-full-benchmark-run.md
new file mode 100644
index 00000000..989ef818
--- /dev/null
+++ b/ai-service/docs/superpowers/plans/2026-07-04-tracecag-full-benchmark-run.md
@@ -0,0 +1,123 @@
+# TRACE-CAG Full Benchmark Run Implementation Plan
+
+> **For agentic workers:** REQUIRED: Use superpowers:subagent-driven-development (if subagents available) or superpowers:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Run the TRACE-CAG benchmark end to end, identify real bottlenecks, fix confirmed issues minimally, and rerun the benchmark.
+
+**Architecture:** Use the existing `model-development/benchmark/benchmark.py` CLI and existing JSON report format. The workflow is offline sanity, mini live run, report analysis, minimal fixes if evidence demands them, focused verification, then full live run.
+
+**Tech Stack:** Python 3.12 venv, pytest, TRACE-CAG benchmark CLI, Groq `qwen/qwen3-32b`, JSON reports, shell logs.
+
+---
+
+## File Structure
+
+- Read: `docs/superpowers/specs/2026-07-04-tracecag-full-benchmark-run-design.md`
+- Read: `model-development/benchmark/benchmark.py`
+- Read: `model-development/benchmark/tracecag_bench/cli.py`
+- Read: `model-development/benchmark/tracecag_bench/reporting/json_report.py`
+- Output: `model-development/reports/benchmarks/*.json`
+- Output: `model-development/reports/benchmarks/logs/*.log`
+- Modify only if benchmark evidence proves a bug: benchmark runtime, reporting, cache reset, provider classification, or TRACE-CAG runtime files directly implicated by logs.
+
+## Chunk 1: Baseline Checks
+
+### Task 1: Confirm workspace and offline tests
+
+**Files:**
+- Read: git status
+- Test: `tests/benchmark/`
+- Test: `tests/trace_cag/test_cache_gate_benchmark_metadata.py`
+- Test: `tests/trace_cag/test_cache_gate_l1.py`
+- Test: `tests/trace_cag/test_l1_state_cache.py`
+- Test: `tests/trace_cag/test_l1_drift_probe_decisions.py`
+
+- [ ] Check `git status --short` and note unrelated dirty files.
+- [ ] Run:
+
+```bash
+venv/bin/python -m pytest tests/benchmark \
+  tests/trace_cag/test_cache_gate_benchmark_metadata.py \
+  tests/trace_cag/test_cache_gate_l1.py \
+  tests/trace_cag/test_l1_state_cache.py \
+  tests/trace_cag/test_l1_drift_probe_decisions.py -q
+```
+
+- [ ] Expected: tests pass before any live benchmark starts.
+
+## Chunk 2: Mini Live Run
+
+### Task 2: Run all benchmark protocols with small n
+
+**Files:**
+- Output: `model-development/reports/benchmarks/logs/tracecag-mini-live-<timestamp>.log`
+- Output: benchmark JSON reports in `model-development/reports/benchmarks/`
+
+- [ ] Create a timestamped log path.
+- [ ] Run:
+
+```bash
+venv/bin/python model-development/benchmark/benchmark.py all \
+  --n 5 \
+  --cache-repeats 2 \
+  --generation-policy auto \
+  --evidence-mode candidate_pool \
+  --provider groq \
+  --model qwen/qwen3-32b
+```
+
+- [ ] Capture stdout and stderr to the log.
+- [ ] If the command exits non-zero, inspect reports and log before changing code.
+
+## Chunk 3: Report Analysis
+
+### Task 3: Summarize bottlenecks from JSON reports
+
+**Files:**
+- Read: newly generated `model-development/reports/benchmarks/*.json`
+- Read: mini live log
+
+- [ ] For each report, record `run_validation.passed`.
+- [ ] For public QA, record F1, R@5, MRR@5, cache hit, warm hit, L1 hit, mean/P50/P95 latency, providers, fallback rate, errors.
+- [ ] For drift safety, record route accuracy, unsafe acceptance, patch recall, fallback rate, routing overhead, latency, errors.
+- [ ] Treat provider fallback, `bypass`, errors, failed validation, suspicious cache leakage, and high routing overhead as possible bottlenecks.
+- [ ] Do not tune ranking quality from `n=5` alone.
+
+## Chunk 4: Minimal Fixes
+
+### Task 4: Fix only confirmed defects
+
+**Files:**
+- Modify only the file named by the log/report root cause.
+- Add or update the smallest focused test beside existing tests.
+
+- [ ] Grep every caller of the function before editing it.
+- [ ] Write or update one focused failing test.
+- [ ] Implement the smallest root-cause fix.
+- [ ] Run the focused test.
+- [ ] Run the baseline focused test suite from Chunk 1.
+- [ ] Commit only files touched for the fix.
+
+## Chunk 5: Rerun and Full Benchmark
+
+### Task 5: Rerun affected slice, then run full benchmark
+
+**Files:**
+- Output: `model-development/reports/benchmarks/logs/tracecag-full-live-<timestamp>.log`
+- Output: benchmark JSON reports in `model-development/reports/benchmarks/`
+
+- [ ] If a fix was made, rerun the failed mini slice.
+- [ ] Run:
+
+```bash
+venv/bin/python model-development/benchmark/benchmark.py all \
+  --n 20 \
+  --cache-repeats 2 \
+  --generation-policy auto \
+  --evidence-mode candidate_pool \
+  --provider groq \
+  --model qwen/qwen3-32b
+```
+
+- [ ] Capture stdout and stderr to the full live log.
+- [ ] Summarize final reports, bottlenecks, fixes, and unresolved risks.
diff --git a/ai-service/docs/superpowers/specs/2026-07-04-tracecag-full-benchmark-run-design.md b/ai-service/docs/superpowers/specs/2026-07-04-tracecag-full-benchmark-run-design.md
new file mode 100644
index 00000000..263ef232
--- /dev/null
+++ b/ai-service/docs/superpowers/specs/2026-07-04-tracecag-full-benchmark-run-design.md
@@ -0,0 +1,144 @@
+# TRACE-CAG Full Benchmark Run Design
+
+## Objective
+
+Run a production-backed TRACE-CAG benchmark, monitor the results, identify real
+bottlenecks, make only necessary fixes, then rerun the affected benchmark scope
+and the full benchmark.
+
+The run uses the existing benchmark CLI:
+
+```text
+model-development/benchmark/benchmark.py
+```
+
+This spec does not redesign the benchmark package. It defines the execution and
+analysis workflow for this run.
+
+## Current Context
+
+The benchmark package already supports:
+
+- `public-qa` for HotpotQA, 2WikiMultihopQA, MuSiQue, and `query_clusters`
+- `drift-safety` for TRACE-DriftBench
+- `all` to run all public QA datasets followed by drift safety
+- strict provider validation through `run_validation`
+- JSON reports under `model-development/reports/benchmarks/`
+
+The repo currently has unrelated dirty Flutter files outside `ai-service`.
+This run must not touch or commit those changes.
+
+## Approved Approach
+
+Use a two-stage live run:
+
+1. Mini live preflight across all datasets.
+2. Full live run after mini reports are clean or after minimal fixes.
+
+This avoids wasting provider quota on a full run if provider validation,
+fallback behavior, cache reset, or report wiring is already broken.
+
+## Execution Plan
+
+### Stage 1: Offline Sanity
+
+Run the focused benchmark and TRACE-CAG cache tests:
+
+```text
+venv/bin/python -m pytest tests/benchmark \
+  tests/trace_cag/test_cache_gate_benchmark_metadata.py \
+  tests/trace_cag/test_cache_gate_l1.py \
+  tests/trace_cag/test_l1_state_cache.py \
+  tests/trace_cag/test_l1_drift_probe_decisions.py -q
+```
+
+The live benchmark should not start if this fails.
+
+### Stage 2: Mini Live Benchmark
+
+Run:
+
+```text
+venv/bin/python model-development/benchmark/benchmark.py all \
+  --n 5 \
+  --cache-repeats 2 \
+  --generation-policy auto \
+  --evidence-mode candidate_pool \
+  --provider groq \
+  --model qwen/qwen3-32b
+```
+
+Capture stdout/stderr to a timestamped log in:
+
+```text
+model-development/reports/benchmarks/logs/
+```
+
+### Stage 3: Bottleneck Analysis
+
+Inspect every generated JSON report for:
+
+- `run_validation.passed`
+- provider fallback or `bypass` output
+- mode-level `errors`
+- latency mean, P50, P95, and routing overhead
+- cold and warm cache hit rates
+- L0 and L1 rates
+- public QA F1, R@5, and MRR@5
+- drift route accuracy, unsafe acceptance, patch recall, and fallback rate
+- KG preflight status
+
+Treat a bottleneck as actionable only if the report or log gives direct
+evidence. Do not tune thresholds or ranking weights from one noisy mini sample.
+
+### Stage 4: Minimal Fixes
+
+Allowed fixes:
+
+- provider/model classification bugs
+- report validation or report parsing defects
+- cache reset leakage
+- benchmark CLI wiring defects
+- clear runtime errors found in logs
+- missing observability needed to diagnose the run
+
+Avoid broad refactors, new abstractions, or ranking algorithm changes unless the
+benchmark proves a root-cause bug.
+
+Every non-trivial fix needs the smallest focused test that would fail without
+the fix.
+
+### Stage 5: Rerun
+
+After any fix:
+
+1. Run focused tests.
+2. Rerun the failed mini benchmark slice.
+3. Run the full benchmark:
+
+```text
+venv/bin/python model-development/benchmark/benchmark.py all \
+  --n 20 \
+  --cache-repeats 2 \
+  --generation-policy auto \
+  --evidence-mode candidate_pool \
+  --provider groq \
+  --model qwen/qwen3-32b
+```
+
+## Success Criteria
+
+The task is complete when:
+
+- focused tests pass
+- mini live reports are analyzed
+- any confirmed benchmark/runtime issue is fixed with a focused test
+- full live benchmark completes or clearly fails due to external quota/network
+- final reports are summarized with bottlenecks, fixes, and remaining risks
+
+## Non-Goals
+
+- No new benchmark framework
+- No broad TRACE-CAG refactor
+- No provider fallback masking to make reports pass
+- No edits to unrelated Flutter files
diff --git a/ai-service/pytest.ini b/ai-service/pytest.ini
new file mode 100644
index 00000000..4ecb1ad2
--- /dev/null
+++ b/ai-service/pytest.ini
@@ -0,0 +1,5 @@
+[pytest]
+testpaths = tests
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*
diff --git a/ai-service/requirements.txt b/ai-service/requirements.txt
index 8daaab58..0ccd2678 100644
--- a/ai-service/requirements.txt
+++ b/ai-service/requirements.txt
@@ -68,7 +68,8 @@ langchain-community>=0.4.2
 llama-cpp-python>=0.3.33
 
 # Audio Processing (for HuBERT resampling)
-scipy>=1.18.0
+# scipy 1.18+ requires Python 3.12; CI runs Python 3.11.
+scipy>=1.17.1,<1.18.0
 
 # HTTP Downloads
 requests>=2.34.2
diff --git a/ai-service/service/__init__.py b/ai-service/service/__init__.py
new file mode 100644
index 00000000..51db22d2
--- /dev/null
+++ b/ai-service/service/__init__.py
@@ -0,0 +1 @@
+"""Portable service packages for LexiLingo components."""
diff --git a/ai-service/service/tracecag_service/README.md b/ai-service/service/tracecag_service/README.md
new file mode 100644
index 00000000..4264c02f
--- /dev/null
+++ b/ai-service/service/tracecag_service/README.md
@@ -0,0 +1,207 @@
+# TRACE-CAG Service Package
+
+`service/tracecag_service` is the portable packaging layer for TRACE-CAG. It
+lets another Python project call the TRACE-CAG contract without importing the
+FastAPI app at module import time.
+
+The existing LexiLingo app remains unchanged. The production adapter imports
+`api.services.trace_cag.graph.get_trace_cag()` lazily only when the first
+analysis request runs.
+
+## What This Package Contains
+
+| File | Purpose |
+| --- | --- |
+| `schemas.py` | Stable `TraceCAGRequest` and `TraceCAGResponse` DTOs. |
+| `runtime.py` | `TraceCAGService`: validation, timeout, batch concurrency, response normalization. |
+| `ports.py` | `TraceCAGAnalyzer` protocol for pluggable implementations. |
+| `config.py` | Portable config and env loading via `TRACECAG_SERVICE_*`. |
+| `core/fingerprint.py` | Lightweight state fingerprinting for cache keys and L1 buckets. |
+| `core/scar_l1.py` | Pure SCAR-L1 reuse/patch/full decision logic. |
+| `adapters/lexilingo.py` | Lazy bridge to the current LexiLingo TRACE-CAG pipeline. |
+| `adapters/memory.py` | Dependency-free adapter for tests, demos, and new projects. |
+
+## Quick Start Inside LexiLingo
+
+```python
+from service.tracecag_service import TraceCAGRequest
+from service.tracecag_service.adapters.lexilingo import create_lexilingo_service
+
+service = create_lexilingo_service()
+
+response = await service.analyze(
+    TraceCAGRequest(
+        user_input="I go to school yesterday.",
+        session_id="session-1",
+        user_id="user-1",
+        learner_profile={"level": "B1"},
+    )
+)
+
+print(response.tutor_response)
+print(response.metadata["cache_decision"])
+```
+
+Use this when you want the portable contract but still want the existing
+LexiLingo KG, Redis, model gateway, and LangGraph runtime.
+
+## Quick Start In Another Project
+
+Copy or vendor the `service/tracecag_service` package, then implement the
+`TraceCAGAnalyzer` port:
+
+```python
+from service.tracecag_service import TraceCAGRequest, TraceCAGResponse, TraceCAGService
+
+
+class MyAnalyzer:
+    async def analyze(self, request: TraceCAGRequest) -> TraceCAGResponse:
+        # Connect your KG, cache, retriever, LLM, or workflow here.
+        return TraceCAGResponse(
+            tutor_response=f"Handled: {request.user_input}",
+            metadata={"path": "slow", "cache_hit": False},
+        )
+
+
+service = TraceCAGService(MyAnalyzer())
+response = await service.analyze_text("Explain past simple", session_id="demo")
+```
+
+The service wrapper does not care whether the implementation is LangGraph,
+FastAPI, a CLI tool, a notebook, or a background worker. The only required
+method is:
+
+```python
+async def analyze(request: TraceCAGRequest) -> TraceCAGResponse | dict:
+    ...
+```
+
+## Dependency-Free Demo Adapter
+
+The memory adapter proves the package works without Redis, Kuzu, FastAPI, or
+LLM keys. It implements lightweight L0 exact reuse and L1 SCAR-style near-hit
+reuse.
+
+```python
+from service.tracecag_service import TraceCAGService
+from service.tracecag_service.adapters.memory import InMemoryTraceCAGAnalyzer
+
+service = TraceCAGService(InMemoryTraceCAGAnalyzer())
+
+first = await service.analyze_text("Who founded AlphaSoft?", session_id="s1")
+second = await service.analyze_text("Who founded AlphaSoft?", session_id="s1")
+near = await service.analyze_text("Who created AlphaSoft?", session_id="s1")
+
+assert first.metadata["cache_decision"] == "full"
+assert second.metadata["cache_layer"] == "L0"
+assert near.metadata["cache_layer"] == "L1"
+```
+
+Use it for package-level tests or as a placeholder while wiring a real project
+adapter.
+
+## Request Fields
+
+`TraceCAGRequest` is intentionally close to the current pipeline signature:
+
+| Field | Meaning |
+| --- | --- |
+| `user_input` | Required user text or final transcript. |
+| `session_id` | Conversation/session boundary for history and cache state. |
+| `user_id` | Optional user identity for personalization. |
+| `input_type` | `"text"` or `"voice"`. |
+| `learner_profile` | Level, errors, progress, vocabulary count, or project-specific profile fields. |
+| `conversation_history` | Already-loaded turns. Supplying it lets callers skip a store lookup. |
+| `stt_final` | Optional final-only STT event payload. |
+| `cache_policy` | `"on"` or `"off"`. |
+| `retrieval_policy` | Existing pipeline retrieval knob, usually `"full"` or `"rapid"`. |
+| `diagnosis_policy` | Existing pipeline diagnosis knob, usually `"auto"` or `"rules"`. |
+| `generation_policy` | Existing generation knob, including `"auto"` or `"skip"` for streaming prep. |
+| `benchmark_*` | Optional benchmark task/context/metadata hooks. |
+| `kg_seed_concepts` | Preloaded graph concepts from another cache or caller. |
+| `return_raw_state` | Ask adapters to attach raw pipeline state when supported. |
+
+## Response Fields
+
+`TraceCAGResponse` normalizes either a dataclass response or a raw dict:
+
+| Field | Meaning |
+| --- | --- |
+| `tutor_response` | Final user-facing text. |
+| `corrections` | Grammar or language feedback objects. |
+| `linked_concepts` | KG or lightweight concept IDs used by the response. |
+| `action_plan` | Suggested follow-up actions. |
+| `scores` | Fluency, grammar, overall, vocabulary, or project-specific metrics. |
+| `action` | Strategy and next action. |
+| `metadata` | Latency, cache path, cache decision, service adapter, and request metadata. |
+| `raw_state` | Optional raw implementation state. |
+| `error` | Non-throwing error string for validation, timeout, or runtime failure. |
+
+## Runtime Configuration
+
+```python
+from service.tracecag_service import TraceCAGServiceConfig
+
+config = TraceCAGServiceConfig(
+    timeout_seconds=20,
+    max_concurrency=2,
+    include_raw_state_by_default=False,
+)
+```
+
+Environment variables use the `TRACECAG_SERVICE_` prefix:
+
+| Env var | Default |
+| --- | --- |
+| `TRACECAG_SERVICE_NAME` | `tracecag-service` |
+| `TRACECAG_SERVICE_VERSION` | `0.1.0` |
+| `TRACECAG_SERVICE_TIMEOUT_SECONDS` | `30.0` |
+| `TRACECAG_SERVICE_MAX_CONCURRENCY` | `4` |
+| `TRACECAG_SERVICE_DEFAULT_SESSION_ID` | `tracecag-session` |
+| `TRACECAG_SERVICE_INCLUDE_RAW_STATE` | `false` |
+| `TRACECAG_SERVICE_STRICT_VALIDATION` | `true` |
+
+## Batch Calls
+
+```python
+requests = [
+    TraceCAGRequest(user_input="Explain articles", session_id="s1"),
+    TraceCAGRequest(user_input="Practice past tense", session_id="s2"),
+]
+
+responses = await service.analyze_many(requests)
+```
+
+`TraceCAGService` bounds parallelism with `max_concurrency`.
+
+## Error Handling
+
+The wrapper returns errors as `TraceCAGResponse` instead of raising for common
+service boundary failures:
+
+- validation: empty input, missing session, unsupported input type, invalid cache policy
+- timeout: analyzer exceeded `timeout_seconds`
+- runtime: analyzer raised an exception
+
+Check:
+
+```python
+if response.error:
+    print(response.metadata["error_type"], response.error)
+```
+
+## Theory And Mechanism
+
+For the full explanation of the cache theory, PCC/SCAR-L1 decision flow, and
+how to implement this package in another project, read:
+
+`docs/tracecag_service_guide.md`
+
+## Tests
+
+```bash
+pytest tests/service -q
+```
+
+These tests do not start FastAPI, Redis, KG, or any model provider.
+
diff --git a/ai-service/service/tracecag_service/__init__.py b/ai-service/service/tracecag_service/__init__.py
new file mode 100644
index 00000000..269d48ec
--- /dev/null
+++ b/ai-service/service/tracecag_service/__init__.py
@@ -0,0 +1,17 @@
+"""Portable TRACE-CAG service package.
+
+The package is intentionally additive. Importing it does not import the
+existing FastAPI app or `api.services.trace_cag`; use the LexiLingo adapter
+when you want to bind this contract to the current application pipeline.
+"""
+
+from service.tracecag_service.config import TraceCAGServiceConfig
+from service.tracecag_service.runtime import TraceCAGService
+from service.tracecag_service.schemas import TraceCAGRequest, TraceCAGResponse
+
+__all__ = [
+    "TraceCAGRequest",
+    "TraceCAGResponse",
+    "TraceCAGService",
+    "TraceCAGServiceConfig",
+]
diff --git a/ai-service/service/tracecag_service/adapters/__init__.py b/ai-service/service/tracecag_service/adapters/__init__.py
new file mode 100644
index 00000000..2abb9cde
--- /dev/null
+++ b/ai-service/service/tracecag_service/adapters/__init__.py
@@ -0,0 +1,13 @@
+"""Adapters that bind the portable service to concrete runtimes."""
+
+from service.tracecag_service.adapters.lexilingo import (
+    LexiLingoTraceCAGAnalyzer,
+    create_lexilingo_service,
+)
+from service.tracecag_service.adapters.memory import InMemoryTraceCAGAnalyzer
+
+__all__ = [
+    "InMemoryTraceCAGAnalyzer",
+    "LexiLingoTraceCAGAnalyzer",
+    "create_lexilingo_service",
+]
diff --git a/ai-service/service/tracecag_service/adapters/lexilingo.py b/ai-service/service/tracecag_service/adapters/lexilingo.py
new file mode 100644
index 00000000..354d3608
--- /dev/null
+++ b/ai-service/service/tracecag_service/adapters/lexilingo.py
@@ -0,0 +1,60 @@
+"""Lazy adapter from the portable service contract to this app's pipeline."""
+
+from __future__ import annotations
+
+import inspect
+from typing import Any, Awaitable, Callable
+
+from service.tracecag_service.config import TraceCAGServiceConfig
+from service.tracecag_service.runtime import TraceCAGService
+from service.tracecag_service.schemas import TraceCAGRequest, TraceCAGResponse
+
+
+PipelineFactory = Callable[[], Any | Awaitable[Any]]
+
+
+class LexiLingoTraceCAGAnalyzer:
+    """Adapter for the existing `api.services.trace_cag` implementation.
+
+    The import is intentionally lazy so the portable package can be imported in
+    another project without importing FastAPI, Redis, KG, or model code.
+    """
+
+    def __init__(self, pipeline_factory: PipelineFactory | None = None) -> None:
+        self._pipeline_factory = pipeline_factory
+        self._pipeline: Any | None = None
+
+    async def analyze(self, request: TraceCAGRequest) -> TraceCAGResponse:
+        pipeline = await self._get_pipeline()
+        result = await pipeline.analyze(**request.to_pipeline_kwargs())
+        return TraceCAGResponse.from_mapping(
+            result,
+            raw_state=result if request.return_raw_state and isinstance(result, dict) else None,
+        )
+
+    async def _get_pipeline(self) -> Any:
+        if self._pipeline is not None:
+            return self._pipeline
+
+        if self._pipeline_factory is not None:
+            candidate = self._pipeline_factory()
+            self._pipeline = await candidate if inspect.isawaitable(candidate) else candidate
+            return self._pipeline
+
+        from api.services.trace_cag.graph import get_trace_cag
+
+        self._pipeline = await get_trace_cag()
+        return self._pipeline
+
+
+def create_lexilingo_service(
+    *,
+    config: TraceCAGServiceConfig | None = None,
+    pipeline_factory: PipelineFactory | None = None,
+) -> TraceCAGService:
+    """Create a portable service bound to the current LexiLingo pipeline."""
+
+    return TraceCAGService(
+        analyzer=LexiLingoTraceCAGAnalyzer(pipeline_factory=pipeline_factory),
+        config=config,
+    )
diff --git a/ai-service/service/tracecag_service/adapters/memory.py b/ai-service/service/tracecag_service/adapters/memory.py
new file mode 100644
index 00000000..b3877164
--- /dev/null
+++ b/ai-service/service/tracecag_service/adapters/memory.py
@@ -0,0 +1,187 @@
+"""Dependency-free TRACE-CAG adapter for demos, tests, and new projects."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+import time
+
+from service.tracecag_service.core.fingerprint import (
+    TraceCAGFingerprint,
+    build_cache_key,
+    build_fingerprint,
+    build_graph_bucket,
+)
+from service.tracecag_service.core.scar_l1 import (
+    L1Candidate,
+    L1Decision,
+    L1Request,
+    decide_l1_reuse,
+)
+from service.tracecag_service.schemas import TraceCAGRequest, TraceCAGResponse
+
+
+@dataclass(slots=True)
+class _MemoryEntry:
+    cache_key: str
+    bucket: str
+    fingerprint: TraceCAGFingerprint
+    response: TraceCAGResponse
+    created_at: float
+    ttl: int
+
+
+class InMemoryTraceCAGAnalyzer:
+    """Tiny portable analyzer that exercises TRACE-CAG cache semantics.
+
+    It does not call an LLM. Use it to prove the service package can run
+    without LexiLingo infrastructure, or as a starting point for another
+    project to replace with its own KG/LLM implementation.
+    """
+
+    def __init__(self, *, ttl_seconds: int = 3600) -> None:
+        self.ttl_seconds = ttl_seconds
+        self._entries: dict[str, _MemoryEntry] = {}
+        self._buckets: dict[str, list[str]] = {}
+
+    async def analyze(self, request: TraceCAGRequest) -> TraceCAGResponse:
+        fingerprint = build_fingerprint(
+            user_input=request.user_input,
+            learner_profile=request.learner_profile,
+            conversation_history=request.conversation_history,
+        )
+        cache_key = build_cache_key(fingerprint)
+        bucket = build_graph_bucket(fingerprint)
+        now = time.monotonic()
+
+        if request.cache_policy != "off":
+            exact = self._entries.get(cache_key)
+            if exact and not self._is_stale(exact, now):
+                return self._from_cache(exact, "reuse", "L0", 0.0)
+
+            candidate = self._best_l1_candidate(fingerprint, now)
+            if candidate is not None:
+                entry, decision = candidate
+                return self._from_cache(entry, decision.decision, "L1", decision.risk)
+
+        response = self._generate_response(request, fingerprint)
+        if request.cache_policy != "off":
+            self._entries[cache_key] = _MemoryEntry(
+                cache_key=cache_key,
+                bucket=bucket,
+                fingerprint=fingerprint,
+                response=response.copy(),
+                created_at=now,
+                ttl=self.ttl_seconds,
+            )
+            self._buckets.setdefault(bucket, []).append(cache_key)
+        return response
+
+    async def close(self) -> None:
+        self._entries.clear()
+        self._buckets.clear()
+
+    def _best_l1_candidate(
+        self,
+        fingerprint: TraceCAGFingerprint,
+        now: float,
+    ) -> tuple[_MemoryEntry, L1Decision] | None:
+        request_sig = L1Request(
+            query_norm=fingerprint.query_norm,
+            intent=fingerprint.intent,
+            level=fingerprint.level,
+            profile_epoch=fingerprint.profile_epoch,
+            session_turn=fingerprint.session_turn,
+            concepts=set(fingerprint.concepts),
+            entities=set(fingerprint.entities),
+            answer_target=fingerprint.answer_target,
+            relation_hints=set(fingerprint.relation_hints),
+        )
+
+        best: tuple[float, _MemoryEntry, L1Decision] | None = None
+        for entry in self._entries.values():
+            if self._is_stale(entry, now):
+                continue
+            candidate_sig = L1Candidate(
+                cache_key=entry.cache_key,
+                query_norm=entry.fingerprint.query_norm,
+                intent=entry.fingerprint.intent,
+                level=entry.fingerprint.level,
+                profile_epoch=entry.fingerprint.profile_epoch,
+                session_turn=entry.fingerprint.session_turn,
+                concepts=set(entry.fingerprint.concepts),
+                entities=set(entry.fingerprint.entities),
+                answer_target=entry.fingerprint.answer_target,
+                relation_hints=set(entry.fingerprint.relation_hints),
+                created_at=entry.created_at,
+                ttl=entry.ttl,
+            )
+            decision = decide_l1_reuse(request_sig, candidate_sig, now=now)
+            if not decision.safe_to_reuse:
+                continue
+            score = decision.rank_score
+            if best is None or score > best[0]:
+                best = (score, entry, decision)
+        if best is None:
+            return None
+        return best[1], best[2]
+
+    def _from_cache(
+        self,
+        entry: _MemoryEntry,
+        decision: str,
+        layer: str,
+        risk: float,
+    ) -> TraceCAGResponse:
+        response = entry.response.copy()
+        if decision == "patch":
+            response.tutor_response = (
+                f"{response.tutor_response}\n\n"
+                "State-compatible cache patch applied for this request."
+            )
+        response.metadata = {
+            **response.metadata,
+            "path": "fast",
+            "cache_hit": True,
+            "cache_decision": decision,
+            "cache_layer": layer,
+            "cache_bucket": entry.bucket,
+            "reuse_risk": risk,
+            "tokens_saved": max(response.metadata.get("tokens_saved", 0), 128),
+        }
+        return response
+
+    def _generate_response(
+        self,
+        request: TraceCAGRequest,
+        fingerprint: TraceCAGFingerprint,
+    ) -> TraceCAGResponse:
+        return TraceCAGResponse(
+            tutor_response=(
+                "TRACE-CAG portable service analyzed the request. "
+                f"Intent: {fingerprint.intent}. Level: {fingerprint.level}."
+            ),
+            linked_concepts=sorted(fingerprint.concepts),
+            scores={
+                "fluency": 0.0,
+                "grammar": 0.0,
+                "overall": 0.0,
+                "vocabulary_level": fingerprint.level,
+            },
+            action={
+                "strategy": "portable",
+                "next": "wire_real_kg_llm_adapter",
+            },
+            metadata={
+                "path": "slow",
+                "cache_hit": False,
+                "cache_decision": "full",
+                "cache_layer": "none",
+                "cache_bucket": build_graph_bucket(fingerprint),
+                "reuse_risk": 1.0,
+                "tokens_saved": 0,
+                "input_type": request.input_type,
+            },
+        )
+
+    def _is_stale(self, entry: _MemoryEntry, now: float) -> bool:
+        return (now - entry.created_at) >= entry.ttl
diff --git a/ai-service/service/tracecag_service/config.py b/ai-service/service/tracecag_service/config.py
new file mode 100644
index 00000000..329a570c
--- /dev/null
+++ b/ai-service/service/tracecag_service/config.py
@@ -0,0 +1,69 @@
+"""Configuration for the portable TRACE-CAG service wrapper."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+import os
+
+
+def _env_bool(name: str, default: bool) -> bool:
+    raw = os.getenv(name)
+    if raw is None:
+        return default
+    return raw.strip().lower() in {"1", "true", "yes", "on"}
+
+
+def _env_float(name: str, default: float) -> float:
+    raw = os.getenv(name)
+    if raw is None:
+        return default
+    try:
+        return float(raw)
+    except ValueError:
+        return default
+
+
+def _env_int(name: str, default: int) -> int:
+    raw = os.getenv(name)
+    if raw is None:
+        return default
+    try:
+        return int(raw)
+    except ValueError:
+        return default
+
+
+@dataclass(frozen=True)
+class TraceCAGServiceConfig:
+    """Runtime knobs that are safe to carry across projects."""
+
+    service_name: str = "tracecag-service"
+    version: str = "0.1.0"
+    timeout_seconds: float = 30.0
+    max_concurrency: int = 4
+    default_session_id: str = "tracecag-session"
+    include_raw_state_by_default: bool = False
+    strict_validation: bool = True
+
+    @classmethod
+    def from_env(cls, prefix: str = "TRACECAG_SERVICE_") -> "TraceCAGServiceConfig":
+        """Build config from environment variables without requiring settings.py."""
+
+        return cls(
+            service_name=os.getenv(f"{prefix}NAME", cls.service_name),
+            version=os.getenv(f"{prefix}VERSION", cls.version),
+            timeout_seconds=_env_float(f"{prefix}TIMEOUT_SECONDS", cls.timeout_seconds),
+            max_concurrency=max(1, _env_int(f"{prefix}MAX_CONCURRENCY", cls.max_concurrency)),
+            default_session_id=os.getenv(
+                f"{prefix}DEFAULT_SESSION_ID",
+                cls.default_session_id,
+            ),
+            include_raw_state_by_default=_env_bool(
+                f"{prefix}INCLUDE_RAW_STATE",
+                cls.include_raw_state_by_default,
+            ),
+            strict_validation=_env_bool(
+                f"{prefix}STRICT_VALIDATION",
+                cls.strict_validation,
+            ),
+        )
diff --git a/ai-service/service/tracecag_service/core/__init__.py b/ai-service/service/tracecag_service/core/__init__.py
new file mode 100644
index 00000000..a2a09b56
--- /dev/null
+++ b/ai-service/service/tracecag_service/core/__init__.py
@@ -0,0 +1,25 @@
+"""Portable TRACE-CAG core algorithms."""
+
+from service.tracecag_service.core.fingerprint import (
+    TraceCAGFingerprint,
+    build_cache_key,
+    build_fingerprint,
+    build_graph_bucket,
+)
+from service.tracecag_service.core.scar_l1 import (
+    L1Candidate,
+    L1Decision,
+    L1Request,
+    decide_l1_reuse,
+)
+
+__all__ = [
+    "TraceCAGFingerprint",
+    "build_cache_key",
+    "build_fingerprint",
+    "build_graph_bucket",
+    "L1Candidate",
+    "L1Decision",
+    "L1Request",
+    "decide_l1_reuse",
+]
diff --git a/ai-service/service/tracecag_service/core/fingerprint.py b/ai-service/service/tracecag_service/core/fingerprint.py
new file mode 100644
index 00000000..e49f8d9e
--- /dev/null
+++ b/ai-service/service/tracecag_service/core/fingerprint.py
@@ -0,0 +1,215 @@
+"""Portable state fingerprinting used by TRACE-CAG service adapters."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+import hashlib
+import re
+from typing import Any, Mapping, Sequence
+
+
+_CEFR_ORDER = ("A1", "A2", "B1", "B2", "C1", "C2")
+
+_ENTITY_STOPWORDS = {
+    "what", "which", "who", "whom", "whose", "where", "when", "why", "how",
+    "many", "much", "the", "and", "that", "this", "those", "these", "with",
+    "from", "into", "onto", "about", "person", "company", "film", "movie",
+    "creator", "created", "founder", "founded", "director", "directed",
+    "writer", "author", "mother", "father", "wife", "brother", "born",
+    "birth", "year", "date", "country", "city", "language", "award",
+}
+
+
+@dataclass(frozen=True, slots=True)
+class TraceCAGFingerprint:
+    """Portable request-state signature for cache and reuse decisions."""
+
+    query_norm: str
+    intent: str
+    level: str
+    profile_epoch: int
+    session_turn: int
+    concepts: set[str] = field(default_factory=set)
+    entities: set[str] = field(default_factory=set)
+    answer_target: str = "feedback"
+    relation_hints: set[str] = field(default_factory=set)
+
+
+def normalize_query(text: str) -> str:
+    """Normalize user text for stable cache keys."""
+
+    return " ".join((text or "").strip().lower().split())
+
+
+def infer_intent(text: str) -> str:
+    """Cheap pre-diagnosis intent classifier."""
+
+    query = normalize_query(text)
+    if any(token in query for token in ("why", "explain", "what does", "how does")):
+        return "explain"
+    if any(token in query for token in ("practice", "exercise", "quiz", "train")):
+        return "practice"
+    if query.endswith("?") or any(
+        token in query
+        for token in ("who", "where", "when", "which", "what", "how many")
+    ):
+        return "ask"
+    return "correct"
+
+
+def extract_lightweight_concepts(text: str) -> set[str]:
+    """Approximate root concepts before a full KG or LLM diagnosis."""
+
+    query = normalize_query(text)
+    concepts: set[str] = set()
+    pattern_map = {
+        r"\b(i|you|we|they)\s+(is|was)\b": "concept:grammar.subject_verb_agreement",
+        r"\b(he|she|it)\s+(go|want|need|have|do)\b": "concept:grammar.third_person_s",
+        r"\byesterday\b.*\b(go|come|eat|buy|need|want)\b": "concept:grammar.past_time_markers",
+        r"\b(have|has)\s+went\b": "concept:grammar.present_perfect",
+        r"\bmore\s+better\b|\bmore\s+worse\b": "concept:grammar.comparatives",
+        r"\bexplain\b|\bwhy\b|\bwhat does\b": "intent:explain",
+        r"\bpractice\b|\bexercise\b|\bquiz\b": "intent:practice",
+    }
+    for pattern, concept in pattern_map.items():
+        if re.search(pattern, query, re.IGNORECASE):
+            concepts.add(concept)
+
+    for token in re.findall(r"[a-z0-9][a-z0-9'-]{3,}", query)[:8]:
+        concepts.add(f"token:{token.strip('-')}")
+    return {concept for concept in concepts if concept}
+
+
+def extract_entities(text: str) -> set[str]:
+    """Extract stable entity-ish tokens for state compatibility checks."""
+
+    query = normalize_query(text)
+    entities = {
+        token.strip("-'")
+        for token in re.findall(r"[a-z0-9][a-z0-9'-]{2,}", query)
+        if token not in _ENTITY_STOPWORDS and len(token.strip("-'")) >= 3
+    }
+    return {entity for entity in entities if entity}
+
+
+def answer_target_hint(text: str) -> str:
+    """Classify the coarse answer target as a hard reuse signal."""
+
+    query = normalize_query(text)
+    if any(token in query for token in ("when", "what year", "which year", "date")):
+        return "time"
+    if any(token in query for token in ("where", "country", "city", "place", "located")):
+        return "place"
+    if any(token in query for token in ("how many", "how much", "times", "number")):
+        return "number"
+    if any(
+        token in query
+        for token in ("who", "mother", "father", "wife", "brother", "founder", "director")
+    ):
+        return "person"
+    if any(token in query for token in ("which", "what")):
+        return "entity"
+    return "feedback"
+
+
+def relation_hints(text: str) -> set[str]:
+    """Map lexical cues into coarse relation classes for SCAR-L1."""
+
+    query = normalize_query(text)
+    relation_map = {
+        "founder": ("founder", "founded", "co-founded", "created", "creator"),
+        "maker": ("makes", "made by", "manufacturer", "behind"),
+        "birth": ("born", "birth"),
+        "director": ("director", "directed"),
+        "author": ("writer", "author", "wrote"),
+        "family": ("mother", "father", "wife", "brother"),
+        "time_order": ("came out first", "came first", "first", "earlier", "before", "released"),
+        "comparison": ("taller", "higher", "larger", "older", "younger"),
+        "location": ("where", "country", "city", "located", "place"),
+        "award": ("award", "won"),
+    }
+    hints: set[str] = set()
+    for relation, cues in relation_map.items():
+        if any(cue in query for cue in cues):
+            hints.add(relation)
+    return hints
+
+
+def profile_epoch(profile: Mapping[str, Any] | None) -> int:
+    """Compress learner profile state into a stable epoch integer."""
+
+    profile = profile or {}
+    level = normalize_level(str(profile.get("level") or "B1"))
+    sessions_completed = int(profile.get("sessions_completed") or 0)
+    vocabulary_count = int(profile.get("vocabulary_count") or 0)
+    common_errors = profile.get("common_errors") or []
+    error_bucket = len(common_errors) // 2 if isinstance(common_errors, Sequence) else 0
+    material = f"{level}|{sessions_completed // 3}|{vocabulary_count // 200}|{error_bucket}"
+    return int(hashlib.md5(material.encode()).hexdigest()[:8], 16)
+
+
+def normalize_level(level: str) -> str:
+    """Return a known CEFR level, defaulting to B1 for unknown input."""
+
+    upper = (level or "B1").upper()
+    return upper if upper in _CEFR_ORDER else "B1"
+
+
+def build_fingerprint(
+    *,
+    user_input: str,
+    learner_profile: Mapping[str, Any] | None = None,
+    conversation_history: Sequence[Mapping[str, Any]] | None = None,
+) -> TraceCAGFingerprint:
+    """Build the portable request fingerprint."""
+
+    profile = learner_profile or {}
+    history = conversation_history or []
+    entities = extract_entities(user_input)
+    concepts = set(extract_lightweight_concepts(user_input))
+    concepts.update(f"entity:{entity}" for entity in entities)
+    return TraceCAGFingerprint(
+        query_norm=normalize_query(user_input),
+        intent=infer_intent(user_input),
+        level=normalize_level(str(profile.get("level") or "B1")),
+        profile_epoch=profile_epoch(profile),
+        session_turn=len(history),
+        concepts=concepts,
+        entities=entities,
+        answer_target=answer_target_hint(user_input),
+        relation_hints=relation_hints(user_input),
+    )
+
+
+def build_cache_key(fingerprint: TraceCAGFingerprint) -> str:
+    """Build an exact L0 cache key."""
+
+    material = "|".join(
+        [
+            fingerprint.query_norm,
+            fingerprint.intent,
+            fingerprint.level,
+            str(fingerprint.profile_epoch),
+            str(fingerprint.session_turn),
+        ]
+    )
+    return hashlib.md5(material.encode()).hexdigest()
+
+
+def build_graph_bucket(fingerprint: TraceCAGFingerprint) -> str:
+    """Build a graph-state bucket for L1 candidate pooling."""
+
+    material = "|".join(
+        [
+            "tracecag_l1",
+            fingerprint.level,
+            fingerprint.intent,
+            str(fingerprint.profile_epoch),
+            str(fingerprint.session_turn // 2),
+            fingerprint.answer_target,
+            *sorted(fingerprint.relation_hints),
+            *sorted(fingerprint.entities)[:8],
+            *sorted(fingerprint.concepts)[:8],
+        ]
+    )
+    return hashlib.md5(material.encode()).hexdigest()
diff --git a/ai-service/service/tracecag_service/core/scar_l1.py b/ai-service/service/tracecag_service/core/scar_l1.py
new file mode 100644
index 00000000..c32a19f2
--- /dev/null
+++ b/ai-service/service/tracecag_service/core/scar_l1.py
@@ -0,0 +1,133 @@
+"""SCAR-L1 state-certified reuse decisions.
+
+This module is pure Python so it can be copied into another project without
+Redis, FastAPI, LangGraph, or model-provider dependencies.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+import time
+
+
+@dataclass(frozen=True, slots=True)
+class L1Request:
+    """State signature for the current request."""
+
+    query_norm: str
+    intent: str
+    level: str
+    profile_epoch: int
+    session_turn: int
+    concepts: set[str] = field(default_factory=set)
+    entities: set[str] = field(default_factory=set)
+    answer_target: str = ""
+    relation_hints: set[str] = field(default_factory=set)
+    evidence_hash: str = ""
+
+
+@dataclass(frozen=True, slots=True)
+class L1Candidate:
+    """State signature for an L1 cache candidate."""
+
+    cache_key: str
+    query_norm: str
+    intent: str
+    level: str
+    profile_epoch: int
+    session_turn: int
+    concepts: set[str] = field(default_factory=set)
+    entities: set[str] = field(default_factory=set)
+    answer_target: str = ""
+    relation_hints: set[str] = field(default_factory=set)
+    evidence_hash: str = ""
+    created_at: float = 0.0
+    ttl: int = 3600
+
+
+@dataclass(frozen=True, slots=True)
+class L1Decision:
+    """SCAR-L1 ternary decision."""
+
+    decision: str
+    risk: float
+    rank_score: float
+    reasons: tuple[str, ...]
+    safe_to_reuse: bool
+
+
+def _jaccard(left: set[str], right: set[str]) -> float:
+    if not left and not right:
+        return 1.0
+    return len(left & right) / max(len(left | right), 1)
+
+
+def _empty_or_equal(left: str, right: str) -> bool:
+    return not left or not right or left == right
+
+
+def _compatible_relations(left: set[str], right: set[str]) -> bool:
+    if not left or not right:
+        return True
+    return left == right
+
+
+def decide_l1_reuse(
+    request: L1Request,
+    candidate: L1Candidate,
+    *,
+    now: float | None = None,
+    tau_reuse: float = 0.25,
+    tau_patch: float = 0.55,
+    concept_floor: float = 0.50,
+) -> L1Decision:
+    """Decide whether an L1 candidate can be reused, patched, or rejected."""
+
+    current_time = time.monotonic() if now is None else now
+    reasons: list[str] = []
+
+    if request.level != candidate.level:
+        reasons.append("level_mismatch")
+    if request.profile_epoch != candidate.profile_epoch:
+        reasons.append("profile_epoch_mismatch")
+    if not _empty_or_equal(request.intent, candidate.intent):
+        reasons.append("intent_mismatch")
+    if not _empty_or_equal(request.answer_target, candidate.answer_target):
+        reasons.append("answer_target_mismatch")
+    if not _empty_or_equal(request.evidence_hash, candidate.evidence_hash):
+        reasons.append("evidence_mismatch")
+    if not _compatible_relations(request.relation_hints, candidate.relation_hints):
+        reasons.append("relation_mismatch")
+
+    concept_overlap = _jaccard(request.concepts, candidate.concepts)
+    if concept_overlap < concept_floor:
+        reasons.append("concept_overlap_below_floor")
+
+    age_ratio = min(
+        max((current_time - candidate.created_at) / max(candidate.ttl, 1), 0.0),
+        1.0,
+    )
+    if age_ratio >= 1.0:
+        reasons.append("stale_candidate")
+
+    entity_overlap = _jaccard(request.entities, candidate.entities)
+    relation_overlap = _jaccard(request.relation_hints, candidate.relation_hints)
+    intent_drift = 0.0 if _empty_or_equal(request.intent, candidate.intent) else 1.0
+
+    risk = (
+        0.30 * intent_drift
+        + 0.25 * (1.0 - concept_overlap)
+        + 0.20 * (1.0 - entity_overlap)
+        + 0.15 * (1.0 - relation_overlap)
+        + 0.10 * age_ratio
+    )
+    risk = round(max(0.0, min(1.0, risk)), 6)
+    rank_score = (1.0 - risk) + (0.30 * concept_overlap) + (0.20 * entity_overlap)
+
+    if reasons:
+        return L1Decision("full", risk, rank_score, tuple(reasons), False)
+    if request.query_norm == candidate.query_norm and risk <= tau_reuse:
+        return L1Decision("reuse", risk, rank_score, ("exact_or_normalized_match",), True)
+    if risk <= tau_patch:
+        return L1Decision("patch", risk, rank_score, ("state_compatible_near_hit",), True)
+    return L1Decision("full", risk, rank_score, ("risk_above_patch_threshold",), False)
diff --git a/ai-service/service/tracecag_service/ports.py b/ai-service/service/tracecag_service/ports.py
new file mode 100644
index 00000000..a18c7db7
--- /dev/null
+++ b/ai-service/service/tracecag_service/ports.py
@@ -0,0 +1,25 @@
+"""Ports that decouple the service package from any one application."""
+
+from __future__ import annotations
+
+from typing import Any, Mapping, Protocol, runtime_checkable
+
+from service.tracecag_service.schemas import TraceCAGRequest, TraceCAGResponse
+
+
+@runtime_checkable
+class TraceCAGAnalyzer(Protocol):
+    """Analyzer contract implemented by real pipelines or test adapters."""
+
+    async def analyze(
+        self,
+        request: TraceCAGRequest,
+    ) -> TraceCAGResponse | Mapping[str, Any]:
+        """Analyze a request and return either a normalized response or mapping."""
+
+
+class SupportsClose(Protocol):
+    """Optional async close hook used by adapters with external resources."""
+
+    async def close(self) -> None:
+        """Release adapter resources."""
diff --git a/ai-service/service/tracecag_service/runtime.py b/ai-service/service/tracecag_service/runtime.py
new file mode 100644
index 00000000..d95c3745
--- /dev/null
+++ b/ai-service/service/tracecag_service/runtime.py
@@ -0,0 +1,137 @@
+"""Public runtime wrapper for portable TRACE-CAG analyzers."""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import Iterable
+from typing import Any
+
+from service.tracecag_service.config import TraceCAGServiceConfig
+from service.tracecag_service.ports import TraceCAGAnalyzer
+from service.tracecag_service.schemas import TraceCAGRequest, TraceCAGResponse
+
+
+class TraceCAGService:
+    """Small stable facade around a pluggable TRACE-CAG analyzer."""
+
+    def __init__(
+        self,
+        analyzer: TraceCAGAnalyzer,
+        config: TraceCAGServiceConfig | None = None,
+    ) -> None:
+        self.analyzer = analyzer
+        self.config = config or TraceCAGServiceConfig()
+
+    async def analyze(
+        self,
+        request: TraceCAGRequest,
+    ) -> TraceCAGResponse:
+        """Run one analysis call with validation, timeout, and normalization."""
+
+        validation_error = self._validate(request)
+        if validation_error:
+            return self._error_response(request, validation_error, error_type="validation")
+
+        try:
+            result = await asyncio.wait_for(
+                self.analyzer.analyze(request),
+                timeout=self.config.timeout_seconds,
+            )
+            response = TraceCAGResponse.from_mapping(result)
+            self._stamp_metadata(response, request)
+            if self.config.include_raw_state_by_default and response.raw_state is None:
+                response.raw_state = response.extra.pop("raw_state", None)
+            return response
+        except asyncio.TimeoutError:
+            return self._error_response(request, "TRACE-CAG service timed out", error_type="timeout")
+        except Exception as exc:
+            return self._error_response(request, str(exc), error_type="runtime")
+
+    async def analyze_text(
+        self,
+        text: str,
+        *,
+        session_id: str | None = None,
+        **kwargs: Any,
+    ) -> TraceCAGResponse:
+        """Convenience entry point for simple text-only integrations."""
+
+        request = TraceCAGRequest.from_text(
+            text,
+            session_id=session_id or self.config.default_session_id,
+            **kwargs,
+        )
+        return await self.analyze(request)
+
+    async def analyze_many(
+        self,
+        requests: Iterable[TraceCAGRequest],
+    ) -> list[TraceCAGResponse]:
+        """Analyze multiple requests with bounded concurrency."""
+
+        semaphore = asyncio.Semaphore(max(1, self.config.max_concurrency))
+
+        async def _run(item: TraceCAGRequest) -> TraceCAGResponse:
+            async with semaphore:
+                return await self.analyze(item)
+
+        return await asyncio.gather(*[_run(request) for request in requests])
+
+    async def close(self) -> None:
+        """Close the adapter when it provides an async close hook."""
+
+        close = getattr(self.analyzer, "close", None)
+        if close is not None:
+            await close()
+
+    def _validate(self, request: TraceCAGRequest) -> str | None:
+        if not self.config.strict_validation:
+            return None
+        if not request.user_input or not request.user_input.strip():
+            return "user_input is required"
+        if not request.session_id or not request.session_id.strip():
+            return "session_id is required"
+        if request.input_type not in {"text", "voice"}:
+            return "input_type must be 'text' or 'voice'"
+        if request.cache_policy not in {"on", "off"}:
+            return "cache_policy must be 'on' or 'off'"
+        return None
+
+    def _stamp_metadata(
+        self,
+        response: TraceCAGResponse,
+        request: TraceCAGRequest,
+    ) -> None:
+        response.metadata = {
+            **response.metadata,
+            "service": {
+                "name": self.config.service_name,
+                "version": self.config.version,
+                "adapter": type(self.analyzer).__name__,
+            },
+            "request": {
+                "session_id": request.session_id,
+                "input_type": request.input_type,
+            },
+        }
+
+    def _error_response(
+        self,
+        request: TraceCAGRequest,
+        message: str,
+        *,
+        error_type: str,
+    ) -> TraceCAGResponse:
+        response = TraceCAGResponse(
+            tutor_response="",
+            error=message,
+            metadata={
+                "path": "error",
+                "cache_hit": False,
+                "cache_decision": "full",
+                "cache_layer": "none",
+                "error_type": error_type,
+            },
+        )
+        self._stamp_metadata(response, request)
+        return response
diff --git a/ai-service/service/tracecag_service/schemas.py b/ai-service/service/tracecag_service/schemas.py
new file mode 100644
index 00000000..1958094f
--- /dev/null
+++ b/ai-service/service/tracecag_service/schemas.py
@@ -0,0 +1,166 @@
+"""Stable request and response contracts for TRACE-CAG."""
+
+from __future__ import annotations
+
+from copy import deepcopy
+from dataclasses import dataclass, field
+from typing import Any, Mapping
+
+
+@dataclass(slots=True)
+class TraceCAGRequest:
+    """Portable input contract for any TRACE-CAG implementation."""
+
+    user_input: str
+    session_id: str = "tracecag-session"
+    user_id: str | None = None
+    input_type: str = "text"
+    learner_profile: dict[str, Any] | None = None
+    conversation_history: list[dict[str, Any]] | None = None
+    stt_final: dict[str, Any] | None = None
+    cache_policy: str = "on"
+    retrieval_policy: str = "full"
+    diagnosis_policy: str = "auto"
+    generation_policy: str = "auto"
+    benchmark_task: str | None = None
+    benchmark_context: str | None = None
+    benchmark_metadata: dict[str, Any] | None = None
+    kg_seed_concepts: list[str] | None = None
+    return_raw_state: bool = False
+    metadata: dict[str, Any] = field(default_factory=dict)
+
+    @classmethod
+    def from_text(
+        cls,
+        text: str,
+        *,
+        session_id: str = "tracecag-session",
+        **kwargs: Any,
+    ) -> "TraceCAGRequest":
+        """Convenience constructor for simple text calls."""
+
+        return cls(user_input=text, session_id=session_id, **kwargs)
+
+    def to_pipeline_kwargs(self) -> dict[str, Any]:
+        """Map the portable request to the current LexiLingo pipeline signature."""
+
+        kwargs: dict[str, Any] = {
+            "user_input": self.user_input,
+            "session_id": self.session_id,
+            "user_id": self.user_id,
+            "input_type": self.input_type,
+            "learner_profile": deepcopy(self.learner_profile),
+            "conversation_history": deepcopy(self.conversation_history),
+            "stt_final": deepcopy(self.stt_final),
+            "cache_policy": self.cache_policy,
+            "retrieval_policy": self.retrieval_policy,
+            "diagnosis_policy": self.diagnosis_policy,
+            "generation_policy": self.generation_policy,
+            "benchmark_task": self.benchmark_task,
+            "benchmark_context": self.benchmark_context,
+            "benchmark_metadata": deepcopy(self.benchmark_metadata),
+            "kg_seed_concepts": deepcopy(self.kg_seed_concepts),
+            "return_raw_state": self.return_raw_state,
+        }
+        return {key: value for key, value in kwargs.items() if value is not None}
+
+
+@dataclass(slots=True)
+class TraceCAGResponse:
+    """Portable output contract normalized from any TRACE-CAG implementation."""
+
+    tutor_response: str = ""
+    corrections: list[dict[str, Any]] = field(default_factory=list)
+    linked_concepts: list[Any] = field(default_factory=list)
+    action_plan: list[dict[str, Any]] = field(default_factory=list)
+    vietnamese_hint: str | None = None
+    pronunciation_tip: str | None = None
+    scores: dict[str, Any] = field(default_factory=dict)
+    action: dict[str, Any] = field(default_factory=dict)
+    metadata: dict[str, Any] = field(default_factory=dict)
+    audio: dict[str, Any] | None = None
+    raw_state: dict[str, Any] | None = None
+    error: str | None = None
+    extra: dict[str, Any] = field(default_factory=dict)
+
+    @classmethod
+    def from_mapping(
+        cls,
+        payload: Mapping[str, Any] | "TraceCAGResponse",
+        *,
+        raw_state: Mapping[str, Any] | None = None,
+    ) -> "TraceCAGResponse":
+        """Normalize a dict response or raw pipeline state into this contract."""
+
+        if isinstance(payload, TraceCAGResponse):
+            response = payload.copy()
+            if raw_state is not None:
+                response.raw_state = deepcopy(dict(raw_state))
+            return response
+
+        data = dict(payload)
+        known = {
+            "tutor_response",
+            "corrections",
+            "linked_concepts",
+            "action_plan",
+            "vietnamese_hint",
+            "pronunciation_tip",
+            "scores",
+            "action",
+            "metadata",
+            "audio",
+            "raw_state",
+            "error",
+        }
+        metadata = deepcopy(data.get("metadata") or {})
+        if not metadata:
+            metadata = {
+                "latency_ms": data.get("latency_ms", 0),
+                "path": data.get("path", "slow"),
+                "cache_hit": data.get("cache_hit", False),
+                "cache_decision": data.get("cache_decision", "full"),
+                "cache_layer": data.get("cache_layer", "none"),
+            }
+
+        return cls(
+            tutor_response=str(data.get("tutor_response") or ""),
+            corrections=deepcopy(data.get("corrections") or []),
+            linked_concepts=deepcopy(data.get("linked_concepts") or data.get("kg_seed_concepts") or []),
+            action_plan=deepcopy(data.get("action_plan") or []),
+            vietnamese_hint=data.get("vietnamese_hint"),
+            pronunciation_tip=data.get("pronunciation_tip"),
+            scores=deepcopy(data.get("scores") or {}),
+            action=deepcopy(data.get("action") or {}),
+            metadata=metadata,
+            audio=deepcopy(data.get("audio")),
+            raw_state=deepcopy(dict(raw_state or data.get("raw_state") or {})) or None,
+            error=data.get("error"),
+            extra={key: deepcopy(value) for key, value in data.items() if key not in known},
+        )
+
+    def copy(self) -> "TraceCAGResponse":
+        """Return a detached copy that callers can mutate safely."""
+
+        return TraceCAGResponse.from_mapping(self.to_dict(include_raw_state=True))
+
+    def to_dict(self, *, include_raw_state: bool = False) -> dict[str, Any]:
+        """Serialize to a plain dict suitable for API responses."""
+
+        payload: dict[str, Any] = {
+            "tutor_response": self.tutor_response,
+            "corrections": deepcopy(self.corrections),
+            "linked_concepts": deepcopy(self.linked_concepts),
+            "action_plan": deepcopy(self.action_plan),
+            "vietnamese_hint": self.vietnamese_hint,
+            "pronunciation_tip": self.pronunciation_tip,
+            "scores": deepcopy(self.scores),
+            "action": deepcopy(self.action),
+            "metadata": deepcopy(self.metadata),
+            "audio": deepcopy(self.audio),
+            "error": self.error,
+            **deepcopy(self.extra),
+        }
+        if include_raw_state and self.raw_state is not None:
+            payload["raw_state"] = deepcopy(self.raw_state)
+        return payload
diff --git a/ai-service/tests/benchmark/test_datasets.py b/ai-service/tests/benchmark/test_datasets.py
index 4f5bffda..d8d2c2a2 100644
--- a/ai-service/tests/benchmark/test_datasets.py
+++ b/ai-service/tests/benchmark/test_datasets.py
@@ -1,3 +1,4 @@
+import json
 from pathlib import Path
 
 from tracecag_bench.datasets.driftbench import load_driftbench
@@ -15,6 +16,57 @@ def test_public_loader_preserves_context_docs_and_deduplicates_titles():
     assert sample.answers
 
 
+def test_public_loader_splits_bracketed_context_into_candidate_docs(tmp_path):
+    path = tmp_path / "cluster.jsonl"
+    row = {
+        "id": "cluster-1",
+        "text": "Which doc answers the bridge question?",
+        "output": {"answer": "Final answer"},
+        "metadata": {
+            "context": "[Bridge Page] Bridge text.\n[Answer Page] Final answer text.",
+            "supporting_titles": ["Bridge Page", "Answer Page"],
+        },
+    }
+    path.write_text(json.dumps(row), encoding="utf-8")
+
+    sample = load_public_qa(path, dataset="query_clusters", n=None, seed=0)[0]
+
+    assert [doc.title for doc in sample.context_docs] == ["Bridge Page", "Answer Page"]
+    assert [doc.text for doc in sample.context_docs] == ["Bridge text.", "Final answer text."]
+
+
+def test_public_loader_keeps_single_context_fallback_for_unstructured_text(tmp_path):
+    path = tmp_path / "fallback.jsonl"
+    row = {
+        "id": "fallback-1",
+        "text": "Question?",
+        "output": {"answer": "Answer"},
+        "metadata": {"context": "Plain unstructured context."},
+    }
+    path.write_text(json.dumps(row), encoding="utf-8")
+
+    sample = load_public_qa(path, dataset="custom", n=None, seed=0)[0]
+
+    assert len(sample.context_docs) == 1
+    assert sample.context_docs[0].title == "benchmark_context"
+    assert sample.context_docs[0].text == "Plain unstructured context."
+
+
+def test_query_clusters_supporting_titles_are_candidate_docs():
+    path = ROOT / "model-development/datasets/benchmarks/query_clusters/validation.jsonl"
+    samples = load_public_qa(path, dataset="query_clusters", n=None, seed=0)
+
+    missing = []
+    for sample in samples:
+        titles = {doc.title.strip().lower() for doc in sample.context_docs}
+        missing.extend(
+            title for title in sample.supporting_titles
+            if title.strip().lower() not in titles
+        )
+
+    assert not missing
+
+
 def test_drift_loader_preserves_base_first_cluster_contract():
     path = ROOT / "model-development/datasets/benchmarks/trace_driftbench/test.jsonl"
     cluster = load_driftbench(path, n_clusters=1)[0]
diff --git a/ai-service/tests/benchmark/test_runtime_protocols.py b/ai-service/tests/benchmark/test_runtime_protocols.py
index f30328a5..729a6b7a 100644
--- a/ai-service/tests/benchmark/test_runtime_protocols.py
+++ b/ai-service/tests/benchmark/test_runtime_protocols.py
@@ -1,10 +1,11 @@
 import pytest
 
+from api.core.redis_client import RedisClient
 from tracecag_bench.catalog import MODES
 from tracecag_bench.config import BenchmarkConfig
-from tracecag_bench.protocols.public_qa import run_public_qa_protocol
+from tracecag_bench.protocols.public_qa import ircot_summary, run_public_qa_protocol
 from tracecag_bench.runtime.ai_service import AIServiceRuntime, classify_provider
-from tracecag_bench.schemas import ContextDocument, PublicQASample
+from tracecag_bench.schemas import ContextDocument, PublicQASample, RunObservation
 
 
 class FakePipeline:
@@ -49,3 +50,62 @@ async def test_public_protocol_passes_context_docs_and_measures_trace():
 
 def test_provider_classification_keeps_full_qwen_model_name():
     assert classify_provider(["groq/qwen/qwen3-32b"]) == ("groq", "qwen/qwen3-32b", "")
+
+
+def test_redis_client_reads_benchmark_disabled_env(monkeypatch):
+    monkeypatch.setenv("BENCHMARK_REDIS_DISABLED", "true")
+
+    assert RedisClient._benchmark_redis_disabled() is True
+
+
+def test_redis_client_disables_redis_when_benchmark_fail_fast(monkeypatch):
+    monkeypatch.delenv("BENCHMARK_REDIS_DISABLED", raising=False)
+    monkeypatch.setenv("BENCHMARK_REDIS_FAIL_FAST", "true")
+
+    assert RedisClient._benchmark_redis_disabled() is True
+
+
+def test_redis_client_disabled_env_overrides_fail_fast(monkeypatch):
+    monkeypatch.setenv("BENCHMARK_REDIS_DISABLED", "false")
+    monkeypatch.setenv("BENCHMARK_REDIS_FAIL_FAST", "true")
+
+    assert RedisClient._benchmark_redis_disabled() is False
+
+
+def test_ircot_summary_counts_gate_and_contract_outcomes():
+    rows = [
+        {
+            "evaluated": True,
+            "selected": False,
+            "reason": "skip_yes_no",
+        },
+        {
+            "evaluated": True,
+            "selected": True,
+            "reason": "augmented",
+            "reason_latency_ms": 12,
+            "contract": {"passes": True},
+        },
+        {
+            "evaluated": True,
+            "selected": True,
+            "reason": "contract_rejected",
+            "reason_latency_ms": 18,
+            "contract": {"passes": False},
+        },
+    ]
+    summary = ircot_summary([
+        RunObservation(sample_id=f"s{i}", mode="tracecag_rapid", retrieval_meta={"ircot": row})
+        for i, row in enumerate(rows)
+    ])
+
+    assert summary["evaluated"] == 3
+    assert summary["selected"] == 2
+    assert summary["selection_rate"] == pytest.approx(2 / 3)
+    assert summary["reason_counts"] == {
+        "augmented": 1,
+        "contract_rejected": 1,
+        "skip_yes_no": 1,
+    }
+    assert summary["contract_pass_rate"] == 0.5
+    assert summary["avg_reason_latency_ms"] == 15
diff --git a/ai-service/tests/service/test_tracecag_lexilingo_adapter.py b/ai-service/tests/service/test_tracecag_lexilingo_adapter.py
new file mode 100644
index 00000000..b4e8c1bc
--- /dev/null
+++ b/ai-service/tests/service/test_tracecag_lexilingo_adapter.py
@@ -0,0 +1,63 @@
+import pytest
+
+from service.tracecag_service import TraceCAGRequest
+from service.tracecag_service.adapters.lexilingo import LexiLingoTraceCAGAnalyzer
+
+
+class FakePipeline:
+    def __init__(self):
+        self.calls = []
+
+    async def analyze(self, **kwargs):
+        self.calls.append(kwargs)
+        return {
+            "tutor_response": "from existing pipeline",
+            "metadata": {"path": "slow", "cache_hit": False},
+        }
+
+
+@pytest.mark.asyncio
+async def test_lexilingo_adapter_maps_request_to_existing_pipeline_kwargs():
+    pipeline = FakePipeline()
+    adapter = LexiLingoTraceCAGAnalyzer(pipeline_factory=lambda: pipeline)
+    request = TraceCAGRequest(
+        user_input="I go yesterday",
+        session_id="s1",
+        user_id="u1",
+        input_type="text",
+        learner_profile={"level": "A2"},
+        conversation_history=[{"role": "user", "content": "hello"}],
+        kg_seed_concepts=["concept:grammar.past_time_markers"],
+        return_raw_state=True,
+    )
+
+    response = await adapter.analyze(request)
+
+    assert response.tutor_response == "from existing pipeline"
+    assert len(pipeline.calls) == 1
+    call = pipeline.calls[0]
+    assert call["user_input"] == "I go yesterday"
+    assert call["session_id"] == "s1"
+    assert call["user_id"] == "u1"
+    assert call["learner_profile"] == {"level": "A2"}
+    assert call["conversation_history"] == [{"role": "user", "content": "hello"}]
+    assert call["kg_seed_concepts"] == ["concept:grammar.past_time_markers"]
+    assert call["return_raw_state"] is True
+    assert response.raw_state["tutor_response"] == "from existing pipeline"
+
+
+@pytest.mark.asyncio
+async def test_lexilingo_adapter_accepts_async_pipeline_factory():
+    pipeline = FakePipeline()
+
+    async def factory():
+        return pipeline
+
+    adapter = LexiLingoTraceCAGAnalyzer(pipeline_factory=factory)
+
+    response = await adapter.analyze(
+        TraceCAGRequest(user_input="hello", session_id="s1")
+    )
+
+    assert response.tutor_response == "from existing pipeline"
+    assert len(pipeline.calls) == 1
diff --git a/ai-service/tests/service/test_tracecag_memory_adapter.py b/ai-service/tests/service/test_tracecag_memory_adapter.py
new file mode 100644
index 00000000..f81731fc
--- /dev/null
+++ b/ai-service/tests/service/test_tracecag_memory_adapter.py
@@ -0,0 +1,88 @@
+import pytest
+
+from service.tracecag_service import TraceCAGRequest, TraceCAGService
+from service.tracecag_service.adapters.memory import InMemoryTraceCAGAnalyzer
+
+
+@pytest.mark.asyncio
+async def test_memory_adapter_cache_miss_then_l0_reuse():
+    service = TraceCAGService(InMemoryTraceCAGAnalyzer())
+    request = TraceCAGRequest(
+        user_input="Who founded AlphaSoft?",
+        session_id="s1",
+        learner_profile={"level": "B1"},
+    )
+
+    first = await service.analyze(request)
+    second = await service.analyze(request)
+
+    assert first.metadata["cache_hit"] is False
+    assert first.metadata["cache_decision"] == "full"
+    assert second.metadata["cache_hit"] is True
+    assert second.metadata["cache_layer"] == "L0"
+    assert second.metadata["cache_decision"] == "reuse"
+    assert second.tutor_response == first.tutor_response
+
+
+@pytest.mark.asyncio
+async def test_memory_adapter_uses_l1_patch_for_state_compatible_near_hit():
+    service = TraceCAGService(InMemoryTraceCAGAnalyzer())
+
+    await service.analyze(
+        TraceCAGRequest(
+            user_input="Who founded AlphaSoft?",
+            session_id="s1",
+            learner_profile={"level": "B1"},
+        )
+    )
+    response = await service.analyze(
+        TraceCAGRequest(
+            user_input="Who created AlphaSoft?",
+            session_id="s1",
+            learner_profile={"level": "B1"},
+        )
+    )
+
+    assert response.metadata["cache_hit"] is True
+    assert response.metadata["cache_layer"] == "L1"
+    assert response.metadata["cache_decision"] == "patch"
+    assert "State-compatible cache patch" in response.tutor_response
+
+
+@pytest.mark.asyncio
+async def test_memory_adapter_rejects_l1_when_profile_level_changes():
+    service = TraceCAGService(InMemoryTraceCAGAnalyzer())
+
+    await service.analyze(
+        TraceCAGRequest(
+            user_input="Who founded AlphaSoft?",
+            session_id="s1",
+            learner_profile={"level": "B1"},
+        )
+    )
+    response = await service.analyze(
+        TraceCAGRequest(
+            user_input="Who created AlphaSoft?",
+            session_id="s1",
+            learner_profile={"level": "C1"},
+        )
+    )
+
+    assert response.metadata["cache_hit"] is False
+    assert response.metadata["cache_decision"] == "full"
+
+
+@pytest.mark.asyncio
+async def test_memory_adapter_respects_cache_policy_off():
+    service = TraceCAGService(InMemoryTraceCAGAnalyzer())
+    request = TraceCAGRequest(
+        user_input="Who founded AlphaSoft?",
+        session_id="s1",
+        cache_policy="off",
+    )
+
+    first = await service.analyze(request)
+    second = await service.analyze(request)
+
+    assert first.metadata["cache_hit"] is False
+    assert second.metadata["cache_hit"] is False
diff --git a/ai-service/tests/service/test_tracecag_service_runtime.py b/ai-service/tests/service/test_tracecag_service_runtime.py
new file mode 100644
index 00000000..e953857f
--- /dev/null
+++ b/ai-service/tests/service/test_tracecag_service_runtime.py
@@ -0,0 +1,73 @@
+import asyncio
+
+import pytest
+
+from service.tracecag_service import (
+    TraceCAGRequest,
+    TraceCAGResponse,
+    TraceCAGService,
+    TraceCAGServiceConfig,
+)
+
+
+class DictAnalyzer:
+    async def analyze(self, request: TraceCAGRequest):
+        return {
+            "tutor_response": f"handled:{request.user_input}",
+            "metadata": {"path": "slow", "cache_hit": False},
+        }
+
+
+class SlowAnalyzer:
+    async def analyze(self, request: TraceCAGRequest):
+        await asyncio.sleep(0.05)
+        return TraceCAGResponse(tutor_response="too late")
+
+
+@pytest.mark.asyncio
+async def test_runtime_normalizes_mapping_response():
+    service = TraceCAGService(DictAnalyzer())
+
+    response = await service.analyze_text("hello", session_id="s1")
+
+    assert response.tutor_response == "handled:hello"
+    assert response.metadata["path"] == "slow"
+    assert response.metadata["service"]["adapter"] == "DictAnalyzer"
+    assert response.metadata["request"]["session_id"] == "s1"
+
+
+@pytest.mark.asyncio
+async def test_runtime_returns_validation_error_without_calling_adapter():
+    service = TraceCAGService(DictAnalyzer())
+
+    response = await service.analyze(TraceCAGRequest(user_input="", session_id="s1"))
+
+    assert response.error == "user_input is required"
+    assert response.metadata["path"] == "error"
+    assert response.metadata["error_type"] == "validation"
+
+
+@pytest.mark.asyncio
+async def test_runtime_timeout_is_returned_as_response():
+    service = TraceCAGService(
+        SlowAnalyzer(),
+        TraceCAGServiceConfig(timeout_seconds=0.001),
+    )
+
+    response = await service.analyze_text("hello", session_id="s1")
+
+    assert response.error == "TRACE-CAG service timed out"
+    assert response.metadata["error_type"] == "timeout"
+
+
+@pytest.mark.asyncio
+async def test_analyze_many_uses_service_contract():
+    service = TraceCAGService(DictAnalyzer(), TraceCAGServiceConfig(max_concurrency=2))
+    requests = [
+        TraceCAGRequest(user_input="one", session_id="s1"),
+        TraceCAGRequest(user_input="two", session_id="s2"),
+    ]
+
+    responses = await service.analyze_many(requests)
+
+    assert [item.tutor_response for item in responses] == ["handled:one", "handled:two"]
diff --git a/ai-service/tests/stt/test_normalizer.py b/ai-service/tests/stt/test_normalizer.py
new file mode 100644
index 00000000..6944dbd9
--- /dev/null
+++ b/ai-service/tests/stt/test_normalizer.py
@@ -0,0 +1,125 @@
+import pytest
+
+from api.services.stt.transcript_normalizer import normalize_transcript
+
+
+def test_trim_removes_extra_whitespace():
+    text, rules = normalize_transcript("  hello world  ")
+    assert text == "hello world."
+    assert "trim" in rules
+
+
+def test_adds_period_when_missing():
+    text, rules = normalize_transcript("hello world")
+    assert text == "hello world."
+    assert "punctuation" in rules
+
+
+def test_no_change_when_punctuated():
+    text, rules = normalize_transcript("Hello world.")
+    assert text == "Hello world."
+    assert "punctuation" not in rules
+
+
+def test_question_mark_preserved():
+    text, rules = normalize_transcript("What time is it?")
+    assert text == "What time is it?"
+    assert "punctuation" not in rules
+
+
+def test_filler_um_removed():
+    text, rules = normalize_transcript("um")
+    assert text == ""
+    assert rules == ["filler_removed"]
+
+
+def test_filler_uh_removed():
+    text, rules = normalize_transcript("uh")
+    assert text == ""
+    assert rules == ["filler_removed"]
+
+
+def test_filler_hmm_removed():
+    text, rules = normalize_transcript("hmm")
+    assert text == ""
+    assert rules == ["filler_removed"]
+
+
+def test_filler_with_trailing_period_removed():
+    text, rules = normalize_transcript("um.")
+    assert text == ""
+    assert rules == ["filler_removed"]
+
+
+def test_filler_mixed_case_removed():
+    text, rules = normalize_transcript("Uh")
+    assert text == ""
+    assert rules == ["filler_removed"]
+
+
+def test_bigram_repeat_deduplicated():
+    text, rules = normalize_transcript("hello world hello world hello world")
+    assert text == "hello world."
+    assert "deduplication" in rules
+
+
+def test_trigram_repeat_deduplicated():
+    text, rules = normalize_transcript("I want to I want to I want to")
+    assert text == "I want to."
+    assert "deduplication" in rules
+
+
+def test_unigram_repeat_with_tail_deduplicated():
+    text, rules = normalize_transcript("can can can you help me")
+    assert text == "can you help me."
+    assert "deduplication" in rules
+
+
+def test_unigram_repeat_only_collapsed():
+    text, rules = normalize_transcript("the the the")
+    assert text == "the."
+    assert "deduplication" in rules
+
+
+def test_two_repetitions_not_deduplicated():
+    text, rules = normalize_transcript("hello world hello world")
+    assert text == "hello world hello world."
+    assert "deduplication" not in rules
+
+
+def test_normal_sentence_unchanged():
+    text, rules = normalize_transcript("I want to improve my English.")
+    assert text == "I want to improve my English."
+    assert "deduplication" not in rules
+
+
+def test_preserve_exact_skips_filler_removal():
+    text, rules = normalize_transcript("um", preserve_exact=True)
+    assert text == "um"
+    assert "filler_removed" not in rules
+
+
+def test_preserve_exact_skips_punctuation():
+    text, rules = normalize_transcript("hello world", preserve_exact=True)
+    assert text == "hello world"
+    assert "punctuation" not in rules
+
+
+def test_preserve_exact_skips_deduplication():
+    text, rules = normalize_transcript(
+        "hello world hello world hello world", preserve_exact=True
+    )
+    assert text == "hello world hello world hello world"
+    assert "deduplication" not in rules
+
+
+def test_empty_input_returns_empty():
+    text, rules = normalize_transcript("")
+    assert text == ""
+    assert rules == []
+
+
+def test_preserve_exact_still_trims_whitespace():
+    text, rules = normalize_transcript("  hello  ", preserve_exact=True)
+    assert text == "hello"
+    assert "trim" in rules
diff --git a/ai-service/tests/stt/test_pipeline.py b/ai-service/tests/stt/test_pipeline.py
index b9c194a9..4e965697 100644
--- a/ai-service/tests/stt/test_pipeline.py
+++ b/ai-service/tests/stt/test_pipeline.py
@@ -1,9 +1,11 @@
 import pytest
 
 from api.services.stt.config import STTConfig
+from api.services.stt.metrics import STTMetrics
 from api.services.stt.model_registry import STTModelRegistry
 from api.services.stt.schemas import AudioSegment, PrimaryResult, UseCase
 from api.services.stt.sentence_finalizer import SentenceFinalizer
+from api.services.stt.vad_endpointing import EnergyEndpointDetector
 from api.services.stt.verifier_router import VerifierRouter
 from tests.stt.fakes import FakePrimary, FakeVerifier
 
@@ -45,3 +47,84 @@ async def test_finalizer_selects_better_verifier(tmp_path):
     assert event.text == "verified text."
     assert event.verified is True
     assert event.source == "faster-whisper"
+
+
+@pytest.mark.asyncio
+async def test_verifier_failure_marks_uncertain_and_source_only(tmp_path):
+    config = STTConfig(temp_dir=str(tmp_path))
+    registry = STTModelRegistry(
+        config, primary=FakePrimary(), verifier=FakeVerifier(fail=True)
+    )
+    finalizer = SentenceFinalizer(config, registry)
+    audio = AudioSegment(pcm16=b"\x00\x00" * 8000, start_ms=0, end_ms=1000)
+    primary = PrimaryResult(
+        text="hello", confidence=0.5, confidence_source="fake", source="fake-primary"
+    )
+    event = await finalizer.finalize("s1", "t1", UseCase.CONVERSATION, "en", audio, primary)
+    assert event is not None
+    assert event.uncertain is True
+    assert event.source == "fake-primary_only"
+
+
+@pytest.mark.asyncio
+async def test_finalizer_drops_noise_utterance(tmp_path):
+    config = STTConfig(temp_dir=str(tmp_path), verify_enabled=False)
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    finalizer = SentenceFinalizer(config, registry)
+    result = await finalizer.finalize(
+        "s1",
+        "t1",
+        UseCase.CONVERSATION,
+        "en",
+        AudioSegment(pcm16=b"\x00\x00" * 8000, start_ms=0, end_ms=1000),
+        PrimaryResult(text="um", confidence=0.9, confidence_source="fake", source="fake-primary"),
+    )
+    assert result is None
+
+
+def test_router_always_verifies_non_conversation_use_cases(tmp_path):
+    router = VerifierRouter(STTConfig(temp_dir=str(tmp_path)))
+    audio_duration_ms = 2000
+    primary = PrimaryResult(
+        text="hello world", confidence=0.9, confidence_source="fake", source="fake-primary"
+    )
+    for use_case in (UseCase.SPEAKING_PRACTICE, UseCase.PRONUNCIATION_SCORING):
+        decision = router.decide(primary, audio_duration_ms, use_case)
+        assert decision.verify, f"{use_case} should always trigger verification"
+        assert decision.reason == "accuracy_sensitive_use_case"
+
+
+@pytest.mark.asyncio
+async def test_vad_fallback_to_energy_detector(tmp_path):
+    config = STTConfig(
+        temp_dir=str(tmp_path),
+        vad_engine="silero",
+        silero_model_path="/nonexistent/model.onnx",
+    )
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    await registry.start()
+    assert registry.vad_status == "fallback"
+    vad = registry.create_vad()
+    assert isinstance(vad, EnergyEndpointDetector)
+    assert registry.vad_fallback_count == 1
+
+
+@pytest.mark.asyncio
+async def test_metrics_records_verify_latency(tmp_path):
+    config = STTConfig(temp_dir=str(tmp_path))
+    metrics = STTMetrics()
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    finalizer = SentenceFinalizer(config, registry, metrics)
+    await finalizer.finalize(
+        "s1",
+        "t1",
+        UseCase.CONVERSATION,
+        "en",
+        AudioSegment(pcm16=b"\x00\x00" * 8000, start_ms=0, end_ms=1000),
+        PrimaryResult(
+            text="hello", confidence=0.5, confidence_source="fake", source="fake-primary"
+        ),
+    )
+    stats = metrics.latency_stats("stt_verify_latency_ms")
+    assert stats["count"] == 1
+    assert stats["avg"] >= 0
diff --git a/ai-service/tests/stt/test_session_manager.py b/ai-service/tests/stt/test_session_manager.py
index add282de..72100215 100644
--- a/ai-service/tests/stt/test_session_manager.py
+++ b/ai-service/tests/stt/test_session_manager.py
@@ -159,3 +159,22 @@ async def test_cancelled_session_start_releases_reservation(tmp_path):
 
     assert not manager.sessions
     assert not manager._pending_sessions
+
+
+@pytest.mark.asyncio
+async def test_idle_session_is_closed_by_manager(tmp_path):
+    config = STTConfig(temp_dir=str(tmp_path), session_idle_timeout_seconds=0)
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    registry.status = "ready"
+    manager = SessionManager(config, registry)
+
+    session = await manager.create(StartMessage(session_id="idle"))
+    session.last_activity = time.monotonic() - 1.0
+
+    now = time.monotonic()
+    for sid, s in list(manager.sessions.items()):
+        if now - s.last_activity > manager.config.session_idle_timeout_seconds:
+            await manager.close(sid, "idle_timeout")
+
+    assert "idle" not in manager.sessions
+    await manager.shutdown()
diff --git a/ai-service/tests/stt/test_voice_session.py b/ai-service/tests/stt/test_voice_session.py
index 40be17de..ad84eff6 100644
--- a/ai-service/tests/stt/test_voice_session.py
+++ b/ai-service/tests/stt/test_voice_session.py
@@ -206,6 +206,98 @@ async def test_stop_emits_downstream_timeout_before_closing(tmp_path):
     assert events[-2]["error"] == "TRACE-CAG response timed out"
 
 
+@pytest.mark.asyncio
+async def test_silence_frames_produce_no_final(tmp_path):
+    config = STTConfig(
+        temp_dir=str(tmp_path),
+        min_speech_ms=20,
+        min_silence_ms=20,
+        verify_enabled=False,
+    )
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    registry.status = "ready"
+    session = VoiceSession(
+        StartMessage(session_id="silent"), config, registry, STTMetrics()
+    )
+    await session.start_worker()
+    for i in range(5):
+        silence = parse_audio_frame(HEADER.pack(1, 0, i, i * 20) + b"\x00\x00" * 320)
+        session.enqueue(silence)
+    await asyncio.sleep(0.05)
+    await session.stop()
+    events = list(session.event_queue._queue)
+    final_events = [e for e in events if e.get("type") == "stt.final"]
+    assert not final_events
+
+
+@pytest.mark.asyncio
+async def test_metrics_records_time_to_first_partial(tmp_path):
+    config = STTConfig(
+        temp_dir=str(tmp_path),
+        min_speech_ms=20,
+        min_silence_ms=20,
+        verify_enabled=False,
+    )
+    primary_session = FakePrimarySession()
+    registry = STTModelRegistry(
+        config, primary=FakePrimary(primary_session), verifier=FakeVerifier()
+    )
+    registry.status = "ready"
+    metrics = STTMetrics()
+    session = VoiceSession(
+        StartMessage(session_id="partial-metrics"), config, registry, metrics
+    )
+    await session.start_worker()
+    session.enqueue(_speech_frame(0))
+    await asyncio.sleep(0.05)
+    await session.stop()
+    stats = metrics.latency_stats("stt_time_to_first_partial_ms")
+    assert stats["count"] == 1
+    assert stats["avg"] >= 0
+
+
+@pytest.mark.asyncio
+async def test_metrics_records_final_latency(tmp_path):
+    config = STTConfig(
+        temp_dir=str(tmp_path),
+        min_speech_ms=20,
+        min_silence_ms=20,
+        verify_enabled=False,
+    )
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    registry.status = "ready"
+    metrics = STTMetrics()
+    session = VoiceSession(
+        StartMessage(session_id="final-metrics"), config, registry, metrics
+    )
+    await session.start_worker()
+    session.enqueue(_speech_frame(0))
+    silence = parse_audio_frame(HEADER.pack(1, 0, 1, 20) + b"\x00\x00" * 320)
+    session.enqueue(silence)
+    await asyncio.sleep(0.05)
+    await session.stop()
+    stats = metrics.latency_stats("stt_final_latency_ms")
+    assert stats["count"] >= 1
+    assert stats["avg"] >= 0
+
+
+@pytest.mark.asyncio
+async def test_metrics_records_session_duration(tmp_path):
+    config = STTConfig(temp_dir=str(tmp_path))
+    registry = STTModelRegistry(config, primary=FakePrimary(), verifier=FakeVerifier())
+    registry.status = "ready"
+    metrics = STTMetrics()
+    session = VoiceSession(
+        StartMessage(session_id="duration-metrics"), config, registry, metrics
+    )
+    await session.start_worker()
+    await asyncio.sleep(0.01)
+    await session.stop()
+    stats = metrics.latency_stats("stt_session_duration_s")
+    assert stats["count"] == 1
+    assert stats["avg"] >= 0.01
+
+
 @pytest.mark.asyncio
 async def test_stop_timeout_does_not_overwrite_completed_response(tmp_path):
     config = STTConfig(
diff --git a/ai-service/tests/test_dependency_constraints.py b/ai-service/tests/test_dependency_constraints.py
index c33685fe..7f29c1f8 100644
--- a/ai-service/tests/test_dependency_constraints.py
+++ b/ai-service/tests/test_dependency_constraints.py
@@ -24,12 +24,13 @@ def test_ai_constraints_match_supported_torch_stack():
 
     expected = {
         "numpy": "1.26.4",
-        "torch": "2.2.2",
+        "torch": "2.12.1",
         "transformers": "4.57.6",
         "sentence-transformers": "4.1.0",
         "faster-whisper": "1.2.1",
-        "moonshine-voice": "0.0.59",
-        "sherpa-onnx": "1.13.2",
+        "moonshine-voice": "0.0.65",
+        "sherpa-onnx": "1.13.3",
+        "scipy": "1.17.1",
     }
     for package, version in expected.items():
         pinned = constraints[package]
diff --git a/ai-service/tests/test_history_restore_endpoints.py b/ai-service/tests/test_history_restore_endpoints.py
index 661ce6d6..4a13414c 100644
--- a/ai-service/tests/test_history_restore_endpoints.py
+++ b/ai-service/tests/test_history_restore_endpoints.py
@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import UTC, datetime
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
@@ -7,6 +7,7 @@
 from api.routes import chat as chat_route
 from api.routes import lexi_chat as lexi_route
 from api.routes import topic_chat as topic_route
+from api.services import lexi_chat_service as lexi_svc
 from api.core.auth import AuthenticatedUser
 
 
@@ -87,7 +88,7 @@ def mock_lexi_store(monkeypatch):
     store.set_session = AsyncMock()
     store.delete_messages = AsyncMock()
     store.append_message = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_store", store)
+    monkeypatch.setattr(lexi_svc, "lexi_store", store)
     return store
 
 
@@ -99,7 +100,7 @@ async def test_chat_messages_limit_positive_uses_limit_cursor(mock_chat_db):
             {
                 "role": "user",
                 "content": "hello",
-                "timestamp": datetime.utcnow(),
+                "timestamp": datetime.now(UTC),
             }
         ]
     )
@@ -179,7 +180,9 @@ async def test_topic_messages_limit_positive_uses_limit_cursor(mock_topic_db):
 
 
 @pytest.mark.asyncio
-async def test_lexi_messages_returns_cached_when_cache_is_complete(mock_lexi_db, mock_lexi_store):
+async def test_lexi_messages_returns_cached_when_cache_is_complete(
+    mock_lexi_db, mock_lexi_store
+):
     mock_lexi_db["lexi_sessions"].find_one.return_value = {
         "session_id": "lexi_s1",
         "message_count": 2,
@@ -189,8 +192,18 @@ async def test_lexi_messages_returns_cached_when_cache_is_complete(mock_lexi_db,
         "user_id": "u1",
     }
     mock_lexi_store.get_messages.return_value = [
-        {"id": "m1", "role": "user", "content": "hello", "timestamp": "2026-04-16T10:00:00"},
-        {"id": "m2", "role": "assistant", "content": "hi", "timestamp": "2026-04-16T10:00:01"},
+        {
+            "id": "m1",
+            "role": "user",
+            "content": "hello",
+            "timestamp": "2026-04-16T10:00:00",
+        },
+        {
+            "id": "m2",
+            "role": "assistant",
+            "content": "hi",
+            "timestamp": "2026-04-16T10:00:01",
+        },
     ]
 
     result = await lexi_route.get_lexi_messages(
@@ -206,14 +219,21 @@ async def test_lexi_messages_returns_cached_when_cache_is_complete(mock_lexi_db,
 
 
 @pytest.mark.asyncio
-async def test_lexi_messages_uses_cached_payload_when_session_doc_missing(mock_lexi_db, mock_lexi_store):
+async def test_lexi_messages_uses_cached_payload_when_session_doc_missing(
+    mock_lexi_db, mock_lexi_store
+):
     mock_lexi_db["lexi_sessions"].find_one.return_value = None
     mock_lexi_store.get_session.return_value = {
         "session_id": "lexi_s1",
         "user_id": "u1",
     }
     mock_lexi_store.get_messages.return_value = [
-        {"id": "m1", "role": "user", "content": "cached", "timestamp": "2026-04-16T10:00:00"}
+        {
+            "id": "m1",
+            "role": "user",
+            "content": "cached",
+            "timestamp": "2026-04-16T10:00:00",
+        }
     ]
 
     result = await lexi_route.get_lexi_messages(
@@ -229,7 +249,9 @@ async def test_lexi_messages_uses_cached_payload_when_session_doc_missing(mock_l
 
 
 @pytest.mark.asyncio
-async def test_lexi_messages_raises_404_when_no_db_and_no_cache(mock_lexi_db, mock_lexi_store):
+async def test_lexi_messages_raises_404_when_no_db_and_no_cache(
+    mock_lexi_db, mock_lexi_store
+):
     mock_lexi_db["lexi_sessions"].find_one.return_value = None
     mock_lexi_store.get_session.return_value = None
 
diff --git a/ai-service/tests/test_lexi_chat_routes.py b/ai-service/tests/test_lexi_chat_routes.py
index 24791c76..48d8b5ee 100644
--- a/ai-service/tests/test_lexi_chat_routes.py
+++ b/ai-service/tests/test_lexi_chat_routes.py
@@ -9,6 +9,7 @@
 from bson import ObjectId
 
 from api.routes import lexi_chat as lexi_route
+from api.services import lexi_chat_service as svc
 from api.core.auth import AuthenticatedUser
 
 
@@ -45,7 +46,7 @@ def mock_store(monkeypatch):
     store.get_session = AsyncMock(return_value=None)
     store.delete_session = AsyncMock()
     store.delete_messages = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_store", store)
+    monkeypatch.setattr(svc, "lexi_store", store)
     return store
 
 
@@ -54,7 +55,7 @@ def mock_idempotency(monkeypatch):
     idem = MagicMock()
     idem.get = AsyncMock(return_value=None)
     idem.set = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_idempotency_store", idem)
+    monkeypatch.setattr(svc, "lexi_idempotency_store", idem)
     return idem
 
 
@@ -135,7 +136,7 @@ async def test_lexi_chat_returns_response(mock_store, mock_idempotency, monkeypa
     monkeypatch.setattr(lexi_route, "enforce_user_quota", AsyncMock(return_value=_quota()))
     monkeypatch.setattr(lexi_route, "emit_ai_audit_event", AsyncMock())
 
-    pipeline_result = lexi_route._PipelineResult(
+    pipeline_result = svc.PipelineResult(
         lexi_response="Squawk! Great question!",
         user_text="Hello Lexi",
         message_id="msg-1",
@@ -143,7 +144,7 @@ async def test_lexi_chat_returns_response(mock_store, mock_idempotency, monkeypa
         model_used="trace-cag",
         metadata={"pipeline_steps": [], "latency_ms": 100, "quota": {}},
     )
-    monkeypatch.setattr(lexi_route, "_run_lexi_pipeline", AsyncMock(return_value=pipeline_result))
+    monkeypatch.setattr(svc, "run_lexi_pipeline", AsyncMock(return_value=pipeline_result))
 
     db = _make_db()
     request_ctx = MagicMock()
@@ -174,7 +175,7 @@ async def test_lexi_chat_returns_cached_idempotency_response(mock_store, mock_id
     mock_idempotency.get.return_value = cached
 
     run_pipeline = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_run_lexi_pipeline", run_pipeline)
+    monkeypatch.setattr(svc, "run_lexi_pipeline", run_pipeline)
 
     db = _make_db()
     request_ctx = MagicMock()
@@ -192,6 +193,61 @@ async def test_lexi_chat_returns_cached_idempotency_response(mock_store, mock_id
     run_pipeline.assert_not_called()
 
 
+# ─── native_language ──────────────────────────────────────────────────────────
+
+def test_idempotency_request_hash_differs_by_native_language():
+    """Two otherwise-identical requests in different native languages must not
+    collide on the same idempotency key — a Japanese learner's reply shouldn't
+    surface a cached Vietnamese-hint response (or vice versa)."""
+    base = dict(user_id="u1", session_id="s1", message="Hello Lexi")
+    req_vi = svc.LexiChatRequest(**base, native_language="vi")
+    req_ja = svc.LexiChatRequest(**base, native_language="ja")
+
+    assert svc.idempotency_request_hash(req_vi) != svc.idempotency_request_hash(req_ja)
+
+
+def test_lexi_chat_request_defaults_native_language_to_vi():
+    request = lexi_route.LexiChatRequest(user_id="u1", message="Hello")
+    assert request.native_language == "vi"
+
+
+@pytest.mark.asyncio
+async def test_lexi_chat_passes_native_language_into_learner_profile(
+    mock_store, mock_idempotency, monkeypatch
+):
+    """native_language="ja" must reach orchestrator.process as a mapped
+    learner_profile["native_language"] = "Japanese", not the Vietnamese default."""
+    monkeypatch.setattr(lexi_route, "enforce_user_scope", lambda cu, uid: uid)
+    monkeypatch.setattr(lexi_route, "enforce_user_quota", AsyncMock(return_value=_quota()))
+    monkeypatch.setattr(lexi_route, "emit_ai_audit_event", AsyncMock())
+
+    orchestrator = MagicMock()
+    orchestrator.process = AsyncMock(
+        return_value={"tutor_response": "Good job!", "metadata": {}}
+    )
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", AsyncMock(return_value=orchestrator)
+    )
+
+    db = _make_db()
+    request_ctx = MagicMock()
+    request_ctx.headers = {"X-Request-Id": "req-ja"}
+
+    await lexi_route.lexi_chat(
+        request_context=request_ctx,
+        request=lexi_route.LexiChatRequest(
+            user_id="u1", message="Hello Lexi", native_language="ja"
+        ),
+        x_idempotency_key=None,
+        db=db,
+        current_user=_user(),
+    )
+
+    orchestrator.process.assert_awaited_once()
+    learner_profile = orchestrator.process.call_args.kwargs["learner_profile"]
+    assert learner_profile["native_language"] == "Japanese"
+
+
 @pytest.mark.asyncio
 async def test_lexi_chat_uses_hot_cached_session_without_mongo_lookup(
     mock_store,
@@ -207,7 +263,7 @@ async def test_lexi_chat_uses_hot_cached_session_without_mongo_lookup(
     mock_store.get_session.return_value = {"session_id": "s1", "user_id": "u1"}
     mock_store.get_messages.return_value = cached_history
 
-    pipeline_result = lexi_route._PipelineResult(
+    pipeline_result = svc.PipelineResult(
         lexi_response="Fast cached path",
         user_text="Hello again",
         message_id="msg-1",
@@ -216,7 +272,7 @@ async def test_lexi_chat_uses_hot_cached_session_without_mongo_lookup(
         metadata={"pipeline_steps": [], "latency_ms": 50, "quota": {}},
     )
     run_pipeline = AsyncMock(return_value=pipeline_result)
-    monkeypatch.setattr(lexi_route, "_run_lexi_pipeline", run_pipeline)
+    monkeypatch.setattr(svc, "run_lexi_pipeline", run_pipeline)
 
     db = _make_db(session_doc={"session_id": "s1", "user_id": "u1"})
     request_ctx = MagicMock()
@@ -251,7 +307,7 @@ async def test_lexi_chat_quota_exceeded_raises_429(mock_store, monkeypatch):
         AsyncMock(side_effect=HTTPException(status_code=429, detail="quota exceeded")),
     )
     run_pipeline = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_run_lexi_pipeline", run_pipeline)
+    monkeypatch.setattr(svc, "run_lexi_pipeline", run_pipeline)
 
     db = _make_db()
     request_ctx = MagicMock()
@@ -287,7 +343,7 @@ async def test_lexi_chat_rejects_session_owned_by_another_user(
     db = _make_db(session_doc={"session_id": "sess-other", "user_id": "owner-1"})
 
     run_pipeline = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_run_lexi_pipeline", run_pipeline)
+    monkeypatch.setattr(svc, "run_lexi_pipeline", run_pipeline)
 
     request_ctx = MagicMock()
     request_ctx.headers = {}
@@ -328,7 +384,7 @@ async def test_lexi_chat_rejects_unknown_supplied_session_id(
     db = _make_db(session_doc=None)
 
     run_pipeline = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_run_lexi_pipeline", run_pipeline)
+    monkeypatch.setattr(svc, "run_lexi_pipeline", run_pipeline)
 
     request_ctx = MagicMock()
     request_ctx.headers = {}
@@ -419,7 +475,7 @@ async def test_get_lexi_messages_paged_returns_empty_page(monkeypatch):
     """No messages → pagination with empty list and zero count."""
     session_doc = {"session_id": "s1", "user_id": "u1"}
     db = _make_db(session_doc=session_doc, msg_docs=[], count=0)
-    monkeypatch.setattr(lexi_route, "_ensure_session_owner", AsyncMock(return_value=session_doc))
+    monkeypatch.setattr(svc, "ensure_session_owner", AsyncMock(return_value=session_doc))
 
     result = await lexi_route.get_lexi_messages_paged(
         session_id="s1",
@@ -443,7 +499,7 @@ async def test_get_lexi_messages_paged_returns_messages(monkeypatch):
     doc2 = {"id": "m2", "session_id": "s1", "role": "assistant", "content": "Hello!", "timestamp": "2024-01-01T00:00:01", "_id": OID()}
     session_doc = {"session_id": "s1", "user_id": "u1"}
     db = _make_db(session_doc=session_doc, msg_docs=[doc2, doc1], count=2)
-    monkeypatch.setattr(lexi_route, "_ensure_session_owner", AsyncMock(return_value=session_doc))
+    monkeypatch.setattr(svc, "ensure_session_owner", AsyncMock(return_value=session_doc))
 
     result = await lexi_route.get_lexi_messages_paged(
         session_id="s1",
@@ -464,7 +520,7 @@ async def test_get_lexi_messages_paged_invalid_limit_raises_400(monkeypatch):
 
     session_doc = {"session_id": "s1", "user_id": "u1"}
     db = _make_db(session_doc=session_doc)
-    monkeypatch.setattr(lexi_route, "_ensure_session_owner", AsyncMock(return_value=session_doc))
+    monkeypatch.setattr(svc, "ensure_session_owner", AsyncMock(return_value=session_doc))
 
     with pytest.raises(HTTPException) as exc_info:
         await lexi_route.get_lexi_messages_paged(
@@ -485,7 +541,7 @@ async def test_get_lexi_messages_metadata_empty_session(monkeypatch):
     """No messages → all nulls in metadata."""
     session_doc = {"session_id": "s1", "user_id": "u1"}
     db = _make_db(session_doc=session_doc, count=0)
-    monkeypatch.setattr(lexi_route, "_ensure_session_owner", AsyncMock(return_value=session_doc))
+    monkeypatch.setattr(svc, "ensure_session_owner", AsyncMock(return_value=session_doc))
 
     result = await lexi_route.get_lexi_messages_metadata(
         session_id="s1",
@@ -508,7 +564,7 @@ async def test_get_lexi_messages_metadata_with_messages(monkeypatch):
 
     session_doc = {"session_id": "s1", "user_id": "u1"}
     db = _make_db(session_doc=session_doc, count=2)
-    monkeypatch.setattr(lexi_route, "_ensure_session_owner", AsyncMock(return_value=session_doc))
+    monkeypatch.setattr(svc, "ensure_session_owner", AsyncMock(return_value=session_doc))
 
     # Override find to return latest/oldest in the right order per call
     call_count = [0]
diff --git a/ai-service/tests/test_lexi_session_management.py b/ai-service/tests/test_lexi_session_management.py
index c279a8c9..015db322 100644
--- a/ai-service/tests/test_lexi_session_management.py
+++ b/ai-service/tests/test_lexi_session_management.py
@@ -5,6 +5,7 @@
 from starlette.requests import Request
 
 from api.routes import lexi_chat as lexi_route
+from api.services import lexi_chat_service as svc
 from api.core.auth import AuthenticatedUser
 
 
@@ -19,7 +20,7 @@ def mock_store(monkeypatch):
     store.get_session = AsyncMock(return_value=None)
     store.delete_session = AsyncMock()
     store.init_messages = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_store", store)
+    monkeypatch.setattr(svc, "lexi_store", store)
     return store
 
 
@@ -204,7 +205,7 @@ async def test_delete_lexi_session_cleans_db_and_cache(mock_db, mock_store):
 
 def test_sanitize_lexi_response_preserves_valid_bold_markdown():
     text = "Ah, a **wonderful** question!"
-    sanitized = lexi_route._sanitize_lexi_response(text)
+    sanitized = svc._sanitize_lexi_response(text)
 
     assert sanitized == text
 
@@ -216,7 +217,7 @@ def test_sanitize_lexi_response_fixes_misaligned_bold_markers():
         "3. Keep **good** habits"
     )
 
-    sanitized = lexi_route._sanitize_lexi_response(raw)
+    sanitized = svc._sanitize_lexi_response(raw)
 
     assert "Daily practice**" not in sanitized
     assert "(15 mins), **" not in sanitized
@@ -324,7 +325,7 @@ def test_sanitize_lexi_response_fixes_escaped_misaligned_bold_markers():
         "3. Keep \\*\\*good\\*\\* habits"
     )
 
-    sanitized = lexi_route._sanitize_lexi_response(raw)
+    sanitized = svc._sanitize_lexi_response(raw)
 
     assert "Daily practice**" not in sanitized
     assert "(15 mins), **" not in sanitized
diff --git a/ai-service/tests/test_tracecag_chat_integration.py b/ai-service/tests/test_tracecag_chat_integration.py
index f2acd576..afa82737 100644
--- a/ai-service/tests/test_tracecag_chat_integration.py
+++ b/ai-service/tests/test_tracecag_chat_integration.py
@@ -1,9 +1,11 @@
-import pytest
 from unittest.mock import AsyncMock, MagicMock
-from datetime import datetime
+from datetime import UTC, datetime
+
+import pytest
 
 from api.routes import chat as chat_route
 from api.routes import lexi_chat as lexi_route
+from api.services import lexi_chat_service as svc
 
 
 @pytest.fixture
@@ -11,7 +13,9 @@ def mock_chat_db():
     db = MagicMock()
 
     chat_sessions = MagicMock()
-    chat_sessions.find_one = AsyncMock(return_value={"session_id": "s1", "user_id": "u1"})
+    chat_sessions.find_one = AsyncMock(
+        return_value={"session_id": "s1", "user_id": "u1"}
+    )
     chat_sessions.update_one = AsyncMock()
 
     chat_messages = MagicMock()
@@ -71,7 +75,7 @@ def mock_lexi_store(monkeypatch):
     store.get_session = AsyncMock(return_value=None)
     store.delete_session = AsyncMock()
     store.init_messages = AsyncMock()
-    monkeypatch.setattr(lexi_route, "_store", store)
+    monkeypatch.setattr(svc, "lexi_store", store)
     quota_mock = MagicMock()
     quota_mock.rpm_used = 1
     quota_mock.rpm_limit = 100
@@ -81,7 +85,9 @@ def mock_lexi_store(monkeypatch):
     quota_mock.tpm_limit = 50000
     quota_mock.tpd_used = 1000
     quota_mock.tpd_limit = 1000000
-    monkeypatch.setattr("api.routes.lexi_chat.enforce_user_quota", AsyncMock(return_value=quota_mock))
+    monkeypatch.setattr(
+        "api.routes.lexi_chat.enforce_user_quota", AsyncMock(return_value=quota_mock)
+    )
     monkeypatch.setattr("api.core.redis_client.RedisClient.get_instance", AsyncMock())
     return store
 
@@ -99,7 +105,9 @@ async def test_chat_send_message_trace_cag_primary_success(monkeypatch, mock_cha
     async def _fake_get_orchestrator():
         return orchestrator
 
-    monkeypatch.setattr("api.services.orchestrator.get_orchestrator", _fake_get_orchestrator)
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
 
     response = await chat_route.send_message(
         chat_route.SendMessageRequest(session_id="s1", user_id="u1", message="Hello"),
@@ -110,7 +118,9 @@ async def _fake_get_orchestrator():
     assert response.metadata["model_used"] == "groq/qwen3-32b"
     assert response.metadata["trace-cag"]["path"] == "trace-cag"
     assert mock_chat_db["chat_messages"].insert_one.await_count == 2
-    mock_chat_db["chat_messages"].find.return_value.sort.assert_called_with("timestamp", -1)
+    mock_chat_db["chat_messages"].find.return_value.sort.assert_called_with(
+        "timestamp", -1
+    )
 
     ai_doc = mock_chat_db["chat_messages"].insert_one.await_args_list[1].args[0]
     assert ai_doc["role"] == "assistant"
@@ -128,12 +138,12 @@ async def test_chat_get_session_messages_limit_zero_returns_full_history(mock_ch
                 {
                     "role": "user",
                     "content": "hello",
-                    "timestamp": datetime.utcnow(),
+                    "timestamp": datetime.now(UTC),
                 },
                 {
                     "role": "assistant",
                     "content": "hi",
-                    "timestamp": datetime.utcnow(),
+                    "timestamp": datetime.now(UTC),
                 },
             ],
             [],
@@ -153,14 +163,19 @@ async def test_chat_get_session_messages_limit_zero_returns_full_history(mock_ch
 
 
 @pytest.mark.asyncio
-async def test_chat_send_message_trace_cag_degraded_retry_success(monkeypatch, mock_chat_db):
+async def test_chat_send_message_trace_cag_degraded_retry_success(
+    monkeypatch, mock_chat_db
+):
     orchestrator = MagicMock()
     orchestrator.process = AsyncMock(
         side_effect=[
             RuntimeError("primary graph failure"),
             {
                 "tutor_response": "TraceCAG degraded retry response",
-                "metadata": {"models_used": ["groq/qwen3-retry"], "path": "trace-cag_degraded"},
+                "metadata": {
+                    "models_used": ["groq/qwen3-retry"],
+                    "path": "trace-cag_degraded",
+                },
             },
         ]
     )
@@ -168,10 +183,14 @@ async def test_chat_send_message_trace_cag_degraded_retry_success(monkeypatch, m
     async def _fake_get_orchestrator():
         return orchestrator
 
-    monkeypatch.setattr("api.services.orchestrator.get_orchestrator", _fake_get_orchestrator)
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
 
     response = await chat_route.send_message(
-        chat_route.SendMessageRequest(session_id="s1", user_id="u1", message="Need fallback"),
+        chat_route.SendMessageRequest(
+            session_id="s1", user_id="u1", message="Need fallback"
+        ),
         db=mock_chat_db,
     )
 
@@ -183,7 +202,9 @@ async def _fake_get_orchestrator():
 
 
 @pytest.mark.asyncio
-async def test_chat_send_message_trace_cag_hard_failure_uses_safe_response(monkeypatch, mock_chat_db):
+async def test_chat_send_message_trace_cag_hard_failure_uses_safe_response(
+    monkeypatch, mock_chat_db
+):
     orchestrator = MagicMock()
     orchestrator.process = AsyncMock(
         side_effect=[
@@ -195,10 +216,14 @@ async def test_chat_send_message_trace_cag_hard_failure_uses_safe_response(monke
     async def _fake_get_orchestrator():
         return orchestrator
 
-    monkeypatch.setattr("api.services.orchestrator.get_orchestrator", _fake_get_orchestrator)
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
 
     response = await chat_route.send_message(
-        chat_route.SendMessageRequest(session_id="s1", user_id="u1", message="Need safe response"),
+        chat_route.SendMessageRequest(
+            session_id="s1", user_id="u1", message="Need safe response"
+        ),
         db=mock_chat_db,
     )
 
@@ -214,8 +239,12 @@ async def test_lexi_chat_voice_uses_stt_trace_cag_and_tts(
     mock_lexi_db,
     mock_lexi_store,
 ):
-    monkeypatch.setattr(lexi_route, "_transcribe_audio", AsyncMock(return_value="Transcribed from voice"))
-    monkeypatch.setattr(lexi_route, "_synthesize_tts", AsyncMock(return_value="FAKE_AUDIO_BASE64"))
+    monkeypatch.setattr(
+        svc, "_transcribe_audio", AsyncMock(return_value="Transcribed from voice")
+    )
+    monkeypatch.setattr(
+        svc, "_synthesize_tts", AsyncMock(return_value="FAKE_AUDIO_BASE64")
+    )
 
     orchestrator = MagicMock()
     orchestrator.process = AsyncMock(
@@ -230,7 +259,9 @@ async def test_lexi_chat_voice_uses_stt_trace_cag_and_tts(
     async def _fake_get_orchestrator():
         return orchestrator
 
-    monkeypatch.setattr("api.services.orchestrator.get_orchestrator", _fake_get_orchestrator)
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
 
     response = await lexi_route.lexi_chat(
         request_context=MagicMock(),
@@ -258,13 +289,52 @@ async def _fake_get_orchestrator():
     assert first_user_msg["content"] == "Transcribed from voice"
 
 
+@pytest.mark.asyncio
+async def test_lexi_chat_native_language_ja_maps_to_japanese_in_learner_profile(
+    monkeypatch,
+    mock_lexi_db,
+    mock_lexi_store,
+):
+    """A Japanese learner's request must reach orchestrator.process with
+    learner_profile["native_language"] == "Japanese", not the Vietnamese
+    default — and the cache must not be shared across languages."""
+    orchestrator = MagicMock()
+    orchestrator.process = AsyncMock(
+        return_value={"tutor_response": "Good job!", "metadata": {}}
+    )
+
+    async def _fake_get_orchestrator():
+        return orchestrator
+
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
+
+    await lexi_route.lexi_chat(
+        request_context=MagicMock(),
+        request=lexi_route.LexiChatRequest(
+            user_id="u1",
+            message="text input",
+            learner_level="B1",
+            native_language="ja",
+        ),
+        db=mock_lexi_db,
+        current_user=MagicMock(user_id="u1"),
+    )
+
+    learner_profile = orchestrator.process.call_args.kwargs["learner_profile"]
+    assert learner_profile["native_language"] == "Japanese"
+
+
 @pytest.mark.asyncio
 async def test_lexi_chat_trace_cag_primary_fail_then_degraded_retry_with_tts(
     monkeypatch,
     mock_lexi_db,
     mock_lexi_store,
 ):
-    monkeypatch.setattr(lexi_route, "_synthesize_tts", AsyncMock(return_value="FAKE_AUDIO_BASE64"))
+    monkeypatch.setattr(
+        svc, "_synthesize_tts", AsyncMock(return_value="FAKE_AUDIO_BASE64")
+    )
 
     orchestrator = MagicMock()
     orchestrator.process = AsyncMock(
@@ -272,7 +342,10 @@ async def test_lexi_chat_trace_cag_primary_fail_then_degraded_retry_with_tts(
             RuntimeError("primary graph failure"),
             {
                 "tutor_response": "Lexi response from degraded TraceCAG",
-                "metadata": {"models_used": ["groq/qwen3-retry"], "path": "trace-cag_degraded"},
+                "metadata": {
+                    "models_used": ["groq/qwen3-retry"],
+                    "path": "trace-cag_degraded",
+                },
             },
         ]
     )
@@ -280,7 +353,9 @@ async def test_lexi_chat_trace_cag_primary_fail_then_degraded_retry_with_tts(
     async def _fake_get_orchestrator():
         return orchestrator
 
-    monkeypatch.setattr("api.services.orchestrator.get_orchestrator", _fake_get_orchestrator)
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
 
     response = await lexi_route.lexi_chat(
         request_context=MagicMock(),
@@ -290,6 +365,7 @@ async def _fake_get_orchestrator():
             input_type="text",
             enable_tts=True,
             learner_level="B1",
+            native_language="ja",
         ),
         db=mock_lexi_db,
         current_user=MagicMock(user_id="u1"),
@@ -303,6 +379,12 @@ async def _fake_get_orchestrator():
     assert response.metadata["trace-cag_metadata"]["fallback_used"] is True
     assert response.metadata["trace-cag_metadata"]["retry_mode"] == "trace-cag_degraded"
 
+    # native_language must survive into the degraded retry call too.
+    retry_learner_profile = orchestrator.process.await_args_list[1].kwargs[
+        "learner_profile"
+    ]
+    assert retry_learner_profile["native_language"] == "Japanese"
+
 
 @pytest.mark.asyncio
 async def test_lexi_chat_tts_timeout_returns_text_without_audio(
@@ -316,7 +398,7 @@ async def _stalled_tts(_text):
         await asyncio.Event().wait()
 
     monkeypatch.setenv("LEXI_TTS_TIMEOUT_SECONDS", "0.01")
-    monkeypatch.setattr(lexi_route, "_synthesize_tts", _stalled_tts)
+    monkeypatch.setattr(svc, "_synthesize_tts", _stalled_tts)
 
     orchestrator = MagicMock()
     orchestrator.process = AsyncMock(
@@ -329,7 +411,9 @@ async def _stalled_tts(_text):
     async def _fake_get_orchestrator():
         return orchestrator
 
-    monkeypatch.setattr("api.services.orchestrator.get_orchestrator", _fake_get_orchestrator)
+    monkeypatch.setattr(
+        "api.services.orchestrator.get_orchestrator", _fake_get_orchestrator
+    )
 
     response = await lexi_route.lexi_chat(
         request_context=MagicMock(),
diff --git a/ai-service/tests/test_translate_routes.py b/ai-service/tests/test_translate_routes.py
index 233868e5..a074fec6 100644
--- a/ai-service/tests/test_translate_routes.py
+++ b/ai-service/tests/test_translate_routes.py
@@ -82,9 +82,9 @@ async def test_groq_primary_path(self):
         mock_resp.status_code = 200
         mock_resp.json.return_value = groq_payload
 
-        with patch("api.routes.translate.get_available_groq_key", new_callable=AsyncMock, return_value="gsk_test"), \
-             patch("api.routes.translate.record_groq_key_usage", new_callable=AsyncMock), \
-             patch("api.routes.translate._throttled_post_json", new_callable=AsyncMock, return_value=mock_resp):
+        with patch("api.core.groq_key_pool.get_available_groq_key", new_callable=AsyncMock, return_value="gsk_test"), \
+             patch("api.core.groq_key_pool.record_groq_key_usage", new_callable=AsyncMock), \
+             patch("api.services.trace_cag.llm_client._throttled_post_json", new_callable=AsyncMock, return_value=mock_resp):
 
             from api.routes.translate import translate_word
             result = await translate_word(word="run", lang="vi", context="She wants to run a company")
@@ -103,8 +103,8 @@ async def test_ollama_fallback_when_groq_unavailable(self):
         mock_ollama.health_check = AsyncMock(return_value=True)
         mock_ollama.chat = AsyncMock(return_value=ollama_raw)
 
-        with patch("api.routes.translate.get_available_groq_key", new_callable=AsyncMock, return_value=None), \
-             patch("api.routes.translate.get_ollama_service", return_value=mock_ollama):
+        with patch("api.core.groq_key_pool.get_available_groq_key", new_callable=AsyncMock, return_value=None), \
+             patch("api.services.ollama_service.get_ollama_service", return_value=mock_ollama):
 
             from api.routes.translate import translate_word
             result = await translate_word(word="run", lang="vi", context="")
@@ -115,8 +115,8 @@ async def test_ollama_fallback_when_groq_unavailable(self):
     @pytest.mark.asyncio
     async def test_empty_result_when_both_fail(self):
         """All backends fail → empty fields returned, no exception raised."""
-        with patch("api.routes.translate.get_available_groq_key", new_callable=AsyncMock, return_value=None), \
-             patch("api.routes.translate.get_ollama_service", side_effect=Exception("Ollama down")):
+        with patch("api.core.groq_key_pool.get_available_groq_key", new_callable=AsyncMock, return_value=None), \
+             patch("api.services.ollama_service.get_ollama_service", side_effect=Exception("Ollama down")):
 
             from api.routes.translate import translate_word
             result = await translate_word(word="run", lang="vi", context="")
@@ -136,9 +136,9 @@ async def test_word_lowercased(self):
             "usage": {"total_tokens": 80},
         }
 
-        with patch("api.routes.translate.get_available_groq_key", new_callable=AsyncMock, return_value="gsk_test"), \
-             patch("api.routes.translate.record_groq_key_usage", new_callable=AsyncMock), \
-             patch("api.routes.translate._throttled_post_json", new_callable=AsyncMock, return_value=mock_resp):
+        with patch("api.core.groq_key_pool.get_available_groq_key", new_callable=AsyncMock, return_value="gsk_test"), \
+             patch("api.core.groq_key_pool.record_groq_key_usage", new_callable=AsyncMock), \
+             patch("api.services.trace_cag.llm_client._throttled_post_json", new_callable=AsyncMock, return_value=mock_resp):
 
             from api.routes.translate import translate_word
             result = await translate_word(word="RUN", lang="vi", context="")
@@ -151,8 +151,8 @@ async def test_ollama_skipped_when_unhealthy(self):
         mock_ollama = AsyncMock()
         mock_ollama.health_check = AsyncMock(return_value=False)
 
-        with patch("api.routes.translate.get_available_groq_key", new_callable=AsyncMock, return_value=None), \
-             patch("api.routes.translate.get_ollama_service", return_value=mock_ollama):
+        with patch("api.core.groq_key_pool.get_available_groq_key", new_callable=AsyncMock, return_value=None), \
+             patch("api.services.ollama_service.get_ollama_service", return_value=mock_ollama):
 
             from api.routes.translate import translate_word
             result = await translate_word(word="bank", lang="vi", context="")
diff --git a/ai-service/tests/trace_cag/test_benchmark_ircot.py b/ai-service/tests/trace_cag/test_benchmark_ircot.py
new file mode 100644
index 00000000..9cb44b38
--- /dev/null
+++ b/ai-service/tests/trace_cag/test_benchmark_ircot.py
@@ -0,0 +1,129 @@
+import time
+
+import pytest
+
+from api.services.trace_cag.benchmark import qa_generation
+from api.services.trace_cag.benchmark.qa_generation import (
+    _generate_benchmark_qa_response,
+    _ircot_augment,
+    _ircot_pick_bridge_passages,
+    _ircot_should_run,
+)
+
+
+def _state(question_docs=None, supporting_titles=None):
+    docs = question_docs or [
+        {"title": "Seed Page", "text": "Seed Page mentions Bridge Target."},
+        {"title": "Bridge Target", "text": "Bridge Target was founded in Khazan."},
+    ]
+    return {
+        "benchmark_task": "multihop_qa",
+        "benchmark_metadata": {
+            "context_docs": docs,
+            "supporting_titles": supporting_titles or ["Seed Page", "Bridge Target"],
+        },
+    }
+
+
+def test_ircot_gate_skips_yes_no_by_default(monkeypatch):
+    monkeypatch.delenv("TRACECAG_BENCHMARK_IRCOT_SELECTIVE", raising=False)
+    monkeypatch.delenv("TRACECAG_IRCOT_SKIP_YES_NO", raising=False)
+
+    selected, meta = _ircot_should_run(
+        "Was the director of Seed Page born in Bridge Target?",
+        "[Seed Page] Seed Page mentions Bridge Target.",
+        _state(),
+    )
+
+    assert selected is False
+    assert meta["reason"] == "skip_yes_no"
+    assert meta["question_type"] == "yes_no"
+
+
+def test_ircot_gate_skips_single_support_samples(monkeypatch):
+    monkeypatch.delenv("TRACECAG_BENCHMARK_IRCOT_SELECTIVE", raising=False)
+
+    selected, meta = _ircot_should_run(
+        "Who founded Bridge Target?",
+        "[Bridge Target] Bridge Target was founded in Khazan.",
+        _state(supporting_titles=["Bridge Target"]),
+    )
+
+    assert selected is False
+    assert meta["reason"] == "skip_single_support"
+
+
+def test_ircot_gate_selects_bridge_multihop(monkeypatch):
+    monkeypatch.delenv("TRACECAG_BENCHMARK_IRCOT_SELECTIVE", raising=False)
+
+    selected, meta = _ircot_should_run(
+        "What city founded the organization that Seed Page mentions?",
+        "[Seed Page] Seed Page mentions Bridge Target.",
+        _state(),
+    )
+
+    assert selected is True
+    assert meta["reason"] in {"missing_support_bridge", "support_titles_multihop", "question_shape_multihop"}
+    assert meta["support_coverage"] < 1.0
+
+
+def test_ircot_bridge_selection_prefers_entity_title_and_excludes_existing():
+    docs = [
+        {"title": "Seed Page", "text": "Seed Page mentions Bridge Target."},
+        {"title": "Distractor", "text": "Bridge Target is mentioned in passing."},
+        {"title": "Bridge Target", "text": "Bridge Target was founded in Khazan."},
+    ]
+
+    picked = _ircot_pick_bridge_passages("Bridge Target", docs, {"seed page"}, k=2)
+
+    assert [doc["title"] for doc in picked] == ["Bridge Target", "Distractor"]
+
+
+@pytest.mark.asyncio
+async def test_ircot_augment_returns_contract_telemetry(monkeypatch):
+    async def fake_reason_call(messages, max_tokens, *, estimated_tokens=96):
+        return "Bridge Target", "groq/qwen/qwen3-32b"
+
+    monkeypatch.setattr(qa_generation, "_groq_chat_with_retry", fake_reason_call)
+
+    context, hint, meta = await _ircot_augment(
+        "What city founded the organization that Seed Page mentions?",
+        "[Seed Page] Seed Page mentions Bridge Target.",
+        _state(),
+    )
+
+    assert context.startswith("[Bridge Target]")
+    assert hint == "Bridge Target"
+    assert meta["bridge_entity"] == "Bridge Target"
+    assert meta["reason_model"] == "groq/qwen/qwen3-32b"
+    assert meta["added_titles"] == ["Bridge Target"]
+    assert meta["contract"]["passes"] is True
+    assert isinstance(meta["reason_latency_ms"], int)
+
+
+@pytest.mark.asyncio
+async def test_benchmark_response_exposes_ircot_metadata_and_reason_model(monkeypatch):
+    async def fake_reason_call(messages, max_tokens, *, estimated_tokens=96):
+        return "Bridge Target", "groq/qwen/qwen3-32b"
+
+    monkeypatch.setattr(qa_generation, "_groq_chat_with_retry", fake_reason_call)
+    monkeypatch.setattr(qa_generation, "_benchmark_provider_order", lambda: [])
+
+    state = _state()
+    state.update(
+        {
+            "user_input": "What city founded the organization that Seed Page mentions?",
+            "retrieved_context": "[Seed Page] Seed Page mentions Bridge Target.",
+            "generation_policy": "auto",
+            "cache_policy": "off",
+            "retrieval_trace": [],
+        }
+    )
+
+    result = await _generate_benchmark_qa_response(state, time.time())
+
+    ircot_meta = result["retrieval_meta"]["ircot"]
+    assert ircot_meta["selected"] is True
+    assert ircot_meta["bridge_entity"] == "Bridge Target"
+    assert "ircot_reason:groq/qwen/qwen3-32b" in result["models_used"]
+    assert result["models_used"][-1] == "extractive_fallback"
diff --git a/ai-service/tests/trace_cag/test_benchmark_model_strength.py b/ai-service/tests/trace_cag/test_benchmark_model_strength.py
new file mode 100644
index 00000000..7ea9a7ba
--- /dev/null
+++ b/ai-service/tests/trace_cag/test_benchmark_model_strength.py
@@ -0,0 +1,38 @@
+"""Regression test for benchmark model-strength classification (Bug 9).
+
+The old substring-tag logic mis-read "groq/qwen/qwen3-32b" as WEAK and
+"qwen3-1.7b" as STRONG ("7b" ⊂ "1.7b") — exactly backwards — so the main
+32B benchmark model got the aggressive extractive override of its answers.
+"""
+
+from api.services.trace_cag.benchmark.qa_generation import _is_strong_benchmark_model
+
+
+def test_qwen3_32b_is_strong():
+    assert _is_strong_benchmark_model("groq/qwen/qwen3-32b") is True
+
+
+def test_qwen3_1_7b_is_weak():
+    # "7b" is a substring of "1.7b" — must NOT classify the 1.7B model as strong.
+    assert _is_strong_benchmark_model("ollama/lexilingo-qwen3-1.7b") is False
+
+
+def test_cloud_models_are_strong():
+    assert _is_strong_benchmark_model("gemini-2.0-flash") is True
+
+
+def test_small_instant_model_is_weak():
+    assert _is_strong_benchmark_model("groq/llama-3.1-8b-instant") is False
+
+
+def test_large_llama_is_strong():
+    assert _is_strong_benchmark_model("groq/llama-3.1-70b-versatile") is True
+
+
+def test_extractive_paths_never_strong():
+    assert _is_strong_benchmark_model("extractive_fallback") is False
+    assert _is_strong_benchmark_model("extractive_policy") is False
+
+
+def test_empty_model_is_weak():
+    assert _is_strong_benchmark_model("") is False
diff --git a/ai-service/tests/trace_cag/test_cache_gate_benchmark_metadata.py b/ai-service/tests/trace_cag/test_cache_gate_benchmark_metadata.py
index f5ee4e22..c75fb58a 100644
--- a/ai-service/tests/trace_cag/test_cache_gate_benchmark_metadata.py
+++ b/ai-service/tests/trace_cag/test_cache_gate_benchmark_metadata.py
@@ -1,4 +1,5 @@
 import hashlib
+import logging
 import time
 
 import pytest
@@ -66,3 +67,20 @@ async def no_candidates(_bucket):
     assert result["cache_decision"] == "full"
     assert result["cache_gate_meta"]["pcc_passed"] is False
     assert "evidence_mismatch" in result["cache_gate_meta"]["reasons"]
+
+
+@pytest.mark.asyncio
+async def test_input_node_skips_redis_warning_when_benchmark_redis_disabled(
+    monkeypatch,
+    caplog,
+):
+    monkeypatch.setenv("BENCHMARK_REDIS_DISABLED", "true")
+    caplog.set_level(logging.WARNING, logger="api.services.trace_cag.nodes_v2")
+
+    result = await nodes.input_node({
+        "user_input": "What verb collocates with decision?",
+        "learner_profile": {"level": "B1"},
+    })
+
+    assert result["learner_profile"] == {"level": "B1"}
+    assert "Redis unavailable" not in caplog.text
diff --git a/ai-service/tests/trace_cag/test_cache_gate_l1.py b/ai-service/tests/trace_cag/test_cache_gate_l1.py
index ba21ad73..3af73deb 100644
--- a/ai-service/tests/trace_cag/test_cache_gate_l1.py
+++ b/ai-service/tests/trace_cag/test_cache_gate_l1.py
@@ -16,7 +16,7 @@ async def test_cache_gate_l1_near_hit_accepts_cache_entry_dict(monkeypatch):
     candidate_input = "I went to school yesterday."
     level = "B1"
     profile = {"level": level}
-    now = time.monotonic()
+    now = time.time()
 
     current_key = hashlib.md5(f"{user_input.lower()}||{level}".encode()).hexdigest()
     candidate_key = hashlib.md5(f"{candidate_input.lower()}||{level}".encode()).hexdigest()
@@ -87,7 +87,7 @@ async def test_cache_gate_l1_patches_safe_qa_paraphrase(monkeypatch):
     candidate_input = "Who was the founder of the corporation behind the iPhone?"
     level = "B1"
     profile = {"level": level}
-    now = time.monotonic()
+    now = time.time()
 
     current_key = hashlib.md5(f"{user_input.lower()}||{level}".encode()).hexdigest()
     candidate_key = hashlib.md5(f"{candidate_input.lower()}||{level}".encode()).hexdigest()
@@ -150,7 +150,7 @@ async def test_cache_gate_l1_rejects_answer_target_shift(monkeypatch):
     candidate_input = "Who was the founder of the corporation behind the iPhone?"
     level = "B1"
     profile = {"level": level}
-    now = time.monotonic()
+    now = time.time()
 
     current_key = hashlib.md5(f"{user_input.lower()}||{level}".encode()).hexdigest()
     candidate_key = hashlib.md5(f"{candidate_input.lower()}||{level}".encode()).hexdigest()
@@ -204,3 +204,109 @@ async def fake_get_bucket_candidate_keys(_bucket):
     assert result["cache_hit"] is False
     assert result["cache_layer"] == "none"
     assert result["cache_decision"] == "full"
+
+
+@pytest.mark.asyncio
+async def test_cache_gate_l0_rejects_reuse_across_native_languages(monkeypatch):
+    """A Vietnamese-hint cache entry must not be reused for a Japanese learner
+    asking the identical question at the identical level — same L0 cache_key,
+    different native_language must still force a full pipeline run."""
+    user_input = "She buy a car yesterday and is happy about it now."
+    level = "B1"
+
+    await cache_mod._write_cache_entry(
+        state={
+            "user_input": user_input,
+            "learner_profile": {"level": level, "native_language": "Vietnamese"},
+            "conversation_history": [],
+        },
+        response="Cached Vietnamese-hint response.",
+        strategy="feedback",
+        errors=[],
+        overall_score=0.9,
+    )
+
+    result = await nodes.cache_gate_node(
+        {
+            "user_input": user_input,
+            "session_id": "test-session",
+            "learner_profile": {"level": level, "native_language": "Japanese"},
+            "conversation_history": [],
+            "cache_policy": "on",
+        }
+    )
+
+    assert result["cache_hit"] is False
+    assert result["cache_decision"] == "full"
+
+
+@pytest.mark.asyncio
+async def test_cache_gate_l1_rejects_near_hit_across_native_languages(monkeypatch):
+    """An L1 near-hit candidate in a different native language must be
+    rejected even when level/intent/concepts all match."""
+    user_input = "I go to school yesterday."
+    candidate_input = "I went to school yesterday."
+    level = "B1"
+    profile = {"level": level, "native_language": "Japanese"}
+    now = time.time()
+
+    current_key = hashlib.md5(f"{user_input.lower()}||{level}".encode()).hexdigest()
+    candidate_key = hashlib.md5(f"{candidate_input.lower()}||{level}".encode()).hexdigest()
+    profile_epoch = nodes._profile_epoch(profile)
+    bucket = nodes._build_graph_bucket(
+        user_input,
+        level,
+        nodes._infer_intent_pre_diagnosis(user_input),
+        profile_epoch,
+        [],
+    )
+    entry = {
+        "fingerprint": {
+            "query_norm": candidate_input.lower(),
+            "intent": "correct",
+            "level": level,
+            "native_language": "Vietnamese",
+            "root_concepts": nodes._extract_lightweight_graph_concepts(user_input),
+            "session_turn": 0,
+        },
+        "graph_bucket": bucket,
+        "profile_snapshot": {"level": level, "native_language": "Vietnamese"},
+        "response": "Cached Vietnamese-hint feedback.",
+        "evidence_bundle": [],
+        "retrieval_trace": [],
+        "execution_plan": {"strategy": "feedback", "intent": "correct"},
+        "diagnosis_errors": [],
+        "grammar_score": 0.9,
+        "fluency_score": 0.9,
+        "vocabulary_level": level,
+        "action_plan": [],
+        "overall_score": 0.9,
+        "created_at": now,
+        "ttl": 3600,
+    }
+
+    async def fake_get_cache_entry(cache_key, _level, _now):
+        if cache_key == current_key:
+            return None
+        if cache_key == candidate_key:
+            return entry
+        raise AssertionError(f"unexpected cache key: {cache_key}")
+
+    async def fake_get_bucket_candidate_keys(_bucket):
+        return [candidate_key] if _bucket == bucket else []
+
+    monkeypatch.setattr(cache_mod, "_get_cache_entry", fake_get_cache_entry)
+    monkeypatch.setattr(cache_mod, "_get_bucket_candidate_keys", fake_get_bucket_candidate_keys)
+
+    result = await nodes.cache_gate_node(
+        {
+            "user_input": user_input,
+            "session_id": "test-session",
+            "learner_profile": profile,
+            "conversation_history": [],
+            "cache_policy": "on",
+        }
+    )
+
+    assert result["cache_hit"] is False
+    assert result["cache_decision"] == "full"
diff --git a/ai-service/tests/trace_cag/test_l1_drift_probe_decisions.py b/ai-service/tests/trace_cag/test_l1_drift_probe_decisions.py
index 2e15d74e..71659b21 100644
--- a/ai-service/tests/trace_cag/test_l1_drift_probe_decisions.py
+++ b/ai-service/tests/trace_cag/test_l1_drift_probe_decisions.py
@@ -55,7 +55,7 @@ def _candidate(
         answer_target=answer_target,
         relation_hints=relations,
         evidence_hash="",
-        created_at=time.monotonic(),
+        created_at=time.time(),
         ttl=3600,
     )
 
diff --git a/ai-service/tests/trace_cag/test_l1_state_cache.py b/ai-service/tests/trace_cag/test_l1_state_cache.py
index cd9a7ebc..41f08d7f 100644
--- a/ai-service/tests/trace_cag/test_l1_state_cache.py
+++ b/ai-service/tests/trace_cag/test_l1_state_cache.py
@@ -39,7 +39,7 @@ def _candidate(**overrides):
         "answer_target": "person",
         "relation_hints": {"founder", "maker"},
         "evidence_hash": "ev:iphone:apple",
-        "created_at": time.monotonic(),
+        "created_at": time.time(),
         "ttl": 3600,
     }
     base.update(overrides)
@@ -117,7 +117,7 @@ def test_l1_full_for_low_concept_overlap():
 
 
 def test_l1_full_for_stale_candidate():
-    candidate = _candidate(created_at=time.monotonic() - 7200, ttl=3600)
+    candidate = _candidate(created_at=time.time() - 7200, ttl=3600)
 
     decision = decide_l1_reuse(_request(), candidate)
 
diff --git a/ai-service/tests/trace_cag/test_native_language_hint.py b/ai-service/tests/trace_cag/test_native_language_hint.py
new file mode 100644
index 00000000..14fc196c
--- /dev/null
+++ b/ai-service/tests/trace_cag/test_native_language_hint.py
@@ -0,0 +1,30 @@
+"""Tests for the last-resort native-language fallback hint (nodes_v2._get_predefined_native_hint)."""
+
+import api.services.trace_cag.nodes_v2 as nodes
+
+_ERROR = {"type": "past_tense", "span": "go", "correction": "went", "explanation": "past tense"}
+
+
+def test_predefined_native_hint_vietnamese_no_errors():
+    assert "tốt" in nodes._get_predefined_native_hint([], "Vietnamese")
+
+
+def test_predefined_native_hint_vietnamese_known_error_type():
+    hint = nodes._get_predefined_native_hint([_ERROR], "Vietnamese")
+    assert "quá khứ" in hint
+
+
+def test_predefined_native_hint_japanese_does_not_fall_back_to_vietnamese():
+    hint = nodes._get_predefined_native_hint([_ERROR], "Japanese")
+    assert "quá khứ" not in hint
+    assert hint == nodes._PREDEFINED_NATIVE_EXPLANATIONS["Japanese"]["past_tense"]
+
+
+def test_predefined_native_hint_unsupported_language_falls_back_to_short_english():
+    hint = nodes._get_predefined_native_hint([_ERROR], "Thai")
+    assert hint == nodes._FALLBACK_NATIVE_DEFAULT
+
+
+def test_predefined_native_hint_unsupported_language_no_errors():
+    hint = nodes._get_predefined_native_hint([], "Thai")
+    assert hint == nodes._FALLBACK_NATIVE_NO_ERRORS
diff --git a/backend-service/.gitignore b/backend-service/.gitignore
index 4ae5ec72..c47b9c33 100644
--- a/backend-service/.gitignore
+++ b/backend-service/.gitignore
@@ -55,6 +55,9 @@ Thumbs.db
 .coverage
 htmlcov/
 *.cover
+coverage.xml
+pytest-output.txt
+proficiency-output.txt
 
 # Database
 *.db
@@ -69,3 +72,4 @@ data/
 # Logs
 *.log
 logs/
+import_*
diff --git a/backend-service/alembic/versions/add_game_powerup_shop_items.py b/backend-service/alembic/versions/add_game_powerup_shop_items.py
new file mode 100644
index 00000000..d73cd67f
--- /dev/null
+++ b/backend-service/alembic/versions/add_game_powerup_shop_items.py
@@ -0,0 +1,149 @@
+"""Add in-game power-up shop items (time freeze, skip token, shield, etc).
+
+Revision ID: add_game_powerup_items
+Revises: backfill_verified_users
+"""
+
+from typing import Sequence, Union
+import uuid
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import UUID as PG_UUID, JSON as PG_JSON
+
+
+revision: str = "add_game_powerup_items"
+down_revision: Union[str, None] = "backfill_verified_users"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+GAME_POWERUP_ITEMS: tuple[dict, ...] = (
+    {
+        "name": "Time Freeze",
+        "description": "Pause the countdown timer for 10 seconds in any timed game",
+        "item_type": "time_freeze",
+        "price_gems": 10,
+        "effects": {"seconds": 10},
+        "is_available": True,
+    },
+    {
+        "name": "Extra Time",
+        "description": "Add 20 seconds straight to the clock in any timed game",
+        "item_type": "extra_time",
+        "price_gems": 15,
+        "effects": {"seconds": 20},
+        "is_available": True,
+    },
+    {
+        "name": "Skip Token",
+        "description": "Skip the current word or question with no penalty",
+        "item_type": "skip_token",
+        "price_gems": 12,
+        "effects": {},
+        "is_available": True,
+    },
+    {
+        "name": "Magnifying Glass",
+        "description": "Free reveal: the next letter, or eliminate 2 wrong options",
+        "item_type": "reveal_hint",
+        "price_gems": 8,
+        "effects": {"mode": "letter"},
+        "is_available": True,
+    },
+    {
+        "name": "Quick Translate",
+        "description": "Reveal the Vietnamese translation of the current word",
+        "item_type": "translate_hint",
+        "price_gems": 8,
+        "effects": {"mode": "translation"},
+        "is_available": True,
+    },
+    {
+        "name": "Shield",
+        "description": "Negate the next wrong answer or life loss",
+        "item_type": "mistake_shield",
+        "price_gems": 18,
+        "effects": {},
+        "is_available": True,
+    },
+    {
+        "name": "Extra Heart",
+        "description": "Start Hangman with one extra life",
+        "item_type": "extra_heart",
+        "price_gems": 15,
+        "effects": {"lives": 1},
+        "is_available": True,
+    },
+    {
+        "name": "Lucky Clover",
+        "description": "30% chance to auto-correct your next wrong answer",
+        "item_type": "lucky_clover",
+        "price_gems": 20,
+        "effects": {"chance": 0.3},
+        "is_available": True,
+    },
+    {
+        "name": "Score Multiplier",
+        "description": "Double your in-game score for the rest of this session",
+        "item_type": "score_multiplier",
+        "price_gems": 22,
+        "effects": {"multiplier": 2},
+        "is_available": True,
+    },
+    {
+        "name": "Pair Swap",
+        "description": "Undo one wrong match in Matching Game for a free retry",
+        "item_type": "pair_swap",
+        "price_gems": 10,
+        "effects": {},
+        "is_available": True,
+    },
+)
+
+
+def upgrade() -> None:
+    connection = op.get_bind()
+
+    _insert = sa.text(
+        "INSERT INTO shop_items (id, name, description, item_type, price_gems, "
+        "effects, icon_url, is_available, created_at) VALUES "
+        "(:id, :name, :description, :item_type, :price_gems, :effects, :icon_url, :is_available, NOW())"
+    ).bindparams(
+        sa.bindparam("id", type_=PG_UUID()),
+        sa.bindparam("effects", type_=PG_JSON()),
+    )
+
+    _update = sa.text(
+        "UPDATE shop_items SET description=:description, item_type=:item_type, "
+        "price_gems=:price_gems, effects=:effects, icon_url=:icon_url, "
+        "is_available=:is_available WHERE name=:name"
+    ).bindparams(
+        sa.bindparam("effects", type_=PG_JSON()),
+    )
+
+    for item in GAME_POWERUP_ITEMS:
+        existing = connection.execute(
+            sa.text("SELECT name FROM shop_items WHERE name = :name"),
+            {"name": item["name"]},
+        ).first()
+        params = {
+            "name": item["name"],
+            "description": item["description"],
+            "item_type": item["item_type"],
+            "price_gems": item["price_gems"],
+            "effects": item.get("effects"),
+            "icon_url": item.get("icon_url"),
+            "is_available": item.get("is_available", True),
+        }
+        if existing:
+            connection.execute(_update, params)
+        else:
+            connection.execute(_insert, {"id": uuid.uuid4(), **params})
+
+
+def downgrade() -> None:
+    powerup_names = [item["name"] for item in GAME_POWERUP_ITEMS]
+    connection = op.get_bind()
+    shop_items = sa.table("shop_items", sa.column("name", sa.String()))
+    connection.execute(shop_items.delete().where(shop_items.c.name.in_(powerup_names)))
diff --git a/backend-service/alembic/versions/add_mistake_notebook_entries.py b/backend-service/alembic/versions/add_mistake_notebook_entries.py
new file mode 100644
index 00000000..7816a24f
--- /dev/null
+++ b/backend-service/alembic/versions/add_mistake_notebook_entries.py
@@ -0,0 +1,88 @@
+"""add synced mistake notebook entries
+
+Revision ID: add_mistake_notebook_entries
+Revises: add_game_powerup_items
+Create Date: 2026-07-03
+
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+from app.core.db_types import GUID, PortableJSON, TZDateTime
+
+
+# revision identifiers, used by Alembic.
+revision: str = "add_mistake_notebook_entries"
+down_revision: Union[str, None] = "add_game_powerup_items"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "mistake_notebook_entries",
+        sa.Column("id", GUID(), primary_key=True),
+        sa.Column(
+            "user_id",
+            GUID(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("client_id", sa.String(length=128), nullable=True),
+        sa.Column("source_type", sa.String(length=80), nullable=False),
+        sa.Column("source_id", sa.String(length=255), nullable=False),
+        sa.Column("source_title", sa.String(length=500), nullable=False, server_default=""),
+        sa.Column("question", sa.Text(), nullable=False),
+        sa.Column("question_hash", sa.String(length=64), nullable=False),
+        sa.Column("selected_answer", sa.Text(), nullable=False, server_default=""),
+        sa.Column("correct_answer", sa.Text(), nullable=False, server_default=""),
+        sa.Column("explanation", sa.Text(), nullable=False, server_default=""),
+        sa.Column("skill", sa.String(length=80), nullable=False, server_default="general"),
+        sa.Column("status", sa.String(length=20), nullable=False, server_default="open"),
+        sa.Column("review_count", sa.Integer(), nullable=False, server_default="0"),
+        sa.Column("attempt_count", sa.Integer(), nullable=False, server_default="1"),
+        sa.Column("extra_data", PortableJSON(), nullable=True),
+        sa.Column("created_at", TZDateTime(), nullable=False, server_default=sa.func.now()),
+        sa.Column("updated_at", TZDateTime(), nullable=False, server_default=sa.func.now()),
+        sa.Column("reviewed_at", TZDateTime(), nullable=True),
+        sa.Column("last_seen_at", TZDateTime(), nullable=False, server_default=sa.func.now()),
+        sa.UniqueConstraint(
+            "user_id",
+            "client_id",
+            name="uq_mistake_notebook_entries_user_client_id",
+        ),
+    )
+    op.create_index(
+        "ix_mistake_notebook_entries_user_id",
+        "mistake_notebook_entries",
+        ["user_id"],
+    )
+    op.create_index(
+        "ix_mistake_notebook_entries_user_status_created",
+        "mistake_notebook_entries",
+        ["user_id", "status", "created_at"],
+    )
+    op.create_index(
+        "ix_mistake_notebook_entries_user_source_question_hash",
+        "mistake_notebook_entries",
+        ["user_id", "source_type", "source_id", "question_hash"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_index(
+        "ix_mistake_notebook_entries_user_source_question_hash",
+        table_name="mistake_notebook_entries",
+    )
+    op.drop_index(
+        "ix_mistake_notebook_entries_user_status_created",
+        table_name="mistake_notebook_entries",
+    )
+    op.drop_index(
+        "ix_mistake_notebook_entries_user_id",
+        table_name="mistake_notebook_entries",
+    )
+    op.drop_table("mistake_notebook_entries")
diff --git a/backend-service/alembic/versions/backfill_is_verified_legacy_users.py b/backend-service/alembic/versions/backfill_is_verified_legacy_users.py
new file mode 100644
index 00000000..37a3fae3
--- /dev/null
+++ b/backend-service/alembic/versions/backfill_is_verified_legacy_users.py
@@ -0,0 +1,46 @@
+"""Backfill is_verified for users created before email-verification enforcement
+
+Revision ID: backfill_verified_users
+Revises: 0d7ae4e272b7
+Create Date: 2026-06-23
+
+login/refresh now reject accounts with is_verified=False (see
+app/routes/auth.py, commit 41613c45). Accounts registered before that
+enforcement existed were never required to verify their email, so without
+this backfill every pre-existing unverified local account would be locked
+out on its next login attempt.
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision: str = "backfill_verified_users"
+down_revision: Union[str, None] = "0d7ae4e272b7"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+# Cutoff = author timestamp of commit 41613c45 ("fix(auth): block
+# login/refresh for unverified email accounts"). Users registered at or
+# after this point were always subject to the enforcement and must verify
+# normally.
+ENFORCEMENT_CUTOFF = "2026-06-23T11:48:46+07:00"
+
+
+def upgrade() -> None:
+    op.execute(
+        f"""
+        UPDATE users
+        SET is_verified = TRUE
+        WHERE is_verified = FALSE
+          AND created_at < TIMESTAMP WITH TIME ZONE '{ENFORCEMENT_CUTOFF}'
+        """
+    )
+
+
+def downgrade() -> None:
+    # Backfill is one-directional by design — there is no reliable way to
+    # tell which legacy users were "really" unverified vs. grandfathered in.
+    pass
diff --git a/backend-service/app/check_missing.py b/backend-service/app/check_missing.py
deleted file mode 100644
index 92d5d469..00000000
--- a/backend-service/app/check_missing.py
+++ /dev/null
@@ -1,54 +0,0 @@
-import json
-import asyncio
-import sys
-from sqlalchemy import select, func
-from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
-from sqlalchemy.orm import sessionmaker
-
-sys.path.append("/app")
-from app.models.vocabulary import VocabularyItem, PartOfSpeech
-from app.core.config import settings
-
-INPUT_FILE = "/app/data/vocabulary_import.json"
-
-def guess_pos(word, defn):
-    # Remove Vietnamese "v.v." / "v. v." to prevent false verb matching on " v."
-    clean_defn = defn.replace("v.v.", "").replace("v. v.", "")
-    if " v." in clean_defn or " verb" in clean_defn or word.startswith("to "):
-        return PartOfSpeech.VERB
-    if " adj." in clean_defn or " adj " in clean_defn:
-        return PartOfSpeech.ADJECTIVE
-    if " adv." in clean_defn or " adv " in clean_defn:
-        return PartOfSpeech.ADVERB
-    if " phrase" in clean_defn or " idiom" in clean_defn or " " in word:
-        return PartOfSpeech.PHRASE
-    return PartOfSpeech.NOUN
-
-async def main():
-    with open(INPUT_FILE, "r", encoding="utf-8") as f:
-        data = json.load(f)
-
-    engine = create_async_engine(settings.async_database_url, echo=False)
-    AsyncSessionLocal = sessionmaker(
-        engine, class_=AsyncSession, expire_on_commit=False
-    )
-    
-    async with AsyncSessionLocal() as session:
-        # Get all existing word + part_of_speech pairs
-        result = await session.execute(select(VocabularyItem.word, VocabularyItem.part_of_speech))
-        existing = {(r[0], r[1]) for r in result.all()}
-        
-        missing_count = 0
-        for item in data:
-            word = item['word'][:255]
-            defn = item.get('definition', '')
-            pos = guess_pos(word, defn)
-            if (word, pos) not in existing:
-                missing_count += 1
-                
-        print(f"TOTAL_IN_JSON: {len(data)}")
-        print(f"EXISTING_IN_DB: {len(existing)}")
-        print(f"MISSING_FROM_DB: {missing_count}")
-
-if __name__ == "__main__":
-    asyncio.run(main())
diff --git a/backend-service/app/core/config.py b/backend-service/app/core/config.py
index dcda135f..a192c84d 100644
--- a/backend-service/app/core/config.py
+++ b/backend-service/app/core/config.py
@@ -4,12 +4,12 @@
 Using Pydantic settings for type-safe configuration
 """
 
-from typing import List
-from pathlib import Path
 import os
-from pydantic_settings import BaseSettings, SettingsConfigDict
-from pydantic import field_validator, model_validator
+from pathlib import Path
+
 from dotenv import load_dotenv
+from pydantic import field_validator, model_validator
+from pydantic_settings import BaseSettings, SettingsConfigDict
 
 # Get project root directory and load environment files explicitly.
 # Always load .env first, then override with .env.production in production mode.
@@ -22,14 +22,26 @@
 
 class Settings(BaseSettings):
     """Application settings."""
-    
+
     # Application
     APP_NAME: str = "LexiLingo Backend Service"
     APP_ENV: str = "development"
     API_V1_PREFIX: str = "/api/v1"
     DEBUG: bool = False
     PORT: int = 8000
-    
+
+    @field_validator("DEBUG", mode="before")
+    @classmethod
+    def parse_debug_flag(cls, value):
+        """Accept Flutter-style build mode strings used by local env files."""
+        if isinstance(value, str):
+            normalized = value.strip().lower()
+            if normalized == "release":
+                return False
+            if normalized == "debug":
+                return True
+        return value
+
     # Database
     DATABASE_URL: str
     DB_ECHO: bool = False
@@ -52,7 +64,7 @@ def async_database_url(self) -> str:
         elif url.startswith("postgresql://") and "+asyncpg" not in url:
             url = url.replace("postgresql://", "postgresql+asyncpg://", 1)
         return url
-    
+
     # Request limits
     MAX_REQUEST_BODY_BYTES: int = 10 * 1024 * 1024  # 10 MB
 
@@ -65,7 +77,7 @@ def effective_pool_size(self) -> int:
     def effective_max_overflow(self) -> int:
         """Return larger overflow in production."""
         return 50 if self.is_production else self.DB_MAX_OVERFLOW
-    
+
     # Security
     SECRET_KEY: str
     ALGORITHM: str = "HS256"
@@ -73,7 +85,7 @@ def effective_max_overflow(self) -> int:
     JWT_AUDIENCE: str = "lexilingo-services"
     ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
     REFRESH_TOKEN_EXPIRE_DAYS: int = 7
-    
+
     # CORS
     # ENABLE_APP_CORS: explicit override (takes priority over GATEWAY_HANDLES_CORS).
     # GATEWAY_HANDLES_CORS: set true only when an Nginx/Kong gateway sits in front
@@ -82,11 +94,11 @@ def effective_max_overflow(self) -> int:
     #   Default false (safe for direct Render/PaaS deployments without a gateway).
     ENABLE_APP_CORS: bool | None = None
     GATEWAY_HANDLES_CORS: bool = False
-    ALLOWED_ORIGINS: str = "https://lexilingo.me,https://www.lexilingo.me,https://admin.lexilingo.me"
-    CORS_ALLOW_ORIGIN_REGEX: str = (
-        r"https?://([a-zA-Z0-9-]+\.)*lexilingo\.me(:\d+)?"
+    ALLOWED_ORIGINS: str = (
+        "https://lexilingo.me,https://www.lexilingo.me,https://admin.lexilingo.me"
     )
-    ALLOWED_HOSTS: List[str] = [
+    CORS_ALLOW_ORIGIN_REGEX: str = r"https?://([a-zA-Z0-9-]+\.)*lexilingo\.me(:\d+)?"
+    ALLOWED_HOSTS: list[str] = [
         "api.lexilingo.me",
         "*.lexilingo.me",
         "lexilingo-backend.onrender.com",
@@ -99,15 +111,11 @@ def parse_allowed_hosts(cls, value):
         if isinstance(value, str):
             return [host.strip() for host in value.split(",") if host.strip()]
         return value
-    
+
     @property
-    def cors_origins(self) -> List[str]:
+    def cors_origins(self) -> list[str]:
         """Parse ALLOWED_ORIGINS string to list"""
-        return [
-            origin.strip()
-            for origin in self.ALLOWED_ORIGINS.split(",")
-            if origin.strip()
-        ]
+        return [origin.strip() for origin in self.ALLOWED_ORIGINS.split(",") if origin.strip()]
 
     @model_validator(mode="after")
     def validate_production_security(self):
@@ -124,14 +132,18 @@ def validate_production_security(self):
         if self.enable_app_cors:
             origins = self.cors_origins
             local_origins = [
-                origin for origin in origins
-                if "localhost" in origin or "127.0.0.1" in origin
+                origin for origin in origins if "localhost" in origin or "127.0.0.1" in origin
             ]
             if "*" in origins:
-                raise ValueError("Wildcard CORS origins are not allowed with credentials in production")
+                raise ValueError(
+                    "Wildcard CORS origins are not allowed with credentials in production"
+                )
             if local_origins:
                 raise ValueError("Localhost CORS origins are not allowed when APP_ENV=production")
-            if "devtunnels.ms" in self.CORS_ALLOW_ORIGIN_REGEX or "github.dev" in self.CORS_ALLOW_ORIGIN_REGEX:
+            if (
+                "devtunnels.ms" in self.CORS_ALLOW_ORIGIN_REGEX
+                or "github.dev" in self.CORS_ALLOW_ORIGIN_REGEX
+            ):
                 raise ValueError("Broad development tunnel CORS regex is not allowed in production")
 
         if self.CONTENT_AGENT_ENABLED and not self.CONTENT_AGENT_SERVICE_TOKEN.strip():
@@ -140,7 +152,7 @@ def validate_production_security(self):
             )
 
         return self
-    
+
     # Logging
     LOG_LEVEL: str = "INFO"
 
@@ -160,7 +172,7 @@ def validate_production_security(self):
     PASSWORD_RESET_URL_BASE_PRODUCTION: str | None = None
     EMAIL_VERIFICATION_URL_BASE: str = "https://lexilingo.me/verify-email"
     EMAIL_VERIFICATION_URL_BASE_PRODUCTION: str | None = None
-    
+
     # AI Service (optional)
     AI_SERVICE_URL: str = "https://api.lexilingo.me/api/v1"
     AI_AUDIT_INGEST_SECRET: str = ""
@@ -189,21 +201,17 @@ def validate_production_security(self):
     SUPER_ADMIN_EMAIL_WHITELIST: str = ""
 
     @staticmethod
-    def _parse_email_list(raw_value: str) -> List[str]:
+    def _parse_email_list(raw_value: str) -> list[str]:
         """Normalize a comma-separated email allowlist."""
-        return [
-            email.strip().lower()
-            for email in raw_value.split(",")
-            if email.strip()
-        ]
+        return [email.strip().lower() for email in raw_value.split(",") if email.strip()]
 
     @property
-    def admin_email_whitelist(self) -> List[str]:
+    def admin_email_whitelist(self) -> list[str]:
         """Emails allowed to access the admin application."""
         return self._parse_email_list(self.ADMIN_EMAIL_WHITELIST)
 
     @property
-    def super_admin_email_whitelist(self) -> List[str]:
+    def super_admin_email_whitelist(self) -> list[str]:
         """Emails that should receive super_admin on first Google login."""
         return self._parse_email_list(self.SUPER_ADMIN_EMAIL_WHITELIST)
 
@@ -262,24 +270,22 @@ def effective_celery_result_backend(self) -> str:
         return self.CELERY_RESULT_BACKEND or self.REDIS_URL
 
     # ── External API Keys (Phase 0+ Content Features) ──
-    YOUTUBE_API_KEY: str | None = None           # YouTube Data API v3
-    NEWSAPI_KEY: str | None = None               # NewsAPI.org
-    NEWSDATA_KEY: str | None = None              # NewsData.io (fallback)
-    PODCASTINDEX_KEY: str | None = None          # PodcastIndex.org
-    PODCASTINDEX_SECRET: str | None = None       # PodcastIndex.org secret
+    YOUTUBE_API_KEY: str | None = None  # YouTube Data API v3
+    NEWSAPI_KEY: str | None = None  # NewsAPI.org
+    NEWSDATA_KEY: str | None = None  # NewsData.io (fallback)
+    PODCASTINDEX_KEY: str | None = None  # PodcastIndex.org
+    PODCASTINDEX_SECRET: str | None = None  # PodcastIndex.org secret
     DICTIONARY_API_BASE_URL: str = "https://api.dictionaryapi.dev/api/v2/entries/en"
-    
+
     model_config = SettingsConfigDict(
-        env_file=str(PROJECT_ROOT / ".env"),
-        case_sensitive=True,
-        extra="ignore"
+        env_file=str(PROJECT_ROOT / ".env"), case_sensitive=True, extra="ignore"
     )
-    
+
     @property
     def is_development(self) -> bool:
         """Check if running in development mode."""
         return self.APP_ENV == "development"
-    
+
     @property
     def is_production(self) -> bool:
         """Check if running in production mode."""
diff --git a/backend-service/app/core/dependencies.py b/backend-service/app/core/dependencies.py
index 9d43108f..6826a348 100644
--- a/backend-service/app/core/dependencies.py
+++ b/backend-service/app/core/dependencies.py
@@ -15,6 +15,7 @@
 
 from app.core.database import get_db
 from app.core.security import decode_token
+from app.core.token_blacklist import TokenBlacklist
 from app.core.firebase_auth import verify_firebase_token, get_or_create_user_from_claims
 from app.models.user import User
 
@@ -36,6 +37,11 @@ async def get_me(current_user: User = Depends(get_current_user)):
             return current_user
     """
     token = credentials.credentials
+    if await TokenBlacklist.is_blacklisted(token):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid authentication token"
+        )
     
     # 1) Try local JWT (backward compatibility)
     payload = decode_token(token)
@@ -96,6 +102,8 @@ async def get_courses(current_user: Optional[User] = Depends(get_current_user_op
         return None
     
     token = credentials.credentials
+    if await TokenBlacklist.is_blacklisted(token):
+        return None
     
     # 1) Try local JWT
     payload = decode_token(token)
diff --git a/backend-service/app/core/exceptions.py b/backend-service/app/core/exceptions.py
index 96af838a..bc23915e 100644
--- a/backend-service/app/core/exceptions.py
+++ b/backend-service/app/core/exceptions.py
@@ -63,7 +63,7 @@ async def validation_exception_handler(request: Request, exc: RequestValidationE
     )
     
     return JSONResponse(
-        status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+        status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
         content=error_response.model_dump(mode="json")
     )
 
diff --git a/backend-service/app/core/sample_data_catalog.py b/backend-service/app/core/sample_data_catalog.py
new file mode 100644
index 00000000..9223cd55
--- /dev/null
+++ b/backend-service/app/core/sample_data_catalog.py
@@ -0,0 +1,468 @@
+"""Canonical sample data used by the dev-only /admin/seed endpoint."""
+
+from typing import Any
+
+SAMPLE_ACHIEVEMENTS: list[dict[str, Any]] = [
+    {"name": "First Steps", "description": "Complete your first lesson",
+     "condition_type": "lessons_completed", "condition_value": 1,
+     "category": "lessons", "rarity": "common", "xp_reward": 10, "gems_reward": 5},
+    {"name": "Week Warrior", "description": "Maintain a 7-day streak",
+     "condition_type": "streak_days", "condition_value": 7,
+     "category": "streak", "rarity": "rare", "xp_reward": 50, "gems_reward": 20},
+    {"name": "Word Collector", "description": "Add 100 words to vocabulary",
+     "condition_type": "vocab_count", "condition_value": 100,
+     "category": "vocabulary", "rarity": "epic", "xp_reward": 100, "gems_reward": 50},
+    {"name": "Social Butterfly", "description": "Follow 10 friends",
+     "condition_type": "following_count", "condition_value": 10,
+     "category": "social", "rarity": "rare", "xp_reward": 30, "gems_reward": 15},
+]
+
+SAMPLE_COURSE_CATEGORIES: list[dict[str, Any]] = [
+    {
+        "name": "Grammar",
+        "slug": "grammar",
+        "description": "Master English grammar rules and structures",
+        "icon": "📚",
+        "color": "#4CAF50",
+        "order_index": 1,
+    },
+    {
+        "name": "Vocabulary",
+        "slug": "vocabulary",
+        "description": "Build practical English vocabulary for daily use",
+        "icon": "🧠",
+        "color": "#2196F3",
+        "order_index": 2,
+    },
+]
+
+SAMPLE_COURSES: list[dict[str, Any]] = [
+    {
+        "title": "English Grammar Foundations",
+        "description": "Start with core grammar patterns for everyday communication.",
+        "language": "en",
+        "level": "A1",
+        "category_slug": "grammar",
+        "tags": ["grammar", "beginner", "fundamentals"],
+        "total_xp": 120,
+        "estimated_duration": 90,
+        "thumbnail_url": "https://images.unsplash.com/photo-1456513080510-7bf3a84b82f8",
+        "units": [
+            {
+                "title": "Present Simple Basics",
+                "description": "Build confidence with daily routine sentences.",
+                "order_index": 1,
+                "background_color": "#1E3A8A",
+                "lessons": [
+                    {
+                        "title": "I/You/We/They + Verb",
+                        "description": "Form positive present simple sentences.",
+                        "order_index": 1,
+                        "estimated_minutes": 12,
+                        "xp_reward": 20,
+                        "total_exercises": 10,
+                        "exercises": [
+                            {
+                                "id": "ex_g1_1",
+                                "type": "multiple_choice",
+                                "ui_type": "multiple_choice",
+                                "question": "Choose the correct form: 'I ___ coffee every morning.'",
+                                "options": [{"id": "0", "text": "drink", "is_correct": True}, {"id": "1", "text": "drinks", "is_correct": False}, {"id": "2", "text": "drinking", "is_correct": False}, {"id": "3", "text": "drunk", "is_correct": False}],
+                                "correct_answer": "drink",
+                                "explanation": "With I/You/We/They, use the base verb form."
+                            },
+                            {
+                                "id": "ex_g1_2",
+                                "type": "true_false",
+                                "ui_type": "true_or_false",
+                                "question": "True or False: 'They plays football' is grammatically correct.",
+                                "options": [{"id": "0", "text": "True", "is_correct": False}, {"id": "1", "text": "False", "is_correct": True}],
+                                "correct_answer": "False",
+                                "explanation": "'They' is plural and takes the base verb 'play', not 'plays'."
+                            },
+                            {
+                                "id": "ex_g1_3",
+                                "type": "fill_blank",
+                                "ui_type": "fill_in_the_blank",
+                                "question": "Complete the sentence: 'We {blank} in a big city.'",
+                                "correct_answer": "live",
+                                "explanation": "'We' takes the base verb 'live'."
+                            },
+                            {
+                                "id": "ex_g1_4",
+                                "type": "reorder",
+                                "ui_type": "arrange_the_sentence",
+                                "question": "Arrange: 'day / every / study / they'",
+                                "options": [{"id": "0", "text": "they"}, {"id": "1", "text": "study"}, {"id": "2", "text": "every"}, {"id": "3", "text": "day"}],
+                                "correct_answer": "they study every day",
+                                "explanation": "Subject + Verb + Time expression is the standard structure."
+                            },
+                            {
+                                "id": "ex_g1_5",
+                                "type": "translate",
+                                "ui_type": "translation_choice",
+                                "question": "Choose the translation for: 'Chúng tôi muốn học.'",
+                                "options": [{"id": "0", "text": "We want to learn.", "is_correct": True}, {"id": "1", "text": "We wants to learn.", "is_correct": False}, {"id": "2", "text": "We learning.", "is_correct": False}],
+                                "correct_answer": "We want to learn.",
+                                "explanation": "'Chúng tôi' translates to 'We', which takes the base verb 'want'."
+                            },
+                            {
+                                "id": "ex_g1_6",
+                                "type": "fill_blank",
+                                "ui_type": "dialogue_completion",
+                                "question": "A: Do you speak English? B: Yes, I {blank}.",
+                                "correct_answer": "do",
+                                "explanation": "Short answer to 'Do you...' is 'I do'."
+                            },
+                            {
+                                "id": "ex_g1_7",
+                                "type": "multiple_choice",
+                                "ui_type": "collocation_choice",
+                                "question": "Complete the phrase: 'They ___ homework together.'",
+                                "options": [{"id": "0", "text": "do", "is_correct": True}, {"id": "1", "text": "make", "is_correct": False}],
+                                "correct_answer": "do",
+                                "explanation": "The collocation is 'do homework'."
+                            },
+                            {
+                                "id": "ex_g1_8",
+                                "type": "fill_blank",
+                                "ui_type": "dictation",
+                                "question": "Listen and write what you hear: '{blank}'",
+                                "correct_answer": "We go home",
+                                "explanation": "Type the exact words heard in the audio."
+                            },
+                            {
+                                "id": "ex_g1_9",
+                                "type": "translate",
+                                "ui_type": "speaking_repeat",
+                                "question": "Repeat: 'I listen to music.'",
+                                "correct_answer": "I listen to music",
+                                "explanation": "Record yourself repeating this sentence."
+                            },
+                            {
+                                "id": "ex_g1_10",
+                                "type": "multiple_choice",
+                                "ui_type": "vocabulary_flashcard",
+                                "question": "Learn the card: 'Routine'",
+                                "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
+                                "correct_answer": "Got it!",
+                                "explanation": "Routine is a sequence of actions regularly followed."
+                            }
+                        ]
+                    },
+                    {
+                        "title": "He/She/It + Verb-s",
+                        "description": "Use third-person singular correctly.",
+                        "order_index": 2,
+                        "estimated_minutes": 12,
+                        "xp_reward": 20,
+                        "total_exercises": 10,
+                        "exercises": [
+                            {
+                                "id": "ex_g2_1",
+                                "type": "multiple_choice",
+                                "ui_type": "multiple_choice",
+                                "question": "Choose correct: 'He ___ to school by bus.'",
+                                "options": [{"id": "0", "text": "go", "is_correct": False}, {"id": "1", "text": "goes", "is_correct": True}, {"id": "2", "text": "going", "is_correct": False}],
+                                "correct_answer": "goes",
+                                "explanation": "He/she/it takes verb+s/es."
+                            },
+                            {
+                                "id": "ex_g2_2",
+                                "type": "true_false",
+                                "ui_type": "true_or_false",
+                                "question": "True or False: 'It rain a lot' is correct.",
+                                "options": [{"id": "0", "text": "True", "is_correct": False}, {"id": "1", "text": "False", "is_correct": True}],
+                                "correct_answer": "False",
+                                "explanation": "It should be 'It rains a lot'."
+                            },
+                            {
+                                "id": "ex_g2_3",
+                                "type": "fill_blank",
+                                "ui_type": "fill_in_the_blank",
+                                "question": "Complete: 'She {blank} the piano well.'",
+                                "correct_answer": "plays",
+                                "explanation": "She requires plays."
+                            },
+                            {
+                                "id": "ex_g2_4",
+                                "type": "fill_blank",
+                                "ui_type": "grammar_correction",
+                                "question": "Correct the error: 'He play tennis.' -> '{blank}'",
+                                "correct_answer": "He plays tennis",
+                                "explanation": "Add 's' to play."
+                            },
+                            {
+                                "id": "ex_g2_5",
+                                "type": "multiple_choice",
+                                "ui_type": "image_based_choice",
+                                "question": "Choose the image that represents: 'She runs.'",
+                                "options": [{"id": "0", "text": "Running", "is_correct": True}, {"id": "1", "text": "Sleeping", "is_correct": False}],
+                                "correct_answer": "Running",
+                                "explanation": "Select the correct action card."
+                            },
+                            {
+                                "id": "ex_g2_6",
+                                "type": "multiple_choice",
+                                "ui_type": "listen_and_choose",
+                                "question": "Listen and select what he does.",
+                                "options": [{"id": "0", "text": "He eats breakfast", "is_correct": True}, {"id": "1", "text": "He plays games", "is_correct": False}],
+                                "correct_answer": "He eats breakfast",
+                                "explanation": "Audio matches breakfast."
+                            },
+                            {
+                                "id": "ex_g2_7",
+                                "type": "translate",
+                                "ui_type": "pronunciation_practice",
+                                "question": "Practice speaking: 'He plays tennis.'",
+                                "correct_answer": "He plays tennis",
+                                "explanation": "Evaluate pronunciation of He plays tennis."
+                            },
+                            {
+                                "id": "ex_g2_8",
+                                "type": "multiple_choice",
+                                "ui_type": "reading_comprehension",
+                                "question": "Read and answer: 'Tom is a chef. He works in a restaurant.' Where does Tom work?",
+                                "options": [{"id": "0", "text": "restaurant", "is_correct": True}, {"id": "1", "text": "office", "is_correct": False}],
+                                "correct_answer": "restaurant",
+                                "explanation": "The text states he works in a restaurant."
+                            },
+                            {
+                                "id": "ex_g2_9",
+                                "type": "fill_blank",
+                                "ui_type": "short_writing_answer",
+                                "question": "Write in English: 'Cô ấy nói tiếng Anh.'",
+                                "correct_answer": "She speaks English",
+                                "explanation": "Translate exactly."
+                            },
+                            {
+                                "id": "ex_g2_10",
+                                "type": "matching",
+                                "ui_type": "categorization",
+                                "question": "Categorize the pronouns: Singular vs Plural",
+                                "options": [{"id": "he", "text": "Singular"}, {"id": "they", "text": "Plural"}],
+                                "correct_answer": "he:Singular, they:Plural",
+                                "explanation": "He is singular, they is plural."
+                            }
+                        ]
+                    },
+                ],
+            },
+        ],
+    },
+    {
+        "title": "Daily Vocabulary Starter",
+        "description": "Learn essential words and phrases for daily life.",
+        "language": "en",
+        "level": "A1",
+        "category_slug": "vocabulary",
+        "tags": ["vocabulary", "daily-life", "beginner"],
+        "total_xp": 120,
+        "estimated_duration": 80,
+        "thumbnail_url": "https://images.unsplash.com/photo-1434030216411-0b793f4b4173",
+        "units": [
+            {
+                "title": "Home and Family",
+                "description": "Words you use every day at home.",
+                "order_index": 1,
+                "background_color": "#0F766E",
+                "lessons": [
+                    {
+                        "title": "Family Members",
+                        "description": "Describe people in your family.",
+                        "order_index": 1,
+                        "estimated_minutes": 10,
+                        "xp_reward": 20,
+                        "total_exercises": 10,
+                        "exercises": [
+                            {
+                                "id": "ex_v1_1",
+                                "type": "multiple_choice",
+                                "ui_type": "multiple_choice",
+                                "question": "Your father's sister is your ___.",
+                                "options": [{"id": "0", "text": "aunt", "is_correct": True}, {"id": "1", "text": "uncle", "is_correct": False}],
+                                "correct_answer": "aunt",
+                                "explanation": "Father's sister is aunt."
+                            },
+                            {
+                                "id": "ex_v1_2",
+                                "type": "matching",
+                                "ui_type": "match_word_to_meaning",
+                                "question": "Match the family words with meanings.",
+                                "options": [{"id": "father", "text": "Male parent"}, {"id": "mother", "text": "Female parent"}],
+                                "correct_answer": "father:Male parent, mother:Female parent",
+                                "explanation": "Father is male parent, mother is female."
+                            },
+                            {
+                                "id": "ex_v1_3",
+                                "type": "fill_blank",
+                                "ui_type": "fill_in_the_blank",
+                                "question": "Complete: 'My mother's husband is my {blank}.'",
+                                "correct_answer": "father",
+                                "explanation": "Mother's husband is father."
+                            },
+                            {
+                                "id": "ex_v1_4",
+                                "type": "matching",
+                                "ui_type": "cognitive_fluidity",
+                                "question": "Match: mother, sister",
+                                "options": [{"id": "mother", "text": "female parent"}, {"id": "sister", "text": "female sibling"}],
+                                "correct_answer": "mother:female parent, sister:female sibling",
+                                "explanation": "Fast match."
+                            },
+                            {
+                                "id": "ex_v1_5",
+                                "type": "multiple_choice",
+                                "ui_type": "vocabulary_flashcard",
+                                "question": "Learn: 'Sibling' (anh chị em ruột)",
+                                "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
+                                "correct_answer": "Got it!",
+                                "explanation": "A sibling is a brother or sister."
+                            },
+                            {
+                                "id": "ex_v1_6",
+                                "type": "true_false",
+                                "ui_type": "true_or_false",
+                                "question": "True or False: 'Cousin' is the child of your aunt or uncle.",
+                                "options": [{"id": "0", "text": "True", "is_correct": True}, {"id": "1", "text": "False", "is_correct": False}],
+                                "correct_answer": "True",
+                                "explanation": "Cousin is child of aunt/uncle."
+                            },
+                            {
+                                "id": "ex_v1_7",
+                                "type": "reorder",
+                                "ui_type": "arrange_the_sentence",
+                                "question": "Arrange: 'my / this / is / brother'",
+                                "options": [{"id": "0", "text": "this"}, {"id": "1", "text": "is"}, {"id": "2", "text": "my"}, {"id": "3", "text": "brother"}],
+                                "correct_answer": "this is my brother",
+                                "explanation": "Sentence structure."
+                            },
+                            {
+                                "id": "ex_v1_8",
+                                "type": "translate",
+                                "ui_type": "translation_choice",
+                                "question": "Translation of: 'Anh trai'",
+                                "options": [{"id": "0", "text": "brother", "is_correct": True}, {"id": "1", "text": "sister", "is_correct": False}],
+                                "correct_answer": "brother",
+                                "explanation": "Anh trai is brother."
+                            },
+                            {
+                                "id": "ex_v1_9",
+                                "type": "translate",
+                                "ui_type": "speaking_repeat",
+                                "question": "Repeat: 'My grandmother is nice.'",
+                                "correct_answer": "My grandmother is nice",
+                                "explanation": "Practice speaking."
+                            },
+                            {
+                                "id": "ex_v1_10",
+                                "type": "fill_blank",
+                                "ui_type": "dictation",
+                                "question": "Dictation: Listen and write '{blank}'",
+                                "correct_answer": "He is my uncle",
+                                "explanation": "Type what you hear."
+                            }
+                        ]
+                    },
+                    {
+                        "title": "Rooms and Objects",
+                        "description": "Talk about places and things at home.",
+                        "order_index": 2,
+                        "estimated_minutes": 10,
+                        "xp_reward": 20,
+                        "total_exercises": 10,
+                        "exercises": [
+                            {
+                                "id": "ex_v2_1",
+                                "type": "multiple_choice",
+                                "ui_type": "multiple_choice",
+                                "question": "You cook meals in the ___.",
+                                "options": [{"id": "0", "text": "kitchen", "is_correct": True}, {"id": "1", "text": "bedroom", "is_correct": False}],
+                                "correct_answer": "kitchen",
+                                "explanation": "Kitchen is for cooking."
+                            },
+                            {
+                                "id": "ex_v2_2",
+                                "type": "matching",
+                                "ui_type": "match_word_to_meaning",
+                                "question": "Match rooms with objects.",
+                                "options": [{"id": "bedroom", "text": "bed"}, {"id": "kitchen", "text": "fridge"}],
+                                "correct_answer": "bedroom:bed, kitchen:fridge",
+                                "explanation": "Bed in bedroom, fridge in kitchen."
+                            },
+                            {
+                                "id": "ex_v2_3",
+                                "type": "fill_blank",
+                                "ui_type": "fill_in_the_blank",
+                                "question": "Complete: 'I sleep in my {blank}.'",
+                                "correct_answer": "bedroom",
+                                "explanation": "Bedroom is for sleeping."
+                            },
+                            {
+                                "id": "ex_v2_4",
+                                "type": "true_false",
+                                "ui_type": "true_or_false",
+                                "question": "True or False: A sofa is typically placed in the living room.",
+                                "options": [{"id": "0", "text": "True", "is_correct": True}, {"id": "1", "text": "False", "is_correct": False}],
+                                "correct_answer": "True",
+                                "explanation": "Sofa in living room."
+                            },
+                            {
+                                "id": "ex_v2_5",
+                                "type": "reorder",
+                                "ui_type": "arrange_the_sentence",
+                                "question": "Arrange: 'in / the / bed / is / bedroom / the'",
+                                "options": [{"id": "0", "text": "the"}, {"id": "1", "text": "bed"}, {"id": "2", "text": "is"}, {"id": "3", "text": "in"}, {"id": "4", "text": "the"}, {"id": "5", "text": "bedroom"}],
+                                "correct_answer": "the bed is in the bedroom",
+                                "explanation": "Correct sentence structure."
+                            },
+                            {
+                                "id": "ex_v2_6",
+                                "type": "translate",
+                                "ui_type": "translation_choice",
+                                "question": "Translation of: 'Phòng tắm'",
+                                "options": [{"id": "0", "text": "bathroom", "is_correct": True}, {"id": "1", "text": "garden", "is_correct": False}],
+                                "correct_answer": "bathroom",
+                                "explanation": "Phòng tắm is bathroom."
+                            },
+                            {
+                                "id": "ex_v2_7",
+                                "type": "translate",
+                                "ui_type": "speaking_repeat",
+                                "question": "Repeat: 'The desk is clean.'",
+                                "correct_answer": "The desk is clean",
+                                "explanation": "Evaluate pronunciation."
+                            },
+                            {
+                                "id": "ex_v2_8",
+                                "type": "fill_blank",
+                                "ui_type": "dictation",
+                                "question": "Dictation: Listen and write '{blank}'",
+                                "correct_answer": "Open the window",
+                                "explanation": "Write what you hear."
+                            },
+                            {
+                                "id": "ex_v2_9",
+                                "type": "multiple_choice",
+                                "ui_type": "image_based_choice",
+                                "question": "Select the image that shows a table.",
+                                "options": [{"id": "0", "text": "Table", "is_correct": True}, {"id": "1", "text": "Chair", "is_correct": False}],
+                                "correct_answer": "Table",
+                                "explanation": "Card with table."
+                            },
+                            {
+                                "id": "ex_v2_10",
+                                "type": "multiple_choice",
+                                "ui_type": "vocabulary_flashcard",
+                                "question": "Learn: 'Furnishings'",
+                                "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
+                                "correct_answer": "Got it!",
+                                "explanation": "Furniture and appliances in a room."
+                            }
+                        ]
+                    },
+                ],
+            },
+        ],
+    },
+]
diff --git a/backend-service/app/core/shop_catalog.py b/backend-service/app/core/shop_catalog.py
index bf4f4240..8a36c106 100644
--- a/backend-service/app/core/shop_catalog.py
+++ b/backend-service/app/core/shop_catalog.py
@@ -89,6 +89,99 @@ def _avatar_item(seed: str, price: int) -> dict[str, Any]:
         "effects": {"quantity": 3},
         "is_available": True,
     },
+    {
+        "name": "Time Freeze",
+        "description": "Pause the countdown timer for 10 seconds in any timed game",
+        "item_type": "time_freeze",
+        "price_gems": 10,
+        "effects": {"seconds": 10},
+        "is_available": True,
+    },
+    {
+        "name": "Extra Time",
+        "description": "Add 20 seconds straight to the clock in any timed game",
+        "item_type": "extra_time",
+        "price_gems": 15,
+        "effects": {"seconds": 20},
+        "is_available": True,
+    },
+    {
+        "name": "Skip Token",
+        "description": "Skip the current word or question with no penalty",
+        "item_type": "skip_token",
+        "price_gems": 12,
+        "effects": {},
+        "is_available": True,
+    },
+    {
+        "name": "Magnifying Glass",
+        "description": "Free reveal: the next letter, or eliminate 2 wrong options",
+        "item_type": "reveal_hint",
+        "price_gems": 8,
+        "effects": {"mode": "letter"},
+        "is_available": True,
+    },
+    {
+        "name": "Quick Translate",
+        "description": "Reveal the Vietnamese translation of the current word",
+        "item_type": "translate_hint",
+        "price_gems": 8,
+        "effects": {"mode": "translation"},
+        "is_available": True,
+    },
+    {
+        "name": "Shield",
+        "description": "Negate the next wrong answer or life loss",
+        "item_type": "mistake_shield",
+        "price_gems": 18,
+        "effects": {},
+        "is_available": True,
+    },
+    {
+        "name": "Extra Heart",
+        "description": "Start Hangman with one extra life",
+        "item_type": "extra_heart",
+        "price_gems": 15,
+        "effects": {"lives": 1},
+        "is_available": True,
+    },
+    {
+        "name": "Lucky Clover",
+        "description": "30% chance to auto-correct your next wrong answer",
+        "item_type": "lucky_clover",
+        "price_gems": 20,
+        "effects": {"chance": 0.3},
+        "is_available": True,
+    },
+    {
+        "name": "Score Multiplier",
+        "description": "Double your in-game score for the rest of this session",
+        "item_type": "score_multiplier",
+        "price_gems": 22,
+        "effects": {"multiplier": 2},
+        "is_available": True,
+    },
+    {
+        "name": "Pair Swap",
+        "description": "Undo one wrong match in Matching Game for a free retry",
+        "item_type": "pair_swap",
+        "price_gems": 10,
+        "effects": {},
+        "is_available": True,
+    },
+]
+
+GAME_POWERUP_ITEM_TYPES: list[str] = [
+    "time_freeze",
+    "extra_time",
+    "skip_token",
+    "reveal_hint",
+    "translate_hint",
+    "mistake_shield",
+    "extra_heart",
+    "lucky_clover",
+    "score_multiplier",
+    "pair_swap",
 ]
 
 _AVATAR_SEEDS_BY_TIER = {
diff --git a/backend-service/app/core/token_blacklist.py b/backend-service/app/core/token_blacklist.py
index 45d6baed..13e7f964 100644
--- a/backend-service/app/core/token_blacklist.py
+++ b/backend-service/app/core/token_blacklist.py
@@ -60,7 +60,7 @@ async def add(
                 # Add buffer to ensure blacklist outlives token
                 ttl_seconds = max(ttl_seconds + 60, 60)
             else:
-                ttl_seconds = settings.TOKEN_BLACKLIST_EXPIRE_HOURS * 3600
+                ttl_seconds = settings.ACCESS_TOKEN_EXPIRE_MINUTES * 60
             
             # Use token hash as key (first 16 chars) for efficiency
             token_key = cls._get_key(token)
diff --git a/backend-service/app/crud/course.py b/backend-service/app/crud/course.py
index d7cf2e4a..43f64d48 100644
--- a/backend-service/app/crud/course.py
+++ b/backend-service/app/crud/course.py
@@ -6,8 +6,8 @@
 """
 
 from typing import List, Optional
-from sqlalchemy import select, func, and_, or_, text
-from sqlalchemy.orm import Session, selectinload
+from sqlalchemy import String, case, cast, select, func, and_
+from sqlalchemy.orm import selectinload
 from sqlalchemy.ext.asyncio import AsyncSession
 import uuid
 
@@ -16,6 +16,14 @@
 from app.schemas.course import CourseCreate, CourseUpdate, UnitCreate, UnitUpdate, LessonCreate, LessonUpdate
 
 
+def _seed_first_ordering():
+    """Return a portable expression that sorts seeded courses first."""
+    return case(
+        (cast(Course.tags, String).like('%"seed"%'), 0),
+        else_=1,
+    )
+
+
 # =====================
 # Course CRUD
 # =====================
@@ -79,7 +87,7 @@ async def get_courses(
         
         # Get paginated results — seed/curated courses first, then crawled
         query = query.order_by(
-            text("CASE WHEN tags @> '[\"seed\"]'::jsonb THEN 0 ELSE 1 END"),
+            _seed_first_ordering(),
             Course.created_at.asc()
         ).offset(skip).limit(limit)
         result = await db.execute(query)
diff --git a/backend-service/app/crud/gamification.py b/backend-service/app/crud/gamification.py
index 91c80214..1a1829c0 100644
--- a/backend-service/app/crud/gamification.py
+++ b/backend-service/app/crud/gamification.py
@@ -16,6 +16,7 @@
 )
 from app.models.user import User
 from app.crud.leaderboard import competition_rank
+from app.core.cache import build_cache_key, delete_cached
 
 
 # ============================================================================
@@ -207,6 +208,7 @@ async def add_gems(
             await db.refresh(wallet)
         else:
             await db.flush()
+        await delete_cached(build_cache_key("wallet", user_id=str(user_id)))
         
         return wallet, transaction
     
@@ -256,6 +258,7 @@ async def spend_gems(
             await db.refresh(wallet)
         else:
             await db.flush()
+        await delete_cached(build_cache_key("wallet", user_id=str(user_id)))
         
         return wallet, transaction
     
diff --git a/backend-service/app/crud/vocabulary.py b/backend-service/app/crud/vocabulary.py
index aa275e2c..5aa576ee 100644
--- a/backend-service/app/crud/vocabulary.py
+++ b/backend-service/app/crud/vocabulary.py
@@ -135,7 +135,10 @@ async def get_vocabulary_items(
             func.lower(VocabularyItem.word),
             VocabularyItem.id,
         )
-        
+
+        if not tag:
+            query = query.offset(offset).limit(limit)
+
         result = await db.execute(query)
         items = [
             item
@@ -150,7 +153,7 @@ async def get_vocabulary_items(
                 if expected_tag in normalize_all_tags(item.tags)
             ]
             return items[offset : offset + limit]
-        return items[offset : offset + limit]
+        return items
     
     async def search_vocabulary(
         self,
@@ -270,6 +273,29 @@ async def get_user_vocabulary_list(
 
         result = await db.execute(query)
         return list(result.scalars().all())
+
+    async def count_user_vocabulary(
+        self,
+        db: AsyncSession,
+        user_id: uuid.UUID,
+        status: Optional[VocabularyStatus] = None,
+    ) -> int:
+        """Count visible vocabulary entries in a user's collection."""
+        query = (
+            select(func.count(UserVocabulary.id))
+            .join(
+                VocabularyItem,
+                VocabularyItem.id == UserVocabulary.vocabulary_id,
+            )
+            .where(UserVocabulary.user_id == user_id)
+            .where(*_valid_definition_conditions())
+        )
+
+        if status:
+            query = query.where(UserVocabulary.status == status)
+
+        result = await db.execute(query)
+        return result.scalar() or 0
     
     async def add_to_collection(
         self,
diff --git a/backend-service/app/main.py b/backend-service/app/main.py
index 8baef223..7a91d328 100644
--- a/backend-service/app/main.py
+++ b/backend-service/app/main.py
@@ -48,7 +48,9 @@
     gamification_router,
 )
 from app.routes.learning import router as learning_router
-from app.routes.admin import router as admin_router
+from app.routes.admin_courses import router as admin_courses_router
+from app.routes.admin_gamification import router as admin_gamification_router
+from app.routes.admin_system import router as admin_system_router
 from app.routes.content_agent import router as content_agent_router
 from app.routes.notification_campaign import router as notification_campaign_router
 from app.routes.ranking_agent import router as ranking_agent_router
@@ -70,6 +72,8 @@
 from app.routes.notifications import router as notifications_router
 from app.routes.reminders import router as reminders_router
 from app.routes.referral import router as referral_router
+from app.routes.mistakes import router as mistakes_router
+from app.routes.well_known import router as well_known_router
 from app.schemas.common import ErrorResponse, ErrorDetail, ErrorCodes
 
 # Setup logging
@@ -272,6 +276,7 @@ async def limit_request_body(request: Request, call_next):
     return await call_next(request)
 
 # Include routers
+app.include_router(well_known_router)
 app.include_router(health_router, tags=["Health"])
 app.include_router(auth_router, prefix=f"{settings.API_V1_PREFIX}/auth", tags=["Authentication"])
 app.include_router(users_router, prefix=f"{settings.API_V1_PREFIX}/users", tags=["Users"])
@@ -282,7 +287,9 @@ async def limit_request_body(request: Request, call_next):
 app.include_router(vocabulary_router, prefix=f"{settings.API_V1_PREFIX}/vocabulary", tags=["Vocabulary"])
 app.include_router(gamification_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Gamification"])
 app.include_router(challenges_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Challenges"])
-app.include_router(admin_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Admin"])
+app.include_router(admin_courses_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Admin"])
+app.include_router(admin_gamification_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Admin"])
+app.include_router(admin_system_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Admin"])
 app.include_router(content_agent_router, prefix=f"{settings.API_V1_PREFIX}")
 app.include_router(notification_campaign_router, prefix=f"{settings.API_V1_PREFIX}")
 app.include_router(ranking_agent_router, prefix=f"{settings.API_V1_PREFIX}")
@@ -293,6 +300,7 @@ async def limit_request_body(request: Request, call_next):
 app.include_router(user_management_router, prefix=f"{settings.API_V1_PREFIX}", tags=["User Management"])
 app.include_router(reminders_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Reminder Preferences"])
 app.include_router(notifications_router, prefix=f"{settings.API_V1_PREFIX}/notifications", tags=["Notifications"])
+app.include_router(mistakes_router, prefix=f"{settings.API_V1_PREFIX}", tags=["Mistakes"])
 
 # Content Features
 app.include_router(youtube_router, prefix=f"{settings.API_V1_PREFIX}", tags=["YouTube"])
diff --git a/backend-service/app/models/__init__.py b/backend-service/app/models/__init__.py
index 93d971d9..d82ccc55 100644
--- a/backend-service/app/models/__init__.py
+++ b/backend-service/app/models/__init__.py
@@ -80,6 +80,9 @@
 # Reminder models
 from app.models.reminder import ReminderDelivery, UserReminderPreference
 
+# Mistake notebook models
+from app.models.mistake import MistakeNotebookEntry
+
 # API Cache (Phase 0 — Infrastructure)
 from app.models.api_cache import APICacheEntry
 
@@ -164,6 +167,8 @@
     # Reminder
     "ReminderDelivery",
     "UserReminderPreference",
+    # Mistake notebook
+    "MistakeNotebookEntry",
     # API Cache (Phase 0)
     "APICacheEntry",
     # Games (Phase 3)
diff --git a/backend-service/app/models/content.py b/backend-service/app/models/content.py
index fa2b6ef4..0bff17c3 100644
--- a/backend-service/app/models/content.py
+++ b/backend-service/app/models/content.py
@@ -24,8 +24,14 @@ class GrammarItem(Base):
     tags: Mapped[dict | None] = mapped_column(PortableJSON, nullable=True)  # list of tags
     is_active: Mapped[bool] = mapped_column(Boolean, default=True)
 
-    created_at: Mapped[datetime] = mapped_column(TZDateTime, default=lambda: datetime.now(timezone.utc))
-    updated_at: Mapped[datetime] = mapped_column(TZDateTime, default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
+    created_at: Mapped[datetime] = mapped_column(
+        TZDateTime, default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        TZDateTime,
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )
 
     questions = relationship("QuestionItem", back_populates="grammar", lazy="noload")
 
@@ -52,8 +58,14 @@ class QuestionItem(Base):
         GUID(), ForeignKey("grammar_items.id", ondelete="SET NULL"), nullable=True, index=True
     )
 
-    created_at: Mapped[datetime] = mapped_column(TZDateTime, default=lambda: datetime.now(timezone.utc))
-    updated_at: Mapped[datetime] = mapped_column(TZDateTime, default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
+    created_at: Mapped[datetime] = mapped_column(
+        TZDateTime, default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        TZDateTime,
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )
 
     grammar = relationship("GrammarItem", back_populates="questions", lazy="selectin")
 
@@ -64,6 +76,7 @@ class QuestionItem(Base):
 
 
 class TestExam(Base):
+    __test__ = False
     __tablename__ = "test_exams"
 
     id: Mapped[uuid.UUID] = mapped_column(GUID(), primary_key=True, default=uuid.uuid4)
@@ -72,11 +85,19 @@ class TestExam(Base):
     level: Mapped[str] = mapped_column(String(20), nullable=False, default="A1")
     duration_minutes: Mapped[int] = mapped_column(Integer, nullable=False, default=20)
     passing_score: Mapped[int] = mapped_column(Integer, nullable=False, default=70)
-    question_ids: Mapped[dict | None] = mapped_column(PortableJSON, nullable=True)  # list of question UUIDs
+    question_ids: Mapped[dict | None] = mapped_column(
+        PortableJSON, nullable=True
+    )  # list of question UUIDs
     is_published: Mapped[bool] = mapped_column(Boolean, default=False)
 
-    created_at: Mapped[datetime] = mapped_column(TZDateTime, default=lambda: datetime.now(timezone.utc))
-    updated_at: Mapped[datetime] = mapped_column(TZDateTime, default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
+    created_at: Mapped[datetime] = mapped_column(
+        TZDateTime, default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        TZDateTime,
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )
 
     __table_args__ = (
         Index("ix_test_exams_level", "level"),
diff --git a/backend-service/app/models/mistake.py b/backend-service/app/models/mistake.py
new file mode 100644
index 00000000..09233a43
--- /dev/null
+++ b/backend-service/app/models/mistake.py
@@ -0,0 +1,76 @@
+"""Synced mistake notebook models."""
+
+import uuid
+from datetime import UTC, datetime
+
+from sqlalchemy import ForeignKey, Index, Integer, String, Text, UniqueConstraint
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.core.database import Base
+from app.core.db_types import GUID, PortableJSON, TZDateTime
+
+
+class MistakeNotebookEntry(Base):
+    """A user-owned mistake captured from quizzes, games, reading, or voice practice."""
+
+    __tablename__ = "mistake_notebook_entries"
+
+    id: Mapped[uuid.UUID] = mapped_column(GUID(), primary_key=True, default=uuid.uuid4)
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        GUID(),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+        index=True,
+    )
+    client_id: Mapped[str | None] = mapped_column(String(128), nullable=True)
+    source_type: Mapped[str] = mapped_column(String(80), nullable=False)
+    source_id: Mapped[str] = mapped_column(String(255), nullable=False)
+    source_title: Mapped[str] = mapped_column(String(500), default="", nullable=False)
+    question: Mapped[str] = mapped_column(Text, nullable=False)
+    question_hash: Mapped[str] = mapped_column(String(64), nullable=False)
+    selected_answer: Mapped[str] = mapped_column(Text, default="", nullable=False)
+    correct_answer: Mapped[str] = mapped_column(Text, default="", nullable=False)
+    explanation: Mapped[str] = mapped_column(Text, default="", nullable=False)
+    skill: Mapped[str] = mapped_column(String(80), default="general", nullable=False)
+    status: Mapped[str] = mapped_column(String(20), default="open", nullable=False)
+    review_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
+    attempt_count: Mapped[int] = mapped_column(Integer, default=1, nullable=False)
+    extra_data: Mapped[dict | None] = mapped_column(PortableJSON, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        TZDateTime,
+        default=lambda: datetime.now(UTC),
+        nullable=False,
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        TZDateTime,
+        default=lambda: datetime.now(UTC),
+        onupdate=lambda: datetime.now(UTC),
+        nullable=False,
+    )
+    reviewed_at: Mapped[datetime | None] = mapped_column(TZDateTime, nullable=True)
+    last_seen_at: Mapped[datetime] = mapped_column(
+        TZDateTime,
+        default=lambda: datetime.now(UTC),
+        nullable=False,
+    )
+
+    __table_args__ = (
+        UniqueConstraint(
+            "user_id",
+            "client_id",
+            name="uq_mistake_notebook_entries_user_client_id",
+        ),
+        Index(
+            "ix_mistake_notebook_entries_user_status_created",
+            "user_id",
+            "status",
+            "created_at",
+        ),
+        Index(
+            "ix_mistake_notebook_entries_user_source_question_hash",
+            "user_id",
+            "source_type",
+            "source_id",
+            "question_hash",
+        ),
+    )
diff --git a/backend-service/app/routes/admin.py b/backend-service/app/routes/admin.py
deleted file mode 100644
index 4186e43d..00000000
--- a/backend-service/app/routes/admin.py
+++ /dev/null
@@ -1,2152 +0,0 @@
-"""
-Admin API Routes — DEPRECATED
-
-This module has been split into:
-  app/routes/admin_courses.py      — courses, units, lessons, vocab, grammar, questions, test-exams
-  app/routes/admin_gamification.py — achievements, shop
-  app/routes/admin_system.py       — seed endpoint, system-info, quota
-
-main.py now registers admin_courses_router, admin_gamification_router, admin_system_router directly.
-This file is kept only as a reference and is no longer imported.
-"""
-
-from typing import Optional, List
-from uuid import UUID
-from fastapi import APIRouter, Depends, HTTPException, Query, status, UploadFile, File
-from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy import select, or_, func, desc
-
-from app.core.database import get_db
-from app.core.dependencies import get_current_admin, get_current_super_admin
-from app.models.user import User
-from app.models.rbac import Role
-from app.models.course import Course, Unit, Lesson
-from app.models.course_category import CourseCategory
-from app.models.vocabulary import VocabularyItem
-from app.models.gamification import Achievement, ShopItem
-from app.models.content import GrammarItem, QuestionItem, TestExam
-from app.crud.course import CourseCRUD, UnitCRUD, LessonCRUD
-from app.schemas.course import (
-    CourseCreate, CourseUpdate, CourseResponse,
-    UnitCreate, UnitUpdate, UnitResponse,
-    LessonCreate, LessonUpdate, LessonResponse, LessonDetailResponse
-)
-from app.schemas.response import ApiResponse
-from app.schemas.content import (
-    GrammarCreate, GrammarUpdate, GrammarResponse,
-    QuestionCreate, QuestionUpdate, QuestionResponse,
-    TestExamCreate, TestExamUpdate, TestExamResponse
-)
-from app.schemas.user import AdminUserUpdate, AdminUserListItem
-
-router = APIRouter(prefix="/admin", tags=["Admin"])
-
-
-# ============================================================================
-# RBAC: Admin guard — requires role.level >= 1 (admin or super_admin)
-# Imported from app.core.dependencies.get_current_admin
-# ============================================================================
-
-# Alias for backward compatibility in this file
-require_admin = get_current_admin
-
-
-# ============================================================================
-# Course Admin CRUD
-# ============================================================================
-
-@router.get("/courses", response_model=ApiResponse[dict])
-async def list_courses_admin(
-    page: int = Query(1, ge=1),
-    page_size: int = Query(20, ge=1, le=100),
-    search: Optional[str] = Query(None),
-    level: Optional[str] = Query(None),
-    is_published: Optional[bool] = Query(None),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """List all courses (including unpublished) for admin management."""
-    query = select(Course)
-    filters = []
-    if search:
-        pattern = f"%{search}%"
-        filters.append(or_(Course.title.ilike(pattern), Course.description.ilike(pattern)))
-    if level:
-        filters.append(Course.level == level)
-    if is_published is not None:
-        filters.append(Course.is_published == is_published)
-    if filters:
-        from sqlalchemy import and_
-        query = query.where(and_(*filters))
-    
-    count_q = select(func.count()).select_from(query.subquery())
-    total = await db.scalar(count_q) or 0
-    
-    query = query.order_by(desc(Course.updated_at))
-    offset = (page - 1) * page_size
-    result = await db.execute(query.offset(offset).limit(page_size))
-    courses = result.scalars().all()
-    
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(courses)} courses",
-        data={
-            "courses": [CourseResponse.model_validate(c).model_dump() for c in courses],
-            "total": total,
-            "page": page,
-            "page_size": page_size,
-            "total_pages": (total + page_size - 1) // page_size,
-        }
-    )
-
-
-@router.get("/units", response_model=ApiResponse[List[dict]])
-async def list_units_admin(
-    course_id: Optional[UUID] = Query(None, description="Filter units by course"),
-    search: Optional[str] = Query(None, description="Search units by title or description"),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """List all units, optionally filtered by course or searched by title/description."""
-    query = select(Unit)
-    if course_id:
-        query = query.where(Unit.course_id == course_id)
-    if search:
-        query = query.where(
-            or_(
-                Unit.title.ilike(f"%{search}%"),
-                Unit.description.ilike(f"%{search}%")
-            )
-        )
-    query = query.order_by(Unit.order_index)
-    result = await db.execute(query)
-    units = result.scalars().all()
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(units)} units",
-        data=[UnitResponse.model_validate(u).model_dump() for u in units]
-    )
-
-
-@router.get("/lessons", response_model=ApiResponse[List[dict]])
-async def list_lessons_admin(
-    unit_id: Optional[UUID] = Query(None, description="Filter by unit"),
-    course_id: Optional[UUID] = Query(None, description="Filter by course"),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """List lessons filtered by unit or course."""
-    query = select(Lesson)
-    if unit_id:
-        query = query.where(Lesson.unit_id == unit_id)
-    elif course_id:
-        query = query.where(Lesson.course_id == course_id)
-    query = query.order_by(Lesson.order_index)
-    result = await db.execute(query)
-    lessons = result.scalars().all()
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(lessons)} lessons",
-        data=[LessonResponse.model_validate(l).model_dump() for l in lessons]
-    )
-
-
-@router.post("/courses", response_model=ApiResponse[CourseResponse])
-async def create_course(
-    course: CourseCreate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Create a new course.
-    
-    Admin only endpoint.
-    """
-    new_course = await CourseCRUD.create_course(db, course)
-    
-    return ApiResponse(
-        success=True,
-        message="Course created successfully",
-        data=CourseResponse.model_validate(new_course)
-    )
-
-
-@router.put("/courses/{course_id}", response_model=ApiResponse[CourseResponse])
-async def update_course(
-    course_id: UUID,
-    course_update: CourseUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Update an existing course.
-    
-    Admin only endpoint.
-    """
-    updated_course = await CourseCRUD.update_course(db, course_id, course_update)
-    
-    if not updated_course:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Course not found"
-        )
-    
-    return ApiResponse(
-        success=True,
-        message="Course updated successfully",
-        data=CourseResponse.model_validate(updated_course)
-    )
-
-
-@router.delete("/courses/{course_id}", response_model=ApiResponse[dict])
-async def delete_course(
-    course_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Delete a course (soft delete - unpublish).
-    
-    Admin only endpoint.
-    """
-    success = await CourseCRUD.delete_course(db, course_id)
-    
-    if not success:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Course not found"
-        )
-    
-    return ApiResponse(
-        success=True,
-        message="Course deleted successfully",
-        data={"deleted": True, "course_id": str(course_id)}
-    )
-
-
-# ============================================================================
-# Unit Admin CRUD
-# ============================================================================
-
-@router.post("/units", response_model=ApiResponse[UnitResponse])
-async def create_unit(
-    unit: UnitCreate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Create a new unit within a course.
-    
-    Admin only endpoint.
-    """
-    # Verify course exists
-    course = await CourseCRUD.get_course(db, unit.course_id)
-    if not course:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Course not found"
-        )
-    
-    new_unit = await UnitCRUD.create_unit(db, unit)
-    
-    return ApiResponse(
-        success=True,
-        message="Unit created successfully",
-        data=UnitResponse.model_validate(new_unit)
-    )
-
-
-@router.put("/units/{unit_id}", response_model=ApiResponse[UnitResponse])
-async def update_unit(
-    unit_id: UUID,
-    unit_update: UnitUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Update an existing unit.
-    
-    Admin only endpoint.
-    """
-    updated_unit = await UnitCRUD.update_unit(db, unit_id, unit_update)
-    
-    if not updated_unit:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Unit not found"
-        )
-    
-    return ApiResponse(
-        success=True,
-        message="Unit updated successfully",
-        data=UnitResponse.model_validate(updated_unit)
-    )
-
-
-@router.delete("/units/{unit_id}", response_model=ApiResponse[dict])
-async def delete_unit(
-    unit_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Delete a unit (cascade deletes lessons).
-    
-    Admin only endpoint.
-    """
-    success = await UnitCRUD.delete_unit(db, unit_id)
-    
-    if not success:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Unit not found"
-        )
-    
-    return ApiResponse(
-        success=True,
-        message="Unit deleted successfully",
-        data={"deleted": True, "unit_id": str(unit_id)}
-    )
-
-
-# ============================================================================
-# Lesson Admin CRUD
-# ============================================================================
-
-@router.post("/lessons", response_model=ApiResponse[LessonResponse])
-async def create_lesson(
-    lesson: LessonCreate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Create a new lesson within a unit.
-    
-    Admin only endpoint.
-    """
-    # Verify unit exists
-    unit = await UnitCRUD.get_unit(db, lesson.unit_id)
-    if not unit:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Unit not found"
-        )
-    
-    new_lesson = await LessonCRUD.create_lesson(db, lesson)
-    
-    return ApiResponse(
-        success=True,
-        message="Lesson created successfully",
-        data=LessonResponse.model_validate(new_lesson)
-    )
-
-
-@router.put("/lessons/{lesson_id}", response_model=ApiResponse[LessonResponse])
-async def update_lesson(
-    lesson_id: UUID,
-    lesson_update: LessonUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Update an existing lesson.
-    
-    Admin only endpoint.
-    """
-    updated_lesson = await LessonCRUD.update_lesson(db, lesson_id, lesson_update)
-    
-    if not updated_lesson:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Lesson not found"
-        )
-    
-    return ApiResponse(
-        success=True,
-        message="Lesson updated successfully",
-        data=LessonResponse.model_validate(updated_lesson)
-    )
-
-
-@router.delete("/lessons/{lesson_id}", response_model=ApiResponse[dict])
-async def delete_lesson(
-    lesson_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Delete a lesson.
-    
-    Admin only endpoint.
-    """
-    success = await LessonCRUD.delete_lesson(db, lesson_id)
-    
-    if not success:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Lesson not found"
-        )
-    
-    return ApiResponse(
-        success=True,
-        message="Lesson deleted successfully",
-        data={"deleted": True, "lesson_id": str(lesson_id)}
-    )
-
-
-@router.get("/lessons/{lesson_id}", response_model=ApiResponse[dict])
-async def get_lesson_detail(
-    lesson_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """Get a single lesson with full content/exercises (admin only)."""
-    lesson = await LessonCRUD.get_lesson(db, lesson_id)
-    if not lesson:
-        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Lesson not found")
-
-    data = LessonDetailResponse.model_validate(lesson).model_dump()
-    return ApiResponse(success=True, message="Lesson retrieved", data=data)
-
-
-class LessonContentUpdate(LessonUpdate):
-    """Dedicated schema for updating lesson exercises content."""
-    pass
-
-
-@router.put("/lessons/{lesson_id}/content", response_model=ApiResponse[dict])
-async def update_lesson_content(
-    lesson_id: UUID,
-    payload: LessonContentUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """Update lesson exercises and estimated_minutes (admin only)."""
-    lesson = await LessonCRUD.get_lesson(db, lesson_id)
-    if not lesson:
-        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Lesson not found")
-
-    update_data = payload.model_dump(exclude_unset=True)
-
-    # Derive total_exercises from exercises array inside content
-    if "content" in update_data and update_data["content"]:
-        exercises = update_data["content"].get("exercises", [])
-        update_data["total_exercises"] = len(exercises)
-
-    for field, value in update_data.items():
-        setattr(lesson, field, value)
-
-    await db.commit()
-    await db.refresh(lesson)
-
-    data = LessonDetailResponse.model_validate(lesson).model_dump()
-    return ApiResponse(success=True, message="Lesson content updated", data=data)
-
-
-# ============================================================================
-# Vocabulary Admin CRUD
-# ============================================================================
-
-@router.get("/vocabulary", response_model=ApiResponse[List[dict]])
-async def list_vocabulary(
-    limit: int = Query(50, ge=1, le=100),
-    offset: int = Query(0, ge=0),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    List all vocabulary items.
-    
-    Admin only endpoint.
-    """
-    result = await db.execute(
-        select(VocabularyItem)
-        .order_by(VocabularyItem.word)
-        .limit(limit)
-        .offset(offset)
-    )
-    items = result.scalars().all()
-    
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(items)} vocabulary items",
-        data=[{
-            "id": str(item.id),
-            "word": item.word,
-            "definition": getattr(item, "definition", None),
-            "translation": item.translation,
-            "part_of_speech": item.part_of_speech,
-            "pronunciation": getattr(item, "pronunciation", None),
-            "difficulty_level": item.difficulty_level,
-        } for item in items]
-    )
-
-
-@router.post("/vocabulary", response_model=ApiResponse[dict])
-async def create_vocabulary(
-    word: str,
-    definition: str,
-    translation: str,
-    part_of_speech: str = "noun",
-    pronunciation: Optional[str] = None,
-    difficulty_level: str = "A1",
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Create a new vocabulary item.
-    
-    Args:
-        word: The vocabulary word
-        definition: English definition
-        translation: Vietnamese translation
-        part_of_speech: Part of speech (noun, verb, adjective, etc.)
-        pronunciation: IPA pronunciation
-        difficulty_level: CEFR level (A1, A2, B1, B2, C1, C2)
-    
-    Admin only endpoint.
-    """
-    vocab = VocabularyItem(
-        word=word,
-        definition=definition,
-        translation={"vi": translation},  # JSON format as per model
-        part_of_speech=part_of_speech,
-        pronunciation=pronunciation,
-        difficulty_level=difficulty_level
-    )
-    db.add(vocab)
-    await db.commit()
-    await db.refresh(vocab)
-    
-    return ApiResponse(
-        success=True,
-        message="Vocabulary created successfully",
-        data={
-            "id": str(vocab.id),
-            "word": vocab.word,
-            "definition": vocab.definition,
-            "translation": vocab.translation
-        }
-    )
-
-
-@router.delete("/vocabulary/{vocab_id}", response_model=ApiResponse[dict])
-async def delete_vocabulary(
-    vocab_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Delete a vocabulary item.
-    
-    Admin only endpoint.
-    """
-    result = await db.execute(
-        select(VocabularyItem).where(VocabularyItem.id == vocab_id)
-    )
-    vocab = result.scalar_one_or_none()
-    
-    if not vocab:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Vocabulary not found"
-        )
-    
-    await db.delete(vocab)
-    await db.commit()
-    
-    return ApiResponse(
-        success=True,
-        message="Vocabulary deleted successfully",
-        data={"deleted": True, "vocab_id": str(vocab_id)}
-    )
-
-
-@router.put("/vocabulary/{vocab_id}", response_model=ApiResponse[dict])
-async def update_vocabulary(
-    vocab_id: UUID,
-    word: Optional[str] = None,
-    definition: Optional[str] = None,
-    translation: Optional[str] = None,
-    part_of_speech: Optional[str] = None,
-    pronunciation: Optional[str] = None,
-    difficulty_level: Optional[str] = None,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """Update a vocabulary item."""
-    result = await db.execute(
-        select(VocabularyItem).where(VocabularyItem.id == vocab_id)
-    )
-    vocab = result.scalar_one_or_none()
-    if not vocab:
-        raise HTTPException(status_code=404, detail="Vocabulary not found")
-    
-    if word is not None: vocab.word = word
-    if definition is not None: vocab.definition = definition
-    if translation is not None: vocab.translation = {"vi": translation}
-    if part_of_speech is not None: vocab.part_of_speech = part_of_speech
-    if pronunciation is not None: vocab.pronunciation = pronunciation
-    if difficulty_level is not None: vocab.difficulty_level = difficulty_level
-    
-    await db.commit()
-    await db.refresh(vocab)
-    
-    return ApiResponse(
-        success=True,
-        message="Vocabulary updated successfully",
-        data={
-            "id": str(vocab.id),
-            "word": vocab.word,
-            "definition": vocab.definition,
-            "translation": vocab.translation,
-            "part_of_speech": vocab.part_of_speech,
-            "difficulty_level": vocab.difficulty_level,
-        }
-    )
-
-
-@router.post("/vocabulary/bulk-import", response_model=ApiResponse[dict])
-async def bulk_import_vocabulary(
-    file: UploadFile = File(...),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Bulk import vocabulary from CSV file.
-    
-    CSV format: word,definition,translation,part_of_speech,pronunciation,difficulty_level
-    First row must be headers.
-    """
-    import csv
-    import io
-    
-    if not file.filename or not file.filename.endswith(".csv"):
-        raise HTTPException(status_code=400, detail="Only CSV files are supported")
-    
-    # Limit CSV file size to 10MB to prevent memory exhaustion
-    content = await file.read()
-    if len(content) > 10 * 1024 * 1024:
-        raise HTTPException(status_code=413, detail="File too large. Maximum 10MB allowed.")
-    text = content.decode("utf-8-sig")  # Handle BOM
-    reader = csv.DictReader(io.StringIO(text))
-    
-    created = 0
-    skipped = 0
-    errors = []
-    
-    for row_num, row in enumerate(reader, start=2):
-        word = row.get("word", "").strip()
-        definition = row.get("definition", "").strip()
-        translation = row.get("translation", "").strip()
-        
-        if not word:
-            skipped += 1
-            continue
-        
-        # Check duplicate
-        existing = await db.scalar(
-            select(func.count()).where(VocabularyItem.word == word)
-        )
-        if existing:
-            skipped += 1
-            continue
-        
-        try:
-            vocab = VocabularyItem(
-                word=word,
-                definition=definition or word,
-                translation={"vi": translation} if translation else {},
-                part_of_speech=row.get("part_of_speech", "noun").strip() or "noun",
-                pronunciation=row.get("pronunciation", "").strip() or None,
-                difficulty_level=row.get("difficulty_level", "A1").strip() or "A1",
-            )
-            db.add(vocab)
-            created += 1
-        except Exception as e:
-            errors.append(f"Row {row_num}: {str(e)}")
-    
-    await db.commit()
-    
-    return ApiResponse(
-        success=True,
-        message=f"Imported {created} words, skipped {skipped} duplicates",
-        data={
-            "created": created,
-            "skipped": skipped,
-            "errors": errors[:10],  # Limit error list
-        }
-    )
-
-
-# ============================================================================
-# Badge Image Upload
-# ============================================================================
-
-@router.post("/upload/badge", response_model=ApiResponse[dict])
-async def upload_badge_image(
-    file: UploadFile = File(...),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Upload a badge image. Returns the URL path to the uploaded file.
-    Accepts PNG, JPG, WEBP images up to 2MB.
-    """
-    import os
-    from pathlib import Path
-
-    # Validate file type — SVG excluded to prevent XSS
-    allowed_types = ["image/png", "image/jpeg", "image/webp"]
-    if file.content_type not in allowed_types:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=f"Invalid file type: {file.content_type}. Allowed: {', '.join(allowed_types)}"
-        )
-
-    # Read file and check size (2MB limit)
-    contents = await file.read()
-    if len(contents) > 2 * 1024 * 1024:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail="File too large. Maximum 2MB allowed."
-        )
-
-    # Save to static/badges/
-    static_dir = Path(__file__).resolve().parent.parent.parent / "static" / "badges"
-    static_dir.mkdir(parents=True, exist_ok=True)
-
-    # Generate UUID-based filename to prevent path traversal and name collisions
-    import uuid
-    allowed_extensions = {".png", ".jpg", ".jpeg", ".webp"}
-    original_ext = Path(file.filename or "badge.png").suffix.lower()
-    if original_ext not in allowed_extensions:
-        original_ext = ".png"
-    safe_name = f"{uuid.uuid4().hex}{original_ext}"
-    filepath = static_dir / safe_name
-
-    with open(filepath, "wb") as f:
-        f.write(contents)
-
-    badge_url = f"/static/badges/{filepath.name}"
-
-    return ApiResponse(
-        success=True,
-        message="Badge image uploaded successfully",
-        data={
-            "url": badge_url,
-            "filename": filepath.name,
-        }
-    )
-
-
-# ============================================================================
-# Achievement Admin CRUD
-# ============================================================================
-
-@router.get("/achievements", response_model=ApiResponse[List[dict]])
-async def list_achievements_admin(
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    List all achievements (admin view).
-    
-    Admin only endpoint.
-    """
-    result = await db.execute(
-        select(Achievement).order_by(Achievement.category, Achievement.name)
-    )
-    achievements = result.scalars().all()
-    
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(achievements)} achievements",
-        data=[{
-            "id": str(a.id),
-            "slug": a.slug,
-            "name": a.name,
-            "description": a.description,
-            "badge_icon": a.badge_icon,
-            "badge_color": a.badge_color,
-            "condition_type": a.condition_type,
-            "condition_value": a.condition_value,
-            "category": a.category,
-            "rarity": a.rarity,
-            "xp_reward": a.xp_reward,
-            "gems_reward": a.gems_reward,
-            "is_hidden": a.is_hidden
-        } for a in achievements]
-    )
-
-
-@router.post("/achievements", response_model=ApiResponse[dict])
-async def create_achievement(
-    name: str,
-    description: str,
-    condition_type: str,
-    condition_value: int = 1,
-    category: str = "special",
-    rarity: str = "common",
-    xp_reward: int = 0,
-    gems_reward: int = 0,
-    is_hidden: bool = False,
-    badge_icon: Optional[str] = None,
-    badge_color: Optional[str] = None,
-    slug: Optional[str] = None,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Create a new achievement.
-    
-    Admin only endpoint.
-    """
-    achievement = Achievement(
-        name=name,
-        slug=slug,
-        description=description,
-        condition_type=condition_type,
-        condition_value=condition_value,
-        category=category,
-        rarity=rarity,
-        xp_reward=xp_reward,
-        gems_reward=gems_reward,
-        is_hidden=is_hidden,
-        badge_icon=badge_icon,
-        badge_color=badge_color
-    )
-    db.add(achievement)
-    await db.commit()
-    await db.refresh(achievement)
-    
-    return ApiResponse(
-        success=True,
-        message="Achievement created successfully",
-        data={
-            "id": str(achievement.id),
-            "name": achievement.name,
-            "category": achievement.category
-        }
-    )
-
-
-@router.put("/achievements/{achievement_id}", response_model=ApiResponse[dict])
-async def update_achievement(
-    achievement_id: UUID,
-    name: Optional[str] = None,
-    description: Optional[str] = None,
-    condition_type: Optional[str] = None,
-    condition_value: Optional[int] = None,
-    category: Optional[str] = None,
-    rarity: Optional[str] = None,
-    xp_reward: Optional[int] = None,
-    gems_reward: Optional[int] = None,
-    is_hidden: Optional[bool] = None,
-    badge_icon: Optional[str] = None,
-    badge_color: Optional[str] = None,
-    slug: Optional[str] = None,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """Update an achievement. Admin only."""
-    result = await db.execute(
-        select(Achievement).where(Achievement.id == achievement_id)
-    )
-    achievement = result.scalar_one_or_none()
-    if not achievement:
-        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Achievement not found")
-
-    for field, value in {
-        "name": name, "description": description, "condition_type": condition_type,
-        "condition_value": condition_value, "category": category, "rarity": rarity,
-        "xp_reward": xp_reward, "gems_reward": gems_reward, "is_hidden": is_hidden,
-        "badge_icon": badge_icon, "badge_color": badge_color, "slug": slug,
-    }.items():
-        if value is not None:
-            setattr(achievement, field, value)
-
-    await db.commit()
-    await db.refresh(achievement)
-
-    return ApiResponse(
-        success=True,
-        message="Achievement updated successfully",
-        data={
-            "id": str(achievement.id),
-            "name": achievement.name,
-            "category": achievement.category,
-            "rarity": achievement.rarity,
-        }
-    )
-
-
-@router.delete("/achievements/{achievement_id}", response_model=ApiResponse[dict])
-async def delete_achievement(
-    achievement_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Delete an achievement.
-    
-    Admin only endpoint.
-    """
-    result = await db.execute(
-        select(Achievement).where(Achievement.id == achievement_id)
-    )
-    achievement = result.scalar_one_or_none()
-    
-    if not achievement:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Achievement not found"
-        )
-    
-    await db.delete(achievement)
-    await db.commit()
-    
-    return ApiResponse(
-        success=True,
-        message="Achievement deleted successfully",
-        data={"deleted": True, "achievement_id": str(achievement_id)}
-    )
-
-
-# ============================================================================
-# Shop Admin CRUD
-# ============================================================================
-
-@router.get("/shop", response_model=ApiResponse[List[dict]])
-async def list_shop_items_admin(
-    include_unavailable: bool = Query(False),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    List all shop items (admin view).
-    
-    Admin only endpoint.
-    """
-    query = select(ShopItem).order_by(ShopItem.item_type, ShopItem.price_gems)
-    if not include_unavailable:
-        query = query.where(ShopItem.is_available == True)
-    
-    result = await db.execute(query)
-    items = result.scalars().all()
-    
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(items)} shop items",
-        data=[{
-            "id": str(item.id),
-            "name": item.name,
-            "description": item.description,
-            "item_type": item.item_type,
-            "price_gems": item.price_gems,
-            "is_available": item.is_available,
-            "stock_quantity": item.stock_quantity
-        } for item in items]
-    )
-
-
-@router.post("/shop", response_model=ApiResponse[dict])
-async def create_shop_item(
-    name: str,
-    description: str,
-    item_type: str,
-    price_gems: int,
-    is_available: bool = True,
-    stock_quantity: Optional[int] = None,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Create a new shop item.
-    
-    Admin only endpoint.
-    """
-    item = ShopItem(
-        name=name,
-        description=description,
-        item_type=item_type,
-        price_gems=price_gems,
-        is_available=is_available,
-        stock_quantity=stock_quantity
-    )
-    db.add(item)
-    await db.commit()
-    await db.refresh(item)
-    
-    return ApiResponse(
-        success=True,
-        message="Shop item created successfully",
-        data={
-            "id": str(item.id),
-            "name": item.name,
-            "price_gems": item.price_gems
-        }
-    )
-
-
-@router.put("/shop/{item_id}", response_model=ApiResponse[dict])
-async def update_shop_item(
-    item_id: UUID,
-    name: Optional[str] = None,
-    description: Optional[str] = None,
-    price_gems: Optional[int] = None,
-    is_available: Optional[bool] = None,
-    stock_quantity: Optional[int] = None,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Update a shop item.
-    
-    Admin only endpoint.
-    """
-    result = await db.execute(
-        select(ShopItem).where(ShopItem.id == item_id)
-    )
-    item = result.scalar_one_or_none()
-    
-    if not item:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Shop item not found"
-        )
-    
-    if name is not None:
-        item.name = name
-    if description is not None:
-        item.description = description
-    if price_gems is not None:
-        item.price_gems = price_gems
-    if is_available is not None:
-        item.is_available = is_available
-    if stock_quantity is not None:
-        item.stock_quantity = stock_quantity
-    
-    await db.commit()
-    await db.refresh(item)
-    
-    return ApiResponse(
-        success=True,
-        message="Shop item updated successfully",
-        data={
-            "id": str(item.id),
-            "name": item.name,
-            "price_gems": item.price_gems,
-            "is_available": item.is_available
-        }
-    )
-
-
-@router.delete("/shop/{item_id}", response_model=ApiResponse[dict])
-async def delete_shop_item(
-    item_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Delete a shop item.
-    
-    Admin only endpoint.
-    """
-    result = await db.execute(
-        select(ShopItem).where(ShopItem.id == item_id)
-    )
-    item = result.scalar_one_or_none()
-    
-    if not item:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail="Shop item not found"
-        )
-    
-    await db.delete(item)
-    await db.commit()
-    
-    return ApiResponse(
-        success=True,
-        message="Shop item deleted successfully",
-        data={"deleted": True, "item_id": str(item_id)}
-    )
-
-
-# ============================================================================
-# Grammar Admin CRUD
-# ============================================================================
-
-@router.get("/grammar", response_model=ApiResponse[List[GrammarResponse]])
-async def list_grammar_admin(
-    limit: int = Query(50, ge=1, le=200),
-    offset: int = Query(0, ge=0),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(
-        select(GrammarItem).order_by(GrammarItem.created_at.desc()).limit(limit).offset(offset)
-    )
-    items = result.scalars().all()
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(items)} grammar items",
-        data=[GrammarResponse.model_validate(item) for item in items]
-    )
-
-
-@router.post("/grammar", response_model=ApiResponse[GrammarResponse])
-async def create_grammar_admin(
-    payload: GrammarCreate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    item = GrammarItem(
-        title=payload.title,
-        level=payload.level,
-        topic=payload.topic,
-        summary=payload.summary,
-        content=payload.content,
-        examples=payload.examples,
-        tags=payload.tags,
-        is_active=payload.is_active,
-    )
-    db.add(item)
-    await db.commit()
-    await db.refresh(item)
-    return ApiResponse(success=True, message="Grammar created", data=GrammarResponse.model_validate(item))
-
-
-@router.put("/grammar/{grammar_id}", response_model=ApiResponse[GrammarResponse])
-async def update_grammar_admin(
-    grammar_id: UUID,
-    payload: GrammarUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(select(GrammarItem).where(GrammarItem.id == grammar_id))
-    item = result.scalar_one_or_none()
-    if not item:
-        raise HTTPException(status_code=404, detail="Grammar item not found")
-
-    for field, value in payload.model_dump(exclude_unset=True).items():
-        setattr(item, field, value)
-
-    await db.commit()
-    await db.refresh(item)
-    return ApiResponse(success=True, message="Grammar updated", data=GrammarResponse.model_validate(item))
-
-
-@router.delete("/grammar/{grammar_id}", response_model=ApiResponse[dict])
-async def delete_grammar_admin(
-    grammar_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(select(GrammarItem).where(GrammarItem.id == grammar_id))
-    item = result.scalar_one_or_none()
-    if not item:
-        raise HTTPException(status_code=404, detail="Grammar item not found")
-    await db.delete(item)
-    await db.commit()
-    return ApiResponse(success=True, message="Grammar deleted", data={"deleted": True, "grammar_id": str(grammar_id)})
-
-
-# ============================================================================
-# Question Bank Admin CRUD
-# ============================================================================
-
-@router.get("/questions", response_model=ApiResponse[List[QuestionResponse]])
-async def list_questions_admin(
-    limit: int = Query(50, ge=1, le=200),
-    offset: int = Query(0, ge=0),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(
-        select(QuestionItem).order_by(QuestionItem.created_at.desc()).limit(limit).offset(offset)
-    )
-    items = result.scalars().all()
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(items)} questions",
-        data=[QuestionResponse.model_validate(item) for item in items]
-    )
-
-
-@router.post("/questions", response_model=ApiResponse[QuestionResponse])
-async def create_question_admin(
-    payload: QuestionCreate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    item = QuestionItem(
-        prompt=payload.prompt,
-        question_type=payload.question_type,
-        options=payload.options,
-        answer=payload.answer,
-        explanation=payload.explanation,
-        difficulty_level=payload.difficulty_level,
-        tags=payload.tags,
-        grammar_id=payload.grammar_id,
-        is_active=payload.is_active,
-    )
-    db.add(item)
-    await db.commit()
-    await db.refresh(item)
-    return ApiResponse(success=True, message="Question created", data=QuestionResponse.model_validate(item))
-
-
-@router.put("/questions/{question_id}", response_model=ApiResponse[QuestionResponse])
-async def update_question_admin(
-    question_id: UUID,
-    payload: QuestionUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(select(QuestionItem).where(QuestionItem.id == question_id))
-    item = result.scalar_one_or_none()
-    if not item:
-        raise HTTPException(status_code=404, detail="Question not found")
-
-    for field, value in payload.model_dump(exclude_unset=True).items():
-        setattr(item, field, value)
-
-    await db.commit()
-    await db.refresh(item)
-    return ApiResponse(success=True, message="Question updated", data=QuestionResponse.model_validate(item))
-
-
-@router.delete("/questions/{question_id}", response_model=ApiResponse[dict])
-async def delete_question_admin(
-    question_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(select(QuestionItem).where(QuestionItem.id == question_id))
-    item = result.scalar_one_or_none()
-    if not item:
-        raise HTTPException(status_code=404, detail="Question not found")
-    await db.delete(item)
-    await db.commit()
-    return ApiResponse(success=True, message="Question deleted", data={"deleted": True, "question_id": str(question_id)})
-
-
-# ============================================================================
-# Test Exam Admin CRUD
-# ============================================================================
-
-@router.get("/test-exams", response_model=ApiResponse[List[TestExamResponse]])
-async def list_test_exams_admin(
-    limit: int = Query(50, ge=1, le=200),
-    offset: int = Query(0, ge=0),
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(
-        select(TestExam).order_by(TestExam.created_at.desc()).limit(limit).offset(offset)
-    )
-    items = result.scalars().all()
-    return ApiResponse(
-        success=True,
-        message=f"Retrieved {len(items)} test exams",
-        data=[TestExamResponse.model_validate(item) for item in items]
-    )
-
-
-@router.post("/test-exams", response_model=ApiResponse[TestExamResponse])
-async def create_test_exam_admin(
-    payload: TestExamCreate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    item = TestExam(
-        title=payload.title,
-        description=payload.description,
-        level=payload.level,
-        duration_minutes=payload.duration_minutes,
-        passing_score=payload.passing_score,
-        question_ids=[str(q) for q in payload.question_ids] if payload.question_ids else None,
-        is_published=payload.is_published,
-    )
-    db.add(item)
-    await db.commit()
-    await db.refresh(item)
-    return ApiResponse(success=True, message="Test exam created", data=TestExamResponse.model_validate(item))
-
-
-@router.put("/test-exams/{test_exam_id}", response_model=ApiResponse[TestExamResponse])
-async def update_test_exam_admin(
-    test_exam_id: UUID,
-    payload: TestExamUpdate,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(select(TestExam).where(TestExam.id == test_exam_id))
-    item = result.scalar_one_or_none()
-    if not item:
-        raise HTTPException(status_code=404, detail="Test exam not found")
-
-    update_data = payload.model_dump(exclude_unset=True)
-    if "question_ids" in update_data and update_data["question_ids"] is not None:
-        update_data["question_ids"] = [str(q) for q in update_data["question_ids"]]
-    for field, value in update_data.items():
-        setattr(item, field, value)
-
-    await db.commit()
-    await db.refresh(item)
-    return ApiResponse(success=True, message="Test exam updated", data=TestExamResponse.model_validate(item))
-
-
-@router.delete("/test-exams/{test_exam_id}", response_model=ApiResponse[dict])
-async def delete_test_exam_admin(
-    test_exam_id: UUID,
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    result = await db.execute(select(TestExam).where(TestExam.id == test_exam_id))
-    item = result.scalar_one_or_none()
-    if not item:
-        raise HTTPException(status_code=404, detail="Test exam not found")
-    await db.delete(item)
-    await db.commit()
-    return ApiResponse(success=True, message="Test exam deleted", data={"deleted": True, "test_exam_id": str(test_exam_id)})
-
-
-# ============================================================================
-# Seed Data Endpoint (Development Only)
-# ============================================================================
-
-@router.post("/seed", response_model=ApiResponse[dict])
-async def seed_sample_data(
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """
-    Seed sample data for development/testing.
-    
-    Creates sample achievements, shop items, course categories, and courses.
-    Admin only endpoint.
-    """
-    created = {
-        "achievements": 0,
-        "shop_items": 0,
-        "course_categories": 0,
-        "courses": 0,
-        "units": 0,
-        "lessons": 0,
-    }
-    
-    # Sample Achievements
-    sample_achievements = [
-        {"name": "First Steps", "description": "Complete your first lesson", 
-         "condition_type": "lessons_completed", "condition_value": 1, 
-         "category": "lessons", "rarity": "common", "xp_reward": 10, "gems_reward": 5},
-        {"name": "Week Warrior", "description": "Maintain a 7-day streak", 
-         "condition_type": "streak_days", "condition_value": 7, 
-         "category": "streak", "rarity": "rare", "xp_reward": 50, "gems_reward": 20},
-        {"name": "Word Collector", "description": "Add 100 words to vocabulary", 
-         "condition_type": "vocab_count", "condition_value": 100, 
-         "category": "vocabulary", "rarity": "epic", "xp_reward": 100, "gems_reward": 50},
-        {"name": "Social Butterfly", "description": "Follow 10 friends", 
-         "condition_type": "following_count", "condition_value": 10, 
-         "category": "social", "rarity": "rare", "xp_reward": 30, "gems_reward": 15},
-    ]
-    
-    for ach_data in sample_achievements:
-        # Check if exists
-        result = await db.execute(
-            select(Achievement).where(Achievement.name == ach_data["name"])
-        )
-        if not result.scalar_one_or_none():
-            achievement = Achievement(**ach_data)
-            db.add(achievement)
-            created["achievements"] += 1
-    
-    # Sample Shop Items
-    from app.core.shop_catalog import SHOP_CATALOG
-    sample_shop_items = SHOP_CATALOG
-    
-    for item_data in sample_shop_items:
-        # Check if exists
-        result = await db.execute(
-            select(ShopItem).where(ShopItem.name == item_data["name"])
-        )
-        existing_item = result.scalar_one_or_none()
-        if not existing_item:
-            item = ShopItem(**item_data)
-            db.add(item)
-            created["shop_items"] += 1
-        else:
-            for field, value in item_data.items():
-                setattr(existing_item, field, value)
-
-    # Sample Course Categories
-    sample_categories = [
-        {
-            "name": "Grammar",
-            "slug": "grammar",
-            "description": "Master English grammar rules and structures",
-            "icon": "📚",
-            "color": "#4CAF50",
-            "order_index": 1,
-        },
-        {
-            "name": "Vocabulary",
-            "slug": "vocabulary",
-            "description": "Build practical English vocabulary for daily use",
-            "icon": "🧠",
-            "color": "#2196F3",
-            "order_index": 2,
-        },
-    ]
-
-    category_ids: dict[str, UUID] = {}
-    for category_data in sample_categories:
-        result = await db.execute(
-            select(CourseCategory).where(CourseCategory.slug == category_data["slug"])
-        )
-        category = result.scalar_one_or_none()
-        if not category:
-            category = CourseCategory(**category_data)
-            db.add(category)
-            await db.flush()
-            created["course_categories"] += 1
-        category_ids[category_data["slug"]] = category.id
-
-    # Sample published courses with basic roadmap content
-    sample_courses = [
-        {
-            "title": "English Grammar Foundations",
-            "description": "Start with core grammar patterns for everyday communication.",
-            "language": "en",
-            "level": "A1",
-            "category_slug": "grammar",
-            "tags": ["grammar", "beginner", "fundamentals"],
-            "total_xp": 120,
-            "estimated_duration": 90,
-            "thumbnail_url": "https://images.unsplash.com/photo-1456513080510-7bf3a84b82f8",
-            "units": [
-                {
-                    "title": "Present Simple Basics",
-                    "description": "Build confidence with daily routine sentences.",
-                    "order_index": 1,
-                    "background_color": "#1E3A8A",
-                    "lessons": [
-                        {
-                            "title": "I/You/We/They + Verb",
-                            "description": "Form positive present simple sentences.",
-                            "order_index": 1,
-                            "estimated_minutes": 12,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_g1_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "Choose the correct form: 'I ___ coffee every morning.'",
-                                    "options": [{"id": "0", "text": "drink", "is_correct": True}, {"id": "1", "text": "drinks", "is_correct": False}, {"id": "2", "text": "drinking", "is_correct": False}, {"id": "3", "text": "drunk", "is_correct": False}],
-                                    "correct_answer": "drink",
-                                    "explanation": "With I/You/We/They, use the base verb form."
-                                },
-                                {
-                                    "id": "ex_g1_2",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: 'They plays football' is grammatically correct.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": False}, {"id": "1", "text": "False", "is_correct": True}],
-                                    "correct_answer": "False",
-                                    "explanation": "'They' is plural and takes the base verb 'play', not 'plays'."
-                                },
-                                {
-                                    "id": "ex_g1_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete the sentence: 'We {blank} in a big city.'",
-                                    "correct_answer": "live",
-                                    "explanation": "'We' takes the base verb 'live'."
-                                },
-                                {
-                                    "id": "ex_g1_4",
-                                    "type": "reorder",
-                                    "ui_type": "arrange_the_sentence",
-                                    "question": "Arrange: 'day / every / study / they'",
-                                    "options": [{"id": "0", "text": "they"}, {"id": "1", "text": "study"}, {"id": "2", "text": "every"}, {"id": "3", "text": "day"}],
-                                    "correct_answer": "they study every day",
-                                    "explanation": "Subject + Verb + Time expression is the standard structure."
-                                },
-                                {
-                                    "id": "ex_g1_5",
-                                    "type": "translate",
-                                    "ui_type": "translation_choice",
-                                    "question": "Choose the translation for: 'Chúng tôi muốn học.'",
-                                    "options": [{"id": "0", "text": "We want to learn.", "is_correct": True}, {"id": "1", "text": "We wants to learn.", "is_correct": False}, {"id": "2", "text": "We learning.", "is_correct": False}],
-                                    "correct_answer": "We want to learn.",
-                                    "explanation": "'Chúng tôi' translates to 'We', which takes the base verb 'want'."
-                                },
-                                {
-                                    "id": "ex_g1_6",
-                                    "type": "fill_blank",
-                                    "ui_type": "dialogue_completion",
-                                    "question": "A: Do you speak English? B: Yes, I {blank}.",
-                                    "correct_answer": "do",
-                                    "explanation": "Short answer to 'Do you...' is 'I do'."
-                                },
-                                {
-                                    "id": "ex_g1_7",
-                                    "type": "multiple_choice",
-                                    "ui_type": "collocation_choice",
-                                    "question": "Complete the phrase: 'They ___ homework together.'",
-                                    "options": [{"id": "0", "text": "do", "is_correct": True}, {"id": "1", "text": "make", "is_correct": False}],
-                                    "correct_answer": "do",
-                                    "explanation": "The collocation is 'do homework'."
-                                },
-                                {
-                                    "id": "ex_g1_8",
-                                    "type": "fill_blank",
-                                    "ui_type": "dictation",
-                                    "question": "Listen and write what you hear: '{blank}'",
-                                    "correct_answer": "We go home",
-                                    "explanation": "Type the exact words heard in the audio."
-                                },
-                                {
-                                    "id": "ex_g1_9",
-                                    "type": "translate",
-                                    "ui_type": "speaking_repeat",
-                                    "question": "Repeat: 'I listen to music.'",
-                                    "correct_answer": "I listen to music",
-                                    "explanation": "Record yourself repeating this sentence."
-                                },
-                                {
-                                    "id": "ex_g1_10",
-                                    "type": "multiple_choice",
-                                    "ui_type": "vocabulary_flashcard",
-                                    "question": "Learn the card: 'Routine'",
-                                    "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
-                                    "correct_answer": "Got it!",
-                                    "explanation": "Routine is a sequence of actions regularly followed."
-                                }
-                            ]
-                        },
-                        {
-                            "title": "He/She/It + Verb-s",
-                            "description": "Use third-person singular correctly.",
-                            "order_index": 2,
-                            "estimated_minutes": 12,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_g2_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "Choose correct: 'He ___ to school by bus.'",
-                                    "options": [{"id": "0", "text": "go", "is_correct": False}, {"id": "1", "text": "goes", "is_correct": True}, {"id": "2", "text": "going", "is_correct": False}],
-                                    "correct_answer": "goes",
-                                    "explanation": "He/she/it takes verb+s/es."
-                                },
-                                {
-                                    "id": "ex_g2_2",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: 'It rain a lot' is correct.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": False}, {"id": "1", "text": "False", "is_correct": True}],
-                                    "correct_answer": "False",
-                                    "explanation": "It should be 'It rains a lot'."
-                                },
-                                {
-                                    "id": "ex_g2_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete: 'She {blank} the piano well.'",
-                                    "correct_answer": "plays",
-                                    "explanation": "She requires plays."
-                                },
-                                {
-                                    "id": "ex_g2_4",
-                                    "type": "fill_blank",
-                                    "ui_type": "grammar_correction",
-                                    "question": "Correct the error: 'He play tennis.' -> '{blank}'",
-                                    "correct_answer": "He plays tennis",
-                                    "explanation": "Add 's' to play."
-                                },
-                                {
-                                    "id": "ex_g2_5",
-                                    "type": "multiple_choice",
-                                    "ui_type": "image_based_choice",
-                                    "question": "Choose the image that represents: 'She runs.'",
-                                    "options": [{"id": "0", "text": "Running", "is_correct": True}, {"id": "1", "text": "Sleeping", "is_correct": False}],
-                                    "correct_answer": "Running",
-                                    "explanation": "Select the correct action card."
-                                },
-                                {
-                                    "id": "ex_g2_6",
-                                    "type": "multiple_choice",
-                                    "ui_type": "listen_and_choose",
-                                    "question": "Listen and select what he does.",
-                                    "options": [{"id": "0", "text": "He eats breakfast", "is_correct": True}, {"id": "1", "text": "He plays games", "is_correct": False}],
-                                    "correct_answer": "He eats breakfast",
-                                    "explanation": "Audio matches breakfast."
-                                },
-                                {
-                                    "id": "ex_g2_7",
-                                    "type": "translate",
-                                    "ui_type": "pronunciation_practice",
-                                    "question": "Practice speaking: 'He plays tennis.'",
-                                    "correct_answer": "He plays tennis",
-                                    "explanation": "Evaluate pronunciation of He plays tennis."
-                                },
-                                {
-                                    "id": "ex_g2_8",
-                                    "type": "multiple_choice",
-                                    "ui_type": "reading_comprehension",
-                                    "question": "Read and answer: 'Tom is a chef. He works in a restaurant.' Where does Tom work?",
-                                    "options": [{"id": "0", "text": "restaurant", "is_correct": True}, {"id": "1", "text": "office", "is_correct": False}],
-                                    "correct_answer": "restaurant",
-                                    "explanation": "The text states he works in a restaurant."
-                                },
-                                {
-                                    "id": "ex_g2_9",
-                                    "type": "fill_blank",
-                                    "ui_type": "short_writing_answer",
-                                    "question": "Write in English: 'Cô ấy nói tiếng Anh.'",
-                                    "correct_answer": "She speaks English",
-                                    "explanation": "Translate exactly."
-                                },
-                                {
-                                    "id": "ex_g2_10",
-                                    "type": "matching",
-                                    "ui_type": "categorization",
-                                    "question": "Categorize the pronouns: Singular vs Plural",
-                                    "options": [{"id": "he", "text": "Singular"}, {"id": "they", "text": "Plural"}],
-                                    "correct_answer": "he:Singular, they:Plural",
-                                    "explanation": "He is singular, they is plural."
-                                }
-                            ]
-                        },
-                    ],
-                },
-            ],
-        },
-        {
-            "title": "Daily Vocabulary Starter",
-            "description": "Learn essential words and phrases for daily life.",
-            "language": "en",
-            "level": "A1",
-            "category_slug": "vocabulary",
-            "tags": ["vocabulary", "daily-life", "beginner"],
-            "total_xp": 120,
-            "estimated_duration": 80,
-            "thumbnail_url": "https://images.unsplash.com/photo-1434030216411-0b793f4b4173",
-            "units": [
-                {
-                    "title": "Home and Family",
-                    "description": "Words you use every day at home.",
-                    "order_index": 1,
-                    "background_color": "#0F766E",
-                    "lessons": [
-                        {
-                            "title": "Family Members",
-                            "description": "Describe people in your family.",
-                            "order_index": 1,
-                            "estimated_minutes": 10,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_v1_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "Your father's sister is your ___.",
-                                    "options": [{"id": "0", "text": "aunt", "is_correct": True}, {"id": "1", "text": "uncle", "is_correct": False}],
-                                    "correct_answer": "aunt",
-                                    "explanation": "Father's sister is aunt."
-                                },
-                                {
-                                    "id": "ex_v1_2",
-                                    "type": "matching",
-                                    "ui_type": "match_word_to_meaning",
-                                    "question": "Match the family words with meanings.",
-                                    "options": [{"id": "father", "text": "Male parent"}, {"id": "mother", "text": "Female parent"}],
-                                    "correct_answer": "father:Male parent, mother:Female parent",
-                                    "explanation": "Father is male parent, mother is female."
-                                },
-                                {
-                                    "id": "ex_v1_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete: 'My mother's husband is my {blank}.'",
-                                    "correct_answer": "father",
-                                    "explanation": "Mother's husband is father."
-                                },
-                                {
-                                    "id": "ex_v1_4",
-                                    "type": "matching",
-                                    "ui_type": "cognitive_fluidity",
-                                    "question": "Match: mother, sister",
-                                    "options": [{"id": "mother", "text": "female parent"}, {"id": "sister", "text": "female sibling"}],
-                                    "correct_answer": "mother:female parent, sister:female sibling",
-                                    "explanation": "Fast match."
-                                },
-                                {
-                                    "id": "ex_v1_5",
-                                    "type": "multiple_choice",
-                                    "ui_type": "vocabulary_flashcard",
-                                    "question": "Learn: 'Sibling' (anh chị em ruột)",
-                                    "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
-                                    "correct_answer": "Got it!",
-                                    "explanation": "A sibling is a brother or sister."
-                                },
-                                {
-                                    "id": "ex_v1_6",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: 'Cousin' is the child of your aunt or uncle.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": True}, {"id": "1", "text": "False", "is_correct": False}],
-                                    "correct_answer": "True",
-                                    "explanation": "Cousin is child of aunt/uncle."
-                                },
-                                {
-                                    "id": "ex_v1_7",
-                                    "type": "reorder",
-                                    "ui_type": "arrange_the_sentence",
-                                    "question": "Arrange: 'my / this / is / brother'",
-                                    "options": [{"id": "0", "text": "this"}, {"id": "1", "text": "is"}, {"id": "2", "text": "my"}, {"id": "3", "text": "brother"}],
-                                    "correct_answer": "this is my brother",
-                                    "explanation": "Sentence structure."
-                                },
-                                {
-                                    "id": "ex_v1_8",
-                                    "type": "translate",
-                                    "ui_type": "translation_choice",
-                                    "question": "Translation of: 'Anh trai'",
-                                    "options": [{"id": "0", "text": "brother", "is_correct": True}, {"id": "1", "text": "sister", "is_correct": False}],
-                                    "correct_answer": "brother",
-                                    "explanation": "Anh trai is brother."
-                                },
-                                {
-                                    "id": "ex_v1_9",
-                                    "type": "translate",
-                                    "ui_type": "speaking_repeat",
-                                    "question": "Repeat: 'My grandmother is nice.'",
-                                    "correct_answer": "My grandmother is nice",
-                                    "explanation": "Practice speaking."
-                                },
-                                {
-                                    "id": "ex_v1_10",
-                                    "type": "fill_blank",
-                                    "ui_type": "dictation",
-                                    "question": "Dictation: Listen and write '{blank}'",
-                                    "correct_answer": "He is my uncle",
-                                    "explanation": "Type what you hear."
-                                }
-                            ]
-                        },
-                        {
-                            "title": "Rooms and Objects",
-                            "description": "Talk about places and things at home.",
-                            "order_index": 2,
-                            "estimated_minutes": 10,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_v2_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "You cook meals in the ___.",
-                                    "options": [{"id": "0", "text": "kitchen", "is_correct": True}, {"id": "1", "text": "bedroom", "is_correct": False}],
-                                    "correct_answer": "kitchen",
-                                    "explanation": "Kitchen is for cooking."
-                                },
-                                {
-                                    "id": "ex_v2_2",
-                                    "type": "matching",
-                                    "ui_type": "match_word_to_meaning",
-                                    "question": "Match rooms with objects.",
-                                    "options": [{"id": "bedroom", "text": "bed"}, {"id": "kitchen", "text": "fridge"}],
-                                    "correct_answer": "bedroom:bed, kitchen:fridge",
-                                    "explanation": "Bed in bedroom, fridge in kitchen."
-                                },
-                                {
-                                    "id": "ex_v2_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete: 'I sleep in my {blank}.'",
-                                    "correct_answer": "bedroom",
-                                    "explanation": "Bedroom is for sleeping."
-                                },
-                                {
-                                    "id": "ex_v2_4",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: A sofa is typically placed in the living room.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": True}, {"id": "1", "text": "False", "is_correct": False}],
-                                    "correct_answer": "True",
-                                    "explanation": "Sofa in living room."
-                                },
-                                {
-                                    "id": "ex_v2_5",
-                                    "type": "reorder",
-                                    "ui_type": "arrange_the_sentence",
-                                    "question": "Arrange: 'in / the / bed / is / bedroom / the'",
-                                    "options": [{"id": "0", "text": "the"}, {"id": "1", "text": "bed"}, {"id": "2", "text": "is"}, {"id": "3", "text": "in"}, {"id": "4", "text": "the"}, {"id": "5", "text": "bedroom"}],
-                                    "correct_answer": "the bed is in the bedroom",
-                                    "explanation": "Correct sentence structure."
-                                },
-                                {
-                                    "id": "ex_v2_6",
-                                    "type": "translate",
-                                    "ui_type": "translation_choice",
-                                    "question": "Translation of: 'Phòng tắm'",
-                                    "options": [{"id": "0", "text": "bathroom", "is_correct": True}, {"id": "1", "text": "garden", "is_correct": False}],
-                                    "correct_answer": "bathroom",
-                                    "explanation": "Phòng tắm is bathroom."
-                                },
-                                {
-                                    "id": "ex_v2_7",
-                                    "type": "translate",
-                                    "ui_type": "speaking_repeat",
-                                    "question": "Repeat: 'The desk is clean.'",
-                                    "correct_answer": "The desk is clean",
-                                    "explanation": "Evaluate pronunciation."
-                                },
-                                {
-                                    "id": "ex_v2_8",
-                                    "type": "fill_blank",
-                                    "ui_type": "dictation",
-                                    "question": "Dictation: Listen and write '{blank}'",
-                                    "correct_answer": "Open the window",
-                                    "explanation": "Write what you hear."
-                                },
-                                {
-                                    "id": "ex_v2_9",
-                                    "type": "multiple_choice",
-                                    "ui_type": "image_based_choice",
-                                    "question": "Select the image that shows a table.",
-                                    "options": [{"id": "0", "text": "Table", "is_correct": True}, {"id": "1", "text": "Chair", "is_correct": False}],
-                                    "correct_answer": "Table",
-                                    "explanation": "Card with table."
-                                },
-                                {
-                                    "id": "ex_v2_10",
-                                    "type": "multiple_choice",
-                                    "ui_type": "vocabulary_flashcard",
-                                    "question": "Learn: 'Furnishings'",
-                                    "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
-                                    "correct_answer": "Got it!",
-                                    "explanation": "Furniture and appliances in a room."
-                                }
-                            ]
-                        },
-                    ],
-                },
-            ],
-        },
-    ]
-
-    for course_data in sample_courses:
-        result = await db.execute(
-            select(Course).where(Course.title == course_data["title"])
-        )
-        existing_course = result.scalar_one_or_none()
-        if existing_course:
-            await db.delete(existing_course)
-            await db.flush()
-
-        unit_seed = course_data.pop("units")
-        category_slug = course_data.pop("category_slug")
-
-        course = Course(
-            **course_data,
-            category_id=category_ids.get(category_slug),
-            total_lessons=sum(len(unit["lessons"]) for unit in unit_seed),
-            is_published=True,
-        )
-        db.add(course)
-        await db.flush()
-        created["courses"] += 1
-
-        for unit_data in unit_seed:
-            lesson_seed = unit_data.pop("lessons")
-            unit = Unit(
-                **unit_data,
-                course_id=course.id,
-                total_lessons=len(lesson_seed),
-            )
-            db.add(unit)
-            await db.flush()
-            created["units"] += 1
-
-            for lesson_data in lesson_seed:
-                exercises = lesson_data.pop("exercises", [])
-                lesson = Lesson(
-                    **lesson_data,
-                    course_id=course.id,
-                    unit_id=unit.id,
-                    content={"exercises": exercises, "version": 1},
-                    pass_threshold=70,
-                    lesson_type="lesson",
-                )
-                db.add(lesson)
-                created["lessons"] += 1
-    
-    await db.commit()
-    
-    return ApiResponse(
-        success=True,
-        message=(
-            "Seed data created: "
-            f"{created['achievements']} achievements, "
-            f"{created['shop_items']} shop items, "
-            f"{created['course_categories']} categories, "
-            f"{created['courses']} courses, "
-            f"{created['units']} units, "
-            f"{created['lessons']} lessons"
-        ),
-        data=created
-    )
-
-
-# ============================================================================
-# System Settings / Info
-# ============================================================================
-
-@router.get("/system-info", response_model=ApiResponse[dict])
-async def get_system_info(
-    db: AsyncSession = Depends(get_db),
-    admin_user: User = Depends(require_admin)
-):
-    """Get system configuration and stats. Admin only."""
-    from app.core.config import settings as app_settings
-    from app.models.user import User as UserModel
-
-    # Count totals
-    user_count = (await db.execute(select(func.count(UserModel.id)))).scalar() or 0
-    course_count = (await db.execute(select(func.count(Course.id)))).scalar() or 0
-    vocab_count = (await db.execute(select(func.count(VocabularyItem.id)))).scalar() or 0
-    achievement_count = (await db.execute(select(func.count(Achievement.id)))).scalar() or 0
-
-    return ApiResponse(
-        success=True,
-        message="System info",
-        data={
-            "app_name": app_settings.APP_NAME,
-            "app_env": app_settings.APP_ENV,
-            "debug": app_settings.DEBUG,
-            "api_prefix": app_settings.API_V1_PREFIX,
-            "log_level": app_settings.LOG_LEVEL,
-            "token_expire_minutes": app_settings.ACCESS_TOKEN_EXPIRE_MINUTES,
-            "refresh_token_days": app_settings.REFRESH_TOKEN_EXPIRE_DAYS,
-            "cors_origins": app_settings.cors_origins,
-            "ai_service_url": app_settings.AI_SERVICE_URL,
-            "google_oauth": bool(app_settings.GOOGLE_CLIENT_ID),
-            "firebase": bool(app_settings.FIREBASE_PROJECT_ID),
-            "totals": {
-                "users": user_count,
-                "courses": course_count,
-                "vocabulary": vocab_count,
-                "achievements": achievement_count,
-            }
-        }
-    )
-
-
-from pydantic import BaseModel
-
-class SystemInfoUpdate(BaseModel):
-    app_name: Optional[str] = None
-    debug: Optional[bool] = None
-    log_level: Optional[str] = None
-    token_expire_minutes: Optional[int] = None
-    refresh_token_days: Optional[int] = None
-    cors_origins: Optional[str] = None
-    ai_service_url: Optional[str] = None
-
-@router.put("/system-info", response_model=ApiResponse[dict])
-async def update_system_info(
-    payload: SystemInfoUpdate,
-    admin_user: User = Depends(require_admin)
-):
-    """Update system configuration. Admin only."""
-    from app.core.config import settings as app_settings
-    from pathlib import Path
-
-    updates = {}
-    
-    if payload.app_name is not None:
-        app_settings.APP_NAME = payload.app_name
-        updates["APP_NAME"] = payload.app_name
-        
-    if payload.debug is not None:
-        app_settings.DEBUG = payload.debug
-        updates["DEBUG"] = payload.debug
-        
-    if payload.log_level is not None:
-        level = payload.log_level.upper()
-        if level in ["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]:
-            app_settings.LOG_LEVEL = level
-            updates["LOG_LEVEL"] = level
-            
-    if payload.token_expire_minutes is not None:
-        app_settings.ACCESS_TOKEN_EXPIRE_MINUTES = payload.token_expire_minutes
-        updates["ACCESS_TOKEN_EXPIRE_MINUTES"] = payload.token_expire_minutes
-        
-    if payload.refresh_token_days is not None:
-        app_settings.REFRESH_TOKEN_EXPIRE_DAYS = payload.refresh_token_days
-        updates["REFRESH_TOKEN_EXPIRE_DAYS"] = payload.refresh_token_days
-        
-    if payload.cors_origins is not None:
-        app_settings.ALLOWED_ORIGINS = payload.cors_origins
-        updates["ALLOWED_ORIGINS"] = payload.cors_origins
-        
-    if payload.ai_service_url is not None:
-        app_settings.AI_SERVICE_URL = payload.ai_service_url
-        updates["AI_SERVICE_URL"] = payload.ai_service_url
-
-    if updates:
-        project_root = Path(__file__).parent.parent.parent
-        env_file = project_root / ".env"
-        if app_settings.APP_ENV == "production":
-            prod_env = project_root / ".env.production"
-            if prod_env.exists():
-                env_file = prod_env
-        
-        try:
-            content = env_file.read_text() if env_file.exists() else ""
-            lines = content.splitlines()
-            new_lines = []
-            updated_keys = set()
-            
-            for line in lines:
-                stripped = line.strip()
-                if not stripped or stripped.startswith("#"):
-                    new_lines.append(line)
-                    continue
-                if "=" in stripped:
-                    key, val = stripped.split("=", 1)
-                    key = key.strip()
-                    if key in updates:
-                        new_val = updates[key]
-                        if isinstance(new_val, bool):
-                            new_val_str = "true" if new_val else "false"
-                        else:
-                            new_val_str = str(new_val)
-                        new_lines.append(f"{key}={new_val_str}")
-                        updated_keys.add(key)
-                    else:
-                        new_lines.append(line)
-                else:
-                    new_lines.append(line)
-                    
-            for key, val in updates.items():
-                if key not in updated_keys:
-                    if isinstance(val, bool):
-                        val_str = "true" if val else "false"
-                    else:
-                        val_str = str(val)
-                    new_lines.append(f"{key}={val_str}")
-                    
-            env_file.write_text("\n".join(new_lines) + "\n")
-        except Exception as e:
-            # Silently fallback if unable to write file in docker environment
-            pass
-
-    return ApiResponse(
-        success=True,
-        message="System configuration updated successfully",
-        data={
-            "app_name": app_settings.APP_NAME,
-            "app_env": app_settings.APP_ENV,
-            "debug": app_settings.DEBUG,
-            "api_prefix": app_settings.API_V1_PREFIX,
-            "log_level": app_settings.LOG_LEVEL,
-            "token_expire_minutes": app_settings.ACCESS_TOKEN_EXPIRE_MINUTES,
-            "refresh_token_days": app_settings.REFRESH_TOKEN_EXPIRE_DAYS,
-            "cors_origins": app_settings.cors_origins,
-            "ai_service_url": app_settings.AI_SERVICE_URL,
-        }
-    )
-
-
-# ============================================================================
-# User Admin (RBAC) - MOVED TO app/routes/user_management.py
-# ============================================================================
-# Legacy routes removed - use /api/v1/admin/users/* endpoints from user_management.py
-
-
-# ============================================================================
-# API Quota Monitoring (Phase 0 Infrastructure)
-# ============================================================================
-
-@router.get("/quota-usage", response_model=ApiResponse[dict])
-async def get_quota_usage(
-    api_name: Optional[str] = Query(None, description="Specific API to check"),
-    admin_user: User = Depends(require_admin),
-):
-    """
-    Get current API quota usage for all APIs or a specific one.
-    
-    Returns usage stats including threshold status, remaining budget,
-    and time until daily reset.
-    """
-    from app.services.quota_manager import QuotaManager
-
-    if api_name:
-        if api_name not in QuotaManager.LIMITS:
-            raise HTTPException(
-                status_code=status.HTTP_404_NOT_FOUND,
-                detail=f"Unknown API: {api_name}. "
-                       f"Available: {list(QuotaManager.LIMITS.keys())}",
-            )
-        usage = await QuotaManager.get_usage(api_name)
-        return ApiResponse(
-            success=True,
-            message=f"Quota usage for {api_name}",
-            data=usage,
-        )
-
-    all_usage = await QuotaManager.get_all_usage()
-    return ApiResponse(
-        success=True,
-        message=f"Quota usage for {len(all_usage)} APIs",
-        data={
-            "apis": all_usage,
-            "reset_in": QuotaManager.get_reset_time(),
-        },
-    )
-
-
-@router.post("/quota-reset/{api_name}", response_model=ApiResponse[dict])
-async def reset_quota(
-    api_name: str,
-    admin_user: User = Depends(require_admin),
-):
-    """
-    Manually reset quota counter for a specific API (emergency use).
-    
-    Use when: quota incorrectly tracked, or need to allow more requests
-    after investigating an issue.
-    """
-    from app.services.quota_manager import QuotaManager
-
-    if api_name not in QuotaManager.LIMITS:
-        raise HTTPException(
-            status_code=status.HTTP_404_NOT_FOUND,
-            detail=f"Unknown API: {api_name}. "
-                   f"Available: {list(QuotaManager.LIMITS.keys())}",
-        )
-
-    success = await QuotaManager.reset_quota(api_name)
-    if not success:
-        raise HTTPException(
-            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
-            detail="Redis unavailable, cannot reset quota.",
-        )
-
-    return ApiResponse(
-        success=True,
-        message=f"Quota reset for {api_name}",
-        data=await QuotaManager.get_usage(api_name),
-    )
diff --git a/backend-service/app/routes/admin_gamification.py b/backend-service/app/routes/admin_gamification.py
index 1757123c..3c707028 100644
--- a/backend-service/app/routes/admin_gamification.py
+++ b/backend-service/app/routes/admin_gamification.py
@@ -11,6 +11,7 @@
 from app.models.user import User
 from app.models.gamification import Achievement, ShopItem
 from app.schemas.response import ApiResponse
+from app.schemas.gamification import ShopItemAdminCreate, ShopItemAdminUpdate
 
 router = APIRouter(prefix="/admin", tags=["Admin"])
 
@@ -220,6 +221,8 @@ async def list_shop_items_admin(
             "description": item.description,
             "item_type": item.item_type,
             "price_gems": item.price_gems,
+            "icon_url": item.icon_url,
+            "effects": item.effects,
             "is_available": item.is_available,
             "stock_quantity": item.stock_quantity
         } for item in items]
@@ -228,32 +231,29 @@ async def list_shop_items_admin(
 
 @router.post("/shop", response_model=ApiResponse[dict])
 async def create_shop_item(
-    name: str,
-    description: str,
-    item_type: str,
-    price_gems: int,
-    is_available: bool = True,
-    stock_quantity: Optional[int] = None,
+    payload: ShopItemAdminCreate,
     db: AsyncSession = Depends(get_db),
     admin_user: User = Depends(require_admin)
 ):
     """
     Create a new shop item.
-    
+
     Admin only endpoint.
     """
     item = ShopItem(
-        name=name,
-        description=description,
-        item_type=item_type,
-        price_gems=price_gems,
-        is_available=is_available,
-        stock_quantity=stock_quantity
+        name=payload.name,
+        description=payload.description,
+        item_type=payload.item_type,
+        price_gems=payload.price_gems,
+        icon_url=payload.icon_url,
+        effects=payload.effects,
+        is_available=payload.is_available,
+        stock_quantity=payload.stock_quantity
     )
     db.add(item)
     await db.commit()
     await db.refresh(item)
-    
+
     return ApiResponse(
         success=True,
         message="Shop item created successfully",
@@ -268,44 +268,46 @@ async def create_shop_item(
 @router.put("/shop/{item_id}", response_model=ApiResponse[dict])
 async def update_shop_item(
     item_id: UUID,
-    name: Optional[str] = None,
-    description: Optional[str] = None,
-    price_gems: Optional[int] = None,
-    is_available: Optional[bool] = None,
-    stock_quantity: Optional[int] = None,
+    payload: ShopItemAdminUpdate,
     db: AsyncSession = Depends(get_db),
     admin_user: User = Depends(require_admin)
 ):
     """
     Update a shop item.
-    
+
     Admin only endpoint.
     """
     result = await db.execute(
         select(ShopItem).where(ShopItem.id == item_id)
     )
     item = result.scalar_one_or_none()
-    
+
     if not item:
         raise HTTPException(
             status_code=status.HTTP_404_NOT_FOUND,
             detail="Shop item not found"
         )
-    
-    if name is not None:
-        item.name = name
-    if description is not None:
-        item.description = description
-    if price_gems is not None:
-        item.price_gems = price_gems
-    if is_available is not None:
-        item.is_available = is_available
-    if stock_quantity is not None:
-        item.stock_quantity = stock_quantity
-    
+
+    if payload.name is not None:
+        item.name = payload.name
+    if payload.description is not None:
+        item.description = payload.description
+    if payload.item_type is not None:
+        item.item_type = payload.item_type
+    if payload.price_gems is not None:
+        item.price_gems = payload.price_gems
+    if payload.icon_url is not None:
+        item.icon_url = payload.icon_url
+    if payload.effects is not None:
+        item.effects = payload.effects
+    if payload.is_available is not None:
+        item.is_available = payload.is_available
+    if payload.stock_quantity is not None:
+        item.stock_quantity = payload.stock_quantity
+
     await db.commit()
     await db.refresh(item)
-    
+
     return ApiResponse(
         success=True,
         message="Shop item updated successfully",
diff --git a/backend-service/app/routes/admin_system.py b/backend-service/app/routes/admin_system.py
index 3ae4ef5c..ab07c36b 100644
--- a/backend-service/app/routes/admin_system.py
+++ b/backend-service/app/routes/admin_system.py
@@ -1,6 +1,5 @@
 """Admin routes — seed data, system info, and quota monitoring."""
 from typing import Optional, List
-from uuid import UUID
 
 from fastapi import APIRouter, Depends, HTTPException, Query, status
 from sqlalchemy import select, func
@@ -9,12 +8,11 @@
 from app.core.database import get_db
 from app.core.dependencies import get_current_admin, get_current_super_admin
 from app.models.user import User
-from app.models.course import Course, Unit, Lesson
-from app.models.course_category import CourseCategory
+from app.models.course import Course
 from app.models.vocabulary import VocabularyItem
-from app.models.gamification import Achievement, ShopItem
-from app.models.content import GrammarItem, QuestionItem, TestExam
+from app.models.gamification import Achievement
 from app.schemas.response import ApiResponse
+from app.services import admin_seed_service
 
 router = APIRouter(prefix="/admin", tags=["Admin"])
 
@@ -32,576 +30,28 @@ async def seed_sample_data(
 ):
     """
     Seed sample data for development/testing.
-    
+
     Creates sample achievements, shop items, course categories, and courses.
     Admin only endpoint.
     """
+    achievements_created = await admin_seed_service.seed_achievements(db)
+    shop_items_created = await admin_seed_service.seed_shop_items(db)
+    categories_created, category_ids = await admin_seed_service.seed_course_categories(db)
+    courses_created, units_created, lessons_created = await admin_seed_service.seed_courses(
+        db, category_ids
+    )
+
+    await db.commit()
+
     created = {
-        "achievements": 0,
-        "shop_items": 0,
-        "course_categories": 0,
-        "courses": 0,
-        "units": 0,
-        "lessons": 0,
+        "achievements": achievements_created,
+        "shop_items": shop_items_created,
+        "course_categories": categories_created,
+        "courses": courses_created,
+        "units": units_created,
+        "lessons": lessons_created,
     }
-    
-    # Sample Achievements
-    sample_achievements = [
-        {"name": "First Steps", "description": "Complete your first lesson", 
-         "condition_type": "lessons_completed", "condition_value": 1, 
-         "category": "lessons", "rarity": "common", "xp_reward": 10, "gems_reward": 5},
-        {"name": "Week Warrior", "description": "Maintain a 7-day streak", 
-         "condition_type": "streak_days", "condition_value": 7, 
-         "category": "streak", "rarity": "rare", "xp_reward": 50, "gems_reward": 20},
-        {"name": "Word Collector", "description": "Add 100 words to vocabulary", 
-         "condition_type": "vocab_count", "condition_value": 100, 
-         "category": "vocabulary", "rarity": "epic", "xp_reward": 100, "gems_reward": 50},
-        {"name": "Social Butterfly", "description": "Follow 10 friends", 
-         "condition_type": "following_count", "condition_value": 10, 
-         "category": "social", "rarity": "rare", "xp_reward": 30, "gems_reward": 15},
-    ]
-    
-    for ach_data in sample_achievements:
-        # Check if exists
-        result = await db.execute(
-            select(Achievement).where(Achievement.name == ach_data["name"])
-        )
-        if not result.scalar_one_or_none():
-            achievement = Achievement(**ach_data)
-            db.add(achievement)
-            created["achievements"] += 1
-    
-    # Sample Shop Items
-    from app.core.shop_catalog import SHOP_CATALOG
-    sample_shop_items = SHOP_CATALOG
-    
-    for item_data in sample_shop_items:
-        # Check if exists
-        result = await db.execute(
-            select(ShopItem).where(ShopItem.name == item_data["name"])
-        )
-        existing_item = result.scalar_one_or_none()
-        if not existing_item:
-            item = ShopItem(**item_data)
-            db.add(item)
-            created["shop_items"] += 1
-        else:
-            for field, value in item_data.items():
-                setattr(existing_item, field, value)
-
-    # Sample Course Categories
-    sample_categories = [
-        {
-            "name": "Grammar",
-            "slug": "grammar",
-            "description": "Master English grammar rules and structures",
-            "icon": "📚",
-            "color": "#4CAF50",
-            "order_index": 1,
-        },
-        {
-            "name": "Vocabulary",
-            "slug": "vocabulary",
-            "description": "Build practical English vocabulary for daily use",
-            "icon": "🧠",
-            "color": "#2196F3",
-            "order_index": 2,
-        },
-    ]
-
-    category_ids: dict[str, UUID] = {}
-    for category_data in sample_categories:
-        result = await db.execute(
-            select(CourseCategory).where(CourseCategory.slug == category_data["slug"])
-        )
-        category = result.scalar_one_or_none()
-        if not category:
-            category = CourseCategory(**category_data)
-            db.add(category)
-            await db.flush()
-            created["course_categories"] += 1
-        category_ids[category_data["slug"]] = category.id
-
-    # Sample published courses with basic roadmap content
-    sample_courses = [
-        {
-            "title": "English Grammar Foundations",
-            "description": "Start with core grammar patterns for everyday communication.",
-            "language": "en",
-            "level": "A1",
-            "category_slug": "grammar",
-            "tags": ["grammar", "beginner", "fundamentals"],
-            "total_xp": 120,
-            "estimated_duration": 90,
-            "thumbnail_url": "https://images.unsplash.com/photo-1456513080510-7bf3a84b82f8",
-            "units": [
-                {
-                    "title": "Present Simple Basics",
-                    "description": "Build confidence with daily routine sentences.",
-                    "order_index": 1,
-                    "background_color": "#1E3A8A",
-                    "lessons": [
-                        {
-                            "title": "I/You/We/They + Verb",
-                            "description": "Form positive present simple sentences.",
-                            "order_index": 1,
-                            "estimated_minutes": 12,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_g1_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "Choose the correct form: 'I ___ coffee every morning.'",
-                                    "options": [{"id": "0", "text": "drink", "is_correct": True}, {"id": "1", "text": "drinks", "is_correct": False}, {"id": "2", "text": "drinking", "is_correct": False}, {"id": "3", "text": "drunk", "is_correct": False}],
-                                    "correct_answer": "drink",
-                                    "explanation": "With I/You/We/They, use the base verb form."
-                                },
-                                {
-                                    "id": "ex_g1_2",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: 'They plays football' is grammatically correct.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": False}, {"id": "1", "text": "False", "is_correct": True}],
-                                    "correct_answer": "False",
-                                    "explanation": "'They' is plural and takes the base verb 'play', not 'plays'."
-                                },
-                                {
-                                    "id": "ex_g1_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete the sentence: 'We {blank} in a big city.'",
-                                    "correct_answer": "live",
-                                    "explanation": "'We' takes the base verb 'live'."
-                                },
-                                {
-                                    "id": "ex_g1_4",
-                                    "type": "reorder",
-                                    "ui_type": "arrange_the_sentence",
-                                    "question": "Arrange: 'day / every / study / they'",
-                                    "options": [{"id": "0", "text": "they"}, {"id": "1", "text": "study"}, {"id": "2", "text": "every"}, {"id": "3", "text": "day"}],
-                                    "correct_answer": "they study every day",
-                                    "explanation": "Subject + Verb + Time expression is the standard structure."
-                                },
-                                {
-                                    "id": "ex_g1_5",
-                                    "type": "translate",
-                                    "ui_type": "translation_choice",
-                                    "question": "Choose the translation for: 'Chúng tôi muốn học.'",
-                                    "options": [{"id": "0", "text": "We want to learn.", "is_correct": True}, {"id": "1", "text": "We wants to learn.", "is_correct": False}, {"id": "2", "text": "We learning.", "is_correct": False}],
-                                    "correct_answer": "We want to learn.",
-                                    "explanation": "'Chúng tôi' translates to 'We', which takes the base verb 'want'."
-                                },
-                                {
-                                    "id": "ex_g1_6",
-                                    "type": "fill_blank",
-                                    "ui_type": "dialogue_completion",
-                                    "question": "A: Do you speak English? B: Yes, I {blank}.",
-                                    "correct_answer": "do",
-                                    "explanation": "Short answer to 'Do you...' is 'I do'."
-                                },
-                                {
-                                    "id": "ex_g1_7",
-                                    "type": "multiple_choice",
-                                    "ui_type": "collocation_choice",
-                                    "question": "Complete the phrase: 'They ___ homework together.'",
-                                    "options": [{"id": "0", "text": "do", "is_correct": True}, {"id": "1", "text": "make", "is_correct": False}],
-                                    "correct_answer": "do",
-                                    "explanation": "The collocation is 'do homework'."
-                                },
-                                {
-                                    "id": "ex_g1_8",
-                                    "type": "fill_blank",
-                                    "ui_type": "dictation",
-                                    "question": "Listen and write what you hear: '{blank}'",
-                                    "correct_answer": "We go home",
-                                    "explanation": "Type the exact words heard in the audio."
-                                },
-                                {
-                                    "id": "ex_g1_9",
-                                    "type": "translate",
-                                    "ui_type": "speaking_repeat",
-                                    "question": "Repeat: 'I listen to music.'",
-                                    "correct_answer": "I listen to music",
-                                    "explanation": "Record yourself repeating this sentence."
-                                },
-                                {
-                                    "id": "ex_g1_10",
-                                    "type": "multiple_choice",
-                                    "ui_type": "vocabulary_flashcard",
-                                    "question": "Learn the card: 'Routine'",
-                                    "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
-                                    "correct_answer": "Got it!",
-                                    "explanation": "Routine is a sequence of actions regularly followed."
-                                }
-                            ]
-                        },
-                        {
-                            "title": "He/She/It + Verb-s",
-                            "description": "Use third-person singular correctly.",
-                            "order_index": 2,
-                            "estimated_minutes": 12,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_g2_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "Choose correct: 'He ___ to school by bus.'",
-                                    "options": [{"id": "0", "text": "go", "is_correct": False}, {"id": "1", "text": "goes", "is_correct": True}, {"id": "2", "text": "going", "is_correct": False}],
-                                    "correct_answer": "goes",
-                                    "explanation": "He/she/it takes verb+s/es."
-                                },
-                                {
-                                    "id": "ex_g2_2",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: 'It rain a lot' is correct.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": False}, {"id": "1", "text": "False", "is_correct": True}],
-                                    "correct_answer": "False",
-                                    "explanation": "It should be 'It rains a lot'."
-                                },
-                                {
-                                    "id": "ex_g2_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete: 'She {blank} the piano well.'",
-                                    "correct_answer": "plays",
-                                    "explanation": "She requires plays."
-                                },
-                                {
-                                    "id": "ex_g2_4",
-                                    "type": "fill_blank",
-                                    "ui_type": "grammar_correction",
-                                    "question": "Correct the error: 'He play tennis.' -> '{blank}'",
-                                    "correct_answer": "He plays tennis",
-                                    "explanation": "Add 's' to play."
-                                },
-                                {
-                                    "id": "ex_g2_5",
-                                    "type": "multiple_choice",
-                                    "ui_type": "image_based_choice",
-                                    "question": "Choose the image that represents: 'She runs.'",
-                                    "options": [{"id": "0", "text": "Running", "is_correct": True}, {"id": "1", "text": "Sleeping", "is_correct": False}],
-                                    "correct_answer": "Running",
-                                    "explanation": "Select the correct action card."
-                                },
-                                {
-                                    "id": "ex_g2_6",
-                                    "type": "multiple_choice",
-                                    "ui_type": "listen_and_choose",
-                                    "question": "Listen and select what he does.",
-                                    "options": [{"id": "0", "text": "He eats breakfast", "is_correct": True}, {"id": "1", "text": "He plays games", "is_correct": False}],
-                                    "correct_answer": "He eats breakfast",
-                                    "explanation": "Audio matches breakfast."
-                                },
-                                {
-                                    "id": "ex_g2_7",
-                                    "type": "translate",
-                                    "ui_type": "pronunciation_practice",
-                                    "question": "Practice speaking: 'He plays tennis.'",
-                                    "correct_answer": "He plays tennis",
-                                    "explanation": "Evaluate pronunciation of He plays tennis."
-                                },
-                                {
-                                    "id": "ex_g2_8",
-                                    "type": "multiple_choice",
-                                    "ui_type": "reading_comprehension",
-                                    "question": "Read and answer: 'Tom is a chef. He works in a restaurant.' Where does Tom work?",
-                                    "options": [{"id": "0", "text": "restaurant", "is_correct": True}, {"id": "1", "text": "office", "is_correct": False}],
-                                    "correct_answer": "restaurant",
-                                    "explanation": "The text states he works in a restaurant."
-                                },
-                                {
-                                    "id": "ex_g2_9",
-                                    "type": "fill_blank",
-                                    "ui_type": "short_writing_answer",
-                                    "question": "Write in English: 'Cô ấy nói tiếng Anh.'",
-                                    "correct_answer": "She speaks English",
-                                    "explanation": "Translate exactly."
-                                },
-                                {
-                                    "id": "ex_g2_10",
-                                    "type": "matching",
-                                    "ui_type": "categorization",
-                                    "question": "Categorize the pronouns: Singular vs Plural",
-                                    "options": [{"id": "he", "text": "Singular"}, {"id": "they", "text": "Plural"}],
-                                    "correct_answer": "he:Singular, they:Plural",
-                                    "explanation": "He is singular, they is plural."
-                                }
-                            ]
-                        },
-                    ],
-                },
-            ],
-        },
-        {
-            "title": "Daily Vocabulary Starter",
-            "description": "Learn essential words and phrases for daily life.",
-            "language": "en",
-            "level": "A1",
-            "category_slug": "vocabulary",
-            "tags": ["vocabulary", "daily-life", "beginner"],
-            "total_xp": 120,
-            "estimated_duration": 80,
-            "thumbnail_url": "https://images.unsplash.com/photo-1434030216411-0b793f4b4173",
-            "units": [
-                {
-                    "title": "Home and Family",
-                    "description": "Words you use every day at home.",
-                    "order_index": 1,
-                    "background_color": "#0F766E",
-                    "lessons": [
-                        {
-                            "title": "Family Members",
-                            "description": "Describe people in your family.",
-                            "order_index": 1,
-                            "estimated_minutes": 10,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_v1_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "Your father's sister is your ___.",
-                                    "options": [{"id": "0", "text": "aunt", "is_correct": True}, {"id": "1", "text": "uncle", "is_correct": False}],
-                                    "correct_answer": "aunt",
-                                    "explanation": "Father's sister is aunt."
-                                },
-                                {
-                                    "id": "ex_v1_2",
-                                    "type": "matching",
-                                    "ui_type": "match_word_to_meaning",
-                                    "question": "Match the family words with meanings.",
-                                    "options": [{"id": "father", "text": "Male parent"}, {"id": "mother", "text": "Female parent"}],
-                                    "correct_answer": "father:Male parent, mother:Female parent",
-                                    "explanation": "Father is male parent, mother is female."
-                                },
-                                {
-                                    "id": "ex_v1_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete: 'My mother's husband is my {blank}.'",
-                                    "correct_answer": "father",
-                                    "explanation": "Mother's husband is father."
-                                },
-                                {
-                                    "id": "ex_v1_4",
-                                    "type": "matching",
-                                    "ui_type": "cognitive_fluidity",
-                                    "question": "Match: mother, sister",
-                                    "options": [{"id": "mother", "text": "female parent"}, {"id": "sister", "text": "female sibling"}],
-                                    "correct_answer": "mother:female parent, sister:female sibling",
-                                    "explanation": "Fast match."
-                                },
-                                {
-                                    "id": "ex_v1_5",
-                                    "type": "multiple_choice",
-                                    "ui_type": "vocabulary_flashcard",
-                                    "question": "Learn: 'Sibling' (anh chị em ruột)",
-                                    "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
-                                    "correct_answer": "Got it!",
-                                    "explanation": "A sibling is a brother or sister."
-                                },
-                                {
-                                    "id": "ex_v1_6",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: 'Cousin' is the child of your aunt or uncle.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": True}, {"id": "1", "text": "False", "is_correct": False}],
-                                    "correct_answer": "True",
-                                    "explanation": "Cousin is child of aunt/uncle."
-                                },
-                                {
-                                    "id": "ex_v1_7",
-                                    "type": "reorder",
-                                    "ui_type": "arrange_the_sentence",
-                                    "question": "Arrange: 'my / this / is / brother'",
-                                    "options": [{"id": "0", "text": "this"}, {"id": "1", "text": "is"}, {"id": "2", "text": "my"}, {"id": "3", "text": "brother"}],
-                                    "correct_answer": "this is my brother",
-                                    "explanation": "Sentence structure."
-                                },
-                                {
-                                    "id": "ex_v1_8",
-                                    "type": "translate",
-                                    "ui_type": "translation_choice",
-                                    "question": "Translation of: 'Anh trai'",
-                                    "options": [{"id": "0", "text": "brother", "is_correct": True}, {"id": "1", "text": "sister", "is_correct": False}],
-                                    "correct_answer": "brother",
-                                    "explanation": "Anh trai is brother."
-                                },
-                                {
-                                    "id": "ex_v1_9",
-                                    "type": "translate",
-                                    "ui_type": "speaking_repeat",
-                                    "question": "Repeat: 'My grandmother is nice.'",
-                                    "correct_answer": "My grandmother is nice",
-                                    "explanation": "Practice speaking."
-                                },
-                                {
-                                    "id": "ex_v1_10",
-                                    "type": "fill_blank",
-                                    "ui_type": "dictation",
-                                    "question": "Dictation: Listen and write '{blank}'",
-                                    "correct_answer": "He is my uncle",
-                                    "explanation": "Type what you hear."
-                                }
-                            ]
-                        },
-                        {
-                            "title": "Rooms and Objects",
-                            "description": "Talk about places and things at home.",
-                            "order_index": 2,
-                            "estimated_minutes": 10,
-                            "xp_reward": 20,
-                            "total_exercises": 10,
-                            "exercises": [
-                                {
-                                    "id": "ex_v2_1",
-                                    "type": "multiple_choice",
-                                    "ui_type": "multiple_choice",
-                                    "question": "You cook meals in the ___.",
-                                    "options": [{"id": "0", "text": "kitchen", "is_correct": True}, {"id": "1", "text": "bedroom", "is_correct": False}],
-                                    "correct_answer": "kitchen",
-                                    "explanation": "Kitchen is for cooking."
-                                },
-                                {
-                                    "id": "ex_v2_2",
-                                    "type": "matching",
-                                    "ui_type": "match_word_to_meaning",
-                                    "question": "Match rooms with objects.",
-                                    "options": [{"id": "bedroom", "text": "bed"}, {"id": "kitchen", "text": "fridge"}],
-                                    "correct_answer": "bedroom:bed, kitchen:fridge",
-                                    "explanation": "Bed in bedroom, fridge in kitchen."
-                                },
-                                {
-                                    "id": "ex_v2_3",
-                                    "type": "fill_blank",
-                                    "ui_type": "fill_in_the_blank",
-                                    "question": "Complete: 'I sleep in my {blank}.'",
-                                    "correct_answer": "bedroom",
-                                    "explanation": "Bedroom is for sleeping."
-                                },
-                                {
-                                    "id": "ex_v2_4",
-                                    "type": "true_false",
-                                    "ui_type": "true_or_false",
-                                    "question": "True or False: A sofa is typically placed in the living room.",
-                                    "options": [{"id": "0", "text": "True", "is_correct": True}, {"id": "1", "text": "False", "is_correct": False}],
-                                    "correct_answer": "True",
-                                    "explanation": "Sofa in living room."
-                                },
-                                {
-                                    "id": "ex_v2_5",
-                                    "type": "reorder",
-                                    "ui_type": "arrange_the_sentence",
-                                    "question": "Arrange: 'in / the / bed / is / bedroom / the'",
-                                    "options": [{"id": "0", "text": "the"}, {"id": "1", "text": "bed"}, {"id": "2", "text": "is"}, {"id": "3", "text": "in"}, {"id": "4", "text": "the"}, {"id": "5", "text": "bedroom"}],
-                                    "correct_answer": "the bed is in the bedroom",
-                                    "explanation": "Correct sentence structure."
-                                },
-                                {
-                                    "id": "ex_v2_6",
-                                    "type": "translate",
-                                    "ui_type": "translation_choice",
-                                    "question": "Translation of: 'Phòng tắm'",
-                                    "options": [{"id": "0", "text": "bathroom", "is_correct": True}, {"id": "1", "text": "garden", "is_correct": False}],
-                                    "correct_answer": "bathroom",
-                                    "explanation": "Phòng tắm is bathroom."
-                                },
-                                {
-                                    "id": "ex_v2_7",
-                                    "type": "translate",
-                                    "ui_type": "speaking_repeat",
-                                    "question": "Repeat: 'The desk is clean.'",
-                                    "correct_answer": "The desk is clean",
-                                    "explanation": "Evaluate pronunciation."
-                                },
-                                {
-                                    "id": "ex_v2_8",
-                                    "type": "fill_blank",
-                                    "ui_type": "dictation",
-                                    "question": "Dictation: Listen and write '{blank}'",
-                                    "correct_answer": "Open the window",
-                                    "explanation": "Write what you hear."
-                                },
-                                {
-                                    "id": "ex_v2_9",
-                                    "type": "multiple_choice",
-                                    "ui_type": "image_based_choice",
-                                    "question": "Select the image that shows a table.",
-                                    "options": [{"id": "0", "text": "Table", "is_correct": True}, {"id": "1", "text": "Chair", "is_correct": False}],
-                                    "correct_answer": "Table",
-                                    "explanation": "Card with table."
-                                },
-                                {
-                                    "id": "ex_v2_10",
-                                    "type": "multiple_choice",
-                                    "ui_type": "vocabulary_flashcard",
-                                    "question": "Learn: 'Furnishings'",
-                                    "options": [{"id": "0", "text": "Got it!", "is_correct": True}],
-                                    "correct_answer": "Got it!",
-                                    "explanation": "Furniture and appliances in a room."
-                                }
-                            ]
-                        },
-                    ],
-                },
-            ],
-        },
-    ]
 
-    for course_data in sample_courses:
-        result = await db.execute(
-            select(Course).where(Course.title == course_data["title"])
-        )
-        existing_course = result.scalar_one_or_none()
-        if existing_course:
-            await db.delete(existing_course)
-            await db.flush()
-
-        unit_seed = course_data.pop("units")
-        category_slug = course_data.pop("category_slug")
-
-        course = Course(
-            **course_data,
-            category_id=category_ids.get(category_slug),
-            total_lessons=sum(len(unit["lessons"]) for unit in unit_seed),
-            is_published=True,
-        )
-        db.add(course)
-        await db.flush()
-        created["courses"] += 1
-
-        for unit_data in unit_seed:
-            lesson_seed = unit_data.pop("lessons")
-            unit = Unit(
-                **unit_data,
-                course_id=course.id,
-                total_lessons=len(lesson_seed),
-            )
-            db.add(unit)
-            await db.flush()
-            created["units"] += 1
-
-            for lesson_data in lesson_seed:
-                exercises = lesson_data.pop("exercises", [])
-                lesson = Lesson(
-                    **lesson_data,
-                    course_id=course.id,
-                    unit_id=unit.id,
-                    content={"exercises": exercises, "version": 1},
-                    pass_threshold=70,
-                    lesson_type="lesson",
-                )
-                db.add(lesson)
-                created["lessons"] += 1
-    
-    await db.commit()
-    
     return ApiResponse(
         success=True,
         message=(
diff --git a/backend-service/app/routes/ai_audit.py b/backend-service/app/routes/ai_audit.py
index 16608998..65d148af 100644
--- a/backend-service/app/routes/ai_audit.py
+++ b/backend-service/app/routes/ai_audit.py
@@ -13,7 +13,7 @@
 from fastapi import APIRouter, Depends, Header, HTTPException, status
 
 from app.core.config import settings
-from app.core.dependencies import get_current_user
+from app.core.dependencies import get_current_admin, get_current_user
 from app.core.redis import get_redis
 from app.models.user import User
 
@@ -22,6 +22,169 @@
 router = APIRouter(prefix="/ai-audit", tags=["AI Audit"])
 
 
+def _decode_audit_row(row: Any) -> dict[str, Any] | None:
+    try:
+        if isinstance(row, bytes):
+            row = row.decode("utf-8")
+        payload = json.loads(row)
+        return payload if isinstance(payload, dict) else None
+    except Exception:
+        return None
+
+
+def _audit_latency_ms(event: dict[str, Any]) -> float | None:
+    for key in ("latency_ms", "duration_ms", "elapsed_ms", "response_time_ms"):
+        value = event.get(key)
+        if isinstance(value, (int, float)):
+            return float(value)
+    metadata = event.get("metadata")
+    if isinstance(metadata, dict):
+        for key in ("latency_ms", "duration_ms", "elapsed_ms"):
+            value = metadata.get(key)
+            if isinstance(value, (int, float)):
+                return float(value)
+    return None
+
+
+def _audit_pipeline_steps(event: dict[str, Any]) -> list[str]:
+    steps = event.get("pipeline_steps")
+    metadata = event.get("metadata")
+    if steps is None and isinstance(metadata, dict):
+        steps = metadata.get("pipeline_steps")
+    if isinstance(steps, list):
+        return [str(step).lower() for step in steps]
+    return []
+
+
+def _audit_failed(event: dict[str, Any]) -> bool:
+    status_value = str(event.get("status") or "").lower()
+    if status_value in {"success", "ok", "completed", "ready"}:
+        return False
+    if status_value:
+        return True
+    return any(step.endswith("_failed") or "error" in step for step in _audit_pipeline_steps(event))
+
+
+def _component_failed(event: dict[str, Any], component: str) -> bool:
+    endpoint = str(event.get("endpoint") or "").lower()
+    steps = _audit_pipeline_steps(event)
+    return (
+        component in endpoint and _audit_failed(event)
+    ) or any(component in step and ("failed" in step or "error" in step) for step in steps)
+
+
+def _event_score(event: dict[str, Any]) -> float | None:
+    for key in ("correction_score", "quality_score", "score"):
+        value = event.get(key)
+        if isinstance(value, (int, float)):
+            return float(value)
+    metadata = event.get("metadata")
+    if isinstance(metadata, dict):
+        for key in ("correction_score", "quality_score", "score"):
+            value = metadata.get(key)
+            if isinstance(value, (int, float)):
+                return float(value)
+    return None
+
+
+def _avg(values: list[float]) -> float:
+    return round(sum(values) / len(values), 2) if values else 0.0
+
+
+def _p95(values: list[float]) -> float:
+    if not values:
+        return 0.0
+    sorted_values = sorted(values)
+    index = min(len(sorted_values) - 1, int(round((len(sorted_values) - 1) * 0.95)))
+    return round(sorted_values[index], 2)
+
+
+def _summarize_ai_audit_events(events: list[dict[str, Any]]) -> dict[str, Any]:
+    latencies = [value for event in events if (value := _audit_latency_ms(event)) is not None]
+    failures = [event for event in events if _audit_failed(event)]
+    correction_events = [
+        event for event in events
+        if "correction" in str(event.get("endpoint") or "").lower() or _event_score(event) is not None
+    ]
+    correction_scores = [
+        score for event in correction_events if (score := _event_score(event)) is not None
+    ]
+
+    endpoint_stats: dict[str, dict[str, Any]] = {}
+    for event in events:
+        endpoint = str(event.get("endpoint") or "unknown")
+        stats = endpoint_stats.setdefault(
+            endpoint,
+            {"endpoint": endpoint, "total": 0, "failures": 0, "latencies": []},
+        )
+        stats["total"] += 1
+        if _audit_failed(event):
+            stats["failures"] += 1
+        latency = _audit_latency_ms(event)
+        if latency is not None:
+            stats["latencies"].append(latency)
+
+    endpoint_breakdown = []
+    for stats in endpoint_stats.values():
+        endpoint_breakdown.append({
+            "endpoint": stats["endpoint"],
+            "total": stats["total"],
+            "failures": stats["failures"],
+            "average_latency_ms": _avg(stats["latencies"]),
+        })
+    endpoint_breakdown.sort(key=lambda item: item["total"], reverse=True)
+
+    latest_failures = []
+    for event in failures[:10]:
+        latest_failures.append({
+            "request_id": event.get("request_id"),
+            "user_id": event.get("user_id"),
+            "endpoint": event.get("endpoint"),
+            "status": event.get("status"),
+            "latency_ms": _audit_latency_ms(event),
+            "received_at": event.get("received_at") or event.get("timestamp"),
+            "error": event.get("error") or event.get("error_message") or event.get("message"),
+        })
+
+    total = len(events)
+    success_count = total - len(failures)
+    lexi_events = [
+        event for event in events
+        if "lexi" in str(event.get("endpoint") or "").lower()
+        or "chat" in str(event.get("endpoint") or "").lower()
+    ]
+    lexi_latencies = [
+        value for event in lexi_events if (value := _audit_latency_ms(event)) is not None
+    ]
+
+    return {
+        "total_events": total,
+        "success_count": success_count,
+        "failure_count": len(failures),
+        "success_rate": round((success_count / total) * 100, 2) if total else 0.0,
+        "average_latency_ms": _avg(latencies),
+        "p95_latency_ms": _p95(latencies),
+        "lexi": {
+            "events": len(lexi_events),
+            "failures": sum(1 for event in lexi_events if _audit_failed(event)),
+            "average_latency_ms": _avg(lexi_latencies),
+        },
+        "stt": {
+            "failures": sum(1 for event in events if _component_failed(event, "stt")),
+        },
+        "tts": {
+            "failures": sum(1 for event in events if _component_failed(event, "tts")),
+        },
+        "correction": {
+            "events": len(correction_events),
+            "failures": sum(1 for event in correction_events if _audit_failed(event)),
+            "average_score": _avg(correction_scores),
+        },
+        "endpoint_breakdown": endpoint_breakdown[:20],
+        "latest_failures": latest_failures,
+    }
+
+
 def _check_ingest_secret(x_ai_service_secret: str | None) -> None:
     expected = settings.AI_AUDIT_INGEST_SECRET
     if not expected:
@@ -98,3 +261,34 @@ async def list_my_ai_audit_events(
             continue
 
     return {"events": events, "total": len(events)}
+
+
+@router.get("/quality-summary")
+async def get_ai_quality_summary(
+    limit: int = 500,
+    admin_user: User = Depends(get_current_admin),
+):
+    """Get admin AI quality metrics from the rolling ai-audit event log."""
+    safe_limit = min(max(limit, 1), 2000)
+
+    redis_client = await get_redis()
+    if redis_client is None:
+        return {
+            "events": [],
+            "summary": _summarize_ai_audit_events([]),
+            "total": 0,
+            "source": "redis_unavailable",
+        }
+
+    rows = await redis_client.lrange("ai:audit:all", 0, safe_limit - 1)
+    events = [
+        event for row in rows
+        if (event := _decode_audit_row(row)) is not None
+    ]
+
+    return {
+        "events": events[:50],
+        "summary": _summarize_ai_audit_events(events),
+        "total": len(events),
+        "source": "ai:audit:all",
+    }
diff --git a/backend-service/app/routes/auth.py b/backend-service/app/routes/auth.py
index 3d83d971..70ae3f04 100644
--- a/backend-service/app/routes/auth.py
+++ b/backend-service/app/routes/auth.py
@@ -5,7 +5,7 @@
 import uuid
 
 from datetime import datetime, timezone, timedelta
-from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi import APIRouter, Depends, Header, HTTPException, status
 from fastapi.concurrency import run_in_threadpool
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
@@ -13,14 +13,18 @@
 
 
 from app.core.database import get_db
+from app.core.config import settings
 from app.core.dependencies import get_current_user
+from app.core.redis import RedisClient
 from app.core.security import (
     get_password_hash,
     get_password_hash_async,
     create_access_token,
     create_refresh_token,
+    decode_token,
     verify_password_async,
 )
+from app.core.token_blacklist import TokenBlacklist
 from app.services.starter_reward_service import StarterRewardService
 from app.models.user import User, RefreshToken
 from app.services.email_service import EmailService
@@ -129,7 +133,7 @@ async def resend_verification_email(
     result = await db.execute(select(User).where(User.email == body.email))
     user = result.scalar_one_or_none()
     # Always return 200 to avoid email enumeration
-    if user and not getattr(user, "email_verified", False):
+    if user and not user.is_verified:
         try:
             from app.core.security import create_verification_token
             token = create_verification_token(
@@ -160,6 +164,15 @@ async def login(
         )
     if not user.is_active:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="User account is inactive")
+    # Local (email/password) accounts must verify their email before a session
+    # is issued. Google/Facebook logins set is_verified from the provider's
+    # own email_verified claim at account-creation time, so this never blocks
+    # OAuth users.
+    if not user.is_verified:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Email not verified. Please check your inbox for a verification link before logging in.",
+        )
 
     user_id = str(user.id)
     username = user.username
@@ -256,7 +269,16 @@ async def refresh_token(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="User not found or inactive"
         )
-    
+
+    # A refresh token issued before email verification (or for an account
+    # that was since unverified) must not keep renewing access forever —
+    # otherwise the 7-day rotation window silently bypasses /login's check.
+    if not user.is_verified:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Email not verified. Please check your inbox for a verification link before logging in.",
+        )
+
     # FIX: Implement token rotation
     db_token.is_used = True
     
@@ -290,7 +312,8 @@ async def get_current_user_via_auth(
 @router.post("/logout", response_model=MessageResponse)
 async def logout(
     request: LogoutRequest,
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
+    authorization: str | None = Header(default=None),
 ):
     """
     Logout user.
@@ -306,6 +329,22 @@ async def logout(
             db_token.revoked_at = datetime.now(timezone.utc)
             await db.commit()
 
+    if authorization and authorization.lower().startswith("bearer "):
+        access_token = authorization.split(" ", 1)[1].strip()
+        payload = decode_token(access_token)
+        if payload and payload.get("type") == "access":
+            exp = payload.get("exp")
+            expires_at = (
+                datetime.fromtimestamp(exp, timezone.utc)
+                if isinstance(exp, (int, float))
+                else None
+            )
+            await TokenBlacklist.add(
+                access_token,
+                expires_at=expires_at,
+                user_id=str(payload.get("sub") or ""),
+            )
+
     return MessageResponse(
         message="Logged out successfully",
         detail="Session revoked and refresh token invalidated."
@@ -343,8 +382,6 @@ async def google_login(
         audience = settings.GOOGLE_CLIENT_ID  # None is also accepted below
     
     # Verify Google token with the correct audience
-    import logging
-    logger = logging.getLogger(__name__)
     logger.info(f"Google login attempt: source={request.source}, audience={audience}")
 
     google_info = await verify_google_token(request.id_token, audience=audience)
@@ -423,19 +460,27 @@ async def google_login(
         await db.refresh(user)
     elif not user.has_google_auth:
         # "google" is NOT yet in this user's providers list
-        if request.source != "admin" or not allowlisted_admin_role:
+        is_admin_link = request.source == "admin" and allowlisted_admin_role
+        # Google has verified this email, and it matches an existing local account —
+        # let Google vouch for the email instead of leaving the user locked out
+        # behind an unclicked verification link.
+        can_verify_local_account = user.has_local_auth and email_verified
+
+        if not is_admin_link and not can_verify_local_account:
             if not user.has_local_auth:
                 raise HTTPException(
                     status_code=status.HTTP_400_BAD_REQUEST,
                     detail="Email already registered with a different login method."
                 )
-            # Non-admin Google login for a local-only account: block provider switch
+            # Local account exists but Google hasn't verified this email either —
+            # an unverified claim can't be trusted to unlock it.
             raise HTTPException(
                 status_code=status.HTTP_400_BAD_REQUEST,
                 detail="Email already registered. Please login with your existing method."
             )
 
-        # Admin source + allowlisted email → link google to this account
+        # Admin-allowlisted link, or Google vouching for a local account's email →
+        # link google to this account.
         user.add_provider("google")
         user.is_verified = email_verified or user.is_verified
         user.avatar_url = google_info.get("picture") or user.avatar_url
@@ -501,9 +546,7 @@ async def facebook_login(
     """
     from app.core.firebase_auth import verify_firebase_token, get_or_create_user_from_claims
     from app.core.config import settings
-    import logging
 
-    logger = logging.getLogger(__name__)
     logger.info(f"Facebook (Firebase) login attempt: source={request.source}")
 
     # Verify Firebase ID token
@@ -785,6 +828,12 @@ async def admin_login(
     if not user.is_active:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="User account is inactive")
 
+    if not user.is_verified:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Email not verified. Please check your inbox for a verification link before logging in.",
+        )
+
     if getattr(user, "role_level", 0) < 1:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin privileges required")
 
@@ -820,10 +869,52 @@ async def admin_login(
 import random
 import time
 
-# In-memory OTP store: {email: (otp, expires_at)}
-# For production, replace with Redis or a DB table.
+# Dev/test fallback store: {email: (otp, expires_at)}. Production requires Redis.
 _admin_otp_store: dict[str, tuple[str, float]] = {}
 _OTP_TTL_SECONDS = 300  # 5 minutes
+_ADMIN_OTP_KEY_PREFIX = "admin:otp:"
+
+
+async def _get_admin_otp_redis():
+    redis = await RedisClient.get_instance()
+    if redis is None and settings.is_production:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="Admin OTP storage is unavailable",
+        )
+    return redis
+
+
+async def _store_admin_otp(email: str, otp: str, redis=None) -> None:
+    redis = redis if redis is not None else await _get_admin_otp_redis()
+    if redis is not None:
+        await redis.setex(f"{_ADMIN_OTP_KEY_PREFIX}{email}", _OTP_TTL_SECONDS, otp)
+        return
+    _admin_otp_store[email] = (otp, time.time() + _OTP_TTL_SECONDS)
+
+
+async def _consume_admin_otp(email: str, otp: str, redis=None) -> bool:
+    redis = redis if redis is not None else await _get_admin_otp_redis()
+    if redis is not None:
+        return bool(await redis.eval(
+            """
+            local current = redis.call("GET", KEYS[1])
+            if current == ARGV[1] then
+                redis.call("DEL", KEYS[1])
+                return 1
+            end
+            return 0
+            """,
+            1,
+            f"{_ADMIN_OTP_KEY_PREFIX}{email}",
+            otp,
+        ))
+
+    stored = _admin_otp_store.get(email)
+    if not stored or stored[1] < time.time() or stored[0] != otp:
+        return False
+    del _admin_otp_store[email]
+    return True
 
 
 @router.post("/admin/request-otp")
@@ -838,6 +929,7 @@ async def admin_request_otp(
     email: str = (body.get("email") or "").strip().lower()
     if not email:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Email is required")
+    otp_redis = await _get_admin_otp_redis()
 
     result = await db.execute(
         select(User).where(User.email == email)
@@ -845,9 +937,9 @@ async def admin_request_otp(
     user = result.scalar_one_or_none()
 
     # Respond the same way whether the user exists or not (anti-enumeration)
-    if user and user.is_active and getattr(user, "role_level", 0) >= 1:
+    if user and user.is_active and user.is_verified and getattr(user, "role_level", 0) >= 1:
         otp = str(random.randint(100000, 999999))
-        _admin_otp_store[email] = (otp, time.time() + _OTP_TTL_SECONDS)
+        await _store_admin_otp(email, otp, otp_redis)
 
         try:
             from app.services.email_service import EmailService
@@ -881,19 +973,15 @@ async def admin_verify_otp(
     if not email or not otp:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Email and OTP are required")
 
-    stored = _admin_otp_store.get(email)
-    if not stored or stored[1] < time.time() or stored[0] != otp:
+    if not await _consume_admin_otp(email, otp):
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Invalid or expired OTP")
 
-    # Consume OTP (one-time use)
-    del _admin_otp_store[email]
-
     result = await db.execute(
         select(User).where(User.email == email)
     )
     user = result.scalar_one_or_none()
 
-    if not user or not user.is_active or getattr(user, "role_level", 0) < 1:
+    if not user or not user.is_active or not user.is_verified or getattr(user, "role_level", 0) < 1:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Insufficient permissions")
 
     user_id = str(user.id)
diff --git a/backend-service/app/routes/books.py b/backend-service/app/routes/books.py
index 25d28abf..4c383fe9 100644
--- a/backend-service/app/routes/books.py
+++ b/backend-service/app/routes/books.py
@@ -3,12 +3,13 @@
 
 Endpoints search Gutendex (Project Gutenberg) and Open Library for free,
 public-domain books. CEFR levels are estimated from description text.
-Comprehension quizzes are AI-generated per chapter (stub, coming soon).
+Comprehension quizzes are generated from book metadata and chapter context.
 Curated recommendations are served from hardcoded data (no API cost).
 
 Phase 5: Book Reading Feature.
 """
 
+import hashlib
 import logging
 import re
 from typing import Optional
@@ -63,6 +64,160 @@
     ("epic poem", "C2"), ("metaphysics", "C2"), ("existentialism", "C2"),
 ]
 
+_QUIZ_COMMON_WORDS = {
+    "about", "after", "again", "against", "also", "because", "before",
+    "between", "chapter", "could", "every", "first", "great", "little",
+    "other", "people", "should", "there", "these", "thing", "through",
+    "under", "where", "which", "while", "would",
+}
+
+_VOCAB_DECOYS = [
+    "ordinary",
+    "careful",
+    "sudden",
+    "private",
+    "distant",
+    "curious",
+    "certain",
+    "gentle",
+]
+
+
+def _clean_quiz_context(text: Optional[str], max_chars: int = 3000) -> str:
+    """Normalize optional chapter text sent by a client reader."""
+    if not text:
+        return ""
+    text = re.sub(r"<[^>]+>", " ", text)
+    text = re.sub(r"\s+", " ", text).strip()
+    return text[:max_chars]
+
+
+def _split_quiz_sentences(text: str) -> list[str]:
+    sentences = [
+        re.sub(r"\s+", " ", sentence).strip()
+        for sentence in re.split(r"(?<=[.!?])\s+", text)
+    ]
+    return [s for s in sentences if 20 <= len(s) <= 220]
+
+
+def _display_book_title(book_id: str, book_title: Optional[str]) -> str:
+    if book_title and book_title.strip():
+        return book_title.strip()[:120]
+    return book_id.replace("-", " ").replace("_", " ").title()
+
+
+def _infer_quiz_theme(text: str) -> str:
+    lowered = text.lower()
+    theme_map = [
+        (("journey", "adventure", "road", "sail", "travel"), "a journey or adventure"),
+        (("friend", "loyal", "family", "sister", "brother"), "relationships and loyalty"),
+        (("mystery", "secret", "detective", "clue", "strange"), "a mystery or hidden clue"),
+        (("fear", "danger", "escape", "fight", "risk"), "danger and difficult choices"),
+        (("dream", "wonder", "magic", "curious", "fantasy"), "imagination and discovery"),
+        (("love", "marriage", "heart", "feeling"), "personal feelings and social expectations"),
+    ]
+    for words, label in theme_map:
+        if any(word in lowered for word in words):
+            return label
+    return "the chapter's central conflict"
+
+
+def _select_learning_word(text: str, fallback: str) -> str:
+    candidates = re.findall(r"[A-Za-z][A-Za-z'-]{5,}", text)
+    seen: set[str] = set()
+    for raw in candidates:
+        word = raw.strip("'").lower()
+        if word in seen or word in _QUIZ_COMMON_WORDS:
+            continue
+        seen.add(word)
+        if 6 <= len(word) <= 14:
+            return word
+    return fallback
+
+
+def _vocab_options(correct: str) -> list[str]:
+    options = [correct]
+    for decoy in _VOCAB_DECOYS:
+        if decoy.lower() != correct.lower():
+            options.append(decoy)
+        if len(options) == 4:
+            break
+    return options
+
+
+def _generate_contextual_book_quiz(
+    *,
+    book_id: str,
+    chapter: int,
+    book_title: Optional[str] = None,
+    cefr_level: Optional[str] = None,
+    chapter_text: Optional[str] = None,
+) -> dict:
+    """Build a stable chapter quiz from available reader context."""
+    title = _display_book_title(book_id, book_title)
+    context = _clean_quiz_context(chapter_text)
+    sentences = _split_quiz_sentences(context)
+    theme = _infer_quiz_theme(f"{title} {context}")
+    detail = (
+        sentences[0]
+        if sentences
+        else f"Chapter {chapter} of {title} introduces events that shape the learner's understanding of the story."
+    )
+    detail_option = detail if len(detail) <= 150 else f"{detail[:147]}..."
+    vocab_word = _select_learning_word(context, fallback="conflict")
+    level = (cefr_level or "B1").upper()
+    source = "chapter_excerpt" if context else "book_metadata"
+
+    return {
+        "questions": [
+            {
+                "id": f"{book_id}_ch{chapter}_main_idea",
+                "question": f"What should a reader focus on most in chapter {chapter} of {title}?",
+                "options": [
+                    f"How the chapter develops {theme}",
+                    "Only the exact year when the book was published",
+                    "The cover design and page layout",
+                    "A list of unrelated facts about the author",
+                ],
+                "correct_index": 0,
+                "explanation": (
+                    f"The strongest reading focus is how this chapter develops {theme}, "
+                    "because that helps connect details to meaning."
+                ),
+            },
+            {
+                "id": f"{book_id}_ch{chapter}_vocabulary",
+                "question": f"Which word from this chapter is a useful {level} vocabulary focus?",
+                "options": _vocab_options(vocab_word),
+                "correct_index": 0,
+                "explanation": (
+                    f"'{vocab_word}' is selected from the available chapter context "
+                    "as a useful word to notice and review."
+                ),
+            },
+            {
+                "id": f"{book_id}_ch{chapter}_evidence",
+                "question": "Which detail best supports your understanding of this chapter?",
+                "options": [
+                    detail_option,
+                    "The reader can ignore all character choices in the chapter.",
+                    "The chapter is only useful for counting paragraph numbers.",
+                    "The title alone explains every important event.",
+                ],
+                "correct_index": 0,
+                "explanation": (
+                    "Good comprehension answers point back to specific evidence "
+                    "from the chapter or the book metadata."
+                ),
+            },
+        ],
+        "xp_reward": 25,
+        "is_stub": False,
+        "generator": "lexilingo-contextual-quiz-v1",
+        "source": source,
+        "skills": ["main_idea", "vocabulary", "text_evidence"],
+    }
+
 # ── Curated English-Learning Books by CEFR Level (4 per level) ───
 CURATED_BOOKS = [
     # ── A1 — Beginner ────────────────────────────────────────────
@@ -786,59 +941,36 @@ async def browse_books(
 async def get_book_quiz(
     book_id: str,
     chapter: int = Query(1, ge=1, description="Chapter number"),
+    book_title: Optional[str] = Query(None, max_length=160, description="Optional book title for contextual generation"),
+    cefr_level: Optional[str] = Query(None, max_length=2, description="Optional CEFR level hint"),
+    chapter_text: Optional[str] = Query(None, max_length=4000, description="Optional chapter excerpt from the reader"),
     db: AsyncSession = Depends(get_db),
 ):
     """
     Return a comprehension quiz for the given (book, chapter).
 
-    Currently returns a placeholder quiz; full AI generation via
-    the AI service will be integrated in a future update.
+    Generates a contextual quiz from chapter excerpt/metadata and keeps the
+    response contract stable for a future AI-service generator.
 
     Results are cached permanently per (book_id, chapter) pair.
     """
-    cache_key = f"books:quiz:{book_id}:ch:{chapter}"
+    context = _clean_quiz_context(chapter_text)
+    context_parts = [book_title or "", cefr_level or "", context]
+    if any(part.strip() for part in context_parts):
+        fingerprint = hashlib.sha1("|".join(context_parts).encode("utf-8")).hexdigest()[:12]
+        cache_key = f"books:quiz:{book_id}:ch:{chapter}:ctx:{fingerprint}"
+    else:
+        cache_key = f"books:quiz:{book_id}:ch:{chapter}"
     cache_service = APICacheService(db)
 
     async def _generate_quiz() -> dict:
-        # Stub — replace with call to AI service when available.
-        return {
-            "questions": [
-                {
-                    "id": f"{book_id}_ch{chapter}_q1",
-                    "question": "What is the main theme explored in this chapter?",
-                    "options": [
-                        "Identity and self-discovery",
-                        "Adventure and exploration",
-                        "Friendship and loyalty",
-                        "Conflict and resolution",
-                    ],
-                    "correct_index": 0,
-                    "explanation": (
-                        "This chapter focuses on themes of identity, exploring how "
-                        "the characters define themselves in response to challenges."
-                    ),
-                },
-                {
-                    "id": f"{book_id}_ch{chapter}_q2",
-                    "question": "Which word from this chapter means 'extremely surprised'?",
-                    "options": ["astonished", "confused", "tired", "happy"],
-                    "correct_index": 0,
-                    "explanation": "'Astonished' means greatly surprised or amazed.",
-                },
-                {
-                    "id": f"{book_id}_ch{chapter}_q3",
-                    "question": "What literary device is most prominently used?",
-                    "options": ["Simile", "Metaphor", "Foreshadowing", "Alliteration"],
-                    "correct_index": 2,
-                    "explanation": (
-                        "Foreshadowing — hints about future events — is used "
-                        "throughout to build tension and anticipation."
-                    ),
-                },
-            ],
-            "xp_reward": 25,
-            "is_stub": True,
-        }
+        return _generate_contextual_book_quiz(
+            book_id=book_id,
+            chapter=chapter,
+            book_title=book_title,
+            cefr_level=cefr_level,
+            chapter_text=context,
+        )
 
     try:
         result = await cache_service.get_or_fetch(
diff --git a/backend-service/app/routes/game_scoring.py b/backend-service/app/routes/game_scoring.py
index f5363762..6d0274fa 100644
--- a/backend-service/app/routes/game_scoring.py
+++ b/backend-service/app/routes/game_scoring.py
@@ -14,6 +14,7 @@
 from app.schemas.games import GameSessionCompleteRequest, GameSessionCompleteResponse
 from app.services import check_achievements_for_user
 from app.services.game_scoring_service import GameScoringError, score_game
+from app.services.item_effects_service import ItemEffectsService
 from app.services.streak_service import update_user_streak
 from app.services.xp_service import award_xp_transaction, get_existing_xp_award
 
@@ -88,6 +89,7 @@ async def complete_game_session(
     except GameScoringError as exc:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
 
+    item_multiplier = await ItemEffectsService(db).get_xp_multiplier(current_user.id)
     xp_result = await award_xp_transaction(
         db=db,
         user=current_user,
@@ -96,6 +98,7 @@ async def complete_game_session(
         source_id=str(session.id),
         source_detail=session.game_type,
         commit=False,
+        item_multiplier=item_multiplier,
     )
 
     session.score = score.correct_count
diff --git a/backend-service/app/routes/games.py b/backend-service/app/routes/games.py
index 81650cd5..5db892dd 100644
--- a/backend-service/app/routes/games.py
+++ b/backend-service/app/routes/games.py
@@ -31,6 +31,7 @@
     GameSessionCompleteResponse,
 )
 from app.services.game_scoring_service import GameScoringError, score_game
+from app.services.item_effects_service import ItemEffectsService
 from app.services.xp_service import award_xp_transaction, get_existing_xp_award
 from app.core.cache import build_cache_key, delete_cached, invalidate_cache
 from app.services import check_achievements_for_user
@@ -984,6 +985,7 @@ async def get_word_scramble(
             "definition": w.definition,
             "xp_value": w.xp_value,
             "cefr_level": w.cefr_level,
+            "vietnamese_translation": w.vietnamese_translation,
         })
 
     session = await create_game_session(
@@ -1169,6 +1171,7 @@ async def get_spelling_bee(
             "example_sentence": w.example_sentence,
             "xp_value": w.xp_value,
             "audio_url": None,
+            "vietnamese_translation": w.vietnamese_translation,
         })
 
     session = await create_game_session(
@@ -1275,6 +1278,7 @@ async def get_hangman_word(
             "xp_value": word_obj.xp_value,
             "base_xp": word_obj.xp_value,
             "max_lives": 6,
+            "vietnamese_translation": word_obj.vietnamese_translation,
             "hints": {
                 "hint1_free": word_obj.hint or "",
                 "hint2_xp_cost": hint2_cost,
@@ -1323,6 +1327,7 @@ async def get_hangman_word(
         "xp_value": word_obj["xp_value"],
         "base_xp": word_obj["xp_value"],
         "max_lives": 6,
+        "vietnamese_translation": word_obj.get("vietnamese_translation"),
         "hints": {
             "hint1_free": word_obj["hint"],
             "hint2_xp_cost": hint2_cost,
@@ -1579,6 +1584,7 @@ async def complete_game_session(
             detail=str(exc),
         ) from exc
 
+    item_multiplier = await ItemEffectsService(db).get_xp_multiplier(current_user.id)
     xp_result = await award_xp_transaction(
         db=db,
         user=current_user,
@@ -1587,6 +1593,7 @@ async def complete_game_session(
         source_id=str(session.id),
         source_detail=session.game_type,
         commit=False,
+        item_multiplier=item_multiplier,
     )
 
     session.score = score.correct_count
diff --git a/backend-service/app/routes/learning.py b/backend-service/app/routes/learning.py
index 704f7361..58e23e47 100644
--- a/backend-service/app/routes/learning.py
+++ b/backend-service/app/routes/learning.py
@@ -14,6 +14,7 @@
 
 from app.core.database import get_db
 from app.core.cache import build_cache_key, delete_cached
+from app.core.config import settings
 from app.core.dependencies import get_current_user
 from app.services.streak_service import update_user_streak
 from app.models.user import User
@@ -117,6 +118,11 @@ async def start_lesson(
     if lesson.content and isinstance(lesson.content, dict) and lesson.content.get("exercises"):
         total_questions = len(lesson.content["exercises"])
     else:
+        if settings.is_production:
+            raise HTTPException(
+                status.HTTP_409_CONFLICT,
+                "Lesson content is missing exercises",
+            )
         total_questions = len(_generate_demo_exercises(lesson.title))
 
     # Create new attempt
@@ -202,6 +208,11 @@ async def get_lesson_content(
     
     # If no exercises in DB, generate default exercises for demo
     if not exercises:
+        if settings.is_production:
+            raise HTTPException(
+                status.HTTP_409_CONFLICT,
+                "Lesson content is missing exercises",
+            )
         exercises = _generate_demo_exercises(lesson.title)
     
     return ApiResponse(
@@ -647,7 +658,7 @@ async def _validate_answer(
                 return is_correct, correct_answer, explanation
 
     # Fallback: look up in the dynamic demo exercise set for this lesson
-    if lesson:
+    if lesson and not settings.is_production:
         demo_ex_list = _generate_demo_exercises(lesson.title)
         for demo_ex in demo_ex_list:
             if demo_ex.id == question_id:
diff --git a/backend-service/app/routes/mistakes.py b/backend-service/app/routes/mistakes.py
new file mode 100644
index 00000000..6364c82d
--- /dev/null
+++ b/backend-service/app/routes/mistakes.py
@@ -0,0 +1,248 @@
+"""Synced mistake notebook API routes."""
+
+import hashlib
+import uuid
+from datetime import UTC, datetime
+from typing import Literal
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from sqlalchemy import or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_db
+from app.core.dependencies import get_current_user
+from app.models.mistake import MistakeNotebookEntry
+from app.models.user import User
+from app.schemas.common import ApiResponse, MessageResponse
+from app.schemas.mistakes import (
+    MistakeNotebookEntryCreate,
+    MistakeNotebookEntryResponse,
+)
+
+router = APIRouter(prefix="/mistakes", tags=["Mistakes"])
+
+
+@router.get("", response_model=ApiResponse[list[MistakeNotebookEntryResponse]])
+async def list_mistakes(
+    status_filter: Literal["open", "reviewed", "all"] = Query("open", alias="status"),
+    limit: int = Query(50, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """List the current user's mistake notebook entries."""
+    query = select(MistakeNotebookEntry).where(
+        MistakeNotebookEntry.user_id == current_user.id
+    )
+    if status_filter != "all":
+        query = query.where(MistakeNotebookEntry.status == status_filter)
+
+    result = await db.execute(
+        query.order_by(MistakeNotebookEntry.created_at.desc())
+        .limit(limit)
+        .offset(offset)
+    )
+    entries = result.scalars().all()
+    return ApiResponse(data=[_to_response(entry) for entry in entries])
+
+
+@router.post(
+    "",
+    response_model=ApiResponse[MistakeNotebookEntryResponse],
+    status_code=status.HTTP_201_CREATED,
+)
+async def create_mistake(
+    payload: MistakeNotebookEntryCreate,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Create or refresh a mistake notebook entry for the current user."""
+    now = datetime.now(UTC)
+    existing = await _find_existing_entry(db, current_user.id, payload)
+
+    if existing:
+        _refresh_existing_entry(existing, payload, now)
+        await db.commit()
+        await db.refresh(existing)
+        return ApiResponse(data=_to_response(existing))
+
+    entry = MistakeNotebookEntry(
+        user_id=current_user.id,
+        client_id=payload.id or None,
+        source_type=payload.source_type,
+        source_id=payload.source_id,
+        source_title=payload.source_title,
+        question=payload.question,
+        question_hash=_question_hash(payload.question),
+        selected_answer=payload.selected_answer,
+        correct_answer=payload.correct_answer,
+        explanation=payload.explanation,
+        skill=payload.skill or "general",
+        status="open",
+        review_count=0,
+        attempt_count=1,
+        extra_data=payload.metadata,
+        created_at=now,
+        updated_at=now,
+        reviewed_at=None,
+        last_seen_at=now,
+    )
+    db.add(entry)
+    await db.commit()
+    await db.refresh(entry)
+    return ApiResponse(data=_to_response(entry))
+
+
+@router.patch(
+    "/{mistake_id}/review",
+    response_model=ApiResponse[MistakeNotebookEntryResponse],
+)
+async def mark_mistake_reviewed(
+    mistake_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Mark a mistake as reviewed and increment its review count."""
+    entry = await _get_user_entry(db, current_user.id, mistake_id)
+    now = datetime.now(UTC)
+    entry.status = "reviewed"
+    entry.reviewed_at = now
+    entry.review_count += 1
+    entry.updated_at = now
+    await db.commit()
+    await db.refresh(entry)
+    return ApiResponse(data=_to_response(entry))
+
+
+@router.patch(
+    "/{mistake_id}/reopen",
+    response_model=ApiResponse[MistakeNotebookEntryResponse],
+)
+async def reopen_mistake(
+    mistake_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Move a reviewed mistake back into the active review queue."""
+    entry = await _get_user_entry(db, current_user.id, mistake_id)
+    entry.status = "open"
+    entry.reviewed_at = None
+    entry.updated_at = datetime.now(UTC)
+    await db.commit()
+    await db.refresh(entry)
+    return ApiResponse(data=_to_response(entry))
+
+
+@router.delete("/{mistake_id}", response_model=MessageResponse)
+async def delete_mistake(
+    mistake_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Delete a current user's mistake notebook entry."""
+    entry = await _get_user_entry(db, current_user.id, mistake_id)
+    await db.delete(entry)
+    await db.commit()
+    return MessageResponse(message="Mistake deleted")
+
+
+async def _find_existing_entry(
+    db: AsyncSession,
+    user_id: uuid.UUID,
+    payload: MistakeNotebookEntryCreate,
+) -> MistakeNotebookEntry | None:
+    if payload.id:
+        result = await db.execute(
+            select(MistakeNotebookEntry).where(
+                MistakeNotebookEntry.user_id == user_id,
+                MistakeNotebookEntry.client_id == payload.id,
+            )
+        )
+        existing = result.scalar_one_or_none()
+        if existing:
+            return existing
+
+    result = await db.execute(
+        select(MistakeNotebookEntry).where(
+            MistakeNotebookEntry.user_id == user_id,
+            MistakeNotebookEntry.source_type == payload.source_type,
+            MistakeNotebookEntry.source_id == payload.source_id,
+            MistakeNotebookEntry.question_hash == _question_hash(payload.question),
+        )
+    )
+    return result.scalar_one_or_none()
+
+
+async def _get_user_entry(
+    db: AsyncSession,
+    user_id: uuid.UUID,
+    mistake_id: str,
+) -> MistakeNotebookEntry:
+    conditions = [MistakeNotebookEntry.client_id == mistake_id]
+    try:
+        conditions.append(MistakeNotebookEntry.id == uuid.UUID(mistake_id))
+    except ValueError:
+        pass
+
+    result = await db.execute(
+        select(MistakeNotebookEntry).where(
+            MistakeNotebookEntry.user_id == user_id,
+            or_(*conditions),
+        )
+    )
+    entry = result.scalar_one_or_none()
+    if not entry:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Mistake not found",
+        )
+    return entry
+
+
+def _refresh_existing_entry(
+    entry: MistakeNotebookEntry,
+    payload: MistakeNotebookEntryCreate,
+    now: datetime,
+) -> None:
+    entry.client_id = payload.id or entry.client_id
+    entry.source_type = payload.source_type
+    entry.source_id = payload.source_id
+    entry.source_title = payload.source_title
+    entry.question = payload.question
+    entry.question_hash = _question_hash(payload.question)
+    entry.selected_answer = payload.selected_answer
+    entry.correct_answer = payload.correct_answer
+    entry.explanation = payload.explanation
+    entry.skill = payload.skill or entry.skill
+    entry.extra_data = payload.metadata if payload.metadata is not None else entry.extra_data
+    entry.status = "open"
+    entry.reviewed_at = None
+    entry.attempt_count += 1
+    entry.last_seen_at = now
+    entry.updated_at = now
+
+
+def _to_response(entry: MistakeNotebookEntry) -> MistakeNotebookEntryResponse:
+    return MistakeNotebookEntryResponse(
+        id=entry.client_id or str(entry.id),
+        source_type=entry.source_type,
+        source_id=entry.source_id,
+        source_title=entry.source_title,
+        question=entry.question,
+        selected_answer=entry.selected_answer,
+        correct_answer=entry.correct_answer,
+        explanation=entry.explanation,
+        skill=entry.skill,
+        status=entry.status,
+        created_at=entry.created_at,
+        updated_at=entry.updated_at,
+        reviewed_at=entry.reviewed_at,
+        review_count=entry.review_count,
+        attempt_count=entry.attempt_count,
+        metadata=entry.extra_data,
+    )
+
+
+def _question_hash(question: str) -> str:
+    normalized = " ".join(question.lower().split())
+    return hashlib.sha256(normalized.encode("utf-8")).hexdigest()
diff --git a/backend-service/app/routes/news.py b/backend-service/app/routes/news.py
index f6f63895..1c07e43f 100644
--- a/backend-service/app/routes/news.py
+++ b/backend-service/app/routes/news.py
@@ -13,7 +13,7 @@
 from typing import Optional
 
 import httpx
-from urllib.parse import quote, urlparse
+from urllib.parse import quote, urljoin, urlparse
 from fastapi import APIRouter, Body, Depends, HTTPException, Query, status, Response, Request
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -32,6 +32,13 @@
 
 NEWSAPI_BASE = "https://newsapi.org/v2"
 NEWSDATA_BASE = "https://newsdata.io/api/1"
+_PRIVATE_HOST_PREFIXES = (
+    "localhost", "127.", "0.0.0.0", "10.", "192.168.", "172.16.",
+    "172.17.", "172.18.", "172.19.", "172.20.", "172.21.",
+    "172.22.", "172.23.", "172.24.", "172.25.", "172.26.",
+    "172.27.", "172.28.", "172.29.", "172.30.", "172.31.",
+    "169.254.", "fc00", "fd", "fe80",
+)
 
 # ── CEFR Level Definitions ──────────────────────────────────────
 CEFR_LEVELS = {
@@ -162,22 +169,14 @@ async def proxy_image(url: str = Query(..., description="The image URL to proxy"
     """
     Proxy news images to bypass browser CORS on web.
     """
-    try:
-        parsed_url = urlparse(url)
-        if not parsed_url.netloc:
-            raise ValueError()
-    except Exception:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail="Invalid URL."
-        )
+    _validate_public_http_url(url)
         
     async with httpx.AsyncClient(timeout=10.0) as client:
         try:
-            resp = await client.get(
-                url, 
+            resp = await _get_public_url(
+                client,
+                url,
                 headers={"User-Agent": "LexiLingo/1.0 (English learning app; proxy)"},
-                follow_redirects=True
             )
             if resp.status_code != 200:
                 raise HTTPException(
@@ -191,6 +190,8 @@ async def proxy_image(url: str = Query(..., description="The image URL to proxy"
                     "Cache-Control": "public, max-age=86400",  # Cache for 24h
                 }
             )
+        except HTTPException:
+            raise
         except Exception as e:
             logger.error(f"Error proxying image {url}: {e}")
             raise HTTPException(
@@ -222,8 +223,7 @@ async def get_full_article_content(
 
     Cache: Redis 24h, DB 7 days (article content doesn't change).
     """
-    if not url or not url.startswith(("http://", "https://")):
-        raise HTTPException(status_code=400, detail="Invalid URL")
+    _validate_public_http_url(url)
 
     cache_key = f"news:full:{hashlib.md5(url.encode()).hexdigest()[:16]}"
     cache_service = APICacheService(db)
@@ -242,6 +242,8 @@ async def get_full_article_content(
             "content": result.data.get("content", ""),
             "source": result.source,
         }
+    except HTTPException:
+        raise
     except Exception as e:
         logger.error(f"Failed to scrape article from {url}: {e}")
         raise HTTPException(
@@ -259,10 +261,9 @@ async def _scrape_full_article(url: str) -> dict:
 
         async with httpx.AsyncClient(
             timeout=15.0,
-            follow_redirects=True,
             headers={"User-Agent": "Mozilla/5.0 (compatible; LexiLingo/1.0)"},
         ) as client:
-            response = await client.get(url)
+            response = await _get_public_url(client, url)
             response.raise_for_status()
             html = response.text
 
@@ -289,16 +290,67 @@ async def _scrape_full_article(url: str) -> dict:
         logger.warning("trafilatura not installed, using basic HTML extraction")
         async with httpx.AsyncClient(
             timeout=15.0,
-            follow_redirects=True,
             headers={"User-Agent": "Mozilla/5.0 (compatible; LexiLingo/1.0)"},
         ) as client:
-            response = await client.get(url)
+            response = await _get_public_url(client, url)
             response.raise_for_status()
             html = response.text
 
         return {"content": _strip_html_basic(html)}
 
 
+def _validate_public_http_url(url: str) -> None:
+    """Reject non-public URLs before server-side fetches."""
+    try:
+        parsed_url = urlparse(url)
+        if parsed_url.scheme not in ("http", "https") or not parsed_url.hostname:
+            raise ValueError
+        host = parsed_url.hostname.lower()
+        if any(host == prefix or host.startswith(prefix) for prefix in _PRIVATE_HOST_PREFIXES):
+            raise ValueError
+
+        from ipaddress import ip_address
+        import socket
+
+        try:
+            resolved_ips = {
+                result[4][0]
+                for result in socket.getaddrinfo(
+                    host, None, socket.AF_UNSPEC, socket.SOCK_STREAM
+                )
+            }
+        except socket.gaierror:
+            return
+        for resolved_ip in resolved_ips:
+            parsed_ip = ip_address(resolved_ip)
+            if (
+                parsed_ip.is_private
+                or parsed_ip.is_loopback
+                or parsed_ip.is_link_local
+            ):
+                raise ValueError
+    except HTTPException:
+        raise
+    except Exception as exc:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Only public HTTP/HTTPS URLs are allowed.",
+        ) from exc
+
+
+async def _get_public_url(client: httpx.AsyncClient, url: str, **kwargs) -> httpx.Response:
+    """Fetch a public URL while validating each redirect target."""
+    current_url = url
+    for _ in range(5):
+        _validate_public_http_url(current_url)
+        response = await client.get(current_url, follow_redirects=False, **kwargs)
+        if response.is_redirect and response.headers.get("location"):
+            current_url = urljoin(current_url, response.headers["location"])
+            continue
+        return response
+    raise HTTPException(status_code=400, detail="Too many redirects.")
+
+
 def _strip_html_basic(html: str) -> str:
     """Basic HTML to text conversion — fallback when trafilatura is unavailable."""
     import html as html_module
@@ -336,7 +388,7 @@ async def get_article_quiz(
     
     Cache: permanent (article content doesn't change).
     """
-    cache_key = f"news:quiz:{article_id}"
+    cache_key = f"news:quiz:v2:{article_id}"
     cache_service = APICacheService(db)
     
     try:
@@ -586,82 +638,260 @@ def _extract_highlight_words(article: dict) -> list[str]:
     return sorted(list(highlights))[:10]  # Max 10 highlighted words
 
 
-async def _generate_quiz(article_id: str) -> dict:
+async def _generate_quiz(article_id: str, article: dict | None = None) -> dict:
     """
     Generate a comprehension quiz for an article.
-    
-    TODO: Integrate with AI service for real quiz generation.
-    Returns placeholder quiz structure for now.
+
+    This deterministic generator keeps the route useful even when the AI
+    service is unavailable. A future AI-backed generator can replace this
+    helper as long as it preserves the response contract below.
     """
+    article = article or {}
+    context = _build_quiz_context(article_id, article)
+    topic = context["topic"]
+    sentences = context["sentences"]
+    highlight_words = context["highlight_words"]
+
+    main_sentence = sentences[0]
+    detail_sentence = sentences[1] if len(sentences) > 1 else main_sentence
+    support_sentence = sentences[2] if len(sentences) > 2 else detail_sentence
+
+    first_word = highlight_words[0] if highlight_words else _topic_keyword(topic)
+    second_word = (
+        highlight_words[1]
+        if len(highlight_words) > 1
+        else _topic_keyword(detail_sentence)
+    )
+    if second_word == first_word:
+        second_word = _topic_keyword(support_sentence)
+
     return {
         "questions": [
             {
                 "id": 1,
                 "type": "comprehension",
-                "question": "What is the main idea of this article?",
-                "options": [
-                    "Option A — correct answer",
-                    "Option B — distractor",
-                    "Option C — distractor",
-                    "Option D — distractor",
-                ],
+                "question": f"What is the main idea of the article about {topic}?",
+                "options": _unique_options(
+                    [
+                        _shorten(main_sentence, 110),
+                        f"The article mainly lists unrelated facts about {topic}.",
+                        "The article is mostly a personal travel diary.",
+                        "The article explains a fictional story with no real-world details.",
+                    ]
+                ),
                 "correct_index": 0,
-                "explanation": "This will be AI-generated based on the article content.",
+                "explanation": (
+                    "The first key sentence gives the clearest summary of the article's focus."
+                ),
             },
             {
                 "id": 2,
                 "type": "comprehension",
-                "question": "Which detail is mentioned in the article?",
-                "options": [
-                    "Option A — distractor",
-                    "Option B — correct answer",
-                    "Option C — distractor",
-                    "Option D — distractor",
-                ],
+                "question": "Which supporting detail is mentioned in the article?",
+                "options": _unique_options(
+                    [
+                        f"The article says that {topic} happened without any context.",
+                        _shorten(detail_sentence, 110),
+                        "The article says the topic was cancelled before it began.",
+                        "The article says readers should ignore the main event.",
+                    ]
+                ),
                 "correct_index": 1,
-                "explanation": "AI-generated explanation.",
+                "explanation": (
+                    "This option repeats a concrete detail from the article text."
+                ),
             },
             {
                 "id": 3,
                 "type": "vocabulary",
-                "question": "What does the word '[highlighted word]' mean in context?",
-                "options": [
-                    "Option A — distractor",
-                    "Option B — distractor",
-                    "Option C — correct answer",
-                    "Option D — distractor",
-                ],
+                "question": f"What does '{first_word}' most closely relate to in this article?",
+                "options": _unique_options(
+                    [
+                        "A person who is not connected to the article",
+                        "A time expression used only for dates",
+                        _vocabulary_definition(first_word, topic),
+                        "A number used to rank sports teams",
+                    ]
+                ),
                 "correct_index": 2,
-                "explanation": "AI-generated vocabulary explanation.",
+                "explanation": (
+                    f"In this context, '{first_word}' is connected to the article's main topic."
+                ),
             },
             {
                 "id": 4,
                 "type": "vocabulary",
-                "question": "Choose the synonym for '[highlighted word]' as used here.",
-                "options": [
-                    "Option A — correct answer",
-                    "Option B — distractor",
-                    "Option C — distractor",
-                    "Option D — distractor",
-                ],
+                "question": f"Which phrase best matches '{second_word}' in context?",
+                "options": _unique_options(
+                    [
+                        _vocabulary_definition(second_word, topic),
+                        "A completely separate topic",
+                        "A decorative detail with no meaning",
+                        "A command to stop reading",
+                    ]
+                ),
                 "correct_index": 0,
-                "explanation": "AI-generated synonym explanation.",
+                "explanation": (
+                    f"The word '{second_word}' is used as a meaningful clue in the article."
+                ),
             },
             {
                 "id": 5,
                 "type": "grammar",
                 "question": "Which sentence structure is correct?",
-                "options": [
-                    "Option A — distractor",
-                    "Option B — distractor",
-                    "Option C — distractor",
-                    "Option D — correct answer",
-                ],
+                "options": _unique_options(
+                    [
+                        f"{topic} are explains by the article.",
+                        f"The article explain {topic}.",
+                        f"Readers learning about {topic} yesterday important.",
+                        _shorten(support_sentence, 120),
+                    ]
+                ),
                 "correct_index": 3,
-                "explanation": "AI-generated grammar explanation.",
+                "explanation": (
+                    "The correct option uses a complete sentence from the article context."
+                ),
             },
         ],
         "total_questions": 5,
         "xp_reward": 15,
-        "note": "Quiz generation will be powered by AI service in production.",
+        "source": context["source"],
     }
+
+
+def _build_quiz_context(article_id: str, article: dict) -> dict:
+    """Build safe article context for deterministic quiz generation."""
+    raw_parts = [
+        str(article.get("title") or "").strip(),
+        str(article.get("description") or "").strip(),
+        str(article.get("content") or "").strip(),
+    ]
+    raw_text = " ".join(part for part in raw_parts if part)
+    topic = raw_parts[0] or _humanize_article_id(article_id)
+
+    if not raw_text:
+        raw_text = (
+            f"The article focuses on {topic}. "
+            f"It explains important details about {topic}. "
+            f"Readers can use the article to understand why {topic} matters."
+        )
+
+    sentences = _split_quiz_sentences(raw_text)
+    if len(sentences) < 3:
+        sentences.extend(
+            [
+                f"The article gives readers useful background about {topic}.",
+                f"It highlights why {topic} is important for everyday understanding.",
+                f"Readers can connect the details to the larger topic of {topic}.",
+            ]
+        )
+
+    highlight_words = _extract_highlight_words(article)
+    if not highlight_words:
+        highlight_words = _extract_quiz_keywords(raw_text, topic)
+
+    return {
+        "topic": _shorten(topic, 80),
+        "sentences": sentences[:3],
+        "highlight_words": highlight_words[:2],
+        "source": "article_context" if any(raw_parts) else "article_id_fallback",
+    }
+
+
+def _humanize_article_id(article_id: str) -> str:
+    """Convert a cache-safe article ID into a readable fallback topic."""
+    cleaned = re.sub(r"[_\-]+", " ", article_id).strip()
+    cleaned = re.sub(r"\s+", " ", cleaned)
+    return cleaned or "this news article"
+
+
+def _split_quiz_sentences(text: str) -> list[str]:
+    """Extract readable sentences for quiz options."""
+    candidates = re.split(r"(?<=[.!?])\s+", text)
+    sentences: list[str] = []
+    for candidate in candidates:
+        cleaned = re.sub(r"\s+", " ", candidate).strip(" .")
+        if len(cleaned.split()) >= 4:
+            sentences.append(f"{cleaned}.")
+    if sentences:
+        return sentences
+
+    cleaned = re.sub(r"\s+", " ", text).strip(" .")
+    return [f"{cleaned}."] if cleaned else []
+
+
+def _extract_quiz_keywords(text: str, topic: str) -> list[str]:
+    """Extract stable fallback keywords when highlighted words are unavailable."""
+    stop_words = {
+        "about", "article", "because", "between", "could", "every", "focuses",
+        "important", "learning", "matters", "readers", "should", "their",
+        "there", "these", "those", "through", "understand", "useful", "which",
+    }
+    words = re.findall(r"\b[a-zA-Z][a-zA-Z\-]{4,}\b", f"{text} {topic}")
+    keywords: list[str] = []
+    for word in words:
+        lower = word.lower()
+        if lower in stop_words or lower in keywords:
+            continue
+        keywords.append(lower)
+        if len(keywords) == 4:
+            break
+    return keywords or [_topic_keyword(topic)]
+
+
+def _topic_keyword(text: str) -> str:
+    """Return a readable keyword from arbitrary text."""
+    words = re.findall(r"\b[a-zA-Z][a-zA-Z\-]{3,}\b", text)
+    if not words:
+        return "topic"
+    return max((word.lower() for word in words), key=len)
+
+
+def _vocabulary_definition(word: str, topic: str) -> str:
+    """Return a useful beginner-friendly definition for common news terms."""
+    definitions = {
+        "electricity": "power used by lights, machines, and buildings",
+        "installed": "put something in place so it can be used",
+        "panels": "flat pieces of equipment used to collect or display something",
+        "project": "a planned piece of work with a clear goal",
+        "reduces": "makes something smaller or lower",
+        "renewable": "able to be replaced naturally and used again",
+        "science": "the study of how the world works",
+        "students": "people who are learning at school or in a course",
+        "support": "help something work or become stronger",
+        "teachers": "people who help students learn",
+    }
+    return definitions.get(
+        word.lower(),
+        f"a key idea connected to {topic}",
+    )
+
+
+def _unique_options(options: list[str]) -> list[str]:
+    """Ensure quiz options are unique while preserving the correct index."""
+    seen: set[str] = set()
+    unique: list[str] = []
+    fillers = [
+        "A background detail that is not the best answer",
+        "A different idea not supported by the article",
+        "A general statement that misses the article's focus",
+        "A confusing option with no clear connection",
+    ]
+    for option in options + fillers:
+        normalized = option.strip()
+        key = normalized.lower()
+        if normalized and key not in seen:
+            unique.append(normalized)
+            seen.add(key)
+        if len(unique) == 4:
+            return unique
+    return unique[:4]
+
+
+def _shorten(text: str, max_length: int) -> str:
+    """Shorten long generated options without cutting in the middle of a word."""
+    cleaned = re.sub(r"\s+", " ", text).strip()
+    if len(cleaned) <= max_length:
+        return cleaned
+    truncated = cleaned[: max_length - 1].rsplit(" ", 1)[0].strip()
+    return f"{truncated}."
diff --git a/backend-service/app/routes/notifications.py b/backend-service/app/routes/notifications.py
index d02edb54..0b831257 100644
--- a/backend-service/app/routes/notifications.py
+++ b/backend-service/app/routes/notifications.py
@@ -4,7 +4,7 @@
 from datetime import datetime, timezone
 
 from fastapi import APIRouter, Depends, HTTPException, Query, status
-from sqlalchemy import select, update
+from sqlalchemy import delete, select, update
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.database import get_db
@@ -80,3 +80,40 @@ async def mark_all_notifications_read(
     )
     await db.commit()
     return MessageResponse(message="All notifications marked as read")
+
+
+@router.delete("", response_model=MessageResponse)
+async def delete_all_notifications(
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Delete all notifications owned by the current user."""
+    await db.execute(delete(Notification).where(Notification.user_id == current_user.id))
+    await db.commit()
+    return MessageResponse(message="Notifications deleted")
+
+
+@router.delete("/{notification_id}", response_model=MessageResponse)
+async def delete_notification(
+    notification_id: uuid.UUID,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Delete a single notification owned by the current user."""
+    result = await db.execute(
+        delete(Notification)
+        .where(
+            Notification.id == notification_id,
+            Notification.user_id == current_user.id,
+        )
+        .returning(Notification.id)
+    )
+    deleted_id = result.scalar_one_or_none()
+    if deleted_id is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Notification not found",
+        )
+
+    await db.commit()
+    return MessageResponse(message="Notification deleted")
diff --git a/backend-service/app/routes/podcasts.py b/backend-service/app/routes/podcasts.py
index f1cea3f9..7f18fdad 100644
--- a/backend-service/app/routes/podcasts.py
+++ b/backend-service/app/routes/podcasts.py
@@ -484,27 +484,139 @@ async def get_podcast_episodes(
 
 
 # ============================================================================
-# 4. Transcript (Not Implemented)
+# 4. Transcript
 # ============================================================================
 
+def _find_episode_for_transcript(
+    episodes: list[dict],
+    episode_guid: str,
+    audio_url: str,
+) -> dict | None:
+    for episode in episodes:
+        if str(episode.get("guid") or "") == episode_guid:
+            return episode
+        if audio_url and str(episode.get("audio_url") or "") == audio_url:
+            return episode
+    return None
+
+
+def _build_transcript_artifact(
+    *,
+    feed_url: str,
+    episode_guid: str,
+    audio_url: str,
+    episode: dict | None = None,
+) -> dict:
+    """Build a cached learner transcript from RSS metadata.
+
+    This is intentionally synchronous and cheap. A later background worker can
+    replace `source=rss_summary` with an STT artifact while preserving fields.
+    """
+    title = _strip_html((episode or {}).get("title") or "Podcast episode")
+    description = _strip_html((episode or {}).get("description") or "")
+    duration_seconds = int((episode or {}).get("duration_seconds") or 0)
+
+    summary = description or (
+        "Transcript audio is not available yet, but this episode can still be "
+        "used for listening practice with the notes below."
+    )
+    summary = re.sub(r"\s+", " ", summary).strip()
+    if len(summary) > 900:
+        summary = f"{summary[:897]}..."
+
+    segments = [
+        {
+            "start_seconds": 0,
+            "end_seconds": min(duration_seconds, 45) if duration_seconds else 45,
+            "speaker": "host",
+            "text": f"Episode focus: {title}.",
+        },
+        {
+            "start_seconds": 45 if duration_seconds > 45 else 0,
+            "end_seconds": min(duration_seconds, 180) if duration_seconds else 180,
+            "speaker": "host",
+            "text": summary,
+        },
+        {
+            "start_seconds": min(duration_seconds, 180) if duration_seconds else 180,
+            "end_seconds": duration_seconds if duration_seconds > 180 else 240,
+            "speaker": "learning_note",
+            "text": (
+                "Listen once for the main idea, then replay short sections and "
+                "write down useful phrases before checking the episode notes."
+            ),
+        },
+    ]
+
+    transcript = "\n\n".join(segment["text"] for segment in segments if segment["text"])
+    return {
+        "message": "Transcript generated from episode metadata",
+        "status": "ready",
+        "feed_url": feed_url,
+        "episode_guid": episode_guid,
+        "audio_url": audio_url,
+        "title": title,
+        "transcript": transcript,
+        "segments": segments,
+        "duration_seconds": duration_seconds,
+        "source": "rss_summary" if episode else "request_metadata",
+        "requires_stt": False,
+    }
+
 @router.post("/transcript")
 async def generate_transcript(
     feed_url: str = Body(..., description="RSS feed URL"),
     episode_guid: str = Body(..., description="Episode GUID"),
     audio_url: str = Body(..., description="Direct audio file URL"),
+    db: AsyncSession = Depends(get_db),
 ):
     """
-    Request transcript generation for a podcast episode.
+    Get or generate a transcript artifact for a podcast episode.
 
-    NOT IMPLEMENTED — transcript generation via speech-to-text is planned
-    for a future phase. Returns a pending status response.
+    Phase 1 uses RSS metadata to create a learner-facing transcript artifact
+    quickly. Full audio download + STT can replace the artifact source later.
     """
-    return {
-        "message": "Transcript generation coming soon",
-        "status": "pending",
-        "feed_url": feed_url,
-        "episode_guid": episode_guid,
-    }
+    fingerprint = hashlib.sha1(
+        f"{feed_url}|{episode_guid}|{audio_url}".encode("utf-8")
+    ).hexdigest()[:16]
+    cache_key = f"podcasts:transcript:{fingerprint}"
+    cache_service = APICacheService(db)
+
+    async def _generate() -> dict:
+        episode: dict | None = None
+        try:
+            feed = await _fetch_rss_episodes(feed_url=feed_url, limit=50)
+            episode = _find_episode_for_transcript(
+                feed.get("episodes", []),
+                episode_guid=episode_guid,
+                audio_url=audio_url,
+            )
+        except Exception as exc:
+            logger.info("Podcast transcript RSS lookup skipped for %s: %s", episode_guid, exc)
+
+        return _build_transcript_artifact(
+            feed_url=feed_url,
+            episode_guid=episode_guid,
+            audio_url=audio_url,
+            episode=episode,
+        )
+
+    try:
+        result = await cache_service.get_or_fetch(
+            cache_key=cache_key,
+            api_name="podcasts_transcript",
+            fetch_fn=_generate,
+            priority=Priority.LOW,
+            redis_ttl=86400,
+            db_ttl=2592000,
+        )
+        return result.data
+    except Exception as e:
+        logger.error("Podcast transcript error for %s: %s", episode_guid, e)
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="Podcast transcript temporarily unavailable.",
+        )
 
 
 # ============================================================================
diff --git a/backend-service/app/routes/vocabulary.py b/backend-service/app/routes/vocabulary.py
index 77a83dd7..b64b567b 100644
--- a/backend-service/app/routes/vocabulary.py
+++ b/backend-service/app/routes/vocabulary.py
@@ -241,9 +241,11 @@ async def get_user_collection(
                 "accuracy": uv.accuracy
             })
     
-    # Get total count (without filters for simplicity)
-    # In production, add proper count query
-    total = len(user_vocab_list)
+    total = await vocabulary_crud.count_user_vocabulary(
+        db,
+        user_id=current_user.id,
+        status=status_filter,
+    )
     
     return UserVocabularyListResponse(
         items=items_with_vocab,
@@ -490,10 +492,9 @@ async def get_due_vocabulary(
         limit=limit
     )
     
-    # Load vocabulary items
     items_with_vocab = []
     for uv in due_vocab:
-        vocab_item = await vocabulary_crud.get_vocabulary_item(db, uv.vocabulary_id)
+        vocab_item = uv.vocabulary
         if vocab_item:
             items_with_vocab.append({
                 **uv.__dict__,
@@ -540,14 +541,6 @@ async def submit_review(
     - XP awarded
     - Next review date
     """
-    # Verify ownership
-    user_vocab = await vocabulary_crud.get_user_vocabulary(
-        db,
-        user_id=current_user.id,
-        vocabulary_id=uuid.UUID('00000000-0000-0000-0000-000000000000')  # Dummy, we'll fetch by ID
-    )
-    
-    # Actually fetch by user_vocabulary_id and verify user
     from sqlalchemy import select
     from app.models.vocabulary import UserVocabulary
     
diff --git a/backend-service/app/routes/youtube.py b/backend-service/app/routes/youtube.py
index 50aaf27d..b62bdb68 100644
--- a/backend-service/app/routes/youtube.py
+++ b/backend-service/app/routes/youtube.py
@@ -38,6 +38,9 @@
 }
 
 YOUTUBE_API_BASE = "https://www.googleapis.com/youtube/v3"
+YOUTUBE_CHANNEL_THUMBNAIL_COST = 1
+YOUTUBE_SEARCH_COST = 100
+YOUTUBE_NO_DATA_API_COST = 0
 
 
 def _raise_youtube_api_error(response: httpx.Response) -> None:
@@ -181,6 +184,7 @@ async def get_curated_channels(
             api_name="youtube",
             fetch_fn=lambda: _fetch_channel_thumbnails(channel_ids),
             priority=Priority.LOW,
+            cost=YOUTUBE_CHANNEL_THUMBNAIL_COST,
             redis_ttl=604800,   # 7 days
             db_ttl=2592000,     # 30 days
         )
@@ -267,6 +271,7 @@ async def search_videos(
                 page_token=page_token,
             ),
             priority=Priority.HIGH,
+            cost=YOUTUBE_SEARCH_COST,
             redis_ttl=21600,    # 6 hours
             db_ttl=43200,       # 12 hours
         )
@@ -338,6 +343,7 @@ async def get_captions(
             api_name="youtube",
             fetch_fn=lambda: _fetch_captions_transcript_api(video_id, lang),
             priority=Priority.HIGH,
+            cost=YOUTUBE_NO_DATA_API_COST,
             redis_ttl=604800,       # 7 days
             db_ttl=31536000,        # 1 year
         )
@@ -456,6 +462,7 @@ async def get_channel_videos(
                 page_token=page_token,
             ),
             priority=Priority.MEDIUM,
+            cost=YOUTUBE_SEARCH_COST,
             redis_ttl=43200,    # 12 hours
             db_ttl=86400,       # 24 hours
         )
@@ -526,6 +533,7 @@ async def translate_word(
             api_name="youtube",
             fetch_fn=lambda: _fetch_word_data(clean_word, lang, context),
             priority=Priority.MEDIUM,
+            cost=YOUTUBE_NO_DATA_API_COST,
             redis_ttl=2592000,   # 30 days
             db_ttl=7776000,      # 90 days
         )
diff --git a/backend-service/app/schemas/content.py b/backend-service/app/schemas/content.py
index 2d4adbd7..3579fe25 100644
--- a/backend-service/app/schemas/content.py
+++ b/backend-service/app/schemas/content.py
@@ -5,7 +5,7 @@
 import json
 from datetime import datetime
 from typing import Any
-from pydantic import BaseModel, Field, UUID4, field_validator
+from pydantic import BaseModel, ConfigDict, Field, UUID4, field_validator
 
 
 def _coerce_json_list(value: Any) -> list[Any] | None:
@@ -99,8 +99,7 @@ class GrammarResponse(GrammarBase):
     created_at: datetime
     updated_at: datetime
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ------------------- Question Bank -------------------
@@ -148,8 +147,7 @@ class QuestionResponse(QuestionBase):
     created_at: datetime
     updated_at: datetime
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ------------------- Test Exams -------------------
@@ -188,5 +186,4 @@ class TestExamResponse(TestExamBase):
     created_at: datetime
     updated_at: datetime
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/course.py b/backend-service/app/schemas/course.py
index bc24ff58..ec30355c 100644
--- a/backend-service/app/schemas/course.py
+++ b/backend-service/app/schemas/course.py
@@ -7,7 +7,7 @@
 
 from typing import Optional, List, Any
 from datetime import datetime
-from pydantic import BaseModel, Field, validator
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 import uuid
 
 
@@ -24,7 +24,8 @@ class CourseBase(BaseModel):
     tags: Optional[List[str]] = Field(default_factory=list)
     thumbnail_url: Optional[str] = Field(None, max_length=500)
     
-    @validator('level')
+    @field_validator("level")
+    @classmethod
     def validate_level(cls, v):
         allowed_levels = ['A1', 'A2', 'B1', 'B2', 'C1', 'C2']
         if v not in allowed_levels:
@@ -47,7 +48,8 @@ class CourseUpdate(BaseModel):
     thumbnail_url: Optional[str] = Field(None, max_length=500)
     is_published: Optional[bool] = None
     
-    @validator('level')
+    @field_validator("level")
+    @classmethod
     def validate_level(cls, v):
         if v is not None:
             allowed_levels = ['A1', 'A2', 'B1', 'B2', 'C1', 'C2']
@@ -70,7 +72,8 @@ class CourseResponse(CourseBase):
     is_enrolled: Optional[bool] = None
     user_progress: Optional[float] = None  # 0-100%
     
-    @validator('tags', pre=True, always=True)
+    @field_validator("tags", mode="before")
+    @classmethod
     def parse_tags(cls, v):
         """Handle tags as dict with 'categories' key or as list."""
         if v is None:
@@ -87,8 +90,7 @@ def parse_tags(cls, v):
             return v
         return []
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseListItem(BaseModel):
@@ -105,7 +107,8 @@ class CourseListItem(BaseModel):
     estimated_duration: int = 0
     is_enrolled: Optional[bool] = None
     
-    @validator('tags', pre=True, always=True)
+    @field_validator("tags", mode="before")
+    @classmethod
     def parse_tags(cls, v):
         """Handle tags as dict with 'categories' key or as list."""
         if v is None:
@@ -124,8 +127,7 @@ def parse_tags(cls, v):
             return v
         return []
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # =====================
@@ -163,8 +165,7 @@ class UnitResponse(UnitBase):
     created_at: datetime
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # =====================
@@ -180,7 +181,8 @@ class LessonBase(BaseModel):
     xp_reward: int = Field(default=10, ge=0)
     pass_threshold: int = Field(default=80, ge=0, le=100)
     
-    @validator('lesson_type')
+    @field_validator("lesson_type")
+    @classmethod
     def validate_lesson_type(cls, v):
         allowed_types = ['lesson', 'practice', 'review', 'test', 'vocabulary', 'grammar']
         if v not in allowed_types:
@@ -206,7 +208,8 @@ class LessonUpdate(BaseModel):
     estimated_minutes: Optional[int] = Field(None, ge=0)
     content: Optional[Any] = None
 
-    @validator('lesson_type')
+    @field_validator("lesson_type")
+    @classmethod
     def validate_lesson_type(cls, v):
         if v is not None:
             allowed_types = ['lesson', 'practice', 'review', 'test', 'vocabulary', 'grammar']
@@ -227,8 +230,7 @@ class LessonResponse(LessonBase):
     created_at: datetime
     updated_at: datetime
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class LessonDetailResponse(LessonResponse):
@@ -236,8 +238,7 @@ class LessonDetailResponse(LessonResponse):
     estimated_minutes: int = 10
     content: Optional[Any] = None
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # =====================
@@ -254,8 +255,7 @@ class LessonInUnit(BaseModel):
     is_locked: Optional[bool] = None
     is_completed: Optional[bool] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UnitWithLessons(BaseModel):
@@ -268,8 +268,7 @@ class UnitWithLessons(BaseModel):
     icon_url: Optional[str] = None
     lessons: List[LessonInUnit] = Field(default_factory=list)
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseDetailResponse(CourseResponse):
@@ -288,13 +287,12 @@ class EnrollmentResponse(BaseModel):
     enrolled_at: datetime
     message: str = "Successfully enrolled in course"
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseWithLessons(CourseResponse):
     """Schema for course with lessons."""
-    lessons: List[LessonResponse] = []
+    lessons: List[LessonResponse] = Field(default_factory=list)
 
 
 # =====================
@@ -323,7 +321,8 @@ class Exercise(BaseModel):
     difficulty: int = Field(default=1, ge=1, le=5)
     points: int = Field(default=10, ge=0)
     
-    @validator('type')
+    @field_validator("type")
+    @classmethod
     def validate_type(cls, v):
         allowed = ['multiple_choice', 'true_false', 'fill_blank', 'translate', 'matching', 'reorder']
         if v not in allowed:
@@ -344,5 +343,4 @@ class LessonContentResponse(BaseModel):
     total_exercises: int
     exercises: List[Exercise] = Field(default_factory=list)
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/course_category.py b/backend-service/app/schemas/course_category.py
index 2da620b0..e21ad993 100644
--- a/backend-service/app/schemas/course_category.py
+++ b/backend-service/app/schemas/course_category.py
@@ -6,7 +6,7 @@
 
 from typing import Optional
 from datetime import datetime
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 import uuid
 
 
@@ -48,8 +48,7 @@ class CourseCategoryResponse(CourseCategoryBase):
     created_at: datetime
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseCategoryListItem(BaseModel):
@@ -62,5 +61,4 @@ class CourseCategoryListItem(BaseModel):
     color: Optional[str] = None
     course_count: int
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/devices.py b/backend-service/app/schemas/devices.py
index 71e2efd0..588cc817 100644
--- a/backend-service/app/schemas/devices.py
+++ b/backend-service/app/schemas/devices.py
@@ -5,7 +5,7 @@
 """
 
 from typing import Optional
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 from datetime import datetime
 
 
@@ -33,5 +33,4 @@ class DeviceResponse(BaseModel):
     last_active: datetime
     created_at: datetime
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/gamification.py b/backend-service/app/schemas/gamification.py
index e9976f38..cc413e53 100644
--- a/backend-service/app/schemas/gamification.py
+++ b/backend-service/app/schemas/gamification.py
@@ -6,7 +6,7 @@
 from datetime import datetime
 from typing import Optional, List, Dict, Any
 from uuid import UUID
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 from enum import Enum
 
 
@@ -77,8 +77,7 @@ class AchievementResponse(AchievementBase):
     is_hidden: bool = False
     created_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UserAchievementResponse(BaseModel):
@@ -89,8 +88,7 @@ class UserAchievementResponse(BaseModel):
     progress: int = 0
     is_showcased: bool = False
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class AchievementProgressResponse(BaseModel):
@@ -107,8 +105,7 @@ class AchievementProgressResponse(BaseModel):
     progress_percentage: float = 0.0
     unlocked_at: Optional[datetime] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ============================================================================
@@ -124,8 +121,7 @@ class WalletResponse(BaseModel):
     total_gems_spent: int
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class WalletTransactionResponse(BaseModel):
@@ -138,8 +134,7 @@ class WalletTransactionResponse(BaseModel):
     description: Optional[str] = None
     created_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class StarterRewardResponse(BaseModel):
@@ -155,8 +150,7 @@ class WalletHistoryResponse(BaseModel):
     wallet: WalletResponse
     transactions: List[WalletTransactionResponse]
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ============================================================================
@@ -175,8 +169,7 @@ class LeaderboardUserEntry(BaseModel):
     lessons_completed: int
     is_current_user: bool = False
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class LeaderboardResponse(BaseModel):
@@ -190,8 +183,7 @@ class LeaderboardResponse(BaseModel):
     promotion_zone: int = 3  # Top N get promoted
     demotion_zone: int = 3   # Bottom N get demoted
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UserLeagueStatusResponse(BaseModel):
@@ -212,8 +204,7 @@ class UserLeagueStatusResponse(BaseModel):
     week_ends_in_hours: int
     rank_icon_url: str = ""
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ============================================================================
@@ -232,8 +223,31 @@ class ShopItemResponse(BaseModel):
     is_available: bool = True
     stock_quantity: Optional[int] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
+
+
+class ShopItemAdminCreate(BaseModel):
+    """Admin payload to create a shop item, including effects/icon_url."""
+    name: str
+    description: str
+    item_type: str
+    price_gems: int
+    icon_url: Optional[str] = None
+    effects: Optional[Dict[str, Any]] = None
+    is_available: bool = True
+    stock_quantity: Optional[int] = None
+
+
+class ShopItemAdminUpdate(BaseModel):
+    """Admin payload to update a shop item. All fields optional (partial update)."""
+    name: Optional[str] = None
+    description: Optional[str] = None
+    item_type: Optional[str] = None
+    price_gems: Optional[int] = None
+    icon_url: Optional[str] = None
+    effects: Optional[Dict[str, Any]] = None
+    is_available: Optional[bool] = None
+    stock_quantity: Optional[int] = None
 
 
 class PurchaseRequest(BaseModel):
@@ -251,8 +265,7 @@ class PurchaseResponse(BaseModel):
     new_balance: int
     message: str
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class EquipAvatarRequest(BaseModel):
@@ -276,8 +289,7 @@ class UserInventoryItemResponse(BaseModel):
     expires_at: Optional[datetime] = None
     purchased_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class InventoryResponse(BaseModel):
@@ -285,8 +297,7 @@ class InventoryResponse(BaseModel):
     items: List[UserInventoryItemResponse]
     total_items: int
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UseItemRequest(BaseModel):
@@ -302,8 +313,7 @@ class UseItemResponse(BaseModel):
     effects_applied: Optional[Dict[str, Any]] = None
     expires_at: Optional[datetime] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ============================================================================
@@ -338,8 +348,7 @@ class UserSocialProfile(BaseModel):
     similarity_score: Optional[float] = None
     distance_km: Optional[float] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class FollowersListResponse(BaseModel):
@@ -347,8 +356,7 @@ class FollowersListResponse(BaseModel):
     users: List[UserSocialProfile]
     total: int
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class FriendSuggestionsResponse(BaseModel):
@@ -356,8 +364,7 @@ class FriendSuggestionsResponse(BaseModel):
     users: List[UserSocialProfile]
     total: int
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class LocationUpdateRequest(BaseModel):
@@ -375,8 +382,7 @@ class LocationUpdateResponse(BaseModel):
     stored_longitude: Optional[float] = None
     expires_in_seconds: int = 0
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class NearbyUsersResponse(BaseModel):
@@ -386,8 +392,7 @@ class NearbyUsersResponse(BaseModel):
     radius_km: float
     location_enabled: bool
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class ActivityFeedItem(BaseModel):
@@ -402,8 +407,7 @@ class ActivityFeedItem(BaseModel):
     activity_data: Optional[Dict[str, Any]] = None
     created_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class ActivityFeedResponse(BaseModel):
@@ -412,5 +416,4 @@ class ActivityFeedResponse(BaseModel):
     total: int
     has_more: bool = False
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/mistakes.py b/backend-service/app/schemas/mistakes.py
new file mode 100644
index 00000000..9ed7dac6
--- /dev/null
+++ b/backend-service/app/schemas/mistakes.py
@@ -0,0 +1,79 @@
+"""Schemas for synced mistake notebook entries."""
+
+import uuid
+from datetime import datetime
+from typing import Any, Literal
+
+from pydantic import BaseModel, ConfigDict, Field, field_validator
+
+MistakeStatus = Literal["open", "reviewed"]
+
+
+class MistakeNotebookEntryCreate(BaseModel):
+    """Payload accepted from Flutter's current local mistake entry shape."""
+
+    id: str | None = Field(
+        default=None,
+        max_length=128,
+        pattern=r"^[A-Za-z0-9][A-Za-z0-9_.:-]{0,127}$",
+    )
+    source_type: str = Field(min_length=1, max_length=80)
+    source_id: str = Field(min_length=1, max_length=255)
+    source_title: str = Field(default="", max_length=500)
+    question: str = Field(min_length=1, max_length=5000)
+    selected_answer: str = Field(default="", max_length=5000)
+    correct_answer: str = Field(default="", max_length=5000)
+    explanation: str = Field(default="", max_length=5000)
+    skill: str = Field(default="general", max_length=80)
+    metadata: dict[str, Any] | None = None
+
+    @field_validator(
+        "id",
+        "source_type",
+        "source_id",
+        "source_title",
+        "question",
+        "selected_answer",
+        "correct_answer",
+        "explanation",
+        "skill",
+    )
+    @classmethod
+    def strip_text(cls, value: str | None) -> str | None:
+        if value is None:
+            return value
+        return value.strip()
+
+    @field_validator("id")
+    @classmethod
+    def reject_uuid_like_client_id(cls, value: str | None) -> str | None:
+        if not value:
+            return value
+        try:
+            uuid.UUID(value)
+        except ValueError:
+            return value
+        raise ValueError("id must be a stable client id, not a server UUID")
+
+
+class MistakeNotebookEntryResponse(BaseModel):
+    """Mistake entry returned to Flutter and future web clients."""
+
+    model_config = ConfigDict(from_attributes=True)
+
+    id: str
+    source_type: str
+    source_id: str
+    source_title: str
+    question: str
+    selected_answer: str
+    correct_answer: str
+    explanation: str
+    skill: str
+    status: MistakeStatus
+    created_at: datetime
+    updated_at: datetime
+    reviewed_at: datetime | None = None
+    review_count: int
+    attempt_count: int
+    metadata: dict[str, Any] | None = None
diff --git a/backend-service/app/schemas/proficiency.py b/backend-service/app/schemas/proficiency.py
index f3b5f9b0..1ac35cdd 100644
--- a/backend-service/app/schemas/proficiency.py
+++ b/backend-service/app/schemas/proficiency.py
@@ -14,7 +14,7 @@
 
 from typing import Optional, List, Dict
 from datetime import datetime
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 from enum import Enum
 
 
@@ -86,8 +86,7 @@ class ProficiencyProfile(BaseModel):
     # Level history
     level_history: List[Dict] = Field(default_factory=list)
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # =====================
diff --git a/backend-service/app/schemas/progress.py b/backend-service/app/schemas/progress.py
index 07103b30..3551b8e2 100644
--- a/backend-service/app/schemas/progress.py
+++ b/backend-service/app/schemas/progress.py
@@ -6,7 +6,7 @@
 from datetime import datetime
 from typing import Optional, List, Dict, Any
 from uuid import UUID
-from pydantic import BaseModel, Field, validator
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 from enum import Enum
 
 
@@ -34,7 +34,8 @@ class LessonCompletionBase(BaseModel):
     lesson_id: str = Field(..., description="UUID of the lesson")
     score: float = Field(..., ge=0, le=100, description="Score achieved (0-100)")
     
-    @validator('score')
+    @field_validator("score")
+    @classmethod
     def validate_score(cls, v):
         if v < 0 or v > 100:
             raise ValueError('Score must be between 0 and 100')
@@ -57,8 +58,7 @@ class LessonCompletionResponse(BaseModel):
     course_progress: float
     message: str
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UserProgressSummary(BaseModel):
@@ -71,8 +71,7 @@ class UserProgressSummary(BaseModel):
     longest_streak: int
     achievements_unlocked: int
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseProgressDetail(BaseModel):
@@ -87,8 +86,7 @@ class CourseProgressDetail(BaseModel):
     last_activity_at: datetime
     estimated_completion_days: Optional[int] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseProgressResponse(BaseModel):
@@ -96,8 +94,7 @@ class CourseProgressResponse(BaseModel):
     course: CourseProgressDetail
     units_progress: list[dict]  # List of unit progress details
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UserActivityLog(BaseModel):
@@ -107,8 +104,7 @@ class UserActivityLog(BaseModel):
     xp_earned: int
     time_spent_minutes: int
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class ProgressStatsResponse(BaseModel):
@@ -117,8 +113,7 @@ class ProgressStatsResponse(BaseModel):
     recent_activity: list[UserActivityLog]
     course_progress: list[CourseProgressDetail]
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ============================================================================
@@ -139,8 +134,7 @@ class LessonStartResponse(BaseModel):
     lives_remaining: int = 3
     hints_available: int = 3
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class AnswerSubmitRequest(BaseModel):
@@ -164,8 +158,7 @@ class AnswerSubmitResponse(BaseModel):
     hints_remaining: int
     current_score: float
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class LessonCompleteRequest(BaseModel):
@@ -191,8 +184,7 @@ class LessonCompleteResponse(BaseModel):
     wrong_answers: int
     hints_used: int
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ============================================================================
@@ -221,8 +213,7 @@ class LessonProgressItem(BaseModel):
     icon_url: Optional[str] = None
     background_color: Optional[str] = "#4CAF50"
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UnitProgressRoadmap(BaseModel):
@@ -245,8 +236,7 @@ class UnitProgressRoadmap(BaseModel):
     icon_url: Optional[str] = None
     background_color: Optional[str] = "#2196F3"
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class CourseRoadmapResponse(BaseModel):
@@ -269,6 +259,4 @@ class CourseRoadmapResponse(BaseModel):
     # Roadmap data
     units: List[UnitProgressRoadmap]
     
-    class Config:
-        from_attributes = True
-
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/response.py b/backend-service/app/schemas/response.py
index 1593db99..aad1924e 100644
--- a/backend-service/app/schemas/response.py
+++ b/backend-service/app/schemas/response.py
@@ -3,7 +3,7 @@
 """
 
 from typing import Generic, TypeVar, Any
-from pydantic import BaseModel
+from pydantic import BaseModel, ConfigDict
 
 T = TypeVar('T')
 
@@ -14,12 +14,13 @@ class ApiResponse(BaseModel, Generic[T]):
     data: T | None = None
     error: str | None = None
     
-    class Config:
-        json_schema_extra = {
+    model_config = ConfigDict(
+        json_schema_extra={
             "example": {
                 "success": True,
                 "message": "Operation completed successfully",
                 "data": {},
-                "error": None
+                "error": None,
             }
         }
+    )
diff --git a/backend-service/app/schemas/user.py b/backend-service/app/schemas/user.py
index 6215db15..b4d988b4 100644
--- a/backend-service/app/schemas/user.py
+++ b/backend-service/app/schemas/user.py
@@ -5,7 +5,7 @@
 from typing import Optional
 from uuid import UUID
 from datetime import datetime
-from pydantic import BaseModel, EmailStr, Field, UUID4
+from pydantic import BaseModel, ConfigDict, EmailStr, Field, UUID4
 
 
 class UserBase(BaseModel):
@@ -63,8 +63,7 @@ class UserResponse(UserBase):
     role_id: Optional[UUID] = None
     role_slug: Optional[str] = None  # Populated from role relationship
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UserInDB(UserResponse):
@@ -93,5 +92,4 @@ class AdminUserListItem(BaseModel):
     created_at: datetime
     last_login: Optional[datetime] = None
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend-service/app/schemas/vocabulary.py b/backend-service/app/schemas/vocabulary.py
index f02912b8..b542f516 100644
--- a/backend-service/app/schemas/vocabulary.py
+++ b/backend-service/app/schemas/vocabulary.py
@@ -56,8 +56,7 @@ class VocabularyItemResponse(VocabularyItemBase):
     created_at: datetime
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ===== UserVocabulary Schemas =====
@@ -114,8 +113,7 @@ class UserVocabularyResponse(BaseModel):
     is_due: bool = Field(default=False, description="Whether review is due")
     accuracy: float = Field(default=0.0, description="Accuracy percentage")
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class UserVocabularyWithItem(UserVocabularyResponse):
@@ -147,10 +145,12 @@ class QuickSaveVocabularyRequest(BaseModel):
     difficulty_level: Optional[str] = Field("A1", max_length=2)
 
     @field_validator("difficulty_level")
+    @classmethod
     def normalize_difficulty_level(cls, v: Optional[str]) -> Optional[str]:
         return v.upper() if isinstance(v, str) else v
 
     @field_validator("part_of_speech")
+    @classmethod
     def normalize_part_of_speech(cls, v: Optional[str]) -> Optional[str]:
         return v.lower() if isinstance(v, str) else v
 
@@ -172,7 +172,8 @@ class ReviewSubmission(BaseModel):
     quality: int = Field(..., ge=0, le=5, description="Quality rating (0-5)")
     time_spent_ms: int = Field(default=0, ge=0, description="Time spent in milliseconds")
     
-    @field_validator('quality')
+    @field_validator("quality")
+    @classmethod
     def validate_quality(cls, v):
         """Ensure quality is in valid range"""
         if not 0 <= v <= 5:
@@ -212,8 +213,7 @@ class VocabularyReviewHistoryItem(BaseModel):
     interval_after: Optional[int]
     reviewed_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 # ===== Due Vocabulary Schemas =====
@@ -262,8 +262,7 @@ class VocabularyDeckResponse(VocabularyDeckBase):
     updated_at: datetime
     item_count: int = Field(default=0, description="Number of items in deck")
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class AddToDeckRequest(BaseModel):
diff --git a/backend-service/app/services/__init__.py b/backend-service/app/services/__init__.py
index ee209389..6bda698f 100644
--- a/backend-service/app/services/__init__.py
+++ b/backend-service/app/services/__init__.py
@@ -1,465 +1,23 @@
-"""
-Achievement Checker Service
-Stateless service to evaluate and unlock achievements based on user actions.
+"""Service package exports.
 
-This service checks achievement conditions and automatically unlocks badges
-when conditions are met. It's designed to be called after specific user actions.
+Heavy service implementations live in dedicated modules. Keep package import
+lightweight so unrelated routes do not load achievement-checking dependencies
+unless they explicitly need them.
 """
 
-from typing import List, Optional, Dict, Any
-from uuid import UUID
-from datetime import datetime, timezone
-import logging
-from sqlalchemy import select, func, and_
-from sqlalchemy.exc import IntegrityError
-from sqlalchemy.ext.asyncio import AsyncSession
-
-from app.models.gamification import Achievement, UserAchievement, ChallengeRewardClaim
-from app.models.progress import UserCourseProgress, LessonCompletion, Streak, DailyActivity
-from app.models.vocabulary import UserVocabulary, VocabularyStatus
-from app.models.user import User
-from app.models.games import GameSession
-
-logger = logging.getLogger(__name__)
-
-
-# Mapping of triggers to achievement condition types
-TRIGGER_CONDITIONS = {
-    "lesson_complete": [
-        "lesson_complete", "xp_earned", "course_complete",
-        "numeric_level", "speed_lesson",
-    ],
-    "streak_update": ["reach_streak", "comeback"],
-    "vocab_review": ["vocab_mastered", "vocab_reviewed"],
-    "quiz_complete": ["perfect_score", "quiz_complete", "first_perfect"],
-    "voice_practice": ["voice_practice"],
-    "xp_earned": ["xp_earned", "numeric_level"],
-    "study_session": ["study_time_night", "study_time_morning"],
-    "grammar_complete": ["grammar_mastered"],
-    "culture_complete": ["culture_lesson"],
-    "writing_complete": ["writing_complete"],
-    "listening_complete": ["listening_complete"],
-    "social_action": ["social_interaction", "help_others"],
-    "chat_complete": ["chat_complete"],
-    "daily_challenge": ["daily_challenge_complete"],
-    "game_complete": [
-        "game_complete",
-        "xp_earned",
-        "numeric_level",
-        "reach_streak",
-    ],
-}
-
-
-class AchievementCheckerService:
-    """
-    Service to check and unlock achievements.
-    
-    Usage:
-        checker = AchievementCheckerService(db)
-        newly_unlocked = await checker.check_by_trigger(user_id, "lesson_complete")
-    """
-    
-    def __init__(self, db: AsyncSession):
-        self.db = db
-    
-    async def check_all(self, user_id: UUID) -> List[Achievement]:
-        """
-        Check all achievements for a user.
-        Returns list of newly unlocked achievements.
-        
-        Use sparingly as this checks ALL conditions.
-        Prefer check_by_trigger() for better performance.
-        """
-        # Get all achievements not yet unlocked by user
-        unlocked_ids = await self._get_unlocked_achievement_ids(user_id)
-        
-        result = await self.db.execute(
-            select(Achievement).where(~Achievement.id.in_(unlocked_ids))
-        )
-        pending_achievements = list(result.scalars().all())
-        
-        # Get user stats once for all evaluations
-        user_stats = await self._get_user_stats(user_id)
-        
-        newly_unlocked = []
-        for achievement in pending_achievements:
-            if await self._evaluate_condition(user_id, achievement, user_stats):
-                unlocked = await self._unlock_achievement(user_id, achievement)
-                if unlocked:
-                    newly_unlocked.append(achievement)
-        
-        return newly_unlocked
-    
-    async def check_by_trigger(self, user_id: UUID, trigger: str) -> List[Achievement]:
-        """
-        Check only achievements related to a specific trigger.
-        More efficient than check_all().
-        
-        Args:
-            user_id: User UUID
-            trigger: One of "lesson_complete", "streak_update", "vocab_review", 
-                     "quiz_complete", "voice_practice", "xp_earned"
-        
-        Returns:
-            List of newly unlocked achievements
-        """
-        condition_types = TRIGGER_CONDITIONS.get(trigger, [])
-        if not condition_types:
-            return []
-        
-        # Get pending achievements of relevant types
-        unlocked_ids = await self._get_unlocked_achievement_ids(user_id)
-        
-        result = await self.db.execute(
-            select(Achievement).where(
-                and_(
-                    ~Achievement.id.in_(unlocked_ids) if unlocked_ids else True,
-                    Achievement.condition_type.in_(condition_types)
-                )
-            )
-        )
-        pending_achievements = list(result.scalars().all())
-        
-        if not pending_achievements:
-            return []
-        
-        # Get only needed stats
-        user_stats = await self._get_user_stats(user_id, condition_types)
-        
-        newly_unlocked = []
-        for achievement in pending_achievements:
-            if await self._evaluate_condition(user_id, achievement, user_stats):
-                unlocked = await self._unlock_achievement(user_id, achievement)
-                if unlocked:
-                    newly_unlocked.append(achievement)
-        
-        return newly_unlocked
-    
-    async def _get_unlocked_achievement_ids(self, user_id: UUID) -> List[UUID]:
-        """Get IDs of achievements already unlocked by user"""
-        result = await self.db.execute(
-            select(UserAchievement.achievement_id).where(
-                UserAchievement.user_id == user_id
-            )
-        )
-        return [row[0] for row in result.all()]
-    
-    async def _get_user_stats(
-        self, 
-        user_id: UUID, 
-        condition_types: Optional[List[str]] = None
-    ) -> Dict[str, Any]:
-        """
-        Fetch user statistics needed for achievement evaluation.
-        Only fetches stats relevant to the condition_types if provided.
-        """
-        stats = {}
-        
-        # Determine which stats to fetch
-        fetch_all = condition_types is None
-        need_lessons = fetch_all or "lesson_complete" in condition_types or "course_complete" in condition_types
-        need_streak = fetch_all or "reach_streak" in condition_types or "comeback" in condition_types
-        need_vocab = fetch_all or "vocab_mastered" in condition_types or "vocab_reviewed" in condition_types
-        need_xp = fetch_all or "xp_earned" in condition_types or "numeric_level" in condition_types
-        need_quiz = fetch_all or "perfect_score" in condition_types or "quiz_complete" in condition_types or "first_perfect" in condition_types
-        need_voice = fetch_all or "voice_practice" in condition_types
-        need_level = fetch_all or "numeric_level" in condition_types
-        need_time = fetch_all or "study_time_night" in condition_types or "study_time_morning" in condition_types or "speed_lesson" in condition_types
-        need_skills = fetch_all or any(ct in (condition_types or []) for ct in ["grammar_mastered", "culture_lesson", "writing_complete", "listening_complete"])
-        need_social = fetch_all or any(ct in (condition_types or []) for ct in ["social_interaction", "chat_complete", "help_others"])
-        need_challenges = fetch_all or "daily_challenge_complete" in condition_types
-        need_games = fetch_all or "game_complete" in condition_types
-        
-        # Fetch lesson completion count
-        if need_lessons:
-            result = await self.db.execute(
-                select(func.count(LessonCompletion.id)).where(
-                    and_(
-                        LessonCompletion.user_id == user_id,
-                        LessonCompletion.is_passed == True
-                    )
-                )
-            )
-            stats["lessons_completed"] = result.scalar() or 0
-            
-            # Count completed courses (progress_percentage >= 100)
-            result = await self.db.execute(
-                select(func.count(UserCourseProgress.id)).where(
-                    and_(
-                        UserCourseProgress.user_id == user_id,
-                        UserCourseProgress.progress_percentage >= 100
-                    )
-                )
-            )
-            stats["courses_completed"] = result.scalar() or 0
-        
-        # Fetch streak from Streak model
-        if need_streak:
-            result = await self.db.execute(
-                select(Streak.current_streak, Streak.longest_streak).where(Streak.user_id == user_id)
-            )
-            row = result.first()
-            if row:
-                stats["current_streak"] = row[0] or 0
-                stats["longest_streak"] = row[1] or 0
-            else:
-                stats["current_streak"] = 0
-                stats["longest_streak"] = 0
-        
-        # Fetch vocabulary mastered
-        if need_vocab:
-            # Count words with status MASTERED
-            result = await self.db.execute(
-                select(func.count(UserVocabulary.id)).where(
-                    and_(
-                        UserVocabulary.user_id == user_id,
-                        UserVocabulary.status == VocabularyStatus.MASTERED
-                    )
-                )
-            )
-            stats["vocab_mastered"] = result.scalar() or 0
-            
-            # Count total reviewed
-            result = await self.db.execute(
-                select(func.count(UserVocabulary.id)).where(
-                    and_(
-                        UserVocabulary.user_id == user_id,
-                        UserVocabulary.total_reviews > 0
-                    )
-                )
-            )
-            stats["vocab_reviewed"] = result.scalar() or 0
-        
-        # Fetch XP (sum from all user course progress)
-        if need_xp:
-            result = await self.db.execute(
-                select(User.total_xp).where(User.id == user_id)
-            )
-            stats["total_xp"] = result.scalar() or 0
+from importlib import import_module
+from typing import Any
 
-        if need_games:
-            result = await self.db.execute(
-                select(func.count(GameSession.id)).where(
-                    and_(
-                        GameSession.user_id == user_id,
-                        GameSession.completed_at.is_not(None),
-                        GameSession.xp_awarded.is_(True),
-                    )
-                )
-            )
-            stats["games_completed"] = result.scalar() or 0
-        
-        # Fetch perfect scores and quiz completions
-        if need_quiz:
-            # Count perfect score lessons (best_score == 100)
-            result = await self.db.execute(
-                select(func.count(LessonCompletion.id)).where(
-                    and_(
-                        LessonCompletion.user_id == user_id,
-                        LessonCompletion.best_score == 100
-                    )
-                )
-            )
-            stats["perfect_scores"] = result.scalar() or 0
-            
-            # Total quiz/lesson completions
-            result = await self.db.execute(
-                select(func.count(LessonCompletion.id)).where(
-                    LessonCompletion.user_id == user_id
-                )
-            )
-            stats["quiz_completed"] = result.scalar() or 0
-        
-        # Fetch voice practice count 
-        # Note: Voice practices not tracked separately yet, return 0 for now
-        if need_voice:
-            stats["voice_practices"] = 0
-        
-        # Fetch numeric level from User model
-        if need_level:
-            result = await self.db.execute(
-                select(User.numeric_level).where(User.id == user_id)
-            )
-            stats["numeric_level"] = result.scalar() or 0
-        
-        # Fetch time-based study stats from DailyActivity
-        if need_time:
-            # Count night study sessions (activities with night hours)
-            # We approximate by counting daily activities — actual hour tracking
-            # would need additional logging. For now count total daily activities.
-            result = await self.db.execute(
-                select(func.count(DailyActivity.id)).where(
-                    DailyActivity.user_id == user_id
-                )
-            )
-            total_activities = result.scalar() or 0
-            stats["night_study_sessions"] = 0  # Placeholder: needs hour tracking
-            stats["morning_study_sessions"] = 0  # Placeholder: needs hour tracking
-            stats["speed_lessons"] = 0  # Placeholder: needs lesson duration tracking
-        
-        # Fetch skill-based stats (grammar, culture, writing, listening)
-        if need_skills:
-            # These are placeholders — actual implementation needs
-            # tagged lesson categories in the database
-            stats["grammar_mastered"] = 0
-            stats["culture_lessons"] = 0
-            stats["writing_completed"] = 0
-            stats["listening_completed"] = 0
-        
-        # Fetch social stats
-        if need_social:
-            stats["social_interactions"] = 0  # Placeholder
-            stats["chats_completed"] = 0  # Placeholder
-            stats["help_others_count"] = 0  # Placeholder
-        
-        # Fetch daily challenge completions
-        if need_challenges:
-            result = await self.db.execute(
-                select(func.count(ChallengeRewardClaim.id)).where(
-                    and_(
-                        ChallengeRewardClaim.user_id == user_id,
-                        ChallengeRewardClaim.challenge_id != "daily_bonus"
-                    )
-                )
-            )
-            stats["daily_challenges_completed"] = result.scalar() or 0
-        
-        return stats
-    
-    async def _evaluate_condition(
-        self, 
-        user_id: UUID, 
-        achievement: Achievement,
-        user_stats: Dict[str, Any]
-    ) -> bool:
-        """
-        Evaluate if user meets the achievement condition.
-        
-        Returns True if condition is met, False otherwise.
-        """
-        condition_type = achievement.condition_type
-        condition_value = achievement.condition_value or 0
-        condition_data = achievement.condition_data or {}
-        
-        # Map condition types to stat checks
-        condition_evaluators = {
-            "lesson_complete": lambda: user_stats.get("lessons_completed", 0) >= condition_value,
-            "reach_streak": lambda: max(
-                user_stats.get("current_streak", 0),
-                user_stats.get("longest_streak", 0)
-            ) >= condition_value,
-            "vocab_mastered": lambda: user_stats.get("vocab_mastered", 0) >= condition_value,
-            "vocab_reviewed": lambda: user_stats.get("vocab_reviewed", 0) >= condition_value,
-            "xp_earned": lambda: user_stats.get("total_xp", 0) >= condition_value,
-            "perfect_score": lambda: user_stats.get("perfect_scores", 0) >= condition_value,
-            "quiz_complete": lambda: user_stats.get("quiz_completed", 0) >= condition_value,
-            "voice_practice": lambda: user_stats.get("voice_practices", 0) >= condition_value,
-            "course_complete": lambda: user_stats.get("courses_completed", 0) >= condition_value,
-            # ---- New condition evaluators ----
-            "numeric_level": lambda: user_stats.get("numeric_level", 0) >= condition_value,
-            "study_time_night": lambda: user_stats.get("night_study_sessions", 0) >= condition_value,
-            "study_time_morning": lambda: user_stats.get("morning_study_sessions", 0) >= condition_value,
-            "speed_lesson": lambda: user_stats.get("speed_lessons", 0) >= condition_value,
-            "first_perfect": lambda: user_stats.get("perfect_scores", 0) >= 1 and condition_value <= 1,
-            "grammar_mastered": lambda: user_stats.get("grammar_mastered", 0) >= condition_value,
-            "culture_lesson": lambda: user_stats.get("culture_lessons", 0) >= condition_value,
-            "writing_complete": lambda: user_stats.get("writing_completed", 0) >= condition_value,
-            "listening_complete": lambda: user_stats.get("listening_completed", 0) >= condition_value,
-            "social_interaction": lambda: user_stats.get("social_interactions", 0) >= condition_value,
-            "chat_complete": lambda: user_stats.get("chats_completed", 0) >= condition_value,
-            "help_others": lambda: user_stats.get("help_others_count", 0) >= condition_value,
-            "daily_challenge_complete": lambda: user_stats.get("daily_challenges_completed", 0) >= condition_value,
-            "game_complete": lambda: user_stats.get("games_completed", 0) >= condition_value,
-            "comeback": lambda: False,  # Special: checked contextually at login
-        }
-        
-        evaluator = condition_evaluators.get(condition_type)
-        if evaluator:
-            return evaluator()
-        
-        # Unknown condition type - log warning and return False
-        logger.warning("Unknown achievement condition type: %s", condition_type)
-        return False
-    
-    async def _unlock_achievement(
-        self, 
-        user_id: UUID, 
-        achievement: Achievement
-    ) -> Optional[UserAchievement]:
-        """
-        Unlock achievement for user (idempotent).
-        Also awards gems if configured.
-        
-        Uses flush + IntegrityError to safely handle race conditions
-        where two concurrent requests try to unlock the same achievement.
-        
-        Returns UserAchievement if newly unlocked, None if already had.
-        """
-        user_achievement: Optional[UserAchievement] = None
-        try:
-            # Isolate insert conflicts without rolling back outer request work.
-            async with self.db.begin_nested():
-                user_achievement = UserAchievement(
-                    user_id=user_id,
-                    achievement_id=achievement.id,
-                    unlocked_at=datetime.now(timezone.utc)
-                )
-                self.db.add(user_achievement)
-                await self.db.flush()
-        except IntegrityError:
-            # Another request already unlocked this — safe to ignore.
-            return None
-        
-        # Award gems (if configured)
-        if achievement.gems_reward > 0:
-            from app.crud.gamification import WalletCRUD
-            await WalletCRUD.add_gems(
-                self.db,
-                user_id,
-                achievement.gems_reward,
-                source="achievement",
-                description=f"Unlocked: {achievement.name}",
-                commit=False,
-            )
-        
-        return user_achievement
+__all__ = [
+    "AchievementCheckerService",
+    "TRIGGER_CONDITIONS",
+    "check_achievements_for_user",
+]
 
 
-# ============================================================================
-# Helper function for easy use in routes
-# ============================================================================
+def __getattr__(name: str) -> Any:
+    if name not in __all__:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
 
-async def check_achievements_for_user(
-    db: AsyncSession,
-    user_id: UUID,
-    trigger: str
-) -> List[Dict[str, Any]]:
-    """
-    Convenience function to check achievements and return serializable results.
-    
-    Args:
-        db: Database session
-        user_id: User UUID
-        trigger: Trigger type (lesson_complete, streak_update, etc.)
-    
-    Returns:
-        List of dicts with unlocked achievement info
-    """
-    checker = AchievementCheckerService(db)
-    unlocked = await checker.check_by_trigger(user_id, trigger)
-    
-    return [
-        {
-            "id": str(a.id),
-            "name": a.name,
-            "description": a.description,
-            "badge_icon": a.badge_icon,
-            "badge_color": a.badge_color,
-            "category": a.category,
-            "rarity": a.rarity,
-            "xp_reward": a.xp_reward,
-            "gems_reward": a.gems_reward,
-        }
-        for a in unlocked
-    ]
+    module = import_module("app.services.achievement_checker_service")
+    return getattr(module, name)
diff --git a/backend-service/app/services/achievement_checker_service.py b/backend-service/app/services/achievement_checker_service.py
new file mode 100644
index 00000000..08094cf7
--- /dev/null
+++ b/backend-service/app/services/achievement_checker_service.py
@@ -0,0 +1,456 @@
+"""
+Achievement Checker Service
+Stateless service to evaluate and unlock achievements based on user actions.
+
+This service checks achievement conditions and automatically unlocks badges
+when conditions are met. It's designed to be called after specific user actions.
+"""
+
+from typing import List, Optional, Dict, Any
+from uuid import UUID
+from datetime import datetime, timezone
+import logging
+from sqlalchemy import select, func, and_
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.gamification import Achievement, UserAchievement, ChallengeRewardClaim
+from app.models.progress import UserCourseProgress, LessonCompletion, Streak, DailyActivity
+from app.models.vocabulary import UserVocabulary, VocabularyStatus
+from app.models.user import User
+from app.models.games import GameSession
+
+logger = logging.getLogger(__name__)
+
+
+# Mapping of triggers to achievement condition types
+TRIGGER_CONDITIONS = {
+    "lesson_complete": [
+        "lesson_complete", "xp_earned", "course_complete",
+        "numeric_level", "speed_lesson",
+    ],
+    "streak_update": ["reach_streak", "comeback"],
+    "vocab_review": ["vocab_mastered", "vocab_reviewed"],
+    "quiz_complete": ["perfect_score", "quiz_complete", "first_perfect"],
+    "voice_practice": ["voice_practice"],
+    "xp_earned": ["xp_earned", "numeric_level"],
+    "study_session": ["study_time_night", "study_time_morning"],
+    "grammar_complete": ["grammar_mastered"],
+    "culture_complete": ["culture_lesson"],
+    "writing_complete": ["writing_complete"],
+    "listening_complete": ["listening_complete"],
+    "social_action": ["social_interaction", "help_others"],
+    "chat_complete": ["chat_complete"],
+    "daily_challenge": ["daily_challenge_complete"],
+    "game_complete": [
+        "game_complete",
+        "xp_earned",
+        "numeric_level",
+        "reach_streak",
+    ],
+}
+
+
+class AchievementCheckerService:
+    """
+    Service to check and unlock achievements.
+
+    Usage:
+        checker = AchievementCheckerService(db)
+        newly_unlocked = await checker.check_by_trigger(user_id, "lesson_complete")
+    """
+
+    def __init__(self, db: AsyncSession):
+        self.db = db
+
+    async def check_all(self, user_id: UUID) -> List[Achievement]:
+        """
+        Check all achievements for a user.
+        Returns list of newly unlocked achievements.
+
+        Use sparingly as this checks ALL conditions.
+        Prefer check_by_trigger() for better performance.
+        """
+        # Get all achievements not yet unlocked by user
+        unlocked_ids = await self._get_unlocked_achievement_ids(user_id)
+
+        result = await self.db.execute(
+            select(Achievement).where(~Achievement.id.in_(unlocked_ids))
+        )
+        pending_achievements = list(result.scalars().all())
+
+        # Get user stats once for all evaluations
+        user_stats = await self._get_user_stats(user_id)
+
+        newly_unlocked = []
+        for achievement in pending_achievements:
+            if await self._evaluate_condition(user_id, achievement, user_stats):
+                unlocked = await self._unlock_achievement(user_id, achievement)
+                if unlocked:
+                    newly_unlocked.append(achievement)
+
+        return newly_unlocked
+
+    async def check_by_trigger(self, user_id: UUID, trigger: str) -> List[Achievement]:
+        """
+        Check only achievements related to a specific trigger.
+        More efficient than check_all().
+
+        Args:
+            user_id: User UUID
+            trigger: One of "lesson_complete", "streak_update", "vocab_review",
+                     "quiz_complete", "voice_practice", "xp_earned"
+
+        Returns:
+            List of newly unlocked achievements
+        """
+        condition_types = TRIGGER_CONDITIONS.get(trigger, [])
+        if not condition_types:
+            return []
+
+        # Get pending achievements of relevant types
+        unlocked_ids = await self._get_unlocked_achievement_ids(user_id)
+
+        result = await self.db.execute(
+            select(Achievement).where(
+                and_(
+                    ~Achievement.id.in_(unlocked_ids) if unlocked_ids else True,
+                    Achievement.condition_type.in_(condition_types)
+                )
+            )
+        )
+        pending_achievements = list(result.scalars().all())
+
+        if not pending_achievements:
+            return []
+
+        # Get only needed stats
+        user_stats = await self._get_user_stats(user_id, condition_types)
+
+        newly_unlocked = []
+        for achievement in pending_achievements:
+            if await self._evaluate_condition(user_id, achievement, user_stats):
+                unlocked = await self._unlock_achievement(user_id, achievement)
+                if unlocked:
+                    newly_unlocked.append(achievement)
+
+        return newly_unlocked
+
+    async def _get_unlocked_achievement_ids(self, user_id: UUID) -> List[UUID]:
+        """Get IDs of achievements already unlocked by user"""
+        result = await self.db.execute(
+            select(UserAchievement.achievement_id).where(
+                UserAchievement.user_id == user_id
+            )
+        )
+        return [row[0] for row in result.all()]
+
+    async def _get_user_stats(
+        self,
+        user_id: UUID,
+        condition_types: Optional[List[str]] = None
+    ) -> Dict[str, Any]:
+        """
+        Fetch user statistics needed for achievement evaluation.
+        Only fetches stats relevant to the condition_types if provided.
+        """
+        stats = {}
+
+        # Determine which stats to fetch
+        fetch_all = condition_types is None
+        need_lessons = fetch_all or "lesson_complete" in condition_types or "course_complete" in condition_types
+        need_streak = fetch_all or "reach_streak" in condition_types or "comeback" in condition_types
+        need_vocab = fetch_all or "vocab_mastered" in condition_types or "vocab_reviewed" in condition_types
+        need_xp = fetch_all or "xp_earned" in condition_types or "numeric_level" in condition_types
+        need_quiz = fetch_all or "perfect_score" in condition_types or "quiz_complete" in condition_types or "first_perfect" in condition_types
+        need_voice = fetch_all or "voice_practice" in condition_types
+        need_level = fetch_all or "numeric_level" in condition_types
+        need_time = fetch_all or "study_time_night" in condition_types or "study_time_morning" in condition_types or "speed_lesson" in condition_types
+        need_skills = fetch_all or any(ct in (condition_types or []) for ct in ["grammar_mastered", "culture_lesson", "writing_complete", "listening_complete"])
+        need_social = fetch_all or any(ct in (condition_types or []) for ct in ["social_interaction", "chat_complete", "help_others"])
+        need_challenges = fetch_all or "daily_challenge_complete" in condition_types
+        need_games = fetch_all or "game_complete" in condition_types
+
+        # Fetch lesson completion count
+        if need_lessons:
+            result = await self.db.execute(
+                select(func.count(LessonCompletion.id)).where(
+                    and_(
+                        LessonCompletion.user_id == user_id,
+                        LessonCompletion.is_passed.is_(True)
+                    )
+                )
+            )
+            stats["lessons_completed"] = result.scalar() or 0
+
+            # Count completed courses (progress_percentage >= 100)
+            result = await self.db.execute(
+                select(func.count(UserCourseProgress.id)).where(
+                    and_(
+                        UserCourseProgress.user_id == user_id,
+                        UserCourseProgress.progress_percentage >= 100
+                    )
+                )
+            )
+            stats["courses_completed"] = result.scalar() or 0
+
+        # Fetch streak from Streak model
+        if need_streak:
+            result = await self.db.execute(
+                select(Streak.current_streak, Streak.longest_streak).where(Streak.user_id == user_id)
+            )
+            row = result.first()
+            if row:
+                stats["current_streak"] = row[0] or 0
+                stats["longest_streak"] = row[1] or 0
+            else:
+                stats["current_streak"] = 0
+                stats["longest_streak"] = 0
+
+        # Fetch vocabulary mastered
+        if need_vocab:
+            # Count words with status MASTERED
+            result = await self.db.execute(
+                select(func.count(UserVocabulary.id)).where(
+                    and_(
+                        UserVocabulary.user_id == user_id,
+                        UserVocabulary.status == VocabularyStatus.MASTERED
+                    )
+                )
+            )
+            stats["vocab_mastered"] = result.scalar() or 0
+
+            # Count total reviewed
+            result = await self.db.execute(
+                select(func.count(UserVocabulary.id)).where(
+                    and_(
+                        UserVocabulary.user_id == user_id,
+                        UserVocabulary.total_reviews > 0
+                    )
+                )
+            )
+            stats["vocab_reviewed"] = result.scalar() or 0
+
+        # Fetch XP (sum from all user course progress)
+        if need_xp:
+            result = await self.db.execute(
+                select(User.total_xp).where(User.id == user_id)
+            )
+            stats["total_xp"] = result.scalar() or 0
+
+        if need_games:
+            result = await self.db.execute(
+                select(func.count(GameSession.id)).where(
+                    and_(
+                        GameSession.user_id == user_id,
+                        GameSession.completed_at.is_not(None),
+                        GameSession.xp_awarded.is_(True),
+                    )
+                )
+            )
+            stats["games_completed"] = result.scalar() or 0
+
+        # Fetch perfect scores and quiz completions
+        if need_quiz:
+            # Count perfect score lessons (best_score == 100)
+            result = await self.db.execute(
+                select(func.count(LessonCompletion.id)).where(
+                    and_(
+                        LessonCompletion.user_id == user_id,
+                        LessonCompletion.best_score == 100
+                    )
+                )
+            )
+            stats["perfect_scores"] = result.scalar() or 0
+
+            # Total quiz/lesson completions
+            result = await self.db.execute(
+                select(func.count(LessonCompletion.id)).where(
+                    LessonCompletion.user_id == user_id
+                )
+            )
+            stats["quiz_completed"] = result.scalar() or 0
+
+        # Fetch voice practice count
+        # Note: Voice practices not tracked separately yet, return 0 for now
+        if need_voice:
+            stats["voice_practices"] = 0
+
+        # Fetch numeric level from User model
+        if need_level:
+            result = await self.db.execute(
+                select(User.numeric_level).where(User.id == user_id)
+            )
+            stats["numeric_level"] = result.scalar() or 0
+
+        # Fetch time-based study stats from DailyActivity
+        if need_time:
+            stats["night_study_sessions"] = 0  # Placeholder: needs hour tracking
+            stats["morning_study_sessions"] = 0  # Placeholder: needs hour tracking
+            stats["speed_lessons"] = 0  # Placeholder: needs lesson duration tracking
+
+        # Fetch skill-based stats (grammar, culture, writing, listening)
+        if need_skills:
+            # These are placeholders — actual implementation needs
+            # tagged lesson categories in the database
+            stats["grammar_mastered"] = 0
+            stats["culture_lessons"] = 0
+            stats["writing_completed"] = 0
+            stats["listening_completed"] = 0
+
+        # Fetch social stats
+        if need_social:
+            stats["social_interactions"] = 0  # Placeholder
+            stats["chats_completed"] = 0  # Placeholder
+            stats["help_others_count"] = 0  # Placeholder
+
+        # Fetch daily challenge completions
+        if need_challenges:
+            result = await self.db.execute(
+                select(func.count(ChallengeRewardClaim.id)).where(
+                    and_(
+                        ChallengeRewardClaim.user_id == user_id,
+                        ChallengeRewardClaim.challenge_id != "daily_bonus"
+                    )
+                )
+            )
+            stats["daily_challenges_completed"] = result.scalar() or 0
+
+        return stats
+
+    async def _evaluate_condition(
+        self,
+        user_id: UUID,
+        achievement: Achievement,
+        user_stats: Dict[str, Any]
+    ) -> bool:
+        """
+        Evaluate if user meets the achievement condition.
+
+        Returns True if condition is met, False otherwise.
+        """
+        condition_type = achievement.condition_type
+        condition_value = achievement.condition_value or 0
+        condition_data = achievement.condition_data or {}
+
+        # Map condition types to stat checks
+        condition_evaluators = {
+            "lesson_complete": lambda: user_stats.get("lessons_completed", 0) >= condition_value,
+            "reach_streak": lambda: max(
+                user_stats.get("current_streak", 0),
+                user_stats.get("longest_streak", 0)
+            ) >= condition_value,
+            "vocab_mastered": lambda: user_stats.get("vocab_mastered", 0) >= condition_value,
+            "vocab_reviewed": lambda: user_stats.get("vocab_reviewed", 0) >= condition_value,
+            "xp_earned": lambda: user_stats.get("total_xp", 0) >= condition_value,
+            "perfect_score": lambda: user_stats.get("perfect_scores", 0) >= condition_value,
+            "quiz_complete": lambda: user_stats.get("quiz_completed", 0) >= condition_value,
+            "voice_practice": lambda: user_stats.get("voice_practices", 0) >= condition_value,
+            "course_complete": lambda: user_stats.get("courses_completed", 0) >= condition_value,
+            # ---- New condition evaluators ----
+            "numeric_level": lambda: user_stats.get("numeric_level", 0) >= condition_value,
+            "study_time_night": lambda: user_stats.get("night_study_sessions", 0) >= condition_value,
+            "study_time_morning": lambda: user_stats.get("morning_study_sessions", 0) >= condition_value,
+            "speed_lesson": lambda: user_stats.get("speed_lessons", 0) >= condition_value,
+            "first_perfect": lambda: user_stats.get("perfect_scores", 0) >= 1 and condition_value <= 1,
+            "grammar_mastered": lambda: user_stats.get("grammar_mastered", 0) >= condition_value,
+            "culture_lesson": lambda: user_stats.get("culture_lessons", 0) >= condition_value,
+            "writing_complete": lambda: user_stats.get("writing_completed", 0) >= condition_value,
+            "listening_complete": lambda: user_stats.get("listening_completed", 0) >= condition_value,
+            "social_interaction": lambda: user_stats.get("social_interactions", 0) >= condition_value,
+            "chat_complete": lambda: user_stats.get("chats_completed", 0) >= condition_value,
+            "help_others": lambda: user_stats.get("help_others_count", 0) >= condition_value,
+            "daily_challenge_complete": lambda: user_stats.get("daily_challenges_completed", 0) >= condition_value,
+            "game_complete": lambda: user_stats.get("games_completed", 0) >= condition_value,
+            "comeback": lambda: False,  # Special: checked contextually at login
+        }
+
+        evaluator = condition_evaluators.get(condition_type)
+        if evaluator:
+            return evaluator()
+
+        # Unknown condition type - log warning and return False
+        logger.warning("Unknown achievement condition type: %s", condition_type)
+        return False
+
+    async def _unlock_achievement(
+        self,
+        user_id: UUID,
+        achievement: Achievement
+    ) -> Optional[UserAchievement]:
+        """
+        Unlock achievement for user (idempotent).
+        Also awards gems if configured.
+
+        Uses flush + IntegrityError to safely handle race conditions
+        where two concurrent requests try to unlock the same achievement.
+
+        Returns UserAchievement if newly unlocked, None if already had.
+        """
+        user_achievement: Optional[UserAchievement] = None
+        try:
+            # Isolate insert conflicts without rolling back outer request work.
+            async with self.db.begin_nested():
+                user_achievement = UserAchievement(
+                    user_id=user_id,
+                    achievement_id=achievement.id,
+                    unlocked_at=datetime.now(timezone.utc)
+                )
+                self.db.add(user_achievement)
+                await self.db.flush()
+        except IntegrityError:
+            # Another request already unlocked this — safe to ignore.
+            return None
+
+        # Award gems (if configured)
+        if achievement.gems_reward > 0:
+            from app.crud.gamification import WalletCRUD
+            await WalletCRUD.add_gems(
+                self.db,
+                user_id,
+                achievement.gems_reward,
+                source="achievement",
+                description=f"Unlocked: {achievement.name}",
+                commit=False,
+            )
+
+        return user_achievement
+
+
+# ============================================================================
+# Helper function for easy use in routes
+# ============================================================================
+
+async def check_achievements_for_user(
+    db: AsyncSession,
+    user_id: UUID,
+    trigger: str
+) -> List[Dict[str, Any]]:
+    """
+    Convenience function to check achievements and return serializable results.
+
+    Args:
+        db: Database session
+        user_id: User UUID
+        trigger: Trigger type (lesson_complete, streak_update, etc.)
+
+    Returns:
+        List of dicts with unlocked achievement info
+    """
+    checker = AchievementCheckerService(db)
+    unlocked = await checker.check_by_trigger(user_id, trigger)
+
+    return [
+        {
+            "id": str(a.id),
+            "name": a.name,
+            "description": a.description,
+            "badge_icon": a.badge_icon,
+            "badge_color": a.badge_color,
+            "category": a.category,
+            "rarity": a.rarity,
+            "xp_reward": a.xp_reward,
+            "gems_reward": a.gems_reward,
+        }
+        for a in unlocked
+    ]
diff --git a/backend-service/app/services/admin_seed_service.py b/backend-service/app/services/admin_seed_service.py
new file mode 100644
index 00000000..c5490a3c
--- /dev/null
+++ b/backend-service/app/services/admin_seed_service.py
@@ -0,0 +1,121 @@
+"""Seeding logic for the dev-only /admin/seed endpoint, split by data type."""
+
+import copy
+from uuid import UUID
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.sample_data_catalog import (
+    SAMPLE_ACHIEVEMENTS,
+    SAMPLE_COURSE_CATEGORIES,
+    SAMPLE_COURSES,
+)
+from app.core.shop_catalog import SHOP_CATALOG
+from app.models.course import Course, Lesson, Unit
+from app.models.course_category import CourseCategory
+from app.models.gamification import Achievement, ShopItem
+
+
+async def seed_achievements(db: AsyncSession) -> int:
+    created = 0
+    for ach_data in SAMPLE_ACHIEVEMENTS:
+        result = await db.execute(
+            select(Achievement).where(Achievement.name == ach_data["name"])
+        )
+        if not result.scalar_one_or_none():
+            db.add(Achievement(**ach_data))
+            created += 1
+    return created
+
+
+async def seed_shop_items(db: AsyncSession) -> int:
+    created = 0
+    for item_data in SHOP_CATALOG:
+        result = await db.execute(
+            select(ShopItem).where(ShopItem.name == item_data["name"])
+        )
+        existing_item = result.scalar_one_or_none()
+        if not existing_item:
+            db.add(ShopItem(**item_data))
+            created += 1
+        else:
+            for field, value in item_data.items():
+                setattr(existing_item, field, value)
+    return created
+
+
+async def seed_course_categories(db: AsyncSession) -> tuple[int, dict[str, UUID]]:
+    created = 0
+    category_ids: dict[str, UUID] = {}
+    for category_data in SAMPLE_COURSE_CATEGORIES:
+        result = await db.execute(
+            select(CourseCategory).where(CourseCategory.slug == category_data["slug"])
+        )
+        category = result.scalar_one_or_none()
+        if not category:
+            category = CourseCategory(**category_data)
+            db.add(category)
+            await db.flush()
+            created += 1
+        category_ids[category_data["slug"]] = category.id
+    return created, category_ids
+
+
+async def seed_courses(
+    db: AsyncSession, category_ids: dict[str, UUID]
+) -> tuple[int, int, int]:
+    """Returns (courses_created, units_created, lessons_created)."""
+    courses_created = 0
+    units_created = 0
+    lessons_created = 0
+
+    # SAMPLE_COURSES is a module-level constant mutated in place below
+    # (.pop on units/exercises) — deep-copy so repeated calls stay idempotent.
+    for course_data in copy.deepcopy(SAMPLE_COURSES):
+        result = await db.execute(
+            select(Course).where(Course.title == course_data["title"])
+        )
+        existing_course = result.scalar_one_or_none()
+        if existing_course:
+            await db.delete(existing_course)
+            await db.flush()
+
+        unit_seed = course_data.pop("units")
+        category_slug = course_data.pop("category_slug")
+
+        course = Course(
+            **course_data,
+            category_id=category_ids.get(category_slug),
+            total_lessons=sum(len(unit["lessons"]) for unit in unit_seed),
+            is_published=True,
+        )
+        db.add(course)
+        await db.flush()
+        courses_created += 1
+
+        for unit_data in unit_seed:
+            lesson_seed = unit_data.pop("lessons")
+            unit = Unit(
+                **unit_data,
+                course_id=course.id,
+                total_lessons=len(lesson_seed),
+            )
+            db.add(unit)
+            await db.flush()
+            units_created += 1
+
+            for lesson_data in lesson_seed:
+                exercises = lesson_data.pop("exercises", [])
+                lesson = Lesson(
+                    **lesson_data,
+                    course_id=course.id,
+                    unit_id=unit.id,
+                    content={"exercises": exercises, "version": 1},
+                    pass_threshold=70,
+                    lesson_type="lesson",
+                )
+                db.add(lesson)
+                lessons_created += 1
+
+    return courses_created, units_created, lessons_created
diff --git a/backend-service/app/services/api_cache_service.py b/backend-service/app/services/api_cache_service.py
index a4024a0c..c26d7dae 100644
--- a/backend-service/app/services/api_cache_service.py
+++ b/backend-service/app/services/api_cache_service.py
@@ -84,6 +84,7 @@ async def get_or_fetch(
         api_name: str,
         fetch_fn: Callable,
         priority: Priority = Priority.MEDIUM,
+        cost: int = 1,
         redis_ttl: int = 3600,
         db_ttl: int = 86400,
     ) -> CacheResult:
@@ -95,6 +96,7 @@ async def get_or_fetch(
             api_name: API identifier for quota tracking (e.g. "newsapi")
             fetch_fn: Async callable that fetches from external API
             priority: Request priority level (affects quota threshold behavior)
+            cost: Quota units consumed by a cache miss; 0 bypasses quota checks
             redis_ttl: Redis cache time-to-live in seconds
             db_ttl: PostgreSQL "freshness" TTL in seconds
             
@@ -136,48 +138,50 @@ async def get_or_fetch(
                 is_stale=False,
             )
         
-        # ──── Layer 3: Check quota threshold BEFORE calling external API ────
-        quota_status = await QuotaManager.check_status(api_name)
-        
-        # BLOCKED (100%+): NEVER call API
-        if quota_status == QuotaStatus.BLOCKED:
-            logger.warning(f"Quota BLOCKED for {api_name}, serving stale cache")
-            if db_entry is not None:
-                return CacheResult(
-                    data=json.loads(db_entry.data),
-                    source="db_stale",
-                    is_stale=True,
-                )
-            raise QuotaExhaustedError(api_name, QuotaManager.get_reset_time())
-        
-        # CRITICAL (90-99%): only HIGH priority gets through
-        if quota_status == QuotaStatus.CRITICAL and priority != Priority.HIGH:
-            logger.info(
-                f"Quota CRITICAL for {api_name}, blocking {priority.value} priority"
-            )
-            if db_entry is not None:
-                return CacheResult(
-                    data=json.loads(db_entry.data),
-                    source="db_stale",
-                    is_stale=True,
+        if cost > 0:
+            # ──── Layer 3: Check quota threshold BEFORE calling external API ────
+            quota_status = await QuotaManager.check_status(api_name, cost=cost)
+
+            # BLOCKED (100%+): NEVER call API
+            if quota_status == QuotaStatus.BLOCKED:
+                logger.warning("Quota BLOCKED for %s, serving stale cache", api_name)
+                if db_entry is not None:
+                    return CacheResult(
+                        data=json.loads(db_entry.data),
+                        source="db_stale",
+                        is_stale=True,
+                    )
+                raise QuotaExhaustedError(api_name, QuotaManager.get_reset_time())
+
+            # CRITICAL (90-99%): only HIGH priority gets through
+            if quota_status == QuotaStatus.CRITICAL and priority != Priority.HIGH:
+                logger.info(
+                    "Quota CRITICAL for %s, blocking %s priority",
+                    api_name,
+                    priority.value,
                 )
-            raise QuotaNearLimitError(
-                api_name, "CRITICAL",
-                "Only user-initiated requests allowed at this quota level."
-            )
-        
-        # WARNING (70-89%): block LOW priority (background/prefetch)
-        if quota_status == QuotaStatus.WARNING and priority == Priority.LOW:
-            logger.info(
-                f"Quota WARNING for {api_name}, blocking LOW priority"
-            )
-            if db_entry is not None:
-                return CacheResult(
-                    data=json.loads(db_entry.data),
-                    source="db_stale",
-                    is_stale=True,
+                if db_entry is not None:
+                    return CacheResult(
+                        data=json.loads(db_entry.data),
+                        source="db_stale",
+                        is_stale=True,
+                    )
+                raise QuotaNearLimitError(
+                    api_name,
+                    "CRITICAL",
+                    "Only user-initiated requests allowed at this quota level.",
                 )
-            # No cache at all → allow even LOW (user should see something)
+
+            # WARNING (70-89%): block LOW priority (background/prefetch)
+            if quota_status == QuotaStatus.WARNING and priority == Priority.LOW:
+                logger.info("Quota WARNING for %s, blocking LOW priority", api_name)
+                if db_entry is not None:
+                    return CacheResult(
+                        data=json.loads(db_entry.data),
+                        source="db_stale",
+                        is_stale=True,
+                    )
+                # No cache at all → allow even LOW (user should see something)
         
         # ──── Layer 3: Fetch from external API ────
         try:
@@ -195,8 +199,9 @@ async def get_or_fetch(
                 )
             raise
         
-        # Record quota usage
-        await QuotaManager.record_request(api_name)
+        # Record quota usage only for calls that consume upstream quota.
+        if cost > 0:
+            await QuotaManager.record_request(api_name, cost=cost)
         
         # ──── Store in both cache layers ────
         data_json = json.dumps(result, ensure_ascii=False, default=str)
diff --git a/backend-service/app/services/content_agent_artifact_index.py b/backend-service/app/services/content_agent_artifact_index.py
new file mode 100644
index 00000000..d5580a7a
--- /dev/null
+++ b/backend-service/app/services/content_agent_artifact_index.py
@@ -0,0 +1,250 @@
+"""Typed traversal index for raw content-agent artifacts.
+
+The validation service receives raw dictionaries from jobs, uploads, and AI
+responses.  This module centralizes the defensive walk over the nested
+course/unit/lesson tree so validation rules can work with dict-only nodes.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Any
+
+
+@dataclass(frozen=True)
+class StructuralIssue:
+    code: str
+    path: str
+    message: str
+
+
+@dataclass(frozen=True)
+class ObjectNode:
+    path: str
+    data: dict[str, Any]
+
+
+@dataclass(frozen=True)
+class LessonNode:
+    path: str
+    data: dict[str, Any]
+    vocabulary: tuple[ObjectNode, ...]
+    exercises: tuple[ObjectNode, ...]
+
+
+@dataclass(frozen=True)
+class UnitNode:
+    path: str
+    data: dict[str, Any]
+    lessons: tuple[LessonNode, ...]
+
+
+@dataclass(frozen=True)
+class CourseNode:
+    path: str
+    data: dict[str, Any]
+    units: tuple[UnitNode, ...]
+
+
+@dataclass(frozen=True)
+class ArtifactIndex:
+    courses: tuple[CourseNode, ...]
+    units: tuple[UnitNode, ...]
+    lessons: tuple[LessonNode, ...]
+    vocabulary: tuple[ObjectNode, ...]
+    exercises: tuple[ObjectNode, ...]
+    structural_errors: tuple[StructuralIssue, ...] = field(default_factory=tuple)
+
+
+def _add_issue(
+    issues: list[StructuralIssue], code: str, path: str, message: str
+) -> None:
+    issues.append(StructuralIssue(code=code, path=path, message=message))
+
+
+def _list_field(
+    owner: dict[str, Any],
+    field_name: str,
+    path: str,
+    issues: list[StructuralIssue],
+    type_code: str,
+) -> list[Any]:
+    value = owner.get(field_name)
+    if value is None:
+        return []
+    if not isinstance(value, list):
+        _add_issue(issues, type_code, path, f"{field_name} must be a list")
+        return []
+    return value
+
+
+def _object_node(
+    value: Any,
+    path: str,
+    issues: list[StructuralIssue],
+    code: str,
+    label: str,
+) -> dict[str, Any] | None:
+    if isinstance(value, dict):
+        return value
+    _add_issue(issues, code, path, f"{label} must be an object")
+    return None
+
+
+def build_artifact_index(artifact: dict[str, Any]) -> ArtifactIndex:
+    issues: list[StructuralIssue] = []
+    courses_raw = artifact.get("courses")
+    if courses_raw is None:
+        courses_raw = []
+    elif not isinstance(courses_raw, list):
+        _add_issue(issues, "COURSES_TYPE", "courses", "courses must be a list")
+        courses_raw = []
+
+    courses: list[CourseNode] = []
+    all_units: list[UnitNode] = []
+    all_lessons: list[LessonNode] = []
+    all_vocabulary: list[ObjectNode] = []
+    all_exercises: list[ObjectNode] = []
+
+    for ci, course_value in enumerate(courses_raw):
+        course_path = f"courses[{ci}]"
+        course = _object_node(
+            course_value,
+            course_path,
+            issues,
+            "COURSE_ENTRY_TYPE",
+            "course entry",
+        )
+        if course is None:
+            continue
+
+        units_raw = _list_field(
+            course,
+            "units",
+            f"{course_path}.units",
+            issues,
+            "UNITS_TYPE",
+        )
+        if not units_raw:
+            _add_issue(
+                issues,
+                "NO_UNITS",
+                f"{course_path}.units",
+                "course must contain at least one unit",
+            )
+
+        unit_nodes: list[UnitNode] = []
+        for ui, unit_value in enumerate(units_raw):
+            unit_path = f"{course_path}.units[{ui}]"
+            unit = _object_node(
+                unit_value,
+                unit_path,
+                issues,
+                "UNIT_ENTRY_TYPE",
+                "unit entry",
+            )
+            if unit is None:
+                continue
+
+            lessons_raw = _list_field(
+                unit,
+                "lessons",
+                f"{unit_path}.lessons",
+                issues,
+                "LESSONS_TYPE",
+            )
+            if not lessons_raw:
+                _add_issue(
+                    issues,
+                    "NO_LESSONS",
+                    f"{unit_path}.lessons",
+                    "unit must contain at least one lesson",
+                )
+
+            lesson_nodes: list[LessonNode] = []
+            for li, lesson_value in enumerate(lessons_raw):
+                lesson_path = f"{unit_path}.lessons[{li}]"
+                lesson = _object_node(
+                    lesson_value,
+                    lesson_path,
+                    issues,
+                    "LESSON_ENTRY_TYPE",
+                    "lesson entry",
+                )
+                if lesson is None:
+                    continue
+
+                vocabulary_raw = _list_field(
+                    lesson,
+                    "vocabulary",
+                    f"{lesson_path}.vocabulary",
+                    issues,
+                    "VOCABULARY_TYPE",
+                )
+                vocabulary_nodes: list[ObjectNode] = []
+                for vi, vocab_value in enumerate(vocabulary_raw):
+                    vocab_path = f"{lesson_path}.vocabulary[{vi}]"
+                    vocab = _object_node(
+                        vocab_value,
+                        vocab_path,
+                        issues,
+                        "VOCABULARY_ENTRY_TYPE",
+                        "vocabulary entry",
+                    )
+                    if vocab is not None:
+                        vocabulary_nodes.append(ObjectNode(vocab_path, vocab))
+
+                exercises_raw = _list_field(
+                    lesson,
+                    "exercises",
+                    f"{lesson_path}.exercises",
+                    issues,
+                    "EXERCISES_TYPE",
+                )
+                exercise_nodes: list[ObjectNode] = []
+                for ei, exercise_value in enumerate(exercises_raw):
+                    exercise_path = f"{lesson_path}.exercises[{ei}]"
+                    exercise = _object_node(
+                        exercise_value,
+                        exercise_path,
+                        issues,
+                        "EXERCISE_ENTRY_TYPE",
+                        "exercise entry",
+                    )
+                    if exercise is not None:
+                        exercise_nodes.append(ObjectNode(exercise_path, exercise))
+
+                lesson_node = LessonNode(
+                    path=lesson_path,
+                    data=lesson,
+                    vocabulary=tuple(vocabulary_nodes),
+                    exercises=tuple(exercise_nodes),
+                )
+                lesson_nodes.append(lesson_node)
+                all_vocabulary.extend(vocabulary_nodes)
+                all_exercises.extend(exercise_nodes)
+
+            unit_node = UnitNode(
+                path=unit_path,
+                data=unit,
+                lessons=tuple(lesson_nodes),
+            )
+            unit_nodes.append(unit_node)
+            all_lessons.extend(lesson_nodes)
+
+        course_node = CourseNode(
+            path=course_path,
+            data=course,
+            units=tuple(unit_nodes),
+        )
+        courses.append(course_node)
+        all_units.extend(unit_nodes)
+
+    return ArtifactIndex(
+        courses=tuple(courses),
+        units=tuple(all_units),
+        lessons=tuple(all_lessons),
+        vocabulary=tuple(all_vocabulary),
+        exercises=tuple(all_exercises),
+        structural_errors=tuple(issues),
+    )
diff --git a/backend-service/app/services/content_agent_validation.py b/backend-service/app/services/content_agent_validation.py
index 7d5c3fa1..582ae69e 100644
--- a/backend-service/app/services/content_agent_validation.py
+++ b/backend-service/app/services/content_agent_validation.py
@@ -14,6 +14,11 @@
 from pathlib import Path
 from typing import Any
 
+from app.services.content_agent_artifact_index import (
+    ArtifactIndex,
+    build_artifact_index,
+)
+
 # ---------------------------------------------------------------------------
 # Valid enum sets (mirrors the Pydantic schema without importing it to keep
 # this module importable before the ORM is initialised)
@@ -328,8 +333,8 @@ def _check_manifest_coverage(
 
 
 def _check_courses_present(artifact: dict[str, Any], report: ValidationReport) -> None:
-    courses = artifact.get("courses") or []
-    if not courses:
+    courses = artifact.get("courses")
+    if courses is None or courses == []:
         _blocking(
             report,
             "NO_COURSES",
@@ -340,6 +345,7 @@ def _check_courses_present(artifact: dict[str, Any], report: ValidationReport) -
 
 def _check_provenance(
     artifact: dict[str, Any],
+    index: ArtifactIndex,
     report: ValidationReport,
     pinned_snapshots: list[dict[str, Any]],
 ) -> None:
@@ -353,470 +359,404 @@ def _check_provenance(
         str(pin.get("source_name") or pin.get("source_id")): pin
         for pin in pinned_snapshots
     }
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for vi, vocab in enumerate(lesson.get("vocabulary") or []):
-                    base = (
-                        f"courses[{ci}].units[{ui}].lessons[{li}]"
-                        f".vocabulary[{vi}]"
+    for vocab_node in index.vocabulary:
+        vocab = vocab_node.data
+        base = vocab_node.path
+        mode = vocab.get("license_mode", "")
+        if mode not in _LICENSE_MODES:
+            _blocking(
+                report,
+                "INVALID_LICENSE_MODE",
+                f"{base}.license_mode",
+                f"license_mode '{mode}' is not storable",
+            )
+        source_name = str(vocab.get("source_name") or "")
+        if source_name == "generated":
+            if mode != "generated":
+                _blocking(
+                    report,
+                    "GENERATED_LICENSE_MODE_INVALID",
+                    f"{base}.license_mode",
+                    "generated vocabulary must use license_mode 'generated'",
+                )
+            for field_name in (
+                "source_url",
+                "source_checksum",
+                "source_version",
+                "source_record_id",
+                "license_id",
+                "license_url",
+                "attribution_text",
+                "raw_checksum",
+                "record_checksum",
+                "lineage",
+                "content_usage",
+            ):
+                if vocab.get(field_name) not in (None, "", {}):
+                    _blocking(
+                        report,
+                        "GENERATED_PROVENANCE_PRESENT",
+                        f"{base}.{field_name}",
+                        "generated vocabulary must not carry imported "
+                        "source provenance",
                     )
-                    mode = vocab.get("license_mode", "")
-                    if mode not in _LICENSE_MODES:
-                        _blocking(
-                            report,
-                            "INVALID_LICENSE_MODE",
-                            f"{base}.license_mode",
-                            f"license_mode '{mode}' is not storable",
-                        )
-                    source_name = str(vocab.get("source_name") or "")
-                    if source_name == "generated":
-                        if mode != "generated":
-                            _blocking(
-                                report,
-                                "GENERATED_LICENSE_MODE_INVALID",
-                                f"{base}.license_mode",
-                                "generated vocabulary must use license_mode 'generated'",
-                            )
-                        for field_name in (
-                            "source_url",
-                            "source_checksum",
-                            "source_version",
-                            "source_record_id",
-                            "license_id",
-                            "license_url",
-                            "attribution_text",
-                            "raw_checksum",
-                            "record_checksum",
-                            "lineage",
-                            "content_usage",
-                        ):
-                            if vocab.get(field_name) not in (None, "", {}):
-                                _blocking(
-                                    report,
-                                    "GENERATED_PROVENANCE_PRESENT",
-                                    f"{base}.{field_name}",
-                                    "generated vocabulary must not carry imported "
-                                    "source provenance",
-                                )
-                        continue
-                    manifest = manifest_by_source.get(source_name)
-                    if manifest is None:
-                        _blocking(
-                            report,
-                            "VOCAB_SOURCE_NOT_IN_MANIFEST",
-                            f"{base}.source_name",
-                            f"source '{source_name}' is absent from source_manifest",
-                        )
-                        continue
-                    pin = pinned_by_source.get(source_name)
-                    if source_name == "admin_upload":
-                        required_fields = (
-                            "source_record_id",
-                            "record_checksum",
-                            "lineage",
-                            "content_usage",
-                            "source_version",
-                            "license_id",
-                            "license_url",
-                            "attribution_text",
-                            "raw_checksum",
-                        )
-                        for field_name in required_fields:
-                            if vocab.get(field_name) in (None, "", {}):
-                                _blocking(
-                                    report,
-                                    "VOCAB_PROVENANCE_MISSING",
-                                    f"{base}.{field_name}",
-                                    f"{field_name} is required for admin upload content",
-                                )
-                        if mode != "admin_owned":
-                            _blocking(
-                                report,
-                                "ADMIN_UPLOAD_LICENSE_MODE_INVALID",
-                                f"{base}.license_mode",
-                                "admin_upload vocabulary must use admin_owned mode",
-                            )
-                        for field_name in (
-                            "source_version",
-                            "license_id",
-                            "license_url",
-                            "attribution_text",
-                            "raw_checksum",
-                        ):
-                            if str(vocab.get(field_name)) != str(
-                                manifest.get(field_name)
-                            ):
-                                _blocking(
-                                    report,
-                                    "VOCAB_PROVENANCE_MISMATCH",
-                                    f"{base}.{field_name}",
-                                    f"{field_name} does not match the admin upload manifest",
-                                )
-                        if not _SHA256_PATTERN.fullmatch(
-                            str(vocab.get("record_checksum") or "")
-                        ):
-                            _blocking(
-                                report,
-                                "VOCAB_RECORD_CHECKSUM_INVALID",
-                                f"{base}.record_checksum",
-                                "record_checksum must be a lowercase SHA-256 digest",
-                            )
-                        lineage = vocab.get("lineage")
-                        if not isinstance(lineage, dict) or not {
-                            "adapter",
-                            "adapter_version",
-                            "raw_path",
-                        }.issubset(lineage):
-                            _blocking(
-                                report,
-                                "VOCAB_LINEAGE_INVALID",
-                                f"{base}.lineage",
-                                "lineage must identify adapter, adapter_version, and raw_path",
-                            )
-                        continue
-                    if pin is None:
-                        _blocking(
-                            report,
-                            "VOCAB_SOURCE_NOT_PINNED",
-                            f"{base}.source_name",
-                            f"dataset source '{source_name}' was not pinned to the job",
-                        )
-                        continue
-                    required_fields = (
-                        "source_url",
-                        "source_record_id",
-                        "record_checksum",
-                        "lineage",
-                        "content_usage",
-                        *_PINNED_PROVENANCE_FIELDS,
+            continue
+        manifest = manifest_by_source.get(source_name)
+        if manifest is None:
+            _blocking(
+                report,
+                "VOCAB_SOURCE_NOT_IN_MANIFEST",
+                f"{base}.source_name",
+                f"source '{source_name}' is absent from source_manifest",
+            )
+            continue
+        pin = pinned_by_source.get(source_name)
+        if source_name == "admin_upload":
+            required_fields = (
+                "source_record_id",
+                "record_checksum",
+                "lineage",
+                "content_usage",
+                "source_version",
+                "license_id",
+                "license_url",
+                "attribution_text",
+                "raw_checksum",
+            )
+            for field_name in required_fields:
+                if vocab.get(field_name) in (None, "", {}):
+                    _blocking(
+                        report,
+                        "VOCAB_PROVENANCE_MISSING",
+                        f"{base}.{field_name}",
+                        f"{field_name} is required for admin upload content",
+                    )
+            if mode != "admin_owned":
+                _blocking(
+                    report,
+                    "ADMIN_UPLOAD_LICENSE_MODE_INVALID",
+                    f"{base}.license_mode",
+                    "admin_upload vocabulary must use admin_owned mode",
+                )
+            for field_name in (
+                "source_version",
+                "license_id",
+                "license_url",
+                "attribution_text",
+                "raw_checksum",
+            ):
+                if str(vocab.get(field_name)) != str(manifest.get(field_name)):
+                    _blocking(
+                        report,
+                        "VOCAB_PROVENANCE_MISMATCH",
+                        f"{base}.{field_name}",
+                        f"{field_name} does not match the admin upload manifest",
                     )
-                    for field_name in required_fields:
-                        if vocab.get(field_name) in (None, "", {}):
-                            _blocking(
-                                report,
-                                "VOCAB_PROVENANCE_MISSING",
-                                f"{base}.{field_name}",
-                                f"{field_name} is required for pinned dataset content",
-                            )
-                    if not _is_valid_url(str(vocab.get("source_url") or "")):
-                        _blocking(
-                            report,
-                            "INVALID_SOURCE_URL",
-                            f"{base}.source_url",
-                            "source_url must be a valid http/https URL",
-                        )
-                    if not _SHA256_PATTERN.fullmatch(
-                        str(vocab.get("record_checksum") or "")
-                    ):
-                        _blocking(
-                            report,
-                            "VOCAB_RECORD_CHECKSUM_INVALID",
-                            f"{base}.record_checksum",
-                            "record_checksum must be a lowercase SHA-256 digest",
-                        )
-                    lineage = vocab.get("lineage")
-                    if not isinstance(lineage, dict) or not {
-                        "adapter",
-                        "adapter_version",
-                        "raw_path",
-                    }.issubset(lineage):
-                        _blocking(
-                            report,
-                            "VOCAB_LINEAGE_INVALID",
-                            f"{base}.lineage",
-                            "lineage must identify adapter, adapter_version, and raw_path",
-                        )
-                    for field_name in _PINNED_PROVENANCE_FIELDS:
-                        if str(vocab.get(field_name)) != str(pin.get(field_name)):
-                            _blocking(
-                                report,
-                                "VOCAB_PROVENANCE_MISMATCH",
-                                f"{base}.{field_name}",
-                                f"{field_name} does not match the pinned snapshot",
-                            )
-
-
-def _check_course_levels(artifact: dict[str, Any], report: ValidationReport) -> None:
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        level = course.get("level", "")
+            if not _SHA256_PATTERN.fullmatch(
+                str(vocab.get("record_checksum") or "")
+            ):
+                _blocking(
+                    report,
+                    "VOCAB_RECORD_CHECKSUM_INVALID",
+                    f"{base}.record_checksum",
+                    "record_checksum must be a lowercase SHA-256 digest",
+                )
+            lineage = vocab.get("lineage")
+            if not isinstance(lineage, dict) or not {
+                "adapter",
+                "adapter_version",
+                "raw_path",
+            }.issubset(lineage):
+                _blocking(
+                    report,
+                    "VOCAB_LINEAGE_INVALID",
+                    f"{base}.lineage",
+                    "lineage must identify adapter, adapter_version, and raw_path",
+                )
+            continue
+        if pin is None:
+            _blocking(
+                report,
+                "VOCAB_SOURCE_NOT_PINNED",
+                f"{base}.source_name",
+                f"dataset source '{source_name}' was not pinned to the job",
+            )
+            continue
+        required_fields = (
+            "source_url",
+            "source_record_id",
+            "record_checksum",
+            "lineage",
+            "content_usage",
+            *_PINNED_PROVENANCE_FIELDS,
+        )
+        for field_name in required_fields:
+            if vocab.get(field_name) in (None, "", {}):
+                _blocking(
+                    report,
+                    "VOCAB_PROVENANCE_MISSING",
+                    f"{base}.{field_name}",
+                    f"{field_name} is required for pinned dataset content",
+                )
+        if not _is_valid_url(str(vocab.get("source_url") or "")):
+            _blocking(
+                report,
+                "INVALID_SOURCE_URL",
+                f"{base}.source_url",
+                "source_url must be a valid http/https URL",
+            )
+        if not _SHA256_PATTERN.fullmatch(str(vocab.get("record_checksum") or "")):
+            _blocking(
+                report,
+                "VOCAB_RECORD_CHECKSUM_INVALID",
+                f"{base}.record_checksum",
+                "record_checksum must be a lowercase SHA-256 digest",
+            )
+        lineage = vocab.get("lineage")
+        if not isinstance(lineage, dict) or not {
+            "adapter",
+            "adapter_version",
+            "raw_path",
+        }.issubset(lineage):
+            _blocking(
+                report,
+                "VOCAB_LINEAGE_INVALID",
+                f"{base}.lineage",
+                "lineage must identify adapter, adapter_version, and raw_path",
+            )
+        for field_name in _PINNED_PROVENANCE_FIELDS:
+            if str(vocab.get(field_name)) != str(pin.get(field_name)):
+                _blocking(
+                    report,
+                    "VOCAB_PROVENANCE_MISMATCH",
+                    f"{base}.{field_name}",
+                    f"{field_name} does not match the pinned snapshot",
+                )
+
+
+def _check_course_levels(index: ArtifactIndex, report: ValidationReport) -> None:
+    for course_node in index.courses:
+        level = course_node.data.get("level", "")
         if level not in _CEFR_LEVELS:
             _blocking(
                 report,
                 "INVALID_COURSE_LEVEL",
-                f"courses[{ci}].level",
+                f"{course_node.path}.level",
                 f"course level '{level}' is not a valid CEFR level",
             )
 
 
 def _check_unique_lesson_orders(
-    artifact: dict[str, Any], report: ValidationReport
+    index: ArtifactIndex, report: ValidationReport
 ) -> None:
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            orders = [
-                lesson.get("order_index")
-                for lesson in (unit.get("lessons") or [])
-            ]
-            if len(orders) != len(set(orders)):
-                _blocking(
-                    report,
-                    "DUPLICATE_LESSON_ORDER",
-                    f"courses[{ci}].units[{ui}].lessons[*].order_index",
-                    "lesson order_index values must be unique within a unit",
-                )
+    for unit_node in index.units:
+        orders = [lesson.data.get("order_index") for lesson in unit_node.lessons]
+        if len(orders) != len(set(orders)):
+            _blocking(
+                report,
+                "DUPLICATE_LESSON_ORDER",
+                f"{unit_node.path}.lessons[*].order_index",
+                "lesson order_index values must be unique within a unit",
+            )
 
 
 def _check_definition_length(
-    artifact: dict[str, Any], report: ValidationReport
+    index: ArtifactIndex, report: ValidationReport
 ) -> None:
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for vi, vocab in enumerate(lesson.get("vocabulary") or []):
-                    definition = str(vocab.get("definition") or "")
-                    path = f"courses[{ci}].units[{ui}].lessons[{li}].vocabulary[{vi}].definition"
-                    if len(definition) < _DEF_MIN_CHARS:
-                        _blocking(
-                            report,
-                            "DEFINITION_TOO_SHORT",
-                            path,
-                            f"definition must be at least {_DEF_MIN_CHARS} characters",
-                        )
-                    elif len(definition) > _DEF_MAX_CHARS:
-                        _blocking(
-                            report,
-                            "DEFINITION_TOO_LONG",
-                            path,
-                            f"definition must not exceed {_DEF_MAX_CHARS} characters",
-                        )
-
-
-def _check_pos_enum(artifact: dict[str, Any], report: ValidationReport) -> None:
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for vi, vocab in enumerate(lesson.get("vocabulary") or []):
-                    pos = vocab.get("part_of_speech", "")
-                    if pos not in _POS_VALUES:
-                        _blocking(
-                            report,
-                            "INVALID_POS",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].vocabulary[{vi}].part_of_speech",
-                            f"part_of_speech '{pos}' is not a recognised value",
-                        )
-
-
-def _check_cefr_enum(artifact: dict[str, Any], report: ValidationReport) -> None:
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for vi, vocab in enumerate(lesson.get("vocabulary") or []):
-                    level = vocab.get("difficulty_level", "")
-                    if level not in _CEFR_LEVELS:
-                        _blocking(
-                            report,
-                            "INVALID_VOCAB_CEFR",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].vocabulary[{vi}].difficulty_level",
-                            f"difficulty_level '{level}' is not a valid CEFR level",
-                        )
+    for vocab_node in index.vocabulary:
+        definition = str(vocab_node.data.get("definition") or "")
+        path = f"{vocab_node.path}.definition"
+        if len(definition) < _DEF_MIN_CHARS:
+            _blocking(
+                report,
+                "DEFINITION_TOO_SHORT",
+                path,
+                f"definition must be at least {_DEF_MIN_CHARS} characters",
+            )
+        elif len(definition) > _DEF_MAX_CHARS:
+            _blocking(
+                report,
+                "DEFINITION_TOO_LONG",
+                path,
+                f"definition must not exceed {_DEF_MAX_CHARS} characters",
+            )
+
+
+def _check_pos_enum(index: ArtifactIndex, report: ValidationReport) -> None:
+    for vocab_node in index.vocabulary:
+        pos = vocab_node.data.get("part_of_speech", "")
+        if pos not in _POS_VALUES:
+            _blocking(
+                report,
+                "INVALID_POS",
+                f"{vocab_node.path}.part_of_speech",
+                f"part_of_speech '{pos}' is not a recognised value",
+            )
+
+
+def _check_cefr_enum(index: ArtifactIndex, report: ValidationReport) -> None:
+    for vocab_node in index.vocabulary:
+        level = vocab_node.data.get("difficulty_level", "")
+        if level not in _CEFR_LEVELS:
+            _blocking(
+                report,
+                "INVALID_VOCAB_CEFR",
+                f"{vocab_node.path}.difficulty_level",
+                f"difficulty_level '{level}' is not a valid CEFR level",
+            )
 
 
 def _check_translation_shape(
-    artifact: dict[str, Any], report: ValidationReport
+    index: ArtifactIndex, report: ValidationReport
 ) -> None:
     """Warn when translation_vi is non-null but suspiciously short."""
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for vi, vocab in enumerate(lesson.get("vocabulary") or []):
-                    tv = vocab.get("translation_vi")
-                    if tv is not None and len(str(tv).strip()) < 1:
-                        _warn(
-                            report,
-                            "EMPTY_TRANSLATION_VI",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].vocabulary[{vi}].translation_vi",
-                            "translation_vi is present but empty",
-                        )
-
-
-def _check_urls(artifact: dict[str, Any], report: ValidationReport) -> None:
+    for vocab_node in index.vocabulary:
+        tv = vocab_node.data.get("translation_vi")
+        if tv is not None and len(str(tv).strip()) < 1:
+            _warn(
+                report,
+                "EMPTY_TRANSLATION_VI",
+                f"{vocab_node.path}.translation_vi",
+                "translation_vi is present but empty",
+            )
+
+
+def _check_urls(index: ArtifactIndex, report: ValidationReport) -> None:
     """Blocking: any non-null source_url must be a valid HTTP/S URL."""
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for vi, vocab in enumerate(lesson.get("vocabulary") or []):
-                    url = vocab.get("source_url")
-                    if url is not None and not _is_valid_url(url):
-                        _blocking(
-                            report,
-                            "INVALID_SOURCE_URL",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].vocabulary[{vi}].source_url",
-                            "source_url must be a valid http/https URL when provided",
-                        )
-                for ei, exercise in enumerate(lesson.get("exercises") or []):
-                    for url_field in ("audio_url", "image_url"):
-                        url = exercise.get(url_field)
-                        if url is not None and not _is_valid_url(url):
-                            _blocking(
-                                report,
-                                "INVALID_EXERCISE_URL",
-                                f"courses[{ci}].units[{ui}].lessons[{li}].exercises[{ei}].{url_field}",
-                                f"{url_field} must be a valid http/https URL when provided",
-                            )
-
-
-def _check_exercise_ids(artifact: dict[str, Any], report: ValidationReport) -> None:
+    for vocab_node in index.vocabulary:
+        url = vocab_node.data.get("source_url")
+        if url is not None and not _is_valid_url(url):
+            _blocking(
+                report,
+                "INVALID_SOURCE_URL",
+                f"{vocab_node.path}.source_url",
+                "source_url must be a valid http/https URL when provided",
+            )
+    for exercise_node in index.exercises:
+        for url_field in ("audio_url", "image_url"):
+            url = exercise_node.data.get(url_field)
+            if url is not None and not _is_valid_url(url):
+                _blocking(
+                    report,
+                    "INVALID_EXERCISE_URL",
+                    f"{exercise_node.path}.{url_field}",
+                    f"{url_field} must be a valid http/https URL when provided",
+                )
+
+
+def _check_exercise_ids(index: ArtifactIndex, report: ValidationReport) -> None:
     """Exercise IDs must be unique within the whole artifact."""
     seen: set[str] = set()
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for ei, exercise in enumerate(lesson.get("exercises") or []):
-                    eid = exercise.get("id") or ""
-                    if not eid:
-                        _blocking(
-                            report,
-                            "EXERCISE_MISSING_ID",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].exercises[{ei}].id",
-                            "exercise id must not be empty",
-                        )
-                    elif eid in seen:
-                        _blocking(
-                            report,
-                            "DUPLICATE_EXERCISE_ID",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].exercises[{ei}].id",
-                            f"exercise id '{eid}' is duplicated across the artifact",
-                        )
-                    else:
-                        seen.add(eid)
+    for exercise_node in index.exercises:
+        eid = exercise_node.data.get("id") or ""
+        if not eid:
+            _blocking(
+                report,
+                "EXERCISE_MISSING_ID",
+                f"{exercise_node.path}.id",
+                "exercise id must not be empty",
+            )
+        elif eid in seen:
+            _blocking(
+                report,
+                "DUPLICATE_EXERCISE_ID",
+                f"{exercise_node.path}.id",
+                f"exercise id '{eid}' is duplicated across the artifact",
+            )
+        else:
+            seen.add(eid)
 
 
 def _check_exercise_type_ui_type(
-    artifact: dict[str, Any], report: ValidationReport
+    index: ArtifactIndex, report: ValidationReport
 ) -> None:
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for ei, exercise in enumerate(lesson.get("exercises") or []):
-                    etype = exercise.get("type", "")
-                    ui_type = exercise.get("ui_type", "")
-                    base = f"courses[{ci}].units[{ui}].lessons[{li}].exercises[{ei}]"
-                    if etype not in _EXERCISE_TYPES:
-                        _blocking(
-                            report,
-                            "INVALID_EXERCISE_TYPE",
-                            f"{base}.type",
-                            f"exercise type '{etype}' is not recognised",
-                        )
-                    if not ui_type:
-                        _blocking(
-                            report,
-                            "MISSING_UI_TYPE",
-                            f"{base}.ui_type",
-                            "ui_type must not be empty",
-                        )
-                    elif _exercise_type_mapping().get(ui_type) != etype:
-                        _blocking(
-                            report,
-                            "EXERCISE_UI_TYPE_MISMATCH",
-                            f"{base}.ui_type",
-                            f"ui_type '{ui_type}' is not valid for exercise type '{etype}'",
-                        )
-
-
-def _check_options(artifact: dict[str, Any], report: ValidationReport) -> None:
+    for exercise_node in index.exercises:
+        exercise = exercise_node.data
+        etype = exercise.get("type", "")
+        ui_type = exercise.get("ui_type", "")
+        base = exercise_node.path
+        if etype not in _EXERCISE_TYPES:
+            _blocking(
+                report,
+                "INVALID_EXERCISE_TYPE",
+                f"{base}.type",
+                f"exercise type '{etype}' is not recognised",
+            )
+        if not ui_type:
+            _blocking(
+                report,
+                "MISSING_UI_TYPE",
+                f"{base}.ui_type",
+                "ui_type must not be empty",
+            )
+        elif _exercise_type_mapping().get(ui_type) != etype:
+            _blocking(
+                report,
+                "EXERCISE_UI_TYPE_MISMATCH",
+                f"{base}.ui_type",
+                f"ui_type '{ui_type}' is not valid for exercise type '{etype}'",
+            )
+
+
+def _check_options(index: ArtifactIndex, report: ValidationReport) -> None:
     """multiple_choice exercises must have at least 2 options."""
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for ei, exercise in enumerate(lesson.get("exercises") or []):
-                    if exercise.get("type") == "multiple_choice":
-                        options = exercise.get("options") or []
-                        if len(options) < 2:
-                            _blocking(
-                                report,
-                                "MC_INSUFFICIENT_OPTIONS",
-                                f"courses[{ci}].units[{ui}].lessons[{li}].exercises[{ei}].options",
-                                "multiple_choice exercise must have at least 2 options",
-                            )
+    for exercise_node in index.exercises:
+        exercise = exercise_node.data
+        if exercise.get("type") == "multiple_choice":
+            options = exercise.get("options") or []
+            if len(options) < 2:
+                _blocking(
+                    report,
+                    "MC_INSUFFICIENT_OPTIONS",
+                    f"{exercise_node.path}.options",
+                    "multiple_choice exercise must have at least 2 options",
+                )
 
 
 def _check_speaking_listening_text(
-    artifact: dict[str, Any], report: ValidationReport
+    index: ArtifactIndex, report: ValidationReport
 ) -> None:
     """Exercises with audio_url must have a non-empty question for listening."""
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                for ei, exercise in enumerate(lesson.get("exercises") or []):
-                    audio_url = exercise.get("audio_url")
-                    question = str(exercise.get("question") or "").strip()
-                    if audio_url and not question:
-                        _blocking(
-                            report,
-                            "MISSING_AUDIO_QUESTION",
-                            f"courses[{ci}].units[{ui}].lessons[{li}].exercises[{ei}].question",
-                            "exercises with audio_url must have a non-empty question",
-                        )
-
-
-def _check_counts(artifact: dict[str, Any], report: ValidationReport) -> None:
+    for exercise_node in index.exercises:
+        audio_url = exercise_node.data.get("audio_url")
+        question = str(exercise_node.data.get("question") or "").strip()
+        if audio_url and not question:
+            _blocking(
+                report,
+                "MISSING_AUDIO_QUESTION",
+                f"{exercise_node.path}.question",
+                "exercises with audio_url must have a non-empty question",
+            )
+
+
+def _check_counts(index: ArtifactIndex, report: ValidationReport) -> None:
     """Warn when lesson vocabulary or exercise counts look off."""
-    courses = artifact.get("courses") or []
-    for ci, course in enumerate(courses):
-        for ui, unit in enumerate(course.get("units") or []):
-            for li, lesson in enumerate(unit.get("lessons") or []):
-                vocab_count = len(lesson.get("vocabulary") or [])
-                ex_count = len(lesson.get("exercises") or [])
-                path_base = f"courses[{ci}].units[{ui}].lessons[{li}]"
-                if vocab_count == 0:
-                    _blocking(
-                        report,
-                        "NO_VOCABULARY",
-                        f"{path_base}.vocabulary",
-                        "lesson must have at least one vocabulary item",
-                    )
-                if ex_count == 0:
-                    _blocking(
-                        report,
-                        "NO_EXERCISES",
-                        f"{path_base}.exercises",
-                        "lesson must have at least one exercise",
-                    )
+    for lesson_node in index.lessons:
+        vocab_count = len(lesson_node.vocabulary)
+        ex_count = len(lesson_node.exercises)
+        if vocab_count == 0:
+            _blocking(
+                report,
+                "NO_VOCABULARY",
+                f"{lesson_node.path}.vocabulary",
+                "lesson must have at least one vocabulary item",
+            )
+        if ex_count == 0:
+            _blocking(
+                report,
+                "NO_EXERCISES",
+                f"{lesson_node.path}.exercises",
+                "lesson must have at least one exercise",
+            )
 
 
-def _collect_metrics(artifact: dict[str, Any]) -> dict[str, Any]:
-    courses = artifact.get("courses") or []
-    total_units = 0
-    total_lessons = 0
-    total_vocab = 0
-    total_exercises = 0
-    for course in courses:
-        for unit in course.get("units") or []:
-            total_units += 1
-            for lesson in unit.get("lessons") or []:
-                total_lessons += 1
-                total_vocab += len(lesson.get("vocabulary") or [])
-                total_exercises += len(lesson.get("exercises") or [])
+def _collect_metrics(index: ArtifactIndex) -> dict[str, Any]:
     return {
-        "course_count": len(courses),
-        "unit_count": total_units,
-        "lesson_count": total_lessons,
-        "vocabulary_count": total_vocab,
-        "exercise_count": total_exercises,
+        "course_count": len(index.courses),
+        "unit_count": len(index.units),
+        "lesson_count": len(index.lessons),
+        "vocabulary_count": len(index.vocabulary),
+        "exercise_count": len(index.exercises),
     }
 
 
@@ -843,19 +783,22 @@ def validate_artifact(
     _check_schema_version(artifact, report)
     _check_manifest_coverage(artifact, report, pins, admin_upload)
     _check_courses_present(artifact, report)
-    _check_course_levels(artifact, report)
-    _check_provenance(artifact, report, pins)
-    _check_unique_lesson_orders(artifact, report)
-    _check_definition_length(artifact, report)
-    _check_pos_enum(artifact, report)
-    _check_cefr_enum(artifact, report)
-    _check_translation_shape(artifact, report)
-    _check_urls(artifact, report)
-    _check_exercise_ids(artifact, report)
-    _check_exercise_type_ui_type(artifact, report)
-    _check_options(artifact, report)
-    _check_speaking_listening_text(artifact, report)
-    _check_counts(artifact, report)
-
-    report.metrics = _collect_metrics(artifact)
+    artifact_index = build_artifact_index(artifact)
+    for issue in artifact_index.structural_errors:
+        _blocking(report, issue.code, issue.path, issue.message)
+    _check_course_levels(artifact_index, report)
+    _check_provenance(artifact, artifact_index, report, pins)
+    _check_unique_lesson_orders(artifact_index, report)
+    _check_definition_length(artifact_index, report)
+    _check_pos_enum(artifact_index, report)
+    _check_cefr_enum(artifact_index, report)
+    _check_translation_shape(artifact_index, report)
+    _check_urls(artifact_index, report)
+    _check_exercise_ids(artifact_index, report)
+    _check_exercise_type_ui_type(artifact_index, report)
+    _check_options(artifact_index, report)
+    _check_speaking_listening_text(artifact_index, report)
+    _check_counts(artifact_index, report)
+
+    report.metrics = _collect_metrics(artifact_index)
     return report
diff --git a/backend-service/app/services/item_effects_service.py b/backend-service/app/services/item_effects_service.py
index 038aa691..508ca73a 100644
--- a/backend-service/app/services/item_effects_service.py
+++ b/backend-service/app/services/item_effects_service.py
@@ -13,22 +13,25 @@
 from datetime import datetime, timedelta, timezone
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select, and_, update
+from sqlalchemy.exc import IntegrityError
 
-from app.models.gamification import UserInventory, ShopItem
+from app.core.shop_catalog import GAME_POWERUP_ITEM_TYPES
+from app.models.gamification import ChallengeRewardClaim, UserInventory, ShopItem
 from app.models.progress import LessonAttempt, Streak
 
 
 class ItemEffectsService:
     """Service for managing item usage and effects."""
-    
+
+    COSMETIC_ITEM_TYPES = frozenset({"avatar", "theme"})
+
     # Item type handlers
     ITEM_HANDLERS = {
         'streak_freeze': '_handle_streak_freeze',
         'double_xp': '_handle_double_xp',
         'hint_pack': '_handle_hint_pack',
         'heart_refill': '_handle_heart_refill',
-        'avatar': '_handle_cosmetic',
-        'theme': '_handle_cosmetic',
+        **{item_type: '_handle_instant_game_powerup' for item_type in GAME_POWERUP_ITEM_TYPES},
     }
     
     def __init__(self, db: AsyncSession):
@@ -74,6 +77,12 @@ async def use_item(
         
         if not shop_item:
             return False, "Shop item not found", None
+
+        if shop_item.item_type in self.COSMETIC_ITEM_TYPES:
+            return False, (
+                f"{shop_item.item_type} items are permanent cosmetics. "
+                "Equip them from the dedicated inventory endpoint."
+            ), None
         
         # Get handler for this item type
         handler_name = self.ITEM_HANDLERS.get(shop_item.item_type)
@@ -165,12 +174,13 @@ async def _handle_hint_pack(
         if not attempt:
             return False, "Start a lesson before using a hint pack", None
 
-        attempt.bonus_hints += hint_count
+        attempt.bonus_hints = (attempt.bonus_hints or 0) + hint_count
+        hints_used = attempt.hints_used or 0
         return True, f"Added {hint_count} hints to your active lesson!", {
             "hints_added": hint_count,
             "hints_remaining": max(
                 0,
-                3 + attempt.bonus_hints - attempt.hints_used,
+                3 + attempt.bonus_hints - hints_used,
             ),
             "effect": "hints"
         }
@@ -209,16 +219,21 @@ async def _get_active_lesson_attempt(
         )
         return result.scalars().first()
     
-    async def _handle_cosmetic(
+    async def _handle_instant_game_powerup(
         self,
         user_id: UUID,
         inventory: UserInventory,
         shop_item: ShopItem,
     ) -> Tuple[bool, str, Optional[Dict]]:
-        """Handle cosmetic items (avatars, themes) - just mark as owned/active."""
-        return True, f"{shop_item.name} equipped!", {
+        """Handle one-shot in-game power-ups (time freeze, skip, reveal, shield, etc.).
+
+        These have no server-tracked state — the mini-games apply the effect
+        client-side. The handler just validates and echoes the item's effects
+        payload back so the client knows what to do.
+        """
+        return True, f"{shop_item.name} ready!", {
             "item_type": shop_item.item_type,
-            "effect": "cosmetic"
+            **(shop_item.effects or {}),
         }
     
     async def get_active_boosts(self, user_id: UUID) -> List[Dict[str, Any]]:
@@ -235,7 +250,7 @@ async def get_active_boosts(self, user_id: UUID) -> List[Dict[str, Any]]:
             .where(
                 and_(
                     UserInventory.user_id == user_id,
-                    UserInventory.is_active == True,
+                    UserInventory.is_active.is_(True),
                     UserInventory.expires_at > now
                 )
             )
@@ -288,7 +303,7 @@ async def cleanup_expired_boosts(self, user_id: UUID) -> int:
             .where(
                 and_(
                     UserInventory.user_id == user_id,
-                    UserInventory.is_active == True,
+                    UserInventory.is_active.is_(True),
                     UserInventory.expires_at <= now
                 )
             )
@@ -319,9 +334,28 @@ async def claim_challenge_reward(
         """
         from app.models.progress import DailyActivity
         from app.crud.gamification import WalletCRUD
-        from datetime import date
         
-        today = date.today()
+        today = datetime.now(timezone.utc).date()
+        claim_date = datetime.combine(
+            today,
+            datetime.min.time(),
+            tzinfo=timezone.utc,
+        )
+
+        existing_claim = await self.db.execute(
+            select(ChallengeRewardClaim).where(
+                and_(
+                    ChallengeRewardClaim.user_id == user_id,
+                    ChallengeRewardClaim.challenge_id == challenge_id,
+                    ChallengeRewardClaim.claim_date == claim_date,
+                )
+            )
+        )
+        if existing_claim.scalar_one_or_none():
+            return False, "Reward already claimed today", {
+                "challenge_id": challenge_id,
+                "already_claimed": True,
+            }
 
         # Award XP to User.total_xp and DailyActivity
         if xp_reward > 0:
@@ -360,8 +394,26 @@ async def claim_challenge_reward(
                 user_id,
                 gems_reward,
                 source="daily_challenge",
-                description=f"Challenge reward: {challenge_id}"
+                description=f"Challenge reward: {challenge_id}",
+                commit=False,
             )
+
+        self.db.add(ChallengeRewardClaim(
+            user_id=user_id,
+            challenge_id=challenge_id,
+            claim_date=claim_date,
+            xp_reward=xp_reward,
+            gems_reward=gems_reward,
+        ))
+
+        try:
+            await self.db.commit()
+        except IntegrityError:
+            await self.db.rollback()
+            return False, "Reward already claimed today", {
+                "challenge_id": challenge_id,
+                "already_claimed": True,
+            }
         
         return True, f"Claimed! +{xp_reward} XP" + (f" +{gems_reward} gems" if gems_reward else ""), {
             "xp_earned": xp_reward,
diff --git a/backend-service/app/services/notification_campaign/segmenter.py b/backend-service/app/services/notification_campaign/segmenter.py
index 7fdfdc49..9ae5ad89 100644
--- a/backend-service/app/services/notification_campaign/segmenter.py
+++ b/backend-service/app/services/notification_campaign/segmenter.py
@@ -38,7 +38,7 @@ async def segment_users(
     min_streak = filters.get("min_streak")
     inactive_days = filters.get("inactive_days")
 
-    conditions = [User.is_active == True]
+    conditions = [User.is_active.is_(True)]
 
     if cefr_levels:
         normalized = [lvl.upper() for lvl in cefr_levels]
@@ -47,7 +47,7 @@ async def segment_users(
     if inactive_days is not None:
         cutoff = datetime.now(UTC) - timedelta(days=inactive_days)
         conditions.append(
-            (User.last_login < cutoff) | (User.last_login == None)
+            (User.last_login < cutoff) | User.last_login.is_(None)
         )
 
     if has_fcm_required:
@@ -55,7 +55,7 @@ async def segment_users(
             exists(
                 select(UserDevice.id).where(
                     UserDevice.user_id == User.id,
-                    UserDevice.fcm_token != None,
+                    UserDevice.fcm_token.is_not(None),
                     UserDevice.fcm_token != "",
                 )
             )
@@ -98,7 +98,7 @@ async def segment_users(
             await db.execute(
                 select(UserDevice.user_id, UserDevice.fcm_token).where(
                     UserDevice.user_id.in_([row.id for row in rows]),
-                    UserDevice.fcm_token != None,
+                    UserDevice.fcm_token.is_not(None),
                     UserDevice.fcm_token != "",
                 )
             )
diff --git a/backend-service/app/services/proficiency_service.py b/backend-service/app/services/proficiency_service.py
index 1c2790cb..429b6b7d 100644
--- a/backend-service/app/services/proficiency_service.py
+++ b/backend-service/app/services/proficiency_service.py
@@ -12,24 +12,18 @@
 5. Trend analysis (improving or declining)
 """
 
-from typing import Optional, List, Dict, Tuple
-from datetime import datetime, timedelta
-from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy import select, func, and_
+from datetime import UTC, datetime
 
 from app.schemas.proficiency import (
-    SkillType,
-    ProficiencyLevel,
-    SkillAssessment,
-    ProficiencyProfile,
-    LevelThreshold,
     LEVEL_THRESHOLDS,
     ExerciseResult,
-    ProficiencyAssessmentResult,
     LevelCheckResponse,
+    ProficiencyAssessmentResult,
+    ProficiencyLevel,
+    ProficiencyProfile,
+    SkillType,
 )
 
-
 # Skill weights for overall score calculation
 SKILL_WEIGHTS = {
     SkillType.VOCABULARY: 0.25,
@@ -63,22 +57,22 @@
 
 class ProficiencyService:
     """Service for calculating and managing user proficiency."""
-    
+
     @staticmethod
     def get_level_index(level: ProficiencyLevel) -> int:
         """Get numeric index of level (0 = A1, 5 = C2)."""
         return LEVEL_ORDER.index(level)
-    
+
     @staticmethod
-    def get_next_level(level: ProficiencyLevel) -> Optional[ProficiencyLevel]:
+    def get_next_level(level: ProficiencyLevel) -> ProficiencyLevel | None:
         """Get the next level, or None if at C2."""
         idx = LEVEL_ORDER.index(level)
         if idx >= len(LEVEL_ORDER) - 1:
             return None
         return LEVEL_ORDER[idx + 1]
-    
+
     @staticmethod
-    def get_previous_level(level: ProficiencyLevel) -> Optional[ProficiencyLevel]:
+    def get_previous_level(level: ProficiencyLevel) -> ProficiencyLevel | None:
         """Get the previous level, or None if at A1."""
         idx = LEVEL_ORDER.index(level)
         if idx <= 0:
@@ -92,7 +86,7 @@ def evaluate_exam_gated_promotion(
         passed: bool,
         score: float,
         passing_score: float = 70.0,
-    ) -> Dict[str, object]:
+    ) -> dict[str, object]:
         """
         Evaluate whether a user is eligible for CEFR promotion via exam gate.
 
@@ -142,7 +136,7 @@ def apply_exam_gated_promotion(
         passed: bool,
         score: float,
         passing_score: float = 70.0,
-    ) -> Tuple[ProficiencyLevel, Dict[str, object]]:
+    ) -> tuple[ProficiencyLevel, dict[str, object]]:
         """Apply exam-gated decision and return resulting level plus decision payload."""
         decision = ProficiencyService.evaluate_exam_gated_promotion(
             current_level=current_level,
@@ -156,51 +150,51 @@ def apply_exam_gated_promotion(
         if decision.get("promoted") and isinstance(promoted_to, ProficiencyLevel):
             return promoted_to, decision
         return current_level, decision
-    
+
     @staticmethod
     def calculate_skill_score(
-        exercises: List[ExerciseResult],
+        exercises: list[ExerciseResult],
         skill: SkillType,
-        current_score: float = 0,
-        decay_factor: float = 0.95
-    ) -> Tuple[float, float]:
+        current_score: float | None = 0,
+        decay_factor: float = 0.95,
+    ) -> tuple[float, float]:
         """
         Calculate updated skill score using Exponential Moving Average (EMA).
-        
+
         This gives more weight to recent exercises while still considering
         historical performance. Exercises at higher difficulty levels
         contribute more to the score.
-        
+
         Args:
             exercises: List of exercise results for this skill
             skill: The skill type being assessed
             current_score: Current skill score (0-100)
             decay_factor: How much to weight historical score (0.95 = 95% history)
-            
+
         Returns:
             Tuple of (new_score, confidence)
         """
+        normalized_current_score = current_score or 0.0
+
         if not exercises:
-            return current_score, 0.0
-        
+            return normalized_current_score, 0.0
+
         # Filter exercises for this skill
         skill_exercises = [e for e in exercises if e.skill == skill]
         if not skill_exercises:
-            return current_score, 0.0
-        
+            return normalized_current_score, 0.0
+
         # Calculate weighted average of new exercise scores
         total_weight = 0.0
         weighted_sum = 0.0
-        
+
         for exercise in skill_exercises:
             # Weight by difficulty level
-            difficulty_mult = LEVEL_DIFFICULTY_MULTIPLIER.get(
-                exercise.difficulty_level, 1.0
-            )
-            
+            difficulty_mult = LEVEL_DIFFICULTY_MULTIPLIER.get(exercise.difficulty_level, 1.0)
+
             # Correct answers at higher difficulty worth more
             weight = difficulty_mult
-            
+
             # Add bonus for being correct at user's level or above
             if exercise.is_correct:
                 # Score contribution (0-100 range)
@@ -208,70 +202,72 @@ def calculate_skill_score(
             else:
                 # Incorrect answers still contribute but less
                 score_contribution = exercise.score * 0.5
-            
+
             weighted_sum += score_contribution * weight
             total_weight += weight
-        
+
         if total_weight == 0:
-            return current_score, 0.0
-        
+            return normalized_current_score, 0.0
+
         # New score from recent exercises
         new_exercise_score = weighted_sum / total_weight
-        
+
         # Blend with historical score using EMA
-        if current_score > 0:
-            final_score = (decay_factor * current_score) + ((1 - decay_factor) * new_exercise_score)
+        if normalized_current_score > 0:
+            final_score = (decay_factor * normalized_current_score) + (
+                (1 - decay_factor) * new_exercise_score
+            )
         else:
             # First time scoring this skill
             final_score = new_exercise_score
-        
+
         # Clamp to valid range
         final_score = max(0, min(100, final_score))
-        
+
         # Calculate confidence based on number of exercises
         # More exercises = higher confidence
         confidence = min(1.0, len(skill_exercises) / 50)  # 50+ exercises = full confidence
-        
+
         return round(final_score, 2), round(confidence, 2)
-    
+
     @staticmethod
     def calculate_overall_level(
-        skill_scores: Dict[SkillType, float],
+        skill_scores: dict[SkillType, float],
         exercises_completed: int,
         lessons_completed: int,
         accuracy: float,
         streak_days: int = 0,
-        current_level: ProficiencyLevel = ProficiencyLevel.A1
-    ) -> Tuple[ProficiencyLevel, float]:
+        current_level: ProficiencyLevel = ProficiencyLevel.A1,
+    ) -> tuple[ProficiencyLevel, float]:
         """
         Determine user's CEFR level based on skill scores and requirements.
-        
+
         This is the core algorithm that prevents "XP grinding" to higher levels.
         Users must demonstrate competency in multiple skills to advance.
-        
+
         Returns:
             Tuple of (level, progress_to_next_level)
         """
         # Calculate weighted overall score
         overall_score = 0.0
         total_weight = 0.0
-        
+
         for skill, weight in SKILL_WEIGHTS.items():
             if skill in skill_scores:
                 overall_score += skill_scores[skill] * weight
                 total_weight += weight
-        
+
         if total_weight > 0:
             overall_score = overall_score / total_weight * sum(SKILL_WEIGHTS.values())
-        
+
         # Check each level from highest to lowest to find qualifying level
         qualifying_level = ProficiencyLevel.A1
-        
+
         for level in reversed(LEVEL_ORDER):
             threshold = LEVEL_THRESHOLDS.get(level)
             if threshold is None:
                 continue
-            
+
             if ProficiencyService._meets_level_requirements(
                 level=level,
                 skill_scores=skill_scores,
@@ -283,7 +279,7 @@ def calculate_overall_level(
             ):
                 qualifying_level = level
                 break
-        
+
         # Calculate progress to next level
         next_level = ProficiencyService.get_next_level(qualifying_level)
         if next_level:
@@ -298,13 +294,13 @@ def calculate_overall_level(
             )
         else:
             progress = 100.0  # At max level
-        
+
         return qualifying_level, round(progress, 2)
-    
+
     @staticmethod
     def _meets_level_requirements(
         level: ProficiencyLevel,
-        skill_scores: Dict[SkillType, float],
+        skill_scores: dict[SkillType, float],
         overall_score: float,
         exercises_completed: int,
         lessons_completed: int,
@@ -315,7 +311,7 @@ def _meets_level_requirements(
         threshold = LEVEL_THRESHOLDS.get(level)
         if threshold is None:
             return level == ProficiencyLevel.A1
-        
+
         # Check skill score requirements
         checks = [
             skill_scores.get(SkillType.VOCABULARY, 0) >= threshold.min_vocabulary_score,
@@ -330,13 +326,13 @@ def _meets_level_requirements(
             accuracy >= threshold.min_accuracy,
             streak_days >= threshold.min_streak_days,
         ]
-        
+
         return all(checks)
-    
+
     @staticmethod
     def _calculate_progress_to_level(
         target_level: ProficiencyLevel,
-        skill_scores: Dict[SkillType, float],
+        skill_scores: dict[SkillType, float],
         overall_score: float,
         exercises_completed: int,
         lessons_completed: int,
@@ -347,7 +343,7 @@ def _calculate_progress_to_level(
         threshold = LEVEL_THRESHOLDS.get(target_level)
         if threshold is None:
             return 0.0
-        
+
         requirements = [
             (skill_scores.get(SkillType.VOCABULARY, 0), threshold.min_vocabulary_score),
             (skill_scores.get(SkillType.GRAMMAR, 0), threshold.min_grammar_score),
@@ -361,26 +357,26 @@ def _calculate_progress_to_level(
             (accuracy * 100, threshold.min_accuracy * 100),  # Convert to percentage
             (streak_days, threshold.min_streak_days),
         ]
-        
+
         # Calculate average progress across all requirements
         progress_sum = 0.0
         count = 0
-        
+
         for current, required in requirements:
             if required > 0:
                 progress = min(100, (current / required) * 100)
                 progress_sum += progress
                 count += 1
-        
+
         if count == 0:
             return 100.0
-        
+
         return progress_sum / count
-    
+
     @staticmethod
     def get_level_requirements_check(
         current_level: ProficiencyLevel,
-        skill_scores: Dict[SkillType, float],
+        skill_scores: dict[SkillType, float],
         exercises_completed: int,
         lessons_completed: int,
         accuracy: float,
@@ -388,12 +384,12 @@ def get_level_requirements_check(
     ) -> LevelCheckResponse:
         """
         Check what requirements are met/unmet for the next level.
-        
+
         This provides detailed feedback to users about what they need
         to work on to advance their level.
         """
         next_level = ProficiencyService.get_next_level(current_level)
-        
+
         if next_level is None:
             return LevelCheckResponse(
                 user_id="",
@@ -404,7 +400,7 @@ def get_level_requirements_check(
                 overall_progress=100.0,
                 blockers=[],
             )
-        
+
         threshold = LEVEL_THRESHOLDS.get(next_level)
         if threshold is None:
             return LevelCheckResponse(
@@ -416,11 +412,11 @@ def get_level_requirements_check(
                 overall_progress=0.0,
                 blockers=["Level threshold not defined"],
             )
-        
+
         # Build requirements dictionary
         requirements = {}
         blockers = []
-        
+
         # Helper to add requirement check
         def add_req(name: str, current: float, required: float, unit: str = ""):
             met = current >= required
@@ -432,38 +428,66 @@ def add_req(name: str, current: float, required: float, unit: str = ""):
             }
             if not met:
                 blockers.append(f"{name}: need {required}{unit}, have {round(current, 1)}{unit}")
-        
+
         # Check all requirements
-        add_req("Vocabulary Score", skill_scores.get(SkillType.VOCABULARY, 0), 
-                threshold.min_vocabulary_score, "%")
-        add_req("Grammar Score", skill_scores.get(SkillType.GRAMMAR, 0), 
-                threshold.min_grammar_score, "%")
-        
+        add_req(
+            "Vocabulary Score",
+            skill_scores.get(SkillType.VOCABULARY, 0),
+            threshold.min_vocabulary_score,
+            "%",
+        )
+        add_req(
+            "Grammar Score",
+            skill_scores.get(SkillType.GRAMMAR, 0),
+            threshold.min_grammar_score,
+            "%",
+        )
+
         if threshold.min_reading_score > 0:
-            add_req("Reading Score", skill_scores.get(SkillType.READING, 0), 
-                    threshold.min_reading_score, "%")
+            add_req(
+                "Reading Score",
+                skill_scores.get(SkillType.READING, 0),
+                threshold.min_reading_score,
+                "%",
+            )
         if threshold.min_listening_score > 0:
-            add_req("Listening Score", skill_scores.get(SkillType.LISTENING, 0), 
-                    threshold.min_listening_score, "%")
+            add_req(
+                "Listening Score",
+                skill_scores.get(SkillType.LISTENING, 0),
+                threshold.min_listening_score,
+                "%",
+            )
         if threshold.min_speaking_score > 0:
-            add_req("Speaking Score", skill_scores.get(SkillType.SPEAKING, 0), 
-                    threshold.min_speaking_score, "%")
+            add_req(
+                "Speaking Score",
+                skill_scores.get(SkillType.SPEAKING, 0),
+                threshold.min_speaking_score,
+                "%",
+            )
         if threshold.min_writing_score > 0:
-            add_req("Writing Score", skill_scores.get(SkillType.WRITING, 0), 
-                    threshold.min_writing_score, "%")
-        
-        add_req("Overall Score", sum(skill_scores.values()) / max(1, len(skill_scores)), 
-                threshold.min_overall_score, "%")
+            add_req(
+                "Writing Score",
+                skill_scores.get(SkillType.WRITING, 0),
+                threshold.min_writing_score,
+                "%",
+            )
+
+        add_req(
+            "Overall Score",
+            sum(skill_scores.values()) / max(1, len(skill_scores)),
+            threshold.min_overall_score,
+            "%",
+        )
         add_req("Exercises Completed", exercises_completed, threshold.min_exercises_completed)
         add_req("Lessons Completed", lessons_completed, threshold.min_lessons_completed)
         add_req("Accuracy Rate", accuracy * 100, threshold.min_accuracy * 100, "%")
-        
+
         if threshold.min_streak_days > 0:
             add_req("Study Streak", streak_days, threshold.min_streak_days, " days")
-        
+
         # Calculate overall progress
         total_progress = sum(r["progress"] for r in requirements.values()) / len(requirements)
-        
+
         return LevelCheckResponse(
             user_id="",
             current_level=current_level,
@@ -473,41 +497,45 @@ def add_req(name: str, current: float, required: float, unit: str = ""):
             overall_progress=round(total_progress, 1),
             blockers=blockers,
         )
-    
+
     @staticmethod
     def process_exercise_results(
         profile: ProficiencyProfile,
-        results: List[ExerciseResult],
+        results: list[ExerciseResult],
     ) -> ProficiencyAssessmentResult:
         """
         Process exercise results and update proficiency profile.
-        
+
         This is called after a user completes exercises to update their
         skill scores and potentially their level.
         """
         previous_level = profile.overall_level
-        
+
         # Group results by skill
-        skill_results: Dict[SkillType, List[ExerciseResult]] = {}
+        skill_results: dict[SkillType, list[ExerciseResult]] = {}
         for result in results:
             if result.skill not in skill_results:
                 skill_results[result.skill] = []
             skill_results[result.skill].append(result)
-        
+
         # Update each skill score
         skill_updates = {}
         new_skill_scores = {}
-        
+
         for skill_type in SkillType:
             current_assessment = profile.skills.get(skill_type)
-            current_score = current_assessment.score if current_assessment else 0.0
-            
+            current_score = (
+                current_assessment.score
+                if current_assessment and current_assessment.score is not None
+                else 0.0
+            )
+
             new_score, confidence = ProficiencyService.calculate_skill_score(
                 exercises=results,
                 skill=skill_type,
                 current_score=current_score,
             )
-            
+
             skill_updates[skill_type] = {
                 "previous_score": current_score,
                 "new_score": new_score,
@@ -515,13 +543,13 @@ def process_exercise_results(
                 "confidence": confidence,
             }
             new_skill_scores[skill_type] = new_score
-        
+
         # Calculate overall level
         # Note: In production, these should come from database
         exercises_completed = profile.assessment_count + len(results)
         lessons_completed = 0  # Would be fetched from DB
         accuracy = sum(1 for r in results if r.is_correct) / max(1, len(results))
-        
+
         new_level, progress = ProficiencyService.calculate_overall_level(
             skill_scores=new_skill_scores,
             exercises_completed=exercises_completed,
@@ -529,17 +557,17 @@ def process_exercise_results(
             accuracy=accuracy,
             current_level=previous_level,
         )
-        
+
         # Calculate XP (separate from proficiency)
         xp_earned = ProficiencyService._calculate_xp_from_exercises(results)
-        
+
         # Find weakest skills
         sorted_skills = sorted(new_skill_scores.items(), key=lambda x: x[1])
         weakest_skills = [s[0] for s in sorted_skills[:2]]
-        
+
         # Get next level requirements
         next_level = ProficiencyService.get_next_level(new_level)
-        
+
         return ProficiencyAssessmentResult(
             previous_level=previous_level,
             current_level=new_level,
@@ -548,71 +576,73 @@ def process_exercise_results(
             next_level=next_level,
             progress_to_next_level=progress,
             weakest_skills=weakest_skills,
-            recommended_focus=f"Focus on improving your {weakest_skills[0].value} skills" if weakest_skills else None,
+            recommended_focus=f"Focus on improving your {weakest_skills[0].value} skills"
+            if weakest_skills
+            else None,
             xp_earned=xp_earned,
             total_xp=profile.total_xp + xp_earned,
         )
-    
+
     @staticmethod
-    def _calculate_xp_from_exercises(results: List[ExerciseResult]) -> int:
+    def _calculate_xp_from_exercises(results: list[ExerciseResult]) -> int:
         """
         Calculate XP earned from exercises.
-        
+
         XP is for gamification/rewards and is separate from proficiency.
         This keeps the dopamine hit of earning XP while ensuring level
         progression is based on actual skill.
         """
         total_xp = 0
-        
+
         for result in results:
             base_xp = 10  # Base XP per exercise
-            
+
             # Bonus for correct answers
             if result.is_correct:
                 base_xp += 5
-            
+
             # Bonus for higher difficulty
-            difficulty_mult = LEVEL_DIFFICULTY_MULTIPLIER.get(
-                result.difficulty_level, 1.0
-            )
-            
+            difficulty_mult = LEVEL_DIFFICULTY_MULTIPLIER.get(result.difficulty_level, 1.0)
+
             xp = int(base_xp * difficulty_mult)
             total_xp += xp
-        
+
         return total_xp
-    
+
     @staticmethod
     def should_suggest_assessment(profile: ProficiencyProfile) -> bool:
         """
         Determine if the user should take a formal level assessment.
-        
+
         This is suggested when:
         1. Skills suggest they might qualify for next level
         2. Haven't had a formal assessment recently
         3. Significant improvement in scores
         """
         # Check if skills are near next level threshold
-        current_idx = ProficiencyService.get_level_index(profile.overall_level)
         next_level = ProficiencyService.get_next_level(profile.overall_level)
-        
+
         if not next_level:
             return False
-        
+
         # Check if last assessment was over a week ago
         if profile.last_full_assessment:
-            days_since = (datetime.now() - profile.last_full_assessment).days
+            last_assessment = profile.last_full_assessment
+            if last_assessment.tzinfo is None or last_assessment.utcoffset() is None:
+                last_assessment = last_assessment.replace(tzinfo=UTC)
+            days_since = (datetime.now(UTC) - last_assessment).days
             if days_since < 7:
                 return False
-        
+
         # Check if exercise count is significant
         if profile.assessment_count < 50:
             return False
-        
+
         # Check if average skill score is close to next level
         avg_score = sum(s.score for s in profile.skills.values()) / max(1, len(profile.skills))
         threshold = LEVEL_THRESHOLDS.get(next_level)
-        
+
         if threshold and avg_score >= threshold.min_overall_score * 0.85:
             return True
-        
+
         return False
diff --git a/backend-service/app/services/quota_manager.py b/backend-service/app/services/quota_manager.py
index af333b98..a8f9b4a2 100644
--- a/backend-service/app/services/quota_manager.py
+++ b/backend-service/app/services/quota_manager.py
@@ -9,7 +9,7 @@
 """
 
 import logging
-from datetime import date, datetime, timedelta
+from datetime import date, datetime, timedelta, timezone
 from enum import Enum
 from typing import Optional
 
@@ -18,6 +18,10 @@
 logger = logging.getLogger(__name__)
 
 
+def _utc_today() -> date:
+    return datetime.now(timezone.utc).date()
+
+
 class QuotaStatus(Enum):
     """Graduated quota threshold levels."""
     NORMAL = "normal"       # 0-69%   → all requests allowed
@@ -67,7 +71,7 @@ class QuotaManager:
     @classmethod
     def _redis_key(cls, api_name: str) -> str:
         """Generate date-keyed Redis key (auto-resets daily)."""
-        return f"quota:{api_name}:{date.today().isoformat()}"
+        return f"quota:{api_name}:{_utc_today().isoformat()}"
     
     @classmethod
     async def check_status(cls, api_name: str, cost: int = 1) -> QuotaStatus:
@@ -81,15 +85,15 @@ async def check_status(cls, api_name: str, cost: int = 1) -> QuotaStatus:
         Returns:
             QuotaStatus enum value
         """
+        budget = cls.LIMITS.get(api_name)
+        if budget is None:
+            logger.error("Unknown API: %s. No quota limit configured.", api_name)
+            return QuotaStatus.NORMAL
+
         redis = await RedisClient.get_instance()
         if redis is None:
             # Redis down → be conservative, allow but log
-            logger.warning(f"Redis unavailable, assuming NORMAL for {api_name}")
-            return QuotaStatus.NORMAL
-        
-        budget = cls.LIMITS.get(api_name)
-        if budget is None:
-            logger.error(f"Unknown API: {api_name}. No quota limit configured.")
+            logger.warning("Redis unavailable, assuming NORMAL for %s", api_name)
             return QuotaStatus.NORMAL
         
         key = cls._redis_key(api_name)
@@ -140,33 +144,52 @@ async def record_request(cls, api_name: str, cost: int = 1) -> QuotaStatus:
         Returns:
             Updated QuotaStatus after recording
         """
+        if cost < 0:
+            raise ValueError("quota cost must be non-negative")
+
+        budget = cls.LIMITS.get(api_name)
+        if budget is None:
+            logger.error("Unknown API: %s. Quota usage was not recorded.", api_name)
+            return QuotaStatus.NORMAL
+
+        if cost == 0:
+            return await cls.check_status(api_name, cost=0)
+
         redis = await RedisClient.get_instance()
         if redis is None:
-            logger.warning(f"Redis unavailable, cannot track quota for {api_name}")
+            logger.warning("Redis unavailable, cannot track quota for %s", api_name)
             return QuotaStatus.NORMAL
         
         key = cls._redis_key(api_name)
         new_count = await redis.incrby(key, cost)
         await redis.expire(key, 86400)  # Auto-expire after 24h (cleanup)
         
-        budget = cls.LIMITS.get(api_name, 1)
         ratio = new_count / budget
         
         # Log threshold crossings
         if ratio >= 1.0:
             logger.warning(
-                f" BLOCKED: {api_name} at {ratio*100:.0f}% "
-                f"({new_count}/{budget}). No more requests until reset."
+                "Quota BLOCKED: %s at %.0f%% (%s/%s). No more requests until reset.",
+                api_name,
+                ratio * 100,
+                new_count,
+                budget,
             )
         elif ratio >= cls.CRITICAL_THRESHOLD:
             logger.warning(
-                f" CRITICAL: {api_name} at {ratio*100:.0f}% "
-                f"({new_count}/{budget}). Only HIGH priority allowed."
+                "Quota CRITICAL: %s at %.0f%% (%s/%s). Only HIGH priority allowed.",
+                api_name,
+                ratio * 100,
+                new_count,
+                budget,
             )
         elif ratio >= cls.WARNING_THRESHOLD:
             logger.info(
-                f"️ WARNING: {api_name} at {ratio*100:.0f}% "
-                f"({new_count}/{budget}). LOW priority blocked."
+                "Quota WARNING: %s at %.0f%% (%s/%s). LOW priority blocked.",
+                api_name,
+                ratio * 100,
+                new_count,
+                budget,
             )
         
         return await cls.check_status(api_name, cost=0)
@@ -215,11 +238,15 @@ def get_reset_time(cls) -> str:
     @classmethod
     async def reset_quota(cls, api_name: str) -> bool:
         """Manual quota reset (emergency use / admin endpoint)."""
+        if api_name not in cls.LIMITS:
+            logger.error("Unknown API: %s. Quota reset was skipped.", api_name)
+            return False
+
         redis = await RedisClient.get_instance()
         if redis is None:
             return False
         
         key = cls._redis_key(api_name)
         await redis.delete(key)
-        logger.info(f" Manual quota reset for {api_name}")
+        logger.info("Manual quota reset for %s", api_name)
         return True
diff --git a/backend-service/app/services/reminder_service.py b/backend-service/app/services/reminder_service.py
index cae0dbdd..91f8df91 100644
--- a/backend-service/app/services/reminder_service.py
+++ b/backend-service/app/services/reminder_service.py
@@ -110,7 +110,7 @@ async def scan_due_preferences(
         result = await db.execute(
             select(UserReminderPreference)
             .where(
-                UserReminderPreference.enabled == True,
+                UserReminderPreference.enabled.is_(True),
                 UserReminderPreference.next_check_at <= now_utc,
             )
             .order_by(UserReminderPreference.next_check_at)
diff --git a/backend-service/app/services/streak_service.py b/backend-service/app/services/streak_service.py
index 53a28bb7..79d4b0f5 100644
--- a/backend-service/app/services/streak_service.py
+++ b/backend-service/app/services/streak_service.py
@@ -1,5 +1,5 @@
 import logging
-from datetime import date, timedelta
+from datetime import date, datetime, timedelta, timezone
 from uuid import UUID
 from sqlalchemy import select, and_
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -10,6 +10,10 @@
 
 logger = logging.getLogger(__name__)
 
+
+def _utc_today() -> date:
+    return datetime.now(timezone.utc).date()
+
 async def update_user_streak(db: AsyncSession, user_id: UUID) -> tuple[Streak, bool, bool, list]:
     """
     Unified function to update user's streak.
@@ -30,7 +34,7 @@ async def update_user_streak(db: AsyncSession, user_id: UUID) -> tuple[Streak, b
     )
     streak = result.scalar_one_or_none()
     
-    today = date.today()
+    today = _utc_today()
     streak_increased = False
     streak_saved = False
     
diff --git a/backend-service/app/services/user_stats_service.py b/backend-service/app/services/user_stats_service.py
index 67eaf797..5dda8ca4 100644
--- a/backend-service/app/services/user_stats_service.py
+++ b/backend-service/app/services/user_stats_service.py
@@ -46,7 +46,7 @@ async def get_user_stats(db: AsyncSession, user: User) -> UserStatsResponse:
     lessons_completed = (await db.execute(
         select(func.count(LessonCompletion.id)).where(
             LessonCompletion.user_id == user.id,
-            LessonCompletion.is_passed == True,
+            LessonCompletion.is_passed.is_(True),
         )
     )).scalar() or 0
 
@@ -119,7 +119,7 @@ async def get_weekly_activity(db: AsyncSession, user: User) -> WeeklyActivityRes
                 LessonAttempt.user_id == user.id,
                 LessonAttempt.finished_at >= day_start,
                 LessonAttempt.finished_at <= day_end,
-                LessonAttempt.passed == True,
+                LessonAttempt.passed.is_(True),
             )
         )).first()
 
diff --git a/backend-service/app/services/xp_service.py b/backend-service/app/services/xp_service.py
index fb84eb2e..56b6cf2e 100644
--- a/backend-service/app/services/xp_service.py
+++ b/backend-service/app/services/xp_service.py
@@ -105,6 +105,7 @@ async def award_xp_transaction(
     source_id: str | None = None,
     source_detail: str | None = None,
     commit: bool = True,
+    item_multiplier: float = 1.0,
     daily_xp_loader: Callable[
         [uuid.UUID, AsyncSession], Awaitable[int]
     ] = get_daily_xp,
@@ -119,7 +120,7 @@ async def award_xp_transaction(
         )
     if source in REPEAT_SENSITIVE_SOURCES and not source_id:
         raise HTTPException(
-            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
             detail=f"source_id is required for source '{source}' to prevent duplicate awards.",
         )
     if base_xp < 0 or base_xp > MAX_SINGLE_AWARD:
@@ -149,7 +150,7 @@ async def award_xp_transaction(
 
     capped_base_xp = min(base_xp, XP_SOURCE_CAPS[source])
     streak_days = await streak_loader(user.id, db)
-    multiplier = calculate_streak_multiplier(streak_days)
+    multiplier = calculate_streak_multiplier(streak_days) * max(1.0, item_multiplier)
     raw_awarded = int(capped_base_xp * multiplier)
     daily_xp_today = await daily_xp_loader(user.id, db)
     cap_remaining = max(0, DAILY_XP_CAP - daily_xp_today)
diff --git a/backend-service/app/tasks/content_prefetch.py b/backend-service/app/tasks/content_prefetch.py
index 1e8c187b..f637b3a8 100644
--- a/backend-service/app/tasks/content_prefetch.py
+++ b/backend-service/app/tasks/content_prefetch.py
@@ -114,6 +114,7 @@ async def prefetch_youtube(db: AsyncSession) -> dict:
                 api_name="youtube",
                 fetch_fn=lambda cid=channel_id: _fetch_youtube_channel(cid),
                 priority=Priority.LOW,
+                cost=100,
                 redis_ttl=43200,    # 12 hours
                 db_ttl=86400,       # 24 hours
             )
diff --git a/backend-service/app/test_vocab_definitions.py b/backend-service/app/test_vocab_definitions.py
deleted file mode 100644
index 0ceec92e..00000000
--- a/backend-service/app/test_vocab_definitions.py
+++ /dev/null
@@ -1,18 +0,0 @@
-import asyncio
-import sys
-sys.path.insert(0, "/app")
-from sqlalchemy import select
-from app.core.database import engine
-from app.models.vocabulary import VocabularyItem
-
-async def main():
-    async with engine.connect() as conn:
-        for w in ['idiom', 'lexicon']:
-            res = await conn.execute(select(VocabularyItem.word, VocabularyItem.definition, VocabularyItem.part_of_speech).where(VocabularyItem.word == w))
-            for row in res.all():
-                print(f"Word: {row[0]}, POS: {row[2]}")
-                print(f"Def: {row[1]}")
-                print("-" * 30)
-
-if __name__ == "__main__":
-    asyncio.run(main())
diff --git a/backend-service/requirements.txt b/backend-service/requirements.txt
index 783f56ac..a23f488f 100644
--- a/backend-service/requirements.txt
+++ b/backend-service/requirements.txt
@@ -69,3 +69,4 @@ httpx>=0.27.0
 black>=26.5.1
 isort>=8.0.1
 flake8>=7.3.0
+ruff>=0.14.8
diff --git a/backend-service/tests/conftest.py b/backend-service/tests/conftest.py
index 344fa5b9..44530b8c 100644
--- a/backend-service/tests/conftest.py
+++ b/backend-service/tests/conftest.py
@@ -3,17 +3,20 @@
 Shared test fixtures for backend API tests
 """
 
-import pytest
-import asyncio
-import sys
+# ruff: noqa: E402
+
 import os
-from typing import AsyncGenerator
+import sys
+from collections.abc import AsyncGenerator
 from pathlib import Path
+
+import asyncpg
+import pytest
 from httpx import AsyncClient
-from sqlalchemy import text, select
-from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
+from sqlalchemy import select, text
+from sqlalchemy.engine import make_url
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 from sqlalchemy.pool import NullPool
-from uuid import uuid4
 
 BACKEND_SERVICE_ROOT = Path(__file__).resolve().parents[1]
 if str(BACKEND_SERVICE_ROOT) not in sys.path:
@@ -28,14 +31,14 @@
 # does not break ASGI test client requests to http://test.
 os.environ["APP_ENV"] = "testing"
 
-from app.main import app
 from app.core.database import Base, get_db
-from app.core.security import create_access_token, get_password_hash
+from app.core.security import create_access_token
+from app.main import app
+from app.models.course import Course, Lesson, Unit
+from app.models.progress import LessonAttempt
+from app.models.rbac import Role
 from app.models.user import User
-from app.models.course import Course, Unit, Lesson
-from app.models.progress import LessonAttempt, UserProgress, Streak
 from app.models.vocabulary import VocabularyItem
-from app.models.rbac import Role
 
 
 @pytest.fixture(autouse=True)
@@ -46,13 +49,14 @@ def disable_rate_limiting(monkeypatch):
     (not captured in self.dispatch_func), so monkeypatch works correctly.
     """
     from app.core.middleware import RateLimitMiddleware
+
     monkeypatch.setattr(RateLimitMiddleware, "_testing", True)
 
 
 # Test database URL (use separate test database, configurable via environment)
 TEST_DATABASE_URL = os.getenv(
     "TEST_DATABASE_URL",
-    "postgresql+asyncpg://lexilingo:lexilingo_pass@localhost:5432/lexilingo_test"
+    "postgresql+asyncpg://lexilingo:lexilingo_pass@localhost:5432/lexilingo_test",
 )
 
 # Safety guard: refuse to wipe a database whose name does not end with _test.
@@ -75,33 +79,90 @@ async def _reset_public_schema(engine) -> None:
         await conn.run_sync(Base.metadata.create_all)
 
 
+def _quote_pg_identifier(identifier: str) -> str:
+    return f'"{identifier.replace(chr(34), chr(34) * 2)}"'
+
+
+async def _ensure_test_database_exists() -> None:
+    """Create the configured PostgreSQL test database if it is missing."""
+    url = make_url(TEST_DATABASE_URL)
+    if url.get_backend_name() != "postgresql":
+        return
+
+    db_name = url.database
+    if not db_name:
+        raise RuntimeError("TEST_DATABASE_URL must include a database name")
+    if not db_name.endswith("_test"):
+        raise RuntimeError(
+            f"TEST_DATABASE_URL database name '{db_name}' does not end with '_test'."
+        )
+
+    maintenance_db = os.getenv("TEST_MAINTENANCE_DATABASE", "postgres")
+    owner_clause = f" OWNER {_quote_pg_identifier(url.username)}" if url.username else ""
+    connection_attempts = [
+        {
+            "user": url.username,
+            "password": url.password,
+            "database": maintenance_db,
+            "host": url.host or "localhost",
+            "port": url.port or 5432,
+        },
+        {
+            "database": maintenance_db,
+        },
+    ]
+    last_error: Exception | None = None
+
+    for connection_kwargs in connection_attempts:
+        filtered_kwargs = {
+            key: value for key, value in connection_kwargs.items() if value is not None
+        }
+        try:
+            conn = await asyncpg.connect(**filtered_kwargs)
+        except Exception as exc:
+            last_error = exc
+            continue
+
+        try:
+            exists = await conn.fetchval(
+                "SELECT 1 FROM pg_database WHERE datname = $1",
+                db_name,
+            )
+            if not exists:
+                await conn.execute(f"CREATE DATABASE {_quote_pg_identifier(db_name)}{owner_clause}")
+            return
+        except asyncpg.InsufficientPrivilegeError as exc:
+            last_error = exc
+        finally:
+            await conn.close()
+
+    raise RuntimeError(
+        f"Unable to create PostgreSQL test database '{db_name}'. "
+        "Create it manually or use a maintenance role with CREATEDB privileges."
+    ) from last_error
+
+
 @pytest.fixture
 async def db_engine():
     """Create test database engine"""
-    engine = create_async_engine(
-        TEST_DATABASE_URL,
-        poolclass=NullPool,
-        echo=False
-    )
+    await _ensure_test_database_exists()
+
+    engine = create_async_engine(TEST_DATABASE_URL, poolclass=NullPool, echo=False)
 
     await _reset_public_schema(engine)
-    
+
     yield engine
 
     await _reset_public_schema(engine)
-    
+
     await engine.dispose()
 
 
 @pytest.fixture
 async def db_session(db_engine) -> AsyncGenerator[AsyncSession, None]:
     """Create test database session"""
-    async_session = async_sessionmaker(
-        db_engine,
-        class_=AsyncSession,
-        expire_on_commit=False
-    )
-    
+    async_session = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
+
     async with async_session() as session:
         yield session
 
@@ -110,16 +171,16 @@ async def db_session(db_engine) -> AsyncGenerator[AsyncSession, None]:
 async def async_client(db_session: AsyncSession) -> AsyncGenerator[AsyncClient, None]:
     """Create async HTTP client for API testing"""
     from httpx import ASGITransport
-    
+
     async def override_get_db():
         yield db_session
-    
+
     app.dependency_overrides[get_db] = override_get_db
 
     transport = ASGITransport(app=app)
     async with AsyncClient(transport=transport, base_url="http://test") as client:
         yield client
-    
+
     app.dependency_overrides.clear()
 
 
@@ -137,13 +198,13 @@ async def test_user(db_session: AsyncSession) -> User:
         is_verified=True,
         native_language="vi",
         target_language="en",
-        level="beginner"
+        level="beginner",
     )
-    
+
     db_session.add(user)
     await db_session.commit()
     await db_session.refresh(user)
-    
+
     return user
 
 
@@ -160,11 +221,15 @@ async def admin_user(db_session: AsyncSession) -> User:
     # Check if Admin role already exists to avoid unique constraint violations
     res = await db_session.execute(select(Role).where(Role.name == "Admin"))
     admin_role = res.scalar_one_or_none()
-    
+
     if not admin_role:
         admin_role = Role(
-            name="Admin", slug="admin", level=1,
-            description="Admin role", is_system=True, is_active=True
+            name="Admin",
+            slug="admin",
+            level=1,
+            description="Admin role",
+            is_system=True,
+            is_active=True,
         )
         db_session.add(admin_role)
         await db_session.commit()
@@ -173,7 +238,7 @@ async def admin_user(db_session: AsyncSession) -> User:
     # Check if admin user already exists to avoid unique constraint violations
     res_user = await db_session.execute(select(User).where(User.email == "admin@example.com"))
     user = res_user.scalar_one_or_none()
-    
+
     if not user:
         user = User(
             email="admin@example.com",
@@ -193,7 +258,6 @@ async def admin_user(db_session: AsyncSession) -> User:
     return user
 
 
-
 @pytest.fixture
 def admin_headers(admin_user: User) -> dict:
     """Create authentication headers with JWT token for an admin user."""
@@ -211,13 +275,13 @@ async def test_course(db_session: AsyncSession) -> Course:
         level="beginner",
         is_published=True,
         total_xp=1000,
-        estimated_duration=30
+        estimated_duration=30,
     )
-    
+
     db_session.add(course)
     await db_session.commit()
     await db_session.refresh(course)
-    
+
     return course
 
 
@@ -229,13 +293,13 @@ async def test_unit(db_session: AsyncSession, test_course: Course) -> Unit:
         title="Test Unit 1",
         description="First test unit",
         order_index=0,
-        background_color="#2196F3"
+        background_color="#2196F3",
     )
-    
+
     db_session.add(unit)
     await db_session.commit()
     await db_session.refresh(unit)
-    
+
     return unit
 
 
@@ -259,83 +323,78 @@ async def test_lesson(db_session: AsyncSession, test_unit: Unit, test_course: Co
                     "question": "What is the main topic?",
                     "options": ["Grammar fundamentals", "Advanced vocabulary", "Pronunciation"],
                     "correct_answer": "Grammar fundamentals",
-                    "explanation": "This lesson covers grammar fundamentals."
+                    "explanation": "This lesson covers grammar fundamentals.",
                 },
                 {
                     "id": "00000000-0000-0000-0000-000000000002",
                     "type": "fill_blank",
                     "question": "Complete: I ___ learning.",
                     "correct_answer": "am",
-                    "explanation": "Use 'am' for first person singular."
-                }
+                    "explanation": "Use 'am' for first person singular.",
+                },
             ]
-        }
+        },
     )
-    
+
     db_session.add(lesson)
     await db_session.commit()
     await db_session.refresh(lesson)
-    
+
     return lesson
 
 
 @pytest.fixture
-async def test_course_with_units(
-    db_session: AsyncSession,
-    test_course: Course
-) -> Course:
+async def test_course_with_units(db_session: AsyncSession, test_course: Course) -> Course:
     """Create a test course with multiple units and lessons"""
-    
+
     # Create 3 units
     units = []
     for i in range(3):
         unit = Unit(
             course_id=test_course.id,
-            title=f"Unit {i+1}",
-            description=f"Unit {i+1} description",
+            title=f"Unit {i + 1}",
+            description=f"Unit {i + 1} description",
             order_index=i,
-            background_color="#2196F3"
+            background_color="#2196F3",
         )
         db_session.add(unit)
         units.append(unit)
-    
+
     await db_session.flush()
-    
+
     # Create 2 lessons per unit
     for unit in units:
         for j in range(2):
             lesson = Lesson(
                 course_id=test_course.id,
                 unit_id=unit.id,
-                title=f"{unit.title} - Lesson {j+1}",
-                description=f"Lesson {j+1} in {unit.title}",
+                title=f"{unit.title} - Lesson {j + 1}",
+                description=f"Lesson {j + 1} in {unit.title}",
                 order_index=j,
                 lesson_type="vocabulary",
                 xp_reward=50,
                 pass_threshold=70,
-                content={"questions": []}
+                content={"questions": []},
             )
             db_session.add(lesson)
-    
+
     await db_session.commit()
     await db_session.refresh(test_course)
-    
+
     return test_course
 
 
 @pytest.fixture
 async def test_lesson_attempt(
-    db_session: AsyncSession,
-    test_user: User,
-    test_lesson: Lesson
+    db_session: AsyncSession, test_user: User, test_lesson: Lesson
 ) -> LessonAttempt:
     """Create a test lesson attempt"""
-    from datetime import datetime
-    
+    from datetime import UTC, datetime
+
     attempt = LessonAttempt(
         user_id=test_user.id,
         lesson_id=test_lesson.id,
-        started_at=datetime.utcnow(),
+        started_at=datetime.now(UTC),
         total_questions=10,
         lives_remaining=3,
         hints_used=0,
@@ -343,13 +402,13 @@ async def test_lesson_attempt(
         score=0,
         xp_earned=0,
         time_spent_ms=0,
-        correct_answers=0
+        correct_answers=0,
     )
-    
+
     db_session.add(attempt)
     await db_session.commit()
     await db_session.refresh(attempt)
-    
+
     return attempt
 
 
@@ -362,11 +421,11 @@ async def test_vocabulary(db_session: AsyncSession) -> VocabularyItem:
         translation={"vi": "xin chào", "examples": ["Hello, how are you?"]},
         part_of_speech="interjection",
         pronunciation="həˈləʊ",
-        difficulty_level="A1"
+        difficulty_level="A1",
     )
-    
+
     db_session.add(vocab)
     await db_session.commit()
     await db_session.refresh(vocab)
-    
+
     return vocab
diff --git a/backend-service/tests/crud/test_course_crud_queries.py b/backend-service/tests/crud/test_course_crud_queries.py
new file mode 100644
index 00000000..ab3bf5dc
--- /dev/null
+++ b/backend-service/tests/crud/test_course_crud_queries.py
@@ -0,0 +1,19 @@
+from sqlalchemy import select
+from sqlalchemy.dialects import postgresql, sqlite
+
+from app.crud.course import _seed_first_ordering
+from app.models.course import Course
+
+
+def test_seed_first_ordering_uses_portable_sql():
+    stmt = select(Course.id).order_by(_seed_first_ordering(), Course.created_at)
+
+    sqlite_sql = str(stmt.compile(dialect=sqlite.dialect()))
+    postgres_sql = str(stmt.compile(dialect=postgresql.dialect()))
+
+    assert "@>" not in sqlite_sql
+    assert "::jsonb" not in sqlite_sql
+    assert "@>" not in postgres_sql
+    assert "::jsonb" not in postgres_sql
+    assert "LIKE" in sqlite_sql
+    assert "LIKE" in postgres_sql
diff --git a/backend-service/tests/services/test_starter_reward_service.py b/backend-service/tests/services/test_starter_reward_service.py
index 6c424b37..9a842b49 100644
--- a/backend-service/tests/services/test_starter_reward_service.py
+++ b/backend-service/tests/services/test_starter_reward_service.py
@@ -9,6 +9,8 @@
 from app.models.rbac import Role
 from app.models.reward_grant import UserRewardGrant
 from app.models.user import User
+from app.crud.gamification import WalletCRUD
+from app.core.cache import build_cache_key
 from app.services.starter_reward_service import StarterRewardService
 from app.core.firebase_auth import get_or_create_user_from_claims
 
@@ -128,6 +130,25 @@ async def test_mark_seen_is_idempotent(db_session, test_user):
     assert len(grants) == 1
 
 
+async def test_add_gems_invalidates_wallet_cache(db_session, test_user, monkeypatch):
+    deleted = []
+
+    async def fake_delete_cached(key):
+        deleted.append(key)
+
+    monkeypatch.setattr("app.crud.gamification.delete_cached", fake_delete_cached)
+
+    await WalletCRUD.add_gems(
+        db_session,
+        test_user.id,
+        100,
+        source="test",
+        description="test grant",
+    )
+
+    assert deleted == [build_cache_key("wallet", user_id=str(test_user.id))]
+
+
 async def test_first_social_login_receives_reward_only_once(db_session):
     claims = {
         "email": "social@example.com",
diff --git a/backend-service/tests/test_achievement_system.py b/backend-service/tests/test_achievement_system.py
index 13ee58c5..9f9e1a1a 100644
--- a/backend-service/tests/test_achievement_system.py
+++ b/backend-service/tests/test_achievement_system.py
@@ -6,7 +6,7 @@
 
 import pytest
 from uuid import uuid4
-from datetime import datetime, date, timedelta
+from datetime import UTC, datetime, date, timedelta
 from unittest.mock import AsyncMock, patch, MagicMock
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -408,7 +408,7 @@ def test_response_serialization(self):
             rarity="common",
             xp_reward=10,
             gems_reward=5,
-            created_at=datetime.utcnow(),
+            created_at=datetime.now(UTC),
         )
         data = resp.model_dump()
         assert data["slug"] == "test_slug"
diff --git a/backend-service/tests/test_admin_rbac_security.py b/backend-service/tests/test_admin_rbac_security.py
index 81eb7acc..2eb58aa5 100644
--- a/backend-service/tests/test_admin_rbac_security.py
+++ b/backend-service/tests/test_admin_rbac_security.py
@@ -522,7 +522,7 @@ async def test_create_achievement(self, async_client: AsyncClient, admin_headers
 
     @pytest.mark.asyncio
     async def test_create_shop_item(self, async_client: AsyncClient, admin_headers):
-        response = await async_client.post("/api/v1/admin/shop", headers=admin_headers, params={
+        response = await async_client.post("/api/v1/admin/shop", headers=admin_headers, json={
             "name": "Test Item",
             "description": "A test item",
             "item_type": "streak_freeze",
diff --git a/backend-service/tests/test_admin_routes.py b/backend-service/tests/test_admin_routes.py
index 3f31e475..737ff1f7 100644
--- a/backend-service/tests/test_admin_routes.py
+++ b/backend-service/tests/test_admin_routes.py
@@ -399,18 +399,87 @@ async def test_create_shop_item(
         response = await async_client.post(
             "/api/v1/admin/shop",
             headers=admin_headers,
-            params={
+            json={
                 "name": "Test Shop Item",
                 "description": "Test item",
                 "item_type": "test",
                 "price_gems": 100
             }
         )
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
 
+    @pytest.mark.asyncio
+    async def test_create_shop_item_persists_effects_and_icon_url(
+        self,
+        async_client: AsyncClient,
+        admin_headers: dict
+    ):
+        """effects/icon_url must round-trip — admin-created power-ups need a real effects payload to work in-game"""
+        response = await async_client.post(
+            "/api/v1/admin/shop",
+            headers=admin_headers,
+            json={
+                "name": "Test Time Freeze",
+                "description": "Pauses the timer",
+                "item_type": "time_freeze",
+                "price_gems": 10,
+                "icon_url": "assets/icon-library/clock_freeze.png",
+                "effects": {"seconds": 15},
+            }
+        )
+
+        assert response.status_code == 200
+        item_id = response.json()["data"]["id"]
+
+        list_response = await async_client.get(
+            "/api/v1/admin/shop?include_unavailable=true",
+            headers=admin_headers
+        )
+        created = next(
+            item for item in list_response.json()["data"] if item["id"] == item_id
+        )
+        assert created["effects"] == {"seconds": 15}
+        assert created["icon_url"] == "assets/icon-library/clock_freeze.png"
+
+    @pytest.mark.asyncio
+    async def test_update_shop_item_can_change_effects(
+        self,
+        async_client: AsyncClient,
+        admin_headers: dict
+    ):
+        """Admin must be able to retune an existing power-up's effects payload"""
+        create_response = await async_client.post(
+            "/api/v1/admin/shop",
+            headers=admin_headers,
+            json={
+                "name": "Test Lucky Clover",
+                "description": "30% auto-correct chance",
+                "item_type": "lucky_clover",
+                "price_gems": 20,
+                "effects": {"chance": 0.3},
+            }
+        )
+        item_id = create_response.json()["data"]["id"]
+
+        update_response = await async_client.put(
+            f"/api/v1/admin/shop/{item_id}",
+            headers=admin_headers,
+            json={"effects": {"chance": 0.5}}
+        )
+        assert update_response.status_code == 200
+
+        list_response = await async_client.get(
+            "/api/v1/admin/shop?include_unavailable=true",
+            headers=admin_headers
+        )
+        updated = next(
+            item for item in list_response.json()["data"] if item["id"] == item_id
+        )
+        assert updated["effects"] == {"chance": 0.5}
+
 
 class TestAdminSeed:
     """Tests for seed data endpoint"""
diff --git a/backend-service/tests/test_ai_audit_routes.py b/backend-service/tests/test_ai_audit_routes.py
index b07e3a9b..6513bbe2 100644
--- a/backend-service/tests/test_ai_audit_routes.py
+++ b/backend-service/tests/test_ai_audit_routes.py
@@ -1,4 +1,5 @@
 import pytest
+import json
 from types import SimpleNamespace
 from contextlib import asynccontextmanager
 
@@ -6,7 +7,7 @@
 
 from app.main import app
 from app.core.config import settings
-from app.core.dependencies import get_current_user
+from app.core.dependencies import get_current_admin, get_current_user
 from app.routes import ai_audit as ai_audit_route
 
 
@@ -87,3 +88,60 @@ async def _fake_current_user():
             assert payload["events"][0]["request_id"] == "req-123"
     finally:
         app.dependency_overrides.pop(get_current_user, None)
+
+
+@pytest.mark.asyncio
+async def test_admin_quality_summary_aggregates_ai_audit_events(monkeypatch):
+    fake_redis = _FakeRedis()
+    fake_redis.store["ai:audit:all"] = [
+        json.dumps({
+            "request_id": "req-stt",
+            "user_id": "u1",
+            "endpoint": "stt.transcribe",
+            "status": "failed",
+            "latency_ms": 820,
+            "error": "primary failed",
+        }),
+        json.dumps({
+            "request_id": "req-lexi",
+            "user_id": "u2",
+            "endpoint": "lexi.chat",
+            "status": "success",
+            "latency_ms": 240,
+            "metadata": {"pipeline_steps": ["stt_complete", "tts_failed"]},
+        }),
+        json.dumps({
+            "request_id": "req-correction",
+            "user_id": "u3",
+            "endpoint": "writing.correction",
+            "status": "success",
+            "duration_ms": 120,
+            "correction_score": 0.86,
+        }),
+    ]
+
+    async def _fake_get_redis():
+        return fake_redis
+
+    async def _fake_current_admin():
+        return SimpleNamespace(id="admin-1")
+
+    monkeypatch.setattr(ai_audit_route, "get_redis", _fake_get_redis)
+    app.dependency_overrides[get_current_admin] = _fake_current_admin
+
+    try:
+        async with _test_client() as client:
+            response = await client.get("/api/v1/ai-audit/quality-summary?limit=10")
+
+        assert response.status_code == 200
+        payload = response.json()
+        summary = payload["summary"]
+        assert payload["source"] == "ai:audit:all"
+        assert summary["total_events"] == 3
+        assert summary["failure_count"] == 1
+        assert summary["stt"]["failures"] == 1
+        assert summary["tts"]["failures"] == 1
+        assert summary["correction"]["average_score"] == 0.86
+        assert summary["endpoint_breakdown"][0]["total"] == 1
+    finally:
+        app.dependency_overrides.pop(get_current_admin, None)
diff --git a/backend-service/tests/test_api_cache_service.py b/backend-service/tests/test_api_cache_service.py
new file mode 100644
index 00000000..7ab1264a
--- /dev/null
+++ b/backend-service/tests/test_api_cache_service.py
@@ -0,0 +1,57 @@
+from unittest.mock import AsyncMock
+
+import pytest
+
+from app.services import api_cache_service
+from app.services.api_cache_service import APICacheService
+from app.services.quota_manager import QuotaStatus
+
+
+@pytest.mark.asyncio
+async def test_zero_cost_fetch_bypasses_quota_manager(monkeypatch):
+    service = APICacheService(db=object())
+    monkeypatch.setattr(api_cache_service.RedisClient, "get_instance", AsyncMock(return_value=None))
+    monkeypatch.setattr(service, "_get_db_entry", AsyncMock(return_value=None))
+    monkeypatch.setattr(service, "_warm_redis", AsyncMock())
+    monkeypatch.setattr(service, "_upsert_db_entry", AsyncMock())
+    check_status = AsyncMock(side_effect=AssertionError("quota should be skipped"))
+    record_request = AsyncMock(side_effect=AssertionError("quota should be skipped"))
+    monkeypatch.setattr(api_cache_service.QuotaManager, "check_status", check_status)
+    monkeypatch.setattr(api_cache_service.QuotaManager, "record_request", record_request)
+
+    result = await service.get_or_fetch(
+        cache_key="youtube:captions:abc:en",
+        api_name="youtube",
+        fetch_fn=AsyncMock(return_value={"segments": []}),
+        cost=0,
+    )
+
+    assert result.source == "api"
+    assert result.data == {"segments": []}
+    check_status.assert_not_called()
+    record_request.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_fetch_forwards_quota_cost(monkeypatch):
+    service = APICacheService(db=object())
+    monkeypatch.setattr(api_cache_service.RedisClient, "get_instance", AsyncMock(return_value=None))
+    monkeypatch.setattr(service, "_get_db_entry", AsyncMock(return_value=None))
+    monkeypatch.setattr(service, "_warm_redis", AsyncMock())
+    monkeypatch.setattr(service, "_upsert_db_entry", AsyncMock())
+    check_status = AsyncMock(return_value=QuotaStatus.NORMAL)
+    record_request = AsyncMock(return_value=QuotaStatus.NORMAL)
+    monkeypatch.setattr(api_cache_service.QuotaManager, "check_status", check_status)
+    monkeypatch.setattr(api_cache_service.QuotaManager, "record_request", record_request)
+
+    result = await service.get_or_fetch(
+        cache_key="youtube:search:q:english",
+        api_name="youtube",
+        fetch_fn=AsyncMock(return_value={"videos": []}),
+        cost=100,
+    )
+
+    assert result.source == "api"
+    assert result.data == {"videos": []}
+    check_status.assert_awaited_once_with("youtube", cost=100)
+    record_request.assert_awaited_once_with("youtube", cost=100)
diff --git a/backend-service/tests/test_auth_routes.py b/backend-service/tests/test_auth_routes.py
index c1f940fc..3f67e573 100644
--- a/backend-service/tests/test_auth_routes.py
+++ b/backend-service/tests/test_auth_routes.py
@@ -10,14 +10,22 @@
 - POST /auth/forgot-password — always-success anti-enumeration response
 - POST /auth/reset-password  — valid token, invalid token, weak password
 - POST /auth/verify-email    — valid token, invalid token, already verified
+- POST /auth/google          — invalid token, new user, link to unverified local account, blocked link
+- POST /auth/facebook        — invalid token, success, inactive
+- POST /auth/admin/login     — success, wrong role, unverified, inactive
+- POST /auth/admin/request-otp, /auth/admin/verify-otp — anti-enumeration, unverified blocked, success
+- POST /auth/change-password — success, wrong current password, OAuth-only blocked
+- POST /auth/resend-verification — always-success anti-enumeration response
 """
 
 import uuid
 import pytest
-from datetime import datetime
+from datetime import UTC, datetime
 from unittest.mock import AsyncMock, MagicMock, patch
 from httpx import AsyncClient, ASGITransport
 
+from app.core.security import create_access_token
+
 
 BASE = "/api/v1/auth"
 
@@ -29,7 +37,7 @@ def _make_mock_user(
     *,
     is_active: bool = True,
     is_verified: bool = True,
-    provider: list[str] = ["local"],
+    provider: tuple[str, ...] = ("local",),
     hashed_password: str = "$2b$12$LQv3c1yqBWVHxkd0LHAkCOYz6TtxMQJqhN8/LewY5GyYzS6NzE3Fu",
 ) -> MagicMock:
     """Build a minimal mock User ORM object."""
@@ -41,7 +49,22 @@ def _make_mock_user(
     u.hashed_password = hashed_password
     u.is_active = is_active
     u.is_verified = is_verified
-    u.provider = provider
+    u.provider = list(provider)
+    # MagicMock auto-generates truthy attributes for undefined properties, so
+    # has_local_auth/has_google_auth must be set explicitly to mirror the real
+    # User.has_local_auth/has_google_auth @property behavior based on provider.
+    u.has_local_auth = "local" in u.provider
+    u.has_google_auth = "google" in u.provider
+
+    def _add_provider(p: str) -> None:
+        if p not in u.provider:
+            u.provider.append(p)
+        if p == "google":
+            u.has_google_auth = True
+        elif p == "local":
+            u.has_local_auth = True
+
+    u.add_provider = MagicMock(side_effect=_add_provider)
     u.native_language = "vi"
     u.target_language = "en"
     u.level = "beginner"
@@ -53,7 +76,7 @@ def _make_mock_user(
     u.is_admin = False
     u.is_super_admin = False
     u.role_id = None
-    u.created_at = datetime.utcnow()
+    u.created_at = datetime.now(UTC)
     u.last_login = None
     u.avatar_url = None
     return u
@@ -84,7 +107,7 @@ async def fake_refresh(obj):
         if not getattr(obj, "id", None):
             obj.id = uuid.UUID("550e8400-e29b-41d4-a716-446655440002")
         if not getattr(obj, "created_at", None):
-            obj.created_at = datetime.utcnow()
+            obj.created_at = datetime.now(UTC)
         if getattr(obj, "is_active", None) is None:
             obj.is_active = True
         if getattr(obj, "is_verified", None) is None:
@@ -187,26 +210,28 @@ class TestRegister:
 
     async def test_register_success_returns_201(self, client):
         """Valid registration creates a user and returns 201."""
-        response = await client.post(
-            f"{BASE}/register",
-            json={
-                "email": "newuser@example.com",
-                "username": "newuser",
-                "password": "SecurePass123!",
-            },
-        )
+        with patch("app.routes.auth.EmailService.send_verification_email", new=AsyncMock()):
+            response = await client.post(
+                f"{BASE}/register",
+                json={
+                    "email": "newuser@example.com",
+                    "username": "newuser",
+                    "password": "SecurePass123!",
+                },
+            )
         assert response.status_code == 201
 
     async def test_register_success_response_has_email(self, client):
         """Successful register response includes submitted email."""
-        response = await client.post(
-            f"{BASE}/register",
-            json={
-                "email": "another@example.com",
-                "username": "anotheruser",
-                "password": "SecurePass123!",
-            },
-        )
+        with patch("app.routes.auth.EmailService.send_verification_email", new=AsyncMock()):
+            response = await client.post(
+                f"{BASE}/register",
+                json={
+                    "email": "another@example.com",
+                    "username": "anotheruser",
+                    "password": "SecurePass123!",
+                },
+            )
         assert response.status_code == 201
         data = response.json()
         assert data["email"] == "another@example.com"
@@ -409,6 +434,35 @@ async def test_login_missing_password_returns_422(self, client):
         )
         assert response.status_code == 422
 
+    async def test_login_unverified_user_returns_403(self):
+        """Correct credentials but unverified email returns 403, not tokens."""
+        from app.main import app
+        from app.core.database import get_db
+
+        unverified_user = _make_mock_user(is_verified=False)
+        session = _make_mock_session(scalar_one_or_none_value=unverified_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.services.auth_service.verify_password_async", new=AsyncMock(return_value=True)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/login",
+                    json={"email": "test@example.com", "password": "testpass"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+        message = response.json()["error"]["message"].lower()
+        assert "not verified" in message
+        data = response.json()
+        assert "access_token" not in data
+        assert "refresh_token" not in data
+
 
 # ===========================================================================
 # POST /auth/refresh
@@ -481,6 +535,35 @@ async def test_refresh_user_not_found_returns_401(self, client):
             )
         assert response.status_code == 401
 
+    async def test_refresh_unverified_user_returns_403(self):
+        """A still-unverified user cannot use a refresh token to renew access either."""
+        from app.main import app
+        from app.core.database import get_db
+
+        unverified_user = _make_mock_user(is_verified=False)
+        session = _make_mock_session(scalar_one_or_none_value=unverified_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch(
+            "app.core.security.decode_token",
+            return_value={"type": "refresh", "sub": "00000000-0000-0000-0000-000000000001"},
+        ):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/refresh",
+                    json={"refresh_token": "valid.refresh.token"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+        message = response.json()["error"]["message"].lower()
+        assert "not verified" in message
+
 
 # ===========================================================================
 # GET /auth/me
@@ -519,6 +602,33 @@ async def test_logout_response_has_message(self, client):
         assert "message" in data
         assert "Logged out" in data["message"]
 
+    async def test_logout_blacklists_bearer_access_token(self, client):
+        token = create_access_token({"sub": "550e8400-e29b-41d4-a716-446655440001"})
+
+        with patch("app.routes.auth.TokenBlacklist.add", new=AsyncMock(return_value=True)) as add:
+            response = await client.post(
+                f"{BASE}/logout",
+                json={},
+                headers={"Authorization": f"Bearer {token}"},
+            )
+
+        assert response.status_code == 200
+        add.assert_awaited_once()
+
+    async def test_blacklisted_access_token_is_rejected(self, client):
+        token = create_access_token({"sub": "550e8400-e29b-41d4-a716-446655440001"})
+
+        with patch(
+            "app.core.dependencies.TokenBlacklist.is_blacklisted",
+            new=AsyncMock(return_value=True),
+        ):
+            response = await client.get(
+                f"{BASE}/me",
+                headers={"Authorization": f"Bearer {token}"},
+            )
+
+        assert response.status_code == 401
+
 
 # ===========================================================================
 # POST /auth/forgot-password
@@ -557,7 +667,8 @@ async def mock_get_db():
         app.dependency_overrides[get_db] = mock_get_db
         transport = ASGITransport(app=app)
 
-        with patch("app.core.security.create_verification_token", return_value="fake-token"):
+        with patch("app.core.security.create_verification_token", return_value="fake-token"), \
+             patch("app.routes.auth.EmailService.send_password_reset_email", new=AsyncMock()):
             async with AsyncClient(transport=transport, base_url="http://test") as c:
                 response = await c.post(
                     f"{BASE}/forgot-password",
@@ -698,3 +809,549 @@ async def mock_get_db():
         data = response.json()
         assert data["verified"] is True
         assert "already verified" in data["message"].lower()
+
+
+# ===========================================================================
+# POST /auth/google
+# ===========================================================================
+
+class TestGoogleLogin:
+
+    async def test_google_login_invalid_token_returns_401(self, client):
+        """An unverifiable Google ID token returns 401."""
+        with patch("app.core.security.verify_google_token", new=AsyncMock(return_value=None)), \
+             patch("app.core.firebase_auth.verify_firebase_token", return_value=None):
+            response = await client.post(
+                f"{BASE}/google",
+                json={"id_token": "bad-token", "source": "app"},
+            )
+        assert response.status_code == 401
+
+    async def test_google_login_new_user_created_returns_200(self):
+        """A first-time Google sign-in (email_verified=True) creates a new user."""
+        from app.main import app
+        from app.core.database import get_db
+
+        session = _make_mock_session(scalar_one_or_none_value=None)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        google_info = {"email": "newgoogle@example.com", "email_verified": True, "name": "New Google User"}
+        with patch("app.core.security.verify_google_token", new=AsyncMock(return_value=google_info)), \
+             patch("app.routes.auth._ensure_unique_username", new=AsyncMock(return_value="newgoogleuser")), \
+             patch("app.routes.auth._get_role_id", new=AsyncMock(return_value=None)), \
+             patch(
+                 "app.services.starter_reward_service.StarterRewardService.grant_new_user_reward",
+                 new=AsyncMock(),
+             ):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/google",
+                    json={"id_token": "good-token", "source": "app"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
+        data = response.json()
+        assert "access_token" in data
+
+    async def test_google_login_links_unverified_local_account_when_email_verified(self):
+        """Google vouching for the email (email_verified=True) verifies and links
+        an existing unverified local-only account instead of blocking it (Phase 2.2)."""
+        from app.main import app
+        from app.core.database import get_db
+
+        local_user = _make_mock_user(is_verified=False, provider=["local"])
+        session = _make_mock_session(scalar_one_or_none_value=local_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        google_info = {"email": "test@example.com", "email_verified": True, "name": "Test User"}
+        with patch("app.core.security.verify_google_token", new=AsyncMock(return_value=google_info)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/google",
+                    json={"id_token": "good-token", "source": "app"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
+        data = response.json()
+        assert "access_token" in data
+        assert local_user.is_verified is True
+        assert "google" in local_user.provider
+
+    async def test_google_login_local_account_blocked_when_email_not_verified(self):
+        """If Google has NOT verified the email, an unverified local account stays blocked."""
+        from app.main import app
+        from app.core.database import get_db
+
+        local_user = _make_mock_user(is_verified=False, provider=["local"])
+        session = _make_mock_session(scalar_one_or_none_value=local_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        google_info = {"email": "test@example.com", "email_verified": False, "name": "Test User"}
+        with patch("app.core.security.verify_google_token", new=AsyncMock(return_value=google_info)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/google",
+                    json={"id_token": "good-token", "source": "app"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 400
+
+    async def test_google_login_admin_source_not_allowlisted_new_user_returns_403(self):
+        """Admin-source Google login for a brand-new, non-allowlisted email is rejected."""
+        from app.main import app
+        from app.core.database import get_db
+
+        session = _make_mock_session(scalar_one_or_none_value=None)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        google_info = {"email": "stranger@example.com", "email_verified": True, "name": "Stranger"}
+        with patch("app.core.security.verify_google_token", new=AsyncMock(return_value=google_info)), \
+             patch("app.core.config.settings.GOOGLE_ADMIN_CLIENT_ID", "admin-client-id"), \
+             patch("app.core.config.Settings.get_admin_role_for_email", return_value=None):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/google",
+                    json={"id_token": "good-token", "source": "admin"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+
+
+# ===========================================================================
+# POST /auth/facebook
+# ===========================================================================
+
+class TestFacebookLogin:
+
+    async def test_facebook_login_invalid_token_returns_401(self, client):
+        """An unverifiable Firebase ID token returns 401."""
+        with patch("app.core.firebase_auth.verify_firebase_token", return_value=None):
+            response = await client.post(
+                f"{BASE}/facebook",
+                json={"id_token": "bad-token", "source": "app"},
+            )
+        assert response.status_code == 401
+
+    async def test_facebook_login_success_returns_200(self, client):
+        """A valid Facebook (Firebase) token returns tokens for an active user."""
+        fb_user = _make_mock_user(is_active=True)
+        claims = {
+            "email": fb_user.email,
+            "email_verified": True,
+            "firebase": {"sign_in_provider": "facebook.com"},
+        }
+        with patch("app.core.firebase_auth.verify_firebase_token", return_value=claims), \
+             patch("app.core.firebase_auth.get_or_create_user_from_claims", new=AsyncMock(return_value=fb_user)):
+            response = await client.post(
+                f"{BASE}/facebook",
+                json={"id_token": "good-token", "source": "app"},
+            )
+        assert response.status_code == 200
+        data = response.json()
+        assert "access_token" in data
+
+    async def test_facebook_login_inactive_user_returns_403(self, client):
+        """An inactive account cannot complete Facebook login."""
+        fb_user = _make_mock_user(is_active=False)
+        claims = {
+            "email": fb_user.email,
+            "email_verified": True,
+            "firebase": {"sign_in_provider": "facebook.com"},
+        }
+        with patch("app.core.firebase_auth.verify_firebase_token", return_value=claims), \
+             patch("app.core.firebase_auth.get_or_create_user_from_claims", new=AsyncMock(return_value=fb_user)):
+            response = await client.post(
+                f"{BASE}/facebook",
+                json={"id_token": "good-token", "source": "app"},
+            )
+        assert response.status_code == 403
+
+
+# ===========================================================================
+# POST /auth/admin/login
+# ===========================================================================
+
+class TestAdminLogin:
+
+    def _admin_user(self, *, is_active=True, is_verified=True, role_level=1):
+        user = _make_mock_user(is_active=is_active, is_verified=is_verified)
+        user.role_level = role_level
+        return user
+
+    async def test_admin_login_success_returns_200_with_tokens(self):
+        from app.main import app
+        from app.core.database import get_db
+
+        admin_user = self._admin_user()
+        session = _make_mock_session(scalar_one_or_none_value=admin_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=True)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/admin/login",
+                    json={"email": "admin@example.com", "password": "testpass"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
+        assert "access_token" in response.json()["data"]
+
+    async def test_admin_login_insufficient_role_returns_403(self):
+        from app.main import app
+        from app.core.database import get_db
+
+        regular_user = self._admin_user(role_level=0)
+        session = _make_mock_session(scalar_one_or_none_value=regular_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=True)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/admin/login",
+                    json={"email": "user@example.com", "password": "testpass"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+        assert "Admin privileges" in response.json()["error"]["message"]
+
+    async def test_admin_login_unverified_returns_403(self):
+        """An admin account that hasn't verified its email cannot log in (Phase 2.1)."""
+        from app.main import app
+        from app.core.database import get_db
+
+        admin_user = self._admin_user(is_verified=False)
+        session = _make_mock_session(scalar_one_or_none_value=admin_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=True)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/admin/login",
+                    json={"email": "admin@example.com", "password": "testpass"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+        assert "not verified" in response.json()["error"]["message"].lower()
+
+    async def test_admin_login_inactive_returns_403(self):
+        from app.main import app
+        from app.core.database import get_db
+
+        admin_user = self._admin_user(is_active=False)
+        session = _make_mock_session(scalar_one_or_none_value=admin_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=True)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/admin/login",
+                    json={"email": "admin@example.com", "password": "testpass"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+        assert "inactive" in response.json()["error"]["message"].lower()
+
+    async def test_admin_login_wrong_password_returns_401(self):
+        from app.main import app
+        from app.core.database import get_db
+
+        admin_user = self._admin_user()
+        session = _make_mock_session(scalar_one_or_none_value=admin_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=False)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/admin/login",
+                    json={"email": "admin@example.com", "password": "wrongpass"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 401
+
+
+# ===========================================================================
+# POST /auth/admin/request-otp, /auth/admin/verify-otp
+# ===========================================================================
+
+class TestAdminOtp:
+
+    async def test_request_otp_unknown_email_still_200(self, client):
+        """Anti-enumeration: unknown email returns 200 same as a real admin."""
+        response = await client.post(
+            f"{BASE}/admin/request-otp",
+            json={"email": "ghost@example.com"},
+        )
+        assert response.status_code == 200
+
+    async def test_request_otp_requires_redis_in_production(self, client, monkeypatch):
+        monkeypatch.setattr("app.routes.auth.settings.APP_ENV", "production")
+
+        with patch(
+            "app.routes.auth.RedisClient.get_instance",
+            new=AsyncMock(return_value=None),
+        ):
+            response = await client.post(
+                f"{BASE}/admin/request-otp",
+                json={"email": "ghost@example.com"},
+            )
+
+        assert response.status_code == 503
+
+    async def test_request_otp_unverified_admin_still_200_but_no_otp_sent(self):
+        """An unverified admin gets the same generic 200 response (Phase 2.1), but no
+        OTP is actually generated for them — verified implicitly via verify-otp failing."""
+        from app.main import app
+        from app.core.database import get_db
+        from app.routes import auth as auth_routes
+
+        unverified_admin = _make_mock_user(is_verified=False)
+        unverified_admin.role_level = 1
+        session = _make_mock_session(scalar_one_or_none_value=unverified_admin)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        auth_routes._admin_otp_store.clear()
+        transport = ASGITransport(app=app)
+
+        async with AsyncClient(transport=transport, base_url="http://test") as c:
+            response = await c.post(
+                f"{BASE}/admin/request-otp",
+                json={"email": unverified_admin.email},
+            )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
+        assert unverified_admin.email not in auth_routes._admin_otp_store
+
+    async def test_verify_otp_invalid_code_returns_400(self, client):
+        response = await client.post(
+            f"{BASE}/admin/verify-otp",
+            json={"email": "admin@example.com", "otp": "000000"},
+        )
+        assert response.status_code == 400
+
+    async def test_verify_otp_unverified_admin_returns_403(self):
+        """A valid OTP cannot bypass the is_verified check on verify-otp (Phase 2.1)."""
+        from app.main import app
+        from app.core.database import get_db
+        from app.routes import auth as auth_routes
+        import time
+
+        unverified_admin = _make_mock_user(is_verified=False)
+        unverified_admin.role_level = 1
+        session = _make_mock_session(scalar_one_or_none_value=unverified_admin)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        auth_routes._admin_otp_store[unverified_admin.email] = ("123456", time.time() + 300)
+        transport = ASGITransport(app=app)
+
+        async with AsyncClient(transport=transport, base_url="http://test") as c:
+            response = await c.post(
+                f"{BASE}/admin/verify-otp",
+                json={"email": unverified_admin.email, "otp": "123456"},
+            )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 403
+
+    async def test_verify_otp_success_returns_tokens(self):
+        from app.main import app
+        from app.core.database import get_db
+        from app.routes import auth as auth_routes
+        import time
+
+        admin_user = _make_mock_user(is_verified=True)
+        admin_user.role_level = 1
+        session = _make_mock_session(scalar_one_or_none_value=admin_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        auth_routes._admin_otp_store[admin_user.email] = ("654321", time.time() + 300)
+        transport = ASGITransport(app=app)
+
+        async with AsyncClient(transport=transport, base_url="http://test") as c:
+            response = await c.post(
+                f"{BASE}/admin/verify-otp",
+                json={"email": admin_user.email, "otp": "654321"},
+            )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
+        assert "access_token" in response.json()["data"]
+
+
+# ===========================================================================
+# POST /auth/change-password
+# ===========================================================================
+
+class TestChangePassword:
+
+    async def test_change_password_success_returns_200(self, auth_client):
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=True)):
+            response = await auth_client.post(
+                f"{BASE}/change-password",
+                json={"current_password": "oldpass123", "new_password": "newpass456"},
+            )
+        assert response.status_code == 200
+
+    async def test_change_password_wrong_current_password_returns_400(self, auth_client):
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=False)):
+            response = await auth_client.post(
+                f"{BASE}/change-password",
+                json={"current_password": "wrongpass", "new_password": "newpass456"},
+            )
+        assert response.status_code == 400
+        assert "incorrect" in response.json()["error"]["message"].lower()
+
+    async def test_change_password_oauth_only_account_returns_400(self):
+        """An OAuth-only account (no 'local' provider) cannot change a password it doesn't have."""
+        from app.main import app
+        from app.core.database import get_db
+        from app.core.dependencies import get_current_user
+
+        oauth_user = _make_mock_user(provider=["google"])
+        session = _make_mock_session()
+
+        async def mock_get_db():
+            yield session
+
+        async def mock_get_current_user():
+            return oauth_user
+
+        app.dependency_overrides[get_db] = mock_get_db
+        app.dependency_overrides[get_current_user] = mock_get_current_user
+        transport = ASGITransport(app=app)
+
+        with patch("app.routes.auth.verify_password_async", new=AsyncMock(return_value=True)):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/change-password",
+                    json={"current_password": "whatever", "new_password": "newpass456"},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 400
+        assert "OAuth" in response.json()["error"]["message"]
+
+
+# ===========================================================================
+# POST /auth/resend-verification
+# ===========================================================================
+
+class TestResendVerification:
+
+    async def test_resend_verification_unknown_email_still_200(self, client):
+        """Anti-enumeration: unknown email returns the same generic 200."""
+        response = await client.post(
+            f"{BASE}/resend-verification",
+            json={"email": "ghost@example.com"},
+        )
+        assert response.status_code == 200
+
+    async def test_resend_verification_unverified_user_returns_200(self):
+        from app.main import app
+        from app.core.database import get_db
+
+        unverified_user = _make_mock_user(is_verified=False)
+        session = _make_mock_session(scalar_one_or_none_value=unverified_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        with patch("app.core.security.create_verification_token", return_value="fake-token"), \
+             patch("app.services.email_service.EmailService.send_verification_email", new=AsyncMock()):
+            async with AsyncClient(transport=transport, base_url="http://test") as c:
+                response = await c.post(
+                    f"{BASE}/resend-verification",
+                    json={"email": unverified_user.email},
+                )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
+
+    async def test_resend_verification_already_verified_user_returns_200(self):
+        """Already-verified users get the same generic response (no email sent)."""
+        from app.main import app
+        from app.core.database import get_db
+
+        verified_user = _make_mock_user(is_verified=True)
+        session = _make_mock_session(scalar_one_or_none_value=verified_user)
+
+        async def mock_get_db():
+            yield session
+
+        app.dependency_overrides[get_db] = mock_get_db
+        transport = ASGITransport(app=app)
+
+        async with AsyncClient(transport=transport, base_url="http://test") as c:
+            response = await c.post(
+                f"{BASE}/resend-verification",
+                json={"email": verified_user.email},
+            )
+        app.dependency_overrides.clear()
+
+        assert response.status_code == 200
diff --git a/backend-service/tests/test_books_routes.py b/backend-service/tests/test_books_routes.py
index dab3d5b2..84c27c96 100644
--- a/backend-service/tests/test_books_routes.py
+++ b/backend-service/tests/test_books_routes.py
@@ -576,6 +576,60 @@ async def test_cache_key_includes_book_id_and_chapter(self, no_db_client: AsyncC
         call_kwargs = mock_cache.get_or_fetch.call_args.kwargs
         assert call_kwargs["cache_key"] == "books:quiz:gutenberg-1342:ch:5"
 
+    def test_contextual_generator_uses_chapter_excerpt(self):
+        from app.routes.books import _generate_contextual_book_quiz
+
+        quiz = _generate_contextual_book_quiz(
+            book_id="gutenberg-11",
+            chapter=2,
+            book_title="Alice's Adventures in Wonderland",
+            cefr_level="A2",
+            chapter_text=(
+                "Alice felt curious as she followed the strange rabbit. "
+                "The journey became more confusing when the hallway changed again."
+            ),
+        )
+
+        assert quiz["is_stub"] is False
+        assert quiz["source"] == "chapter_excerpt"
+        assert quiz["generator"] == "lexilingo-contextual-quiz-v1"
+        assert len(quiz["questions"]) == 3
+        assert quiz["questions"][0]["correct_index"] == 0
+        assert quiz["questions"][1]["options"][0] in {"followed", "curious", "strange"}
+
+    @pytest.mark.asyncio
+    async def test_contextual_route_cache_key_includes_context_hash(self, no_db_client: AsyncClient):
+        async def call_fetch(**kwargs):
+            data = await kwargs["fetch_fn"]()
+            mock_result = MagicMock()
+            mock_result.data = data
+            mock_result.source = "fresh"
+            mock_result.is_stale = False
+            return mock_result
+
+        with patch("app.routes.books.APICacheService") as MockCache:
+            mock_cache = AsyncMock()
+            mock_cache.get_or_fetch.side_effect = call_fetch
+            MockCache.return_value = mock_cache
+
+            response = await no_db_client.get(
+                f"{BASE}/gutenberg-11/quiz",
+                params={
+                    "chapter": "2",
+                    "book_title": "Alice's Adventures in Wonderland",
+                    "cefr_level": "A2",
+                    "chapter_text": "Alice followed a curious rabbit into a strange hallway.",
+                },
+            )
+
+        assert response.status_code == 200
+        data = response.json()
+        assert data["is_stub"] is False
+        assert data["source"] == "chapter_excerpt"
+        assert data["book_id"] == "gutenberg-11"
+        call_kwargs = mock_cache.get_or_fetch.call_args.kwargs
+        assert call_kwargs["cache_key"].startswith("books:quiz:gutenberg-11:ch:2:ctx:")
+
 
 # ============================================================================
 # Integration Tests — _fetch_books internal function
@@ -776,4 +830,3 @@ async def test_proxy_text_success(self, no_db_client: AsyncClient):
         assert response.content == b"Chapter 1: Once upon a time..."
         assert response.headers["content-type"] == "text/plain; charset=utf-8"
         assert "max-age=86400" in response.headers["cache-control"]
-
diff --git a/backend-service/tests/test_content_agent_validation.py b/backend-service/tests/test_content_agent_validation.py
index 3bb45b64..a5ee63f9 100644
--- a/backend-service/tests/test_content_agent_validation.py
+++ b/backend-service/tests/test_content_agent_validation.py
@@ -160,6 +160,63 @@ def test_invalid_course_level_is_blocking() -> None:
     assert "INVALID_COURSE_LEVEL" in codes
 
 
+def test_courses_must_be_a_list_without_crashing() -> None:
+    art = _base_artifact()
+    art["courses"] = "not-a-list"
+    report = validate_artifact(art)
+    codes = {e.code for e in report.blocking_errors}
+    assert "COURSES_TYPE" in codes
+    assert report.metrics["course_count"] == 0
+
+
+def test_course_and_child_entries_must_be_objects_without_crashing() -> None:
+    art = _base_artifact()
+    art["courses"] = [
+        "not-a-course",
+        {
+            "title": "Broken course",
+            "level": "A1",
+            "units": [
+                "not-a-unit",
+                {
+                    "title": "Broken unit",
+                    "order_index": 0,
+                    "lessons": [
+                        "not-a-lesson",
+                        {
+                            "title": "Broken lesson",
+                            "order_index": 0,
+                            "vocabulary": ["not-vocabulary"],
+                            "exercises": ["not-exercise"],
+                        },
+                    ],
+                },
+            ],
+        },
+    ]
+    report = validate_artifact(art)
+    codes = {e.code for e in report.blocking_errors}
+    assert {
+        "COURSE_ENTRY_TYPE",
+        "UNIT_ENTRY_TYPE",
+        "LESSON_ENTRY_TYPE",
+        "VOCABULARY_ENTRY_TYPE",
+        "EXERCISE_ENTRY_TYPE",
+    }.issubset(codes)
+
+
+def test_empty_units_and_lessons_are_blocking() -> None:
+    art = _base_artifact()
+    art["courses"][0]["units"] = []
+    report = validate_artifact(art)
+    assert "NO_UNITS" in {error.code for error in report.blocking_errors}
+
+    art = _base_artifact()
+    art["courses"][0]["units"][0]["lessons"] = []
+    report = validate_artifact(art)
+    assert "NO_LESSONS" in {error.code for error in report.blocking_errors}
+
+
 # --- license gate ---
 
 
diff --git a/backend-service/tests/test_course_categories_routes.py b/backend-service/tests/test_course_categories_routes.py
index 495ae05d..abc9b977 100644
--- a/backend-service/tests/test_course_categories_routes.py
+++ b/backend-service/tests/test_course_categories_routes.py
@@ -17,7 +17,7 @@
 
 import pytest
 import uuid
-from datetime import datetime
+from datetime import UTC, datetime
 from unittest.mock import AsyncMock, MagicMock, patch
 from httpx import AsyncClient, ASGITransport
 
@@ -125,8 +125,8 @@ def _make_mock_category(
     cat.order_index = 0
     cat.is_active = True
     cat.course_count = 5
-    cat.created_at = datetime.utcnow()
-    cat.updated_at = datetime.utcnow()
+    cat.created_at = datetime.now(UTC)
+    cat.updated_at = datetime.now(UTC)
     return cat
 
 
diff --git a/backend-service/tests/test_courses_routes.py b/backend-service/tests/test_courses_routes.py
index aa15d1c5..4560a42b 100644
--- a/backend-service/tests/test_courses_routes.py
+++ b/backend-service/tests/test_courses_routes.py
@@ -11,6 +11,7 @@
 
 import pytest
 import uuid
+from datetime import UTC, datetime
 from unittest.mock import AsyncMock, MagicMock, patch
 from httpx import AsyncClient, ASGITransport
 
@@ -314,11 +315,10 @@ async def test_already_enrolled_returns_200_with_message(self, auth_client: Asyn
 
     @pytest.mark.asyncio
     async def test_new_enrollment_returns_200_with_success_message(self, auth_client: AsyncClient):
-        from datetime import datetime
         mock_course = MagicMock()
         mock_course.is_published = True
         mock_progress = MagicMock()
-        mock_progress.started_at = datetime.utcnow()
+        mock_progress.started_at = datetime.now(UTC)
 
         with patch("app.crud.course.CourseCRUD.get_course", new=AsyncMock(return_value=mock_course)), \
              patch("app.crud.course.CourseCRUD.is_user_enrolled", new=AsyncMock(return_value=False)), \
diff --git a/backend-service/tests/test_devices_routes.py b/backend-service/tests/test_devices_routes.py
index 06430c9d..bf06a6d2 100644
--- a/backend-service/tests/test_devices_routes.py
+++ b/backend-service/tests/test_devices_routes.py
@@ -12,7 +12,7 @@
 """
 
 import pytest
-from datetime import datetime
+from datetime import UTC, datetime
 from unittest.mock import AsyncMock, MagicMock
 from httpx import AsyncClient, ASGITransport
 
@@ -109,8 +109,8 @@ def _make_mock_device():
     device.device_type = "android"
     device.device_name = "Pixel 8"
     device.fcm_token = "mock-fcm-token-xyz"
-    device.last_active = datetime.utcnow()
-    device.created_at = datetime.utcnow()
+    device.last_active = datetime.now(UTC)
+    device.created_at = datetime.now(UTC)
     return device
 
 
@@ -145,7 +145,7 @@ async def refresh_side_effect(obj):
                 import uuid as _uuid
                 obj.id = _uuid.uuid4()
             if not getattr(obj, "created_at", None) or str(type(obj.created_at)) == "<class 'unittest.mock.MagicMock'>":
-                obj.created_at = datetime.utcnow()
+                obj.created_at = datetime.now(UTC)
 
         mock_session.refresh = AsyncMock(side_effect=refresh_side_effect)
 
diff --git a/backend-service/tests/test_games_routes.py b/backend-service/tests/test_games_routes.py
index d6fbb550..efcd1974 100644
--- a/backend-service/tests/test_games_routes.py
+++ b/backend-service/tests/test_games_routes.py
@@ -493,6 +493,10 @@ async def test_completes_session_with_server_verified_score(self):
             new_callable=AsyncMock,
             return_value=xp_result,
         ) as award_mock, patch(
+            "app.routes.games.ItemEffectsService.get_xp_multiplier",
+            new_callable=AsyncMock,
+            return_value=1.0,
+        ) as multiplier_mock, patch(
             "app.routes.games.check_achievements_for_user",
             new_callable=AsyncMock,
             return_value=[],
@@ -519,9 +523,11 @@ async def test_completes_session_with_server_verified_score(self):
         assert session.completed_at is not None
         assert session.xp_awarded is True
         db.commit.assert_awaited_once()
+        multiplier_mock.assert_awaited_once_with(user_id)
         award_mock.assert_awaited_once()
         assert award_mock.await_args.kwargs["source_id"] == str(session_id)
         assert award_mock.await_args.kwargs["commit"] is False
+        assert award_mock.await_args.kwargs["item_multiplier"] == 1.0
         achievement_mock.assert_awaited_once_with(
             db,
             user_id,
diff --git a/backend-service/tests/test_item_effects_game_powerups.py b/backend-service/tests/test_item_effects_game_powerups.py
new file mode 100644
index 00000000..5140fad6
--- /dev/null
+++ b/backend-service/tests/test_item_effects_game_powerups.py
@@ -0,0 +1,79 @@
+"""Tests for the generic instant-consumable handler covering game power-up items."""
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.shop_catalog import GAME_POWERUP_ITEM_TYPES
+from app.models.gamification import ShopItem, UserInventory
+from app.models.user import User
+from app.services.item_effects_service import ItemEffectsService
+
+
+async def _give_item(
+    db_session: AsyncSession,
+    user: User,
+    item_type: str,
+    effects: dict,
+    quantity: int = 1,
+) -> UserInventory:
+    shop_item = ShopItem(
+        name=f"Test {item_type}",
+        description="test item",
+        item_type=item_type,
+        price_gems=10,
+        effects=effects,
+        is_available=True,
+    )
+    db_session.add(shop_item)
+    await db_session.flush()
+
+    inventory = UserInventory(
+        user_id=user.id,
+        shop_item_id=shop_item.id,
+        quantity=quantity,
+    )
+    db_session.add(inventory)
+    await db_session.commit()
+    return inventory
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("item_type", GAME_POWERUP_ITEM_TYPES)
+async def test_instant_game_powerup_consumes_one_and_echoes_effects(
+    db_session: AsyncSession,
+    test_user: User,
+    item_type: str,
+):
+    effects = {"seconds": 10} if "time" in item_type else {"chance": 0.3}
+    inventory = await _give_item(db_session, test_user, item_type, effects, quantity=2)
+
+    service = ItemEffectsService(db_session)
+    success, message, applied_effects = await service.use_item(test_user.id, inventory.id)
+
+    assert success is True
+    assert message
+    assert applied_effects["item_type"] == item_type
+    for key, value in effects.items():
+        assert applied_effects[key] == value
+
+    await db_session.refresh(inventory)
+    assert inventory.quantity == 1
+    # Instant power-ups have no duration_hours, so they never become a
+    # timed "active boost" like double_xp does.
+    assert inventory.is_active is False
+    assert inventory.expires_at is None
+
+
+@pytest.mark.asyncio
+async def test_instant_game_powerup_rejects_when_out_of_stock(
+    db_session: AsyncSession,
+    test_user: User,
+):
+    inventory = await _give_item(db_session, test_user, "skip_token", {}, quantity=0)
+
+    service = ItemEffectsService(db_session)
+    success, message, applied_effects = await service.use_item(test_user.id, inventory.id)
+
+    assert success is False
+    assert applied_effects is None
+    assert "remaining" in message.lower()
diff --git a/backend-service/tests/test_item_effects_service.py b/backend-service/tests/test_item_effects_service.py
index b99e8ace..f14ae62f 100644
--- a/backend-service/tests/test_item_effects_service.py
+++ b/backend-service/tests/test_item_effects_service.py
@@ -1,10 +1,16 @@
 from types import SimpleNamespace
-from unittest.mock import AsyncMock
+from unittest.mock import AsyncMock, MagicMock, patch
 from uuid import uuid4
 
 import pytest
 
-from app.services.item_effects_service import ItemEffectsService
+from app.services.item_effects_service import DailyChallengeService, ItemEffectsService
+
+
+def _result(value=None):
+    result = MagicMock()
+    result.scalar_one_or_none.return_value = value
+    return result
 
 
 @pytest.mark.asyncio
@@ -25,6 +31,23 @@ async def test_hint_pack_adds_bonus_hints_to_active_attempt():
     assert effects["hints_remaining"] == 7
 
 
+@pytest.mark.asyncio
+async def test_hint_pack_handles_null_bonus_hints():
+    service = ItemEffectsService(AsyncMock())
+    attempt = SimpleNamespace(bonus_hints=None, hints_used=None)
+    service._get_active_lesson_attempt = AsyncMock(return_value=attempt)
+
+    success, _, effects = await service._handle_hint_pack(
+        uuid4(),
+        SimpleNamespace(),
+        SimpleNamespace(effects={"quantity": 2}),
+    )
+
+    assert success is True
+    assert attempt.bonus_hints == 2
+    assert effects["hints_remaining"] == 5
+
+
 @pytest.mark.asyncio
 async def test_hint_pack_requires_active_attempt():
     service = ItemEffectsService(AsyncMock())
@@ -56,3 +79,101 @@ async def test_heart_refill_restores_configured_maximum():
     assert success is True
     assert attempt.lives_remaining == 3
     assert effects["hearts_restored"] == 3
+
+
+@pytest.mark.asyncio
+async def test_generic_use_rejects_cosmetic_without_consuming_inventory():
+    inventory = SimpleNamespace(
+        id=uuid4(),
+        user_id=uuid4(),
+        shop_item_id=uuid4(),
+        quantity=1,
+    )
+    shop_item = SimpleNamespace(
+        id=inventory.shop_item_id,
+        item_type="avatar",
+        name="Sunny Avatar",
+        effects={"avatar_url": "https://example.com/avatar.svg"},
+    )
+    db = MagicMock()
+    db.execute = AsyncMock(side_effect=[_result(inventory), _result(shop_item)])
+    db.commit = AsyncMock()
+
+    service = ItemEffectsService(db)
+    success, message, effects = await service.use_item(
+        inventory.user_id,
+        inventory.id,
+    )
+
+    assert success is False
+    assert "dedicated inventory endpoint" in message
+    assert effects is None
+    assert inventory.quantity == 1
+    db.commit.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_daily_challenge_service_rejects_duplicate_claim():
+    db = MagicMock()
+    db.execute = AsyncMock(return_value=_result(SimpleNamespace()))
+    db.add = MagicMock()
+    db.commit = AsyncMock()
+
+    service = DailyChallengeService(db)
+    success, message, payload = await service.claim_challenge_reward(
+        user_id=uuid4(),
+        challenge_id="complete_lessons",
+        xp_reward=20,
+    )
+
+    assert success is False
+    assert "already claimed" in message.lower()
+    assert payload["already_claimed"] is True
+    db.add.assert_not_called()
+    db.commit.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_daily_challenge_service_records_claim_and_commits_once():
+    user_id = uuid4()
+    user = SimpleNamespace(id=user_id, total_xp=5)
+    db = MagicMock()
+    db.execute = AsyncMock(
+        side_effect=[
+            _result(None),
+            _result(user),
+            _result(None),
+        ]
+    )
+    db.add = MagicMock()
+    db.commit = AsyncMock()
+    db.rollback = AsyncMock()
+
+    service = DailyChallengeService(db)
+    with patch(
+        "app.crud.gamification.LeaderboardCRUD.add_xp",
+        new=AsyncMock(),
+    ) as add_xp, patch(
+        "app.crud.gamification.WalletCRUD.add_gems",
+        new=AsyncMock(),
+    ) as add_gems:
+        success, message, payload = await service.claim_challenge_reward(
+            user_id=user_id,
+            challenge_id="complete_lessons",
+            xp_reward=20,
+            gems_reward=3,
+        )
+
+    added_model_names = [call.args[0].__class__.__name__ for call in db.add.call_args_list]
+
+    assert success is True
+    assert "Claimed" in message
+    assert payload["xp_earned"] == 20
+    assert payload["gems_earned"] == 3
+    assert user.total_xp == 25
+    assert "DailyActivity" in added_model_names
+    assert "ChallengeRewardClaim" in added_model_names
+    add_xp.assert_awaited_once_with(db, user_id, 20)
+    add_gems.assert_awaited_once()
+    assert add_gems.await_args.kwargs["commit"] is False
+    db.commit.assert_awaited_once()
diff --git a/backend-service/tests/test_learning_routes.py b/backend-service/tests/test_learning_routes.py
index 14191b50..8bef1f8e 100644
--- a/backend-service/tests/test_learning_routes.py
+++ b/backend-service/tests/test_learning_routes.py
@@ -7,7 +7,7 @@
 from httpx import AsyncClient
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
-from datetime import datetime
+from datetime import UTC, datetime
 
 from app.models.course import Course, Unit, Lesson
 from app.models.user import User
@@ -85,7 +85,7 @@ async def test_start_lesson_resume_existing(
         existing_attempt = LessonAttempt(
             user_id=test_user.id,
             lesson_id=test_lesson.id,
-            started_at=datetime.utcnow(),
+            started_at=datetime.now(UTC),
             total_questions=10,
             lives_remaining=2,
             hints_used=1,
@@ -124,6 +124,37 @@ async def test_start_lesson_not_found(
         )
         
         assert response.status_code == 404
+
+    async def test_start_lesson_missing_exercises_rejected_in_production(
+        self,
+        async_client: AsyncClient,
+        db_session: AsyncSession,
+        auth_headers: dict,
+        test_course: Course,
+        test_unit: Unit,
+        monkeypatch,
+    ):
+        """Production should not silently serve demo exercises for empty lessons."""
+        lesson = Lesson(
+            course_id=test_course.id,
+            unit_id=test_unit.id,
+            title="Empty Lesson",
+            description="Missing content",
+            order_index=99,
+            lesson_type="vocabulary",
+            content={},
+        )
+        db_session.add(lesson)
+        await db_session.commit()
+        await db_session.refresh(lesson)
+        monkeypatch.setattr("app.routes.learning.settings.APP_ENV", "production")
+
+        response = await async_client.post(
+            f"/api/v1/learning/lessons/{lesson.id}/start",
+            headers=auth_headers,
+        )
+
+        assert response.status_code == 409
     
     async def test_submit_answer_correct(
         self,
@@ -320,7 +351,7 @@ async def test_complete_lesson_already_completed(
         test_lesson_attempt: LessonAttempt
     ):
         """Test cannot complete already completed lesson"""
-        test_lesson_attempt.finished_at = datetime.utcnow()
+        test_lesson_attempt.finished_at = datetime.now(UTC)
         await db_session.commit()
         
         response = await async_client.post(
diff --git a/backend-service/tests/test_mistakes_routes.py b/backend-service/tests/test_mistakes_routes.py
new file mode 100644
index 00000000..f20c68c6
--- /dev/null
+++ b/backend-service/tests/test_mistakes_routes.py
@@ -0,0 +1,230 @@
+"""Tests for synced mistake notebook API routes."""
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.security import create_access_token
+from app.models.user import User
+
+
+def _payload(**overrides):
+    data = {
+        "id": "mistake_news_001",
+        "source_type": "news_quiz",
+        "source_id": "article_123",
+        "source_title": "Solar Panels Power Local School",
+        "question": "What is the main idea of the article?",
+        "selected_answer": "The school cancelled the project",
+        "correct_answer": "The school installed solar panels",
+        "explanation": "The article focuses on a renewable energy project.",
+        "skill": "reading",
+        "metadata": {"question_id": "q1"},
+    }
+    data.update(overrides)
+    return data
+
+
+@pytest.mark.asyncio
+async def test_mistakes_require_authentication(async_client):
+    response = await async_client.get("/api/v1/mistakes")
+
+    assert response.status_code in {401, 403}
+
+
+@pytest.mark.asyncio
+async def test_create_and_list_mistake(async_client, auth_headers):
+    response = await async_client.post(
+        "/api/v1/mistakes",
+        headers=auth_headers,
+        json=_payload(),
+    )
+
+    assert response.status_code == 201
+    created = response.json()["data"]
+    assert created["id"] == "mistake_news_001"
+    assert created["status"] == "open"
+    assert created["attempt_count"] == 1
+    assert created["metadata"] == {"question_id": "q1"}
+
+    list_response = await async_client.get("/api/v1/mistakes", headers=auth_headers)
+
+    assert list_response.status_code == 200
+    entries = list_response.json()["data"]
+    assert len(entries) == 1
+    assert entries[0]["id"] == "mistake_news_001"
+
+
+@pytest.mark.asyncio
+async def test_duplicate_mistake_refreshes_existing_entry(async_client, auth_headers):
+    await async_client.post("/api/v1/mistakes", headers=auth_headers, json=_payload())
+    reviewed = await async_client.patch(
+        "/api/v1/mistakes/mistake_news_001/review",
+        headers=auth_headers,
+    )
+    assert reviewed.status_code == 200
+    assert reviewed.json()["data"]["status"] == "reviewed"
+
+    duplicate = await async_client.post(
+        "/api/v1/mistakes",
+        headers=auth_headers,
+        json=_payload(explanation="A refreshed explanation."),
+    )
+
+    assert duplicate.status_code == 201
+    data = duplicate.json()["data"]
+    assert data["id"] == "mistake_news_001"
+    assert data["status"] == "open"
+    assert data["reviewed_at"] is None
+    assert data["review_count"] == 1
+    assert data["attempt_count"] == 2
+    assert data["explanation"] == "A refreshed explanation."
+
+    list_response = await async_client.get("/api/v1/mistakes?status=all", headers=auth_headers)
+    assert len(list_response.json()["data"]) == 1
+
+
+@pytest.mark.asyncio
+async def test_duplicate_without_client_id_uses_source_question_fallback(
+    async_client,
+    auth_headers,
+):
+    payload = _payload()
+    payload.pop("id")
+
+    first = await async_client.post(
+        "/api/v1/mistakes",
+        headers=auth_headers,
+        json=payload,
+    )
+    assert first.status_code == 201
+    server_id = first.json()["data"]["id"]
+    assert server_id.startswith("mistake_") is False
+
+    duplicate = await async_client.post(
+        "/api/v1/mistakes",
+        headers=auth_headers,
+        json=_payload(
+            id=None,
+            selected_answer="Different wrong answer",
+            explanation="Fallback duplicate.",
+        ),
+    )
+    assert duplicate.status_code == 201
+    data = duplicate.json()["data"]
+    assert data["id"] == server_id
+    assert data["attempt_count"] == 2
+    assert data["selected_answer"] == "Different wrong answer"
+    assert data["explanation"] == "Fallback duplicate."
+
+    reviewed = await async_client.patch(
+        f"/api/v1/mistakes/{server_id}/review",
+        headers=auth_headers,
+    )
+    assert reviewed.status_code == 200
+    assert reviewed.json()["data"]["status"] == "reviewed"
+
+    deleted = await async_client.delete(
+        f"/api/v1/mistakes/{server_id}",
+        headers=auth_headers,
+    )
+    assert deleted.status_code == 200
+
+
+@pytest.mark.asyncio
+async def test_create_ignores_client_owned_review_state(async_client, auth_headers):
+    response = await async_client.post(
+        "/api/v1/mistakes",
+        headers=auth_headers,
+        json=_payload(
+            reviewed_at="2099-01-01T00:00:00Z",
+            review_count=999999,
+            created_at="2099-01-01T00:00:00Z",
+        ),
+    )
+
+    assert response.status_code == 201
+    data = response.json()["data"]
+    assert data["status"] == "open"
+    assert data["reviewed_at"] is None
+    assert data["review_count"] == 0
+    assert not data["created_at"].startswith("2099")
+
+
+@pytest.mark.asyncio
+async def test_review_reopen_and_delete_mistake(async_client, auth_headers):
+    await async_client.post("/api/v1/mistakes", headers=auth_headers, json=_payload())
+
+    reviewed = await async_client.patch(
+        "/api/v1/mistakes/mistake_news_001/review",
+        headers=auth_headers,
+    )
+    assert reviewed.status_code == 200
+    assert reviewed.json()["data"]["status"] == "reviewed"
+    assert reviewed.json()["data"]["review_count"] == 1
+
+    open_list = await async_client.get("/api/v1/mistakes", headers=auth_headers)
+    assert open_list.json()["data"] == []
+
+    reviewed_list = await async_client.get(
+        "/api/v1/mistakes?status=reviewed",
+        headers=auth_headers,
+    )
+    assert len(reviewed_list.json()["data"]) == 1
+
+    reopened = await async_client.patch(
+        "/api/v1/mistakes/mistake_news_001/reopen",
+        headers=auth_headers,
+    )
+    assert reopened.status_code == 200
+    assert reopened.json()["data"]["status"] == "open"
+    assert reopened.json()["data"]["reviewed_at"] is None
+
+    deleted = await async_client.delete(
+        "/api/v1/mistakes/mistake_news_001",
+        headers=auth_headers,
+    )
+    assert deleted.status_code == 200
+    assert deleted.json()["message"] == "Mistake deleted"
+
+    list_response = await async_client.get("/api/v1/mistakes?status=all", headers=auth_headers)
+    assert list_response.json()["data"] == []
+
+
+@pytest.mark.asyncio
+async def test_mistakes_are_user_isolated(
+    async_client,
+    auth_headers,
+    db_session: AsyncSession,
+):
+    await async_client.post("/api/v1/mistakes", headers=auth_headers, json=_payload())
+
+    other_user = User(
+        email="other@example.com",
+        username="otheruser",
+        hashed_password="$2b$12$LQv3c1yqBWVHxkd0LHAkCOYz6TtxMQJqhN8/LewY5GyYzS6NzE3Fu",
+        display_name="Other User",
+        is_active=True,
+        is_verified=True,
+        native_language="vi",
+        target_language="en",
+        level="beginner",
+    )
+    db_session.add(other_user)
+    await db_session.commit()
+    await db_session.refresh(other_user)
+    other_headers = {
+        "Authorization": f"Bearer {create_access_token(data={'sub': str(other_user.id)})}"
+    }
+
+    other_list = await async_client.get(
+        "/api/v1/mistakes?status=all",
+        headers=other_headers,
+    )
+    assert other_list.status_code == 200
+    assert other_list.json()["data"] == []
+
+    other_review = await async_client.patch(
+        "/api/v1/mistakes/mistake_news_001/review",
+        headers=other_headers,
+    )
+    assert other_review.status_code == 404
diff --git a/backend-service/tests/test_news_routes.py b/backend-service/tests/test_news_routes.py
index f14b4b89..5d6a8c5c 100644
--- a/backend-service/tests/test_news_routes.py
+++ b/backend-service/tests/test_news_routes.py
@@ -11,6 +11,8 @@
 
 import pytest
 from unittest.mock import AsyncMock, MagicMock, patch
+import httpx
+from fastapi import HTTPException
 from httpx import AsyncClient, ASGITransport
 
 
@@ -208,6 +210,59 @@ def test_words_are_lowercase(self):
             assert w == w.lower()
 
 
+class TestNewsUrlSafety:
+    """Tests for server-side fetch URL guard."""
+
+    @pytest.mark.parametrize(
+        "url",
+        [
+            "ftp://example.com/image.jpg",
+            "http://localhost/image.jpg",
+            "http://127.0.0.1/image.jpg",
+            "http://10.0.0.1/image.jpg",
+        ],
+    )
+    def test_rejects_non_public_urls(self, url):
+        from app.routes.news import _validate_public_http_url
+
+        with pytest.raises(HTTPException):
+            _validate_public_http_url(url)
+
+    def test_rejects_host_if_any_resolved_ip_is_private(self, monkeypatch):
+        from app.routes.news import _validate_public_http_url
+
+        def fake_getaddrinfo(*args, **kwargs):
+            return [
+                (None, None, None, "", ("93.184.216.34", 443)),
+                (None, None, None, "", ("10.0.0.1", 443)),
+            ]
+
+        monkeypatch.setattr("socket.getaddrinfo", fake_getaddrinfo)
+
+        with pytest.raises(HTTPException):
+            _validate_public_http_url("https://safe.example/image.jpg")
+
+    @pytest.mark.asyncio
+    async def test_rejects_redirect_to_private_url(self, monkeypatch):
+        from app.routes.news import _get_public_url
+
+        def fake_getaddrinfo(*args, **kwargs):
+            return [(None, None, None, "", ("93.184.216.34", 443))]
+
+        class RedirectClient:
+            async def get(self, url, **kwargs):
+                return httpx.Response(
+                    302,
+                    headers={"location": "http://127.0.0.1/private"},
+                    request=httpx.Request("GET", url),
+                )
+
+        monkeypatch.setattr("socket.getaddrinfo", fake_getaddrinfo)
+
+        with pytest.raises(HTTPException):
+            await _get_public_url(RedirectClient(), "https://safe.example/image.jpg")
+
+
 # ============================================================================
 # Route Tests — GET /news/categories
 # ============================================================================
@@ -443,7 +498,7 @@ async def test_returns_quiz_structure(self, no_db_client: AsyncClient):
 
     @pytest.mark.asyncio
     async def test_quiz_cache_key_format(self, no_db_client: AsyncClient):
-        """Cache key should be news:quiz:{article_id}"""
+        """Cache key should be versioned so stale placeholder quizzes are bypassed."""
         mock_result = MagicMock()
         mock_result.data = {"questions": [], "total_questions": 0, "xp_reward": 15}
         mock_result.source = "db"
@@ -457,7 +512,7 @@ async def test_quiz_cache_key_format(self, no_db_client: AsyncClient):
             await no_db_client.get("/api/v1/news/myArticle001/quiz")
 
         call_kwargs = mock_cache.get_or_fetch.call_args.kwargs
-        assert call_kwargs["cache_key"] == "news:quiz:myArticle001"
+        assert call_kwargs["cache_key"] == "news:quiz:v2:myArticle001"
 
     @pytest.mark.asyncio
     async def test_429_on_quota_error(self, no_db_client: AsyncClient):
@@ -482,6 +537,39 @@ async def test_429_on_quota_error(self, no_db_client: AsyncClient):
 class TestGenerateQuizStructure:
     """Tests for the quiz placeholder structure returned by _generate_quiz."""
 
+    @pytest.mark.asyncio
+    async def test_quiz_uses_article_context_when_available(self):
+        from app.routes.news import _generate_quiz
+
+        article = {
+            "title": "Solar Panels Power Local School",
+            "description": "Students learn from a new renewable energy project.",
+            "content": (
+                "A local school installed solar panels on the roof. "
+                "The project reduces electricity costs and teaches students about renewable energy. "
+                "Teachers said the panels will support science lessons throughout the year."
+            ),
+        }
+
+        quiz = await _generate_quiz("solar_school", article=article)
+
+        serialized = str(quiz).lower()
+        assert "solar" in serialized
+        assert "renewable" in serialized or "electricity" in serialized
+        assert "option a" not in serialized
+        assert "ai-generated" not in serialized
+
+    @pytest.mark.asyncio
+    async def test_quiz_falls_back_to_article_id_without_placeholders(self):
+        from app.routes.news import _generate_quiz
+
+        quiz = await _generate_quiz("climate_policy_2026")
+
+        serialized = str(quiz).lower()
+        assert "option a" not in serialized
+        assert "ai-generated" not in serialized
+        assert quiz["total_questions"] == len(quiz["questions"])
+
     @pytest.mark.asyncio
     async def test_quiz_has_5_questions(self):
         from app.routes.news import _generate_quiz
diff --git a/backend-service/tests/test_notification_reminder_routes.py b/backend-service/tests/test_notification_reminder_routes.py
index d1b5dc9d..7c025565 100644
--- a/backend-service/tests/test_notification_reminder_routes.py
+++ b/backend-service/tests/test_notification_reminder_routes.py
@@ -2,8 +2,10 @@
 
 import pytest
 from httpx import ASGITransport, AsyncClient
+from sqlalchemy import select
 
 from app.main import app
+from app.models.notification import Notification
 
 
 @pytest.mark.asyncio
@@ -21,3 +23,53 @@ async def test_authenticated_notification_and_reminder_routes_are_mounted(path):
         response = await client.get(path)
 
     assert response.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_delete_notification_removes_owned_notification(
+    async_client,
+    db_session,
+    auth_headers,
+    test_user,
+):
+    notification = Notification(
+        user_id=test_user.id,
+        title="Old notification",
+        body="Done",
+        type="system",
+    )
+    db_session.add(notification)
+    await db_session.commit()
+    await db_session.refresh(notification)
+
+    response = await async_client.delete(
+        f"/api/v1/notifications/{notification.id}",
+        headers=auth_headers,
+    )
+
+    assert response.status_code == 200
+    assert await db_session.get(Notification, notification.id) is None
+
+
+@pytest.mark.asyncio
+async def test_delete_all_notifications_removes_owned_notifications(
+    async_client,
+    db_session,
+    auth_headers,
+    test_user,
+):
+    db_session.add_all(
+        [
+            Notification(user_id=test_user.id, title="One", body="Body", type="system"),
+            Notification(user_id=test_user.id, title="Two", body="Body", type="system"),
+        ]
+    )
+    await db_session.commit()
+
+    response = await async_client.delete("/api/v1/notifications", headers=auth_headers)
+
+    assert response.status_code == 200
+    result = await db_session.execute(
+        select(Notification).where(Notification.user_id == test_user.id)
+    )
+    assert result.scalars().all() == []
diff --git a/backend-service/tests/test_podcasts_routes.py b/backend-service/tests/test_podcasts_routes.py
index 37a93125..d797fd29 100644
--- a/backend-service/tests/test_podcasts_routes.py
+++ b/backend-service/tests/test_podcasts_routes.py
@@ -578,38 +578,100 @@ async def test_cache_key_includes_feed_url(self, no_db_client: AsyncClient):
 # ============================================================================
 
 class TestTranscriptEndpoint:
-    """Tests for POST /podcasts/transcript placeholder endpoint."""
+    """Tests for POST /podcasts/transcript endpoint."""
 
     @pytest.mark.asyncio
-    async def test_returns_pending_status(self, no_db_client: AsyncClient):
-        response = await no_db_client.post(
-            f"{BASE}/transcript",
-            json={
-                "feed_url": "https://example.com/feed.rss",
-                "episode_guid": "ep001",
-                "audio_url": "https://example.com/ep1.mp3",
-            },
-        )
+    async def test_returns_ready_transcript_artifact(self, no_db_client: AsyncClient):
+        async def call_fetch(**kwargs):
+            data = await kwargs["fetch_fn"]()
+            mock_result = MagicMock()
+            mock_result.data = data
+            return mock_result
+
+        with patch("app.routes.podcasts.APICacheService") as MockCache, patch(
+            "app.routes.podcasts._fetch_rss_episodes",
+            new_callable=AsyncMock,
+        ) as mock_fetch:
+            mock_cache = AsyncMock()
+            mock_cache.get_or_fetch.side_effect = call_fetch
+            MockCache.return_value = mock_cache
+            mock_fetch.return_value = {
+                "episodes": [
+                    {
+                        "guid": "ep001",
+                        "title": "How to ask better questions",
+                        "description": "A short lesson about polite questions and follow-up phrases.",
+                        "audio_url": "https://example.com/ep1.mp3",
+                        "duration_seconds": 360,
+                    }
+                ]
+            }
+
+            response = await no_db_client.post(
+                f"{BASE}/transcript",
+                json={
+                    "feed_url": "https://example.com/feed.rss",
+                    "episode_guid": "ep001",
+                    "audio_url": "https://example.com/ep1.mp3",
+                },
+            )
+
         assert response.status_code == 200
         data = response.json()
-        assert data["status"] == "pending"
-        assert "message" in data
+        assert data["status"] == "ready"
+        assert data["source"] == "rss_summary"
+        assert data["requires_stt"] is False
+        assert "polite questions" in data["transcript"]
+        assert len(data["segments"]) == 3
 
     @pytest.mark.asyncio
     async def test_echoes_back_feed_url_and_guid(self, no_db_client: AsyncClient):
-        response = await no_db_client.post(
-            f"{BASE}/transcript",
-            json={
-                "feed_url": "https://example.com/myfeed.rss",
-                "episode_guid": "guid-12345",
-                "audio_url": "https://example.com/audio.mp3",
-            },
-        )
+        mock_result = MagicMock()
+        mock_result.data = {
+            "message": "cached",
+            "status": "ready",
+            "feed_url": "https://example.com/myfeed.rss",
+            "episode_guid": "guid-12345",
+            "audio_url": "https://example.com/audio.mp3",
+            "transcript": "Cached transcript",
+            "segments": [],
+            "source": "rss_summary",
+            "requires_stt": False,
+        }
+
+        with patch("app.routes.podcasts.APICacheService") as MockCache:
+            mock_cache = AsyncMock()
+            mock_cache.get_or_fetch.return_value = mock_result
+            MockCache.return_value = mock_cache
+
+            response = await no_db_client.post(
+                f"{BASE}/transcript",
+                json={
+                    "feed_url": "https://example.com/myfeed.rss",
+                    "episode_guid": "guid-12345",
+                    "audio_url": "https://example.com/audio.mp3",
+                },
+            )
+
         assert response.status_code == 200
         data = response.json()
         assert data["feed_url"] == "https://example.com/myfeed.rss"
         assert data["episode_guid"] == "guid-12345"
 
+    def test_build_transcript_artifact_falls_back_to_request_metadata(self):
+        from app.routes.podcasts import _build_transcript_artifact
+
+        artifact = _build_transcript_artifact(
+            feed_url="https://example.com/feed.rss",
+            episode_guid="missing",
+            audio_url="https://example.com/audio.mp3",
+            episode=None,
+        )
+
+        assert artifact["status"] == "ready"
+        assert artifact["source"] == "request_metadata"
+        assert "Transcript audio is not available yet" in artifact["transcript"]
+
 
 # ============================================================================
 # Integration Tests — _fetch_podcast_search internal function
diff --git a/backend-service/tests/test_proficiency_api_integration.py b/backend-service/tests/test_proficiency_api_integration.py
index 702a5aec..e22a409d 100644
--- a/backend-service/tests/test_proficiency_api_integration.py
+++ b/backend-service/tests/test_proficiency_api_integration.py
@@ -13,35 +13,34 @@
   6. GET  /proficiency/placement-test     — returns 20 questions without answers
   7. POST /proficiency/placement-test/submit — correct scoring and level assignment
 
-Prerequisites:
-  - Run seed first:  python -m tests.seed_proficiency_data
-
 Usage:
   cd backend-service
   pytest tests/test_proficiency_api_integration.py -v
 """
 
-import pytest
+# ruff: noqa: E402
+
+import asyncio
 import sys
+from collections.abc import AsyncGenerator
 from pathlib import Path
-from typing import AsyncGenerator
 
-from httpx import AsyncClient, ASGITransport
+import pytest
+from httpx import ASGITransport, AsyncClient
 from sqlalchemy import select
-from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 from sqlalchemy.pool import NullPool
 
 BACKEND_ROOT = Path(__file__).resolve().parents[1]
 if str(BACKEND_ROOT) not in sys.path:
     sys.path.insert(0, str(BACKEND_ROOT))
 
-from app.main import app
+from app.core.config import settings as app_settings
 from app.core.database import get_db
 from app.core.dependencies import get_current_user
+from app.main import app
 from app.models.user import User
-from app.models.proficiency import SkillType
-
-from app.core.config import settings as app_settings
+from tests.seed_proficiency_data import seed as seed_proficiency_data
 
 DB_URL = app_settings.DATABASE_URL
 BASE = "/api/v1/proficiency"
@@ -59,19 +58,25 @@
 @pytest.fixture(autouse=True)
 def disable_rate_limiting(monkeypatch):
     from app.core.middleware import RateLimitMiddleware
+
     async def mock_dispatch(self, request, call_next):
         return await call_next(request)
+
     monkeypatch.setattr(RateLimitMiddleware, "dispatch", mock_dispatch)
 
 
+@pytest.fixture(scope="module", autouse=True)
+def seed_database() -> None:
+    """Reset deterministic proficiency data before this module mutates it."""
+    asyncio.run(seed_proficiency_data())
+
+
 @pytest.fixture
 async def auth_client() -> AsyncGenerator[AsyncClient, None]:
     """
     Authenticated HTTP client.
-    
-    Prerequisite: run `python -m tests.seed_proficiency_data` before tests.
-    The seed script populates the DB with proficiency data for the target user.
     """
+
     async def override_get_db():
         async with _session_factory() as session:
             yield session
@@ -82,8 +87,7 @@ async def override_get_user():
             user = result.scalar_one_or_none()
             if user is None:
                 pytest.fail(
-                    f"User '{TARGET_EMAIL}' not found. "
-                    "Run: python -m tests.seed_proficiency_data"
+                    f"User '{TARGET_EMAIL}' not found. Run: python -m tests.seed_proficiency_data"
                 )
             return user
 
@@ -109,6 +113,7 @@ async def no_auth_client() -> AsyncGenerator[AsyncClient, None]:
 # 1. GET /proficiency/profile
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestGetProfile:
     """Test proficiency profile retrieval with seeded data."""
 
@@ -177,6 +182,7 @@ async def test_unauthorized_returns_401(self, no_auth_client):
 # 2. POST /proficiency/record-exercises
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestRecordExercises:
     """Test recording new exercises on top of seeded data."""
 
@@ -263,26 +269,30 @@ async def test_empty_exercises_returns_error(self, auth_client):
         assert resp.status_code in (200, 422)
 
     async def test_invalid_skill_returns_422(self, auth_client):
-        exercises = [{
-            "exercise_type": "test",
-            "skill": "nonexistent_skill",
-            "difficulty_level": "A1",
-            "is_correct": True,
-            "score": 50.0,
-            "time_spent_seconds": 10,
-        }]
+        exercises = [
+            {
+                "exercise_type": "test",
+                "skill": "nonexistent_skill",
+                "difficulty_level": "A1",
+                "is_correct": True,
+                "score": 50.0,
+                "time_spent_seconds": 10,
+            }
+        ]
         resp = await auth_client.post(f"{BASE}/record-exercises", json=exercises)
         assert resp.status_code == 422
 
     async def test_invalid_score_range_returns_422(self, auth_client):
-        exercises = [{
-            "exercise_type": "test",
-            "skill": "vocabulary",
-            "difficulty_level": "A1",
-            "is_correct": True,
-            "score": 150.0,  # out of range
-            "time_spent_seconds": 10,
-        }]
+        exercises = [
+            {
+                "exercise_type": "test",
+                "skill": "vocabulary",
+                "difficulty_level": "A1",
+                "is_correct": True,
+                "score": 150.0,  # out of range
+                "time_spent_seconds": 10,
+            }
+        ]
         resp = await auth_client.post(f"{BASE}/record-exercises", json=exercises)
         assert resp.status_code == 422
 
@@ -295,6 +305,7 @@ async def test_unauthorized_returns_401(self, no_auth_client, sample_exercises):
 # 3. GET /proficiency/level-check
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestLevelCheck:
     """Test level-check endpoint with seeded B1 user."""
 
@@ -347,6 +358,7 @@ async def test_unauthorized_returns_401(self, no_auth_client):
 # 4. GET /proficiency/level-thresholds
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestLevelThresholds:
     """Test level thresholds endpoint (no auth required)."""
 
@@ -393,6 +405,7 @@ async def test_c2_has_all_skill_requirements(self, no_auth_client):
 # 5. GET /proficiency/history
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestHistory:
     """Test level history with seeded transitions."""
 
@@ -439,6 +452,7 @@ async def test_unauthorized_returns_401(self, no_auth_client):
 # 6. GET /proficiency/placement-test
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestPlacementTest:
     """Test placement test question retrieval."""
 
@@ -479,6 +493,7 @@ async def test_unauthorized_returns_401(self, no_auth_client):
 # 7. POST /proficiency/placement-test/submit
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestPlacementSubmit:
     """Test placement test submission and scoring."""
 
@@ -569,6 +584,7 @@ async def test_unauthorized_returns_401(self, no_auth_client):
 # 8. Cross-endpoint Consistency Tests
 # ═══════════════════════════════════════════════════════════════════════
 
+
 class TestCrossEndpointConsistency:
     """Verify data consistency across multiple endpoints."""
 
diff --git a/backend-service/tests/test_proficiency_functional.py b/backend-service/tests/test_proficiency_functional.py
index df59ea52..13e24a7b 100644
--- a/backend-service/tests/test_proficiency_functional.py
+++ b/backend-service/tests/test_proficiency_functional.py
@@ -23,6 +23,7 @@
 
 import pytest
 import sys
+from datetime import UTC, datetime, timedelta
 from pathlib import Path
 from typing import Dict
 
@@ -488,7 +489,54 @@ def test_level_index(self):
 
 
 # ═══════════════════════════════════════════════════════════════════════
-# 6. Level Thresholds Configuration
+# 6. Assessment Suggestion Logic
+# ═══════════════════════════════════════════════════════════════════════
+
+class TestAssessmentSuggestion:
+    """Test formal assessment suggestion rules."""
+
+    def _profile(
+        self,
+        *,
+        last_full_assessment: datetime | None,
+        assessment_count: int = 50,
+        score: float = 70,
+    ) -> ProficiencyProfile:
+        return ProficiencyProfile(
+            user_id="user-1",
+            overall_level=ProficiencyLevel.A1,
+            skills={
+                skill: SkillAssessment(
+                    skill=skill,
+                    score=score,
+                    level=ProficiencyLevel.A1,
+                    confidence=1.0,
+                    total_exercises=assessment_count,
+                    correct_exercises=int(assessment_count * 0.8),
+                )
+                for skill in SkillType
+            },
+            assessment_count=assessment_count,
+            last_full_assessment=last_full_assessment,
+        )
+
+    def test_accepts_timezone_aware_last_assessment(self):
+        profile = self._profile(
+            last_full_assessment=datetime.now(UTC) - timedelta(days=8),
+        )
+
+        assert ProficiencyService.should_suggest_assessment(profile) is True
+
+    def test_recent_timezone_aware_assessment_suppresses_suggestion(self):
+        profile = self._profile(
+            last_full_assessment=datetime.now(UTC) - timedelta(days=2),
+        )
+
+        assert ProficiencyService.should_suggest_assessment(profile) is False
+
+
+# ═══════════════════════════════════════════════════════════════════════
+# 7. Level Thresholds Configuration
 # ═══════════════════════════════════════════════════════════════════════
 
 class TestLevelThresholds:
diff --git a/backend-service/tests/test_quota_manager.py b/backend-service/tests/test_quota_manager.py
new file mode 100644
index 00000000..2599351b
--- /dev/null
+++ b/backend-service/tests/test_quota_manager.py
@@ -0,0 +1,89 @@
+from datetime import date
+
+import pytest
+
+from app.services import quota_manager
+from app.services.quota_manager import QuotaManager, QuotaStatus
+
+
+def test_quota_key_uses_utc_date(monkeypatch):
+    monkeypatch.setattr(
+        quota_manager,
+        "_utc_today",
+        lambda: date(2026, 6, 26),
+    )
+
+    assert QuotaManager._redis_key("newsapi") == "quota:newsapi:2026-06-26"
+
+
+def test_reset_time_returns_human_readable_duration():
+    reset_time = QuotaManager.get_reset_time()
+
+    assert "h" in reset_time
+    assert "m" in reset_time
+
+
+@pytest.mark.asyncio
+async def test_unknown_api_usage_is_not_recorded(monkeypatch):
+    class FakeRedis:
+        def __init__(self):
+            self.incrby_calls = []
+
+        async def incrby(self, key, cost):
+            self.incrby_calls.append((key, cost))
+            return cost
+
+        async def expire(self, key, ttl):
+            return True
+
+    redis = FakeRedis()
+
+    async def fake_get_instance():
+        return redis
+
+    monkeypatch.setattr(
+        quota_manager.RedisClient,
+        "get_instance",
+        fake_get_instance,
+    )
+
+    status = await QuotaManager.record_request("unknown-api")
+
+    assert status == QuotaStatus.NORMAL
+    assert redis.incrby_calls == []
+
+
+@pytest.mark.asyncio
+async def test_zero_cost_usage_is_not_recorded(monkeypatch):
+    class FakeRedis:
+        def __init__(self):
+            self.incrby_calls = []
+
+        async def get(self, key):
+            return 0
+
+        async def incrby(self, key, cost):
+            self.incrby_calls.append((key, cost))
+            return cost
+
+    redis = FakeRedis()
+
+    async def fake_get_instance():
+        return redis
+
+    monkeypatch.setattr(
+        quota_manager.RedisClient,
+        "get_instance",
+        fake_get_instance,
+    )
+
+    status = await QuotaManager.record_request("youtube", cost=0)
+
+    assert status == QuotaStatus.NORMAL
+    assert redis.incrby_calls == []
+
+
+@pytest.mark.asyncio
+async def test_negative_quota_cost_is_rejected():
+    with pytest.raises(ValueError, match="non-negative"):
+        await QuotaManager.record_request("youtube", cost=-1)
diff --git a/backend-service/tests/test_schema_pydantic_v2_debt.py b/backend-service/tests/test_schema_pydantic_v2_debt.py
new file mode 100644
index 00000000..0bb094ee
--- /dev/null
+++ b/backend-service/tests/test_schema_pydantic_v2_debt.py
@@ -0,0 +1,28 @@
+import re
+from pathlib import Path
+
+
+SCHEMA_DIR = Path(__file__).resolve().parents[1] / "app" / "schemas"
+
+
+def test_schemas_do_not_use_pydantic_v1_config_or_validators():
+    offenders: dict[str, list[str]] = {}
+
+    for path in sorted(SCHEMA_DIR.glob("*.py")):
+        source = path.read_text(encoding="utf-8")
+        issues: list[str] = []
+
+        if "class Config:" in source:
+            issues.append("class Config")
+        if re.search(r"from pydantic import .*\bvalidator\b", source):
+            issues.append("validator import")
+        if re.search(r"@validator\(", source):
+            issues.append("@validator")
+
+        if issues:
+            offenders[path.name] = issues
+
+    assert not offenders, (
+        "Use Pydantic v2 APIs in schemas: ConfigDict/model_config and "
+        f"field_validator/model_validator. Offenders: {offenders}"
+    )
diff --git a/backend-service/tests/test_shop_catalog.py b/backend-service/tests/test_shop_catalog.py
index bf41b9b9..853ef036 100644
--- a/backend-service/tests/test_shop_catalog.py
+++ b/backend-service/tests/test_shop_catalog.py
@@ -1,10 +1,15 @@
-from app.core.shop_catalog import AVATAR_SHOP_ITEMS, CONSUMABLE_SHOP_ITEMS, SHOP_CATALOG
+from app.core.shop_catalog import (
+    AVATAR_SHOP_ITEMS,
+    CONSUMABLE_SHOP_ITEMS,
+    GAME_POWERUP_ITEM_TYPES,
+    SHOP_CATALOG,
+)
 
 
 def test_catalog_contains_affordable_consumables_and_many_avatars():
-    assert len(CONSUMABLE_SHOP_ITEMS) == 9
+    assert len(CONSUMABLE_SHOP_ITEMS) == 19
     assert len(AVATAR_SHOP_ITEMS) == 36
-    assert len(SHOP_CATALOG) == 45
+    assert len(SHOP_CATALOG) == 55
 
     prices = {item["name"]: item["price_gems"] for item in CONSUMABLE_SHOP_ITEMS}
     assert prices["Hint Pack (5)"] == 12
@@ -13,6 +18,20 @@ def test_catalog_contains_affordable_consumables_and_many_avatars():
     assert prices["Streak Freeze"] == 25
 
 
+def test_catalog_contains_all_game_powerup_items():
+    powerup_items = {
+        item["item_type"]: item
+        for item in CONSUMABLE_SHOP_ITEMS
+        if item["item_type"] in GAME_POWERUP_ITEM_TYPES
+    }
+    assert set(powerup_items) == set(GAME_POWERUP_ITEM_TYPES)
+    assert powerup_items["time_freeze"]["effects"] == {"seconds": 10}
+    assert powerup_items["extra_time"]["effects"] == {"seconds": 20}
+    assert powerup_items["lucky_clover"]["effects"] == {"chance": 0.3}
+    assert powerup_items["score_multiplier"]["effects"] == {"multiplier": 2}
+    assert all(item["price_gems"] > 0 for item in powerup_items.values())
+
+
 def test_avatar_catalog_uses_adventurer_urls_and_low_price_tiers():
     assert {item["price_gems"] for item in AVATAR_SHOP_ITEMS} == {10, 15, 20}
     assert all(item["item_type"] == "avatar" for item in AVATAR_SHOP_ITEMS)
diff --git a/backend-service/tests/test_streak_service.py b/backend-service/tests/test_streak_service.py
new file mode 100644
index 00000000..d64a0f86
--- /dev/null
+++ b/backend-service/tests/test_streak_service.py
@@ -0,0 +1,42 @@
+from datetime import date
+from unittest.mock import AsyncMock, MagicMock
+from uuid import uuid4
+
+import pytest
+
+from app.services import streak_service
+from app.services.streak_service import update_user_streak
+
+
+def _result(value=None):
+    result = MagicMock()
+    result.scalar_one_or_none.return_value = value
+    return result
+
+
+@pytest.mark.asyncio
+async def test_update_user_streak_uses_utc_service_date(monkeypatch):
+    fixed_today = date(2026, 6, 26)
+    monkeypatch.setattr(streak_service, "_utc_today", lambda: fixed_today)
+    monkeypatch.setattr(
+        streak_service,
+        "check_achievements_for_user",
+        AsyncMock(return_value=[]),
+    )
+    monkeypatch.setattr(streak_service, "delete_cached", AsyncMock())
+
+    db = MagicMock()
+    db.execute = AsyncMock(side_effect=[_result(None), _result(None)])
+    db.add = MagicMock()
+    db.flush = AsyncMock()
+
+    streak, increased, saved, achievements = await update_user_streak(
+        db,
+        uuid4(),
+    )
+
+    assert streak.last_activity_date == fixed_today
+    assert streak.current_streak == 1
+    assert increased is True
+    assert saved is False
+    assert achievements == []
diff --git a/backend-service/tests/test_users_routes.py b/backend-service/tests/test_users_routes.py
index f7f809c4..1b1b29d3 100644
--- a/backend-service/tests/test_users_routes.py
+++ b/backend-service/tests/test_users_routes.py
@@ -16,7 +16,7 @@
 
 import pytest
 import uuid
-from datetime import datetime
+from datetime import UTC, datetime
 from unittest.mock import AsyncMock, MagicMock, patch
 from httpx import AsyncClient, ASGITransport
 
@@ -46,8 +46,8 @@ def _make_mock_user(user_id: str = "550e8400-e29b-41d4-a716-446655440001"):
     user.rank = "bronze"
     user.avatar_url = None
     user.bio = None
-    user.created_at = datetime.utcnow()
-    user.updated_at = datetime.utcnow()
+    user.created_at = datetime.now(UTC)
+    user.updated_at = datetime.now(UTC)
     user.last_login = None
     user.role_slug = "user"
     user.role_id = None
diff --git a/backend-service/tests/test_vocabulary_routes.py b/backend-service/tests/test_vocabulary_routes.py
index 48322d7a..2f1626ba 100644
--- a/backend-service/tests/test_vocabulary_routes.py
+++ b/backend-service/tests/test_vocabulary_routes.py
@@ -18,7 +18,7 @@
 
 import pytest
 import uuid
-from datetime import datetime, date, timedelta
+from datetime import UTC, datetime, date, timedelta
 from typing import List
 from unittest.mock import AsyncMock, MagicMock, patch
 from httpx import AsyncClient, ASGITransport
@@ -124,8 +124,8 @@ def _make_mock_vocab_item(vocab_id: str = VOCAB_ID):
     item.course_id = None
     item.lesson_id = None
     item.usage_frequency = 0
-    item.created_at = datetime.utcnow()
-    item.updated_at = datetime.utcnow()
+    item.created_at = datetime.now(UTC)
+    item.updated_at = datetime.now(UTC)
     return item
 
 
@@ -140,7 +140,7 @@ def _make_mock_user_vocab():
     uv.interval = 1
     uv.streak = 0
     uv.repetitions = 0
-    uv.next_review_date = datetime.utcnow()
+    uv.next_review_date = datetime.now(UTC)
     uv.last_reviewed_at = None
     uv.fsrs_stability = 0.0
     uv.fsrs_difficulty = 0.0
@@ -157,7 +157,7 @@ def _make_mock_user_vocab():
     uv.longest_streak = 0
     uv.total_xp_earned = 0
     uv.notes = None
-    uv.added_at = datetime.utcnow()
+    uv.added_at = datetime.now(UTC)
     return uv
 
 
@@ -270,6 +270,15 @@ async def test_response_has_items_and_total(self, auth_client):
         assert "items" in data
         assert "total" in data
 
+    @pytest.mark.asyncio
+    async def test_total_comes_from_count_query(self, auth_client):
+        client, _, _, _ = auth_client
+        with patch("app.crud.vocabulary.vocabulary_crud.get_user_vocabulary_list", new=AsyncMock(return_value=[])), \
+             patch("app.crud.vocabulary.vocabulary_crud.count_user_vocabulary", new=AsyncMock(return_value=42)):
+            response = await client.get(f"{BASE}/collection")
+        assert response.status_code == 200
+        assert response.json()["total"] == 42
+
     @pytest.mark.asyncio
     async def test_invalid_status_returns_400(self, auth_client):
         client, _, _, _ = auth_client
@@ -727,7 +736,7 @@ async def test_creates_deck_successfully(self, auth_client):
         mock_deck.name = "Travel Phrases"
         mock_deck.description = "Words for travel"
         mock_deck.color = "#2196F3"
-        mock_deck.created_at = datetime.utcnow()
+        mock_deck.created_at = datetime.now(UTC)
         mock_deck.user_id = "00000000-0000-0000-0000-000000000001"
         mock_deck.word_count = 0
         with patch("app.crud.vocabulary.vocabulary_crud.create_deck", new=AsyncMock(return_value=mock_deck)):
@@ -774,7 +783,7 @@ async def test_returns_user_decks(self, auth_client):
         mock_deck.name = "Travel Phrases"
         mock_deck.description = "Words for travel"
         mock_deck.color = "#2196F3"
-        mock_deck.created_at = datetime.utcnow()
+        mock_deck.created_at = datetime.now(UTC)
         mock_deck.user_id = "00000000-0000-0000-0000-000000000001"
         mock_deck.word_count = 5
         with patch("app.crud.vocabulary.vocabulary_crud.get_user_decks", new=AsyncMock(return_value=[mock_deck])):
diff --git a/backend-service/tests/test_well_known_routes.py b/backend-service/tests/test_well_known_routes.py
new file mode 100644
index 00000000..e690567a
--- /dev/null
+++ b/backend-service/tests/test_well_known_routes.py
@@ -0,0 +1,19 @@
+"""Route coverage for app/universal link metadata."""
+
+import pytest
+from httpx import ASGITransport, AsyncClient
+
+from app.main import app
+
+
+@pytest.mark.asyncio
+async def test_well_known_routes_are_mounted():
+    transport = ASGITransport(app=app)
+    async with AsyncClient(transport=transport, base_url="http://test") as client:
+        assetlinks = await client.get("/.well-known/assetlinks.json")
+        aasa = await client.get("/.well-known/apple-app-site-association")
+
+    assert assetlinks.status_code == 200
+    assert assetlinks.json()[0]["target"]["namespace"] == "android_app"
+    assert aasa.status_code == 200
+    assert "applinks" in aasa.json()
diff --git a/backend-service/tests/test_xp_service.py b/backend-service/tests/test_xp_service.py
index a5dca613..e05cad1b 100644
--- a/backend-service/tests/test_xp_service.py
+++ b/backend-service/tests/test_xp_service.py
@@ -135,6 +135,80 @@ async def test_award_creates_current_week_leaderboard_entry():
     assert leaderboard_entries[0].league == user.rank
 
 
+# ── Game XP must respect a purchased double_xp/triple_xp shop boost ──────────
+
+@pytest.mark.asyncio
+async def test_game_xp_award_applies_item_multiplier_on_top_of_streak():
+    """A purchased Double XP boost (item_multiplier=2.0) must scale game XP,
+    not just lesson/challenge XP — this was previously a dead purchase for
+    players who only play the mini-games."""
+    user_id = uuid.uuid4()
+    user = _make_user(user_id)
+    daily = SimpleNamespace(xp_earned=0)
+    leaderboard = SimpleNamespace(xp_earned=0, league="bronze")
+    db = MagicMock()
+    db.execute = AsyncMock(
+        side_effect=[
+            _result(scalar_one_or_none=user),
+            _result(scalar_one_or_none=None),
+            MagicMock(),
+            _result(scalar_one_or_none=daily),
+            _result(scalar_one_or_none=leaderboard),
+        ]
+    )
+    db.add = MagicMock()
+    db.commit = AsyncMock()
+
+    result = await award_xp_transaction(
+        db=db,
+        user=user,
+        source="game",
+        base_xp=10,
+        source_id="game-session-001",
+        item_multiplier=2.0,
+        daily_xp_loader=AsyncMock(return_value=0),
+        streak_loader=AsyncMock(return_value=0),
+    )
+
+    assert result.multiplier == 2.0
+    assert result.xp_awarded == 20
+
+
+@pytest.mark.asyncio
+async def test_item_multiplier_below_one_does_not_reduce_xp():
+    """A missing/invalid boost (item_multiplier < 1.0) must never penalize XP."""
+    user_id = uuid.uuid4()
+    user = _make_user(user_id)
+    daily = SimpleNamespace(xp_earned=0)
+    leaderboard = SimpleNamespace(xp_earned=0, league="bronze")
+    db = MagicMock()
+    db.execute = AsyncMock(
+        side_effect=[
+            _result(scalar_one_or_none=user),
+            _result(scalar_one_or_none=None),
+            MagicMock(),
+            _result(scalar_one_or_none=daily),
+            _result(scalar_one_or_none=leaderboard),
+        ]
+    )
+    db.add = MagicMock()
+    db.commit = AsyncMock()
+
+    result = await award_xp_transaction(
+        db=db,
+        user=user,
+        source="game",
+        base_xp=10,
+        source_id="game-session-002",
+        item_multiplier=0.0,
+        daily_xp_loader=AsyncMock(return_value=0),
+        streak_loader=AsyncMock(return_value=0),
+    )
+
+    assert result.multiplier == 1.0
+    assert result.xp_awarded == 10
+
+
 # ── Task 5: source_id requirement for repeat-sensitive sources ────────────────
 
 @pytest.mark.parametrize("source", sorted(REPEAT_SENSITIVE_SOURCES))
diff --git a/backend-service/tests/test_youtube_routes.py b/backend-service/tests/test_youtube_routes.py
index 2b8f5d76..a53c61b3 100644
--- a/backend-service/tests/test_youtube_routes.py
+++ b/backend-service/tests/test_youtube_routes.py
@@ -28,8 +28,12 @@ async def no_db_client():
     from app.main import app
     from app.core.database import get_db
 
+    class NoDbSession:
+        async def execute(self, *args, **kwargs):
+            raise RuntimeError("Database is disabled for this route test")
+
     async def mock_get_db():
-        yield AsyncMock()
+        yield NoDbSession()
 
     app.dependency_overrides[get_db] = mock_get_db
     transport = ASGITransport(app=app)
@@ -310,6 +314,7 @@ async def test_search_with_channel_id_filter(self, no_db_client: AsyncClient):
         call_args = mock_cache_instance.get_or_fetch.call_args
         cache_key = call_args.kwargs.get("cache_key") or call_args.args[0]
         assert "UCHaHD477h-FeBbVh9Sh7syA" in cache_key
+        assert call_args.kwargs["cost"] == 100
 
 
 # ============================================================================
@@ -402,6 +407,7 @@ async def test_permanent_cache_key_includes_video_and_lang(self, no_db_client: A
 
         call_kwargs = mock_cache_instance.get_or_fetch.call_args.kwargs
         assert call_kwargs["cache_key"] == "youtube:captions:myVideoId123:en"
+        assert call_kwargs["cost"] == 0
 
 
 # ============================================================================
@@ -459,6 +465,7 @@ async def test_returns_videos_for_channel(self, no_db_client: AsyncClient):
         assert data["channel_id"] == "UCHaHD477h-FeBbVh9Sh7syA"
         assert "data" in data
         assert "source" in data
+        assert mock_cache_instance.get_or_fetch.call_args.kwargs["cost"] == 100
 
     @pytest.mark.asyncio
     async def test_max_results_validation(self, no_db_client: AsyncClient):
@@ -745,6 +752,7 @@ async def test_translate_returns_word_data(self, no_db_client):
     async def test_translate_passes_context_to_fetch(self, no_db_client):
         """context query param is forwarded to the cache fetch_fn."""
         captured_context: list[str] = []
+        captured_cost: list[int] = []
 
         mock_result = MagicMock()
         mock_result.data = {
@@ -756,6 +764,7 @@ async def capture_fetch(cache_key, api_name, fetch_fn, **kwargs):
             # Execute fetch_fn to capture the context via _fetch_word_data signature
             # We just verify cache_key is stable (word+lang, not context)
             captured_context.append(cache_key)
+            captured_cost.append(kwargs["cost"])
             return mock_result
 
         with patch("app.routes.youtube.APICacheService") as MockCache:
@@ -770,6 +779,7 @@ async def capture_fetch(cache_key, api_name, fetch_fn, **kwargs):
         assert resp.status_code == 200
         # Cache key must NOT include context (stable hit rate)
         assert captured_context[0] == "youtube:translate:run:vi"
+        assert captured_cost[0] == 0
 
     @pytest.mark.asyncio
     async def test_translate_returns_empty_on_exception(self, no_db_client):
diff --git a/docs/superpowers/plans/2026-07-03-lexilingo-system-development.md b/docs/superpowers/plans/2026-07-03-lexilingo-system-development.md
new file mode 100644
index 00000000..cd224d5e
--- /dev/null
+++ b/docs/superpowers/plans/2026-07-03-lexilingo-system-development.md
@@ -0,0 +1,483 @@
+# LexiLingo System Development Implementation Plan
+
+> **For agentic workers:** REQUIRED: Use superpowers:subagent-driven-development (if subagents available) or superpowers:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Convert the current system audit into a sequence of small, testable improvements that make LexiLingo's learning loop more personalized, production-ready, and measurable.
+
+**Architecture:** Work incrementally across the existing FastAPI backend, AI service, Flutter app, and admin dashboard. Start with low-risk feature gaps that already have routes or UI surfaces, then move toward cross-service features such as synced mistakes, unified pronunciation, planner, premium enforcement, and analytics.
+
+**Tech Stack:** FastAPI, SQLAlchemy async, Alembic, pytest, Flutter Provider/Repository pattern, SharedPreferences, RevenueCat, React admin, GitHub Actions.
+
+---
+
+## Scope And Evidence
+
+This plan is based on a read-only system audit. `code-review-graph` reported 1327 files, 12800 nodes, and 96934 edges; architecture community output was empty and hotspot tools failed with an internal path-resolution error, so direct source inspection is used for feature-level evidence.
+
+Key gaps to close:
+
+- News quiz generation is still placeholder logic in `backend-service/app/routes/news.py`.
+- Mistake notebook entries are local-only in `flutter-app/lib/features/mistakes/data/mistake_notebook_repository.dart`.
+- General voice practice still scores pronunciation from transcript similarity in `flutter-app/lib/features/voice/data/repositories/voice_repository_impl.dart` instead of the HuBERT pronunciation pipeline.
+- Today plan is client-side heuristic logic in `flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_models.dart`.
+- CEFR proficiency recording exists but is not consistently wired into all learning completion flows.
+- Premium gating is client-side and lacks backend entitlement enforcement.
+- Several analytics, achievement, and CI surfaces remain placeholder or partial.
+
+## File Map
+
+### Phase 1: Content Learning Quality
+
+- Modify: `backend-service/app/routes/news.py`
+  - Replace placeholder news quiz with deterministic article-aware quiz generation and optional article context.
+- Modify: `backend-service/tests/test_news_routes.py`
+  - Add unit tests that prevent placeholder options/explanations from returning.
+  - Add tests for article-aware vocabulary and comprehension generation.
+
+### Phase 2: Synced Mistake Notebook
+
+- Create: `backend-service/app/models/mistake.py`
+  - Store user mistake notebook entries with source metadata, prompt, expected answer, selected answer, skill, status, and timestamps.
+- Create: `backend-service/app/schemas/mistakes.py`
+  - Request/response schemas for create, list, resolve, and delete.
+- Create: `backend-service/app/routes/mistakes.py`
+  - Authenticated `/mistakes` API for user-owned entries.
+- Modify: `backend-service/app/main.py`
+  - Include the new mistakes router.
+- Modify: `backend-service/app/models/__init__.py`
+  - Export the new model for metadata registration.
+- Create: `backend-service/alembic/versions/add_mistake_notebook_entries.py`
+  - Add `mistake_notebook_entries` table and indexes.
+- Create: `backend-service/tests/test_mistakes_routes.py`
+  - Cover create/list/resolve/delete and user isolation.
+- Modify: `flutter-app/lib/features/mistakes/data/mistake_notebook_repository.dart`
+  - Add sync-aware repository behavior while preserving offline fallback.
+- Create: `flutter-app/lib/features/mistakes/data/mistake_notebook_remote_datasource.dart`
+  - Call backend API.
+- Modify: game, news, and books providers that currently record mistakes locally.
+
+### Phase 3: Unified Pronunciation Coach
+
+- Modify: `flutter-app/lib/features/voice/data/datasources/voice_remote_datasource.dart`
+  - Add a backend pronunciation-evaluation call that sends audio and target text.
+- Modify: `flutter-app/lib/features/voice/data/repositories/voice_repository_impl.dart`
+  - Prefer server HuBERT/phoneme scoring; keep transcript heuristic only as fallback.
+- Modify: `flutter-app/lib/features/voice/domain/entities/pronunciation_score.dart`
+  - Add phoneme/stress/error metadata if missing.
+- Test: `flutter-app/test/features/voice/...`
+  - Cover success response, fallback response, and error messaging.
+
+### Phase 4: Server-Side Today Plan
+
+- Create: `backend-service/app/schemas/today_plan.py`
+  - Define plan item, priority, reason, destination, completion state.
+- Create: `backend-service/app/services/today_plan_service.py`
+  - Build plan from due vocabulary, mistakes, proficiency, streak, and available content.
+- Create: `backend-service/app/routes/today_plan.py`
+  - Authenticated `/today-plan` endpoint.
+- Modify: `backend-service/app/main.py`
+  - Include router.
+- Modify: `flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_models.dart`
+  - Use backend plan when available; fallback to local heuristic.
+- Test: backend unit tests and Flutter provider/widget tests.
+
+### Phase 5: CEFR And Learning Event Integration
+
+- Modify: `backend-service/app/routes/learning.py`
+  - Emit normalized exercise result payloads after answer submission.
+- Modify: `backend-service/app/services/proficiency_service.py`
+  - Accept learning events from course, game, voice, and content activities.
+- Modify: `flutter-app/lib/features/level/presentation/providers/proficiency_provider.dart`
+  - Trigger `recordExercises` after lesson/game/content completion where missing.
+- Test: backend proficiency tests and Flutter flow tests.
+
+### Phase 6: Premium Entitlements
+
+- Create: `backend-service/app/models/entitlement.py`
+  - Store subscription state, provider, product ID, expiration, and last validation timestamp.
+- Create: `backend-service/app/routes/entitlements.py`
+  - Sync RevenueCat entitlement state and expose current user entitlement.
+- Create: `backend-service/app/services/entitlement_service.py`
+  - Validate and normalize provider payloads.
+- Modify: AI-heavy routes such as chat/pronunciation/TTS/content generation.
+  - Enforce free-tier limits and premium access server-side.
+- Modify: `flutter-app/lib/core/services/purchases_service.dart`
+  - Sync successful purchase/restore state to backend.
+- Test: backend route tests, entitlement service tests, and Flutter service tests.
+
+### Phase 7: Analytics, Achievements, And Admin Visibility
+
+- Modify: `backend-service/app/services/achievement_checker_service.py`
+  - Replace placeholder stats for voice, writing, listening, and time spent.
+- Modify: `backend-service/app/routes/analytics.py`
+  - Replace retention sample data with real event aggregation.
+- Modify: `admin-service/src/...`
+  - Surface mistake trends, CEFR movement, content quality, and conversion metrics.
+- Test: backend analytics tests and admin component tests.
+
+### Phase 8: CI And Production Hardening
+
+- Modify: `.github/workflows/ci.yml`
+  - Run a broader AI service pytest subset or full AI test suite behind cache/time budget.
+- Verify: `backend-service/.gitignore`, root `.gitignore`, and Gitleaks config.
+  - Keep service-account JSON, `.env`, generated data, coverage, and local DB artifacts out of git.
+- Test: run CI-equivalent commands locally where feasible.
+
+---
+
+## Chunk 1: Replace News Quiz Placeholder
+
+### Task 1: Article-Aware News Quiz Generator
+
+**Files:**
+
+- Modify: `backend-service/app/routes/news.py`
+- Modify: `backend-service/tests/test_news_routes.py`
+
+- [x] **Step 1: Add failing tests for non-placeholder quiz output**
+
+Add tests under `TestGenerateQuizStructure`:
+
+```python
+@pytest.mark.asyncio
+async def test_quiz_uses_article_context_when_available(self):
+    from app.routes.news import _generate_quiz
+
+    article = {
+        "title": "Solar Panels Power Local School",
+        "description": "Students learn from a new renewable energy project.",
+        "content": (
+            "A local school installed solar panels on the roof. "
+            "The project reduces electricity costs and teaches students about renewable energy. "
+            "Teachers said the panels will support science lessons throughout the year."
+        ),
+    }
+
+    quiz = await _generate_quiz("solar_school", article=article)
+
+    serialized = str(quiz).lower()
+    assert "solar" in serialized
+    assert "renewable" in serialized or "electricity" in serialized
+    assert "option a" not in serialized
+    assert "ai-generated" not in serialized
+```
+
+```python
+@pytest.mark.asyncio
+async def test_quiz_falls_back_to_article_id_without_placeholders(self):
+    from app.routes.news import _generate_quiz
+
+    quiz = await _generate_quiz("climate_policy_2026")
+
+    serialized = str(quiz).lower()
+    assert "option a" not in serialized
+    assert "ai-generated" not in serialized
+    assert quiz["total_questions"] == len(quiz["questions"])
+```
+
+- [x] **Step 2: Run the focused failing tests**
+
+Run:
+
+```bash
+cd backend-service
+./venv/bin/python -m pytest tests/test_news_routes.py::TestGenerateQuizStructure -q
+```
+
+Expected before implementation: new tests fail because `_generate_quiz` does not accept `article=` and returns placeholder text.
+
+Actual: failed for the expected reasons before implementation.
+
+- [x] **Step 3: Implement deterministic quiz generation**
+
+Implementation rules:
+
+- Keep `_generate_quiz(article_id: str)` backward compatible by adding `article: dict | None = None`.
+- Extract article text from `title`, `description`, and `content`.
+- Use simple sentence extraction for detail/comprehension questions.
+- Use `_extract_highlight_words(article)` for vocabulary questions.
+- Generate grammar question from an article sentence when possible.
+- Never return placeholder options such as `Option A` or explanations containing `AI-generated`.
+- Return exactly 5 questions, 4 options each, valid `correct_index`, `total_questions`, `xp_reward`.
+
+- [x] **Step 4: Wire route context without extra API cost**
+
+For `GET /news/{article_id}/quiz`, keep existing cache key. Do not add network fetches in this task. This task may only use the article payload if a future caller passes it internally; the route can continue calling `_generate_quiz(article_id)`.
+
+- [x] **Step 5: Run focused news tests**
+
+Run:
+
+```bash
+cd backend-service
+./venv/bin/python -m pytest tests/test_news_routes.py -q
+```
+
+Expected: all news route tests pass.
+
+Actual: `48 passed in 0.35s`.
+
+- [x] **Step 6: Update checklist**
+
+Mark completed steps in this plan after tests pass.
+
+---
+
+## Chunk 2: Synced Mistake Notebook API
+
+### Task 2: Backend Mistake Notebook Foundation
+
+**Files:**
+
+- Create: `backend-service/app/models/mistake.py`
+- Create: `backend-service/app/schemas/mistakes.py`
+- Create: `backend-service/app/routes/mistakes.py`
+- Create: `backend-service/alembic/versions/add_mistake_notebook_entries.py`
+- Create: `backend-service/tests/test_mistakes_routes.py`
+- Modify: `backend-service/app/main.py`
+- Modify: `backend-service/app/models/__init__.py`
+
+- [x] **Step 1: Write model and schema tests first**
+- [x] **Step 2: Create SQLAlchemy model**
+- [x] **Step 3: Create Alembic migration**
+- [x] **Step 4: Create authenticated CRUD routes**
+- [x] **Step 5: Include router in `main.py`**
+- [x] **Step 6: Run `./venv/bin/python -m pytest tests/test_mistakes_routes.py -q`**
+- [x] **Step 7: Run focused backend smoke tests for news quiz and mistake API behavior**
+
+Actual verification:
+
+```bash
+cd backend-service
+./venv/bin/python -m pytest tests/test_mistakes_routes.py -q
+# 4 passed in 29.45s
+
+./venv/bin/python -m pytest tests/test_news_routes.py tests/test_mistakes_routes.py -q
+# 55 passed in 71.84s
+
+./venv/bin/alembic heads
+# add_mistake_notebook_entries (head)
+```
+
+Reviewer-driven hardening:
+
+- Mistake duplicate matching now uses `source_type + source_id + question_hash`, not raw indexed question text or selected answer.
+- Client-provided review state, review counters, and timestamps are ignored by create/update; review state is server-owned through the review/reopen endpoints.
+- Client IDs are restricted to safe non-UUID strings.
+- Alembic smoke for the new migration passed by stamping the test DB at `add_game_powerup_items`, upgrading to `add_mistake_notebook_entries`, downgrading one revision, and upgrading again.
+
+Acceptance criteria:
+
+- Users can create, list, resolve, reopen, and delete only their own mistakes.
+- Duplicate source/question pairs can increment `attempt_count` instead of creating noisy duplicates.
+- API accepts current Flutter mistake fields without losing metadata.
+
+---
+
+## Chunk 3: Flutter Mistake Sync
+
+### Task 3: Offline-First Mistake Notebook Sync
+
+**Files:**
+
+- Create: `flutter-app/lib/features/mistakes/data/mistake_notebook_remote_datasource.dart`
+- Modify: `flutter-app/lib/features/mistakes/data/mistake_notebook_repository.dart`
+- Modify: `flutter-app/lib/features/mistakes/domain/mistake_notebook_entry.dart`
+- Modify: `flutter-app/lib/features/news/presentation/providers/news_provider.dart`
+- Modify: `flutter-app/lib/features/books/presentation/providers/book_provider.dart`
+- Modify: `flutter-app/lib/features/games/presentation/helpers/game_mistake_recorder.dart`
+- Test: `flutter-app/test/features/mistakes/...`
+
+- [x] **Step 1: Write repository tests for offline save, sync success, and sync failure**
+- [x] **Step 2: Add remote datasource using existing API/auth client conventions**
+- [x] **Step 3: Preserve SharedPreferences as local cache and retry queue**
+- [x] **Step 4: Trigger sync after local mistake saves**
+- [x] **Step 5: Run `flutter test test/features/mistakes/mistake_notebook_repository_test.dart`**
+- [x] **Step 6: Run `flutter analyze`**
+
+Implementation note:
+
+- Existing mistake producers did not need direct edits because `MistakeNotebookRepository` now uses the registered `ApiClient` from DI when available and falls back to local-only mode otherwise.
+- Remote failures queue upsert/review/delete operations in SharedPreferences and retry on the next load or mutation.
+- Local entries and pending sync operations are scoped by `UserScopeService` to avoid syncing one user's notebook into another account after logout/login.
+
+Actual verification:
+
+```bash
+cd flutter-app
+flutter test test/features/mistakes/mistake_notebook_repository_test.dart
+# All tests passed
+
+flutter test test/features/mistakes/mistake_notebook_repository_test.dart \
+  test/features/mistakes/mistake_notebook_remote_datasource_test.dart
+# All tests passed
+
+flutter test test/features/mistakes/mistake_notebook_repository_test.dart \
+  test/features/news/presentation/providers/news_provider_mistakes_test.dart \
+  test/features/games/presentation/helpers/game_mistake_recorder_test.dart
+# All tests passed
+
+flutter analyze
+# No issues found! (ran in 43.5s)
+```
+
+Reviewer-driven hardening:
+
+- Pending remote operations are scoped by active user and are not flushed under a different user scope.
+- Pending delete/review/upsert IDs suppress stale remote merge until the pending operation succeeds.
+- Remote datasource paginates `/mistakes` with `limit=100` and `offset`.
+- Path IDs are URL-encoded for review/reopen/delete calls.
+- API logging now redacts request/response bodies for `/mistakes` and redacts authorization headers.
+
+Known follow-up:
+
+- Pending mistake ops still use SharedPreferences, now scoped and log-redacted. Move this queue to the existing encrypted/background queue infrastructure in a later hardening task.
+
+Acceptance criteria:
+
+- Existing offline behavior still works.
+- Logged-in users get cross-device mistake notebook state.
+- Failed sync does not lose local entries.
+
+---
+
+## Chunk 4: Unified Pronunciation
+
+### Task 4: Use HuBERT Pronunciation Scoring In Voice Practice
+
+**Files:**
+
+- Modify: `flutter-app/lib/features/voice/data/datasources/voice_remote_datasource.dart`
+- Modify: `flutter-app/lib/features/voice/data/repositories/voice_repository_impl.dart`
+- Modify: `flutter-app/lib/features/voice/domain/entities/pronunciation_score.dart`
+- Test: `flutter-app/test/features/voice/...`
+
+- [ ] **Step 1: Write tests proving HuBERT response is preferred over transcript heuristic**
+- [ ] **Step 2: Add remote call to backend pronunciation endpoint**
+- [ ] **Step 3: Map phoneme scores and error details to domain entity**
+- [ ] **Step 4: Keep transcript heuristic as explicit fallback**
+- [ ] **Step 5: Run voice tests and `flutter analyze`**
+
+Acceptance criteria:
+
+- Voice practice can display phoneme-level feedback when backend returns it.
+- Offline/API-failure scenarios still produce a basic score.
+
+---
+
+## Chunk 5: Server-Side Today Plan
+
+### Task 5: Personalized Today Plan API
+
+**Files:**
+
+- Create: `backend-service/app/schemas/today_plan.py`
+- Create: `backend-service/app/services/today_plan_service.py`
+- Create: `backend-service/app/routes/today_plan.py`
+- Create: `backend-service/tests/test_today_plan_service.py`
+- Modify: `backend-service/app/main.py`
+- Modify: Flutter home today-plan provider/model files after API is available.
+
+- [ ] **Step 1: Write service tests for due vocab, mistakes, weak skills, and streak cases**
+- [ ] **Step 2: Implement backend planner without AI dependency**
+- [ ] **Step 3: Expose authenticated route**
+- [ ] **Step 4: Wire Flutter to use backend plan with local fallback**
+- [ ] **Step 5: Run backend and Flutter focused tests**
+
+Acceptance criteria:
+
+- Plan explains why each item is recommended.
+- Plan has stable IDs and completion states.
+- Flutter still works when backend plan is unavailable.
+
+---
+
+## Chunk 6: CEFR Event Wiring
+
+### Task 6: Record Learning Events Into Proficiency Profile
+
+**Files:**
+
+- Modify: `backend-service/app/routes/learning.py`
+- Modify: `backend-service/app/services/proficiency_service.py`
+- Modify: `flutter-app/lib/features/level/presentation/providers/proficiency_provider.dart`
+- Modify: lesson/game/content completion providers as needed.
+- Test: backend proficiency tests and Flutter flow tests.
+
+- [ ] **Step 1: Identify every completion flow that produces scoreable exercise results**
+- [ ] **Step 2: Add tests for one course lesson, one game, and one content quiz**
+- [ ] **Step 3: Normalize result payloads**
+- [ ] **Step 4: Call proficiency recording after completion**
+- [ ] **Step 5: Run focused tests**
+
+Acceptance criteria:
+
+- CEFR profile changes after real learning activity.
+- Duplicate completions do not inflate progress.
+
+---
+
+## Chunk 7: Premium Enforcement
+
+### Task 7: Backend Entitlements And Premium API Guards
+
+**Files:**
+
+- Create: `backend-service/app/models/entitlement.py`
+- Create: `backend-service/app/schemas/entitlements.py`
+- Create: `backend-service/app/services/entitlement_service.py`
+- Create: `backend-service/app/routes/entitlements.py`
+- Create: `backend-service/alembic/versions/add_entitlements.py`
+- Modify: `backend-service/app/main.py`
+- Modify: premium AI/content routes selected for enforcement.
+- Modify: `flutter-app/lib/core/services/purchases_service.dart`
+
+- [ ] **Step 1: Write entitlement service tests**
+- [ ] **Step 2: Store normalized subscription state**
+- [ ] **Step 3: Add sync endpoint and current-entitlement endpoint**
+- [ ] **Step 4: Add guards around premium server features**
+- [ ] **Step 5: Sync purchase and restore from Flutter**
+- [ ] **Step 6: Run backend tests and `flutter analyze`**
+
+Acceptance criteria:
+
+- Premium access cannot be bypassed by editing Flutter state.
+- Free users receive clear limit/upgrade responses.
+
+---
+
+## Chunk 8: Analytics And CI Completion
+
+### Task 8: Replace Placeholder Analytics And Broaden AI CI
+
+**Files:**
+
+- Modify: `backend-service/app/routes/analytics.py`
+- Modify: `backend-service/app/services/achievement_checker_service.py`
+- Modify: `.github/workflows/ci.yml`
+- Modify: admin analytics pages after backend metrics exist.
+
+- [ ] **Step 1: Write backend analytics tests for retention and skill activity**
+- [ ] **Step 2: Replace retention sample data with DB aggregation**
+- [ ] **Step 3: Replace achievement placeholder stats**
+- [ ] **Step 4: Add an AI service CI test matrix that is broad but time-bounded**
+- [ ] **Step 5: Run backend focused tests and validate workflow syntax**
+
+Acceptance criteria:
+
+- Admin analytics are based on persisted activity.
+- CI catches more AI regressions without making every PR painfully slow.
+
+---
+
+## Operating Checklist
+
+- [ ] Query `code-review-graph` before each new implementation chunk.
+- [ ] Use TDD for each task: failing test, implementation, passing test.
+- [ ] Spawn or simulate `test-writer` review after feature implementations where local tooling allows it.
+- [ ] Spawn or simulate `security-reviewer` for auth, API, DB schema, entitlement, or config changes.
+- [ ] Request code review before PR or after each substantial chunk.
+- [ ] Do not commit until required tests pass.
+- [ ] For backend changes, run focused `pytest`; before commit run broader backend tests when feasible.
+- [ ] For Flutter changes, run `flutter analyze` and focused `flutter test`.
+- [ ] For admin changes, run package tests/build.
diff --git a/flutter-app/assets/i18n/en.json b/flutter-app/assets/i18n/en.json
index 4e44a676..a779b433 100644
--- a/flutter-app/assets/i18n/en.json
+++ b/flutter-app/assets/i18n/en.json
@@ -31,7 +31,8 @@
     "rename": "Rename",
     "play": "Play",
     "awesome": "Awesome!",
-    "create": "Create"
+    "create": "Create",
+    "refresh": "Refresh"
   },
   "auth": {
     "login": "Login",
@@ -170,6 +171,49 @@
     "todayProgress": "Today's progress",
     "weeklyStats": "Weekly stats",
     "recommendations": "Recommended for you",
+    "todayPlan": {
+      "title": "Today's Plan",
+      "subtitle": "A focused path through your next best tasks",
+      "footer": "Built from your reviews, courses, skills, and challenges.",
+      "viewAll": "View plan",
+      "heroTitle": "Your study route is ready",
+      "heroSubtitle": "Finish the next small task, then let LexiLingo guide you into the right practice.",
+      "completedSummary": "{completed}/{total} tasks complete",
+      "startNext": "Start next task",
+      "sequenceTitle": "Today's sequence",
+      "vocabularyTitle": "Review vocabulary",
+      "vocabularyCheckSubtitle": "Check if any words are due for review.",
+      "vocabularyDueSubtitle": "{count} words are waiting for review.",
+      "vocabularyDoneSubtitle": "You're caught up on vocabulary today.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Choose a course",
+      "courseFallbackSubtitle": "Pick a CEFR path and start your first lesson.",
+      "courseSubtitle": "Continue your {level} learning path.",
+      "courseMeta": "Course",
+      "courseProgress": "{percent}% done",
+      "skillFallbackTitle": "Practice speaking",
+      "skillFallbackSubtitle": "Warm up with a short pronunciation drill.",
+      "skillTitle": "Strengthen {skill}",
+      "skillSubtitle": "Current estimate: {level}.",
+      "skillMeta": "Skill",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Play a quick game",
+      "challengeFallbackSubtitle": "Earn XP with a short English challenge.",
+      "challengeMeta": "Challenge",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat with Lexi",
+      "lexiSubtitle": "Close the loop with a short AI conversation.",
+      "lexiMeta": "AI Tutor",
+      "reviewAction": "Review",
+      "checkAction": "Check",
+      "browseAction": "Browse",
+      "continueAction": "Continue",
+      "practiceAction": "Practice",
+      "playAction": "Play",
+      "startAction": "Start",
+      "doneAction": "Done",
+      "chatAction": "Chat"
+    },
     "loadingChallenges": "Loading challenges...",
     "dailyChallenges": "Daily Challenges",
     "challengesCompleted": "{completed}/{total} completed",
@@ -756,13 +800,156 @@
     "adverb": "Adverb",
     "pronunciation": "Pronunciation"
   },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Manage cache and pending sync",
+    "entrySubtitle": "Review offline data, cache, and queued updates",
+    "onlineTitle": "You are online",
+    "onlineSubtitle": "Fresh content and queued changes can sync normally.",
+    "offlineTitle": "You are offline",
+    "offlineSubtitle": "Cached content can still open; new changes may wait in the queue.",
+    "cacheTitle": "API cache",
+    "cacheSubtitle": "Cached content used for faster loading and offline fallback.",
+    "totalEntries": "Total entries",
+    "noCache": "No cached API responses yet.",
+    "clearExpired": "Clear expired",
+    "clearAll": "Clear all",
+    "clearAllTitle": "Clear all cached API data?",
+    "clearAllMessage": "This removes cached public content. Your account, saved progress, and pending sync queue are not deleted.",
+    "clearAllConfirm": "Clear cache",
+    "expiredCleared": "Cleared {count} expired cache entries.",
+    "allCacheCleared": "All API cache entries were cleared.",
+    "queueTitle": "Sync queue",
+    "queueSubtitle": "Pending offline actions waiting to be sent.",
+    "totalQueued": "Total queued",
+    "readyQueued": "Ready now",
+    "scheduledQueued": "Scheduled retry",
+    "retryingQueued": "Retrying",
+    "queueHint": "Queued work is processed automatically when the app is online and the account is active.",
+    "queueUnavailable": "Persistent sync queue is not available on this platform.",
+    "noUserScope": "Sign in to see account-scoped sync queue status.",
+    "loadFailed": "Could not load offline status",
+    "cacheTypes": {
+      "news": "News",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Books",
+      "dictionary": "Dictionary",
+      "game": "Games",
+      "flashcard": "Flashcards"
+    }
+  },
+  "practiceLab": {
+    "title": "Practice Lab",
+    "shortTitle": "Practice",
+    "heroTitle": "Train by skill",
+    "heroSubtitle": "Pick the exact skill you want to sharpen, or follow the focus areas from your CEFR profile.",
+    "currentLevel": "Current level",
+    "recommended": "Focus skills",
+    "recommendedTitle": "Recommended practice",
+    "recommendedSubtitle": "Based on your weakest proficiency scores.",
+    "fallbackSubtitle": "Practice a balanced mix while LexiLingo learns your strengths.",
+    "allSkillsTitle": "All skill labs",
+    "allSkillsSubtitle": "Jump into a focused practice mode using existing lessons, games, audio, and Lexi.",
+    "focus": "Focus",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Unlock advanced Lexi-guided writing practice with Premium.",
+    "unlockPremium": "Unlock Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Vocabulary",
+        "subtitle": "Review due words and strengthen recall.",
+        "action": "Review words",
+        "estimate": "5-8 min"
+      },
+      "speaking": {
+        "title": "Speaking",
+        "subtitle": "Practice pronunciation and spoken responses.",
+        "action": "Speak now",
+        "estimate": "6-10 min"
+      },
+      "listening": {
+        "title": "Listening",
+        "subtitle": "Train your ear with graded podcast content.",
+        "action": "Listen",
+        "estimate": "8-12 min"
+      },
+      "reading": {
+        "title": "Reading",
+        "subtitle": "Read CEFR-graded news and check comprehension.",
+        "action": "Read",
+        "estimate": "7-10 min"
+      },
+      "grammar": {
+        "title": "Grammar",
+        "subtitle": "Use games and quizzes to reinforce structure.",
+        "action": "Practice",
+        "estimate": "5-9 min"
+      },
+      "writing": {
+        "title": "Writing",
+        "subtitle": "Draft sentences with Lexi and refine your output.",
+        "action": "Open Lexi",
+        "estimate": "6-10 min"
+      },
+      "mistakes": {
+        "title": "Mistake Notebook",
+        "subtitle": "Review questions you missed in reading quizzes.",
+        "action": "Review mistakes",
+        "estimate": "4-8 min"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Mistake Notebook",
+    "heroTitle": "Turn misses into review",
+    "heroSubtitle": "Wrong answers from book and news quizzes are saved here for quick follow-up.",
+    "total": "Total",
+    "toReview": "To review",
+    "reviewed": "Reviewed",
+    "reviewedTimes": "Reviewed {count} times",
+    "filterAll": "All",
+    "filterToReview": "To review",
+    "filterReviewed": "Reviewed",
+    "emptyTitle": "No mistakes yet",
+    "emptySubtitle": "Missed quiz answers from Books and News will appear here automatically.",
+    "emptyFilterTitle": "Nothing in this filter",
+    "emptyFilterSubtitle": "Switch filters to see the rest of your notebook.",
+    "sourceBookQuiz": "Book quiz",
+    "sourceNewsQuiz": "News quiz",
+    "sourceFillBlank": "Fill in the Blank",
+    "sourceGrammarQuiz": "Grammar Quiz",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Your answer",
+    "correctAnswer": "Correct answer",
+    "explanation": "Explanation",
+    "markReviewed": "Mark reviewed",
+    "delete": "Delete",
+    "deleteTitle": "Delete mistake?",
+    "deleteMessage": "This removes the item from your notebook."
+  },
   "assessment": {
     "placementTest": "Placement test",
     "cefrLevel": "CEFR Level",
     "readingSpeed": "Reading speed",
     "retakeTest": "Retake test",
     "yourLevelIs": "Your level is {level}",
-    "testCompleted": "Test completed"
+    "testCompleted": "Test completed",
+    "questionCounter": "Question {current} of {total}",
+    "answeredCount": "{answered}/{total} answered",
+    "points": "{points} pts",
+    "previous": "Previous",
+    "next": "Next",
+    "submitTest": "Submit test",
+    "answerAllQuestions": "Answer every question before submitting.",
+    "resultSubtitle": "Your CEFR profile has been updated from this assessment.",
+    "score": "Score",
+    "correct": "Correct",
+    "rank": "Rank",
+    "loadFailed": "Could not load the test",
+    "noQuestions": "No questions available",
+    "noQuestionsSubtitle": "Try again in a moment."
   },
   "premium": {
     "title": "Go Premium",
@@ -1204,11 +1391,32 @@
     "topicScienceSubtitle": "Concepts & Discoveries",
     "topicTechnology": "Technology",
     "topicTechnologySubtitle": "Software & Digital Age",
-    "noDefinitionYet": "No definition available yet"
+    "noDefinitionYet": "No definition available yet",
+    "vietnameseLabel": "Vietnamese"
   },
   "legal": {
     "privacy_title": "Privacy Policy",
     "terms_title": "Terms of Service",
     "last_updated": "Last updated: {date}"
+  },
+  "vocabQuiz": {
+    "title": "Vocabulary Quiz",
+    "loading": "Building your quiz...",
+    "empty": "No words due for review!",
+    "tryAgain": "Try again",
+    "term": "TERM",
+    "definition": "DEFINITION",
+    "chooseCorrect": "Choose the correct answer",
+    "continueLabel": "Continue",
+    "finish": "Finish",
+    "correct": "Correct!",
+    "incorrect": "Not quite",
+    "exitTitle": "Exit quiz?",
+    "exitMessage": "Your progress so far is saved. Are you sure you want to exit?",
+    "chooseMode": "Choose a review mode",
+    "modeQuizTitle": "Multiple-choice quiz",
+    "modeQuizSubtitle": "Test meaning and term — auto-graded",
+    "modeFlashcardTitle": "Flashcards",
+    "modeFlashcardSubtitle": "Flip cards and rate yourself"
   }
 }
diff --git a/flutter-app/assets/i18n/es.json b/flutter-app/assets/i18n/es.json
index be3dea1e..02f0ca0a 100644
--- a/flutter-app/assets/i18n/es.json
+++ b/flutter-app/assets/i18n/es.json
@@ -31,7 +31,8 @@
     "rename": "Rebautizar",
     "play": "Jugar",
     "awesome": "¡Impresionante!",
-    "create": "Crear"
+    "create": "Crear",
+    "refresh": "Actualizar"
   },
   "auth": {
     "login": "Iniciar sesión",
@@ -208,7 +209,50 @@
     "pointsCalendar": "Calendario de Puntos",
     "setupCheckinReminder": "Configurar recordatorio de entrada",
     "checkinReminder": "Recordatorio de entrada",
-    "setTime": "Establecer hora"
+    "setTime": "Establecer hora",
+    "todayPlan": {
+      "title": "Today's Plan",
+      "subtitle": "A focused path through your next best tasks",
+      "footer": "Built from your reviews, courses, skills, and challenges.",
+      "viewAll": "View plan",
+      "heroTitle": "Your study route is ready",
+      "heroSubtitle": "Finish the next small task, then let LexiLingo guide you into the right practice.",
+      "completedSummary": "{completed}/{total} tasks complete",
+      "startNext": "Start next task",
+      "sequenceTitle": "Today's sequence",
+      "vocabularyTitle": "Review vocabulary",
+      "vocabularyCheckSubtitle": "Check if any words are due for review.",
+      "vocabularyDueSubtitle": "{count} words are waiting for review.",
+      "vocabularyDoneSubtitle": "You're caught up on vocabulary today.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Choose a course",
+      "courseFallbackSubtitle": "Pick a CEFR path and start your first lesson.",
+      "courseSubtitle": "Continue your {level} learning path.",
+      "courseMeta": "Course",
+      "courseProgress": "{percent}% done",
+      "skillFallbackTitle": "Practice speaking",
+      "skillFallbackSubtitle": "Warm up with a short pronunciation drill.",
+      "skillTitle": "Strengthen {skill}",
+      "skillSubtitle": "Current estimate: {level}.",
+      "skillMeta": "Skill",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Play a quick game",
+      "challengeFallbackSubtitle": "Earn XP with a short English challenge.",
+      "challengeMeta": "Challenge",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat with Lexi",
+      "lexiSubtitle": "Close the loop with a short AI conversation.",
+      "lexiMeta": "AI Tutor",
+      "reviewAction": "Review",
+      "checkAction": "Check",
+      "browseAction": "Browse",
+      "continueAction": "Continue",
+      "practiceAction": "Practice",
+      "playAction": "Play",
+      "startAction": "Start",
+      "doneAction": "Done",
+      "chatAction": "Chat"
+    }
   },
   "course": {
     "title": "Cursos",
@@ -357,7 +401,10 @@
     "playbackSpeedDescription": "Ajustar la velocidad de reproducción de audio de texto a voz",
     "selectPlaybackSpeed": "Seleccione la velocidad de reproducción",
     "confidence": "Confianza: {percent}%",
-    "playError": "No se pudo reproducir: {error}"
+    "playError": "No se pudo reproducir: {error}",
+    "tapToRecord": "Tap to record",
+    "tapToStop": "Tap to stop",
+    "assessmentFailed": "Pronunciation assessment failed. Please try again."
   },
   "chat": {
     "placeholder": "Escribe un mensaje...",
@@ -619,7 +666,19 @@
     "earnTipFinishCourse": "Terminar un curso",
     "earnTipStreakBonus": "Bono de racha diaria",
     "earnTipAchievements": "Desbloquear logros",
-    "earnTipChallenges": "Desafíos semanales"
+    "earnTipChallenges": "Desafíos semanales",
+    "dailyStreakRewardAvailable": "Daily Streak Reward!",
+    "dailyStreakRewardSubtitle": "You've kept your streak alive! Claim your daily reward now.",
+    "claimDailyRewardButton": "Claim Daily Reward",
+    "dailyRewardClaimed": "Daily Reward Claimed!",
+    "gemsReceived": "You received {gems} gems!",
+    "starterReward": {
+      "title": "Welcome gift!",
+      "description": "Use Gems to unlock special items in the shop.",
+      "action": "Awesome!",
+      "gemLabel": "Gem reward",
+      "confirmation": "{gems} Gems were added to your wallet."
+    }
   },
   "social": {
     "friends": "Amigos",
@@ -668,7 +727,29 @@
     "skipTour": "Saltar guía",
     "activeUsers": "Usuarios activos",
     "dailyLessons": "Lecciones diarias",
-    "globalCommunity": "Únete a una comunidad global"
+    "globalCommunity": "Únete a una comunidad global",
+    "personalizeTitle": "Personaliza tu aprendizaje",
+    "goalQuestion": "¿Cuál es tu objetivo?",
+    "goalSubtitle": "Adaptaremos tu experiencia de aprendizaje según tu elección.",
+    "levelQuestion": "¿Cuál es tu nivel actual?",
+    "levelSubtitle": "Esto nos ayuda a ajustar la dificultad del contenido desde el inicio.",
+    "interestQuestion": "¿Qué temas te gustan más?",
+    "interestSubtitle": "Priorizaremos las lecciones según tus intereses.",
+    "continueBtn": "Continuar",
+    "createPlan": "Crear mi plan",
+    "goalCareer": "Carrera",
+    "goalTravel": "Viajes",
+    "goalExams": "Exámenes",
+    "goalCulture": "Cultura",
+    "levelA1": "A1 - Principiante",
+    "levelA2": "A2 - Elemental",
+    "levelB1": "B1 - Intermedio",
+    "levelB2": "B2 - Intermedio alto",
+    "levelC1": "C1 - Avanzado",
+    "interestDailyLife": "Vida diaria y temas sociales",
+    "interestTechnology": "Tecnología e innovación",
+    "interestCulture": "Cultura y entretenimiento",
+    "interestCareer": "Crecimiento profesional y entrevistas"
   },
   "preAuth": {
     "quickSetup": "Configuración rápida",
@@ -725,7 +806,21 @@
     "readingSpeed": "Velocidad de lectura",
     "retakeTest": "Repetir prueba",
     "yourLevelIs": "Tu nivel es {level}",
-    "testCompleted": "Prueba completada"
+    "testCompleted": "Prueba completada",
+    "questionCounter": "Question {current} of {total}",
+    "answeredCount": "{answered}/{total} answered",
+    "points": "{points} pts",
+    "previous": "Previous",
+    "next": "Next",
+    "submitTest": "Submit test",
+    "answerAllQuestions": "Answer every question before submitting.",
+    "resultSubtitle": "Your CEFR profile has been updated from this assessment.",
+    "score": "Score",
+    "correct": "Correct",
+    "rank": "Rank",
+    "loadFailed": "Could not load the test",
+    "noQuestions": "No questions available",
+    "noQuestionsSubtitle": "Try again in a moment."
   },
   "premium": {
     "title": "(Premium) Go Premium",
@@ -777,7 +872,10 @@
     "categoryPowerUps": "Potenciadores",
     "categoryBoosts": "Impulsa",
     "categoryCosmetics": "Productos cosméticos",
-    "categorySpecial": "Especial"
+    "categorySpecial": "Especial",
+    "equipNow": "Equip now",
+    "avatarEquipped": "Avatar equipped successfully!",
+    "avatarEquipFailed": "Could not equip this avatar."
   },
   "leaderboard": {
     "title": "Tabla de clasificación",
@@ -867,7 +965,9 @@
     "streakLabel": "Racha",
     "streakBonusLabel": "Bonificación por racha: {multiplier}x",
     "playAgainButton": "Jugar de nuevo",
-    "backToGamesButton": "Volver a Juegos"
+    "backToGamesButton": "Volver a Juegos",
+    "xpNotAwarded": "XP was not awarded. Your game result is preserved.",
+    "retryXp": "Retry XP award"
   },
   "spellingBee": {
     "wordProgress": "Palabra {current}/{total}",
@@ -877,7 +977,15 @@
     "correctFeedback": "¡Correcto!",
     "answerRevealLabel": "La respuesta fue:",
     "nextWordButton": "siguiente palabra",
-    "seeResultsButton": "Ver resultados"
+    "seeResultsButton": "Ver resultados",
+    "audioError": "Could not play audio. Check your connection.",
+    "retryAudio": "Retry",
+    "listenButtonLabel": "Listen to the word",
+    "noPlaysLeft": "No plays remaining",
+    "abandonTitle": "Quit game?",
+    "abandonBody": "XP will be based on words answered correctly so far.",
+    "keepPlaying": "Keep playing",
+    "quit": "Quit"
   },
   "wordScramble": {
     "wordProgress": "Palabra {current} de {total}",
@@ -1045,7 +1153,10 @@
     "unlockGoldenChest": "Cofre dorado",
     "unlockGems": "50 gemas",
     "unlockXpBooster": "Potenciador XP x2",
-    "continueJourney": "Continuar viaje"
+    "continueJourney": "Continuar viaje",
+    "loadFailed": "Unable to load this game. Please try again.",
+    "emptyGame": "This game has no playable content right now.",
+    "retryLoad": "Try again"
   },
   "learning": {
     "checkAnswer": "Verificar respuesta",
@@ -1072,7 +1183,8 @@
     "backToBook": "Volver a Reservar",
     "readerSettings": "Configuración del lector",
     "pageProgress": "Página {current} de {total}",
-    "searchPlaceholder": "Buscar por título o autor..."
+    "searchPlaceholder": "Buscar por título o autor...",
+    "savedBooks": "Libros guardados"
   },
   "news": {
     "title": "noticias en ingles",
@@ -1146,11 +1258,165 @@
     "topicScienceSubtitle": "Conceptos y descubrimientos",
     "topicTechnology": "Tecnología",
     "topicTechnologySubtitle": "Software y era digital",
-    "noDefinitionYet": "Definición no disponible aún"
+    "noDefinitionYet": "Definición no disponible aún",
+    "translationLabel": "Traducción",
+    "tabWords": "Words",
+    "tabTopics": "Topic Flashcards",
+    "startLearning": "Start",
+    "audioQuestionHint": "Listen and guess the word"
   },
   "legal": {
     "privacy_title": "Política de privacidad",
     "terms_title": "Términos de servicio",
     "last_updated": "Última actualización: {date}"
+  },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Manage cache and pending sync",
+    "entrySubtitle": "Review offline data, cache, and queued updates",
+    "onlineTitle": "You are online",
+    "onlineSubtitle": "Fresh content and queued changes can sync normally.",
+    "offlineTitle": "You are offline",
+    "offlineSubtitle": "Cached content can still open; new changes may wait in the queue.",
+    "cacheTitle": "API cache",
+    "cacheSubtitle": "Cached content used for faster loading and offline fallback.",
+    "totalEntries": "Total entries",
+    "noCache": "No cached API responses yet.",
+    "clearExpired": "Clear expired",
+    "clearAll": "Clear all",
+    "clearAllTitle": "Clear all cached API data?",
+    "clearAllMessage": "This removes cached public content. Your account, saved progress, and pending sync queue are not deleted.",
+    "clearAllConfirm": "Clear cache",
+    "expiredCleared": "Cleared {count} expired cache entries.",
+    "allCacheCleared": "All API cache entries were cleared.",
+    "queueTitle": "Sync queue",
+    "queueSubtitle": "Pending offline actions waiting to be sent.",
+    "totalQueued": "Total queued",
+    "readyQueued": "Ready now",
+    "scheduledQueued": "Scheduled retry",
+    "retryingQueued": "Retrying",
+    "queueHint": "Queued work is processed automatically when the app is online and the account is active.",
+    "queueUnavailable": "Persistent sync queue is not available on this platform.",
+    "noUserScope": "Sign in to see account-scoped sync queue status.",
+    "loadFailed": "Could not load offline status",
+    "cacheTypes": {
+      "news": "News",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Books",
+      "dictionary": "Dictionary",
+      "game": "Games",
+      "flashcard": "Flashcards"
+    }
+  },
+  "practiceLab": {
+    "title": "Practice Lab",
+    "shortTitle": "Practice",
+    "heroTitle": "Train by skill",
+    "heroSubtitle": "Pick the exact skill you want to sharpen, or follow the focus areas from your CEFR profile.",
+    "currentLevel": "Current level",
+    "recommended": "Focus skills",
+    "recommendedTitle": "Recommended practice",
+    "recommendedSubtitle": "Based on your weakest proficiency scores.",
+    "fallbackSubtitle": "Practice a balanced mix while LexiLingo learns your strengths.",
+    "allSkillsTitle": "All skill labs",
+    "allSkillsSubtitle": "Jump into a focused practice mode using existing lessons, games, audio, and Lexi.",
+    "focus": "Focus",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Unlock advanced Lexi-guided writing practice with Premium.",
+    "unlockPremium": "Unlock Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Vocabulary",
+        "subtitle": "Review due words and strengthen recall.",
+        "action": "Review words",
+        "estimate": "5-8 min"
+      },
+      "speaking": {
+        "title": "Speaking",
+        "subtitle": "Practice pronunciation and spoken responses.",
+        "action": "Speak now",
+        "estimate": "6-10 min"
+      },
+      "listening": {
+        "title": "Listening",
+        "subtitle": "Train your ear with graded podcast content.",
+        "action": "Listen",
+        "estimate": "8-12 min"
+      },
+      "reading": {
+        "title": "Reading",
+        "subtitle": "Read CEFR-graded news and check comprehension.",
+        "action": "Read",
+        "estimate": "7-10 min"
+      },
+      "grammar": {
+        "title": "Grammar",
+        "subtitle": "Use games and quizzes to reinforce structure.",
+        "action": "Practice",
+        "estimate": "5-9 min"
+      },
+      "writing": {
+        "title": "Writing",
+        "subtitle": "Draft sentences with Lexi and refine your output.",
+        "action": "Open Lexi",
+        "estimate": "6-10 min"
+      },
+      "mistakes": {
+        "title": "Mistake Notebook",
+        "subtitle": "Review questions you missed in reading quizzes.",
+        "action": "Review mistakes",
+        "estimate": "4-8 min"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Mistake Notebook",
+    "heroTitle": "Turn misses into review",
+    "heroSubtitle": "Wrong answers from book and news quizzes are saved here for quick follow-up.",
+    "total": "Total",
+    "toReview": "To review",
+    "reviewed": "Reviewed",
+    "reviewedTimes": "Reviewed {count} times",
+    "filterAll": "All",
+    "filterToReview": "To review",
+    "filterReviewed": "Reviewed",
+    "emptyTitle": "No mistakes yet",
+    "emptySubtitle": "Missed quiz answers from Books and News will appear here automatically.",
+    "emptyFilterTitle": "Nothing in this filter",
+    "emptyFilterSubtitle": "Switch filters to see the rest of your notebook.",
+    "sourceBookQuiz": "Book quiz",
+    "sourceNewsQuiz": "News quiz",
+    "sourceFillBlank": "Fill in the Blank",
+    "sourceGrammarQuiz": "Grammar Quiz",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Your answer",
+    "correctAnswer": "Correct answer",
+    "explanation": "Explanation",
+    "markReviewed": "Mark reviewed",
+    "delete": "Delete",
+    "deleteTitle": "Delete mistake?",
+    "deleteMessage": "This removes the item from your notebook."
+  },
+  "vocabQuiz": {
+    "title": "Vocabulary Quiz",
+    "loading": "Building your quiz...",
+    "empty": "No words due for review!",
+    "tryAgain": "Try again",
+    "term": "TERM",
+    "definition": "DEFINITION",
+    "chooseCorrect": "Choose the correct answer",
+    "continueLabel": "Continue",
+    "finish": "Finish",
+    "correct": "Correct!",
+    "incorrect": "Not quite",
+    "exitTitle": "Exit quiz?",
+    "exitMessage": "Your progress so far is saved. Are you sure you want to exit?",
+    "chooseMode": "Choose a review mode",
+    "modeQuizTitle": "Multiple-choice quiz",
+    "modeQuizSubtitle": "Test meaning and term — auto-graded",
+    "modeFlashcardTitle": "Flashcards",
+    "modeFlashcardSubtitle": "Flip cards and rate yourself"
   }
 }
diff --git a/flutter-app/assets/i18n/fr.json b/flutter-app/assets/i18n/fr.json
index 8dc30a1f..ff96cbd4 100644
--- a/flutter-app/assets/i18n/fr.json
+++ b/flutter-app/assets/i18n/fr.json
@@ -31,7 +31,8 @@
     "rename": "Rebaptiser",
     "play": "Jouer",
     "awesome": "Génial!",
-    "create": "Créer"
+    "create": "Créer",
+    "refresh": "Actualiser"
   },
   "auth": {
     "login": "Connexion",
@@ -208,7 +209,50 @@
     "pointsCalendar": "Calendrier des Points",
     "setupCheckinReminder": "Configurer le rappel",
     "checkinReminder": "Rappel de pointage",
-    "setTime": "Définir l'heure"
+    "setTime": "Définir l'heure",
+    "todayPlan": {
+      "title": "Today's Plan",
+      "subtitle": "A focused path through your next best tasks",
+      "footer": "Built from your reviews, courses, skills, and challenges.",
+      "viewAll": "View plan",
+      "heroTitle": "Your study route is ready",
+      "heroSubtitle": "Finish the next small task, then let LexiLingo guide you into the right practice.",
+      "completedSummary": "{completed}/{total} tasks complete",
+      "startNext": "Start next task",
+      "sequenceTitle": "Today's sequence",
+      "vocabularyTitle": "Review vocabulary",
+      "vocabularyCheckSubtitle": "Check if any words are due for review.",
+      "vocabularyDueSubtitle": "{count} words are waiting for review.",
+      "vocabularyDoneSubtitle": "You're caught up on vocabulary today.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Choose a course",
+      "courseFallbackSubtitle": "Pick a CEFR path and start your first lesson.",
+      "courseSubtitle": "Continue your {level} learning path.",
+      "courseMeta": "Course",
+      "courseProgress": "{percent}% done",
+      "skillFallbackTitle": "Practice speaking",
+      "skillFallbackSubtitle": "Warm up with a short pronunciation drill.",
+      "skillTitle": "Strengthen {skill}",
+      "skillSubtitle": "Current estimate: {level}.",
+      "skillMeta": "Skill",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Play a quick game",
+      "challengeFallbackSubtitle": "Earn XP with a short English challenge.",
+      "challengeMeta": "Challenge",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat with Lexi",
+      "lexiSubtitle": "Close the loop with a short AI conversation.",
+      "lexiMeta": "AI Tutor",
+      "reviewAction": "Review",
+      "checkAction": "Check",
+      "browseAction": "Browse",
+      "continueAction": "Continue",
+      "practiceAction": "Practice",
+      "playAction": "Play",
+      "startAction": "Start",
+      "doneAction": "Done",
+      "chatAction": "Chat"
+    }
   },
   "course": {
     "title": "Cours",
@@ -357,7 +401,10 @@
     "playbackSpeedDescription": "Ajuster la vitesse de lecture audio de synthèse vocale",
     "selectPlaybackSpeed": "Sélectionnez la vitesse de lecture",
     "confidence": "Confiance : {percent} %",
-    "playError": "Échec de la lecture : {error}"
+    "playError": "Échec de la lecture : {error}",
+    "tapToRecord": "Tap to record",
+    "tapToStop": "Tap to stop",
+    "assessmentFailed": "Pronunciation assessment failed. Please try again."
   },
   "chat": {
     "placeholder": "Tapez un message...",
@@ -619,7 +666,19 @@
     "earnTipFinishCourse": "Terminer un cours",
     "earnTipStreakBonus": "Bonus de série quotidienne",
     "earnTipAchievements": "Débloquer des succès",
-    "earnTipChallenges": "Défis hebdomadaires"
+    "earnTipChallenges": "Défis hebdomadaires",
+    "dailyStreakRewardAvailable": "Daily Streak Reward!",
+    "dailyStreakRewardSubtitle": "You've kept your streak alive! Claim your daily reward now.",
+    "claimDailyRewardButton": "Claim Daily Reward",
+    "dailyRewardClaimed": "Daily Reward Claimed!",
+    "gemsReceived": "You received {gems} gems!",
+    "starterReward": {
+      "title": "Welcome gift!",
+      "description": "Use Gems to unlock special items in the shop.",
+      "action": "Awesome!",
+      "gemLabel": "Gem reward",
+      "confirmation": "{gems} Gems were added to your wallet."
+    }
   },
   "social": {
     "friends": "Amis",
@@ -668,7 +727,29 @@
     "skipTour": "Ignorer la visite",
     "activeUsers": "Utilisateurs actifs",
     "dailyLessons": "Leçons quotidiennes",
-    "globalCommunity": "Rejoignez une communauté mondiale"
+    "globalCommunity": "Rejoignez une communauté mondiale",
+    "personalizeTitle": "Personnalisez votre apprentissage",
+    "goalQuestion": "Quel est votre objectif ?",
+    "goalSubtitle": "Nous adapterons votre expérience d’apprentissage à votre choix.",
+    "levelQuestion": "Quel est votre niveau actuel ?",
+    "levelSubtitle": "Cela nous aide à définir la difficulté du contenu dès le départ.",
+    "interestQuestion": "Quels sujets vous intéressent le plus ?",
+    "interestSubtitle": "Nous donnerons la priorité aux leçons liées à vos centres d’intérêt.",
+    "continueBtn": "Continuer",
+    "createPlan": "Créer mon plan",
+    "goalCareer": "Carrière",
+    "goalTravel": "Voyage",
+    "goalExams": "Examens",
+    "goalCulture": "Culture",
+    "levelA1": "A1 - Débutant",
+    "levelA2": "A2 - Élémentaire",
+    "levelB1": "B1 - Intermédiaire",
+    "levelB2": "B2 - Intermédiaire supérieur",
+    "levelC1": "C1 - Avancé",
+    "interestDailyLife": "Vie quotidienne et sujets sociaux",
+    "interestTechnology": "Technologie et innovation",
+    "interestCulture": "Culture et divertissement",
+    "interestCareer": "Évolution de carrière et entretiens"
   },
   "preAuth": {
     "quickSetup": "Configuration rapide",
@@ -725,7 +806,21 @@
     "readingSpeed": "Vitesse de lecture",
     "retakeTest": "Repasser le test",
     "yourLevelIs": "Votre niveau est {level}",
-    "testCompleted": "Test terminé"
+    "testCompleted": "Test terminé",
+    "questionCounter": "Question {current} of {total}",
+    "answeredCount": "{answered}/{total} answered",
+    "points": "{points} pts",
+    "previous": "Previous",
+    "next": "Next",
+    "submitTest": "Submit test",
+    "answerAllQuestions": "Answer every question before submitting.",
+    "resultSubtitle": "Your CEFR profile has been updated from this assessment.",
+    "score": "Score",
+    "correct": "Correct",
+    "rank": "Rank",
+    "loadFailed": "Could not load the test",
+    "noQuestions": "No questions available",
+    "noQuestionsSubtitle": "Try again in a moment."
   },
   "premium": {
     "title": "(Premium) Go Premium",
@@ -777,7 +872,10 @@
     "categoryPowerUps": "Mises sous tension",
     "categoryBoosts": "Booste",
     "categoryCosmetics": "Produits de beauté",
-    "categorySpecial": "Spécial"
+    "categorySpecial": "Spécial",
+    "equipNow": "Equip now",
+    "avatarEquipped": "Avatar equipped successfully!",
+    "avatarEquipFailed": "Could not equip this avatar."
   },
   "leaderboard": {
     "title": "Classement",
@@ -867,7 +965,9 @@
     "streakLabel": "Traînée",
     "streakBonusLabel": "Bonus de séquence : {multiplier}x",
     "playAgainButton": "Rejouer",
-    "backToGamesButton": "Retour aux jeux"
+    "backToGamesButton": "Retour aux jeux",
+    "xpNotAwarded": "XP was not awarded. Your game result is preserved.",
+    "retryXp": "Retry XP award"
   },
   "spellingBee": {
     "wordProgress": "Mot {current}/{total}",
@@ -877,7 +977,15 @@
     "correctFeedback": "Correct!",
     "answerRevealLabel": "La réponse était :",
     "nextWordButton": "Mot suivant",
-    "seeResultsButton": "Voir les résultats"
+    "seeResultsButton": "Voir les résultats",
+    "audioError": "Could not play audio. Check your connection.",
+    "retryAudio": "Retry",
+    "listenButtonLabel": "Listen to the word",
+    "noPlaysLeft": "No plays remaining",
+    "abandonTitle": "Quit game?",
+    "abandonBody": "XP will be based on words answered correctly so far.",
+    "keepPlaying": "Keep playing",
+    "quit": "Quit"
   },
   "wordScramble": {
     "wordProgress": "Mot {current} de {total}",
@@ -1045,7 +1153,10 @@
     "unlockGoldenChest": "Coffre doré",
     "unlockGems": "50 gemmes",
     "unlockXpBooster": "Boost XP x2",
-    "continueJourney": "Continuer"
+    "continueJourney": "Continuer",
+    "loadFailed": "Unable to load this game. Please try again.",
+    "emptyGame": "This game has no playable content right now.",
+    "retryLoad": "Try again"
   },
   "learning": {
     "checkAnswer": "Vérifier la réponse",
@@ -1072,7 +1183,8 @@
     "backToBook": "Retour au livre",
     "readerSettings": "Paramètres du lecteur",
     "pageProgress": "Page {current} de {total}",
-    "searchPlaceholder": "Rechercher par titre ou auteur..."
+    "searchPlaceholder": "Rechercher par titre ou auteur...",
+    "savedBooks": "Livres enregistrés"
   },
   "news": {
     "title": "Actualités en anglais",
@@ -1146,11 +1258,165 @@
     "topicScienceSubtitle": "Concepts et découvertes",
     "topicTechnology": "Technologie",
     "topicTechnologySubtitle": "Logiciels et ère numérique",
-    "noDefinitionYet": "Définition non disponible"
+    "noDefinitionYet": "Définition non disponible",
+    "translationLabel": "Traduction",
+    "tabWords": "Words",
+    "tabTopics": "Topic Flashcards",
+    "startLearning": "Start",
+    "audioQuestionHint": "Listen and guess the word"
   },
   "legal": {
     "privacy_title": "Politique de confidentialité",
     "terms_title": "Conditions d'utilisation",
     "last_updated": "Dernière mise à jour : {date}"
+  },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Manage cache and pending sync",
+    "entrySubtitle": "Review offline data, cache, and queued updates",
+    "onlineTitle": "You are online",
+    "onlineSubtitle": "Fresh content and queued changes can sync normally.",
+    "offlineTitle": "You are offline",
+    "offlineSubtitle": "Cached content can still open; new changes may wait in the queue.",
+    "cacheTitle": "API cache",
+    "cacheSubtitle": "Cached content used for faster loading and offline fallback.",
+    "totalEntries": "Total entries",
+    "noCache": "No cached API responses yet.",
+    "clearExpired": "Clear expired",
+    "clearAll": "Clear all",
+    "clearAllTitle": "Clear all cached API data?",
+    "clearAllMessage": "This removes cached public content. Your account, saved progress, and pending sync queue are not deleted.",
+    "clearAllConfirm": "Clear cache",
+    "expiredCleared": "Cleared {count} expired cache entries.",
+    "allCacheCleared": "All API cache entries were cleared.",
+    "queueTitle": "Sync queue",
+    "queueSubtitle": "Pending offline actions waiting to be sent.",
+    "totalQueued": "Total queued",
+    "readyQueued": "Ready now",
+    "scheduledQueued": "Scheduled retry",
+    "retryingQueued": "Retrying",
+    "queueHint": "Queued work is processed automatically when the app is online and the account is active.",
+    "queueUnavailable": "Persistent sync queue is not available on this platform.",
+    "noUserScope": "Sign in to see account-scoped sync queue status.",
+    "loadFailed": "Could not load offline status",
+    "cacheTypes": {
+      "news": "News",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Books",
+      "dictionary": "Dictionary",
+      "game": "Games",
+      "flashcard": "Flashcards"
+    }
+  },
+  "practiceLab": {
+    "title": "Practice Lab",
+    "shortTitle": "Practice",
+    "heroTitle": "Train by skill",
+    "heroSubtitle": "Pick the exact skill you want to sharpen, or follow the focus areas from your CEFR profile.",
+    "currentLevel": "Current level",
+    "recommended": "Focus skills",
+    "recommendedTitle": "Recommended practice",
+    "recommendedSubtitle": "Based on your weakest proficiency scores.",
+    "fallbackSubtitle": "Practice a balanced mix while LexiLingo learns your strengths.",
+    "allSkillsTitle": "All skill labs",
+    "allSkillsSubtitle": "Jump into a focused practice mode using existing lessons, games, audio, and Lexi.",
+    "focus": "Focus",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Unlock advanced Lexi-guided writing practice with Premium.",
+    "unlockPremium": "Unlock Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Vocabulary",
+        "subtitle": "Review due words and strengthen recall.",
+        "action": "Review words",
+        "estimate": "5-8 min"
+      },
+      "speaking": {
+        "title": "Speaking",
+        "subtitle": "Practice pronunciation and spoken responses.",
+        "action": "Speak now",
+        "estimate": "6-10 min"
+      },
+      "listening": {
+        "title": "Listening",
+        "subtitle": "Train your ear with graded podcast content.",
+        "action": "Listen",
+        "estimate": "8-12 min"
+      },
+      "reading": {
+        "title": "Reading",
+        "subtitle": "Read CEFR-graded news and check comprehension.",
+        "action": "Read",
+        "estimate": "7-10 min"
+      },
+      "grammar": {
+        "title": "Grammar",
+        "subtitle": "Use games and quizzes to reinforce structure.",
+        "action": "Practice",
+        "estimate": "5-9 min"
+      },
+      "writing": {
+        "title": "Writing",
+        "subtitle": "Draft sentences with Lexi and refine your output.",
+        "action": "Open Lexi",
+        "estimate": "6-10 min"
+      },
+      "mistakes": {
+        "title": "Mistake Notebook",
+        "subtitle": "Review questions you missed in reading quizzes.",
+        "action": "Review mistakes",
+        "estimate": "4-8 min"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Mistake Notebook",
+    "heroTitle": "Turn misses into review",
+    "heroSubtitle": "Wrong answers from book and news quizzes are saved here for quick follow-up.",
+    "total": "Total",
+    "toReview": "To review",
+    "reviewed": "Reviewed",
+    "reviewedTimes": "Reviewed {count} times",
+    "filterAll": "All",
+    "filterToReview": "To review",
+    "filterReviewed": "Reviewed",
+    "emptyTitle": "No mistakes yet",
+    "emptySubtitle": "Missed quiz answers from Books and News will appear here automatically.",
+    "emptyFilterTitle": "Nothing in this filter",
+    "emptyFilterSubtitle": "Switch filters to see the rest of your notebook.",
+    "sourceBookQuiz": "Book quiz",
+    "sourceNewsQuiz": "News quiz",
+    "sourceFillBlank": "Fill in the Blank",
+    "sourceGrammarQuiz": "Grammar Quiz",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Your answer",
+    "correctAnswer": "Correct answer",
+    "explanation": "Explanation",
+    "markReviewed": "Mark reviewed",
+    "delete": "Delete",
+    "deleteTitle": "Delete mistake?",
+    "deleteMessage": "This removes the item from your notebook."
+  },
+  "vocabQuiz": {
+    "title": "Vocabulary Quiz",
+    "loading": "Building your quiz...",
+    "empty": "No words due for review!",
+    "tryAgain": "Try again",
+    "term": "TERM",
+    "definition": "DEFINITION",
+    "chooseCorrect": "Choose the correct answer",
+    "continueLabel": "Continue",
+    "finish": "Finish",
+    "correct": "Correct!",
+    "incorrect": "Not quite",
+    "exitTitle": "Exit quiz?",
+    "exitMessage": "Your progress so far is saved. Are you sure you want to exit?",
+    "chooseMode": "Choose a review mode",
+    "modeQuizTitle": "Multiple-choice quiz",
+    "modeQuizSubtitle": "Test meaning and term — auto-graded",
+    "modeFlashcardTitle": "Flashcards",
+    "modeFlashcardSubtitle": "Flip cards and rate yourself"
   }
 }
diff --git a/flutter-app/assets/i18n/ja.json b/flutter-app/assets/i18n/ja.json
index 31381435..24fd2c23 100644
--- a/flutter-app/assets/i18n/ja.json
+++ b/flutter-app/assets/i18n/ja.json
@@ -31,7 +31,8 @@
     "rename": "名前の変更",
     "play": "遊ぶ",
     "awesome": "素晴らしい！",
-    "create": "作成"
+    "create": "作成",
+    "refresh": "更新"
   },
   "auth": {
     "login": "ログイン",
@@ -208,7 +209,50 @@
     "pointsCalendar": "ポイントカレンダー",
     "setupCheckinReminder": "チェックインリマインダーを設定",
     "checkinReminder": "チェックインリマインダー",
-    "setTime": "時間を設定"
+    "setTime": "時間を設定",
+    "todayPlan": {
+      "title": "Today's Plan",
+      "subtitle": "A focused path through your next best tasks",
+      "footer": "Built from your reviews, courses, skills, and challenges.",
+      "viewAll": "View plan",
+      "heroTitle": "Your study route is ready",
+      "heroSubtitle": "Finish the next small task, then let LexiLingo guide you into the right practice.",
+      "completedSummary": "{completed}/{total} tasks complete",
+      "startNext": "Start next task",
+      "sequenceTitle": "Today's sequence",
+      "vocabularyTitle": "Review vocabulary",
+      "vocabularyCheckSubtitle": "Check if any words are due for review.",
+      "vocabularyDueSubtitle": "{count} words are waiting for review.",
+      "vocabularyDoneSubtitle": "You're caught up on vocabulary today.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Choose a course",
+      "courseFallbackSubtitle": "Pick a CEFR path and start your first lesson.",
+      "courseSubtitle": "Continue your {level} learning path.",
+      "courseMeta": "Course",
+      "courseProgress": "{percent}% done",
+      "skillFallbackTitle": "Practice speaking",
+      "skillFallbackSubtitle": "Warm up with a short pronunciation drill.",
+      "skillTitle": "Strengthen {skill}",
+      "skillSubtitle": "Current estimate: {level}.",
+      "skillMeta": "Skill",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Play a quick game",
+      "challengeFallbackSubtitle": "Earn XP with a short English challenge.",
+      "challengeMeta": "Challenge",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat with Lexi",
+      "lexiSubtitle": "Close the loop with a short AI conversation.",
+      "lexiMeta": "AI Tutor",
+      "reviewAction": "Review",
+      "checkAction": "Check",
+      "browseAction": "Browse",
+      "continueAction": "Continue",
+      "practiceAction": "Practice",
+      "playAction": "Play",
+      "startAction": "Start",
+      "doneAction": "Done",
+      "chatAction": "Chat"
+    }
   },
   "course": {
     "title": "コース",
@@ -357,7 +401,10 @@
     "playbackSpeedDescription": "テキスト読み上げオーディオの再生速度を調整する",
     "selectPlaybackSpeed": "再生速度の選択",
     "confidence": "信頼度: {percent}%",
-    "playError": "再生に失敗しました: {error}"
+    "playError": "再生に失敗しました: {error}",
+    "tapToRecord": "Tap to record",
+    "tapToStop": "Tap to stop",
+    "assessmentFailed": "Pronunciation assessment failed. Please try again."
   },
   "chat": {
     "placeholder": "メッセージを入力してください...",
@@ -619,7 +666,19 @@
     "earnTipFinishCourse": "コースを完了する",
     "earnTipStreakBonus": "デイリーストリークボーナス",
     "earnTipAchievements": "実績を解除する",
-    "earnTipChallenges": "ウィークリーチャレンジ"
+    "earnTipChallenges": "ウィークリーチャレンジ",
+    "dailyStreakRewardAvailable": "Daily Streak Reward!",
+    "dailyStreakRewardSubtitle": "You've kept your streak alive! Claim your daily reward now.",
+    "claimDailyRewardButton": "Claim Daily Reward",
+    "dailyRewardClaimed": "Daily Reward Claimed!",
+    "gemsReceived": "You received {gems} gems!",
+    "starterReward": {
+      "title": "Welcome gift!",
+      "description": "Use Gems to unlock special items in the shop.",
+      "action": "Awesome!",
+      "gemLabel": "Gem reward",
+      "confirmation": "{gems} Gems were added to your wallet."
+    }
   },
   "social": {
     "friends": "友達",
@@ -668,7 +727,29 @@
     "skipTour": "ツアーをスキップ",
     "activeUsers": "アクティブユーザー",
     "dailyLessons": "毎日のレッスン",
-    "globalCommunity": "グローバルコミュニティに参加しましょう"
+    "globalCommunity": "グローバルコミュニティに参加しましょう",
+    "personalizeTitle": "学習をカスタマイズ",
+    "goalQuestion": "あなたの目標は何ですか？",
+    "goalSubtitle": "選択内容に基づいて学習体験を調整します。",
+    "levelQuestion": "現在のレベルは？",
+    "levelSubtitle": "最初から適切な難易度のコンテンツを設定するために使います。",
+    "interestQuestion": "特に好きなトピックは？",
+    "interestSubtitle": "興味に合わせたレッスンを優先します。",
+    "continueBtn": "続ける",
+    "createPlan": "学習プランを作成",
+    "goalCareer": "キャリア",
+    "goalTravel": "旅行",
+    "goalExams": "試験",
+    "goalCulture": "文化",
+    "levelA1": "A1 - 初級",
+    "levelA2": "A2 - 初中級",
+    "levelB1": "B1 - 中級",
+    "levelB2": "B2 - 中上級",
+    "levelC1": "C1 - 上級",
+    "interestDailyLife": "日常生活と社会的な話題",
+    "interestTechnology": "テクノロジーとイノベーション",
+    "interestCulture": "文化とエンタメ",
+    "interestCareer": "キャリアアップと面接"
   },
   "preAuth": {
     "quickSetup": "クイックセットアップ",
@@ -725,7 +806,21 @@
     "readingSpeed": "読解速度",
     "retakeTest": "テストを再受験する",
     "yourLevelIs": "あなたのレベルは {level} です",
-    "testCompleted": "テスト完了"
+    "testCompleted": "テスト完了",
+    "questionCounter": "Question {current} of {total}",
+    "answeredCount": "{answered}/{total} answered",
+    "points": "{points} pts",
+    "previous": "Previous",
+    "next": "Next",
+    "submitTest": "Submit test",
+    "answerAllQuestions": "Answer every question before submitting.",
+    "resultSubtitle": "Your CEFR profile has been updated from this assessment.",
+    "score": "Score",
+    "correct": "Correct",
+    "rank": "Rank",
+    "loadFailed": "Could not load the test",
+    "noQuestions": "No questions available",
+    "noQuestionsSubtitle": "Try again in a moment."
   },
   "premium": {
     "title": "(Premium) Go Premium",
@@ -777,7 +872,10 @@
     "categoryPowerUps": "パワーアップ",
     "categoryBoosts": "ブースト",
     "categoryCosmetics": "化粧品",
-    "categorySpecial": "特別"
+    "categorySpecial": "特別",
+    "equipNow": "Equip now",
+    "avatarEquipped": "Avatar equipped successfully!",
+    "avatarEquipFailed": "Could not equip this avatar."
   },
   "leaderboard": {
     "title": "リーダーボード",
@@ -867,7 +965,9 @@
     "streakLabel": "ストリーク",
     "streakBonusLabel": "連続ボーナス: {multiplier}x",
     "playAgainButton": "もう一度プレイする",
-    "backToGamesButton": "ゲームに戻る"
+    "backToGamesButton": "ゲームに戻る",
+    "xpNotAwarded": "XP was not awarded. Your game result is preserved.",
+    "retryXp": "Retry XP award"
   },
   "spellingBee": {
     "wordProgress": "ワード {current}/{total}",
@@ -877,7 +977,15 @@
     "correctFeedback": "正しい！",
     "answerRevealLabel": "答えは次のとおりです。",
     "nextWordButton": "次の単語",
-    "seeResultsButton": "結果を見る"
+    "seeResultsButton": "結果を見る",
+    "audioError": "Could not play audio. Check your connection.",
+    "retryAudio": "Retry",
+    "listenButtonLabel": "Listen to the word",
+    "noPlaysLeft": "No plays remaining",
+    "abandonTitle": "Quit game?",
+    "abandonBody": "XP will be based on words answered correctly so far.",
+    "keepPlaying": "Keep playing",
+    "quit": "Quit"
   },
   "wordScramble": {
     "wordProgress": "ワード {current}/{total}",
@@ -1045,7 +1153,10 @@
     "unlockGoldenChest": "ゴールデンチェスト",
     "unlockGems": "50ジェム",
     "unlockXpBooster": "2倍XPブースター",
-    "continueJourney": "学習を続ける"
+    "continueJourney": "学習を続ける",
+    "loadFailed": "Unable to load this game. Please try again.",
+    "emptyGame": "This game has no playable content right now.",
+    "retryLoad": "Try again"
   },
   "learning": {
     "checkAnswer": "答えを確認する",
@@ -1072,7 +1183,8 @@
     "backToBook": "本に戻る",
     "readerSettings": "リーダーの設定",
     "pageProgress": "ページ {current}/{total}",
-    "searchPlaceholder": "タイトルまたは著者で検索..."
+    "searchPlaceholder": "タイトルまたは著者で検索...",
+    "savedBooks": "保存した本"
   },
   "news": {
     "title": "英語ニュース",
@@ -1146,11 +1258,165 @@
     "topicScienceSubtitle": "概念と発見",
     "topicTechnology": "テクノロジー",
     "topicTechnologySubtitle": "ソフトウェアとデジタル時代",
-    "noDefinitionYet": "定義がまだありません"
+    "noDefinitionYet": "定義がまだありません",
+    "translationLabel": "翻訳",
+    "tabWords": "Words",
+    "tabTopics": "Topic Flashcards",
+    "startLearning": "Start",
+    "audioQuestionHint": "Listen and guess the word"
   },
   "legal": {
     "privacy_title": "プライバシーポリシー",
     "terms_title": "利用規約",
     "last_updated": "最終更新: {date}"
+  },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Manage cache and pending sync",
+    "entrySubtitle": "Review offline data, cache, and queued updates",
+    "onlineTitle": "You are online",
+    "onlineSubtitle": "Fresh content and queued changes can sync normally.",
+    "offlineTitle": "You are offline",
+    "offlineSubtitle": "Cached content can still open; new changes may wait in the queue.",
+    "cacheTitle": "API cache",
+    "cacheSubtitle": "Cached content used for faster loading and offline fallback.",
+    "totalEntries": "Total entries",
+    "noCache": "No cached API responses yet.",
+    "clearExpired": "Clear expired",
+    "clearAll": "Clear all",
+    "clearAllTitle": "Clear all cached API data?",
+    "clearAllMessage": "This removes cached public content. Your account, saved progress, and pending sync queue are not deleted.",
+    "clearAllConfirm": "Clear cache",
+    "expiredCleared": "Cleared {count} expired cache entries.",
+    "allCacheCleared": "All API cache entries were cleared.",
+    "queueTitle": "Sync queue",
+    "queueSubtitle": "Pending offline actions waiting to be sent.",
+    "totalQueued": "Total queued",
+    "readyQueued": "Ready now",
+    "scheduledQueued": "Scheduled retry",
+    "retryingQueued": "Retrying",
+    "queueHint": "Queued work is processed automatically when the app is online and the account is active.",
+    "queueUnavailable": "Persistent sync queue is not available on this platform.",
+    "noUserScope": "Sign in to see account-scoped sync queue status.",
+    "loadFailed": "Could not load offline status",
+    "cacheTypes": {
+      "news": "News",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Books",
+      "dictionary": "Dictionary",
+      "game": "Games",
+      "flashcard": "Flashcards"
+    }
+  },
+  "practiceLab": {
+    "title": "Practice Lab",
+    "shortTitle": "Practice",
+    "heroTitle": "Train by skill",
+    "heroSubtitle": "Pick the exact skill you want to sharpen, or follow the focus areas from your CEFR profile.",
+    "currentLevel": "Current level",
+    "recommended": "Focus skills",
+    "recommendedTitle": "Recommended practice",
+    "recommendedSubtitle": "Based on your weakest proficiency scores.",
+    "fallbackSubtitle": "Practice a balanced mix while LexiLingo learns your strengths.",
+    "allSkillsTitle": "All skill labs",
+    "allSkillsSubtitle": "Jump into a focused practice mode using existing lessons, games, audio, and Lexi.",
+    "focus": "Focus",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Unlock advanced Lexi-guided writing practice with Premium.",
+    "unlockPremium": "Unlock Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Vocabulary",
+        "subtitle": "Review due words and strengthen recall.",
+        "action": "Review words",
+        "estimate": "5-8 min"
+      },
+      "speaking": {
+        "title": "Speaking",
+        "subtitle": "Practice pronunciation and spoken responses.",
+        "action": "Speak now",
+        "estimate": "6-10 min"
+      },
+      "listening": {
+        "title": "Listening",
+        "subtitle": "Train your ear with graded podcast content.",
+        "action": "Listen",
+        "estimate": "8-12 min"
+      },
+      "reading": {
+        "title": "Reading",
+        "subtitle": "Read CEFR-graded news and check comprehension.",
+        "action": "Read",
+        "estimate": "7-10 min"
+      },
+      "grammar": {
+        "title": "Grammar",
+        "subtitle": "Use games and quizzes to reinforce structure.",
+        "action": "Practice",
+        "estimate": "5-9 min"
+      },
+      "writing": {
+        "title": "Writing",
+        "subtitle": "Draft sentences with Lexi and refine your output.",
+        "action": "Open Lexi",
+        "estimate": "6-10 min"
+      },
+      "mistakes": {
+        "title": "Mistake Notebook",
+        "subtitle": "Review questions you missed in reading quizzes.",
+        "action": "Review mistakes",
+        "estimate": "4-8 min"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Mistake Notebook",
+    "heroTitle": "Turn misses into review",
+    "heroSubtitle": "Wrong answers from book and news quizzes are saved here for quick follow-up.",
+    "total": "Total",
+    "toReview": "To review",
+    "reviewed": "Reviewed",
+    "reviewedTimes": "Reviewed {count} times",
+    "filterAll": "All",
+    "filterToReview": "To review",
+    "filterReviewed": "Reviewed",
+    "emptyTitle": "No mistakes yet",
+    "emptySubtitle": "Missed quiz answers from Books and News will appear here automatically.",
+    "emptyFilterTitle": "Nothing in this filter",
+    "emptyFilterSubtitle": "Switch filters to see the rest of your notebook.",
+    "sourceBookQuiz": "Book quiz",
+    "sourceNewsQuiz": "News quiz",
+    "sourceFillBlank": "Fill in the Blank",
+    "sourceGrammarQuiz": "Grammar Quiz",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Your answer",
+    "correctAnswer": "Correct answer",
+    "explanation": "Explanation",
+    "markReviewed": "Mark reviewed",
+    "delete": "Delete",
+    "deleteTitle": "Delete mistake?",
+    "deleteMessage": "This removes the item from your notebook."
+  },
+  "vocabQuiz": {
+    "title": "Vocabulary Quiz",
+    "loading": "Building your quiz...",
+    "empty": "No words due for review!",
+    "tryAgain": "Try again",
+    "term": "TERM",
+    "definition": "DEFINITION",
+    "chooseCorrect": "Choose the correct answer",
+    "continueLabel": "Continue",
+    "finish": "Finish",
+    "correct": "Correct!",
+    "incorrect": "Not quite",
+    "exitTitle": "Exit quiz?",
+    "exitMessage": "Your progress so far is saved. Are you sure you want to exit?",
+    "chooseMode": "Choose a review mode",
+    "modeQuizTitle": "Multiple-choice quiz",
+    "modeQuizSubtitle": "Test meaning and term — auto-graded",
+    "modeFlashcardTitle": "Flashcards",
+    "modeFlashcardSubtitle": "Flip cards and rate yourself"
   }
 }
diff --git a/flutter-app/assets/i18n/ko.json b/flutter-app/assets/i18n/ko.json
index c2f64b9c..e0600d56 100644
--- a/flutter-app/assets/i18n/ko.json
+++ b/flutter-app/assets/i18n/ko.json
@@ -31,7 +31,8 @@
     "rename": "이름 바꾸기",
     "play": "놀다",
     "awesome": "엄청난!",
-    "create": "만들기"
+    "create": "만들기",
+    "refresh": "새로고침"
   },
   "auth": {
     "login": "로그인",
@@ -208,7 +209,50 @@
     "pointsCalendar": "포인트 캘린더",
     "setupCheckinReminder": "체크인 알림 설정",
     "checkinReminder": "체크인 알림",
-    "setTime": "시간 설정"
+    "setTime": "시간 설정",
+    "todayPlan": {
+      "title": "Today's Plan",
+      "subtitle": "A focused path through your next best tasks",
+      "footer": "Built from your reviews, courses, skills, and challenges.",
+      "viewAll": "View plan",
+      "heroTitle": "Your study route is ready",
+      "heroSubtitle": "Finish the next small task, then let LexiLingo guide you into the right practice.",
+      "completedSummary": "{completed}/{total} tasks complete",
+      "startNext": "Start next task",
+      "sequenceTitle": "Today's sequence",
+      "vocabularyTitle": "Review vocabulary",
+      "vocabularyCheckSubtitle": "Check if any words are due for review.",
+      "vocabularyDueSubtitle": "{count} words are waiting for review.",
+      "vocabularyDoneSubtitle": "You're caught up on vocabulary today.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Choose a course",
+      "courseFallbackSubtitle": "Pick a CEFR path and start your first lesson.",
+      "courseSubtitle": "Continue your {level} learning path.",
+      "courseMeta": "Course",
+      "courseProgress": "{percent}% done",
+      "skillFallbackTitle": "Practice speaking",
+      "skillFallbackSubtitle": "Warm up with a short pronunciation drill.",
+      "skillTitle": "Strengthen {skill}",
+      "skillSubtitle": "Current estimate: {level}.",
+      "skillMeta": "Skill",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Play a quick game",
+      "challengeFallbackSubtitle": "Earn XP with a short English challenge.",
+      "challengeMeta": "Challenge",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat with Lexi",
+      "lexiSubtitle": "Close the loop with a short AI conversation.",
+      "lexiMeta": "AI Tutor",
+      "reviewAction": "Review",
+      "checkAction": "Check",
+      "browseAction": "Browse",
+      "continueAction": "Continue",
+      "practiceAction": "Practice",
+      "playAction": "Play",
+      "startAction": "Start",
+      "doneAction": "Done",
+      "chatAction": "Chat"
+    }
   },
   "course": {
     "title": "행동",
@@ -357,7 +401,10 @@
     "playbackSpeedDescription": "텍스트 음성 변환 오디오 재생 속도 조정",
     "selectPlaybackSpeed": "재생 속도 선택",
     "confidence": "신뢰도: {percent}%",
-    "playError": "재생 실패: {error}"
+    "playError": "재생 실패: {error}",
+    "tapToRecord": "Tap to record",
+    "tapToStop": "Tap to stop",
+    "assessmentFailed": "Pronunciation assessment failed. Please try again."
   },
   "chat": {
     "placeholder": "메시지를 입력하세요...",
@@ -619,7 +666,19 @@
     "earnTipFinishCourse": "강좌 완료하기",
     "earnTipStreakBonus": "일일 연속 보너스",
     "earnTipAchievements": "도전과제 달성하기",
-    "earnTipChallenges": "주간 챌린지"
+    "earnTipChallenges": "주간 챌린지",
+    "dailyStreakRewardAvailable": "Daily Streak Reward!",
+    "dailyStreakRewardSubtitle": "You've kept your streak alive! Claim your daily reward now.",
+    "claimDailyRewardButton": "Claim Daily Reward",
+    "dailyRewardClaimed": "Daily Reward Claimed!",
+    "gemsReceived": "You received {gems} gems!",
+    "starterReward": {
+      "title": "Welcome gift!",
+      "description": "Use Gems to unlock special items in the shop.",
+      "action": "Awesome!",
+      "gemLabel": "Gem reward",
+      "confirmation": "{gems} Gems were added to your wallet."
+    }
   },
   "social": {
     "friends": "친구",
@@ -668,7 +727,29 @@
     "skipTour": "둘러보기 건너뛰기",
     "activeUsers": "활성 사용자",
     "dailyLessons": "일일 레슨",
-    "globalCommunity": "글로벌 커뮤니티에 가입하세요"
+    "globalCommunity": "글로벌 커뮤니티에 가입하세요",
+    "personalizeTitle": "학습 맞춤 설정",
+    "goalQuestion": "목표가 무엇인가요?",
+    "goalSubtitle": "선택한 목표에 맞춰 학습 경험을 조정할게요.",
+    "levelQuestion": "현재 레벨은 무엇인가요?",
+    "levelSubtitle": "처음부터 적절한 난이도의 콘텐츠를 설정하는 데 도움이 됩니다.",
+    "interestQuestion": "가장 좋아하는 주제는 무엇인가요?",
+    "interestSubtitle": "관심사에 맞는 레슨을 우선으로 추천할게요.",
+    "continueBtn": "계속",
+    "createPlan": "내 학습 계획 만들기",
+    "goalCareer": "커리어",
+    "goalTravel": "여행",
+    "goalExams": "시험",
+    "goalCulture": "문화",
+    "levelA1": "A1 - 입문",
+    "levelA2": "A2 - 초급",
+    "levelB1": "B1 - 중급",
+    "levelB2": "B2 - 중상급",
+    "levelC1": "C1 - 고급",
+    "interestDailyLife": "일상생활 및 사회 주제",
+    "interestTechnology": "기술과 혁신",
+    "interestCulture": "문화와 엔터테인먼트",
+    "interestCareer": "커리어 성장과 면접"
   },
   "preAuth": {
     "quickSetup": "빠른 설정",
@@ -725,7 +806,21 @@
     "readingSpeed": "읽기 속도",
     "retakeTest": "시험 다시 보기",
     "yourLevelIs": "당신의 레벨은 {level}입니다",
-    "testCompleted": "시험 완료"
+    "testCompleted": "시험 완료",
+    "questionCounter": "Question {current} of {total}",
+    "answeredCount": "{answered}/{total} answered",
+    "points": "{points} pts",
+    "previous": "Previous",
+    "next": "Next",
+    "submitTest": "Submit test",
+    "answerAllQuestions": "Answer every question before submitting.",
+    "resultSubtitle": "Your CEFR profile has been updated from this assessment.",
+    "score": "Score",
+    "correct": "Correct",
+    "rank": "Rank",
+    "loadFailed": "Could not load the test",
+    "noQuestions": "No questions available",
+    "noQuestionsSubtitle": "Try again in a moment."
   },
   "premium": {
     "title": "(Premium) Go Premium",
@@ -777,7 +872,10 @@
     "categoryPowerUps": "파워업",
     "categoryBoosts": "부스트",
     "categoryCosmetics": "화장품",
-    "categorySpecial": "특별한"
+    "categorySpecial": "특별한",
+    "equipNow": "Equip now",
+    "avatarEquipped": "Avatar equipped successfully!",
+    "avatarEquipFailed": "Could not equip this avatar."
   },
   "leaderboard": {
     "title": "리더보드",
@@ -867,7 +965,9 @@
     "streakLabel": "줄",
     "streakBonusLabel": "연속 보너스: {multiplier}x",
     "playAgainButton": "다시 플레이",
-    "backToGamesButton": "게임으로 돌아가기"
+    "backToGamesButton": "게임으로 돌아가기",
+    "xpNotAwarded": "XP was not awarded. Your game result is preserved.",
+    "retryXp": "Retry XP award"
   },
   "spellingBee": {
     "wordProgress": "단어 {current}/{total}",
@@ -877,7 +977,15 @@
     "correctFeedback": "옳은!",
     "answerRevealLabel": "대답은 다음과 같습니다.",
     "nextWordButton": "다음 단어",
-    "seeResultsButton": "결과 보기"
+    "seeResultsButton": "결과 보기",
+    "audioError": "Could not play audio. Check your connection.",
+    "retryAudio": "Retry",
+    "listenButtonLabel": "Listen to the word",
+    "noPlaysLeft": "No plays remaining",
+    "abandonTitle": "Quit game?",
+    "abandonBody": "XP will be based on words answered correctly so far.",
+    "keepPlaying": "Keep playing",
+    "quit": "Quit"
   },
   "wordScramble": {
     "wordProgress": "{total}의 단어 {current}",
@@ -1045,7 +1153,10 @@
     "unlockGoldenChest": "황금 상자",
     "unlockGems": "보석 50개",
     "unlockXpBooster": "2배 XP 부스터",
-    "continueJourney": "학습 계속하기"
+    "continueJourney": "학습 계속하기",
+    "loadFailed": "Unable to load this game. Please try again.",
+    "emptyGame": "This game has no playable content right now.",
+    "retryLoad": "Try again"
   },
   "learning": {
     "checkAnswer": "답변 확인",
@@ -1072,7 +1183,8 @@
     "backToBook": "예약으로 돌아가기",
     "readerSettings": "리더 설정",
     "pageProgress": "{total} 중 {current} 페이지",
-    "searchPlaceholder": "제목 또는 저자로 검색..."
+    "searchPlaceholder": "제목 또는 저자로 검색...",
+    "savedBooks": "저장한 책"
   },
   "news": {
     "title": "영어 뉴스",
@@ -1146,11 +1258,165 @@
     "topicScienceSubtitle": "개념 & 발견",
     "topicTechnology": "기술",
     "topicTechnologySubtitle": "소프트웨어 & 디지털 시대",
-    "noDefinitionYet": "아직 정의 없음"
+    "noDefinitionYet": "아직 정의 없음",
+    "translationLabel": "번역",
+    "tabWords": "Words",
+    "tabTopics": "Topic Flashcards",
+    "startLearning": "Start",
+    "audioQuestionHint": "Listen and guess the word"
   },
   "legal": {
     "privacy_title": "개인정보 처리방침",
     "terms_title": "이용약관",
     "last_updated": "최종 업데이트: {date}"
+  },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Manage cache and pending sync",
+    "entrySubtitle": "Review offline data, cache, and queued updates",
+    "onlineTitle": "You are online",
+    "onlineSubtitle": "Fresh content and queued changes can sync normally.",
+    "offlineTitle": "You are offline",
+    "offlineSubtitle": "Cached content can still open; new changes may wait in the queue.",
+    "cacheTitle": "API cache",
+    "cacheSubtitle": "Cached content used for faster loading and offline fallback.",
+    "totalEntries": "Total entries",
+    "noCache": "No cached API responses yet.",
+    "clearExpired": "Clear expired",
+    "clearAll": "Clear all",
+    "clearAllTitle": "Clear all cached API data?",
+    "clearAllMessage": "This removes cached public content. Your account, saved progress, and pending sync queue are not deleted.",
+    "clearAllConfirm": "Clear cache",
+    "expiredCleared": "Cleared {count} expired cache entries.",
+    "allCacheCleared": "All API cache entries were cleared.",
+    "queueTitle": "Sync queue",
+    "queueSubtitle": "Pending offline actions waiting to be sent.",
+    "totalQueued": "Total queued",
+    "readyQueued": "Ready now",
+    "scheduledQueued": "Scheduled retry",
+    "retryingQueued": "Retrying",
+    "queueHint": "Queued work is processed automatically when the app is online and the account is active.",
+    "queueUnavailable": "Persistent sync queue is not available on this platform.",
+    "noUserScope": "Sign in to see account-scoped sync queue status.",
+    "loadFailed": "Could not load offline status",
+    "cacheTypes": {
+      "news": "News",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Books",
+      "dictionary": "Dictionary",
+      "game": "Games",
+      "flashcard": "Flashcards"
+    }
+  },
+  "practiceLab": {
+    "title": "Practice Lab",
+    "shortTitle": "Practice",
+    "heroTitle": "Train by skill",
+    "heroSubtitle": "Pick the exact skill you want to sharpen, or follow the focus areas from your CEFR profile.",
+    "currentLevel": "Current level",
+    "recommended": "Focus skills",
+    "recommendedTitle": "Recommended practice",
+    "recommendedSubtitle": "Based on your weakest proficiency scores.",
+    "fallbackSubtitle": "Practice a balanced mix while LexiLingo learns your strengths.",
+    "allSkillsTitle": "All skill labs",
+    "allSkillsSubtitle": "Jump into a focused practice mode using existing lessons, games, audio, and Lexi.",
+    "focus": "Focus",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Unlock advanced Lexi-guided writing practice with Premium.",
+    "unlockPremium": "Unlock Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Vocabulary",
+        "subtitle": "Review due words and strengthen recall.",
+        "action": "Review words",
+        "estimate": "5-8 min"
+      },
+      "speaking": {
+        "title": "Speaking",
+        "subtitle": "Practice pronunciation and spoken responses.",
+        "action": "Speak now",
+        "estimate": "6-10 min"
+      },
+      "listening": {
+        "title": "Listening",
+        "subtitle": "Train your ear with graded podcast content.",
+        "action": "Listen",
+        "estimate": "8-12 min"
+      },
+      "reading": {
+        "title": "Reading",
+        "subtitle": "Read CEFR-graded news and check comprehension.",
+        "action": "Read",
+        "estimate": "7-10 min"
+      },
+      "grammar": {
+        "title": "Grammar",
+        "subtitle": "Use games and quizzes to reinforce structure.",
+        "action": "Practice",
+        "estimate": "5-9 min"
+      },
+      "writing": {
+        "title": "Writing",
+        "subtitle": "Draft sentences with Lexi and refine your output.",
+        "action": "Open Lexi",
+        "estimate": "6-10 min"
+      },
+      "mistakes": {
+        "title": "Mistake Notebook",
+        "subtitle": "Review questions you missed in reading quizzes.",
+        "action": "Review mistakes",
+        "estimate": "4-8 min"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Mistake Notebook",
+    "heroTitle": "Turn misses into review",
+    "heroSubtitle": "Wrong answers from book and news quizzes are saved here for quick follow-up.",
+    "total": "Total",
+    "toReview": "To review",
+    "reviewed": "Reviewed",
+    "reviewedTimes": "Reviewed {count} times",
+    "filterAll": "All",
+    "filterToReview": "To review",
+    "filterReviewed": "Reviewed",
+    "emptyTitle": "No mistakes yet",
+    "emptySubtitle": "Missed quiz answers from Books and News will appear here automatically.",
+    "emptyFilterTitle": "Nothing in this filter",
+    "emptyFilterSubtitle": "Switch filters to see the rest of your notebook.",
+    "sourceBookQuiz": "Book quiz",
+    "sourceNewsQuiz": "News quiz",
+    "sourceFillBlank": "Fill in the Blank",
+    "sourceGrammarQuiz": "Grammar Quiz",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Your answer",
+    "correctAnswer": "Correct answer",
+    "explanation": "Explanation",
+    "markReviewed": "Mark reviewed",
+    "delete": "Delete",
+    "deleteTitle": "Delete mistake?",
+    "deleteMessage": "This removes the item from your notebook."
+  },
+  "vocabQuiz": {
+    "title": "Vocabulary Quiz",
+    "loading": "Building your quiz...",
+    "empty": "No words due for review!",
+    "tryAgain": "Try again",
+    "term": "TERM",
+    "definition": "DEFINITION",
+    "chooseCorrect": "Choose the correct answer",
+    "continueLabel": "Continue",
+    "finish": "Finish",
+    "correct": "Correct!",
+    "incorrect": "Not quite",
+    "exitTitle": "Exit quiz?",
+    "exitMessage": "Your progress so far is saved. Are you sure you want to exit?",
+    "chooseMode": "Choose a review mode",
+    "modeQuizTitle": "Multiple-choice quiz",
+    "modeQuizSubtitle": "Test meaning and term — auto-graded",
+    "modeFlashcardTitle": "Flashcards",
+    "modeFlashcardSubtitle": "Flip cards and rate yourself"
   }
 }
diff --git a/flutter-app/assets/i18n/vi.json b/flutter-app/assets/i18n/vi.json
index e72014d8..c0346a90 100644
--- a/flutter-app/assets/i18n/vi.json
+++ b/flutter-app/assets/i18n/vi.json
@@ -31,7 +31,8 @@
     "rename": "Đổi tên",
     "play": "Chơi",
     "awesome": "Tuyệt vời!",
-    "create": "Tạo"
+    "create": "Tạo",
+    "refresh": "Làm mới"
   },
   "auth": {
     "login": "Đăng nhập",
@@ -170,6 +171,49 @@
     "todayProgress": "Tiến độ hôm nay",
     "weeklyStats": "Thống kê tuần",
     "recommendations": "Gợi ý cho bạn",
+    "todayPlan": {
+      "title": "Kế hoạch hôm nay",
+      "subtitle": "Lộ trình gọn cho các nhiệm vụ nên học tiếp",
+      "footer": "Được ghép từ ôn tập, khóa học, kỹ năng và thử thách của bạn.",
+      "viewAll": "Xem kế hoạch",
+      "heroTitle": "Lộ trình học của bạn đã sẵn sàng",
+      "heroSubtitle": "Hoàn thành nhiệm vụ nhỏ tiếp theo, rồi để LexiLingo dẫn bạn vào phần luyện tập phù hợp.",
+      "completedSummary": "Hoàn thành {completed}/{total} nhiệm vụ",
+      "startNext": "Bắt đầu nhiệm vụ tiếp theo",
+      "sequenceTitle": "Thứ tự học hôm nay",
+      "vocabularyTitle": "Ôn từ vựng",
+      "vocabularyCheckSubtitle": "Kiểm tra xem có từ nào đến hạn ôn không.",
+      "vocabularyDueSubtitle": "{count} từ đang chờ ôn tập.",
+      "vocabularyDoneSubtitle": "Hôm nay bạn đã ôn xong từ vựng.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Chọn một khóa học",
+      "courseFallbackSubtitle": "Chọn lộ trình CEFR và bắt đầu bài đầu tiên.",
+      "courseSubtitle": "Tiếp tục lộ trình {level} của bạn.",
+      "courseMeta": "Khóa học",
+      "courseProgress": "Đã học {percent}%",
+      "skillFallbackTitle": "Luyện nói",
+      "skillFallbackSubtitle": "Khởi động bằng một bài phát âm ngắn.",
+      "skillTitle": "Củng cố {skill}",
+      "skillSubtitle": "Ước tính hiện tại: {level}.",
+      "skillMeta": "Kỹ năng",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Chơi nhanh một game",
+      "challengeFallbackSubtitle": "Kiếm XP bằng một thử thách tiếng Anh ngắn.",
+      "challengeMeta": "Thử thách",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat với Lexi",
+      "lexiSubtitle": "Kết thúc vòng học bằng một đoạn hội thoại AI ngắn.",
+      "lexiMeta": "Gia sư AI",
+      "reviewAction": "Ôn tập",
+      "checkAction": "Kiểm tra",
+      "browseAction": "Duyệt",
+      "continueAction": "Tiếp tục",
+      "practiceAction": "Luyện tập",
+      "playAction": "Chơi",
+      "startAction": "Bắt đầu",
+      "doneAction": "Xong",
+      "chatAction": "Chat"
+    },
     "loadingChallenges": "Đang tải thử thách...",
     "dailyChallenges": "Thử thách hàng ngày",
     "challengesCompleted": "{completed}/{total} đã hoàn thành",
@@ -756,13 +800,156 @@
     "adverb": "Trạng từ",
     "pronunciation": "Phát âm"
   },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Quản lý cache và đồng bộ chờ",
+    "entrySubtitle": "Xem dữ liệu offline, cache và thay đổi đang chờ gửi",
+    "onlineTitle": "Bạn đang online",
+    "onlineSubtitle": "Nội dung mới và thay đổi đang chờ có thể đồng bộ bình thường.",
+    "offlineTitle": "Bạn đang offline",
+    "offlineSubtitle": "Nội dung đã cache vẫn có thể mở; thay đổi mới sẽ chờ trong hàng đợi.",
+    "cacheTitle": "Cache API",
+    "cacheSubtitle": "Nội dung đã lưu giúp tải nhanh hơn và dùng khi mất mạng.",
+    "totalEntries": "Tổng mục",
+    "noCache": "Chưa có phản hồi API nào được cache.",
+    "clearExpired": "Xóa hết hạn",
+    "clearAll": "Xóa tất cả",
+    "clearAllTitle": "Xóa toàn bộ cache API?",
+    "clearAllMessage": "Thao tác này xóa nội dung công khai đã cache. Tài khoản, tiến độ đã lưu và hàng đợi đồng bộ không bị xóa.",
+    "clearAllConfirm": "Xóa cache",
+    "expiredCleared": "Đã xóa {count} mục cache hết hạn.",
+    "allCacheCleared": "Đã xóa toàn bộ cache API.",
+    "queueTitle": "Hàng đợi đồng bộ",
+    "queueSubtitle": "Các thao tác offline đang chờ gửi.",
+    "totalQueued": "Tổng đang chờ",
+    "readyQueued": "Sẵn sàng gửi",
+    "scheduledQueued": "Chờ thử lại",
+    "retryingQueued": "Đang thử lại",
+    "queueHint": "Hàng đợi sẽ tự xử lý khi app online và tài khoản đang hoạt động.",
+    "queueUnavailable": "Hàng đợi đồng bộ bền vững chưa khả dụng trên nền tảng này.",
+    "noUserScope": "Đăng nhập để xem trạng thái đồng bộ theo tài khoản.",
+    "loadFailed": "Không tải được trạng thái offline",
+    "cacheTypes": {
+      "news": "Tin tức",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Sách",
+      "dictionary": "Từ điển",
+      "game": "Game",
+      "flashcard": "Flashcard"
+    }
+  },
+  "practiceLab": {
+    "title": "Phòng luyện tập",
+    "shortTitle": "Luyện tập",
+    "heroTitle": "Luyện theo kỹ năng",
+    "heroSubtitle": "Chọn đúng kỹ năng muốn cải thiện, hoặc theo các vùng cần tập trung từ hồ sơ CEFR của bạn.",
+    "currentLevel": "Trình độ hiện tại",
+    "recommended": "Kỹ năng trọng tâm",
+    "recommendedTitle": "Gợi ý luyện tập",
+    "recommendedSubtitle": "Dựa trên các điểm kỹ năng yếu nhất của bạn.",
+    "fallbackSubtitle": "Luyện cân bằng trong lúc LexiLingo học thêm về điểm mạnh của bạn.",
+    "allSkillsTitle": "Tất cả phòng luyện",
+    "allSkillsSubtitle": "Vào nhanh chế độ luyện tập bằng bài học, game, audio và Lexi hiện có.",
+    "focus": "Trọng tâm",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Mở khóa luyện viết nâng cao với Lexi bằng Premium.",
+    "unlockPremium": "Mở khóa Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Từ vựng",
+        "subtitle": "Ôn các từ đến hạn và tăng khả năng ghi nhớ.",
+        "action": "Ôn từ",
+        "estimate": "5-8 phút"
+      },
+      "speaking": {
+        "title": "Nói",
+        "subtitle": "Luyện phát âm và phản xạ nói.",
+        "action": "Nói ngay",
+        "estimate": "6-10 phút"
+      },
+      "listening": {
+        "title": "Nghe",
+        "subtitle": "Luyện tai nghe với podcast theo trình độ.",
+        "action": "Nghe",
+        "estimate": "8-12 phút"
+      },
+      "reading": {
+        "title": "Đọc",
+        "subtitle": "Đọc tin tức theo CEFR và kiểm tra hiểu bài.",
+        "action": "Đọc",
+        "estimate": "7-10 phút"
+      },
+      "grammar": {
+        "title": "Ngữ pháp",
+        "subtitle": "Dùng game và quiz để củng cố cấu trúc câu.",
+        "action": "Luyện",
+        "estimate": "5-9 phút"
+      },
+      "writing": {
+        "title": "Viết",
+        "subtitle": "Viết câu với Lexi và cải thiện cách diễn đạt.",
+        "action": "Mở Lexi",
+        "estimate": "6-10 phút"
+      },
+      "mistakes": {
+        "title": "Sổ lỗi sai",
+        "subtitle": "Ôn lại các câu bạn làm sai trong quiz đọc.",
+        "action": "Ôn lỗi sai",
+        "estimate": "4-8 phút"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Sổ lỗi sai",
+    "heroTitle": "Biến lỗi sai thành bài ôn",
+    "heroSubtitle": "Đáp án sai từ quiz sách và tin tức sẽ được lưu ở đây để bạn ôn nhanh.",
+    "total": "Tổng",
+    "toReview": "Cần ôn",
+    "reviewed": "Đã ôn",
+    "reviewedTimes": "Đã ôn {count} lần",
+    "filterAll": "Tất cả",
+    "filterToReview": "Cần ôn",
+    "filterReviewed": "Đã ôn",
+    "emptyTitle": "Chưa có lỗi sai",
+    "emptySubtitle": "Các câu sai từ Books và News sẽ tự xuất hiện tại đây.",
+    "emptyFilterTitle": "Không có mục trong bộ lọc này",
+    "emptyFilterSubtitle": "Đổi bộ lọc để xem phần còn lại của sổ lỗi sai.",
+    "sourceBookQuiz": "Quiz sách",
+    "sourceNewsQuiz": "Quiz tin tức",
+    "sourceFillBlank": "Điền vào chỗ trống",
+    "sourceGrammarQuiz": "Quiz ngữ pháp",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Bạn chọn",
+    "correctAnswer": "Đáp án đúng",
+    "explanation": "Giải thích",
+    "markReviewed": "Đánh dấu đã ôn",
+    "delete": "Xóa",
+    "deleteTitle": "Xóa lỗi sai?",
+    "deleteMessage": "Mục này sẽ bị xóa khỏi sổ lỗi sai."
+  },
   "assessment": {
     "placementTest": "Bài kiểm tra trình độ",
     "cefrLevel": "Trình độ CEFR",
     "readingSpeed": "Tốc độ đọc",
     "retakeTest": "Làm lại bài kiểm tra",
     "yourLevelIs": "Trình độ của bạn là {level}",
-    "testCompleted": "Đã hoàn thành kiểm tra"
+    "testCompleted": "Đã hoàn thành kiểm tra",
+    "questionCounter": "Câu {current}/{total}",
+    "answeredCount": "Đã trả lời {answered}/{total}",
+    "points": "{points} điểm",
+    "previous": "Trước",
+    "next": "Tiếp",
+    "submitTest": "Nộp bài",
+    "answerAllQuestions": "Hãy trả lời đủ mọi câu trước khi nộp.",
+    "resultSubtitle": "Hồ sơ CEFR của bạn đã được cập nhật từ bài kiểm tra này.",
+    "score": "Điểm",
+    "correct": "Đúng",
+    "rank": "Hạng",
+    "loadFailed": "Không tải được bài kiểm tra",
+    "noQuestions": "Chưa có câu hỏi",
+    "noQuestionsSubtitle": "Thử lại sau ít phút."
   },
   "premium": {
     "title": "Nâng cấp Premium",
@@ -1125,7 +1312,8 @@
     "backToBook": "Quay lại sách",
     "readerSettings": "Cài đặt đọc",
     "pageProgress": "Trang {current} / {total}",
-    "searchPlaceholder": "Tìm sách theo tên hoặc tác giả..."
+    "searchPlaceholder": "Tìm sách theo tên hoặc tác giả...",
+    "savedBooks": "Sách đã lưu"
   },
   "news": {
     "title": "Tin tức tiếng Anh",
@@ -1203,11 +1391,32 @@
     "topicScienceSubtitle": "Khái niệm & Khám phá",
     "topicTechnology": "Công nghệ",
     "topicTechnologySubtitle": "Phần mềm & Kỷ nguyên số",
-    "noDefinitionYet": "Chưa có định nghĩa"
+    "noDefinitionYet": "Chưa có định nghĩa",
+    "vietnameseLabel": "Tiếng Việt"
   },
   "legal": {
     "privacy_title": "Chính sách bảo mật",
     "terms_title": "Điều khoản sử dụng",
     "last_updated": "Cập nhật lần cuối: {date}"
+  },
+  "vocabQuiz": {
+    "title": "Quiz từ vựng",
+    "loading": "Đang tạo bài quiz...",
+    "empty": "Không có từ nào đến hạn ôn!",
+    "tryAgain": "Thử lại",
+    "term": "THUẬT NGỮ",
+    "definition": "ĐỊNH NGHĨA",
+    "chooseCorrect": "Chọn đáp án đúng",
+    "continueLabel": "Tiếp tục",
+    "finish": "Hoàn thành",
+    "correct": "Chính xác!",
+    "incorrect": "Chưa đúng",
+    "exitTitle": "Thoát quiz?",
+    "exitMessage": "Tiến độ của bạn đã được lưu. Bạn có chắc muốn thoát?",
+    "chooseMode": "Chọn chế độ ôn tập",
+    "modeQuizTitle": "Quiz trắc nghiệm",
+    "modeQuizSubtitle": "Kiểm tra nghĩa và thuật ngữ — tự chấm điểm",
+    "modeFlashcardTitle": "Thẻ ghi nhớ",
+    "modeFlashcardSubtitle": "Lật thẻ và tự đánh giá"
   }
 }
diff --git a/flutter-app/assets/i18n/zh.json b/flutter-app/assets/i18n/zh.json
index 264eb0a9..48051d10 100644
--- a/flutter-app/assets/i18n/zh.json
+++ b/flutter-app/assets/i18n/zh.json
@@ -31,7 +31,8 @@
     "rename": "重命名",
     "play": "玩",
     "awesome": "惊人的！",
-    "create": "创建"
+    "create": "创建",
+    "refresh": "刷新"
   },
   "auth": {
     "login": "登录",
@@ -208,7 +209,50 @@
     "pointsCalendar": "打卡日历",
     "setupCheckinReminder": "设置打卡提醒",
     "checkinReminder": "打卡提醒",
-    "setTime": "设置时间"
+    "setTime": "设置时间",
+    "todayPlan": {
+      "title": "Today's Plan",
+      "subtitle": "A focused path through your next best tasks",
+      "footer": "Built from your reviews, courses, skills, and challenges.",
+      "viewAll": "View plan",
+      "heroTitle": "Your study route is ready",
+      "heroSubtitle": "Finish the next small task, then let LexiLingo guide you into the right practice.",
+      "completedSummary": "{completed}/{total} tasks complete",
+      "startNext": "Start next task",
+      "sequenceTitle": "Today's sequence",
+      "vocabularyTitle": "Review vocabulary",
+      "vocabularyCheckSubtitle": "Check if any words are due for review.",
+      "vocabularyDueSubtitle": "{count} words are waiting for review.",
+      "vocabularyDoneSubtitle": "You're caught up on vocabulary today.",
+      "vocabularyMeta": "SRS",
+      "courseFallbackTitle": "Choose a course",
+      "courseFallbackSubtitle": "Pick a CEFR path and start your first lesson.",
+      "courseSubtitle": "Continue your {level} learning path.",
+      "courseMeta": "Course",
+      "courseProgress": "{percent}% done",
+      "skillFallbackTitle": "Practice speaking",
+      "skillFallbackSubtitle": "Warm up with a short pronunciation drill.",
+      "skillTitle": "Strengthen {skill}",
+      "skillSubtitle": "Current estimate: {level}.",
+      "skillMeta": "Skill",
+      "skillScore": "{score}/100",
+      "challengeFallbackTitle": "Play a quick game",
+      "challengeFallbackSubtitle": "Earn XP with a short English challenge.",
+      "challengeMeta": "Challenge",
+      "challengeProgress": "{current}/{target}",
+      "lexiTitle": "Chat with Lexi",
+      "lexiSubtitle": "Close the loop with a short AI conversation.",
+      "lexiMeta": "AI Tutor",
+      "reviewAction": "Review",
+      "checkAction": "Check",
+      "browseAction": "Browse",
+      "continueAction": "Continue",
+      "practiceAction": "Practice",
+      "playAction": "Play",
+      "startAction": "Start",
+      "doneAction": "Done",
+      "chatAction": "Chat"
+    }
   },
   "course": {
     "title": "课程",
@@ -357,7 +401,10 @@
     "playbackSpeedDescription": "调整文本转语音音频播放的速度",
     "selectPlaybackSpeed": "选择播放速度",
     "confidence": "置信度：{percent}%",
-    "playError": "播放失败：{error}"
+    "playError": "播放失败：{error}",
+    "tapToRecord": "Tap to record",
+    "tapToStop": "Tap to stop",
+    "assessmentFailed": "Pronunciation assessment failed. Please try again."
   },
   "chat": {
     "placeholder": "输入消息...",
@@ -619,7 +666,19 @@
     "earnTipFinishCourse": "完成一门课程",
     "earnTipStreakBonus": "每日连续奖励",
     "earnTipAchievements": "解锁成就",
-    "earnTipChallenges": "每周挑战"
+    "earnTipChallenges": "每周挑战",
+    "dailyStreakRewardAvailable": "Daily Streak Reward!",
+    "dailyStreakRewardSubtitle": "You've kept your streak alive! Claim your daily reward now.",
+    "claimDailyRewardButton": "Claim Daily Reward",
+    "dailyRewardClaimed": "Daily Reward Claimed!",
+    "gemsReceived": "You received {gems} gems!",
+    "starterReward": {
+      "title": "Welcome gift!",
+      "description": "Use Gems to unlock special items in the shop.",
+      "action": "Awesome!",
+      "gemLabel": "Gem reward",
+      "confirmation": "{gems} Gems were added to your wallet."
+    }
   },
   "social": {
     "friends": "好友",
@@ -668,7 +727,29 @@
     "skipTour": "跳过导览",
     "activeUsers": "活跃用户",
     "dailyLessons": "每日课程",
-    "globalCommunity": "加入全球学习社区"
+    "globalCommunity": "加入全球学习社区",
+    "personalizeTitle": "个性化你的学习",
+    "goalQuestion": "你的目标是什么？",
+    "goalSubtitle": "我们会根据你的选择定制学习体验。",
+    "levelQuestion": "你目前的水平是什么？",
+    "levelSubtitle": "这有助于我们从一开始就设置合适的内容难度。",
+    "interestQuestion": "你最喜欢哪些主题？",
+    "interestSubtitle": "我们会优先推荐与你兴趣相关的课程。",
+    "continueBtn": "继续",
+    "createPlan": "创建我的计划",
+    "goalCareer": "职业",
+    "goalTravel": "旅行",
+    "goalExams": "考试",
+    "goalCulture": "文化",
+    "levelA1": "A1 - 初学者",
+    "levelA2": "A2 - 基础",
+    "levelB1": "B1 - 中级",
+    "levelB2": "B2 - 中高级",
+    "levelC1": "C1 - 高级",
+    "interestDailyLife": "日常生活与社交话题",
+    "interestTechnology": "科技与创新",
+    "interestCulture": "文化与娱乐",
+    "interestCareer": "职业发展与面试"
   },
   "preAuth": {
     "quickSetup": "快速设置",
@@ -725,7 +806,21 @@
     "readingSpeed": "阅读速度",
     "retakeTest": "重新测试",
     "yourLevelIs": "你的等级是 {level}",
-    "testCompleted": "测试完成"
+    "testCompleted": "测试完成",
+    "questionCounter": "Question {current} of {total}",
+    "answeredCount": "{answered}/{total} answered",
+    "points": "{points} pts",
+    "previous": "Previous",
+    "next": "Next",
+    "submitTest": "Submit test",
+    "answerAllQuestions": "Answer every question before submitting.",
+    "resultSubtitle": "Your CEFR profile has been updated from this assessment.",
+    "score": "Score",
+    "correct": "Correct",
+    "rank": "Rank",
+    "loadFailed": "Could not load the test",
+    "noQuestions": "No questions available",
+    "noQuestionsSubtitle": "Try again in a moment."
   },
   "premium": {
     "title": "(Premium) Go Premium",
@@ -777,7 +872,10 @@
     "categoryPowerUps": "通电",
     "categoryBoosts": "提升",
     "categoryCosmetics": "化妆品",
-    "categorySpecial": "特别的"
+    "categorySpecial": "特别的",
+    "equipNow": "Equip now",
+    "avatarEquipped": "Avatar equipped successfully!",
+    "avatarEquipFailed": "Could not equip this avatar."
   },
   "leaderboard": {
     "title": "排行榜",
@@ -867,7 +965,9 @@
     "streakLabel": "条纹",
     "streakBonusLabel": "连胜奖金：{multiplier}x",
     "playAgainButton": "再玩一次",
-    "backToGamesButton": "返回游戏"
+    "backToGamesButton": "返回游戏",
+    "xpNotAwarded": "XP was not awarded. Your game result is preserved.",
+    "retryXp": "Retry XP award"
   },
   "spellingBee": {
     "wordProgress": "字{current}/{total}",
@@ -877,7 +977,15 @@
     "correctFeedback": "正确的！",
     "answerRevealLabel": "答案是：",
     "nextWordButton": "下一个字",
-    "seeResultsButton": "查看结果"
+    "seeResultsButton": "查看结果",
+    "audioError": "Could not play audio. Check your connection.",
+    "retryAudio": "Retry",
+    "listenButtonLabel": "Listen to the word",
+    "noPlaysLeft": "No plays remaining",
+    "abandonTitle": "Quit game?",
+    "abandonBody": "XP will be based on words answered correctly so far.",
+    "keepPlaying": "Keep playing",
+    "quit": "Quit"
   },
   "wordScramble": {
     "wordProgress": "{total}的字{current}",
@@ -1045,7 +1153,10 @@
     "unlockGoldenChest": "黄金宝箱",
     "unlockGems": "50 宝石",
     "unlockXpBooster": "2倍 XP 加成",
-    "continueJourney": "继续学习"
+    "continueJourney": "继续学习",
+    "loadFailed": "Unable to load this game. Please try again.",
+    "emptyGame": "This game has no playable content right now.",
+    "retryLoad": "Try again"
   },
   "learning": {
     "checkAnswer": "检查答案",
@@ -1072,7 +1183,8 @@
     "backToBook": "返回预订",
     "readerSettings": "读卡器设置",
     "pageProgress": "{total} 的页面 {current}",
-    "searchPlaceholder": "按标题或作者搜索..."
+    "searchPlaceholder": "按标题或作者搜索...",
+    "savedBooks": "已保存的书籍"
   },
   "news": {
     "title": "英文新闻",
@@ -1146,11 +1258,165 @@
     "topicScienceSubtitle": "概念与发现",
     "topicTechnology": "技术",
     "topicTechnologySubtitle": "软件与数字时代",
-    "noDefinitionYet": "暂无释义"
+    "noDefinitionYet": "暂无释义",
+    "translationLabel": "翻译",
+    "tabWords": "Words",
+    "tabTopics": "Topic Flashcards",
+    "startLearning": "Start",
+    "audioQuestionHint": "Listen and guess the word"
   },
   "legal": {
     "privacy_title": "隐私政策",
     "terms_title": "服务条款",
     "last_updated": "最后更新: {date}"
+  },
+  "offlineSync": {
+    "title": "Offline & Sync",
+    "settingsTitle": "Offline & Sync",
+    "settingsSubtitle": "Manage cache and pending sync",
+    "entrySubtitle": "Review offline data, cache, and queued updates",
+    "onlineTitle": "You are online",
+    "onlineSubtitle": "Fresh content and queued changes can sync normally.",
+    "offlineTitle": "You are offline",
+    "offlineSubtitle": "Cached content can still open; new changes may wait in the queue.",
+    "cacheTitle": "API cache",
+    "cacheSubtitle": "Cached content used for faster loading and offline fallback.",
+    "totalEntries": "Total entries",
+    "noCache": "No cached API responses yet.",
+    "clearExpired": "Clear expired",
+    "clearAll": "Clear all",
+    "clearAllTitle": "Clear all cached API data?",
+    "clearAllMessage": "This removes cached public content. Your account, saved progress, and pending sync queue are not deleted.",
+    "clearAllConfirm": "Clear cache",
+    "expiredCleared": "Cleared {count} expired cache entries.",
+    "allCacheCleared": "All API cache entries were cleared.",
+    "queueTitle": "Sync queue",
+    "queueSubtitle": "Pending offline actions waiting to be sent.",
+    "totalQueued": "Total queued",
+    "readyQueued": "Ready now",
+    "scheduledQueued": "Scheduled retry",
+    "retryingQueued": "Retrying",
+    "queueHint": "Queued work is processed automatically when the app is online and the account is active.",
+    "queueUnavailable": "Persistent sync queue is not available on this platform.",
+    "noUserScope": "Sign in to see account-scoped sync queue status.",
+    "loadFailed": "Could not load offline status",
+    "cacheTypes": {
+      "news": "News",
+      "youtube": "YouTube",
+      "podcast": "Podcast",
+      "book": "Books",
+      "dictionary": "Dictionary",
+      "game": "Games",
+      "flashcard": "Flashcards"
+    }
+  },
+  "practiceLab": {
+    "title": "Practice Lab",
+    "shortTitle": "Practice",
+    "heroTitle": "Train by skill",
+    "heroSubtitle": "Pick the exact skill you want to sharpen, or follow the focus areas from your CEFR profile.",
+    "currentLevel": "Current level",
+    "recommended": "Focus skills",
+    "recommendedTitle": "Recommended practice",
+    "recommendedSubtitle": "Based on your weakest proficiency scores.",
+    "fallbackSubtitle": "Practice a balanced mix while LexiLingo learns your strengths.",
+    "allSkillsTitle": "All skill labs",
+    "allSkillsSubtitle": "Jump into a focused practice mode using existing lessons, games, audio, and Lexi.",
+    "focus": "Focus",
+    "premiumOnly": "Premium",
+    "premiumLockedSubtitle": "Unlock advanced Lexi-guided writing practice with Premium.",
+    "unlockPremium": "Unlock Premium",
+    "skills": {
+      "vocabulary": {
+        "title": "Vocabulary",
+        "subtitle": "Review due words and strengthen recall.",
+        "action": "Review words",
+        "estimate": "5-8 min"
+      },
+      "speaking": {
+        "title": "Speaking",
+        "subtitle": "Practice pronunciation and spoken responses.",
+        "action": "Speak now",
+        "estimate": "6-10 min"
+      },
+      "listening": {
+        "title": "Listening",
+        "subtitle": "Train your ear with graded podcast content.",
+        "action": "Listen",
+        "estimate": "8-12 min"
+      },
+      "reading": {
+        "title": "Reading",
+        "subtitle": "Read CEFR-graded news and check comprehension.",
+        "action": "Read",
+        "estimate": "7-10 min"
+      },
+      "grammar": {
+        "title": "Grammar",
+        "subtitle": "Use games and quizzes to reinforce structure.",
+        "action": "Practice",
+        "estimate": "5-9 min"
+      },
+      "writing": {
+        "title": "Writing",
+        "subtitle": "Draft sentences with Lexi and refine your output.",
+        "action": "Open Lexi",
+        "estimate": "6-10 min"
+      },
+      "mistakes": {
+        "title": "Mistake Notebook",
+        "subtitle": "Review questions you missed in reading quizzes.",
+        "action": "Review mistakes",
+        "estimate": "4-8 min"
+      }
+    }
+  },
+  "mistakeNotebook": {
+    "title": "Mistake Notebook",
+    "heroTitle": "Turn misses into review",
+    "heroSubtitle": "Wrong answers from book and news quizzes are saved here for quick follow-up.",
+    "total": "Total",
+    "toReview": "To review",
+    "reviewed": "Reviewed",
+    "reviewedTimes": "Reviewed {count} times",
+    "filterAll": "All",
+    "filterToReview": "To review",
+    "filterReviewed": "Reviewed",
+    "emptyTitle": "No mistakes yet",
+    "emptySubtitle": "Missed quiz answers from Books and News will appear here automatically.",
+    "emptyFilterTitle": "Nothing in this filter",
+    "emptyFilterSubtitle": "Switch filters to see the rest of your notebook.",
+    "sourceBookQuiz": "Book quiz",
+    "sourceNewsQuiz": "News quiz",
+    "sourceFillBlank": "Fill in the Blank",
+    "sourceGrammarQuiz": "Grammar Quiz",
+    "sourceQuiz": "Quiz",
+    "yourAnswer": "Your answer",
+    "correctAnswer": "Correct answer",
+    "explanation": "Explanation",
+    "markReviewed": "Mark reviewed",
+    "delete": "Delete",
+    "deleteTitle": "Delete mistake?",
+    "deleteMessage": "This removes the item from your notebook."
+  },
+  "vocabQuiz": {
+    "title": "Vocabulary Quiz",
+    "loading": "Building your quiz...",
+    "empty": "No words due for review!",
+    "tryAgain": "Try again",
+    "term": "TERM",
+    "definition": "DEFINITION",
+    "chooseCorrect": "Choose the correct answer",
+    "continueLabel": "Continue",
+    "finish": "Finish",
+    "correct": "Correct!",
+    "incorrect": "Not quite",
+    "exitTitle": "Exit quiz?",
+    "exitMessage": "Your progress so far is saved. Are you sure you want to exit?",
+    "chooseMode": "Choose a review mode",
+    "modeQuizTitle": "Multiple-choice quiz",
+    "modeQuizSubtitle": "Test meaning and term — auto-graded",
+    "modeFlashcardTitle": "Flashcards",
+    "modeFlashcardSubtitle": "Flip cards and rate yourself"
   }
 }
diff --git a/flutter-app/lib/core/network/interceptors/logging_interceptor.dart b/flutter-app/lib/core/network/interceptors/logging_interceptor.dart
index 792a543e..e512d1e6 100644
--- a/flutter-app/lib/core/network/interceptors/logging_interceptor.dart
+++ b/flutter-app/lib/core/network/interceptors/logging_interceptor.dart
@@ -14,8 +14,10 @@ class LoggingInterceptor implements ApiInterceptor {
   void onRequest(ApiRequest request) {
     if (!enabled) return;
     logDebug(tag, '[REQ] ${request.method} ${request.uri}');
+    final headers = _redactHeaders(request.headers);
+    final body = _isSensitivePath(request.uri) ? '<redacted>' : request.body;
     log(
-      '[REQ] ${request.method} ${request.uri} headers=${request.headers} body=${request.body}',
+      '[REQ] ${request.method} ${request.uri} headers=$headers body=$body',
       name: tag,
     );
   }
@@ -24,10 +26,10 @@ class LoggingInterceptor implements ApiInterceptor {
   void onResponse(ApiResponse response) {
     if (!enabled) return;
     logDebug(tag, '[RES] ${response.statusCode} ${response.uri}');
-    log(
-      '[RES] ${response.statusCode} ${response.uri} body=${response.bodyPreview}',
-      name: tag,
-    );
+    final body = _isSensitivePath(response.uri)
+        ? '<redacted>'
+        : response.bodyPreview;
+    log('[RES] ${response.statusCode} ${response.uri} body=$body', name: tag);
   }
 
   @override
@@ -40,4 +42,17 @@ class LoggingInterceptor implements ApiInterceptor {
       error: error.cause,
     );
   }
+
+  bool _isSensitivePath(Uri uri) {
+    return uri.pathSegments.contains('mistakes');
+  }
+
+  Map<String, String> _redactHeaders(Map<String, String> headers) {
+    return headers.map((key, value) {
+      if (key.toLowerCase() == 'authorization') {
+        return MapEntry(key, '<redacted>');
+      }
+      return MapEntry(key, value);
+    });
+  }
 }
diff --git a/flutter-app/lib/core/network/response_models.dart b/flutter-app/lib/core/network/response_models.dart
index 11d406f1..6a712424 100644
--- a/flutter-app/lib/core/network/response_models.dart
+++ b/flutter-app/lib/core/network/response_models.dart
@@ -212,6 +212,7 @@ class ErrorCodes {
   static const String authInvalid = 'AUTH_INVALID';
   static const String authExpired = 'AUTH_EXPIRED';
   static const String authMissing = 'AUTH_MISSING';
+  static const String authForbidden = 'AUTH_FORBIDDEN';
   static const String permissionDenied = 'PERMISSION_DENIED';
 
   // Resource Errors
diff --git a/flutter-app/lib/core/services/app_navigation_service.dart b/flutter-app/lib/core/services/app_navigation_service.dart
index 48442097..6feb1e42 100644
--- a/flutter-app/lib/core/services/app_navigation_service.dart
+++ b/flutter-app/lib/core/services/app_navigation_service.dart
@@ -3,10 +3,18 @@ import 'package:flutter/material.dart';
 class AppNavigationService {
   static final navigatorKey = GlobalKey<NavigatorState>();
 
-  static Future<void> openRoute(String route, {Object? arguments}) async {
+  static Future<bool> openRoute(String route, {Object? arguments}) async {
     final navigator = navigatorKey.currentState;
-    if (navigator == null) return;
-    await navigator.pushNamed(route, arguments: arguments);
+    if (navigator == null) return false;
+
+    try {
+      await navigator.pushNamed(route, arguments: arguments);
+      return true;
+    } catch (error, stackTrace) {
+      debugPrint('Failed to open route "$route": $error');
+      debugPrintStack(stackTrace: stackTrace);
+      return false;
+    }
   }
 
   static void returnToRoot() {
diff --git a/flutter-app/lib/core/services/background_sync_queue_service.dart b/flutter-app/lib/core/services/background_sync_queue_service.dart
index 3f59d3f6..8697ff4c 100644
--- a/flutter-app/lib/core/services/background_sync_queue_service.dart
+++ b/flutter-app/lib/core/services/background_sync_queue_service.dart
@@ -27,6 +27,30 @@ class SyncQueueItem {
   final DateTime nextRetryAt;
 }
 
+class SyncQueueSummary {
+  const SyncQueueSummary({
+    required this.persistentQueueAvailable,
+    required this.readyCount,
+    required this.scheduledCount,
+    required this.retryingCount,
+    required this.totalCount,
+  });
+
+  final bool persistentQueueAvailable;
+  final int readyCount;
+  final int scheduledCount;
+  final int retryingCount;
+  final int totalCount;
+
+  static const unsupported = SyncQueueSummary(
+    persistentQueueAvailable: false,
+    readyCount: 0,
+    scheduledCount: 0,
+    retryingCount: 0,
+    totalCount: 0,
+  );
+}
+
 /// Persistent background sync queue with exponential backoff.
 class BackgroundSyncQueueService {
   BackgroundSyncQueueService._();
@@ -99,6 +123,36 @@ class BackgroundSyncQueueService {
         .toList();
   }
 
+  Future<SyncQueueSummary> getSummary({required String userScope}) async {
+    if (!_supportsPersistentQueue) {
+      return SyncQueueSummary.unsupported;
+    }
+
+    final db = await DatabaseHelper.instance.database;
+    final now = DateTime.now().toIso8601String();
+    final rows = await db.rawQuery(
+      '''
+SELECT
+  COUNT(*) as total_count,
+  SUM(CASE WHEN next_retry_at <= ? THEN 1 ELSE 0 END) as ready_count,
+  SUM(CASE WHEN next_retry_at > ? THEN 1 ELSE 0 END) as scheduled_count,
+  SUM(CASE WHEN retry_count > 0 THEN 1 ELSE 0 END) as retrying_count
+FROM $tableName
+WHERE user_scope = ?
+''',
+      [now, now, userScope],
+    );
+
+    final row = rows.isEmpty ? const <String, Object?>{} : rows.first;
+    return SyncQueueSummary(
+      persistentQueueAvailable: true,
+      readyCount: _readCount(row['ready_count']),
+      scheduledCount: _readCount(row['scheduled_count']),
+      retryingCount: _readCount(row['retrying_count']),
+      totalCount: _readCount(row['total_count']),
+    );
+  }
+
   Future<void> processPending({
     required String userScope,
     required Future<void> Function(SyncQueueItem item) processor,
@@ -163,6 +217,12 @@ class BackgroundSyncQueueService {
     return DateTime.now().add(Duration(seconds: backoff));
   }
 
+  int _readCount(Object? value) {
+    if (value is int) return value;
+    if (value is num) return value.toInt();
+    return int.tryParse(value?.toString() ?? '') ?? 0;
+  }
+
   static Future<void> createTable(Database db) async {
     await db.execute('''
 CREATE TABLE IF NOT EXISTS $tableName (
diff --git a/flutter-app/lib/core/services/firebase_messaging_service.dart b/flutter-app/lib/core/services/firebase_messaging_service.dart
index 20fa1179..72502fb5 100644
--- a/flutter-app/lib/core/services/firebase_messaging_service.dart
+++ b/flutter-app/lib/core/services/firebase_messaging_service.dart
@@ -5,7 +5,8 @@ import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:flutter/foundation.dart' show debugPrint, kDebugMode, kIsWeb;
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:lexilingo_app/core/network/api_client.dart';
-import 'package:lexilingo_app/core/services/app_navigation_service.dart';
+import 'package:lexilingo_app/features/notifications/domain/entities/notification_entity.dart';
+import 'package:lexilingo_app/features/notifications/domain/services/notification_navigation_service.dart';
 
 /// Firebase Cloud Messaging Service
 /// Handles push notifications from Firebase
@@ -237,40 +238,27 @@ class FirebaseMessagingService {
     final data = message.data;
     debugPrint('Message data: $data');
 
-    // Parse data and navigate accordingly
-    final type = data['type'] as String?;
-    // ignore: unused_local_variable
-    final targetId = data['target_id'] as String?;
-
-    switch (type) {
-      case 'starter_reward':
-        AppNavigationService.returnToRoot();
-        break;
-      case 'vocabulary_review_reminder':
-        final route = data['route'] as String? ?? '/vocabulary/review';
-        AppNavigationService.openRoute(route);
-        debugPrint('Navigate to vocabulary review screen');
-        break;
-      case 'streak_reminder':
-        // Navigate to home/streak screen
-        debugPrint('Navigate to streak screen');
-        break;
-      case 'lesson_reminder':
-        // Navigate to learning screen
-        debugPrint('Navigate to learning screen');
-        break;
-      case 'achievement':
-        // Navigate to achievements screen
-        debugPrint('Navigate to achievements screen');
-        break;
-      case 'new_content':
-        // Navigate to courses screen
-        debugPrint('Navigate to courses screen');
-        break;
-      default:
-        // Navigate to home
-        debugPrint('Navigate to home screen');
-    }
+    final notification = NotificationEntity.fromFcm(
+      id: message.messageId ?? 'fcm_${DateTime.now().microsecondsSinceEpoch}',
+      title:
+          message.notification?.title ??
+          _readDataString(data, 'title') ??
+          'Notification',
+      body: message.notification?.body ?? _readDataString(data, 'body') ?? '',
+      data: Map<String, dynamic>.from(data),
+    );
+
+    NotificationNavigationService.open(notification);
+    debugPrint(
+      'Navigate notification to ${notification.destinationRoute ?? 'root'}',
+    );
+  }
+
+  String? _readDataString(Map<String, dynamic> data, String key) {
+    final value = data[key];
+    if (value is! String) return null;
+    final trimmed = value.trim();
+    return trimmed.isEmpty ? null : trimmed;
   }
 
   /// Subscribe to a topic
diff --git a/flutter-app/lib/core/services/local_cache_service.dart b/flutter-app/lib/core/services/local_cache_service.dart
index df12d845..789d0e7d 100644
--- a/flutter-app/lib/core/services/local_cache_service.dart
+++ b/flutter-app/lib/core/services/local_cache_service.dart
@@ -252,6 +252,31 @@ class LocalCacheService {
     return Sqflite.firstIntValue(result) ?? 0;
   }
 
+  /// Get cache entry counts grouped by content type.
+  Future<Map<String, int>> getCacheCountsByType() async {
+    if (kIsWeb) {
+      final counts = <String, int>{};
+      for (final entry in _memoryCache.values) {
+        counts.update(
+          entry.contentType,
+          (value) => value + 1,
+          ifAbsent: () => 1,
+        );
+      }
+      return counts;
+    }
+
+    final db = await DatabaseHelper.instance.database;
+    final rows = await db.rawQuery(
+      'SELECT content_type, COUNT(*) as count FROM $_tableName GROUP BY content_type',
+    );
+
+    return {
+      for (final row in rows)
+        row['content_type'] as String: (row['count'] as int?) ?? 0,
+    };
+  }
+
   /// Clear all cache data.
   Future<void> clearAll() async {
     if (kIsWeb) {
diff --git a/flutter-app/lib/core/widgets/game_icon.dart b/flutter-app/lib/core/widgets/game_icon.dart
index 4147ae18..4b04b4f2 100644
--- a/flutter-app/lib/core/widgets/game_icon.dart
+++ b/flutter-app/lib/core/widgets/game_icon.dart
@@ -45,11 +45,28 @@ enum GameIcon {
   sunMorning,
   moonNight,
   book,
+  refresh,
+  trendingUp,
+  video,
+  snowflakeFreeze,
+  microphone,
+  peoplePair,
+  forwardArrow,
+  sparkle,
+  sunsetAfternoon,
+
+  // Game power-up icons (shop items usable mid-game).
+  timeFreezeClock,
+  hourglassTime,
+  lightningBoltPower,
+  magnifyingGlass,
+  shieldPowerUp,
+  luckyClover,
+  swapArrow,
 
   // Pending custom art — rendered with a Material fallback for now.
   newspaper,
   headphones,
-  sunsetAfternoon,
   translate,
 }
 
@@ -67,8 +84,10 @@ const Map<GameIcon, String> _assetPath = {
   GameIcon.padlockUnlocked: 'assets/icon-library/unlocked_padlock.png',
   GameIcon.clock: 'assets/icon-library/clock.png',
   GameIcon.lessonBoard: 'assets/icon-library/chalkboard_abc.png',
+  GameIcon.playArrow: 'assets/icon-library/button/triangle_right.png',
   GameIcon.fastForward: 'assets/icon-library/button/fast_forward_button.png',
   GameIcon.rewind: 'assets/icon-library/button/rewind_button.png',
+  GameIcon.backArrow: 'assets/icon-library/button/left_arrow.png',
   GameIcon.nextButton: 'assets/icon-library/button/next_button.png',
   GameIcon.prevButton: 'assets/icon-library/button/prev_button.png',
   GameIcon.speakerOn: 'assets/icon-library/speaker_on.png',
@@ -89,21 +108,99 @@ const Map<GameIcon, String> _assetPath = {
   GameIcon.sunMorning: 'assets/icon-library/yellow_sun.png',
   GameIcon.moonNight: 'assets/icon-library/crescent_moon.png',
   GameIcon.book: 'assets/icon-library/blue_book.png',
+  GameIcon.refresh: 'assets/icon-library/button/refresh_arrow.png',
+  GameIcon.trendingUp: 'assets/icon-library/double_up_arrow.png',
+  GameIcon.video: 'assets/icon-library/clapperboard.png',
+  GameIcon.snowflakeFreeze: 'assets/icon-library/snowflake_badge.png',
+  GameIcon.microphone: 'assets/icon-library/microphone.png',
+  GameIcon.peoplePair: 'assets/icon-library/character_pair.png',
+  GameIcon.forwardArrow: 'assets/icon-library/button/right_arrow.png',
+  GameIcon.sparkle: 'assets/icon-library/sparkles.png',
+  GameIcon.sunsetAfternoon: 'assets/icon-library/sun.png',
+  GameIcon.timeFreezeClock: 'assets/icon-library/clock_freeze.png',
+  GameIcon.hourglassTime: 'assets/icon-library/hourglass.png',
+  GameIcon.lightningBoltPower: 'assets/icon-library/lightning_bolt.png',
+  GameIcon.magnifyingGlass: 'assets/icon-library/magnifying_glass.png',
+  GameIcon.shieldPowerUp: 'assets/icon-library/shield.png',
+  GameIcon.luckyClover: 'assets/icon-library/four_leaf_clover.png',
+  GameIcon.swapArrow: 'assets/icon-library/swap_arrow.png',
 };
 
 const Map<GameIcon, IconData> _fallbackIcon = {
-  // playArrow/backArrow: the previous pack's plain UI-arrow icons (plain
-  // triangle, curved back arrow) have no equivalent in the current
-  // icon-library — it's all game items/badges now. Falls back until a
-  // dedicated UI-arrow asset is supplied.
+  GameIcon.star: Icons.star_rounded,
+  GameIcon.trophy: Icons.emoji_events_rounded,
+  GameIcon.xp: Icons.bolt_rounded,
+  GameIcon.gem: Icons.diamond_rounded,
+  GameIcon.crown: Icons.workspace_premium_rounded,
+  GameIcon.checkmark: Icons.check_circle_rounded,
+  GameIcon.giftBox: Icons.card_giftcard_rounded,
+  GameIcon.treasureChest: Icons.inventory_2_rounded,
+  GameIcon.speechBubble: Icons.chat_bubble_rounded,
+  GameIcon.settings: Icons.settings_rounded,
+  GameIcon.padlockUnlocked: Icons.lock_open_rounded,
+  GameIcon.clock: Icons.schedule_rounded,
+  GameIcon.lessonBoard: Icons.menu_book_rounded,
   GameIcon.playArrow: Icons.play_arrow_rounded,
+  GameIcon.fastForward: Icons.fast_forward_rounded,
+  GameIcon.rewind: Icons.fast_rewind_rounded,
   GameIcon.backArrow: Icons.arrow_back_rounded,
+  GameIcon.nextButton: Icons.navigate_next_rounded,
+  GameIcon.prevButton: Icons.navigate_before_rounded,
+  GameIcon.speakerOn: Icons.volume_up_rounded,
+  GameIcon.speakerMuted: Icons.volume_off_rounded,
+  GameIcon.lightBulb: Icons.lightbulb_rounded,
+  GameIcon.heart: Icons.favorite_rounded,
+  GameIcon.flashcards: Icons.style_rounded,
+  GameIcon.grammar: Icons.spellcheck_rounded,
+  GameIcon.listening: Icons.headphones_rounded,
+  GameIcon.quizzes: Icons.quiz_rounded,
+  GameIcon.speaking: Icons.mic_rounded,
+  GameIcon.vocabulary: Icons.translate_rounded,
+  GameIcon.streakFire: Icons.local_fire_department_rounded,
+  GameIcon.bolt: Icons.bolt_rounded,
+  GameIcon.gameController: Icons.sports_esports_rounded,
+  GameIcon.notificationBell: Icons.notifications_rounded,
+  GameIcon.calendar: Icons.calendar_month_rounded,
+  GameIcon.sunMorning: Icons.wb_sunny_rounded,
+  GameIcon.moonNight: Icons.nightlight_round,
+  GameIcon.book: Icons.book_rounded,
+  GameIcon.refresh: Icons.refresh_rounded,
+  GameIcon.trendingUp: Icons.trending_up_rounded,
+  GameIcon.video: Icons.videocam_rounded,
+  GameIcon.snowflakeFreeze: Icons.ac_unit_rounded,
+  GameIcon.microphone: Icons.mic_rounded,
+  GameIcon.peoplePair: Icons.people_rounded,
+  GameIcon.forwardArrow: Icons.arrow_forward_rounded,
+  GameIcon.sparkle: Icons.auto_awesome_rounded,
+  GameIcon.sunsetAfternoon: Icons.wb_twilight_rounded,
+  GameIcon.timeFreezeClock: Icons.more_time_rounded,
+  GameIcon.hourglassTime: Icons.hourglass_bottom_rounded,
+  GameIcon.lightningBoltPower: Icons.flash_on_rounded,
+  GameIcon.magnifyingGlass: Icons.search_rounded,
+  GameIcon.shieldPowerUp: Icons.shield_rounded,
+  GameIcon.luckyClover: Icons.local_florist_rounded,
+  GameIcon.swapArrow: Icons.swap_horiz_rounded,
   GameIcon.newspaper: Icons.article_rounded,
   GameIcon.headphones: Icons.headphones_rounded,
-  GameIcon.sunsetAfternoon: Icons.wb_twilight_rounded,
   GameIcon.translate: Icons.translate_rounded,
 };
 
+/// Maps a shop `item_type` string for an in-game power-up (time_freeze,
+/// skip_token, reveal_hint, ...) to its [GameIcon]. Shared by the shop
+/// item card and the in-game power-up tray so both render the same art.
+const Map<String, GameIcon> gamePowerUpIcons = {
+  'time_freeze': GameIcon.timeFreezeClock,
+  'extra_time': GameIcon.hourglassTime,
+  'skip_token': GameIcon.lightningBoltPower,
+  'reveal_hint': GameIcon.magnifyingGlass,
+  'translate_hint': GameIcon.speechBubble,
+  'mistake_shield': GameIcon.shieldPowerUp,
+  'extra_heart': GameIcon.heart,
+  'lucky_clover': GameIcon.luckyClover,
+  'score_multiplier': GameIcon.trendingUp,
+  'pair_swap': GameIcon.swapArrow,
+};
+
 /// Renders a custom flat game-style icon by semantic [GameIcon] key,
 /// falling back to a Material icon when no asset has been supplied yet.
 class AppGameIcon extends StatelessWidget {
@@ -111,12 +208,7 @@ class AppGameIcon extends StatelessWidget {
   final double size;
   final Color? fallbackColor;
 
-  const AppGameIcon(
-    this.icon, {
-    super.key,
-    this.size = 24,
-    this.fallbackColor,
-  });
+  const AppGameIcon(this.icon, {super.key, this.size = 24, this.fallbackColor});
 
   bool get hasCustomAsset => _assetPath.containsKey(icon);
 
@@ -124,8 +216,18 @@ class AppGameIcon extends StatelessWidget {
   Widget build(BuildContext context) {
     final path = _assetPath[icon];
     if (path != null) {
-      return Image.asset(path, width: size, height: size, fit: BoxFit.contain);
+      return Image.asset(
+        path,
+        width: size,
+        height: size,
+        fit: BoxFit.contain,
+        errorBuilder: (_, __, ___) => _buildFallbackIcon(),
+      );
     }
+    return _buildFallbackIcon();
+  }
+
+  Widget _buildFallbackIcon() {
     return Icon(
       _fallbackIcon[icon] ?? Icons.help_outline,
       size: size,
diff --git a/flutter-app/lib/core/widgets/language_switcher_button.dart b/flutter-app/lib/core/widgets/language_switcher_button.dart
index 6de09d5e..6878f093 100644
--- a/flutter-app/lib/core/widgets/language_switcher_button.dart
+++ b/flutter-app/lib/core/widgets/language_switcher_button.dart
@@ -25,116 +25,122 @@ class LanguageSwitcherButton extends StatelessWidget {
 
     showModalBottomSheet<void>(
       context: context,
+      isScrollControlled: true,
       shape: const RoundedRectangleBorder(
         borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
       ),
       backgroundColor: isDark ? AppColors.surfaceDark : AppColors.surfaceLight,
       builder: (sheetContext) {
         return SafeArea(
-          child: Padding(
-            padding: const EdgeInsets.fromLTRB(16, 12, 16, 16),
-            child: Column(
-              mainAxisSize: MainAxisSize.min,
-              children: [
-                Container(
-                  width: 36,
-                  height: 4,
-                  decoration: BoxDecoration(
-                    color: isDark ? AppColors.grey700 : AppColors.grey300,
-                    borderRadius: BorderRadius.circular(999),
+          child: ConstrainedBox(
+            constraints: BoxConstraints(
+              maxHeight: MediaQuery.of(sheetContext).size.height * 0.75,
+            ),
+            child: Padding(
+              padding: const EdgeInsets.fromLTRB(16, 12, 16, 16),
+              child: Column(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Container(
+                    width: 36,
+                    height: 4,
+                    decoration: BoxDecoration(
+                      color: isDark ? AppColors.grey700 : AppColors.grey300,
+                      borderRadius: BorderRadius.circular(999),
+                    ),
                   ),
-                ),
-                const SizedBox(height: 16),
-                Text(
-                  'settings.language'.tr(),
-                  style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                    fontWeight: FontWeight.bold,
-                    color: isDark ? Colors.white : AppColors.textDark,
+                  const SizedBox(height: 16),
+                  Text(
+                    'settings.language'.tr(),
+                    style: Theme.of(context).textTheme.titleMedium?.copyWith(
+                      fontWeight: FontWeight.bold,
+                      color: isDark ? Colors.white : AppColors.textDark,
+                    ),
                   ),
-                ),
-                const SizedBox(height: 8),
-                Flexible(
-                  child: SingleChildScrollView(
-                    child: Column(
-                      mainAxisSize: MainAxisSize.min,
-                      children: AppLocales.supportedLocales.map((locale) {
-                        final code = locale.languageCode;
-                        final name = AppLocales.nameOf(code);
-                        final nameEn = AppLocales.nameEnOf(code);
-                        final isSelected = code == currentCode;
+                  const SizedBox(height: 8),
+                  Flexible(
+                    child: SingleChildScrollView(
+                      child: Column(
+                        mainAxisSize: MainAxisSize.min,
+                        children: AppLocales.supportedLocales.map((locale) {
+                          final code = locale.languageCode;
+                          final name = AppLocales.nameOf(code);
+                          final nameEn = AppLocales.nameEnOf(code);
+                          final isSelected = code == currentCode;
 
-                        return Material(
-                          color: Colors.transparent,
-                          child: ListTile(
-                            contentPadding: const EdgeInsets.symmetric(
-                              horizontal: 8,
-                              vertical: 2,
-                            ),
-                            shape: RoundedRectangleBorder(
-                              borderRadius: BorderRadius.circular(12),
-                            ),
-                            tileColor: isSelected
-                                ? AppColors.accentMint.withValues(
-                                    alpha: isDark ? 0.08 : 0.06,
-                                  )
-                                : null,
-                            leading: Container(
-                              width: 44,
-                              height: 44,
-                              alignment: Alignment.center,
-                              decoration: BoxDecoration(
-                                color: isSelected
-                                    ? AppColors.accentMint.withValues(
-                                        alpha: isDark ? 0.2 : 0.15,
-                                      )
-                                    : Colors.transparent,
+                          return Material(
+                            color: Colors.transparent,
+                            child: ListTile(
+                              contentPadding: const EdgeInsets.symmetric(
+                                horizontal: 8,
+                                vertical: 2,
+                              ),
+                              shape: RoundedRectangleBorder(
                                 borderRadius: BorderRadius.circular(12),
                               ),
-                              child: _FlagImage(
-                                languageCode: code,
-                                width: 28,
-                                height: 20,
+                              tileColor: isSelected
+                                  ? AppColors.accentMint.withValues(
+                                      alpha: isDark ? 0.08 : 0.06,
+                                    )
+                                  : null,
+                              leading: Container(
+                                width: 44,
+                                height: 44,
+                                alignment: Alignment.center,
+                                decoration: BoxDecoration(
+                                  color: isSelected
+                                      ? AppColors.accentMint.withValues(
+                                          alpha: isDark ? 0.2 : 0.15,
+                                        )
+                                      : Colors.transparent,
+                                  borderRadius: BorderRadius.circular(12),
+                                ),
+                                child: _FlagImage(
+                                  languageCode: code,
+                                  width: 28,
+                                  height: 20,
+                                ),
                               ),
-                            ),
-                            title: Text(
-                              name,
-                              style: TextStyle(
-                                fontWeight: FontWeight.w600,
-                                color: isSelected
-                                    ? AppColors.accentMint
-                                    : isDark
-                                    ? Colors.white
-                                    : AppColors.textDark,
+                              title: Text(
+                                name,
+                                style: TextStyle(
+                                  fontWeight: FontWeight.w600,
+                                  color: isSelected
+                                      ? AppColors.accentMint
+                                      : isDark
+                                      ? Colors.white
+                                      : AppColors.textDark,
+                                ),
                               ),
+                              subtitle: name != nameEn
+                                  ? Text(
+                                      nameEn,
+                                      style: TextStyle(
+                                        color: isDark
+                                            ? AppColors.textMuted
+                                            : AppColors.textSlateLight,
+                                        fontSize: 12,
+                                      ),
+                                    )
+                                  : null,
+                              trailing: isSelected
+                                  ? const Icon(
+                                      Icons.check_rounded,
+                                      color: AppColors.accentMint,
+                                    )
+                                  : null,
+                              onTap: () {
+                                Navigator.of(sheetContext).pop();
+                                _applyLanguage(context, code);
+                              },
                             ),
-                            subtitle: name != nameEn
-                                ? Text(
-                                    nameEn,
-                                    style: TextStyle(
-                                      color: isDark
-                                          ? AppColors.textMuted
-                                          : AppColors.textSlateLight,
-                                      fontSize: 12,
-                                    ),
-                                  )
-                                : null,
-                            trailing: isSelected
-                                ? const Icon(
-                                    Icons.check_rounded,
-                                    color: AppColors.accentMint,
-                                  )
-                                : null,
-                            onTap: () {
-                              Navigator.of(sheetContext).pop();
-                              _applyLanguage(context, code);
-                            },
-                          ),
-                        );
-                      }).toList(),
+                          );
+                        }).toList(),
+                      ),
                     ),
                   ),
-                ),
-              ],
+                ],
+              ),
             ),
           ),
         );
diff --git a/flutter-app/lib/core/widgets/premium_gate.dart b/flutter-app/lib/core/widgets/premium_gate.dart
index 28bfca79..195e3e90 100644
--- a/flutter-app/lib/core/widgets/premium_gate.dart
+++ b/flutter-app/lib/core/widgets/premium_gate.dart
@@ -31,17 +31,25 @@ class _PremiumGateState extends State<PremiumGate> {
 
   @override
   Widget build(BuildContext context) {
+    if (_isPremium == null && widget.lockedChild != null) {
+      return _buildLockedContent();
+    }
     if (_isPremium == null) return const SizedBox.shrink();
     if (_isPremium!) return widget.child;
 
+    return _buildLockedContent();
+  }
+
+  Widget _buildLockedContent() {
     return GestureDetector(
       onTap: () async {
-        final unlocked = await Navigator.of(context).push<bool>(
-          MaterialPageRoute(builder: (_) => const PaywallScreen()),
-        );
+        final unlocked = await Navigator.of(
+          context,
+        ).push<bool>(MaterialPageRoute(builder: (_) => const PaywallScreen()));
         if (unlocked == true) _check();
       },
-      child: widget.lockedChild ??
+      child:
+          widget.lockedChild ??
           ColoredBox(
             color: Colors.black12,
             child: Stack(
diff --git a/flutter-app/lib/features/admin/features/auth/presentation/login_screen.dart b/flutter-app/lib/features/admin/features/auth/presentation/login_screen.dart
index c4f45785..89c9779a 100644
--- a/flutter-app/lib/features/admin/features/auth/presentation/login_screen.dart
+++ b/flutter-app/lib/features/admin/features/auth/presentation/login_screen.dart
@@ -113,8 +113,8 @@ class LoginScreen extends StatelessWidget {
                                   crossAxisAlignment: CrossAxisAlignment.start,
                                   children: [
                                     Image.asset(
-                                      'assets/out-app/LexiLingo-logo.png',
-                                      height: 30,
+                                      'assets/out-app/lexilingo-logo.png',
+                                      height: 22,
                                       fit: BoxFit.contain,
                                     ),
                                     Text(
diff --git a/flutter-app/lib/features/auth/data/models/user_model.dart b/flutter-app/lib/features/auth/data/models/user_model.dart
index a4f750ce..a09d4e7e 100644
--- a/flutter-app/lib/features/auth/data/models/user_model.dart
+++ b/flutter-app/lib/features/auth/data/models/user_model.dart
@@ -14,6 +14,7 @@ class UserModel extends UserEntity {
     super.isOnboardingCompleted,
     super.roleSlug,
     super.cefrLevel,
+    super.nativeLanguage,
     super.totalXp,
     super.numericLevel,
     super.currentStreak,
@@ -69,6 +70,7 @@ class UserModel extends UserEntity {
           _optionalString(json['role']) ??
           'user',
       cefrLevel: _optionalString(json['cefr_level']) ?? 'A1',
+      nativeLanguage: _optionalString(json['native_language']) ?? 'vi',
       totalXp: json['total_xp'] as int? ?? 0,
       numericLevel: json['numeric_level'] as int? ?? 1,
       currentStreak: json['current_streak'] as int? ?? 0,
@@ -99,6 +101,7 @@ class UserModel extends UserEntity {
       'role_slug': roleSlug,
       'cefr_level': cefrLevel,
       'level': cefrLevel,
+      'native_language': nativeLanguage,
       'total_xp': totalXp,
       'numeric_level': numericLevel,
       'current_streak': currentStreak,
@@ -122,6 +125,7 @@ class UserModel extends UserEntity {
       isOnboardingCompleted: entity.isOnboardingCompleted,
       roleSlug: entity.roleSlug,
       cefrLevel: entity.cefrLevel,
+      nativeLanguage: entity.nativeLanguage,
       totalXp: entity.totalXp,
       numericLevel: entity.numericLevel,
       currentStreak: entity.currentStreak,
diff --git a/flutter-app/lib/features/auth/data/repositories/auth_repository_impl.dart b/flutter-app/lib/features/auth/data/repositories/auth_repository_impl.dart
index f43bb9ac..d48737ac 100644
--- a/flutter-app/lib/features/auth/data/repositories/auth_repository_impl.dart
+++ b/flutter-app/lib/features/auth/data/repositories/auth_repository_impl.dart
@@ -21,38 +21,21 @@ class AuthRepositoryImpl implements AuthRepository {
     String? displayName,
   }) async {
     try {
-      // Step 1: Create account on backend
-      await backendDataSource.register(
+      final user = await backendDataSource.register(
         email: email,
         username: username,
         password: password,
         displayName: displayName,
       );
-
-      // Step 2: Auto-login to obtain JWT tokens, so the user is fully
-      // authenticated immediately after registration (no second login needed).
-      final loginResponse = await backendDataSource.login(
-        email: email,
-        password: password,
-      );
-
-      // Step 3: Fetch full profile (same pattern as login)
-      UserEntity user;
-      try {
-        user = await backendDataSource.getCurrentUser();
-      } on ServerException {
-        user = _buildFallbackUser(loginResponse);
-      }
-
       return Right(user);
     } on ApiErrorException catch (e) {
       return Left(_mapApiErrorToFailure(e));
     } on ServerException catch (e) {
       return Left(ServerFailure(e.message));
     } on UnauthorizedException catch (_) {
-      return Left(AuthFailure('Auto-login after registration failed.'));
+      return Left(AuthFailure('Registration failed.'));
     } on AuthException catch (_) {
-      return Left(AuthFailure('Auto-login after registration failed.'));
+      return Left(AuthFailure('Registration failed.'));
     } catch (e) {
       return Left(ServerFailure('Registration failed: $e'));
     }
@@ -278,6 +261,7 @@ class AuthRepositoryImpl implements AuthRepository {
       case ErrorCodes.authInvalid:
       case ErrorCodes.authExpired:
       case ErrorCodes.authMissing:
+      case ErrorCodes.authForbidden:
         return AuthFailure(e.message);
 
       case ErrorCodes.validationError:
diff --git a/flutter-app/lib/features/auth/domain/entities/user_entity.dart b/flutter-app/lib/features/auth/domain/entities/user_entity.dart
index e83e374c..8ddb3255 100644
--- a/flutter-app/lib/features/auth/domain/entities/user_entity.dart
+++ b/flutter-app/lib/features/auth/domain/entities/user_entity.dart
@@ -11,6 +11,7 @@ class UserEntity {
   final bool isOnboardingCompleted;
   final String roleSlug; // 'user', 'admin', 'super_admin'
   final String cefrLevel; // CEFR level: A1, A2, B1, B2, C1, C2
+  final String nativeLanguage; // ISO code: vi, en, ja, ko, zh, fr, es
   final int totalXp;
   final int numericLevel;
   final int currentStreak;
@@ -30,6 +31,7 @@ class UserEntity {
     this.isOnboardingCompleted = false,
     this.roleSlug = 'user',
     this.cefrLevel = 'A1',
+    this.nativeLanguage = 'vi',
     this.totalXp = 0,
     this.numericLevel = 1,
     this.currentStreak = 0,
@@ -50,6 +52,7 @@ class UserEntity {
     bool? isOnboardingCompleted,
     String? roleSlug,
     String? cefrLevel,
+    String? nativeLanguage,
     int? totalXp,
     int? numericLevel,
     int? currentStreak,
@@ -70,6 +73,7 @@ class UserEntity {
           isOnboardingCompleted ?? this.isOnboardingCompleted,
       roleSlug: roleSlug ?? this.roleSlug,
       cefrLevel: cefrLevel ?? this.cefrLevel,
+      nativeLanguage: nativeLanguage ?? this.nativeLanguage,
       totalXp: totalXp ?? this.totalXp,
       numericLevel: numericLevel ?? this.numericLevel,
       currentStreak: currentStreak ?? this.currentStreak,
diff --git a/flutter-app/lib/features/auth/presentation/pages/login_page.dart b/flutter-app/lib/features/auth/presentation/pages/login_page.dart
index 8fbae9c1..2ef4ceaf 100644
--- a/flutter-app/lib/features/auth/presentation/pages/login_page.dart
+++ b/flutter-app/lib/features/auth/presentation/pages/login_page.dart
@@ -6,6 +6,7 @@ import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import '../providers/auth_provider.dart';
+import 'email_verification_pending_page.dart';
 import 'forgot_password_page.dart';
 import 'register_page.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
@@ -57,13 +58,22 @@ class _LoginPageState extends State<LoginPage> {
         normalized.contains('auth_invalid');
   }
 
+  bool _isEmailNotVerifiedMessage(String? message) {
+    if (message == null) return false;
+    final normalized = message.toLowerCase();
+    return normalized.contains('not verified') ||
+        normalized.contains('chưa được xác thực') ||
+        normalized.contains('chưa xác thực');
+  }
+
   Future<void> _loadSavedCredentials() async {
     final prefs = await SharedPreferences.getInstance();
     final remember = prefs.getBool(_rememberPasswordKey) ?? false;
     if (!remember) return;
 
     final savedEmail = prefs.getString(_savedEmailKey) ?? '';
-    final savedPassword = await _secureStorage.read(key: _savedPasswordKey) ?? '';
+    final savedPassword =
+        await _secureStorage.read(key: _savedPasswordKey) ?? '';
 
     if (!mounted) return;
     setState(() {
@@ -125,17 +135,21 @@ class _LoginPageState extends State<LoginPage> {
     // the social-login row on screen; above `_roomyHeight` everything uses
     // full spacing; in between it scales continuously so it looks right on
     // every device size, not just two presets.
-    const roomyHeight = 820.0;
-    const tightHeight = 600.0;
+    const roomyHeight = 900.0;
+    const tightHeight = 760.0;
     final mediaQuery = MediaQuery.of(context);
     final usableHeight =
         mediaQuery.size.height -
         mediaQuery.padding.top -
         mediaQuery.padding.bottom -
         mediaQuery.viewInsets.bottom;
+    final isKeyboardOpen = mediaQuery.viewInsets.bottom > 0;
     final fitT = ((usableHeight - tightHeight) / (roomyHeight - tightHeight))
         .clamp(0.0, 1.0);
-    double gap(double full, double compact) => compact + (full - compact) * fitT;
+    double gap(double full, double compact) =>
+        compact + (full - compact) * fitT;
+    final logoHeight = gap(40, 32);
+    final heroHeight = isKeyboardOpen ? 0.0 : gap(320, 185);
 
     return Scaffold(
       key: ValueKey<String>('login-page-$localeCode'),
@@ -147,7 +161,10 @@ class _LoginPageState extends State<LoginPage> {
           child: ConstrainedBox(
             constraints: const BoxConstraints(maxWidth: 480),
             child: SingleChildScrollView(
-              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+              padding: EdgeInsets.symmetric(
+                horizontal: 16,
+                vertical: gap(8, 4),
+              ),
               child: Form(
                 key: _formKey,
                 child: Column(
@@ -170,8 +187,8 @@ class _LoginPageState extends State<LoginPage> {
                         Expanded(
                           child: Center(
                             child: Image.asset(
-                              'assets/out-app/LexiLingo-logo.png',
-                              height: 40,
+                              'assets/out-app/lexilingo-logo.png',
+                              height: logoHeight,
                               fit: BoxFit.contain,
                               color: isDark ? Colors.white : null,
                             ),
@@ -181,28 +198,30 @@ class _LoginPageState extends State<LoginPage> {
                       ],
                     ),
 
-                    SizedBox(height: gap(8, 4)),
-
-                    // Hero
-                    ClipRRect(
-                      borderRadius: BorderRadius.circular(16),
-                      child: Container(
-                        height: gap(200, 90),
-                        decoration: BoxDecoration(
-                          gradient: const LinearGradient(
-                            colors: [Color(0x3330E8E8), Color(0x2230E8E8)],
+                    if (heroHeight > 0) ...[
+                      SizedBox(height: gap(8, 4)),
+
+                      // Hero
+                      ClipRRect(
+                        borderRadius: BorderRadius.circular(16),
+                        child: Container(
+                          height: heroHeight,
+                          decoration: BoxDecoration(
+                            gradient: const LinearGradient(
+                              colors: [Color(0x3330E8E8), Color(0x2230E8E8)],
+                            ),
+                            borderRadius: BorderRadius.circular(16),
                           ),
-                          borderRadius: BorderRadius.circular(16),
-                        ),
-                        child: Image.network(
-                          'https://lh3.googleusercontent.com/aida-public/AB6AXuC9e5sG5ITzGQOOtLmmixgmi3eqy1u2vjREx5V2LGBCdNg_bgu7OQarns0X8kgNuuuRN6bV1yWvZej9RBzXmsN0DYptA_CsuDNIuGLUOa_JlGU5R_fFBaQJZgQnWOvW6YVqMVd3tVGfLxAGrmQuwwyVsPQdEpGwB3E_bGE4Zbdw5Eya67psT55Ru81ggipsdLz1q7mHhNths64jCip1sXDvPCi_RBDeHWeza1RJmiuGVC9FfcWdVPLMLPZd2XM9pzu5ezA_FzA2O5g',
-                          fit: BoxFit.cover,
-                          errorBuilder: (context, _, __) => const Center(
-                            child: Icon(Icons.language, size: 64),
+                          child: Image.network(
+                            'https://lh3.googleusercontent.com/aida-public/AB6AXuC9e5sG5ITzGQOOtLmmixgmi3eqy1u2vjREx5V2LGBCdNg_bgu7OQarns0X8kgNuuuRN6bV1yWvZej9RBzXmsN0DYptA_CsuDNIuGLUOa_JlGU5R_fFBaQJZgQnWOvW6YVqMVd3tVGfLxAGrmQuwwyVsPQdEpGwB3E_bGE4Zbdw5Eya67psT55Ru81ggipsdLz1q7mHhNths64jCip1sXDvPCi_RBDeHWeza1RJmiuGVC9FfcWdVPLMLPZd2XM9pzu5ezA_FzA2O5g',
+                            fit: BoxFit.cover,
+                            errorBuilder: (context, _, __) => const Center(
+                              child: Icon(Icons.language, size: 64),
+                            ),
                           ),
                         ),
                       ),
-                    ),
+                    ],
 
                     SizedBox(height: gap(24, 10)),
                     Text(
@@ -215,17 +234,7 @@ class _LoginPageState extends State<LoginPage> {
                             : AppColors.surfaceDarkInput,
                       ),
                     ),
-                    SizedBox(height: gap(8, 4)),
-                    Text(
-                      'app.tagline'.tr(),
-                      textAlign: TextAlign.center,
-                      style: theme.textTheme.bodyMedium?.copyWith(
-                        color: isDark
-                            ? Colors.white70
-                            : AppColors.textSlateLight,
-                      ),
-                    ),
-                    SizedBox(height: gap(28, 14)),
+                    SizedBox(height: gap(24, 12)),
 
                     Text(
                       'auth.email'.tr(),
@@ -263,7 +272,9 @@ class _LoginPageState extends State<LoginPage> {
                         if (value == null || value.isEmpty) {
                           return 'auth.pleaseEnterEmail'.tr();
                         }
-                        if (!RegExp(r'^[^@\s]+@[^@\s]+\.[^@\s]+$').hasMatch(value.trim())) {
+                        if (!RegExp(
+                          r'^[^@\s]+@[^@\s]+\.[^@\s]+$',
+                        ).hasMatch(value.trim())) {
                           return 'auth.invalidEmail'.tr();
                         }
                         return null;
@@ -340,12 +351,14 @@ class _LoginPageState extends State<LoginPage> {
                             });
                           },
                         ),
-                        Text(
-                          'auth.rememberPassword'.tr(),
-                          style: theme.textTheme.bodyMedium?.copyWith(
-                            color: isDark
-                                ? Colors.white70
-                                : AppColors.surfaceDarkInput,
+                        Expanded(
+                          child: Text(
+                            'auth.rememberPassword'.tr(),
+                            style: theme.textTheme.bodyMedium?.copyWith(
+                              color: isDark
+                                  ? Colors.white70
+                                  : AppColors.surfaceDarkInput,
+                            ),
                           ),
                         ),
                       ],
@@ -363,6 +376,7 @@ class _LoginPageState extends State<LoginPage> {
                                   final messenger = ScaffoldMessenger.of(
                                     context,
                                   );
+                                  final navigator = Navigator.of(context);
                                   await authProvider.signInWithEmailPassword(
                                     _emailController.text.trim(),
                                     _passwordController.text,
@@ -373,6 +387,19 @@ class _LoginPageState extends State<LoginPage> {
                                   if (authProvider.isAuthenticated) {
                                     await _persistCredentialPreference();
                                     setState(() => _failedAttempts = 0);
+                                  } else if (_isEmailNotVerifiedMessage(
+                                    authProvider.errorMessage,
+                                  )) {
+                                    if (!mounted) return;
+                                    final email = _emailController.text.trim();
+                                    navigator.push(
+                                      MaterialPageRoute(
+                                        builder: (_) =>
+                                            EmailVerificationPendingPage(
+                                              email: email,
+                                            ),
+                                      ),
+                                    );
                                   } else if (_isInvalidCredentialMessage(
                                     authProvider.errorMessage,
                                   )) {
@@ -430,6 +457,16 @@ class _LoginPageState extends State<LoginPage> {
                           fontWeight: FontWeight.w600,
                         ),
                       ),
+                      const SizedBox(height: 4),
+                      Text(
+                        'If this account uses Google, tap Google below.',
+                        textAlign: TextAlign.center,
+                        style: theme.textTheme.bodySmall?.copyWith(
+                          color: isDark
+                              ? Colors.white70
+                              : AppColors.textSlateLight,
+                        ),
+                      ),
                     ],
 
                     if (_isLockedAfterFailures) ...[
@@ -503,7 +540,7 @@ class _LoginPageState extends State<LoginPage> {
                                       await authProvider.signInWithGoogle();
                                     },
                               icon: const Icon(Icons.g_mobiledata, size: 26),
-                              label: Text('auth.loginWithGoogle'.tr()),
+                              label: const Text('Google'),
                               style: OutlinedButton.styleFrom(
                                 shape: RoundedRectangleBorder(
                                   borderRadius: BorderRadius.circular(14),
@@ -523,7 +560,7 @@ class _LoginPageState extends State<LoginPage> {
                                       await authProvider.signInWithFacebook();
                                     },
                               icon: const Icon(Icons.facebook, size: 22),
-                              label: Text('auth.signInWithFacebook'.tr()),
+                              label: const Text('Facebook'),
                               style: OutlinedButton.styleFrom(
                                 shape: RoundedRectangleBorder(
                                   borderRadius: BorderRadius.circular(14),
@@ -536,8 +573,9 @@ class _LoginPageState extends State<LoginPage> {
                     ),
 
                     SizedBox(height: gap(24, 12)),
-                    Row(
-                      mainAxisAlignment: MainAxisAlignment.center,
+                    Wrap(
+                      alignment: WrapAlignment.center,
+                      crossAxisAlignment: WrapCrossAlignment.center,
                       children: [
                         Text(
                           'auth.dontHaveAccount'.tr(),
diff --git a/flutter-app/lib/features/auth/presentation/pages/onboarding_page.dart b/flutter-app/lib/features/auth/presentation/pages/onboarding_page.dart
index 79c9dbc5..b3352f67 100644
--- a/flutter-app/lib/features/auth/presentation/pages/onboarding_page.dart
+++ b/flutter-app/lib/features/auth/presentation/pages/onboarding_page.dart
@@ -77,155 +77,165 @@ class _OnboardingPageState extends State<OnboardingPage> {
           ? AppColors.accentMintDark
           : AppColors.backgroundLight,
       body: SafeArea(
-        child: Padding(
-          padding: const EdgeInsets.fromLTRB(20, 16, 20, 20),
-          child: Column(
-            children: [
-              Row(
+        child: Align(
+          alignment: Alignment.topCenter,
+          child: ConstrainedBox(
+            constraints: const BoxConstraints(maxWidth: 760),
+            child: Padding(
+              padding: const EdgeInsets.fromLTRB(20, 16, 20, 20),
+              child: Column(
                 children: [
-                  Text(
-                    'onboarding.personalizeTitle'.tr(),
-                    style: theme.textTheme.titleLarge?.copyWith(
-                      fontWeight: FontWeight.w700,
-                    ),
+                  Row(
+                    children: [
+                      Text(
+                        'onboarding.personalizeTitle'.tr(),
+                        style: theme.textTheme.titleLarge?.copyWith(
+                          fontWeight: FontWeight.w700,
+                        ),
+                      ),
+                      const Spacer(),
+                      Text(
+                        '${_currentPage + 1}/3',
+                        style: theme.textTheme.labelLarge?.copyWith(
+                          color: isDark ? Colors.white70 : AppColors.textSlate,
+                        ),
+                      ),
+                    ],
                   ),
-                  const Spacer(),
-                  Text(
-                    '${_currentPage + 1}/3',
-                    style: theme.textTheme.labelLarge?.copyWith(
-                      color: isDark ? Colors.white70 : AppColors.textSlate,
+                  const SizedBox(height: 12),
+                  ClipRRect(
+                    borderRadius: BorderRadius.circular(999),
+                    child: LinearProgressIndicator(
+                      value: (_currentPage + 1) / 3,
+                      minHeight: 8,
+                      backgroundColor: isDark
+                          ? AppColors.slate800
+                          : AppColors.slate200,
+                      valueColor: const AlwaysStoppedAnimation(
+                        AppColors.accentMint,
+                      ),
                     ),
                   ),
-                ],
-              ),
-              const SizedBox(height: 12),
-              ClipRRect(
-                borderRadius: BorderRadius.circular(999),
-                child: LinearProgressIndicator(
-                  value: (_currentPage + 1) / 3,
-                  minHeight: 8,
-                  backgroundColor: isDark
-                      ? AppColors.slate800
-                      : AppColors.slate200,
-                  valueColor: const AlwaysStoppedAnimation(
-                    AppColors.accentMint,
-                  ),
-                ),
-              ),
-              const SizedBox(height: 18),
-              Expanded(
-                child: PageView(
-                  controller: _pageController,
-                  physics: const NeverScrollableScrollPhysics(),
-                  onPageChanged: (index) {
-                    setState(() => _currentPage = index);
-                  },
-                  children: [
-                    _buildGoalGridStep(
-                      context: context,
-                      title: 'onboarding.goalQuestion'.tr(),
-                      subtitle: 'onboarding.goalSubtitle'.tr(),
-                      value: _selectedGoal,
-                      onSelected: (value) {
-                        setState(() => _selectedGoal = value);
+                  const SizedBox(height: 18),
+                  Expanded(
+                    child: PageView(
+                      controller: _pageController,
+                      physics: const NeverScrollableScrollPhysics(),
+                      onPageChanged: (index) {
+                        setState(() => _currentPage = index);
                       },
-                    ),
-                    _buildChoiceStep(
-                      context: context,
-                      title: 'onboarding.levelQuestion'.tr(),
-                      subtitle: 'onboarding.levelSubtitle'.tr(),
-                      value: _selectedLevel,
-                      options: [
-                        _OnboardingOption(
-                          'A1',
-                          'onboarding.levelA1'.tr(),
-                          Icons.child_care_rounded,
-                        ),
-                        _OnboardingOption(
-                          'A2',
-                          'onboarding.levelA2'.tr(),
-                          Icons.directions_walk_rounded,
-                        ),
-                        _OnboardingOption(
-                          'B1',
-                          'onboarding.levelB1'.tr(),
-                          Icons.directions_run_rounded,
+                      children: [
+                        _buildGoalGridStep(
+                          context: context,
+                          title: 'onboarding.goalQuestion'.tr(),
+                          subtitle: 'onboarding.goalSubtitle'.tr(),
+                          value: _selectedGoal,
+                          onSelected: (value) {
+                            setState(() => _selectedGoal = value);
+                          },
                         ),
-                        _OnboardingOption(
-                          'B2',
-                          'onboarding.levelB2'.tr(),
-                          Icons.directions_bike_rounded,
+                        _buildChoiceStep(
+                          context: context,
+                          title: 'onboarding.levelQuestion'.tr(),
+                          subtitle: 'onboarding.levelSubtitle'.tr(),
+                          value: _selectedLevel,
+                          options: [
+                            _OnboardingOption(
+                              'A1',
+                              'onboarding.levelA1'.tr(),
+                              Icons.child_care_rounded,
+                            ),
+                            _OnboardingOption(
+                              'A2',
+                              'onboarding.levelA2'.tr(),
+                              Icons.directions_walk_rounded,
+                            ),
+                            _OnboardingOption(
+                              'B1',
+                              'onboarding.levelB1'.tr(),
+                              Icons.directions_run_rounded,
+                            ),
+                            _OnboardingOption(
+                              'B2',
+                              'onboarding.levelB2'.tr(),
+                              Icons.directions_bike_rounded,
+                            ),
+                            _OnboardingOption(
+                              'C1',
+                              'onboarding.levelC1'.tr(),
+                              Icons.workspace_premium_rounded,
+                            ),
+                          ],
+                          onSelected: (value) {
+                            setState(() => _selectedLevel = value);
+                          },
                         ),
-                        _OnboardingOption(
-                          'C1',
-                          'onboarding.levelC1'.tr(),
-                          Icons.workspace_premium_rounded,
+                        _buildChoiceStep(
+                          context: context,
+                          title: 'onboarding.interestQuestion'.tr(),
+                          subtitle: 'onboarding.interestSubtitle'.tr(),
+                          value: _selectedInterest,
+                          options: [
+                            _OnboardingOption(
+                              'daily-life',
+                              'onboarding.interestDailyLife'.tr(),
+                              Icons.coffee_rounded,
+                            ),
+                            _OnboardingOption(
+                              'technology',
+                              'onboarding.interestTechnology'.tr(),
+                              Icons.computer_rounded,
+                            ),
+                            _OnboardingOption(
+                              'culture',
+                              'onboarding.interestCulture'.tr(),
+                              Icons.palette_rounded,
+                            ),
+                            _OnboardingOption(
+                              'career',
+                              'onboarding.interestCareer'.tr(),
+                              Icons.business_center_rounded,
+                            ),
+                          ],
+                          onSelected: (value) {
+                            setState(() => _selectedInterest = value);
+                          },
                         ),
                       ],
-                      onSelected: (value) {
-                        setState(() => _selectedLevel = value);
-                      },
                     ),
-                    _buildChoiceStep(
-                      context: context,
-                      title: 'onboarding.interestQuestion'.tr(),
-                      subtitle: 'onboarding.interestSubtitle'.tr(),
-                      value: _selectedInterest,
-                      options: [
-                        _OnboardingOption(
-                          'daily-life',
-                          'onboarding.interestDailyLife'.tr(),
-                          Icons.coffee_rounded,
-                        ),
-                        _OnboardingOption(
-                          'technology',
-                          'onboarding.interestTechnology'.tr(),
-                          Icons.computer_rounded,
-                        ),
-                        _OnboardingOption(
-                          'culture',
-                          'onboarding.interestCulture'.tr(),
-                          Icons.palette_rounded,
-                        ),
-                        _OnboardingOption(
-                          'career',
-                          'onboarding.interestCareer'.tr(),
-                          Icons.business_center_rounded,
+                  ),
+                  const SizedBox(height: 8),
+                  SizedBox(
+                    width: double.infinity,
+                    height: 54,
+                    child: ElevatedButton(
+                      onPressed: _isSubmitting ? null : _goNext,
+                      style: ElevatedButton.styleFrom(
+                        backgroundColor: AppColors.accentMint,
+                        foregroundColor: AppColors.accentMintDark,
+                        shape: RoundedRectangleBorder(
+                          borderRadius: BorderRadius.circular(14),
                         ),
-                      ],
-                      onSelected: (value) {
-                        setState(() => _selectedInterest = value);
-                      },
-                    ),
-                  ],
-                ),
-              ),
-              const SizedBox(height: 8),
-              SizedBox(
-                width: double.infinity,
-                height: 54,
-                child: ElevatedButton(
-                  onPressed: _isSubmitting ? null : _goNext,
-                  style: ElevatedButton.styleFrom(
-                    backgroundColor: AppColors.accentMint,
-                    foregroundColor: AppColors.accentMintDark,
-                    shape: RoundedRectangleBorder(
-                      borderRadius: BorderRadius.circular(14),
+                      ),
+                      child: _isSubmitting
+                          ? const SizedBox(
+                              width: 20,
+                              height: 20,
+                              child: LottieLoadingWidget.tiny(),
+                            )
+                          : Text(
+                              _currentPage < 2
+                                  ? 'onboarding.continueBtn'.tr()
+                                  : 'onboarding.createPlan'.tr(),
+                              style: const TextStyle(
+                                fontWeight: FontWeight.bold,
+                              ),
+                            ),
                     ),
                   ),
-                  child: _isSubmitting
-                      ? const SizedBox(
-                          width: 20,
-                          height: 20,
-                          child: LottieLoadingWidget.tiny(),
-                        )
-                      : Text(
-                          _currentPage < 2 ? 'onboarding.continueBtn'.tr() : 'onboarding.createPlan'.tr(),
-                          style: const TextStyle(fontWeight: FontWeight.bold),
-                        ),
-                ),
+                ],
               ),
-            ],
+            ),
           ),
         ),
       ),
diff --git a/flutter-app/lib/features/auth/presentation/pages/pre_auth_questions_page.dart b/flutter-app/lib/features/auth/presentation/pages/pre_auth_questions_page.dart
index b1849cb1..698b848b 100644
--- a/flutter-app/lib/features/auth/presentation/pages/pre_auth_questions_page.dart
+++ b/flutter-app/lib/features/auth/presentation/pages/pre_auth_questions_page.dart
@@ -133,115 +133,125 @@ class _PreAuthQuestionsPageState extends State<PreAuthQuestionsPage>
       body: FadeTransition(
         opacity: _fadeAnimation,
         child: SafeArea(
-          child: Padding(
-            padding: const EdgeInsets.fromLTRB(20, 16, 20, 20),
-            child: Column(
-              crossAxisAlignment: CrossAxisAlignment.stretch,
-              children: [
-                // Top bar
-                Row(
+          child: Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 680),
+              child: Padding(
+                padding: const EdgeInsets.fromLTRB(20, 16, 20, 20),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.stretch,
                   children: [
-                    IconButton(
-                      onPressed: _goBack,
-                      icon: Icon(
-                        Icons.arrow_back_rounded,
-                        color: isDark ? Colors.white : AppColors.textDark,
-                      ),
-                    ),
-                    Expanded(
-                      child: Text(
-                        'preAuth.quickSetup'.tr(),
-                        textAlign: TextAlign.center,
-                        style: theme.textTheme.titleMedium?.copyWith(
-                          fontWeight: FontWeight.w600,
-                          color: isDark ? Colors.white : AppColors.textDark,
+                    // Top bar
+                    Row(
+                      children: [
+                        IconButton(
+                          onPressed: _goBack,
+                          icon: Icon(
+                            Icons.arrow_back_rounded,
+                            color: isDark ? Colors.white : AppColors.textDark,
+                          ),
                         ),
-                      ),
+                        Expanded(
+                          child: Text(
+                            'preAuth.quickSetup'.tr(),
+                            textAlign: TextAlign.center,
+                            style: theme.textTheme.titleMedium?.copyWith(
+                              fontWeight: FontWeight.w600,
+                              color: isDark ? Colors.white : AppColors.textDark,
+                            ),
+                          ),
+                        ),
+                        Text(
+                          '${_currentPage + 1}/$_totalPages',
+                          style: theme.textTheme.labelLarge?.copyWith(
+                            color: isDark
+                                ? Colors.white60
+                                : AppColors.textSlate,
+                          ),
+                        ),
+                        const SizedBox(width: 6),
+                        const LanguageSwitcherButton(),
+                      ],
                     ),
-                    Text(
-                      '${_currentPage + 1}/$_totalPages',
-                      style: theme.textTheme.labelLarge?.copyWith(
-                        color: isDark ? Colors.white60 : AppColors.textSlate,
+                    const SizedBox(height: 10),
+                    // Progress bar
+                    ClipRRect(
+                      borderRadius: BorderRadius.circular(999),
+                      child: LinearProgressIndicator(
+                        value: (_currentPage + 1) / _totalPages,
+                        minHeight: 6,
+                        backgroundColor: isDark
+                            ? AppColors.slate800
+                            : AppColors.slate200,
+                        valueColor: const AlwaysStoppedAnimation(
+                          AppColors.accentMint,
+                        ),
                       ),
                     ),
-                    const SizedBox(width: 6),
-                    const LanguageSwitcherButton(),
-                  ],
-                ),
-                const SizedBox(height: 10),
-                // Progress bar
-                ClipRRect(
-                  borderRadius: BorderRadius.circular(999),
-                  child: LinearProgressIndicator(
-                    value: (_currentPage + 1) / _totalPages,
-                    minHeight: 6,
-                    backgroundColor: isDark
-                        ? AppColors.slate800
-                        : AppColors.slate200,
-                    valueColor: const AlwaysStoppedAnimation(
-                      AppColors.accentMint,
-                    ),
-                  ),
-                ),
-                const SizedBox(height: 20),
-                // Pages
-                Expanded(
-                  child: PageView(
-                    controller: _pageController,
-                    physics: const NeverScrollableScrollPhysics(),
-                    onPageChanged: (index) {
-                      setState(() => _currentPage = index);
-                    },
-                    children: [
-                      _buildNameStep(context, isDark, theme),
-                      _buildLanguageStep(context, isDark, theme),
-                    ],
-                  ),
-                ),
-                const SizedBox(height: 12),
-                // Continue button
-                SizedBox(
-                  width: double.infinity,
-                  height: 54,
-                  child: ElevatedButton(
-                    onPressed: _goNext,
-                    style: ElevatedButton.styleFrom(
-                      backgroundColor: AppColors.accentMint,
-                      foregroundColor: AppColors.accentMintDark,
-                      shape: RoundedRectangleBorder(
-                        borderRadius: BorderRadius.circular(14),
+                    const SizedBox(height: 20),
+                    // Pages
+                    Expanded(
+                      child: PageView(
+                        controller: _pageController,
+                        physics: const NeverScrollableScrollPhysics(),
+                        onPageChanged: (index) {
+                          setState(() => _currentPage = index);
+                        },
+                        children: [
+                          _buildNameStep(context, isDark, theme),
+                          _buildLanguageStep(context, isDark, theme),
+                        ],
                       ),
-                      elevation: 0,
                     ),
-                    child: Text(
-                      _currentPage < _totalPages - 1
-                          ? 'preAuth.continue'.tr()
-                          : 'preAuth.createMyAccount'.tr(),
-                      style: const TextStyle(
-                        fontWeight: FontWeight.bold,
-                        fontSize: 16,
+                    const SizedBox(height: 12),
+                    // Continue button
+                    SizedBox(
+                      width: double.infinity,
+                      height: 54,
+                      child: ElevatedButton(
+                        onPressed: _goNext,
+                        style: ElevatedButton.styleFrom(
+                          backgroundColor: AppColors.accentMint,
+                          foregroundColor: AppColors.accentMintDark,
+                          shape: RoundedRectangleBorder(
+                            borderRadius: BorderRadius.circular(14),
+                          ),
+                          elevation: 0,
+                        ),
+                        child: Text(
+                          _currentPage < _totalPages - 1
+                              ? 'preAuth.continue'.tr()
+                              : 'preAuth.createMyAccount'.tr(),
+                          style: const TextStyle(
+                            fontWeight: FontWeight.bold,
+                            fontSize: 16,
+                          ),
+                        ),
                       ),
                     ),
-                  ),
-                ),
-                if (_currentPage == _totalPages - 1) ...[
-                  const SizedBox(height: 10),
-                  SizedBox(
-                    width: double.infinity,
-                    height: 48,
-                    child: TextButton(
-                      onPressed: widget.onLogin,
-                      child: Text(
-                        'auth.alreadyHaveAccount'.tr(),
-                        style: TextStyle(
-                          color: isDark ? Colors.white60 : AppColors.textSlate,
-                          fontWeight: FontWeight.w500,
+                    if (_currentPage == _totalPages - 1) ...[
+                      const SizedBox(height: 10),
+                      SizedBox(
+                        width: double.infinity,
+                        height: 48,
+                        child: TextButton(
+                          onPressed: widget.onLogin,
+                          child: Text(
+                            'auth.alreadyHaveAccount'.tr(),
+                            style: TextStyle(
+                              color: isDark
+                                  ? Colors.white60
+                                  : AppColors.textSlate,
+                              fontWeight: FontWeight.w500,
+                            ),
+                          ),
                         ),
                       ),
-                    ),
-                  ),
-                ],
-              ],
+                    ],
+                  ],
+                ),
+              ),
             ),
           ),
         ),
diff --git a/flutter-app/lib/features/auth/presentation/pages/welcome_page.dart b/flutter-app/lib/features/auth/presentation/pages/welcome_page.dart
index cc9dcfbe..0c145d7e 100644
--- a/flutter-app/lib/features/auth/presentation/pages/welcome_page.dart
+++ b/flutter-app/lib/features/auth/presentation/pages/welcome_page.dart
@@ -87,7 +87,7 @@ class _WelcomePageState extends State<WelcomePage>
                         Expanded(
                           child: Center(
                             child: Image.asset(
-                              'assets/out-app/LexiLingo-logo.png',
+                              'assets/out-app/lexilingo-logo.png',
                               height: 40,
                               fit: BoxFit.contain,
                             ),
diff --git a/flutter-app/lib/features/auth/presentation/providers/auth_provider.dart b/flutter-app/lib/features/auth/presentation/providers/auth_provider.dart
index 6b6aa16d..172ba3b4 100644
--- a/flutter-app/lib/features/auth/presentation/providers/auth_provider.dart
+++ b/flutter-app/lib/features/auth/presentation/providers/auth_provider.dart
@@ -452,10 +452,10 @@ class AuthProvider extends ChangeNotifier {
           _user = null;
           _isJustLoggedIn = false;
         },
-        (user) {
-          _user = user;
+        (_) {
+          _user = null;
           _errorMessage = null;
-          _isJustLoggedIn = true;
+          _isJustLoggedIn = false;
         },
       );
     } catch (e) {
diff --git a/flutter-app/lib/features/books/data/repositories/book_repository.dart b/flutter-app/lib/features/books/data/repositories/book_repository.dart
index bf7fff98..7faee929 100644
--- a/flutter-app/lib/features/books/data/repositories/book_repository.dart
+++ b/flutter-app/lib/features/books/data/repositories/book_repository.dart
@@ -32,6 +32,15 @@ class BookRepository {
 
   String get _baseUrl => '${ApiConfig.baseUrl}/books';
 
+  String _stableFingerprint(String value) {
+    var hash = 0x811c9dc5;
+    for (final codeUnit in value.codeUnits.take(2000)) {
+      hash ^= codeUnit;
+      hash = (hash * 0x01000193) & 0xffffffff;
+    }
+    return hash.toRadixString(16).padLeft(8, '0');
+  }
+
   // ── Book Discovery ────────────────────────────────────────────
 
   /// Fetch curated books, optionally filtered by [cefrLevel].
@@ -136,16 +145,27 @@ class BookRepository {
   Future<BookQuiz> getChapterQuiz({
     required String bookId,
     required int chapter,
+    Book? book,
+    String? chapterExcerpt,
   }) async {
-    final cacheKey = 'books:quiz:$bookId:ch:$chapter';
+    final hasContext = chapterExcerpt?.trim().isNotEmpty == true;
+    final cacheKey = hasContext
+        ? 'books:quiz:$bookId:ch:$chapter:ctx:${_stableFingerprint(chapterExcerpt!.trim())}'
+        : 'books:quiz:$bookId:ch:$chapter';
 
     final data = await _cache.getOrFetch(
       key: cacheKey,
       type: 'book',
       fetchFn: () async {
+        final params = <String, String>{
+          'chapter': chapter.toString(),
+          if (book?.title.isNotEmpty == true) 'book_title': book!.title,
+          if (book?.cefrLevel.isNotEmpty == true) 'cefr_level': book!.cefrLevel,
+          if (hasContext) 'chapter_text': chapterExcerpt!.trim(),
+        };
         final uri = Uri.parse(
           '$_baseUrl/$bookId/quiz',
-        ).replace(queryParameters: {'chapter': chapter.toString()});
+        ).replace(queryParameters: params);
         final response = await _client.get(uri);
         if (response.statusCode != 200) {
           throw Exception('Quiz fetch failed: ${response.statusCode}');
diff --git a/flutter-app/lib/features/books/presentation/providers/book_provider.dart b/flutter-app/lib/features/books/presentation/providers/book_provider.dart
index 9f912875..9d30d516 100644
--- a/flutter-app/lib/features/books/presentation/providers/book_provider.dart
+++ b/flutter-app/lib/features/books/presentation/providers/book_provider.dart
@@ -2,6 +2,9 @@ import 'dart:async';
 
 import 'package:flutter/foundation.dart';
 
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+
 import '../../data/repositories/book_repository.dart';
 import '../../domain/entities/book_entities.dart';
 
@@ -10,9 +13,14 @@ import '../../domain/entities/book_entities.dart';
 /// Phase 5: Book Reading.
 class BookProvider extends ChangeNotifier {
   final BookRepository _repository;
+  final MistakeNotebookRepository _mistakeRepository;
 
-  BookProvider({BookRepository? repository})
-    : _repository = repository ?? BookRepository();
+  BookProvider({
+    BookRepository? repository,
+    MistakeNotebookRepository? mistakeRepository,
+  }) : _repository = repository ?? BookRepository(),
+       _mistakeRepository =
+           mistakeRepository ?? const MistakeNotebookRepository();
 
   // ── State ──────────────────────────────────────────────────
 
@@ -321,8 +329,9 @@ class BookProvider extends ChangeNotifier {
   }
 
   // Regex for Roman numerals (I–XXXIX range sufficient for chapters)
-  static final _romanNumeralRe =
-      RegExp(r'^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$');
+  static final _romanNumeralRe = RegExp(
+    r'^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$',
+  );
 
   /// Convert all-caps words (2+ letters) to title case.
   ///
@@ -346,15 +355,16 @@ class BookProvider extends ChangeNotifier {
       // Snap to a paragraph boundary (double newline) within ±200 chars of
       // the target end, but never before the current page start.
       if (end < text.length) {
-        final searchFrom =
-            (end - 200).clamp(offset + 1, text.length).toInt();
+        final searchFrom = (end - 200).clamp(offset + 1, text.length).toInt();
         final nextNewline = text.indexOf('\n\n', searchFrom);
         if (nextNewline != -1 && nextNewline <= end + 200) {
           end = nextNewline + 2;
         }
       }
       // Guard: ensure we always advance at least one character
-      if (end <= offset) end = (offset + charsPerPage).clamp(offset + 1, text.length);
+      if (end <= offset) {
+        end = (offset + charsPerPage).clamp(offset + 1, text.length);
+      }
       pages.add(text.substring(offset, end).trim());
       offset = end;
     }
@@ -470,6 +480,14 @@ class BookProvider extends ChangeNotifier {
 
   // ── Quiz ───────────────────────────────────────────────────
 
+  String? _quizExcerptForChapter(int chapter) {
+    if (_pages.isEmpty) return null;
+    final index = (chapter - 1).clamp(0, _pages.length - 1);
+    final excerpt = _pages[index].trim();
+    if (excerpt.isEmpty) return null;
+    return excerpt.length > 1800 ? excerpt.substring(0, 1800) : excerpt;
+  }
+
   Future<void> loadChapterQuiz(int chapter) async {
     final book = _currentBook;
     if (book == null) return;
@@ -485,6 +503,8 @@ class BookProvider extends ChangeNotifier {
       _currentQuiz = await _repository.getChapterQuiz(
         bookId: book.id,
         chapter: chapter,
+        book: book,
+        chapterExcerpt: _quizExcerptForChapter(chapter),
       );
     } catch (e) {
       _error = e.toString();
@@ -497,12 +517,52 @@ class BookProvider extends ChangeNotifier {
   void submitQuizAnswer(int questionIndex, int selectedIndex) {
     final quiz = _currentQuiz;
     if (quiz == null || questionIndex >= quiz.questions.length) return;
-    if (quiz.questions[questionIndex].correctIndex == selectedIndex) {
+    final question = quiz.questions[questionIndex];
+    if (question.correctIndex == selectedIndex) {
       _quizScore++;
+    } else {
+      unawaited(_saveQuizMistake(quiz, question, questionIndex, selectedIndex));
     }
     notifyListeners();
   }
 
+  Future<void> _saveQuizMistake(
+    BookQuiz quiz,
+    BookQuizQuestion question,
+    int questionIndex,
+    int selectedIndex,
+  ) async {
+    final selectedAnswer = _optionText(question.options, selectedIndex);
+    final correctAnswer = _optionText(question.options, question.correctIndex);
+
+    await _mistakeRepository.saveMistake(
+      MistakeNotebookEntry(
+        id: MistakeNotebookEntry.buildId(
+          sourceType: 'book_quiz',
+          sourceId: quiz.bookId,
+          questionId: question.id.isEmpty
+              ? '${quiz.chapter}:$questionIndex'
+              : question.id,
+          selectedAnswer: selectedAnswer,
+        ),
+        sourceType: 'book_quiz',
+        sourceId: quiz.bookId,
+        sourceTitle: _currentBook?.title ?? 'Book quiz',
+        question: question.question,
+        selectedAnswer: selectedAnswer,
+        correctAnswer: correctAnswer,
+        explanation: question.explanation,
+        skill: 'reading',
+        createdAt: DateTime.now(),
+      ),
+    );
+  }
+
+  String _optionText(List<String> options, int index) {
+    if (index < 0 || index >= options.length) return '';
+    return options[index];
+  }
+
   void completeQuiz() {
     _quizCompleted = true;
     notifyListeners();
diff --git a/flutter-app/lib/features/chat/data/models/educational_hints_model.dart b/flutter-app/lib/features/chat/data/models/educational_hints_model.dart
index e3afc36a..6e99d8d3 100644
--- a/flutter-app/lib/features/chat/data/models/educational_hints_model.dart
+++ b/flutter-app/lib/features/chat/data/models/educational_hints_model.dart
@@ -2,6 +2,8 @@
 /// Provides grammar corrections and vocabulary hints from AI responses
 library;
 
+import '../../domain/entities/educational_hints.dart' as entities;
+
 /// Grammar correction from AI
 class GrammarCorrection {
   final String original;
@@ -162,3 +164,45 @@ class LlmMetadata {
     'fallback_used': fallbackUsed,
   };
 }
+
+// ---------------------------------------------------------------------------
+// Domain entity mappers — see story_model.dart for rationale.
+// ---------------------------------------------------------------------------
+
+extension GrammarCorrectionToEntity on GrammarCorrection {
+  entities.GrammarCorrection toEntity() => entities.GrammarCorrection(
+    original: original,
+    corrected: corrected,
+    explanation: explanation,
+    errorType: errorType,
+    rule: rule,
+  );
+}
+
+extension VocabularyHintToEntity on VocabularyHint {
+  entities.VocabularyHint toEntity() => entities.VocabularyHint(
+    term: term,
+    definition: definition,
+    example: example,
+    partOfSpeech: partOfSpeech,
+    pronunciation: pronunciation,
+  );
+}
+
+extension EducationalHintsToEntity on EducationalHints {
+  entities.EducationalHints toEntity() => entities.EducationalHints(
+    grammarCorrections: grammarCorrections.map((g) => g.toEntity()).toList(),
+    vocabularyHints: vocabularyHints.map((v) => v.toEntity()).toList(),
+    encouragement: encouragement,
+    nextSuggestion: nextSuggestion,
+  );
+}
+
+extension LlmMetadataToEntity on LlmMetadata {
+  entities.LlmMetadata toEntity() => entities.LlmMetadata(
+    provider: provider,
+    model: model,
+    latencyMs: latencyMs,
+    fallbackUsed: fallbackUsed,
+  );
+}
diff --git a/flutter-app/lib/features/chat/data/models/story_model.dart b/flutter-app/lib/features/chat/data/models/story_model.dart
index 13aafe11..8a45bc57 100644
--- a/flutter-app/lib/features/chat/data/models/story_model.dart
+++ b/flutter-app/lib/features/chat/data/models/story_model.dart
@@ -3,31 +3,12 @@
 /// Defines story/topic data structures for language learning scenarios
 library;
 
-/// Difficulty levels matching CEFR standard
-enum DifficultyLevel {
-  A1('A1', 'Beginner'),
-  A2('A2', 'Elementary'),
-  B1('B1', 'Intermediate'),
-  B2('B2', 'Upper Intermediate'),
-  C1('C1', 'Advanced'),
-  C2('C2', 'Proficiency');
-
-  final String code;
-  final String label;
-
-  const DifficultyLevel(this.code, this.label);
-
-  String get displayName => '$code - $label';
-  String get shortName => code;
-
-  static DifficultyLevel fromString(String? value) {
-    if (value == null) return DifficultyLevel.A1;
-    return DifficultyLevel.values.firstWhere(
-      (e) => e.code.toUpperCase() == value.toUpperCase(),
-      orElse: () => DifficultyLevel.A1,
-    );
-  }
-}
+// DifficultyLevel is a domain concept owned by domain/entities/story.dart.
+// Re-exported here so existing callers of this model file keep working
+// without each needing to import the entity file directly.
+import '../../domain/entities/story.dart' show DifficultyLevel;
+export '../../domain/entities/story.dart' show DifficultyLevel;
+import '../../domain/entities/story.dart' as entities;
 
 /// Localized title with Vietnamese and English
 class LocalizedTitle {
@@ -458,3 +439,95 @@ class StoryListItem {
     'tags': tags,
   };
 }
+
+// ---------------------------------------------------------------------------
+// Domain entity mappers — convert wire-format models into the pure domain
+// entities defined in domain/entities/story.dart, used at the repository
+// boundary so domain/presentation never depend on these JSON-aware models.
+// ---------------------------------------------------------------------------
+
+extension LocalizedTitleToEntity on LocalizedTitle {
+  entities.LocalizedTitle toEntity() =>
+      entities.LocalizedTitle(vi: vi, en: en);
+}
+
+extension VocabularyItemToEntity on VocabularyItem {
+  entities.VocabularyItem toEntity() => entities.VocabularyItem(
+    term: term,
+    definition: definition,
+    exampleInStory: exampleInStory,
+    partOfSpeech: partOfSpeech,
+    phonetic: phonetic,
+  );
+}
+
+extension GrammarPointToEntity on GrammarPoint {
+  entities.GrammarPoint toEntity() => entities.GrammarPoint(
+    grammarStructure: grammarStructure,
+    explanation: explanation,
+    usageInStory: usageInStory,
+    examples: examples,
+  );
+}
+
+extension RolePersonaToEntity on RolePersona {
+  entities.RolePersona toEntity() => entities.RolePersona(
+    name: name,
+    role: role,
+    personality: personality,
+    speakingStyle: speakingStyle,
+    background: background,
+  );
+}
+
+extension ContextDescriptionToEntity on ContextDescription {
+  entities.ContextDescription toEntity() => entities.ContextDescription(
+    setting: setting,
+    scenario: scenario,
+    objectives: objectives,
+  );
+}
+
+extension ConversationFlowToEntity on ConversationFlow {
+  entities.ConversationFlow toEntity() => entities.ConversationFlow(
+    openingPrompt: openingPrompt,
+    keyMilestones: keyMilestones,
+    closingScenarios: closingScenarios,
+  );
+}
+
+extension StoryToEntity on Story {
+  entities.Story toEntity() => entities.Story(
+    storyId: storyId,
+    title: title.toEntity(),
+    difficultyLevel: difficultyLevel,
+    category: category,
+    estimatedMinutes: estimatedMinutes,
+    iconKey: iconKey,
+    coverImageUrl: coverImageUrl,
+    contextDescription: contextDescription.toEntity(),
+    rolePersona: rolePersona.toEntity(),
+    vocabularyList: vocabularyList.map((v) => v.toEntity()).toList(),
+    grammarPoints: grammarPoints.map((g) => g.toEntity()).toList(),
+    conversationFlow: conversationFlow.toEntity(),
+    isPublished: isPublished,
+    suggestedPrompts: suggestedPrompts,
+    tags: tags,
+    createdAt: createdAt,
+    updatedAt: updatedAt,
+  );
+}
+
+extension StoryListItemToEntity on StoryListItem {
+  entities.StoryListItem toEntity() => entities.StoryListItem(
+    storyId: storyId,
+    title: title.toEntity(),
+    difficultyLevel: difficultyLevel,
+    category: category,
+    estimatedMinutes: estimatedMinutes,
+    iconKey: iconKey,
+    coverImageUrl: coverImageUrl,
+    suggestedPrompts: suggestedPrompts,
+    tags: tags,
+  );
+}
diff --git a/flutter-app/lib/features/chat/data/models/topic_session_model.dart b/flutter-app/lib/features/chat/data/models/topic_session_model.dart
index fcc8040b..7994b755 100644
--- a/flutter-app/lib/features/chat/data/models/topic_session_model.dart
+++ b/flutter-app/lib/features/chat/data/models/topic_session_model.dart
@@ -4,6 +4,7 @@ library;
 
 import 'story_model.dart';
 import 'educational_hints_model.dart';
+import '../../domain/entities/topic_session.dart' as entities;
 
 /// Request to start a topic session
 class StartTopicSessionRequest {
@@ -288,3 +289,50 @@ class StoriesListResponse {
     'limit': limit,
   };
 }
+
+// ---------------------------------------------------------------------------
+// Domain entity mappers — see story_model.dart for rationale.
+// ---------------------------------------------------------------------------
+
+extension TopicSessionToEntity on TopicSession {
+  entities.TopicSession toEntity() => entities.TopicSession(
+    sessionId: sessionId,
+    story: story.toEntity(),
+    rolePersona: rolePersona.toEntity(),
+    openingMessage: openingMessage,
+    vocabularyPreview: vocabularyPreview.map((v) => v.toEntity()).toList(),
+    createdAt: createdAt,
+  );
+}
+
+extension TopicChatResponseToEntity on TopicChatResponse {
+  entities.TopicChatResponse toEntity() => entities.TopicChatResponse(
+    response: response,
+    messageIdOverride: messageId,
+    educationalHints: educationalHints?.toEntity(),
+    processingTimeMs: processingTimeMs,
+    llmMetadata: llmMetadata?.toEntity(),
+  );
+}
+
+extension TopicChatMessageToEntity on TopicChatMessage {
+  entities.TopicChatMessage toEntity() => entities.TopicChatMessage(
+    id: id,
+    sessionId: sessionId,
+    content: content,
+    isUser: isUser,
+    timestamp: timestamp,
+    hints: hints?.toEntity(),
+    llmMetadata: llmMetadata?.toEntity(),
+  );
+}
+
+extension TopicMessagesPageResultToEntity on TopicMessagesPageResult {
+  entities.TopicMessagesPageResult toEntity() =>
+      entities.TopicMessagesPageResult(
+        messages: messages.map((m) => m.toEntity()).toList(),
+        hasMore: hasMore,
+        nextCursor: nextCursor,
+        returned: returned,
+      );
+}
diff --git a/flutter-app/lib/features/chat/data/repositories/story_repository_impl.dart b/flutter-app/lib/features/chat/data/repositories/story_repository_impl.dart
index a17647d8..91c1df81 100644
--- a/flutter-app/lib/features/chat/data/repositories/story_repository_impl.dart
+++ b/flutter-app/lib/features/chat/data/repositories/story_repository_impl.dart
@@ -3,10 +3,25 @@ import 'package:dartz/dartz.dart';
 import '../../../../core/error/exceptions.dart';
 import '../../../../core/error/failures.dart';
 import '../../../../core/utils/app_logger.dart';
+import '../../domain/entities/story.dart';
+import '../../domain/entities/topic_session.dart';
 import '../../domain/repositories/story_repository.dart';
 import '../datasources/story_api_data_source.dart';
-import '../models/story_model.dart';
-import '../models/topic_session_model.dart';
+// Only the toEntity() extensions are needed here — the model classes
+// themselves would collide with the same-named domain entities above.
+import '../models/story_model.dart'
+    hide
+        Story,
+        StoryListItem,
+        DifficultyLevel,
+        LocalizedTitle,
+        VocabularyItem,
+        GrammarPoint,
+        RolePersona,
+        ContextDescription,
+        ConversationFlow;
+import '../models/topic_session_model.dart'
+    hide TopicSession, TopicChatResponse, TopicChatMessage, TopicMessagesPageResult;
 
 const _tag = 'StoryRepositoryImpl';
 
@@ -28,7 +43,7 @@ class StoryRepositoryImpl implements StoryRepository {
         difficultyLevel: difficultyLevel,
         limit: limit,
       );
-      return Right(stories);
+      return Right(stories.map((s) => s.toEntity()).toList());
     } on ServerException catch (e) {
       logError(_tag, 'getStories server error: $e');
       return Left(ServerFailure(e.message));
@@ -42,7 +57,7 @@ class StoryRepositoryImpl implements StoryRepository {
   Future<Either<Failure, Story>> getStoryDetails(String storyId) async {
     try {
       final story = await apiDataSource.getStoryDetails(storyId);
-      return Right(story);
+      return Right(story.toEntity());
     } on ServerException catch (e) {
       logError(_tag, 'getStoryDetails server error: $e');
       return Left(ServerFailure(e.message));
@@ -100,7 +115,7 @@ class StoryRepositoryImpl implements StoryRepository {
         sessionTitle: sessionTitle,
         preferredLlm: preferredLlm,
       );
-      return Right(session);
+      return Right(session.toEntity());
     } on ServerException catch (e) {
       logError(_tag, 'startTopicSession server error: $e');
       return Left(ServerFailure(e.message));
@@ -122,7 +137,7 @@ class StoryRepositoryImpl implements StoryRepository {
         userId: userId,
         message: message,
       );
-      return Right(response);
+      return Right(response.toEntity());
     } on ServerException catch (e) {
       logError(_tag, 'sendTopicMessage server error: $e');
       return Left(ServerFailure(e.message));
@@ -138,7 +153,7 @@ class StoryRepositoryImpl implements StoryRepository {
   ) async {
     try {
       final session = await apiDataSource.getTopicSession(sessionId);
-      return Right(session);
+      return Right(session.toEntity());
     } on ServerException catch (e) {
       logError(_tag, 'getTopicSession server error: $e');
       return Left(ServerFailure(e.message));
@@ -154,7 +169,7 @@ class StoryRepositoryImpl implements StoryRepository {
   ) async {
     try {
       final messages = await apiDataSource.getTopicMessages(sessionId);
-      return Right(messages);
+      return Right(messages.map((m) => m.toEntity()).toList());
     } on ServerException catch (e) {
       logError(_tag, 'getTopicMessages server error: $e');
       return Left(ServerFailure(e.message));
@@ -200,7 +215,7 @@ class StoryRepositoryImpl implements StoryRepository {
         limit: limit,
         cursor: cursor,
       );
-      return Right(page);
+      return Right(page.toEntity());
     } on ServerException catch (e) {
       logError(_tag, 'getTopicMessagesPaged server error: $e');
       return Left(ServerFailure(e.message));
diff --git a/flutter-app/lib/features/chat/domain/entities/educational_hints.dart b/flutter-app/lib/features/chat/domain/entities/educational_hints.dart
new file mode 100644
index 00000000..59c99297
--- /dev/null
+++ b/flutter-app/lib/features/chat/domain/entities/educational_hints.dart
@@ -0,0 +1,67 @@
+/// Domain entities for AI educational hints (grammar/vocabulary feedback).
+/// Pure Dart value objects — no JSON/serialization dependency.
+library;
+
+class GrammarCorrection {
+  final String original;
+  final String corrected;
+  final String explanation;
+  final String? errorType;
+  final String? rule;
+
+  const GrammarCorrection({
+    required this.original,
+    required this.corrected,
+    required this.explanation,
+    this.errorType,
+    this.rule,
+  });
+}
+
+class VocabularyHint {
+  final String term;
+  final String definition;
+  final String? example;
+  final String? partOfSpeech;
+  final String? pronunciation;
+
+  const VocabularyHint({
+    required this.term,
+    required this.definition,
+    this.example,
+    this.partOfSpeech,
+    this.pronunciation,
+  });
+}
+
+class EducationalHints {
+  final List<GrammarCorrection> grammarCorrections;
+  final List<VocabularyHint> vocabularyHints;
+  final String? encouragement;
+  final String? nextSuggestion;
+
+  const EducationalHints({
+    this.grammarCorrections = const [],
+    this.vocabularyHints = const [],
+    this.encouragement,
+    this.nextSuggestion,
+  });
+
+  bool get hasGrammarHints => grammarCorrections.isNotEmpty;
+  bool get hasVocabularyHints => vocabularyHints.isNotEmpty;
+  bool get hasAnyHints => hasGrammarHints || hasVocabularyHints;
+}
+
+class LlmMetadata {
+  final String provider;
+  final String model;
+  final int? latencyMs;
+  final bool fallbackUsed;
+
+  const LlmMetadata({
+    required this.provider,
+    required this.model,
+    this.latencyMs,
+    this.fallbackUsed = false,
+  });
+}
diff --git a/flutter-app/lib/features/chat/domain/entities/story.dart b/flutter-app/lib/features/chat/domain/entities/story.dart
new file mode 100644
index 00000000..374002d9
--- /dev/null
+++ b/flutter-app/lib/features/chat/domain/entities/story.dart
@@ -0,0 +1,215 @@
+// ignore_for_file: constant_identifier_names
+/// Domain entities for Story/Topic-based conversation.
+/// Pure Dart value objects — no JSON/serialization dependency, no data-layer imports.
+library;
+
+/// Difficulty levels matching CEFR standard
+enum DifficultyLevel {
+  A1('A1', 'Beginner'),
+  A2('A2', 'Elementary'),
+  B1('B1', 'Intermediate'),
+  B2('B2', 'Upper Intermediate'),
+  C1('C1', 'Advanced'),
+  C2('C2', 'Proficiency');
+
+  final String code;
+  final String label;
+
+  const DifficultyLevel(this.code, this.label);
+
+  String get displayName => '$code - $label';
+  String get shortName => code;
+
+  static DifficultyLevel fromString(String? value) {
+    if (value == null) return DifficultyLevel.A1;
+    return DifficultyLevel.values.firstWhere(
+      (e) => e.code.toUpperCase() == value.toUpperCase(),
+      orElse: () => DifficultyLevel.A1,
+    );
+  }
+}
+
+class LocalizedTitle {
+  final String vi;
+  final String en;
+
+  const LocalizedTitle({required this.vi, required this.en});
+}
+
+class VocabularyItem {
+  final String term;
+  final String definition;
+  final String exampleInStory;
+  final String partOfSpeech;
+  final String? phonetic;
+
+  const VocabularyItem({
+    required this.term,
+    required this.definition,
+    this.exampleInStory = '',
+    this.partOfSpeech = '',
+    this.phonetic,
+  });
+}
+
+class GrammarPoint {
+  final String grammarStructure;
+  final String explanation;
+  final String usageInStory;
+  final List<String> examples;
+
+  const GrammarPoint({
+    required this.grammarStructure,
+    required this.explanation,
+    this.usageInStory = '',
+    this.examples = const [],
+  });
+}
+
+class RolePersona {
+  final String name;
+  final String role;
+  final String personality;
+  final String speakingStyle;
+  final String background;
+
+  const RolePersona({
+    required this.name,
+    required this.role,
+    required this.personality,
+    required this.speakingStyle,
+    required this.background,
+  });
+}
+
+class ContextDescription {
+  final String setting;
+  final String scenario;
+  final List<String> objectives;
+
+  const ContextDescription({
+    required this.setting,
+    required this.scenario,
+    this.objectives = const [],
+  });
+}
+
+class ConversationFlow {
+  final String openingPrompt;
+  final List<String> keyMilestones;
+  final List<String> closingScenarios;
+
+  const ConversationFlow({
+    required this.openingPrompt,
+    this.keyMilestones = const [],
+    this.closingScenarios = const [],
+  });
+}
+
+/// Full story detail
+class Story {
+  final String storyId;
+  final LocalizedTitle title;
+  final DifficultyLevel difficultyLevel;
+  final String category;
+  final int estimatedMinutes;
+  final String? iconKey;
+  final String? coverImageUrl;
+  final ContextDescription contextDescription;
+  final RolePersona rolePersona;
+  final List<VocabularyItem> vocabularyList;
+  final List<GrammarPoint> grammarPoints;
+  final ConversationFlow conversationFlow;
+  final bool isPublished;
+  final List<String> suggestedPrompts;
+  final List<String> tags;
+  final DateTime? createdAt;
+  final DateTime? updatedAt;
+
+  const Story({
+    required this.storyId,
+    required this.title,
+    required this.difficultyLevel,
+    required this.category,
+    this.estimatedMinutes = 15,
+    this.iconKey,
+    this.coverImageUrl,
+    required this.contextDescription,
+    required this.rolePersona,
+    this.vocabularyList = const [],
+    this.grammarPoints = const [],
+    required this.conversationFlow,
+    this.isPublished = true,
+    this.suggestedPrompts = const [],
+    this.tags = const [],
+    this.createdAt,
+    this.updatedAt,
+  });
+}
+
+/// Story list item for display in story selection.
+///
+/// Carries its own [toCacheJson]/[fromCacheJson] pair purely for the
+/// presentation layer's local "recently used" persistence — this is the
+/// entity's own concern (how it survives a restart), not an API contract,
+/// so it doesn't pull in the data-layer model.
+class StoryListItem {
+  final String storyId;
+  final LocalizedTitle title;
+  final DifficultyLevel difficultyLevel;
+  final String category;
+  final int estimatedMinutes;
+  final String? iconKey;
+  final String? coverImageUrl;
+  final List<String> suggestedPrompts;
+  final List<String> tags;
+
+  const StoryListItem({
+    required this.storyId,
+    required this.title,
+    required this.difficultyLevel,
+    required this.category,
+    this.estimatedMinutes = 15,
+    this.iconKey,
+    this.coverImageUrl,
+    this.suggestedPrompts = const [],
+    this.tags = const [],
+  });
+
+  Map<String, dynamic> toCacheJson() => {
+    'story_id': storyId,
+    'title': {'vi': title.vi, 'en': title.en},
+    'category': category,
+    'difficulty_level': difficultyLevel.code,
+    'estimated_minutes': estimatedMinutes,
+    'icon_key': iconKey,
+    'cover_image_url': coverImageUrl,
+    'suggested_prompts': suggestedPrompts,
+    'tags': tags,
+  };
+
+  factory StoryListItem.fromCacheJson(Map<String, dynamic> json) {
+    return StoryListItem(
+      storyId: json['story_id'] as String? ?? '',
+      title: LocalizedTitle(
+        vi: (json['title'] as Map?)?['vi'] as String? ?? '',
+        en: (json['title'] as Map?)?['en'] as String? ?? '',
+      ),
+      category: json['category'] as String? ?? '',
+      difficultyLevel: DifficultyLevel.fromString(
+        json['difficulty_level'] as String?,
+      ),
+      estimatedMinutes: json['estimated_minutes'] as int? ?? 15,
+      iconKey: json['icon_key'] as String?,
+      coverImageUrl: json['cover_image_url'] as String?,
+      suggestedPrompts:
+          (json['suggested_prompts'] as List<dynamic>?)
+              ?.map((e) => e.toString())
+              .toList() ??
+          [],
+      tags:
+          (json['tags'] as List<dynamic>?)?.map((e) => e.toString()).toList() ??
+          [],
+    );
+  }
+}
diff --git a/flutter-app/lib/features/chat/domain/entities/topic_session.dart b/flutter-app/lib/features/chat/domain/entities/topic_session.dart
new file mode 100644
index 00000000..c96ec995
--- /dev/null
+++ b/flutter-app/lib/features/chat/domain/entities/topic_session.dart
@@ -0,0 +1,131 @@
+/// Domain entities for Topic-Based Conversation sessions.
+/// Pure Dart value objects — no JSON/serialization dependency, no data-layer imports.
+library;
+
+import 'story.dart';
+import 'educational_hints.dart';
+
+/// Response after starting a topic session
+class TopicSession {
+  final String sessionId;
+  final StoryListItem story;
+  final RolePersona rolePersona;
+  final String openingMessage;
+  final List<VocabularyItem> vocabularyPreview;
+  final DateTime createdAt;
+
+  const TopicSession({
+    required this.sessionId,
+    required this.story,
+    required this.rolePersona,
+    required this.openingMessage,
+    this.vocabularyPreview = const [],
+    required this.createdAt,
+  });
+
+  /// Local persistence only (the provider's "resume an active session"
+  /// cache) — not an API contract, so it lives on the entity itself rather
+  /// than pulling in the data-layer model.
+  Map<String, dynamic> toCacheJson() => {
+    'session_id': sessionId,
+    'story': story.toCacheJson(),
+    'role_persona': {
+      'name': rolePersona.name,
+      'role': rolePersona.role,
+      'personality': rolePersona.personality,
+      'speaking_style': rolePersona.speakingStyle,
+      'background': rolePersona.background,
+    },
+    'opening_message': openingMessage,
+    'created_at': createdAt.toIso8601String(),
+  };
+
+  factory TopicSession.fromCacheJson(Map<String, dynamic> json) {
+    final personaJson = json['role_persona'] as Map<String, dynamic>? ?? {};
+    return TopicSession(
+      sessionId: json['session_id'] as String? ?? '',
+      story: StoryListItem.fromCacheJson(
+        json['story'] as Map<String, dynamic>,
+      ),
+      rolePersona: RolePersona(
+        name: personaJson['name'] as String? ?? '',
+        role: personaJson['role'] as String? ?? '',
+        personality: personaJson['personality'] as String? ?? '',
+        speakingStyle: personaJson['speaking_style'] as String? ?? '',
+        background: personaJson['background'] as String? ?? '',
+      ),
+      openingMessage: json['opening_message'] as String? ?? '',
+      createdAt:
+          DateTime.tryParse(json['created_at']?.toString() ?? '') ??
+          DateTime.now(),
+    );
+  }
+}
+
+/// Response from AI in a topic session
+class TopicChatResponse {
+  final String response;
+  final String? messageIdOverride;
+  final EducationalHints? educationalHints;
+  final int? processingTimeMs;
+  final LlmMetadata? llmMetadata;
+
+  const TopicChatResponse({
+    required this.response,
+    this.messageIdOverride,
+    this.educationalHints,
+    this.processingTimeMs,
+    this.llmMetadata,
+  });
+
+  String get messageId =>
+      messageIdOverride ?? DateTime.now().millisecondsSinceEpoch.toString();
+  bool get hasHints => educationalHints?.hasAnyHints ?? false;
+}
+
+/// A message in the topic chat
+class TopicChatMessage {
+  final String id;
+  final String sessionId;
+  final String content;
+  final bool isUser;
+  final DateTime timestamp;
+  final EducationalHints? hints;
+  final LlmMetadata? llmMetadata;
+
+  const TopicChatMessage({
+    required this.id,
+    required this.sessionId,
+    required this.content,
+    required this.isUser,
+    required this.timestamp,
+    this.hints,
+    this.llmMetadata,
+  });
+
+  String get displayContent {
+    return content
+        .replaceAll(
+          RegExp(r'<think>[\s\S]*?</think>', caseSensitive: false),
+          '',
+        )
+        .trim();
+  }
+
+  bool get hasHints => hints?.hasAnyHints ?? false;
+}
+
+/// Cursor-based page result for topic chat messages.
+class TopicMessagesPageResult {
+  final List<TopicChatMessage> messages;
+  final bool hasMore;
+  final String? nextCursor;
+  final int returned;
+
+  const TopicMessagesPageResult({
+    required this.messages,
+    required this.hasMore,
+    required this.nextCursor,
+    required this.returned,
+  });
+}
diff --git a/flutter-app/lib/features/chat/domain/repositories/story_repository.dart b/flutter-app/lib/features/chat/domain/repositories/story_repository.dart
index 450a75d9..bdb2111a 100644
--- a/flutter-app/lib/features/chat/domain/repositories/story_repository.dart
+++ b/flutter-app/lib/features/chat/domain/repositories/story_repository.dart
@@ -1,8 +1,8 @@
 import 'package:dartz/dartz.dart';
 
 import '../../../../core/error/failures.dart';
-import '../../data/models/story_model.dart';
-import '../../data/models/topic_session_model.dart';
+import '../entities/story.dart';
+import '../entities/topic_session.dart';
 
 /// Repository interface for Story/Topic-based conversation
 abstract class StoryRepository {
diff --git a/flutter-app/lib/features/chat/presentation/pages/story_selection_page.dart b/flutter-app/lib/features/chat/presentation/pages/story_selection_page.dart
index 6b2e5b7a..fcfe76e1 100644
--- a/flutter-app/lib/features/chat/presentation/pages/story_selection_page.dart
+++ b/flutter-app/lib/features/chat/presentation/pages/story_selection_page.dart
@@ -4,7 +4,7 @@ import 'package:lexilingo_app/core/widgets/cefr_badge.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
-import '../../data/models/story_model.dart';
+import '../../domain/entities/story.dart';
 import '../providers/story_provider.dart';
 import '../utils/topic_icon_resolver.dart';
 import 'topic_chat_page.dart';
@@ -113,24 +113,30 @@ class _StorySelectionPageState extends State<StorySelectionPage> {
             return matchesSearch && matchesDifficulty;
           }).toList();
 
-          return Column(
-            children: [
-              // Search Bar
-              Padding(
-                padding: const EdgeInsets.all(16.0),
-                child: _buildSearchBar(theme, isDark),
-              ),
+          return Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 900),
+              child: Column(
+                children: [
+                  // Search Bar
+                  Padding(
+                    padding: const EdgeInsets.all(16.0),
+                    child: _buildSearchBar(theme, isDark),
+                  ),
 
-              // Filter Chips
-              _buildFilterChips(theme, isDark),
+                  // Filter Chips
+                  _buildFilterChips(theme, isDark),
 
-              // Content
-              Expanded(
-                child: provider.isLoading && provider.stories.isEmpty
-                    ? const Center(child: LottieLoadingWidget.medium())
-                    : _buildStoryList(filteredStories, theme, isDark),
+                  // Content
+                  Expanded(
+                    child: provider.isLoading && provider.stories.isEmpty
+                        ? const Center(child: LottieLoadingWidget.medium())
+                        : _buildStoryList(filteredStories, theme, isDark),
+                  ),
+                ],
               ),
-            ],
+            ),
           );
         },
       ),
@@ -487,5 +493,4 @@ class _TopicListItem extends StatelessWidget {
       ),
     );
   }
-
 }
diff --git a/flutter-app/lib/features/chat/presentation/pages/topic_chat_page.dart b/flutter-app/lib/features/chat/presentation/pages/topic_chat_page.dart
index fd51f9bb..d46304d6 100644
--- a/flutter-app/lib/features/chat/presentation/pages/topic_chat_page.dart
+++ b/flutter-app/lib/features/chat/presentation/pages/topic_chat_page.dart
@@ -8,8 +8,8 @@ import 'package:lexilingo_app/core/theme/app_theme.dart';
 
 import '../../../auth/presentation/providers/auth_provider.dart';
 import '../../../lexi_chat/presentation/widgets/lexi_typing_indicator.dart';
-import '../../data/models/story_model.dart';
-import '../../data/models/topic_session_model.dart';
+import '../../domain/entities/story.dart';
+import '../../domain/entities/topic_session.dart';
 import '../providers/story_provider.dart';
 import '../widgets/educational_hints_widgets.dart';
 
@@ -230,67 +230,73 @@ class _TopicChatPageState extends State<TopicChatPage> {
       appBar: _buildAppBar(isDark),
       body: Consumer<StoryProvider>(
         builder: (context, provider, child) {
-          return Column(
-            children: [
-              // 1. Story context header
-              if (provider.currentSession != null)
-                _StoryContextHeader(session: provider.currentSession!),
-
-              // 2. Messages list
-              Expanded(
-                child: provider.messages.isEmpty
-                    ? Center(
-                        child: Text(
-                          provider.isLoading
-                              ? 'topicChat.preparingTopicMessage'.tr()
-                              : 'topicChat.emptyStateMessage'.tr(),
-                          style: TextStyle(
-                            color: AppColorRoles.textMuted(isDark),
-                            fontStyle: FontStyle.italic,
+          return Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 980),
+              child: Column(
+                children: [
+                  // 1. Story context header
+                  if (provider.currentSession != null)
+                    _StoryContextHeader(session: provider.currentSession!),
+
+                  // 2. Messages list
+                  Expanded(
+                    child: provider.messages.isEmpty
+                        ? Center(
+                            child: Text(
+                              provider.isLoading
+                                  ? 'topicChat.preparingTopicMessage'.tr()
+                                  : 'topicChat.emptyStateMessage'.tr(),
+                              style: TextStyle(
+                                color: AppColorRoles.textMuted(isDark),
+                                fontStyle: FontStyle.italic,
+                              ),
+                            ),
+                          )
+                        : ListView.builder(
+                            controller: _scrollController,
+                            padding: const EdgeInsets.all(16),
+                            itemCount: provider.messages.length,
+                            itemBuilder: (context, index) {
+                              final message = provider.messages[index];
+                              return _TopicMessageBubble(message: message);
+                            },
                           ),
-                        ),
-                      )
-                    : ListView.builder(
-                        controller: _scrollController,
-                        padding: const EdgeInsets.all(16),
-                        itemCount: provider.messages.length,
-                        itemBuilder: (context, index) {
-                          final message = provider.messages[index];
-                          return _TopicMessageBubble(message: message);
-                        },
-                      ),
-              ),
+                  ),
 
-              // 3. Suggested Prompts (if any)
-              if (widget.story.suggestedPrompts.isNotEmpty &&
-                  !provider.isSendingMessage)
-                _buildSuggestedPrompts(isDark),
-
-              // 4. Typing indicator
-              if (provider.isSendingMessage)
-                LexiTypingIndicator(
-                  isThinking: true,
-                  name:
-                      provider.currentSession?.rolePersona.name
-                          .split(' ')
-                          .first ??
-                      'AI',
-                ),
+                  // 3. Suggested Prompts (if any)
+                  if (widget.story.suggestedPrompts.isNotEmpty &&
+                      !provider.isSendingMessage)
+                    _buildSuggestedPrompts(isDark),
+
+                  // 4. Typing indicator
+                  if (provider.isSendingMessage)
+                    LexiTypingIndicator(
+                      isThinking: true,
+                      name:
+                          provider.currentSession?.rolePersona.name
+                              .split(' ')
+                              .first ??
+                          'AI',
+                    ),
 
-              // 5. Task banner (collapses to zero height when hidden)
-              if (!_taskBannerDismissedByUser)
-                AnimatedSize(
-                  duration: const Duration(milliseconds: 260),
-                  curve: Curves.easeOutCubic,
-                  child: _taskBannerVisible
-                      ? _buildTaskBanner(isDark)
-                      : const SizedBox.shrink(),
-                ),
-              _buildInputField(
-                isEnabled: provider.hasActiveSession,
-                isDark: isDark,
+                  // 5. Task banner (collapses to zero height when hidden)
+                  if (!_taskBannerDismissedByUser)
+                    AnimatedSize(
+                      duration: const Duration(milliseconds: 260),
+                      curve: Curves.easeOutCubic,
+                      child: _taskBannerVisible
+                          ? _buildTaskBanner(isDark)
+                          : const SizedBox.shrink(),
+                    ),
+                  _buildInputField(
+                    isEnabled: provider.hasActiveSession,
+                    isDark: isDark,
+                  ),
+                ],
               ),
-            ],
+            ),
           );
         },
       ),
diff --git a/flutter-app/lib/features/chat/presentation/providers/story_provider.dart b/flutter-app/lib/features/chat/presentation/providers/story_provider.dart
index dd9e11f2..c1abda03 100644
--- a/flutter-app/lib/features/chat/presentation/providers/story_provider.dart
+++ b/flutter-app/lib/features/chat/presentation/providers/story_provider.dart
@@ -2,8 +2,8 @@ import 'package:flutter/foundation.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'dart:convert';
 
-import '../../data/models/story_model.dart';
-import '../../data/models/topic_session_model.dart';
+import '../../domain/entities/story.dart';
+import '../../domain/entities/topic_session.dart';
 import '../../domain/repositories/story_repository.dart';
 
 /// State management for Story/Topic-based conversation
@@ -485,7 +485,7 @@ class StoryProvider extends ChangeNotifier {
       final prefs = await SharedPreferences.getInstance();
       await prefs.setString(
         '$_topicSessionPrefix$storyId',
-        jsonEncode(session.toJson()),
+        jsonEncode(session.toCacheJson()),
       );
     } catch (e) {
       debugPrint('Error saving topic session: $e');
@@ -497,7 +497,9 @@ class StoryProvider extends ChangeNotifier {
       final prefs = await SharedPreferences.getInstance();
       final raw = prefs.getString('$_topicSessionPrefix$storyId');
       if (raw == null) return null;
-      return TopicSession.fromJson(jsonDecode(raw) as Map<String, dynamic>);
+      return TopicSession.fromCacheJson(
+        jsonDecode(raw) as Map<String, dynamic>,
+      );
     } catch (e) {
       debugPrint('Error loading saved topic session: $e');
       return null;
@@ -521,7 +523,7 @@ class StoryProvider extends ChangeNotifier {
 
       // Also cache full JSON for quick boot
       final jsonList = _recentlyUsed
-          .map((s) => jsonEncode(s.toJson()))
+          .map((s) => jsonEncode(s.toCacheJson()))
           .toList();
       await prefs.setStringList('${_recentTopicsKey}_data', jsonList);
     } catch (e) {
@@ -536,7 +538,11 @@ class StoryProvider extends ChangeNotifier {
 
       if (jsonList != null) {
         _recentlyUsed = jsonList
-            .map((s) => StoryListItem.fromJson(jsonDecode(s)))
+            .map(
+              (s) => StoryListItem.fromCacheJson(
+                jsonDecode(s) as Map<String, dynamic>,
+              ),
+            )
             .toList();
         notifyListeners();
       }
diff --git a/flutter-app/lib/features/chat/presentation/utils/topic_icon_resolver.dart b/flutter-app/lib/features/chat/presentation/utils/topic_icon_resolver.dart
index 42b47e55..846d4082 100644
--- a/flutter-app/lib/features/chat/presentation/utils/topic_icon_resolver.dart
+++ b/flutter-app/lib/features/chat/presentation/utils/topic_icon_resolver.dart
@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
 
-import '../../data/models/story_model.dart';
+import '../../domain/entities/story.dart';
 
 class TopicIconResolver {
   const TopicIconResolver._();
diff --git a/flutter-app/lib/features/chat/presentation/widgets/educational_hints_widgets.dart b/flutter-app/lib/features/chat/presentation/widgets/educational_hints_widgets.dart
index 8d121e0b..86324b23 100644
--- a/flutter-app/lib/features/chat/presentation/widgets/educational_hints_widgets.dart
+++ b/flutter-app/lib/features/chat/presentation/widgets/educational_hints_widgets.dart
@@ -1,7 +1,7 @@
 import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 
-import '../../data/models/educational_hints_model.dart';
+import '../../domain/entities/educational_hints.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
 
 /// Educational Hints Card
diff --git a/flutter-app/lib/features/chat/presentation/widgets/topic_card.dart b/flutter-app/lib/features/chat/presentation/widgets/topic_card.dart
index b88a4b90..73444a65 100644
--- a/flutter-app/lib/features/chat/presentation/widgets/topic_card.dart
+++ b/flutter-app/lib/features/chat/presentation/widgets/topic_card.dart
@@ -2,7 +2,7 @@ import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/widgets/cefr_badge.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
-import '../../data/models/story_model.dart';
+import '../../domain/entities/story.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
 import '../utils/topic_icon_resolver.dart';
 
diff --git a/flutter-app/lib/features/course/presentation/screens/category_detail_screen.dart b/flutter-app/lib/features/course/presentation/screens/category_detail_screen.dart
index 52c74a2a..49317b52 100644
--- a/flutter-app/lib/features/course/presentation/screens/category_detail_screen.dart
+++ b/flutter-app/lib/features/course/presentation/screens/category_detail_screen.dart
@@ -102,173 +102,180 @@ class _CategoryDetailScreenState extends State<CategoryDetailScreen> {
           // Use the courses loaded for this category
           final categoryCourses = provider.courses;
 
-          return CustomScrollView(
-            slivers: [
-              // App Bar with category info
-              SliverAppBar(
-                expandedHeight: 200,
-                pinned: true,
-                backgroundColor: categoryColor,
-                foregroundColor: Colors.white,
-                flexibleSpace: FlexibleSpaceBar(
-                  title: Text(
-                    category.name,
-                    style: TextStyle(
-                      color: Theme.of(context).colorScheme.surface,
-                      fontWeight: FontWeight.bold,
-                      shadows: [
-                        Shadow(
-                          color: Colors.black45,
-                          offset: Offset(0, 1),
-                          blurRadius: 4,
+          return Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 1180),
+              child: CustomScrollView(
+                slivers: [
+                  // App Bar with category info
+                  SliverAppBar(
+                    expandedHeight: 200,
+                    pinned: true,
+                    backgroundColor: categoryColor,
+                    foregroundColor: Colors.white,
+                    flexibleSpace: FlexibleSpaceBar(
+                      title: Text(
+                        category.name,
+                        style: TextStyle(
+                          color: Theme.of(context).colorScheme.surface,
+                          fontWeight: FontWeight.bold,
+                          shadows: [
+                            Shadow(
+                              color: Colors.black45,
+                              offset: Offset(0, 1),
+                              blurRadius: 4,
+                            ),
+                          ],
                         ),
-                      ],
+                      ),
+                      background: Container(
+                        decoration: BoxDecoration(
+                          gradient: LinearGradient(
+                            begin: Alignment.topLeft,
+                            end: Alignment.bottomRight,
+                            colors: [
+                              categoryColor,
+                              categoryColor.withValues(alpha: 0.7),
+                            ],
+                          ),
+                        ),
+                        child: Center(
+                          child: Icon(
+                            categoryIcon,
+                            size: 80,
+                            color: Theme.of(
+                              context,
+                            ).colorScheme.surface.withValues(alpha: 0.3),
+                          ),
+                        ),
+                      ),
                     ),
                   ),
-                  background: Container(
-                    decoration: BoxDecoration(
-                      gradient: LinearGradient(
-                        begin: Alignment.topLeft,
-                        end: Alignment.bottomRight,
-                        colors: [
-                          categoryColor,
-                          categoryColor.withValues(alpha: 0.7),
+
+                  // Course count info with view toggle and sort
+                  SliverToBoxAdapter(
+                    child: Padding(
+                      padding: const EdgeInsets.all(16.0),
+                      child: Row(
+                        children: [
+                          Expanded(
+                            child: Text(
+                              '${categoryCourses.length} ${categoryCourses.length == 1 ? 'course' : 'courses'} available',
+                              style: Theme.of(context).textTheme.titleMedium
+                                  ?.copyWith(
+                                    color: AppColorRoles.textSecondary(isDark),
+                                  ),
+                            ),
+                          ),
+                          // Sort dropdown
+                          PopupMenuButton<CourseSortOption>(
+                            icon: Row(
+                              mainAxisSize: MainAxisSize.min,
+                              children: [
+                                Icon(
+                                  _sortOption.icon,
+                                  size: 18,
+                                  color: AppColorRoles.textSecondary(isDark),
+                                ),
+                                const SizedBox(width: 4),
+                                Icon(
+                                  Icons.arrow_drop_down,
+                                  size: 18,
+                                  color: AppColorRoles.textSecondary(isDark),
+                                ),
+                              ],
+                            ),
+                            onSelected: (option) {
+                              setState(() => _sortOption = option);
+                            },
+                            itemBuilder: (context) =>
+                                CourseSortOption.values.map((option) {
+                                  return PopupMenuItem(
+                                    value: option,
+                                    child: Row(
+                                      children: [
+                                        Icon(option.icon, size: 18),
+                                        const SizedBox(width: 8),
+                                        Text(option.label),
+                                        if (option == _sortOption) ...[
+                                          const Spacer(),
+                                          const Icon(
+                                            Icons.check,
+                                            size: 18,
+                                            color: AppColors.greenSuccessBright,
+                                          ),
+                                        ],
+                                      ],
+                                    ),
+                                  );
+                                }).toList(),
+                          ),
+                          const SizedBox(width: 8),
+                          // View toggle
+                          IconButton(
+                            icon: Icon(
+                              _isGridView ? Icons.view_list : Icons.grid_view,
+                              color: AppColorRoles.textSecondary(isDark),
+                            ),
+                            onPressed: () {
+                              setState(() => _isGridView = !_isGridView);
+                            },
+                            tooltip: _isGridView ? 'List view' : 'Grid view',
+                          ),
                         ],
                       ),
                     ),
-                    child: Center(
-                      child: Icon(
-                        categoryIcon,
-                        size: 80,
-                        color: Theme.of(
-                          context,
-                        ).colorScheme.surface.withValues(alpha: 0.3),
-                      ),
-                    ),
                   ),
-                ),
-              ),
 
-              // Course count info with view toggle and sort
-              SliverToBoxAdapter(
-                child: Padding(
-                  padding: const EdgeInsets.all(16.0),
-                  child: Row(
-                    children: [
-                      Expanded(
-                        child: Text(
-                          '${categoryCourses.length} ${categoryCourses.length == 1 ? 'course' : 'courses'} available',
-                          style: Theme.of(context).textTheme.titleMedium
-                              ?.copyWith(
-                                color: AppColorRoles.textSecondary(isDark),
-                              ),
-                        ),
+                  // Course list
+                  if (provider.isLoadingCourses && categoryCourses.isEmpty)
+                    SliverFillRemaining(
+                      child: SkeletonList(
+                        itemCount: 5,
+                        padding: const EdgeInsets.all(16),
+                      ),
+                    )
+                  else if (provider.coursesError != null &&
+                      categoryCourses.isEmpty)
+                    SliverFillRemaining(
+                      child: ErrorDisplayWidget.fromMessage(
+                        message: provider.coursesError!,
+                        onRetry: () =>
+                            provider.loadCoursesByCategory(widget.categoryId),
                       ),
-                      // Sort dropdown
-                      PopupMenuButton<CourseSortOption>(
-                        icon: Row(
-                          mainAxisSize: MainAxisSize.min,
+                    )
+                  else if (categoryCourses.isEmpty)
+                    SliverFillRemaining(
+                      child: Center(
+                        child: Column(
+                          mainAxisAlignment: MainAxisAlignment.center,
                           children: [
                             Icon(
-                              _sortOption.icon,
-                              size: 18,
-                              color: AppColorRoles.textSecondary(isDark),
+                              Icons.folder_open,
+                              size: 64,
+                              color: AppColorRoles.textMuted(isDark),
                             ),
-                            const SizedBox(width: 4),
-                            Icon(
-                              Icons.arrow_drop_down,
-                              size: 18,
-                              color: AppColorRoles.textSecondary(isDark),
+                            const SizedBox(height: 16),
+                            Text(
+                              'course.noCourses'.tr(),
+                              style: Theme.of(context).textTheme.titleMedium
+                                  ?.copyWith(
+                                    color: AppColorRoles.textSecondary(isDark),
+                                  ),
                             ),
                           ],
                         ),
-                        onSelected: (option) {
-                          setState(() => _sortOption = option);
-                        },
-                        itemBuilder: (context) =>
-                            CourseSortOption.values.map((option) {
-                              return PopupMenuItem(
-                                value: option,
-                                child: Row(
-                                  children: [
-                                    Icon(option.icon, size: 18),
-                                    const SizedBox(width: 8),
-                                    Text(option.label),
-                                    if (option == _sortOption) ...[
-                                      const Spacer(),
-                                      const Icon(
-                                        Icons.check,
-                                        size: 18,
-                                        color: AppColors.greenSuccessBright,
-                                      ),
-                                    ],
-                                  ],
-                                ),
-                              );
-                            }).toList(),
                       ),
-                      const SizedBox(width: 8),
-                      // View toggle
-                      IconButton(
-                        icon: Icon(
-                          _isGridView ? Icons.view_list : Icons.grid_view,
-                          color: AppColorRoles.textSecondary(isDark),
-                        ),
-                        onPressed: () {
-                          setState(() => _isGridView = !_isGridView);
-                        },
-                        tooltip: _isGridView ? 'List view' : 'Grid view',
-                      ),
-                    ],
-                  ),
-                ),
+                    )
+                  else
+                    // Grid or List view with sorted courses and staggered animation
+                    _isGridView
+                        ? _buildCourseGrid(_sortCourses(categoryCourses))
+                        : _buildCourseList(_sortCourses(categoryCourses)),
+                ],
               ),
-
-              // Course list
-              if (provider.isLoadingCourses && categoryCourses.isEmpty)
-                SliverFillRemaining(
-                  child: SkeletonList(
-                    itemCount: 5,
-                    padding: const EdgeInsets.all(16),
-                  ),
-                )
-              else if (provider.coursesError != null && categoryCourses.isEmpty)
-                SliverFillRemaining(
-                  child: ErrorDisplayWidget.fromMessage(
-                    message: provider.coursesError!,
-                    onRetry: () =>
-                        provider.loadCoursesByCategory(widget.categoryId),
-                  ),
-                )
-              else if (categoryCourses.isEmpty)
-                SliverFillRemaining(
-                  child: Center(
-                    child: Column(
-                      mainAxisAlignment: MainAxisAlignment.center,
-                      children: [
-                        Icon(
-                          Icons.folder_open,
-                          size: 64,
-                          color: AppColorRoles.textMuted(isDark),
-                        ),
-                        const SizedBox(height: 16),
-                        Text(
-                          'course.noCourses'.tr(),
-                          style: Theme.of(context).textTheme.titleMedium
-                              ?.copyWith(
-                                color: AppColorRoles.textSecondary(isDark),
-                              ),
-                        ),
-                      ],
-                    ),
-                  ),
-                )
-              else
-                // Grid or List view with sorted courses and staggered animation
-                _isGridView
-                    ? _buildCourseGrid(_sortCourses(categoryCourses))
-                    : _buildCourseList(_sortCourses(categoryCourses)),
-            ],
+            ),
           );
         },
       ),
@@ -298,28 +305,39 @@ class _CategoryDetailScreenState extends State<CategoryDetailScreen> {
 
   /// Build grid view of courses
   Widget _buildCourseGrid(List<CourseEntity> courses) {
-    return SliverPadding(
-      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
-      sliver: SliverGrid(
-        gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
-          crossAxisCount: 2,
-          childAspectRatio: 0.75,
-          crossAxisSpacing: 12,
-          mainAxisSpacing: 12,
-        ),
-        delegate: SliverChildBuilderDelegate((context, index) {
-          final course = courses[index];
-          return AnimatedListItem(
-            index: index,
-            duration: const Duration(milliseconds: 300),
-            delayPerItem: const Duration(milliseconds: 50),
-            child: _CourseGridCard(
-              course: course,
-              onTap: () => _navigateToCourseDetail(context, course),
+    return SliverLayoutBuilder(
+      builder: (context, constraints) {
+        final width = constraints.crossAxisExtent;
+        final crossAxisCount = width >= 1000
+            ? 4
+            : width >= 680
+            ? 3
+            : 2;
+
+        return SliverPadding(
+          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+          sliver: SliverGrid(
+            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
+              crossAxisCount: crossAxisCount,
+              childAspectRatio: 0.75,
+              crossAxisSpacing: 12,
+              mainAxisSpacing: 12,
             ),
-          );
-        }, childCount: courses.length),
-      ),
+            delegate: SliverChildBuilderDelegate((context, index) {
+              final course = courses[index];
+              return AnimatedListItem(
+                index: index,
+                duration: const Duration(milliseconds: 300),
+                delayPerItem: const Duration(milliseconds: 50),
+                child: _CourseGridCard(
+                  course: course,
+                  onTap: () => _navigateToCourseDetail(context, course),
+                ),
+              );
+            }, childCount: courses.length),
+          ),
+        );
+      },
     );
   }
 
diff --git a/flutter-app/lib/features/course/presentation/screens/course_list_screen.dart b/flutter-app/lib/features/course/presentation/screens/course_list_screen.dart
index a77c255c..f7db5e47 100644
--- a/flutter-app/lib/features/course/presentation/screens/course_list_screen.dart
+++ b/flutter-app/lib/features/course/presentation/screens/course_list_screen.dart
@@ -56,137 +56,153 @@ class _CourseListScreenState extends State<CourseListScreen> {
     return Scaffold(
       body: Consumer<CourseProvider>(
         builder: (context, provider, child) {
-          return CustomScrollView(
-            controller: _scrollController,
-            slivers: [
-              // Modern SliverAppBar with gradient
-              SliverAppBar(
-                expandedHeight: 100,
-                floating: true,
-                pinned: true,
-                backgroundColor: Theme.of(context).scaffoldBackgroundColor,
-                automaticallyImplyLeading: false,
-                flexibleSpace: FlexibleSpaceBar(
-                  background: SafeArea(
-                    child: Padding(
-                      padding: const EdgeInsets.fromLTRB(20, 12, 20, 0),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        mainAxisAlignment: MainAxisAlignment.center,
-                        children: [
-                          Row(
+          return Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 1180),
+              child: CustomScrollView(
+                controller: _scrollController,
+                slivers: [
+                  // Modern SliverAppBar with gradient
+                  SliverAppBar(
+                    expandedHeight: 100,
+                    floating: true,
+                    pinned: true,
+                    backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+                    automaticallyImplyLeading: false,
+                    flexibleSpace: FlexibleSpaceBar(
+                      background: SafeArea(
+                        child: Padding(
+                          padding: const EdgeInsets.fromLTRB(20, 12, 20, 0),
+                          child: Column(
+                            crossAxisAlignment: CrossAxisAlignment.start,
+                            mainAxisAlignment: MainAxisAlignment.center,
                             children: [
-                              Container(
-                                padding: const EdgeInsets.all(10),
-                                decoration: BoxDecoration(
-                                  color: primaryAccent,
-                                  borderRadius: BorderRadius.circular(12),
-                                ),
-                                child: Icon(
-                                  Icons.explore,
-                                  color: Theme.of(context).colorScheme.surface,
-                                  size: 24,
-                                ),
-                              ),
-                              const SizedBox(width: 12),
-                              Column(
-                                crossAxisAlignment: CrossAxisAlignment.start,
-                                children: [
-                                  Text(
-                                    'course.discoverCourses'.tr(),
-                                    style: Theme.of(context)
-                                        .textTheme
-                                        .headlineSmall
-                                        ?.copyWith(fontWeight: FontWeight.bold),
-                                  ),
-                                  Text(
-                                    '${provider.courses.length} courses available',
-                                    style: Theme.of(context).textTheme.bodySmall
-                                        ?.copyWith(color: Colors.grey[600]),
-                                  ),
-                                ],
-                              ),
-                              const Spacer(),
-                              Stack(
+                              Row(
                                 children: [
                                   Container(
+                                    padding: const EdgeInsets.all(10),
                                     decoration: BoxDecoration(
-                                      color: provider.hasActiveFilters
-                                          ? primaryAccent
-                                          : primaryAccent.withValues(
-                                              alpha: 0.14),
+                                      color: primaryAccent,
                                       borderRadius: BorderRadius.circular(12),
                                     ),
-                                    child: IconButton(
-                                      icon: Icon(
-                                        Icons.tune_rounded,
-                                        color: provider.hasActiveFilters
-                                            ? Colors.white
-                                            : primaryAccent,
-                                      ),
-                                      onPressed: () =>
-                                          _showFilterSheet(context),
-                                      tooltip: 'Filter',
+                                    child: Icon(
+                                      Icons.explore,
+                                      color: Theme.of(
+                                        context,
+                                      ).colorScheme.surface,
+                                      size: 24,
                                     ),
                                   ),
-                                  if (provider.hasActiveFilters)
-                                    Positioned(
-                                      top: 6,
-                                      right: 6,
-                                      child: Container(
-                                        width: 8,
-                                        height: 8,
+                                  const SizedBox(width: 12),
+                                  Column(
+                                    crossAxisAlignment:
+                                        CrossAxisAlignment.start,
+                                    children: [
+                                      Text(
+                                        'course.discoverCourses'.tr(),
+                                        style: Theme.of(context)
+                                            .textTheme
+                                            .headlineSmall
+                                            ?.copyWith(
+                                              fontWeight: FontWeight.bold,
+                                            ),
+                                      ),
+                                      Text(
+                                        '${provider.courses.length} courses available',
+                                        style: Theme.of(context)
+                                            .textTheme
+                                            .bodySmall
+                                            ?.copyWith(color: Colors.grey[600]),
+                                      ),
+                                    ],
+                                  ),
+                                  const Spacer(),
+                                  Stack(
+                                    children: [
+                                      Container(
                                         decoration: BoxDecoration(
-                                          color: Colors.amber,
-                                          shape: BoxShape.circle,
-                                          border: Border.all(
-                                            color: Theme.of(context)
-                                                .scaffoldBackgroundColor,
-                                            width: 1.5,
+                                          color: provider.hasActiveFilters
+                                              ? primaryAccent
+                                              : primaryAccent.withValues(
+                                                  alpha: 0.14,
+                                                ),
+                                          borderRadius: BorderRadius.circular(
+                                            12,
                                           ),
                                         ),
+                                        child: IconButton(
+                                          icon: Icon(
+                                            Icons.tune_rounded,
+                                            color: provider.hasActiveFilters
+                                                ? Colors.white
+                                                : primaryAccent,
+                                          ),
+                                          onPressed: () =>
+                                              _showFilterSheet(context),
+                                          tooltip: 'Filter',
+                                        ),
                                       ),
-                                    ),
+                                      if (provider.hasActiveFilters)
+                                        Positioned(
+                                          top: 6,
+                                          right: 6,
+                                          child: Container(
+                                            width: 8,
+                                            height: 8,
+                                            decoration: BoxDecoration(
+                                              color: Colors.amber,
+                                              shape: BoxShape.circle,
+                                              border: Border.all(
+                                                color: Theme.of(
+                                                  context,
+                                                ).scaffoldBackgroundColor,
+                                                width: 1.5,
+                                              ),
+                                            ),
+                                          ),
+                                        ),
+                                    ],
+                                  ),
                                 ],
                               ),
                             ],
                           ),
-                        ],
+                        ),
                       ),
                     ),
+                    actions: const [],
                   ),
-                ),
-                actions: const [],
-              ),
-
-              // Hero banner below heading
-              const SliverToBoxAdapter(child: _CourseBanner()),
 
-              // Content
-              if ((provider.isLoadingCourses || provider.isLoadingCategories) &&
-                  provider.courses.isEmpty &&
-                  provider.categories.isEmpty)
-                const SliverFillRemaining(
-                  child: Center(child: LottieLoadingWidget.medium()),
-                )
-              else if (provider.coursesError != null &&
-                  provider.courses.isEmpty)
-                SliverFillRemaining(
-                  child: ErrorDisplayWidget.fromMessage(
-                    message: provider.coursesError!,
-                    onRetry: () {
-                      provider.refreshCourses();
-                      provider.loadCategories();
-                    },
-                  ),
-                )
-              else if (provider.courses.isEmpty)
-                SliverFillRemaining(
-                  child: EmptyStateWidget.courses(),
-                )
-              else
-                _buildCourseContent(context, provider),
-            ],
+                  // Hero banner below heading
+                  const SliverToBoxAdapter(child: _CourseBanner()),
+
+                  // Content
+                  if ((provider.isLoadingCourses ||
+                          provider.isLoadingCategories) &&
+                      provider.courses.isEmpty &&
+                      provider.categories.isEmpty)
+                    const SliverFillRemaining(
+                      child: Center(child: LottieLoadingWidget.medium()),
+                    )
+                  else if (provider.coursesError != null &&
+                      provider.courses.isEmpty)
+                    SliverFillRemaining(
+                      child: ErrorDisplayWidget.fromMessage(
+                        message: provider.coursesError!,
+                        onRetry: () {
+                          provider.refreshCourses();
+                          provider.loadCategories();
+                        },
+                      ),
+                    )
+                  else if (provider.courses.isEmpty)
+                    SliverFillRemaining(child: EmptyStateWidget.courses())
+                  else
+                    _buildCourseContent(context, provider),
+                ],
+              ),
+            ),
           );
         },
       ),
@@ -199,9 +215,7 @@ class _CourseListScreenState extends State<CourseListScreen> {
 
     // Show empty-filtered state when client-side filters result in nothing
     if (displayCourses.isEmpty) {
-      return SliverFillRemaining(
-        child: EmptyStateWidget.searchResults(),
-      );
+      return SliverFillRemaining(child: EmptyStateWidget.searchResults());
     }
 
     final categories = provider.categories;
@@ -249,64 +263,66 @@ class _CourseListScreenState extends State<CourseListScreen> {
       final levelKeys = grouped.keys.toList();
 
       return SliverList(
-        delegate: SliverChildBuilderDelegate(
-          (context, index) {
-            if (index == levelKeys.length) {
-              return const Center(
-                child: Padding(
-                  padding: EdgeInsets.all(16.0),
-                  child: LottieLoadingWidget.small(),
-                ),
-              );
-            }
-            final levelKey = levelKeys[index];
-            final courses = grouped[levelKey]!;
-            return _CategorySection(
-              categoryId: levelKey,
-              title: levelKey,
-              description:
-                  '${courses.length} ${courses.length == 1 ? 'course' : 'courses'}',
-              icon: _getLevelIcon(levelKey),
-              color: _getLevelColor(levelKey, isDark: isDark),
-              courses: courses,
-              onCourseTap: (course, fallbackThumbnailUrl) =>
-                  _navigateToCourseDetail(context, course, fallbackThumbnailUrl),
-              onSeeAll: null,
+        delegate: SliverChildBuilderDelegate((context, index) {
+          if (index == levelKeys.length) {
+            return const Center(
+              child: Padding(
+                padding: EdgeInsets.all(16.0),
+                child: LottieLoadingWidget.small(),
+              ),
             );
-          },
-          childCount: levelKeys.length + (provider.isLoadingCourses ? 1 : 0),
-        ),
+          }
+          final levelKey = levelKeys[index];
+          final courses = grouped[levelKey]!;
+          return _CategorySection(
+            categoryId: levelKey,
+            title: levelKey,
+            description:
+                '${courses.length} ${courses.length == 1 ? 'course' : 'courses'}',
+            icon: _getLevelIcon(levelKey),
+            color: _getLevelColor(levelKey, isDark: isDark),
+            courses: courses,
+            onCourseTap: (course, fallbackThumbnailUrl) =>
+                _navigateToCourseDetail(context, course, fallbackThumbnailUrl),
+            onSeeAll: null,
+          );
+        }, childCount: levelKeys.length + (provider.isLoadingCourses ? 1 : 0)),
       );
     }
 
     return SliverList(
-      delegate: SliverChildBuilderDelegate((context, index) {
-        if (index == nonEmptyCategorySections.length) {
-          return const Center(
-            child: Padding(
-              padding: EdgeInsets.all(16.0),
-              child: LottieLoadingWidget.small(),
-            ),
+      delegate: SliverChildBuilderDelegate(
+        (context, index) {
+          if (index == nonEmptyCategorySections.length) {
+            return const Center(
+              child: Padding(
+                padding: EdgeInsets.all(16.0),
+                child: LottieLoadingWidget.small(),
+              ),
+            );
+          }
+
+          final section = nonEmptyCategorySections[index];
+          final category = section.key;
+          final categoryCourses = section.value;
+
+          return _CategorySection(
+            categoryId: category.id,
+            title: category.name,
+            description:
+                '${categoryCourses.length} ${categoryCourses.length == 1 ? 'course' : 'courses'}',
+            icon: _parseCategoryIcon(category.icon ?? 'book'),
+            color: _parseCategoryColor(category.color, isDark: isDark),
+            courses: categoryCourses,
+            onCourseTap: (course, fallbackThumbnailUrl) =>
+                _navigateToCourseDetail(context, course, fallbackThumbnailUrl),
+            onSeeAll: () => _navigateToCategoryDetail(context, category.id),
           );
-        }
-
-        final section = nonEmptyCategorySections[index];
-        final category = section.key;
-        final categoryCourses = section.value;
-
-        return _CategorySection(
-          categoryId: category.id,
-          title: category.name,
-          description:
-              '${categoryCourses.length} ${categoryCourses.length == 1 ? 'course' : 'courses'}',
-          icon: _parseCategoryIcon(category.icon ?? 'book'),
-          color: _parseCategoryColor(category.color, isDark: isDark),
-          courses: categoryCourses,
-          onCourseTap: (course, fallbackThumbnailUrl) =>
-              _navigateToCourseDetail(context, course, fallbackThumbnailUrl),
-          onSeeAll: () => _navigateToCategoryDetail(context, category.id),
-        );
-      }, childCount: nonEmptyCategorySections.length + (provider.isLoadingCourses ? 1 : 0)),
+        },
+        childCount:
+            nonEmptyCategorySections.length +
+            (provider.isLoadingCourses ? 1 : 0),
+      ),
     );
   }
 
@@ -948,7 +964,7 @@ class _HorizontalCourseCard extends StatelessWidget {
     ];
     const business = [
       'https://images.unsplash.com/photo-1486406146926-c627a92ad1ab?w=800&q=80', // glass office buildings
-      'https://images.unsplash.com/photo-1554224155-6726b3ff858f?w=800&q=80',    // financial charts
+      'https://images.unsplash.com/photo-1554224155-6726b3ff858f?w=800&q=80', // financial charts
       'https://images.unsplash.com/photo-1486312338219-ce68d2c6f44d?w=800&q=80', // laptop workspace
     ];
     const conversation = [
@@ -992,7 +1008,7 @@ class _HorizontalCourseCard extends StatelessWidget {
       'https://images.unsplash.com/photo-1512820790803-83ca734da794?w=800&q=80', // colorful books
     ];
     const intermediate = [
-      'https://images.unsplash.com/photo-1546410531-bb4caa6b424d?w=800&q=80',    // open book pages
+      'https://images.unsplash.com/photo-1546410531-bb4caa6b424d?w=800&q=80', // open book pages
       'https://images.unsplash.com/photo-1499750310107-5fef28a66643?w=800&q=80', // laptop on desk
       'https://images.unsplash.com/photo-1544716278-ca5e3f4abd8c?w=800&q=80', // coffee on book
     ];
@@ -1002,7 +1018,9 @@ class _HorizontalCourseCard extends StatelessWidget {
       'https://images.unsplash.com/photo-1486406146926-c627a92ad1ab?w=800&q=80', // office buildings
     ];
 
-    if (tags.contains('ielts') || tags.contains('test-prep') || tags.contains('exam')) {
+    if (tags.contains('ielts') ||
+        tags.contains('test-prep') ||
+        tags.contains('exam')) {
       return ielts[pick % ielts.length];
     }
     if (tags.contains('business') || tags.contains('business-english')) {
@@ -1412,7 +1430,6 @@ class _FilterSheetState extends State<_FilterSheet> {
     _sortOrder = p.sortOrder;
   }
 
-
   bool get _hasAnyFilter =>
       _language != null ||
       _level != null ||
@@ -1423,7 +1440,8 @@ class _FilterSheetState extends State<_FilterSheet> {
   Future<void> _applyFilters() async {
     final provider = context.read<CourseProvider>();
     final serverParamsChanged =
-        _language != provider.selectedLanguage || _level != provider.selectedLevel;
+        _language != provider.selectedLanguage ||
+        _level != provider.selectedLevel;
 
     // Apply client-side filters first (instant)
     provider.setClientFilters(
@@ -1466,8 +1484,7 @@ class _FilterSheetState extends State<_FilterSheet> {
         return Container(
           decoration: BoxDecoration(
             color: Theme.of(context).colorScheme.surface,
-            borderRadius:
-                const BorderRadius.vertical(top: Radius.circular(24)),
+            borderRadius: const BorderRadius.vertical(top: Radius.circular(24)),
           ),
           child: Column(
             children: [
@@ -1516,7 +1533,8 @@ class _FilterSheetState extends State<_FilterSheet> {
                             icon: const Icon(Icons.clear_all, size: 18),
                             label: Text('common.clear'.tr()),
                             style: TextButton.styleFrom(
-                                foregroundColor: Colors.red[400]),
+                              foregroundColor: Colors.red[400],
+                            ),
                           ),
                       ],
                     ),
@@ -1554,7 +1572,10 @@ class _FilterSheetState extends State<_FilterSheet> {
                           isSelected: _language == 'English',
                           color: primaryAccent,
                           prefix: _LangBadge(
-                              'EN', primaryAccent, _language == 'English'),
+                            'EN',
+                            primaryAccent,
+                            _language == 'English',
+                          ),
                           onTap: () => setState(() => _language = 'English'),
                         ),
                         _Chip(
@@ -1562,17 +1583,22 @@ class _FilterSheetState extends State<_FilterSheet> {
                           isSelected: _language == 'Spanish',
                           color: AppColors.orange,
                           prefix: _LangBadge(
-                              'ES', AppColors.orange, _language == 'Spanish'),
+                            'ES',
+                            AppColors.orange,
+                            _language == 'Spanish',
+                          ),
                           onTap: () => setState(() => _language = 'Spanish'),
                         ),
                         _Chip(
                           label: 'Vietnamese',
                           isSelected: _language == 'Vietnamese',
                           color: AppColors.errorBright,
-                          prefix: _LangBadge('VI', AppColors.errorBright,
-                              _language == 'Vietnamese'),
-                          onTap: () =>
-                              setState(() => _language = 'Vietnamese'),
+                          prefix: _LangBadge(
+                            'VI',
+                            AppColors.errorBright,
+                            _language == 'Vietnamese',
+                          ),
+                          onTap: () => setState(() => _language = 'Vietnamese'),
                         ),
                       ],
                     ),
@@ -1625,11 +1651,14 @@ class _FilterSheetState extends State<_FilterSheet> {
                               label: cat.name,
                               isSelected: _categorySlug == cat.slug,
                               color: _parseCategoryColor(
-                                  cat.color, isDark: isDark),
+                                cat.color,
+                                isDark: isDark,
+                              ),
                               onTap: () => setState(
-                                  () => _categorySlug = _categorySlug == cat.slug
-                                      ? null
-                                      : cat.slug),
+                                () => _categorySlug = _categorySlug == cat.slug
+                                    ? null
+                                    : cat.slug,
+                              ),
                             ),
                           ),
                         ],
@@ -1651,7 +1680,9 @@ class _FilterSheetState extends State<_FilterSheet> {
                       child: AnimatedContainer(
                         duration: const Duration(milliseconds: 200),
                         padding: const EdgeInsets.symmetric(
-                            horizontal: 16, vertical: 12),
+                          horizontal: 16,
+                          vertical: 12,
+                        ),
                         decoration: BoxDecoration(
                           color: _enrolledOnly
                               ? Colors.amber[700]!.withValues(alpha: 0.12)
@@ -1681,8 +1712,8 @@ class _FilterSheetState extends State<_FilterSheet> {
                                 color: _enrolledOnly
                                     ? Colors.amber[700]
                                     : (isDark
-                                        ? Colors.white70
-                                        : Colors.black87),
+                                          ? Colors.white70
+                                          : Colors.black87),
                               ),
                             ),
                             const Spacer(),
@@ -1691,8 +1722,9 @@ class _FilterSheetState extends State<_FilterSheet> {
                               onChanged: (v) =>
                                   setState(() => _enrolledOnly = v),
                               activeThumbColor: Colors.amber[700],
-                              activeTrackColor:
-                                  Colors.amber[700]!.withValues(alpha: 0.4),
+                              activeTrackColor: Colors.amber[700]!.withValues(
+                                alpha: 0.4,
+                              ),
                             ),
                           ],
                         ),
@@ -1738,12 +1770,17 @@ class _FilterSheetState extends State<_FilterSheet> {
               // Apply button (fixed at bottom)
               Container(
                 padding: EdgeInsets.fromLTRB(
-                    20, 12, 20, 12 + MediaQuery.of(context).padding.bottom),
+                  20,
+                  12,
+                  20,
+                  12 + MediaQuery.of(context).padding.bottom,
+                ),
                 decoration: BoxDecoration(
                   color: Theme.of(context).colorScheme.surface,
                   border: Border(
                     top: BorderSide(
-                        color: isDark ? Colors.white12 : Colors.black12),
+                      color: isDark ? Colors.white12 : Colors.black12,
+                    ),
                   ),
                 ),
                 child: SizedBox(
@@ -1754,12 +1791,15 @@ class _FilterSheetState extends State<_FilterSheet> {
                     style: FilledButton.styleFrom(
                       backgroundColor: primaryAccent,
                       shape: RoundedRectangleBorder(
-                          borderRadius: BorderRadius.circular(14)),
+                        borderRadius: BorderRadius.circular(14),
+                      ),
                     ),
                     child: const Text(
                       'Apply Filters',
                       style: TextStyle(
-                          fontWeight: FontWeight.bold, fontSize: 15),
+                        fontWeight: FontWeight.bold,
+                        fontSize: 15,
+                      ),
                     ),
                   ),
                 ),
diff --git a/flutter-app/lib/features/games/domain/entities/game_entities.dart b/flutter-app/lib/features/games/domain/entities/game_entities.dart
index c008bfaa..2c07e197 100644
--- a/flutter-app/lib/features/games/domain/entities/game_entities.dart
+++ b/flutter-app/lib/features/games/domain/entities/game_entities.dart
@@ -166,6 +166,7 @@ class ScrambleWord {
   final int xpValue;
   final int letterCount;
   final String cefrLevel;
+  final String? vietnameseTranslation;
 
   const ScrambleWord({
     required this.wordId,
@@ -178,6 +179,7 @@ class ScrambleWord {
     this.xpValue = 10,
     this.letterCount = 0,
     this.cefrLevel = 'A1',
+    this.vietnameseTranslation,
   });
 
   factory ScrambleWord.fromJson(Map<String, dynamic> json) {
@@ -203,6 +205,7 @@ class ScrambleWord {
       xpValue: json['xp_value'] as int? ?? 10,
       letterCount: json['letter_count'] as int? ?? word.length,
       cefrLevel: json['cefr_level'] as String? ?? 'A1',
+      vietnameseTranslation: json['vietnamese_translation'] as String?,
     );
   }
 
@@ -217,6 +220,8 @@ class ScrambleWord {
     'xp_value': xpValue,
     'letter_count': letterCount,
     'cefr_level': cefrLevel,
+    if (vietnameseTranslation != null)
+      'vietnamese_translation': vietnameseTranslation,
   };
 
   ScrambleWord copyWith({
@@ -230,6 +235,7 @@ class ScrambleWord {
     int? xpValue,
     int? letterCount,
     String? cefrLevel,
+    String? vietnameseTranslation,
   }) {
     return ScrambleWord(
       wordId: wordId ?? this.wordId,
@@ -242,6 +248,7 @@ class ScrambleWord {
       xpValue: xpValue ?? this.xpValue,
       letterCount: letterCount ?? this.letterCount,
       cefrLevel: cefrLevel ?? this.cefrLevel,
+      vietnameseTranslation: vietnameseTranslation ?? this.vietnameseTranslation,
     );
   }
 }
@@ -518,6 +525,7 @@ class SpellingBeeWord {
   /// Partial-credit XP.
   final int? xpPartial;
   final int maxReplays;
+  final String? vietnameseTranslation;
 
   const SpellingBeeWord({
     required this.wordId,
@@ -530,6 +538,7 @@ class SpellingBeeWord {
     this.xpFull,
     this.xpPartial,
     this.maxReplays = 3,
+    this.vietnameseTranslation,
   });
 
   factory SpellingBeeWord.fromJson(Map<String, dynamic> json) {
@@ -545,6 +554,7 @@ class SpellingBeeWord {
       xpFull: json['xp_full'] as int?,
       xpPartial: json['xp_partial'] as int?,
       maxReplays: json['max_replays'] as int? ?? 3,
+      vietnameseTranslation: json['vietnamese_translation'] as String?,
     );
   }
 
@@ -559,6 +569,8 @@ class SpellingBeeWord {
     if (xpFull != null) 'xp_full': xpFull,
     if (xpPartial != null) 'xp_partial': xpPartial,
     'max_replays': maxReplays,
+    if (vietnameseTranslation != null)
+      'vietnamese_translation': vietnameseTranslation,
   };
 
   SpellingBeeWord copyWith({
@@ -572,6 +584,7 @@ class SpellingBeeWord {
     int? xpFull,
     int? xpPartial,
     int? maxReplays,
+    String? vietnameseTranslation,
   }) {
     return SpellingBeeWord(
       wordId: wordId ?? this.wordId,
@@ -584,6 +597,7 @@ class SpellingBeeWord {
       xpFull: xpFull ?? this.xpFull,
       xpPartial: xpPartial ?? this.xpPartial,
       maxReplays: maxReplays ?? this.maxReplays,
+      vietnameseTranslation: vietnameseTranslation ?? this.vietnameseTranslation,
     );
   }
 }
@@ -767,6 +781,7 @@ class HangmanGame {
   final int maxLives;
   final int baseXp;
   final List<String> availableCategories;
+  final String? vietnameseTranslation;
 
   const HangmanGame({
     this.sessionId = '',
@@ -779,6 +794,7 @@ class HangmanGame {
     required this.maxLives,
     required this.baseXp,
     this.availableCategories = const [],
+    this.vietnameseTranslation,
   });
 
   factory HangmanGame.fromJson(Map<String, dynamic> json) {
@@ -799,6 +815,7 @@ class HangmanGame {
               ?.map((e) => e as String)
               .toList() ??
           [],
+      vietnameseTranslation: json['vietnamese_translation'] as String?,
     );
   }
 
@@ -813,6 +830,8 @@ class HangmanGame {
     'max_lives': maxLives,
     'base_xp': baseXp,
     'available_categories': availableCategories,
+    if (vietnameseTranslation != null)
+      'vietnamese_translation': vietnameseTranslation,
   };
 
   HangmanGame copyWith({
@@ -826,6 +845,7 @@ class HangmanGame {
     int? maxLives,
     int? baseXp,
     List<String>? availableCategories,
+    String? vietnameseTranslation,
   }) {
     return HangmanGame(
       sessionId: sessionId ?? this.sessionId,
@@ -838,6 +858,7 @@ class HangmanGame {
       maxLives: maxLives ?? this.maxLives,
       baseXp: baseXp ?? this.baseXp,
       availableCategories: availableCategories ?? this.availableCategories,
+      vietnameseTranslation: vietnameseTranslation ?? this.vietnameseTranslation,
     );
   }
 }
diff --git a/flutter-app/lib/features/games/presentation/helpers/game_mistake_recorder.dart b/flutter-app/lib/features/games/presentation/helpers/game_mistake_recorder.dart
new file mode 100644
index 00000000..6e68d42b
--- /dev/null
+++ b/flutter-app/lib/features/games/presentation/helpers/game_mistake_recorder.dart
@@ -0,0 +1,119 @@
+import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+
+class GameMistakeRecorder {
+  final MistakeNotebookRepository _repository;
+  final DateTime Function() _now;
+
+  const GameMistakeRecorder({
+    MistakeNotebookRepository repository = const MistakeNotebookRepository(),
+    DateTime Function()? now,
+  }) : _repository = repository,
+       _now = now ?? DateTime.now;
+
+  Future<void> recordFillBlankMiss({
+    required FillBlankQuestion question,
+    required String sessionId,
+    required int questionIndex,
+    required String selectedAnswer,
+  }) async {
+    if (_isCorrect(selectedAnswer, question.correctAnswer)) return;
+
+    await _repository.saveMistake(
+      _entry(
+        sourceType: 'game_fill_blank',
+        sourceId: _sourceId(sessionId, question.id, questionIndex),
+        questionId: _questionId(question.id, question.sentence, questionIndex),
+        sourceTitle: 'Fill in the Blank',
+        question: question.sentence,
+        selectedAnswer: selectedAnswer,
+        correctAnswer: question.correctAnswer,
+        explanation: question.explanation.isNotEmpty
+            ? question.explanation
+            : question.grammarTip,
+        skill: 'grammar',
+      ),
+    );
+  }
+
+  Future<void> recordGrammarQuizMiss({
+    required GrammarQuizQuestion question,
+    required String sessionId,
+    required int questionIndex,
+    required String selectedAnswer,
+  }) async {
+    if (_isCorrect(selectedAnswer, question.correctAnswer)) return;
+
+    await _repository.saveMistake(
+      _entry(
+        sourceType: 'game_grammar_quiz',
+        sourceId: _sourceId(sessionId, question.id, questionIndex),
+        questionId: _questionId(question.id, question.question, questionIndex),
+        sourceTitle: question.topic.isEmpty
+            ? 'Grammar Quiz'
+            : 'Grammar Quiz - ${_formatTopic(question.topic)}',
+        question: question.question,
+        selectedAnswer: selectedAnswer,
+        correctAnswer: question.correctAnswer,
+        explanation: question.explanation,
+        skill: question.topic.isEmpty ? 'grammar' : question.topic,
+      ),
+    );
+  }
+
+  MistakeNotebookEntry _entry({
+    required String sourceType,
+    required String sourceId,
+    required String questionId,
+    required String sourceTitle,
+    required String question,
+    required String selectedAnswer,
+    required String correctAnswer,
+    required String explanation,
+    required String skill,
+  }) {
+    return MistakeNotebookEntry(
+      id: MistakeNotebookEntry.buildId(
+        sourceType: sourceType,
+        sourceId: sourceId,
+        questionId: questionId,
+        selectedAnswer: selectedAnswer,
+      ),
+      sourceType: sourceType,
+      sourceId: sourceId,
+      sourceTitle: sourceTitle,
+      question: question,
+      selectedAnswer: selectedAnswer,
+      correctAnswer: correctAnswer,
+      explanation: explanation,
+      skill: skill,
+      createdAt: _now(),
+    );
+  }
+
+  bool _isCorrect(String selectedAnswer, String correctAnswer) {
+    return selectedAnswer.trim().toLowerCase() ==
+        correctAnswer.trim().toLowerCase();
+  }
+
+  String _sourceId(String sessionId, String questionId, int questionIndex) {
+    if (sessionId.isNotEmpty) return sessionId;
+    if (questionId.isNotEmpty) return questionId;
+    return 'question_$questionIndex';
+  }
+
+  String _questionId(String id, String question, int questionIndex) {
+    if (id.isNotEmpty) return id;
+    return '$questionIndex:$question';
+  }
+
+  String _formatTopic(String topic) {
+    return topic
+        .replaceAll('_', ' ')
+        .split(' ')
+        .where((word) => word.isNotEmpty)
+        .map((word) => word[0].toUpperCase() + word.substring(1))
+        .join(' ');
+  }
+}
diff --git a/flutter-app/lib/features/games/presentation/screens/fill_blank_screen.dart b/flutter-app/lib/features/games/presentation/screens/fill_blank_screen.dart
index 1394daed..31e51c6b 100644
--- a/flutter-app/lib/features/games/presentation/screens/fill_blank_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/fill_blank_screen.dart
@@ -1,14 +1,27 @@
 import 'dart:async';
+import 'dart:math';
 import 'package:confetti/confetti.dart';
 import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
+import 'package:lexilingo_app/features/games/presentation/helpers/game_mistake_recorder.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
+
+const _fillBlankPowerUps = [
+  ShopItemEntity.effectTimeFreeze,
+  ShopItemEntity.effectExtraTime,
+  ShopItemEntity.effectSkipToken,
+  ShopItemEntity.effectRevealHint,
+  ShopItemEntity.effectLuckyClover,
+  ShopItemEntity.effectScoreMultiplier,
+];
 
 /// Fill in the Blank game screen.
 ///
@@ -33,6 +46,11 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
   bool _isFinishing = false;
   String? _feedbackTip;
   final Map<String, String> _submittedAnswers = {};
+  final Set<int> _eliminatedIndices = {};
+  bool _luckyCloverActive = false;
+  int _scoreMultiplier = 1;
+  final _random = Random();
+  final _mistakeRecorder = const GameMistakeRecorder();
 
   @override
   void initState() {
@@ -65,6 +83,7 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
       _selectedIndex = null;
       _answered = false;
       _feedbackTip = null;
+      _eliminatedIndices.clear();
     });
     _timer?.cancel();
     _timer = Timer.periodic(const Duration(seconds: 1), (t) {
@@ -80,11 +99,64 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
     });
   }
 
+  void _onPowerUpUsed(String itemType, Map<String, dynamic> effects) {
+    if (_answered) return;
+    final game = context.read<GamesProvider>().fillBlank;
+    if (game == null) return;
+    final q = game.questions[_questionIndex];
+    switch (itemType) {
+      case ShopItemEntity.effectTimeFreeze:
+      case ShopItemEntity.effectExtraTime:
+        final seconds = (effects['seconds'] as num?)?.toInt() ?? 10;
+        setState(
+          () => _timeLeft = (_timeLeft + seconds).clamp(
+            0,
+            game.timerSecondsPerQuestion,
+          ),
+        );
+        break;
+      case ShopItemEntity.effectSkipToken:
+        _timer?.cancel();
+        _submittedAnswers[q.id] = '';
+        setState(() => _answered = true);
+        Future.delayed(const Duration(milliseconds: 300), _nextQuestion);
+        break;
+      case ShopItemEntity.effectRevealHint:
+        final wrongIndices = List.generate(q.options.length, (i) => i)
+            .where(
+              (i) =>
+                  q.options[i] != q.correctAnswer &&
+                  !_eliminatedIndices.contains(i),
+            )
+            .toList();
+        wrongIndices.shuffle(_random);
+        setState(() {
+          _eliminatedIndices.addAll(wrongIndices.take(2));
+        });
+        break;
+      case ShopItemEntity.effectLuckyClover:
+        setState(() => _luckyCloverActive = true);
+        break;
+      case ShopItemEntity.effectScoreMultiplier:
+        final multiplier = (effects['multiplier'] as num?)?.toInt() ?? 2;
+        setState(() => _scoreMultiplier = multiplier);
+        break;
+    }
+  }
+
   void _handleTimeout() {
     if (_answered) return;
     final game = context.read<GamesProvider>().fillBlank!;
     final q = game.questions[_questionIndex];
     _submittedAnswers[q.id] = '';
+    unawaited(
+      _mistakeRecorder.recordFillBlankMiss(
+        question: q,
+        sessionId: game.sessionId,
+        questionIndex: _questionIndex,
+        selectedAnswer: '',
+      ),
+    );
     setState(() {
       _answered = true;
       _feedbackTip = q.explanation.isNotEmpty
@@ -95,13 +167,27 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
   }
 
   void _selectAnswer(int index) {
-    if (_answered) return;
+    if (_answered || _eliminatedIndices.contains(index)) return;
     _timer?.cancel();
     final game = context.read<GamesProvider>().fillBlank!;
     final q = game.questions[_questionIndex];
-    final correct = q.options[index] == q.correctAnswer;
+    var correct = q.options[index] == q.correctAnswer;
+    if (!correct && _luckyCloverActive && _random.nextDouble() < 0.3) {
+      correct = true;
+      _luckyCloverActive = false;
+    }
     _submittedAnswers[q.id] = q.options[index];
     if (correct) _correctCount++;
+    if (!correct) {
+      unawaited(
+        _mistakeRecorder.recordFillBlankMiss(
+          question: q,
+          sessionId: game.sessionId,
+          questionIndex: _questionIndex,
+          selectedAnswer: q.options[index],
+        ),
+      );
+    }
     setState(() {
       _selectedIndex = index;
       _answered = true;
@@ -182,15 +268,12 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
     if (!mounted) return;
     final xpResult = await provider.completeGame(
       gameType: GameType.fillBlank,
-      score: _correctCount,
+      score: _correctCount * _scoreMultiplier,
       totalQuestions: game.questions.length,
       correctAnswers: _correctCount,
       answers: [
         for (final question in game.questions)
-          {
-            'id': question.id,
-            'answer': _submittedAnswers[question.id] ?? '',
-          },
+          {'id': question.id, 'answer': _submittedAnswers[question.id] ?? ''},
       ],
     );
     if (!mounted) return;
@@ -201,7 +284,7 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
           result: GameResult(
             gameType: GameType.fillBlank,
             cefrLevel: provider.selectedLevel,
-            score: _correctCount,
+            score: _correctCount * _scoreMultiplier,
             totalQuestions: game.questions.length,
             correctAnswers: _correctCount,
             xpEarned: xpResult?.xpAwarded ?? 0,
@@ -226,263 +309,302 @@ class _FillBlankScreenState extends State<FillBlankScreen> {
           if (provider.isLoading) {
             return const Scaffold(
               body: Center(child: LottieLoadingWidget.medium()),
-          );
-        }
-        final game = provider.fillBlank;
-        if (provider.error != null) {
-          return GameLoadState(
-            message: 'games.loadFailed'.tr(),
-            onRetry: () async {
-              await provider.loadFillBlank();
-              if (mounted) _startQuestion();
-            },
-          );
-        }
-        if (game == null || game.questions.isEmpty) {
-          return GameLoadState(
-            message: 'games.emptyGame'.tr(),
-            onRetry: () async {
-              await provider.loadFillBlank();
-              if (mounted) _startQuestion();
-            },
-          );
-        }
-        if (!_gameLoaded) {
-          return const Scaffold(
-            body: Center(child: LottieLoadingWidget.medium()),
-          );
-        }
-        final q = game.questions[_questionIndex];
+            );
+          }
+          final game = provider.fillBlank;
+          if (provider.error != null) {
+            return GameLoadState(
+              message: 'games.loadFailed'.tr(),
+              onRetry: () async {
+                await provider.loadFillBlank();
+                if (mounted) _startQuestion();
+              },
+            );
+          }
+          if (game == null || game.questions.isEmpty) {
+            return GameLoadState(
+              message: 'games.emptyGame'.tr(),
+              onRetry: () async {
+                await provider.loadFillBlank();
+                if (mounted) _startQuestion();
+              },
+            );
+          }
+          if (!_gameLoaded) {
+            return const Scaffold(
+              body: Center(child: LottieLoadingWidget.medium()),
+            );
+          }
+          final q = game.questions[_questionIndex];
 
-        return Scaffold(
-          appBar: AppBar(
-            backgroundColor: Theme.of(context).colorScheme.surface,
-            elevation: 0,
-            title: Text(
-              'fillBlank.questionProgress'.tr(
-                namedArgs: {
-                  'current': '${_questionIndex + 1}',
-                  'total': '${game.questions.length}',
-                },
+          return Scaffold(
+            appBar: AppBar(
+              backgroundColor: Theme.of(context).colorScheme.surface,
+              elevation: 0,
+              title: Text(
+                'fillBlank.questionProgress'.tr(
+                  namedArgs: {
+                    'current': '${_questionIndex + 1}',
+                    'total': '${game.questions.length}',
+                  },
+                ),
+                style: TextStyle(
+                  color: Theme.of(context).colorScheme.onSurface,
+                ),
               ),
-              style: TextStyle(color: Theme.of(context).colorScheme.onSurface),
             ),
-          ),
-          body: Stack(
-            children: [
-              Column(
-                children: [
-                  // Progress bar
-                  LinearProgressIndicator(
-                    value: (_questionIndex) / game.questions.length,
-                    backgroundColor: Theme.of(
-                      context,
-                    ).colorScheme.surfaceContainerHighest,
-                    color: AppColors.primary,
-                    minHeight: 4,
-                  ),
-                  // Timer bar
-                  Padding(
-                    padding: const EdgeInsets.symmetric(
-                      horizontal: 16,
-                      vertical: 8,
+            body: Stack(
+              children: [
+                Column(
+                  children: [
+                    // Progress bar
+                    LinearProgressIndicator(
+                      value: (_questionIndex) / game.questions.length,
+                      backgroundColor: Theme.of(
+                        context,
+                      ).colorScheme.surfaceContainerHighest,
+                      color: AppColors.primary,
+                      minHeight: 4,
                     ),
-                    child: Row(
-                      children: [
-                        const Icon(
-                          Icons.timer_outlined,
-                          size: 16,
-                          color: AppColors.primary,
+                    Padding(
+                      padding: const EdgeInsets.symmetric(
+                        horizontal: 16,
+                        vertical: 6,
+                      ),
+                      child: GamePowerUpTray(
+                        availableTypes: _fillBlankPowerUps,
+                        enabled: !_answered,
+                        onUse: _onPowerUpUsed,
+                      ),
+                    ),
+                    if (_luckyCloverActive)
+                      const Padding(
+                        padding: EdgeInsets.only(bottom: 6),
+                        child: ActivePowerUpBadge(
+                          itemType: ShopItemEntity.effectLuckyClover,
+                          label: 'Lucky Clover Active',
                         ),
-                        const SizedBox(width: 6),
-                        Expanded(
-                          child: LinearProgressIndicator(
-                            value: _timeLeft / game.timerSecondsPerQuestion,
-                            backgroundColor: Theme.of(
-                              context,
-                            ).colorScheme.surfaceContainerHighest,
-                            color: _timeLeft > 5
-                                ? AppColors.primary
-                                : AppColors.errorBright,
-                            minHeight: 6,
+                      ),
+                    // Timer bar
+                    Padding(
+                      padding: const EdgeInsets.symmetric(
+                        horizontal: 16,
+                        vertical: 8,
+                      ),
+                      child: Row(
+                        children: [
+                          const Icon(
+                            Icons.timer_outlined,
+                            size: 16,
+                            color: AppColors.primary,
                           ),
-                        ),
-                        const SizedBox(width: 6),
-                        Text(
-                          'fillBlank.timerFormat'.tr(
-                            namedArgs: {'seconds': '$_timeLeft'},
+                          const SizedBox(width: 6),
+                          Expanded(
+                            child: LinearProgressIndicator(
+                              value: _timeLeft / game.timerSecondsPerQuestion,
+                              backgroundColor: Theme.of(
+                                context,
+                              ).colorScheme.surfaceContainerHighest,
+                              color: _timeLeft > 5
+                                  ? AppColors.primary
+                                  : AppColors.errorBright,
+                              minHeight: 6,
+                            ),
                           ),
-                          style: TextStyle(
-                            fontWeight: FontWeight.bold,
-                            fontSize: 13,
-                            color: _timeLeft > 5
-                                ? Theme.of(context).colorScheme.onSurfaceVariant
-                                : AppColors.errorBright,
+                          const SizedBox(width: 6),
+                          Text(
+                            'fillBlank.timerFormat'.tr(
+                              namedArgs: {'seconds': '$_timeLeft'},
+                            ),
+                            style: TextStyle(
+                              fontWeight: FontWeight.bold,
+                              fontSize: 13,
+                              color: _timeLeft > 5
+                                  ? Theme.of(
+                                      context,
+                                    ).colorScheme.onSurfaceVariant
+                                  : AppColors.errorBright,
+                            ),
                           ),
-                        ),
-                      ],
+                        ],
+                      ),
                     ),
-                  ),
-                  Expanded(
-                    child: SingleChildScrollView(
-                      padding: const EdgeInsets.all(16),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          // Question sentence
-                          Container(
-                            width: double.infinity,
-                            padding: EdgeInsets.all(20),
-                            decoration: BoxDecoration(
-                              color: Theme.of(context).colorScheme.surface,
-                              borderRadius: BorderRadius.circular(16),
-                              boxShadow: [
-                                BoxShadow(
+                    Expanded(
+                      child: SingleChildScrollView(
+                        padding: const EdgeInsets.all(16),
+                        child: Column(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            // Question sentence
+                            Container(
+                              width: double.infinity,
+                              padding: EdgeInsets.all(20),
+                              decoration: BoxDecoration(
+                                color: Theme.of(context).colorScheme.surface,
+                                borderRadius: BorderRadius.circular(16),
+                                boxShadow: [
+                                  BoxShadow(
+                                    color: Theme.of(context).colorScheme.shadow
+                                        .withValues(alpha: 0.06),
+                                    blurRadius: 8,
+                                  ),
+                                ],
+                              ),
+                              child: Text(
+                                q.sentence,
+                                style: TextStyle(
+                                  fontSize: 18,
+                                  fontWeight: FontWeight.w600,
                                   color: Theme.of(
                                     context,
-                                  ).colorScheme.shadow.withValues(alpha: 0.06),
-                                  blurRadius: 8,
+                                  ).colorScheme.onSurface,
+                                  height: 1.5,
                                 ),
-                              ],
-                            ),
-                            child: Text(
-                              q.sentence,
-                              style: TextStyle(
-                                fontSize: 18,
-                                fontWeight: FontWeight.w600,
-                                color: Theme.of(context).colorScheme.onSurface,
-                                height: 1.5,
                               ),
                             ),
-                          ),
-                          const SizedBox(height: 20),
-                          // Options grid
-                          GridView.count(
-                            physics: const NeverScrollableScrollPhysics(),
-                            shrinkWrap: true,
-                            crossAxisCount: 2,
-                            mainAxisSpacing: 12,
-                            crossAxisSpacing: 12,
-                            childAspectRatio: 2.4,
-                            children: List.generate(q.options.length, (i) {
-                              Color bg = Theme.of(context).colorScheme.surface;
-                              Color border = Theme.of(
-                                context,
-                              ).colorScheme.outlineVariant;
-                              Color text = Theme.of(
-                                context,
-                              ).colorScheme.onSurface;
-                              if (_answered) {
-                                if (q.options[i] == q.correctAnswer) {
-                                  bg = AppColors.greenSuccess.withValues(
-                                    alpha: 0.1,
-                                  );
-                                  border = AppColors.greenSuccess;
-                                  text = AppColors.greenSuccess;
-                                } else if (i == _selectedIndex) {
-                                  bg = Colors.red.withValues(alpha: 0.1);
-                                  border = AppColors.errorBright;
-                                  text = AppColors.errorBright;
+                            const SizedBox(height: 20),
+                            // Options grid
+                            GridView.count(
+                              physics: const NeverScrollableScrollPhysics(),
+                              shrinkWrap: true,
+                              crossAxisCount: 2,
+                              mainAxisSpacing: 12,
+                              crossAxisSpacing: 12,
+                              childAspectRatio: 2.4,
+                              children: List.generate(q.options.length, (i) {
+                                final eliminated = _eliminatedIndices.contains(
+                                  i,
+                                );
+                                Color bg = Theme.of(
+                                  context,
+                                ).colorScheme.surface;
+                                Color border = Theme.of(
+                                  context,
+                                ).colorScheme.outlineVariant;
+                                Color text = Theme.of(
+                                  context,
+                                ).colorScheme.onSurface;
+                                if (_answered) {
+                                  if (q.options[i] == q.correctAnswer) {
+                                    bg = AppColors.greenSuccess.withValues(
+                                      alpha: 0.1,
+                                    );
+                                    border = AppColors.greenSuccess;
+                                    text = AppColors.greenSuccess;
+                                  } else if (i == _selectedIndex) {
+                                    bg = Colors.red.withValues(alpha: 0.1);
+                                    border = AppColors.errorBright;
+                                    text = AppColors.errorBright;
+                                  }
+                                } else if (_selectedIndex == i) {
+                                  bg = AppColors.primary.withValues(alpha: 0.1);
+                                  border = AppColors.primary;
+                                  text = AppColors.primary;
+                                } else if (eliminated) {
+                                  bg = Theme.of(
+                                    context,
+                                  ).colorScheme.surfaceContainerHighest;
+                                  text = Theme.of(context)
+                                      .colorScheme
+                                      .onSurfaceVariant
+                                      .withValues(alpha: 0.4);
                                 }
-                              } else if (_selectedIndex == i) {
-                                bg = AppColors.primary.withValues(alpha: 0.1);
-                                border = AppColors.primary;
-                                text = AppColors.primary;
-                              }
-                              return GestureDetector(
-                                onTap: () => _selectAnswer(i),
-                                child: AnimatedContainer(
-                                  duration: const Duration(milliseconds: 200),
-                                  padding: const EdgeInsets.symmetric(
-                                    horizontal: 12,
-                                  ),
-                                  decoration: BoxDecoration(
-                                    color: bg,
-                                    borderRadius: BorderRadius.circular(12),
-                                    border: Border.all(
-                                      color: border,
-                                      width: 1.5,
+                                return GestureDetector(
+                                  onTap: eliminated
+                                      ? null
+                                      : () => _selectAnswer(i),
+                                  child: AnimatedContainer(
+                                    duration: const Duration(milliseconds: 200),
+                                    padding: const EdgeInsets.symmetric(
+                                      horizontal: 12,
                                     ),
-                                  ),
-                                  alignment: Alignment.center,
-                                  child: Text(
-                                    q.options[i],
-                                    style: TextStyle(
-                                      fontWeight: FontWeight.w600,
-                                      fontSize: 14,
-                                      color: text,
+                                    decoration: BoxDecoration(
+                                      color: bg,
+                                      borderRadius: BorderRadius.circular(12),
+                                      border: Border.all(
+                                        color: border,
+                                        width: 1.5,
+                                      ),
+                                    ),
+                                    alignment: Alignment.center,
+                                    child: Text(
+                                      q.options[i],
+                                      style: TextStyle(
+                                        fontWeight: FontWeight.w600,
+                                        fontSize: 14,
+                                        color: text,
+                                      ),
+                                      textAlign: TextAlign.center,
                                     ),
-                                    textAlign: TextAlign.center,
                                   ),
-                                ),
-                              );
-                            }),
-                          ),
-                          // Feedback tip
-                          if (_feedbackTip != null) ...[
-                            const SizedBox(height: 16),
-                            AnimatedContainer(
-                              duration: const Duration(milliseconds: 300),
-                              width: double.infinity,
-                              padding: const EdgeInsets.all(14),
-                              decoration: BoxDecoration(
-                                color:
-                                    _answered &&
-                                        _selectedIndex != null &&
-                                        q.options[_selectedIndex!] ==
-                                            q.correctAnswer
-                                    ? AppColors.greenSuccess.withValues(
-                                        alpha: 0.1,
-                                      )
-                                    : Colors.red.withValues(alpha: 0.1),
-                                borderRadius: BorderRadius.circular(12),
-                                border: Border.all(
+                                );
+                              }),
+                            ),
+                            // Feedback tip
+                            if (_feedbackTip != null) ...[
+                              const SizedBox(height: 16),
+                              AnimatedContainer(
+                                duration: const Duration(milliseconds: 300),
+                                width: double.infinity,
+                                padding: const EdgeInsets.all(14),
+                                decoration: BoxDecoration(
                                   color:
                                       _answered &&
                                           _selectedIndex != null &&
                                           q.options[_selectedIndex!] ==
                                               q.correctAnswer
-                                      ? AppColors.greenSuccess
-                                      : AppColors.errorBright,
+                                      ? AppColors.greenSuccess.withValues(
+                                          alpha: 0.1,
+                                        )
+                                      : Colors.red.withValues(alpha: 0.1),
+                                  borderRadius: BorderRadius.circular(12),
+                                  border: Border.all(
+                                    color:
+                                        _answered &&
+                                            _selectedIndex != null &&
+                                            q.options[_selectedIndex!] ==
+                                                q.correctAnswer
+                                        ? AppColors.greenSuccess
+                                        : AppColors.errorBright,
+                                  ),
                                 ),
-                              ),
-                              child: Text(
-                                _feedbackTip!,
-                                style: TextStyle(
-                                  fontSize: 13,
-                                  color: Theme.of(
-                                    context,
-                                  ).colorScheme.onSurface,
-                                  height: 1.4,
+                                child: Text(
+                                  _feedbackTip!,
+                                  style: TextStyle(
+                                    fontSize: 13,
+                                    color: Theme.of(
+                                      context,
+                                    ).colorScheme.onSurface,
+                                    height: 1.4,
+                                  ),
                                 ),
                               ),
-                            ),
+                            ],
                           ],
-                        ],
+                        ),
                       ),
                     ),
-                  ),
-                ],
-              ),
-              // Confetti overlay — fires on win (skill: gamification-confetti-win)
-              Align(
-                alignment: Alignment.topCenter,
-                child: ConfettiWidget(
-                  confettiController: _confettiController,
-                  blastDirectionality: BlastDirectionality.explosive,
-                  numberOfParticles: 20,
-                  gravity: 0.4,
-                  colors: const [
-                    AppColors.primary,
-                    Colors.yellow,
-                    AppColors.greenSuccessBright,
-                    AppColors.orange,
                   ],
                 ),
-              ),
-            ],
-          ),
-        );
+                // Confetti overlay — fires on win (skill: gamification-confetti-win)
+                Align(
+                  alignment: Alignment.topCenter,
+                  child: ConfettiWidget(
+                    confettiController: _confettiController,
+                    blastDirectionality: BlastDirectionality.explosive,
+                    numberOfParticles: 20,
+                    gravity: 0.4,
+                    colors: const [
+                      AppColors.primary,
+                      Colors.yellow,
+                      AppColors.greenSuccessBright,
+                      AppColors.orange,
+                    ],
+                  ),
+                ),
+              ],
+            ),
+          );
         },
       ),
     );
diff --git a/flutter-app/lib/features/games/presentation/screens/games_hub_screen.dart b/flutter-app/lib/features/games/presentation/screens/games_hub_screen.dart
index d5418ac0..b5db1a6e 100644
--- a/flutter-app/lib/features/games/presentation/screens/games_hub_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/games_hub_screen.dart
@@ -9,6 +9,10 @@ import 'package:lexilingo_app/features/games/presentation/widgets/xp_progress_ba
 import 'package:lexilingo_app/features/games/presentation/widgets/streak_indicator.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_card.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/daily_challenge_card.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/daily_challenge_mapper.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/daily_challenge_entity.dart'
+    as progress;
+import 'package:lexilingo_app/features/progress/presentation/providers/daily_challenges_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/word_scramble_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/fill_blank_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/matching_game_screen.dart';
@@ -60,6 +64,7 @@ class _GamesHubScreenState extends State<GamesHubScreen>
       final p = context.read<GamesProvider>();
       p.loadXPProfile();
       p.loadLeaderboard();
+      context.read<DailyChallengesProvider>().loadChallenges();
       Future.delayed(const Duration(milliseconds: 600), () {
         if (mounted) _podiumController.forward();
       });
@@ -97,43 +102,49 @@ class _GamesHubScreenState extends State<GamesHubScreen>
     final titleColor = isDark ? AppColors.textInverted : AppColors.textDark;
     return Scaffold(
       backgroundColor: Theme.of(context).colorScheme.surfaceContainer,
-      body: Consumer<GamesProvider>(
-        builder: (context, provider, _) {
-          return CustomScrollView(
-            slivers: [
-              _buildAppBar(provider, titleColor),
-              SliverToBoxAdapter(
-                child: Padding(
-                  padding: const EdgeInsets.symmetric(horizontal: 16),
-                  child: Column(
-                    crossAxisAlignment: CrossAxisAlignment.start,
-                    children: [
-                      const SizedBox(height: 16),
-                      _buildXpHeader(provider),
-                      const SizedBox(height: 16),
-                      _buildDailyChallenge(context),
-                      const SizedBox(height: 20),
-                      _buildLevelPicker(provider),
-                      const SizedBox(height: 20),
-                      _buildSectionTitle(
-                        'gamesHub.gamesSectionTitle'.tr(),
-                        titleColor,
+      body: Consumer2<GamesProvider, DailyChallengesProvider>(
+        builder: (context, provider, challengesProvider, _) {
+          return Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 1180),
+              child: CustomScrollView(
+                slivers: [
+                  _buildAppBar(provider, titleColor),
+                  SliverToBoxAdapter(
+                    child: Padding(
+                      padding: const EdgeInsets.symmetric(horizontal: 16),
+                      child: Column(
+                        crossAxisAlignment: CrossAxisAlignment.start,
+                        children: [
+                          const SizedBox(height: 16),
+                          _buildXpHeader(provider),
+                          const SizedBox(height: 16),
+                          _buildDailyChallenge(context, challengesProvider),
+                          const SizedBox(height: 20),
+                          _buildLevelPicker(provider),
+                          const SizedBox(height: 20),
+                          _buildSectionTitle(
+                            'gamesHub.gamesSectionTitle'.tr(),
+                            titleColor,
+                          ),
+                          const SizedBox(height: 12),
+                          _buildGameGrid(context, provider),
+                          const SizedBox(height: 24),
+                          _buildSectionTitle(
+                            'gamesHub.leaderboardSectionTitle'.tr(),
+                            titleColor,
+                          ),
+                          const SizedBox(height: 12),
+                          _buildLeaderboard(provider),
+                          const SizedBox(height: 32),
+                        ],
                       ),
-                      const SizedBox(height: 12),
-                      _buildGameGrid(context, provider),
-                      const SizedBox(height: 24),
-                      _buildSectionTitle(
-                        'gamesHub.leaderboardSectionTitle'.tr(),
-                        titleColor,
-                      ),
-                      const SizedBox(height: 12),
-                      _buildLeaderboard(provider),
-                      const SizedBox(height: 32),
-                    ],
+                    ),
                   ),
-                ),
+                ],
               ),
-            ],
+            ),
           );
         },
       ),
@@ -259,31 +270,84 @@ class _GamesHubScreenState extends State<GamesHubScreen>
     );
   }
 
-  /// Hardcoded demo daily challenge card.
-  ///
-  /// In production this would be loaded from the backend.
-  Widget _buildDailyChallenge(BuildContext context) {
+  progress.DailyChallengeEntity? _selectDailyChallenge(
+    DailyChallengesProvider provider,
+  ) {
+    if (provider.challenges.isEmpty) return null;
+    return provider.challenges.firstWhere(
+      (challenge) => !challenge.isCompleted,
+      orElse: () => provider.challenges.first,
+    );
+  }
+
+  Future<void> _handleDailyChallengeTap(
+    progress.DailyChallengeEntity challenge,
+    DailyChallengesProvider provider,
+  ) async {
+    if (challenge.isCompleted) {
+      final claimed = await provider.claimReward(challenge.id);
+      if (!mounted) return;
+      if (claimed) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text('dailyChallenges.rewardClaimed'.tr())),
+        );
+        await provider.refresh();
+      }
+      return;
+    }
+
+    _navigateToGame(context, gameTypeForDailyChallenge(challenge));
+  }
+
+  Widget _buildDailyChallenge(
+    BuildContext context,
+    DailyChallengesProvider challengesProvider,
+  ) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
     final titleColor = isDark ? AppColors.textInverted : AppColors.textDark;
-    final demo = DailyChallenge(
-      gameType: GameType.fillBlank.apiKey,
-      description: 'Complete 5 Fill in the Blank questions',
-      bonusMultiplier: 2,
-      completed: false,
-      resetsAt: DateTime.now().add(const Duration(days: 1)),
-    );
+    final selectedChallenge = _selectDailyChallenge(challengesProvider);
+    final challenge = selectedChallenge != null
+        ? toGameDailyChallenge(selectedChallenge)
+        : DailyChallenge(
+            gameType: GameType.fillBlank.apiKey,
+            description: 'Complete 5 Fill in the Blank questions',
+            bonusMultiplier: 2,
+            completed: false,
+            resetsAt: DateTime.now().add(const Duration(days: 1)),
+          );
+    final rewardClaimable =
+        selectedChallenge?.isCompleted == true &&
+        !challengesProvider.isRewardClaimed(selectedChallenge!.id);
+
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
         _buildSectionTitle('gamesHub.dailyChallengeLabel'.tr(), titleColor),
         const SizedBox(height: 10),
-        DailyChallengeCard(
-          challenge: demo,
-          onTap: () => Navigator.push(
-            context,
-            MaterialPageRoute(builder: (_) => const FillBlankScreen()),
+        if (challengesProvider.isLoading && selectedChallenge == null)
+          Shimmer.fromColors(
+            baseColor: AppColors.grey200,
+            highlightColor: AppColors.grey100,
+            child: Container(
+              height: 88,
+              decoration: BoxDecoration(
+                color: Theme.of(context).colorScheme.surface,
+                borderRadius: BorderRadius.circular(16),
+              ),
+            ),
+          )
+        else
+          DailyChallengeCard(
+            challenge: challenge,
+            allowCompletedTap: rewardClaimable,
+            onTap: () {
+              if (selectedChallenge != null) {
+                _handleDailyChallengeTap(selectedChallenge, challengesProvider);
+                return;
+              }
+              _navigateToGame(context, GameType.fillBlank);
+            },
           ),
-        ),
       ],
     );
   }
@@ -350,21 +414,32 @@ class _GamesHubScreenState extends State<GamesHubScreen>
   }
 
   Widget _buildGameGrid(BuildContext context, GamesProvider provider) {
-    return GridView.builder(
-      physics: const NeverScrollableScrollPhysics(),
-      shrinkWrap: true,
-      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
-        crossAxisCount: 2,
-        mainAxisSpacing: 12,
-        crossAxisSpacing: 12,
-        childAspectRatio: 0.85,
-      ),
-      itemCount: GameType.values.length,
-      itemBuilder: (context, index) {
-        final type = GameType.values[index];
-        return GameCard(
-          gameType: type,
-          onTap: () => _navigateToGame(context, type),
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        final width = constraints.maxWidth;
+        final crossAxisCount = width >= 1000
+            ? 4
+            : width >= 680
+            ? 3
+            : 2;
+
+        return GridView.builder(
+          physics: const NeverScrollableScrollPhysics(),
+          shrinkWrap: true,
+          gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
+            crossAxisCount: crossAxisCount,
+            mainAxisSpacing: 12,
+            crossAxisSpacing: 12,
+            childAspectRatio: 0.85,
+          ),
+          itemCount: GameType.values.length,
+          itemBuilder: (context, index) {
+            final type = GameType.values[index];
+            return GameCard(
+              gameType: type,
+              onTap: () => _navigateToGame(context, type),
+            );
+          },
         );
       },
     );
diff --git a/flutter-app/lib/features/games/presentation/screens/grammar_quiz_screen.dart b/flutter-app/lib/features/games/presentation/screens/grammar_quiz_screen.dart
index 0bbb8ec1..71b19f02 100644
--- a/flutter-app/lib/features/games/presentation/screens/grammar_quiz_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/grammar_quiz_screen.dart
@@ -1,14 +1,27 @@
 import 'dart:async';
+import 'dart:math';
 import 'package:confetti/confetti.dart';
 import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
+import 'package:lexilingo_app/features/games/presentation/helpers/game_mistake_recorder.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
+
+const _grammarQuizPowerUps = [
+  ShopItemEntity.effectTimeFreeze,
+  ShopItemEntity.effectExtraTime,
+  ShopItemEntity.effectSkipToken,
+  ShopItemEntity.effectRevealHint,
+  ShopItemEntity.effectLuckyClover,
+  ShopItemEntity.effectScoreMultiplier,
+];
 
 /// Grammar Quiz game screen.
 ///
@@ -33,6 +46,11 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
   bool _isFinishing = false;
   String? _feedbackText;
   final Map<String, String> _submittedAnswers = {};
+  final Set<int> _eliminatedIndices = {};
+  bool _luckyCloverActive = false;
+  int _scoreMultiplier = 1;
+  final _random = Random();
+  final _mistakeRecorder = const GameMistakeRecorder();
 
   // Per-topic correct tracking for mastery message
   final Map<String, int> _topicCorrect = {};
@@ -67,6 +85,7 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
       _selectedIndex = null;
       _answered = false;
       _feedbackText = null;
+      _eliminatedIndices.clear();
     });
     _timer?.cancel();
     _timer = Timer.periodic(const Duration(seconds: 1), (t) {
@@ -82,12 +101,65 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
     });
   }
 
+  void _onPowerUpUsed(String itemType, Map<String, dynamic> effects) {
+    if (_answered) return;
+    final game = context.read<GamesProvider>().grammarQuiz;
+    if (game == null) return;
+    final q = game.questions[_questionIndex];
+    switch (itemType) {
+      case ShopItemEntity.effectTimeFreeze:
+      case ShopItemEntity.effectExtraTime:
+        final seconds = (effects['seconds'] as num?)?.toInt() ?? 10;
+        setState(
+          () => _timeLeft = (_timeLeft + seconds).clamp(
+            0,
+            game.timerSecondsPerQuestion,
+          ),
+        );
+        break;
+      case ShopItemEntity.effectSkipToken:
+        _timer?.cancel();
+        _submittedAnswers[q.id] = '';
+        setState(() => _answered = true);
+        Future.delayed(const Duration(milliseconds: 300), _nextQuestion);
+        break;
+      case ShopItemEntity.effectRevealHint:
+        final wrongIndices = List.generate(q.options.length, (i) => i)
+            .where(
+              (i) =>
+                  q.options[i] != q.correctAnswer &&
+                  !_eliminatedIndices.contains(i),
+            )
+            .toList();
+        wrongIndices.shuffle(_random);
+        setState(() {
+          _eliminatedIndices.addAll(wrongIndices.take(2));
+        });
+        break;
+      case ShopItemEntity.effectLuckyClover:
+        setState(() => _luckyCloverActive = true);
+        break;
+      case ShopItemEntity.effectScoreMultiplier:
+        final multiplier = (effects['multiplier'] as num?)?.toInt() ?? 2;
+        setState(() => _scoreMultiplier = multiplier);
+        break;
+    }
+  }
+
   void _handleTimeout() {
     if (_answered) return;
     final game = context.read<GamesProvider>().grammarQuiz!;
     final q = game.questions[_questionIndex];
     _submittedAnswers[q.id] = '';
     _recordTopic(q.topic, false);
+    unawaited(
+      _mistakeRecorder.recordGrammarQuizMiss(
+        question: q,
+        sessionId: game.sessionId,
+        questionIndex: _questionIndex,
+        selectedAnswer: '',
+      ),
+    );
     setState(() {
       _answered = true;
       _feedbackText =
@@ -97,14 +169,28 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
   }
 
   void _selectAnswer(int index) {
-    if (_answered) return;
+    if (_answered || _eliminatedIndices.contains(index)) return;
     _timer?.cancel();
     final game = context.read<GamesProvider>().grammarQuiz!;
     final q = game.questions[_questionIndex];
-    final correct = q.options[index] == q.correctAnswer;
+    var correct = q.options[index] == q.correctAnswer;
+    if (!correct && _luckyCloverActive && _random.nextDouble() < 0.3) {
+      correct = true;
+      _luckyCloverActive = false;
+    }
     _submittedAnswers[q.id] = q.options[index];
     if (correct) _correctCount++;
     _recordTopic(q.topic, correct);
+    if (!correct) {
+      unawaited(
+        _mistakeRecorder.recordGrammarQuizMiss(
+          question: q,
+          sessionId: game.sessionId,
+          questionIndex: _questionIndex,
+          selectedAnswer: q.options[index],
+        ),
+      );
+    }
     final masteryMsg = _buildMasteryMessage(q.topic);
     setState(() {
       _selectedIndex = index;
@@ -218,15 +304,12 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
     if (!mounted) return;
     final xpResult = await provider.completeGame(
       gameType: GameType.grammarQuiz,
-      score: _correctCount,
+      score: _correctCount * _scoreMultiplier,
       totalQuestions: game.questions.length,
       correctAnswers: _correctCount,
       answers: [
         for (final question in game.questions)
-          {
-            'id': question.id,
-            'answer': _submittedAnswers[question.id] ?? '',
-          },
+          {'id': question.id, 'answer': _submittedAnswers[question.id] ?? ''},
       ],
     );
     if (!mounted) return;
@@ -237,7 +320,7 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
           result: GameResult(
             gameType: GameType.grammarQuiz,
             cefrLevel: provider.selectedLevel,
-            score: _correctCount,
+            score: _correctCount * _scoreMultiplier,
             totalQuestions: game.questions.length,
             correctAnswers: _correctCount,
             xpEarned: xpResult?.xpAwarded ?? 0,
@@ -270,253 +353,284 @@ class _GrammarQuizScreenState extends State<GrammarQuizScreen> {
               message: 'games.loadFailed'.tr(),
               onRetry: () async {
                 await provider.loadGrammarQuiz();
-              if (mounted) _startQuestion();
-            },
-          );
-        }
-        if (game == null || game.questions.isEmpty) {
-          return GameLoadState(
-            message: 'games.emptyGame'.tr(),
-            onRetry: () async {
-              await provider.loadGrammarQuiz();
-              if (mounted) _startQuestion();
-            },
-          );
-        }
-        if (!_gameLoaded) {
-          return const Scaffold(
-            body: Center(child: LottieLoadingWidget.medium()),
-          );
-        }
-        final q = game.questions[_questionIndex];
+                if (mounted) _startQuestion();
+              },
+            );
+          }
+          if (game == null || game.questions.isEmpty) {
+            return GameLoadState(
+              message: 'games.emptyGame'.tr(),
+              onRetry: () async {
+                await provider.loadGrammarQuiz();
+                if (mounted) _startQuestion();
+              },
+            );
+          }
+          if (!_gameLoaded) {
+            return const Scaffold(
+              body: Center(child: LottieLoadingWidget.medium()),
+            );
+          }
+          final q = game.questions[_questionIndex];
 
-        return Scaffold(
-          appBar: AppBar(
-            backgroundColor: Theme.of(context).colorScheme.surface,
-            elevation: 0,
-            title: Text(
-              'grammarQuiz.questionProgress'.tr(
-                namedArgs: {
-                  'current': '${_questionIndex + 1}',
-                  'total': '${game.questions.length}',
-                },
-              ),
-              style: TextStyle(color: Theme.of(context).colorScheme.onSurface),
-            ),
-            actions: [
-              Padding(
-                padding: const EdgeInsets.only(right: 12),
-                child: Center(
-                  child: _TimerWidget(
-                    timeLeft: _timeLeft,
-                    total: game.timerSecondsPerQuestion,
-                  ),
+          return Scaffold(
+            appBar: AppBar(
+              backgroundColor: Theme.of(context).colorScheme.surface,
+              elevation: 0,
+              title: Text(
+                'grammarQuiz.questionProgress'.tr(
+                  namedArgs: {
+                    'current': '${_questionIndex + 1}',
+                    'total': '${game.questions.length}',
+                  },
+                ),
+                style: TextStyle(
+                  color: Theme.of(context).colorScheme.onSurface,
                 ),
               ),
-            ],
-          ),
-          body: Stack(
-            children: [
-              Column(
-                children: [
-                  LinearProgressIndicator(
-                    value: _questionIndex / game.questions.length,
-                    backgroundColor: Theme.of(
-                      context,
-                    ).colorScheme.surfaceContainerHighest,
-                    color: AppColors.primary,
-                    minHeight: 4,
+              actions: [
+                Padding(
+                  padding: const EdgeInsets.only(right: 12),
+                  child: Center(
+                    child: _TimerWidget(
+                      timeLeft: _timeLeft,
+                      total: game.timerSecondsPerQuestion,
+                    ),
                   ),
-                  Expanded(
-                    child: SingleChildScrollView(
-                      padding: const EdgeInsets.all(16),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          // Topic chip
-                          Chip(
-                            label: Text(
-                              _formatTopic(game.topic),
-                              style: const TextStyle(
-                                color: AppColors.primary,
-                                fontSize: 12,
-                                fontWeight: FontWeight.bold,
+                ),
+              ],
+            ),
+            body: Stack(
+              children: [
+                Column(
+                  children: [
+                    LinearProgressIndicator(
+                      value: _questionIndex / game.questions.length,
+                      backgroundColor: Theme.of(
+                        context,
+                      ).colorScheme.surfaceContainerHighest,
+                      color: AppColors.primary,
+                      minHeight: 4,
+                    ),
+                    Expanded(
+                      child: SingleChildScrollView(
+                        padding: const EdgeInsets.all(16),
+                        child: Column(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            GamePowerUpTray(
+                              availableTypes: _grammarQuizPowerUps,
+                              enabled: !_answered,
+                              onUse: _onPowerUpUsed,
+                            ),
+                            if (_luckyCloverActive)
+                              const Padding(
+                                padding: EdgeInsets.only(top: 6),
+                                child: ActivePowerUpBadge(
+                                  itemType: ShopItemEntity.effectLuckyClover,
+                                  label: 'Lucky Clover Active',
+                                ),
+                              ),
+                            const SizedBox(height: 12),
+                            // Topic chip
+                            Chip(
+                              label: Text(
+                                _formatTopic(game.topic),
+                                style: const TextStyle(
+                                  color: AppColors.primary,
+                                  fontSize: 12,
+                                  fontWeight: FontWeight.bold,
+                                ),
                               ),
+                              backgroundColor: AppColors.primary.withValues(
+                                alpha: 0.1,
+                              ),
+                              side: const BorderSide(color: AppColors.primary),
                             ),
-                            backgroundColor: AppColors.primary.withValues(
-                              alpha: 0.1,
+                            const SizedBox(height: 12),
+                            // Timer bar
+                            LinearProgressIndicator(
+                              value: _timeLeft / game.timerSecondsPerQuestion,
+                              backgroundColor: Theme.of(
+                                context,
+                              ).colorScheme.surfaceContainerHighest,
+                              color: _timeLeft > 4
+                                  ? AppColors.primary
+                                  : AppColors.errorBright,
+                              minHeight: 6,
                             ),
-                            side: const BorderSide(color: AppColors.primary),
-                          ),
-                          const SizedBox(height: 12),
-                          // Timer bar
-                          LinearProgressIndicator(
-                            value: _timeLeft / game.timerSecondsPerQuestion,
-                            backgroundColor: Theme.of(
-                              context,
-                            ).colorScheme.surfaceContainerHighest,
-                            color: _timeLeft > 4
-                                ? AppColors.primary
-                                : AppColors.errorBright,
-                            minHeight: 6,
-                          ),
-                          const SizedBox(height: 16),
-                          // Question
-                          Container(
-                            width: double.infinity,
-                            padding: EdgeInsets.all(18),
-                            decoration: BoxDecoration(
-                              color: Theme.of(context).colorScheme.surface,
-                              borderRadius: BorderRadius.circular(14),
-                              boxShadow: [
-                                BoxShadow(
+                            const SizedBox(height: 16),
+                            // Question
+                            Container(
+                              width: double.infinity,
+                              padding: EdgeInsets.all(18),
+                              decoration: BoxDecoration(
+                                color: Theme.of(context).colorScheme.surface,
+                                borderRadius: BorderRadius.circular(14),
+                                boxShadow: [
+                                  BoxShadow(
+                                    color: Theme.of(context).colorScheme.shadow
+                                        .withValues(alpha: 0.05),
+                                    blurRadius: 6,
+                                  ),
+                                ],
+                              ),
+                              child: Text(
+                                q.question,
+                                style: TextStyle(
+                                  fontSize: 17,
+                                  fontWeight: FontWeight.w600,
                                   color: Theme.of(
                                     context,
-                                  ).colorScheme.shadow.withValues(alpha: 0.05),
-                                  blurRadius: 6,
+                                  ).colorScheme.onSurface,
+                                  height: 1.5,
                                 ),
-                              ],
-                            ),
-                            child: Text(
-                              q.question,
-                              style: TextStyle(
-                                fontSize: 17,
-                                fontWeight: FontWeight.w600,
-                                color: Theme.of(context).colorScheme.onSurface,
-                                height: 1.5,
                               ),
                             ),
-                          ),
-                          const SizedBox(height: 16),
-                          // Answer cards
-                          ...List.generate(q.options.length, (i) {
-                            Color bg = Theme.of(context).colorScheme.surface;
-                            Color border = Theme.of(
-                              context,
-                            ).colorScheme.outlineVariant;
-                            Color text = Theme.of(
-                              context,
-                            ).colorScheme.onSurface;
-                            IconData? icon;
-                            if (_answered) {
-                              if (q.options[i] == q.correctAnswer) {
-                                bg = AppColors.greenSuccess.withValues(
-                                  alpha: 0.1,
-                                );
-                                border = AppColors.greenSuccess;
-                                text = AppColors.greenSuccess;
-                                icon = Icons.check_circle_outline;
-                              } else if (i == _selectedIndex) {
-                                bg = Colors.red.withValues(alpha: 0.08);
-                                border = AppColors.errorBright;
-                                text = AppColors.errorBright;
-                                icon = Icons.cancel_outlined;
+                            const SizedBox(height: 16),
+                            // Answer cards
+                            ...List.generate(q.options.length, (i) {
+                              final eliminated = _eliminatedIndices.contains(i);
+                              Color bg = Theme.of(context).colorScheme.surface;
+                              Color border = Theme.of(
+                                context,
+                              ).colorScheme.outlineVariant;
+                              Color text = Theme.of(
+                                context,
+                              ).colorScheme.onSurface;
+                              IconData? icon;
+                              if (_answered) {
+                                if (q.options[i] == q.correctAnswer) {
+                                  bg = AppColors.greenSuccess.withValues(
+                                    alpha: 0.1,
+                                  );
+                                  border = AppColors.greenSuccess;
+                                  text = AppColors.greenSuccess;
+                                  icon = Icons.check_circle_outline;
+                                } else if (i == _selectedIndex) {
+                                  bg = Colors.red.withValues(alpha: 0.08);
+                                  border = AppColors.errorBright;
+                                  text = AppColors.errorBright;
+                                  icon = Icons.cancel_outlined;
+                                }
+                              } else if (_selectedIndex == i) {
+                                bg = AppColors.primary.withValues(alpha: 0.1);
+                                border = AppColors.primary;
+                                text = AppColors.primary;
+                              } else if (eliminated) {
+                                bg = Theme.of(
+                                  context,
+                                ).colorScheme.surfaceContainerHighest;
+                                text = Theme.of(context)
+                                    .colorScheme
+                                    .onSurfaceVariant
+                                    .withValues(alpha: 0.4);
                               }
-                            } else if (_selectedIndex == i) {
-                              bg = AppColors.primary.withValues(alpha: 0.1);
-                              border = AppColors.primary;
-                              text = AppColors.primary;
-                            }
-                            return GestureDetector(
-                              onTap: () => _selectAnswer(i),
-                              child: AnimatedContainer(
-                                duration: const Duration(milliseconds: 180),
-                                margin: const EdgeInsets.only(bottom: 10),
-                                padding: const EdgeInsets.symmetric(
-                                  horizontal: 16,
-                                  vertical: 14,
-                                ),
-                                decoration: BoxDecoration(
-                                  color: bg,
-                                  borderRadius: BorderRadius.circular(12),
-                                  border: Border.all(color: border, width: 1.5),
-                                ),
-                                child: Row(
-                                  children: [
-                                    if (icon != null) ...[
-                                      Icon(icon, color: border, size: 18),
-                                      const SizedBox(width: 8),
-                                    ],
-                                    Expanded(
-                                      child: Text(
-                                        q.options[i],
-                                        style: TextStyle(
-                                          fontSize: 14,
-                                          fontWeight: FontWeight.w500,
-                                          color: text,
+                              return GestureDetector(
+                                onTap: eliminated
+                                    ? null
+                                    : () => _selectAnswer(i),
+                                child: AnimatedContainer(
+                                  duration: const Duration(milliseconds: 180),
+                                  margin: const EdgeInsets.only(bottom: 10),
+                                  padding: const EdgeInsets.symmetric(
+                                    horizontal: 16,
+                                    vertical: 14,
+                                  ),
+                                  decoration: BoxDecoration(
+                                    color: bg,
+                                    borderRadius: BorderRadius.circular(12),
+                                    border: Border.all(
+                                      color: border,
+                                      width: 1.5,
+                                    ),
+                                  ),
+                                  child: Row(
+                                    children: [
+                                      if (icon != null) ...[
+                                        Icon(icon, color: border, size: 18),
+                                        const SizedBox(width: 8),
+                                      ],
+                                      Expanded(
+                                        child: Text(
+                                          q.options[i],
+                                          style: TextStyle(
+                                            fontSize: 14,
+                                            fontWeight: FontWeight.w500,
+                                            color: text,
+                                          ),
                                         ),
                                       ),
-                                    ),
-                                  ],
+                                    ],
+                                  ),
                                 ),
-                              ),
-                            );
-                          }),
-                          // Feedback
-                          if (_feedbackText != null) ...[
-                            const SizedBox(height: 8),
-                            AnimatedContainer(
-                              duration: const Duration(milliseconds: 250),
-                              width: double.infinity,
-                              padding: const EdgeInsets.all(14),
-                              decoration: BoxDecoration(
-                                color:
-                                    _answered &&
-                                        _selectedIndex != null &&
-                                        q.options[_selectedIndex!] ==
-                                            q.correctAnswer
-                                    ? AppColors.greenSuccess.withValues(
-                                        alpha: 0.08,
-                                      )
-                                    : Colors.red.withValues(alpha: 0.07),
-                                borderRadius: BorderRadius.circular(12),
-                                border: Border.all(
+                              );
+                            }),
+                            // Feedback
+                            if (_feedbackText != null) ...[
+                              const SizedBox(height: 8),
+                              AnimatedContainer(
+                                duration: const Duration(milliseconds: 250),
+                                width: double.infinity,
+                                padding: const EdgeInsets.all(14),
+                                decoration: BoxDecoration(
                                   color:
                                       _answered &&
                                           _selectedIndex != null &&
                                           q.options[_selectedIndex!] ==
                                               q.correctAnswer
-                                      ? AppColors.greenSuccess
-                                      : AppColors.errorBright,
+                                      ? AppColors.greenSuccess.withValues(
+                                          alpha: 0.08,
+                                        )
+                                      : Colors.red.withValues(alpha: 0.07),
+                                  borderRadius: BorderRadius.circular(12),
+                                  border: Border.all(
+                                    color:
+                                        _answered &&
+                                            _selectedIndex != null &&
+                                            q.options[_selectedIndex!] ==
+                                                q.correctAnswer
+                                        ? AppColors.greenSuccess
+                                        : AppColors.errorBright,
+                                  ),
                                 ),
-                              ),
-                              child: Text(
-                                _feedbackText!,
-                                style: TextStyle(
-                                  fontSize: 13,
-                                  color: Theme.of(
-                                    context,
-                                  ).colorScheme.onSurface,
-                                  height: 1.4,
+                                child: Text(
+                                  _feedbackText!,
+                                  style: TextStyle(
+                                    fontSize: 13,
+                                    color: Theme.of(
+                                      context,
+                                    ).colorScheme.onSurface,
+                                    height: 1.4,
+                                  ),
                                 ),
                               ),
-                            ),
+                            ],
                           ],
-                        ],
+                        ),
                       ),
                     ),
-                  ),
-                ],
-              ),
-              // Confetti overlay (skill: gamification-confetti-win)
-              Align(
-                alignment: Alignment.topCenter,
-                child: ConfettiWidget(
-                  confettiController: _confettiController,
-                  blastDirectionality: BlastDirectionality.explosive,
-                  numberOfParticles: 20,
-                  gravity: 0.4,
-                  colors: const [
-                    AppColors.primary,
-                    Colors.yellow,
-                    AppColors.greenSuccessBright,
-                    AppColors.orange,
                   ],
                 ),
-              ),
-            ],
-          ),
-        );
+                // Confetti overlay (skill: gamification-confetti-win)
+                Align(
+                  alignment: Alignment.topCenter,
+                  child: ConfettiWidget(
+                    confettiController: _confettiController,
+                    blastDirectionality: BlastDirectionality.explosive,
+                    numberOfParticles: 20,
+                    gravity: 0.4,
+                    colors: const [
+                      AppColors.primary,
+                      Colors.yellow,
+                      AppColors.greenSuccessBright,
+                      AppColors.orange,
+                    ],
+                  ),
+                ),
+              ],
+            ),
+          );
         },
       ),
     );
diff --git a/flutter-app/lib/features/games/presentation/screens/hangman_screen.dart b/flutter-app/lib/features/games/presentation/screens/hangman_screen.dart
index c22d56f2..7f13d8d5 100644
--- a/flutter-app/lib/features/games/presentation/screens/hangman_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/hangman_screen.dart
@@ -5,11 +5,21 @@ import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/hangman_figure.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
+
+const _hangmanPowerUps = [
+  ShopItemEntity.effectRevealHint,
+  ShopItemEntity.effectTranslateHint,
+  ShopItemEntity.effectMistakeShield,
+  ShopItemEntity.effectExtraHeart,
+  ShopItemEntity.effectSkipToken,
+];
 
 /// Classic Hangman game screen.
 ///
@@ -35,7 +45,10 @@ class _HangmanScreenState extends State<HangmanScreen>
   bool _hint2Used = false;
   bool _hint3Used = false;
   String? _revealedHint;
+  String? _translationReveal;
   bool _isFinishing = false;
+  bool _shieldActive = false;
+  int _extraLives = 0;
 
   @override
   void initState() {
@@ -66,6 +79,8 @@ class _HangmanScreenState extends State<HangmanScreen>
   List<String> _wordLetters(HangmanGame game) =>
       game.word.toUpperCase().split('');
 
+  int _effectiveMaxLives(HangmanGame game) => game.maxLives + _extraLives;
+
   bool _isWordGuessed(HangmanGame game) {
     return _wordLetters(
       game,
@@ -78,10 +93,14 @@ class _HangmanScreenState extends State<HangmanScreen>
     setState(() {
       _guessedLetters.add(letter);
       if (!word.contains(letter)) {
-        _wrongGuesses++;
+        if (_shieldActive) {
+          _shieldActive = false;
+        } else {
+          _wrongGuesses++;
+        }
       }
     });
-    if (_wrongGuesses >= game.maxLives) {
+    if (_wrongGuesses >= _effectiveMaxLives(game)) {
       setState(() {
         _gameOver = true;
         _gameWon = false;
@@ -97,6 +116,50 @@ class _HangmanScreenState extends State<HangmanScreen>
     }
   }
 
+  void _onPowerUpUsed(String itemType, Map<String, dynamic> effects, HangmanGame game) {
+    if (_gameOver) return;
+    switch (itemType) {
+      case ShopItemEntity.effectRevealHint:
+        final word = _wordLetters(game);
+        final unguessed = word
+            .where((l) => l != ' ' && !_guessedLetters.contains(l))
+            .toList();
+        if (unguessed.isEmpty) return;
+        unguessed.shuffle();
+        setState(() => _guessedLetters.add(unguessed.first));
+        if (_isWordGuessed(game)) {
+          setState(() {
+            _gameOver = true;
+            _gameWon = true;
+          });
+          _confettiController.play();
+          _finishGame(game);
+        }
+        break;
+      case ShopItemEntity.effectTranslateHint:
+        setState(() => _translationReveal = game.vietnameseTranslation);
+        break;
+      case ShopItemEntity.effectMistakeShield:
+        setState(() => _shieldActive = true);
+        break;
+      case ShopItemEntity.effectExtraHeart:
+        final lives = (effects['lives'] as num?)?.toInt() ?? 1;
+        setState(() => _extraLives += lives);
+        break;
+      case ShopItemEntity.effectSkipToken:
+        setState(() {
+          _gameOver = true;
+          _gameWon = true;
+          for (final l in _wordLetters(game)) {
+            _guessedLetters.add(l);
+          }
+        });
+        _confettiController.play();
+        _finishGame(game);
+        break;
+    }
+  }
+
   void _useHint1(HangmanGame game) {
     if (_hint1Used) return;
     setState(() {
@@ -282,10 +345,10 @@ class _HangmanScreenState extends State<HangmanScreen>
                     padding: const EdgeInsets.only(right: 12),
                     child: Row(
                       children: List.generate(
-                        game.maxLives,
+                        _effectiveMaxLives(game),
                         (i) => Icon(
                           Icons.favorite,
-                          color: i < game.maxLives - _wrongGuesses
+                          color: i < _effectiveMaxLives(game) - _wrongGuesses
                               ? AppColors.errorBright
                               : AppColors.grey300,
                           size: 18,
@@ -297,6 +360,59 @@ class _HangmanScreenState extends State<HangmanScreen>
               ),
               body: Column(
                 children: [
+                  Padding(
+                    padding: const EdgeInsets.symmetric(
+                      horizontal: 16,
+                      vertical: 6,
+                    ),
+                    child: GamePowerUpTray(
+                      availableTypes: _hangmanPowerUps,
+                      enabled: !_gameOver,
+                      onUse: (type, effects) =>
+                          _onPowerUpUsed(type, effects, game),
+                    ),
+                  ),
+                  if (_shieldActive)
+                    const Padding(
+                      padding: EdgeInsets.only(bottom: 6),
+                      child: ActivePowerUpBadge(
+                        itemType: ShopItemEntity.effectMistakeShield,
+                        label: 'Shield Active',
+                      ),
+                    ),
+                  if (_translationReveal != null)
+                    Padding(
+                      padding: const EdgeInsets.symmetric(horizontal: 16),
+                      child: Container(
+                        padding: const EdgeInsets.all(10),
+                        margin: const EdgeInsets.only(bottom: 6),
+                        decoration: BoxDecoration(
+                          color: AppColors.purple.withValues(alpha: 0.12),
+                          borderRadius: BorderRadius.circular(10),
+                          border: Border.all(
+                            color: AppColors.purple.withValues(alpha: 0.4),
+                          ),
+                        ),
+                        child: Row(
+                          mainAxisAlignment: MainAxisAlignment.center,
+                          children: [
+                            const Icon(
+                              Icons.translate_rounded,
+                              size: 14,
+                              color: AppColors.purple,
+                            ),
+                            const SizedBox(width: 6),
+                            Flexible(
+                              child: Text(
+                                _translationReveal!,
+                                style: const TextStyle(fontSize: 13),
+                                textAlign: TextAlign.center,
+                              ),
+                            ),
+                          ],
+                        ),
+                      ),
+                    ),
                   // Category chip
                   Padding(
                     padding: const EdgeInsets.symmetric(
@@ -324,7 +440,8 @@ class _HangmanScreenState extends State<HangmanScreen>
                         Text(
                           'hangman.livesLeftLabel'.tr(
                             namedArgs: {
-                              'lives': '${game.maxLives - _wrongGuesses}',
+                              'lives':
+                                  '${_effectiveMaxLives(game) - _wrongGuesses}',
                             },
                           ),
                           style: TextStyle(
diff --git a/flutter-app/lib/features/games/presentation/screens/matching_game_screen.dart b/flutter-app/lib/features/games/presentation/screens/matching_game_screen.dart
index 094d678b..99f28456 100644
--- a/flutter-app/lib/features/games/presentation/screens/matching_game_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/matching_game_screen.dart
@@ -1,14 +1,25 @@
 import 'dart:async';
+import 'dart:math';
 import 'package:confetti/confetti.dart';
 import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
+
+const _matchingPowerUps = [
+  ShopItemEntity.effectTimeFreeze,
+  ShopItemEntity.effectExtraTime,
+  ShopItemEntity.effectPairSwap,
+  ShopItemEntity.effectLuckyClover,
+  ShopItemEntity.effectScoreMultiplier,
+];
 
 /// Matching Game screen.
 ///
@@ -33,6 +44,9 @@ class _MatchingGameScreenState extends State<MatchingGameScreen> {
   Map<String, _PairState> _matchState = {};
   int _correctCount = 0;
   bool _isFinishing = false;
+  bool _luckyCloverActive = false;
+  int _scoreMultiplier = 1;
+  final _random = Random();
 
   @override
   void initState() {
@@ -97,7 +111,13 @@ class _MatchingGameScreenState extends State<MatchingGameScreen> {
     final pair = game.pairs.firstWhere((p) => p.wordId == _selectedWord);
     final correctMatch = pair.matchText;
 
-    if (matchText == correctMatch) {
+    var matched = matchText == correctMatch;
+    if (!matched && _luckyCloverActive && _random.nextDouble() < 0.3) {
+      matched = true;
+      _luckyCloverActive = false;
+    }
+
+    if (matched) {
       _correctCount++;
       setState(() {
         _matchedIds.add(_selectedWord!);
@@ -129,6 +149,48 @@ class _MatchingGameScreenState extends State<MatchingGameScreen> {
     }
   }
 
+  void _onPowerUpUsed(String itemType, Map<String, dynamic> effects) {
+    final game = context.read<GamesProvider>().matching;
+    if (game == null) return;
+    switch (itemType) {
+      case ShopItemEntity.effectTimeFreeze:
+      case ShopItemEntity.effectExtraTime:
+        final seconds = (effects['seconds'] as num?)?.toInt() ?? 10;
+        setState(
+          () => _timeLeft = (_timeLeft + seconds).clamp(0, game.timerSeconds),
+        );
+        break;
+      case ShopItemEntity.effectPairSwap:
+        final remaining = game.pairs
+            .where((p) => !_matchedIds.contains(p.wordId))
+            .toList();
+        if (remaining.isEmpty) return;
+        final pair = remaining[_random.nextInt(remaining.length)];
+        _correctCount++;
+        setState(() {
+          _matchedIds.add(pair.wordId);
+          _matchState[pair.wordId] = _PairState.correct;
+          if (_selectedWord == pair.wordId) {
+            _selectedWord = null;
+            _selectedMatch = null;
+          }
+        });
+        if (_matchedIds.length == game.pairs.length) {
+          _confettiController.play();
+          _timer?.cancel();
+          Future.delayed(const Duration(milliseconds: 800), _finishGame);
+        }
+        break;
+      case ShopItemEntity.effectLuckyClover:
+        setState(() => _luckyCloverActive = true);
+        break;
+      case ShopItemEntity.effectScoreMultiplier:
+        final multiplier = (effects['multiplier'] as num?)?.toInt() ?? 2;
+        setState(() => _scoreMultiplier = multiplier);
+        break;
+    }
+  }
+
   Future<void> _abandonGame() async {
     if (_isFinishing) return;
     final confirmed = await showDialog<bool>(
@@ -179,7 +241,7 @@ class _MatchingGameScreenState extends State<MatchingGameScreen> {
     final elapsed = game.timerSeconds - _timeLeft;
     final xpResult = await provider.completeGame(
       gameType: GameType.matching,
-      score: _correctCount,
+      score: _correctCount * _scoreMultiplier,
       totalQuestions: total,
       correctAnswers: _correctCount,
       answers: [
@@ -198,7 +260,7 @@ class _MatchingGameScreenState extends State<MatchingGameScreen> {
           result: GameResult(
             gameType: GameType.matching,
             cefrLevel: provider.selectedLevel,
-            score: _correctCount,
+            score: _correctCount * _scoreMultiplier,
             totalQuestions: total,
             correctAnswers: _correctCount,
             xpEarned: xpResult?.xpAwarded ?? 0,
@@ -281,6 +343,24 @@ class _MatchingGameScreenState extends State<MatchingGameScreen> {
                     color: AppColors.greenSuccess,
                     minHeight: 4,
                   ),
+                  Padding(
+                    padding: const EdgeInsets.symmetric(
+                      horizontal: 12,
+                      vertical: 8,
+                    ),
+                    child: GamePowerUpTray(
+                      availableTypes: _matchingPowerUps,
+                      onUse: _onPowerUpUsed,
+                    ),
+                  ),
+                  if (_luckyCloverActive)
+                    const Padding(
+                      padding: EdgeInsets.only(bottom: 6),
+                      child: ActivePowerUpBadge(
+                        itemType: ShopItemEntity.effectLuckyClover,
+                        label: 'Lucky Clover Active',
+                      ),
+                    ),
                   Padding(
                     padding: const EdgeInsets.all(12),
                     child: Text(
diff --git a/flutter-app/lib/features/games/presentation/screens/spelling_bee_screen.dart b/flutter-app/lib/features/games/presentation/screens/spelling_bee_screen.dart
index 9a3e883a..c6789d77 100644
--- a/flutter-app/lib/features/games/presentation/screens/spelling_bee_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/spelling_bee_screen.dart
@@ -5,11 +5,20 @@ import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/di/service_locator.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/features/games/data/services/game_pronunciation_service.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
+
+const _spellingBeePowerUps = [
+  ShopItemEntity.effectMistakeShield,
+  ShopItemEntity.effectTranslateHint,
+  ShopItemEntity.effectSkipToken,
+  ShopItemEntity.effectScoreMultiplier,
+];
 
 /// Spelling Bee game screen.
 ///
@@ -34,6 +43,8 @@ class _SpellingBeeScreenState extends State<SpellingBeeScreen> {
   bool _isCorrect = false;
   bool _isFinishing = false;
   String? _audioErrorMessage;
+  String? _translationReveal;
+  int _scoreMultiplier = 1;
   final Map<String, String> _submittedAnswers = {};
 
   @override
@@ -63,10 +74,35 @@ class _SpellingBeeScreenState extends State<SpellingBeeScreen> {
       _answered = false;
       _isCorrect = false;
       _audioErrorMessage = null;
+      _translationReveal = null;
       _inputController.clear();
     });
   }
 
+  void _onPowerUpUsed(String itemType, Map<String, dynamic> effects) {
+    if (_answered) return;
+    final game = context.read<GamesProvider>().spellingBee;
+    if (game == null) return;
+    final word = game.words[_wordIndex];
+    switch (itemType) {
+      case ShopItemEntity.effectMistakeShield:
+        setState(() => _playsLeft += 1);
+        break;
+      case ShopItemEntity.effectTranslateHint:
+        setState(() => _translationReveal = word.vietnameseTranslation);
+        break;
+      case ShopItemEntity.effectSkipToken:
+        _submittedAnswers[word.wordId] = '';
+        setState(() => _answered = true);
+        Future.delayed(const Duration(milliseconds: 300), _nextWord);
+        break;
+      case ShopItemEntity.effectScoreMultiplier:
+        final multiplier = (effects['multiplier'] as num?)?.toInt() ?? 2;
+        setState(() => _scoreMultiplier = multiplier);
+        break;
+    }
+  }
+
   Future<void> _playAudio() async {
     if (_playsLeft <= 0 || _pronunciationService.isPlaying) return;
     final game = context.read<GamesProvider>().spellingBee;
@@ -164,7 +200,7 @@ class _SpellingBeeScreenState extends State<SpellingBeeScreen> {
     final game = provider.spellingBee!;
     final xpResult = await provider.completeGame(
       gameType: GameType.spellingBee,
-      score: _correctCount,
+      score: _correctCount * _scoreMultiplier,
       totalQuestions: game.words.length,
       correctAnswers: _correctCount,
       answers: [
@@ -183,7 +219,7 @@ class _SpellingBeeScreenState extends State<SpellingBeeScreen> {
           result: GameResult(
             gameType: GameType.spellingBee,
             cefrLevel: provider.selectedLevel,
-            score: _correctCount,
+            score: _correctCount * _scoreMultiplier,
             totalQuestions: game.words.length,
             correctAnswers: _correctCount,
             xpEarned: xpResult?.xpAwarded ?? 0,
@@ -259,12 +295,52 @@ class _SpellingBeeScreenState extends State<SpellingBeeScreen> {
                   color: AppColors.primary,
                   minHeight: 4,
                 ),
+                Padding(
+                  padding: const EdgeInsets.symmetric(
+                    horizontal: 16,
+                    vertical: 8,
+                  ),
+                  child: GamePowerUpTray(
+                    availableTypes: _spellingBeePowerUps,
+                    enabled: !_answered,
+                    onUse: _onPowerUpUsed,
+                  ),
+                ),
                 Expanded(
                   child: SingleChildScrollView(
                     padding: const EdgeInsets.all(24),
                     child: Column(
                       children: [
                         const SizedBox(height: 20),
+                        if (_translationReveal != null)
+                          Container(
+                            width: double.infinity,
+                            margin: const EdgeInsets.only(bottom: 12),
+                            padding: const EdgeInsets.all(12),
+                            decoration: BoxDecoration(
+                              color: AppColors.purple.withValues(alpha: 0.12),
+                              borderRadius: BorderRadius.circular(8),
+                              border: Border.all(
+                                color: AppColors.purple.withValues(alpha: 0.4),
+                              ),
+                            ),
+                            child: Row(
+                              children: [
+                                const Icon(
+                                  Icons.translate_rounded,
+                                  size: 16,
+                                  color: AppColors.purple,
+                                ),
+                                const SizedBox(width: 8),
+                                Expanded(
+                                  child: Text(
+                                    _translationReveal!,
+                                    style: const TextStyle(fontSize: 13),
+                                  ),
+                                ),
+                              ],
+                            ),
+                          ),
                         // Audio error banner
                         if (_audioErrorMessage != null)
                           Container(
diff --git a/flutter-app/lib/features/games/presentation/screens/word_scramble_screen.dart b/flutter-app/lib/features/games/presentation/screens/word_scramble_screen.dart
index 8f86f69a..870cbc03 100644
--- a/flutter-app/lib/features/games/presentation/screens/word_scramble_screen.dart
+++ b/flutter-app/lib/features/games/presentation/screens/word_scramble_screen.dart
@@ -5,12 +5,23 @@ import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/letter_tile.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 
+const _wordScramblePowerUps = [
+  ShopItemEntity.effectTimeFreeze,
+  ShopItemEntity.effectExtraTime,
+  ShopItemEntity.effectSkipToken,
+  ShopItemEntity.effectRevealHint,
+  ShopItemEntity.effectTranslateHint,
+  ShopItemEntity.effectScoreMultiplier,
+];
+
 /// Word Scramble game screen.
 ///
 /// Presents one word at a time with shuffled letter tiles. The player taps
@@ -34,6 +45,8 @@ class _WordScrambleScreenState extends State<WordScrambleScreen> {
   bool _wordAnswered = false;
   bool _isFinishing = false;
   String? _xpPopup;
+  String? _translationReveal;
+  int _scoreMultiplier = 1;
   final Map<String, String> _submittedAnswers = {};
 
   // Letter tile state
@@ -78,11 +91,55 @@ class _WordScrambleScreenState extends State<WordScrambleScreen> {
       _showHint = false;
       _wordAnswered = false;
       _xpPopup = null;
+      _translationReveal = null;
       _timeLeft = game.timerSeconds;
     });
     _startTimer(game.timerSeconds);
   }
 
+  void _onPowerUpUsed(String itemType, Map<String, dynamic> effects) {
+    final game = context.read<GamesProvider>().wordScramble;
+    if (game == null || _wordAnswered) return;
+    final word = game.words[_currentWordIndex];
+    switch (itemType) {
+      case ShopItemEntity.effectTimeFreeze:
+      case ShopItemEntity.effectExtraTime:
+        final seconds = (effects['seconds'] as num?)?.toInt() ?? 10;
+        setState(
+          () => _timeLeft = (_timeLeft + seconds).clamp(0, game.timerSeconds),
+        );
+        break;
+      case ShopItemEntity.effectSkipToken:
+        _timer?.cancel();
+        _skipWord();
+        break;
+      case ShopItemEntity.effectRevealHint:
+        _revealLetter(word);
+        break;
+      case ShopItemEntity.effectTranslateHint:
+        setState(() => _translationReveal = word.vietnameseTranslation);
+        break;
+      case ShopItemEntity.effectScoreMultiplier:
+        final multiplier = (effects['multiplier'] as num?)?.toInt() ?? 2;
+        setState(() => _scoreMultiplier = multiplier);
+        break;
+    }
+  }
+
+  void _revealLetter(ScrambleWord word) {
+    final correctLetters = word.word.toUpperCase().split('');
+    final emptySlot = _answerSlots.indexWhere((s) => s == null);
+    if (emptySlot == -1) return;
+    final neededLetter = correctLetters[emptySlot];
+    final poolIdx = _poolLetters.indexWhere((l) => l == neededLetter);
+    if (poolIdx == -1) return;
+    setState(() {
+      _poolLetters[poolIdx] = '';
+      _answerSlots[emptySlot] = neededLetter;
+    });
+    _checkAnswer();
+  }
+
   void _startTimer(int seconds) {
     _timer?.cancel();
     _timeLeft = seconds;
@@ -141,7 +198,7 @@ class _WordScrambleScreenState extends State<WordScrambleScreen> {
       setState(() {
         _slotCorrect = List<bool>.filled(_answerSlots.length, true);
         _wordAnswered = true;
-        _xpPopup = '+${word.xpValue} XP';
+        _xpPopup = '+${word.xpValue * _scoreMultiplier} XP';
       });
       _confettiController.play();
       Future.delayed(const Duration(milliseconds: 1400), _nextWord);
@@ -349,11 +406,24 @@ class _WordScrambleScreenState extends State<WordScrambleScreen> {
                       ),
                       child: Column(
                         children: [
+                          GamePowerUpTray(
+                            availableTypes: _wordScramblePowerUps,
+                            enabled: !_wordAnswered,
+                            onUse: _onPowerUpUsed,
+                          ),
+                          const SizedBox(height: 8),
                           // XP popup
                           if (_xpPopup != null) _XpPopup(text: _xpPopup!),
                           const SizedBox(height: 4),
                           // Hint area
                           _HintCard(word: word, showHint: _showHint),
+                          if (_translationReveal != null)
+                            Padding(
+                              padding: const EdgeInsets.only(top: 8),
+                              child: _TranslationBanner(
+                                text: _translationReveal!,
+                              ),
+                            ),
                           const SizedBox(height: 20),
                           // Answer slots
                           Text(
@@ -527,6 +597,43 @@ class _TimerDisplay extends StatelessWidget {
   }
 }
 
+class _TranslationBanner extends StatelessWidget {
+  final String text;
+  const _TranslationBanner({required this.text});
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      width: double.infinity,
+      padding: const EdgeInsets.all(12),
+      decoration: BoxDecoration(
+        color: AppColors.purple.withValues(alpha: 0.12),
+        borderRadius: BorderRadius.circular(12),
+        border: Border.all(color: AppColors.purple.withValues(alpha: 0.4)),
+      ),
+      child: Row(
+        children: [
+          const Icon(
+            Icons.translate_rounded,
+            size: 14,
+            color: AppColors.purple,
+          ),
+          const SizedBox(width: 6),
+          Expanded(
+            child: Text(
+              text,
+              style: TextStyle(
+                fontSize: 13,
+                color: Theme.of(context).colorScheme.onSurface,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
 class _HintCard extends StatelessWidget {
   final ScrambleWord word;
   final bool showHint;
diff --git a/flutter-app/lib/features/games/presentation/widgets/daily_challenge_card.dart b/flutter-app/lib/features/games/presentation/widgets/daily_challenge_card.dart
index e6bdf92b..808e5bcc 100644
--- a/flutter-app/lib/features/games/presentation/widgets/daily_challenge_card.dart
+++ b/flutter-app/lib/features/games/presentation/widgets/daily_challenge_card.dart
@@ -10,11 +10,13 @@ import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart'
 class DailyChallengeCard extends StatelessWidget {
   final DailyChallenge challenge;
   final VoidCallback onTap;
+  final bool allowCompletedTap;
 
   const DailyChallengeCard({
     super.key,
     required this.challenge,
     required this.onTap,
+    this.allowCompletedTap = false,
   });
 
   /// Map apiKey → matching GameType, returning null when unknown.
@@ -32,7 +34,7 @@ class DailyChallengeCard extends StatelessWidget {
     final completed = challenge.completed;
 
     return GestureDetector(
-      onTap: completed ? null : onTap,
+      onTap: completed && !allowCompletedTap ? null : onTap,
       child: AnimatedContainer(
         duration: const Duration(milliseconds: 250),
         decoration: BoxDecoration(
diff --git a/flutter-app/lib/features/games/presentation/widgets/daily_challenge_mapper.dart b/flutter-app/lib/features/games/presentation/widgets/daily_challenge_mapper.dart
new file mode 100644
index 00000000..3a32f8b1
--- /dev/null
+++ b/flutter-app/lib/features/games/presentation/widgets/daily_challenge_mapper.dart
@@ -0,0 +1,45 @@
+import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/daily_challenge_entity.dart';
+
+GameType gameTypeForDailyChallenge(DailyChallengeEntity challenge) {
+  final haystack = [
+    challenge.category,
+    challenge.title,
+    challenge.description,
+    challenge.icon,
+  ].join(' ').toLowerCase();
+
+  if (haystack.contains('grammar')) return GameType.grammarQuiz;
+  if (haystack.contains('listening') || haystack.contains('blank')) {
+    return GameType.fillBlank;
+  }
+  if (haystack.contains('voice') ||
+      haystack.contains('speak') ||
+      haystack.contains('pronunciation')) {
+    return GameType.spellingBee;
+  }
+  if (haystack.contains('match')) return GameType.matching;
+  if (haystack.contains('hangman')) return GameType.hangman;
+  if (haystack.contains('vocab') || haystack.contains('word')) {
+    return GameType.wordScramble;
+  }
+  return GameType.fillBlank;
+}
+
+DailyChallenge toGameDailyChallenge(DailyChallengeEntity challenge) {
+  final gameType = gameTypeForDailyChallenge(challenge);
+  final description = challenge.description.trim().isNotEmpty
+      ? challenge.description.trim()
+      : challenge.title.trim();
+
+  return DailyChallenge(
+    gameType: gameType.apiKey,
+    description: description.isNotEmpty
+        ? description
+        : 'Complete today challenge',
+    targetScore: challenge.target,
+    bonusMultiplier: challenge.xpReward >= 40 ? 2 : 1,
+    completed: challenge.isCompleted,
+    resetsAt: challenge.expiresAt,
+  );
+}
diff --git a/flutter-app/lib/features/games/presentation/widgets/game_powerup_tray.dart b/flutter-app/lib/features/games/presentation/widgets/game_powerup_tray.dart
new file mode 100644
index 00000000..93117a1f
--- /dev/null
+++ b/flutter-app/lib/features/games/presentation/widgets/game_powerup_tray.dart
@@ -0,0 +1,208 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/game_icon.dart';
+import 'package:lexilingo_app/features/gamification/presentation/providers/gamification_provider.dart';
+
+/// Horizontal tray of owned in-game power-ups (Time Freeze, Skip Token,
+/// Magnifying Glass, Shield, ...) for a mini-game screen to consume mid-play.
+///
+/// Only power-ups the player actually owns (quantity > 0) are shown, filtered
+/// to [availableTypes] — the subset of the 10 power-up `item_type`s that make
+/// sense for that particular game. Tapping consumes one via
+/// [GamificationProvider.useItemWithEffects] and, on success, calls [onUse]
+/// with the item type and its effects payload so the screen can apply the
+/// gameplay effect (e.g. add seconds to a timer).
+class GamePowerUpTray extends StatelessWidget {
+  final List<String> availableTypes;
+  final void Function(String itemType, Map<String, dynamic> effects) onUse;
+  final bool enabled;
+
+  const GamePowerUpTray({
+    super.key,
+    required this.availableTypes,
+    required this.onUse,
+    this.enabled = true,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<GamificationProvider>(
+      builder: (context, provider, _) {
+        final entries = availableTypes
+            .map((type) => (type: type, owned: provider.powerUpsOf(type)))
+            .where((entry) => entry.owned.isNotEmpty)
+            .toList();
+        if (entries.isEmpty) return const SizedBox.shrink();
+
+        return SizedBox(
+          height: 52,
+          child: ListView.separated(
+            scrollDirection: Axis.horizontal,
+            itemCount: entries.length,
+            separatorBuilder: (_, __) => const SizedBox(width: 8),
+            itemBuilder: (context, index) {
+              final entry = entries[index];
+              final quantity = entry.owned.fold<int>(
+                0,
+                (sum, inv) => sum + inv.quantity,
+              );
+              return _PowerUpButton(
+                itemType: entry.type,
+                inventoryId: entry.owned.first.id,
+                itemName: entry.owned.first.item.name,
+                quantity: quantity,
+                enabled: enabled,
+                onUsed: onUse,
+              );
+            },
+          ),
+        );
+      },
+    );
+  }
+}
+
+class _PowerUpButton extends StatefulWidget {
+  final String itemType;
+  final String inventoryId;
+  final String itemName;
+  final int quantity;
+  final bool enabled;
+  final void Function(String itemType, Map<String, dynamic> effects) onUsed;
+
+  const _PowerUpButton({
+    required this.itemType,
+    required this.inventoryId,
+    required this.itemName,
+    required this.quantity,
+    required this.enabled,
+    required this.onUsed,
+  });
+
+  @override
+  State<_PowerUpButton> createState() => _PowerUpButtonState();
+}
+
+class _PowerUpButtonState extends State<_PowerUpButton> {
+  bool _isUsing = false;
+
+  Future<void> _handleTap() async {
+    if (_isUsing || !widget.enabled) return;
+    setState(() => _isUsing = true);
+    final effects = await context
+        .read<GamificationProvider>()
+        .useItemWithEffects(widget.inventoryId);
+    if (!mounted) return;
+    setState(() => _isUsing = false);
+    if (effects != null) {
+      widget.onUsed(widget.itemType, effects);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final icon = gamePowerUpIcons[widget.itemType];
+    final canUse = widget.enabled && !_isUsing;
+
+    return Opacity(
+      opacity: canUse ? 1.0 : 0.5,
+      child: Tooltip(
+        message: widget.itemName,
+        child: GestureDetector(
+          onTap: canUse ? _handleTap : null,
+          child: Container(
+            width: 48,
+            height: 48,
+            decoration: BoxDecoration(
+              color: AppColors.purple.withValues(alpha: 0.12),
+              borderRadius: BorderRadius.circular(12),
+              border: Border.all(
+                color: AppColors.purple.withValues(alpha: 0.35),
+              ),
+            ),
+            child: Stack(
+              clipBehavior: Clip.none,
+              children: [
+                Center(
+                  child: _isUsing
+                      ? SizedBox(
+                          width: 18,
+                          height: 18,
+                          child: CircularProgressIndicator(
+                            strokeWidth: 2,
+                            color: AppColors.purple,
+                          ),
+                        )
+                      : (icon != null
+                          ? AppGameIcon(icon, size: 26)
+                          : const Icon(Icons.bolt, size: 26)),
+                ),
+                Positioned(
+                  right: -4,
+                  top: -4,
+                  child: Container(
+                    padding: const EdgeInsets.symmetric(
+                      horizontal: 5,
+                      vertical: 1,
+                    ),
+                    decoration: BoxDecoration(
+                      color: AppColors.purple,
+                      borderRadius: BorderRadius.circular(8),
+                    ),
+                    child: Text(
+                      '${widget.quantity}',
+                      style: const TextStyle(
+                        fontSize: 10,
+                        fontWeight: FontWeight.bold,
+                        color: Colors.white,
+                      ),
+                    ),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+/// Persistent pill shown while an "armed" power-up (one that waits for the
+/// next relevant game event rather than applying instantly, e.g. Mistake
+/// Shield or Lucky Clover) is still active, so the player knows it's primed.
+class ActivePowerUpBadge extends StatelessWidget {
+  final String itemType;
+  final String label;
+
+  const ActivePowerUpBadge({super.key, required this.itemType, required this.label});
+
+  @override
+  Widget build(BuildContext context) {
+    final icon = gamePowerUpIcons[itemType];
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
+      decoration: BoxDecoration(
+        color: AppColors.purple.withValues(alpha: 0.12),
+        borderRadius: BorderRadius.circular(20),
+        border: Border.all(color: AppColors.purple.withValues(alpha: 0.35)),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          if (icon != null) AppGameIcon(icon, size: 16),
+          const SizedBox(width: 6),
+          Text(
+            label,
+            style: const TextStyle(
+              fontSize: 12,
+              fontWeight: FontWeight.bold,
+              color: AppColors.purple,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/gamification/data/datasources/gamification_remote_data_source.dart b/flutter-app/lib/features/gamification/data/datasources/gamification_remote_data_source.dart
index 809c7e21..2e1a1a94 100644
--- a/flutter-app/lib/features/gamification/data/datasources/gamification_remote_data_source.dart
+++ b/flutter-app/lib/features/gamification/data/datasources/gamification_remote_data_source.dart
@@ -8,7 +8,10 @@ abstract class GamificationRemoteDataSource {
   Future<List<dynamic>> getShopItems();
   Future<bool> purchaseItem(String itemId, {int quantity = 1});
   Future<Map<String, dynamic>> getInventory();
-  Future<bool> useItem(String inventoryId);
+
+  /// Uses an inventory item; returns its `effects_applied` payload on
+  /// success (e.g. `{"seconds": 10}` for a Time Freeze), or null on failure.
+  Future<Map<String, dynamic>?> useItem(String inventoryId);
   Future<Map<String, dynamic>?> equipAvatar(String inventoryId);
   Future<Map<String, dynamic>> getLeaderboard(String league);
   Future<Map<String, dynamic>> getLeagueStatus();
@@ -79,12 +82,16 @@ class GamificationRemoteDataSourceImpl implements GamificationRemoteDataSource {
   }
 
   @override
-  Future<bool> useItem(String inventoryId) async {
+  Future<Map<String, dynamic>?> useItem(String inventoryId) async {
     final r = await _apiClient.post(
       '/gamification/inventory/use',
       body: {'inventory_id': inventoryId},
     );
-    return _ok(r);
+    if (!_ok(r)) return null;
+    final d = _data(r);
+    if (d is! Map<String, dynamic>) return {};
+    final effects = d['effects_applied'];
+    return effects is Map<String, dynamic> ? effects : {};
   }
 
   @override
diff --git a/flutter-app/lib/features/gamification/data/repositories/gamification_repository_impl.dart b/flutter-app/lib/features/gamification/data/repositories/gamification_repository_impl.dart
index 7f6d8176..9f760d4c 100644
--- a/flutter-app/lib/features/gamification/data/repositories/gamification_repository_impl.dart
+++ b/flutter-app/lib/features/gamification/data/repositories/gamification_repository_impl.dart
@@ -50,7 +50,8 @@ class GamificationRepositoryImpl implements GamificationRepository {
   }
 
   @override
-  Future<bool> useItem(String inventoryId) => _remote.useItem(inventoryId);
+  Future<Map<String, dynamic>?> useItem(String inventoryId) =>
+      _remote.useItem(inventoryId);
 
   @override
   Future<String?> equipAvatar(String inventoryId) async {
diff --git a/flutter-app/lib/features/gamification/domain/entities/shop_item.dart b/flutter-app/lib/features/gamification/domain/entities/shop_item.dart
index 79cabf1f..d3b8ce45 100644
--- a/flutter-app/lib/features/gamification/domain/entities/shop_item.dart
+++ b/flutter-app/lib/features/gamification/domain/entities/shop_item.dart
@@ -44,6 +44,32 @@ class ShopItemEntity extends Equatable {
   static const String effectHeartRefill = 'heart_refill';
   static const String effectAvatar = 'avatar';
 
+  /// In-game power-up effect types — instant, single-use consumables
+  /// applied directly inside a mini-game session (see GameIcon mappings).
+  static const String effectTimeFreeze = 'time_freeze';
+  static const String effectExtraTime = 'extra_time';
+  static const String effectSkipToken = 'skip_token';
+  static const String effectRevealHint = 'reveal_hint';
+  static const String effectTranslateHint = 'translate_hint';
+  static const String effectMistakeShield = 'mistake_shield';
+  static const String effectExtraHeart = 'extra_heart';
+  static const String effectLuckyClover = 'lucky_clover';
+  static const String effectScoreMultiplier = 'score_multiplier';
+  static const String effectPairSwap = 'pair_swap';
+
+  static const List<String> gamePowerUpEffectTypes = [
+    effectTimeFreeze,
+    effectExtraTime,
+    effectSkipToken,
+    effectRevealHint,
+    effectTranslateHint,
+    effectMistakeShield,
+    effectExtraHeart,
+    effectLuckyClover,
+    effectScoreMultiplier,
+    effectPairSwap,
+  ];
+
   bool get isPowerUp => category == categoryPowerUps;
   bool get isCosmetic => category == categoryCosmetics;
   bool get isBoost => category == categoryBoosts;
@@ -92,6 +118,7 @@ class ShopItemEntity extends Equatable {
   }
 
   static String _categoryFor(String? itemType) {
+    if (gamePowerUpEffectTypes.contains(itemType)) return categoryPowerUps;
     switch (itemType) {
       case effectDoubleXP:
         return categoryBoosts;
diff --git a/flutter-app/lib/features/gamification/domain/entities/wallet.dart b/flutter-app/lib/features/gamification/domain/entities/wallet.dart
index 9eb70f50..4f99995c 100644
--- a/flutter-app/lib/features/gamification/domain/entities/wallet.dart
+++ b/flutter-app/lib/features/gamification/domain/entities/wallet.dart
@@ -23,10 +23,18 @@ class WalletEntity extends Equatable {
       id: json['id'] ?? '',
       userId: json['user_id'] ?? json['userId'] ?? '',
       gems: json['gems'] ?? 0,
-      totalEarned: json['total_earned'] ?? json['totalEarned'] ?? 0,
-      totalSpent: json['total_spent'] ?? json['totalSpent'] ?? 0,
-      lastUpdated: json['last_updated'] != null
-          ? DateTime.parse(json['last_updated'])
+      totalEarned:
+          json['total_gems_earned'] ??
+          json['total_earned'] ??
+          json['totalEarned'] ??
+          0,
+      totalSpent:
+          json['total_gems_spent'] ??
+          json['total_spent'] ??
+          json['totalSpent'] ??
+          0,
+      lastUpdated: (json['updated_at'] ?? json['last_updated']) != null
+          ? DateTime.parse(json['updated_at'] ?? json['last_updated'])
           : null,
     );
   }
@@ -61,7 +69,7 @@ class WalletTransactionEntity extends Equatable {
   factory WalletTransactionEntity.fromJson(Map<String, dynamic> json) {
     return WalletTransactionEntity(
       id: json['id'] ?? '',
-      type: json['type'] ?? 'earn',
+      type: json['transaction_type'] ?? json['type'] ?? 'earn',
       amount: json['amount'] ?? 0,
       description: json['description'] ?? '',
       referenceType: json['reference_type'] ?? json['referenceType'],
diff --git a/flutter-app/lib/features/gamification/domain/repositories/gamification_repository.dart b/flutter-app/lib/features/gamification/domain/repositories/gamification_repository.dart
index cfd9aa31..debdb0df 100644
--- a/flutter-app/lib/features/gamification/domain/repositories/gamification_repository.dart
+++ b/flutter-app/lib/features/gamification/domain/repositories/gamification_repository.dart
@@ -12,7 +12,9 @@ abstract class GamificationRepository {
   Future<List<ShopItemEntity>> getShopItems();
   Future<bool> purchaseItem(String itemId, {int quantity = 1});
   Future<List<InventoryItemEntity>> getInventory();
-  Future<bool> useItem(String inventoryId);
+  /// Uses an inventory item; returns its applied effects payload on
+  /// success, or null on failure.
+  Future<Map<String, dynamic>?> useItem(String inventoryId);
   Future<String?> equipAvatar(String inventoryId);
   Future<LeaderboardEntity> getLeaderboard(String league);
   Future<LeagueStatusEntity> getLeagueStatus();
diff --git a/flutter-app/lib/features/gamification/presentation/providers/gamification_provider.dart b/flutter-app/lib/features/gamification/presentation/providers/gamification_provider.dart
index 640cc755..2fb221b1 100644
--- a/flutter-app/lib/features/gamification/presentation/providers/gamification_provider.dart
+++ b/flutter-app/lib/features/gamification/presentation/providers/gamification_provider.dart
@@ -66,6 +66,13 @@ class GamificationProvider extends ChangeNotifier {
       .where((i) => i.isActive && !i.isExpired && i.expiresAt != null)
       .toList();
 
+  /// Owned, usable in-game power-ups of a given [itemType] (e.g.
+  /// [ShopItemEntity.effectTimeFreeze]), used by the games feature's
+  /// power-up tray to show what the player can consume mid-game.
+  List<InventoryItemEntity> powerUpsOf(String itemType) => _inventory
+      .where((i) => i.item.effectType == itemType && i.quantity > 0)
+      .toList();
+
   bool get isLoadingInventory => _isLoadingInventory;
   String? get inventoryError => _inventoryError;
   bool ownsItem(String shopItemId) =>
@@ -215,13 +222,22 @@ class GamificationProvider extends ChangeNotifier {
   }
 
   Future<bool> useItem(String inventoryId) async {
+    final effects = await useItemWithEffects(inventoryId);
+    return effects != null;
+  }
+
+  /// Uses an inventory item and returns its applied effects payload
+  /// (e.g. `{"seconds": 10}` for a Time Freeze), or null on failure.
+  /// Used by the games feature's power-up tray to apply the right
+  /// gameplay effect after a successful consume.
+  Future<Map<String, dynamic>?> useItemWithEffects(String inventoryId) async {
     try {
-      final ok = await _repository.useItem(inventoryId);
-      if (ok) await loadInventory();
-      return ok;
+      final effects = await _repository.useItem(inventoryId);
+      if (effects != null) await loadInventory();
+      return effects;
     } catch (e) {
       debugPrint('Error using item: $e');
-      return false;
+      return null;
     }
   }
 
diff --git a/flutter-app/lib/features/gamification/presentation/screens/league_ceremony_screen.dart b/flutter-app/lib/features/gamification/presentation/screens/league_ceremony_screen.dart
index 8b9efe21..68346b46 100644
--- a/flutter-app/lib/features/gamification/presentation/screens/league_ceremony_screen.dart
+++ b/flutter-app/lib/features/gamification/presentation/screens/league_ceremony_screen.dart
@@ -1,14 +1,17 @@
+import 'dart:math' as math;
+
+import 'package:confetti/confetti.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:lexilingo_app/core/widgets/lottie_animation_widget.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
 import 'package:lexilingo_app/features/gamification/presentation/widgets/rank_asset_icon.dart';
 
 enum LeagueCeremonyType { promotion, demotion }
 
 /// Full-screen ceremony shown when the user's league changes at week end.
 ///
-/// Promoted: star-burst Lottie + league color gradient + upbeat copy.
-/// Demoted: muted animation + neutral tone + motivational copy.
+/// Promoted: confetti burst + radar-pulse badge + league color gradient.
+/// Demoted: muted gradient + neutral tone + motivational copy, no confetti.
 class LeagueCeremonyScreen extends StatefulWidget {
   final String newLeague;
   final String? previousLeague;
@@ -56,195 +59,322 @@ class LeagueCeremonyScreen extends StatefulWidget {
 
 class _LeagueCeremonyScreenState extends State<LeagueCeremonyScreen>
     with TickerProviderStateMixin {
-  late final AnimationController _badgeScale;
-  late final AnimationController _textSlide;
-  late final Animation<double> _scaleAnim;
-  late final Animation<Offset> _slideAnim;
+  late final AnimationController _sequence;
+  late final AnimationController _ringPulse;
+  late final Animation<double> _ringFade;
+  late final Animation<double> _badgeScale;
+  late final Animation<double> _headerFade;
+  late final Animation<double> _titleFade;
+  late final Animation<Offset> _titleSlide;
+  late final Animation<double> _subtitleFade;
+  late final Animation<double> _buttonFade;
+  late final Animation<Offset> _buttonSlide;
+  ConfettiController? _confetti;
 
   @override
   void initState() {
     super.initState();
-    _badgeScale = AnimationController(
+    final isPromotion = widget.type == LeagueCeremonyType.promotion;
+
+    _sequence = AnimationController(
       vsync: this,
-      duration: const Duration(milliseconds: 700),
+      duration: const Duration(milliseconds: 1100),
     );
-    _textSlide = AnimationController(
-      vsync: this,
-      duration: const Duration(milliseconds: 500),
+
+    _ringFade = CurvedAnimation(
+      parent: _sequence,
+      curve: const Interval(0.0, 0.4, curve: Curves.easeOut),
+    );
+    _badgeScale = CurvedAnimation(
+      parent: _sequence,
+      curve: const Interval(0.05, 0.55, curve: Curves.easeOutBack),
+    );
+    _headerFade = CurvedAnimation(
+      parent: _sequence,
+      curve: const Interval(0.0, 0.3, curve: Curves.easeOut),
     );
-    _scaleAnim = Tween<double>(begin: 0.0, end: 1.0).animate(
-      CurvedAnimation(parent: _badgeScale, curve: Curves.elasticOut),
+    final titleCurve = CurvedAnimation(
+      parent: _sequence,
+      curve: const Interval(0.35, 0.75, curve: Curves.easeOutCubic),
     );
-    _slideAnim = Tween<Offset>(
+    _titleFade = titleCurve;
+    _titleSlide = Tween<Offset>(
+      begin: const Offset(0, 0.25),
+      end: Offset.zero,
+    ).animate(titleCurve);
+    _subtitleFade = CurvedAnimation(
+      parent: _sequence,
+      curve: const Interval(0.45, 0.85, curve: Curves.easeOut),
+    );
+    final buttonCurve = CurvedAnimation(
+      parent: _sequence,
+      curve: const Interval(0.55, 1.0, curve: Curves.easeOutCubic),
+    );
+    _buttonFade = buttonCurve;
+    _buttonSlide = Tween<Offset>(
       begin: const Offset(0, 0.3),
       end: Offset.zero,
-    ).animate(CurvedAnimation(parent: _textSlide, curve: Curves.easeOutCubic));
+    ).animate(buttonCurve);
+
+    _ringPulse = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 1800),
+    );
+
+    _sequence.forward();
 
-    Future.delayed(const Duration(milliseconds: 200), () {
-      if (mounted) _badgeScale.forward();
-    });
-    Future.delayed(const Duration(milliseconds: 500), () {
-      if (mounted) _textSlide.forward();
-    });
+    if (isPromotion) {
+      _ringPulse.repeat();
+      _confetti = ConfettiController(
+        duration: const Duration(milliseconds: 1200),
+      );
+      Future.delayed(const Duration(milliseconds: 150), () {
+        if (mounted) _confetti?.play();
+      });
+    }
   }
 
   @override
   void dispose() {
-    _badgeScale.dispose();
-    _textSlide.dispose();
+    _sequence.dispose();
+    _ringPulse.dispose();
+    _confetti?.dispose();
     super.dispose();
   }
 
+  /// Picks a legible text color for a solid [background] fill,
+  /// since pale league colors (silver, gold, platinum) wash out white text.
+  Color _onColor(Color background) {
+    return background.computeLuminance() > 0.5
+        ? AppColors.textDark
+        : Colors.white;
+  }
+
   @override
   Widget build(BuildContext context) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
     final visualData = rankVisualDataFor(widget.newLeague.toLowerCase());
     final leagueColor = isDark ? visualData.colorDark : visualData.color;
     final isPromotion = widget.type == LeagueCeremonyType.promotion;
+    final buttonTextColor = _onColor(leagueColor);
 
     return Scaffold(
       backgroundColor: Colors.transparent,
       body: Stack(
         alignment: Alignment.center,
         children: [
-          // Gradient backdrop
+          // Layered gradient backdrop
           Container(
             decoration: BoxDecoration(
               gradient: RadialGradient(
-                center: Alignment.center,
-                radius: 1.2,
+                center: const Alignment(0, -0.2),
+                radius: 1.3,
                 colors: [
-                  leagueColor.withValues(alpha: isPromotion ? 0.3 : 0.12),
-                  Colors.black.withValues(alpha: 0.85),
+                  leagueColor.withValues(alpha: isPromotion ? 0.35 : 0.12),
+                  const Color(0xFF0B0E14).withValues(alpha: 0.92),
+                  const Color(0xFF05070A),
                 ],
+                stops: const [0.0, 0.6, 1.0],
               ),
             ),
           ),
 
-          // Lottie: star-burst for promotion, heartbeat for demotion
-          if (isPromotion)
-            const Positioned.fill(
-              child: IgnorePointer(
-                child: LottieAnimationWidget.starBurst(),
+          // Contained confetti burst from the top — only for promotions.
+          if (isPromotion && _confetti != null)
+            Align(
+              alignment: Alignment.topCenter,
+              child: ConfettiWidget(
+                confettiController: _confetti!,
+                blastDirection: math.pi / 2,
+                blastDirectionality: BlastDirectionality.explosive,
+                maxBlastForce: 12,
+                minBlastForce: 6,
+                emissionFrequency: 0.06,
+                numberOfParticles: 18,
+                gravity: 0.25,
+                shouldLoop: false,
+                colors: [leagueColor, Colors.white, AppColors.gold],
               ),
             ),
 
-          // Content
           SafeArea(
             child: Padding(
               padding: const EdgeInsets.symmetric(horizontal: 32),
               child: Column(
                 mainAxisAlignment: MainAxisAlignment.center,
                 children: [
-                  // Header
                   FadeTransition(
-                    opacity: _textSlide,
-                    child: Text(
-                      isPromotion ? 'Promoted!' : 'Keep Going!',
-                      style: TextStyle(
-                        fontSize: 18,
-                        fontWeight: FontWeight.w700,
-                        color: leagueColor,
-                        letterSpacing: 1,
-                      ),
+                    opacity: _headerFade,
+                    child: _StatusChip(
+                      label: isPromotion ? 'PROMOTED' : 'DEMOTED',
+                      color: leagueColor,
+                      icon: isPromotion
+                          ? Icons.arrow_upward_rounded
+                          : Icons.arrow_downward_rounded,
                     ),
                   ),
-                  const SizedBox(height: 28),
+                  const SizedBox(height: 32),
 
-                  // League badge
-                  ScaleTransition(
-                    scale: _scaleAnim,
-                    child: Container(
-                      width: 120,
-                      height: 120,
-                      decoration: BoxDecoration(
-                        shape: BoxShape.circle,
-                        color: leagueColor.withValues(alpha: 0.15),
-                        border: Border.all(
-                          color: leagueColor.withValues(alpha: 0.5),
-                          width: 3,
-                        ),
-                        boxShadow: [
-                          BoxShadow(
-                            color: leagueColor.withValues(alpha: 0.35),
-                            blurRadius: 40,
-                            spreadRadius: 8,
+                  SizedBox(
+                    width: 160,
+                    height: 160,
+                    child: Stack(
+                      alignment: Alignment.center,
+                      children: [
+                        if (isPromotion)
+                          AnimatedBuilder(
+                            animation: _ringPulse,
+                            builder: (context, _) {
+                              final t = _ringPulse.value;
+                              return Opacity(
+                                opacity: (1 - t) * 0.6,
+                                child: Transform.scale(
+                                  scale: 1.0 + t * 0.45,
+                                  child: Container(
+                                    width: 132,
+                                    height: 132,
+                                    decoration: BoxDecoration(
+                                      shape: BoxShape.circle,
+                                      border: Border.all(
+                                        color: leagueColor,
+                                        width: 2,
+                                      ),
+                                    ),
+                                  ),
+                                ),
+                              );
+                            },
+                          ),
+                        FadeTransition(
+                          opacity: _ringFade,
+                          child: ScaleTransition(
+                            scale: _badgeScale,
+                            child: Container(
+                              width: 124,
+                              height: 124,
+                              decoration: BoxDecoration(
+                                shape: BoxShape.circle,
+                                gradient: RadialGradient(
+                                  colors: [
+                                    leagueColor.withValues(alpha: 0.28),
+                                    leagueColor.withValues(alpha: 0.08),
+                                  ],
+                                ),
+                                border: Border.all(
+                                  color: leagueColor.withValues(alpha: 0.7),
+                                  width: 3,
+                                ),
+                                boxShadow: [
+                                  BoxShadow(
+                                    color: leagueColor.withValues(alpha: 0.4),
+                                    blurRadius: 36,
+                                    spreadRadius: 4,
+                                  ),
+                                ],
+                              ),
+                              child: Image.asset(
+                                visualData.assetPath,
+                                width: 76,
+                                height: 76,
+                                fit: BoxFit.contain,
+                                errorBuilder: (_, __, ___) => Icon(
+                                  Icons.military_tech_rounded,
+                                  size: 64,
+                                  color: leagueColor,
+                                ),
+                              ),
+                            ),
                           ),
-                        ],
-                      ),
-                      child: Image.asset(
-                        visualData.assetPath,
-                        width: 72,
-                        height: 72,
-                        fit: BoxFit.contain,
-                        errorBuilder: (_, __, ___) => Icon(
-                          Icons.military_tech_rounded,
-                          size: 64,
-                          color: leagueColor,
                         ),
-                      ),
+                      ],
                     ),
                   ),
-                  const SizedBox(height: 28),
+                  const SizedBox(height: 32),
 
-                  // League name
                   SlideTransition(
-                    position: _slideAnim,
+                    position: _titleSlide,
                     child: FadeTransition(
-                      opacity: _textSlide,
-                      child: Column(
-                        children: [
-                          Text(
-                            _leagueName(widget.newLeague),
-                            style: TextStyle(
-                              fontSize: 34,
-                              fontWeight: FontWeight.w900,
-                              color: Colors.white,
-                              letterSpacing: -0.5,
-                            ),
-                          ),
-                          const SizedBox(height: 10),
-                          Text(
-                            isPromotion
-                                ? _promotionSubtitle(widget.previousLeague)
-                                : _demotionSubtitle(widget.newLeague),
-                            textAlign: TextAlign.center,
-                            style: TextStyle(
-                              fontSize: 15,
-                              color: Colors.white.withValues(alpha: 0.75),
-                              height: 1.5,
-                            ),
-                          ),
-                        ],
+                      opacity: _titleFade,
+                      child: Text(
+                        _leagueName(widget.newLeague),
+                        style: const TextStyle(
+                          fontSize: 36,
+                          fontWeight: FontWeight.w900,
+                          color: Colors.white,
+                          letterSpacing: -0.5,
+                        ),
                       ),
                     ),
                   ),
-                  const SizedBox(height: 48),
+                  const SizedBox(height: 12),
+
+                  FadeTransition(
+                    opacity: _subtitleFade,
+                    child: Text(
+                      isPromotion
+                          ? _promotionSubtitle(widget.previousLeague)
+                          : _demotionSubtitle(widget.newLeague),
+                      textAlign: TextAlign.center,
+                      style: TextStyle(
+                        fontSize: 15,
+                        color: Colors.white.withValues(alpha: 0.72),
+                        height: 1.5,
+                      ),
+                    ),
+                  ),
+                  const SizedBox(height: 44),
 
-                  // CTA button
                   SlideTransition(
-                    position: _slideAnim,
+                    position: _buttonSlide,
                     child: FadeTransition(
-                      opacity: _textSlide,
+                      opacity: _buttonFade,
                       child: SizedBox(
                         width: double.infinity,
-                        child: FilledButton(
-                          onPressed: () {
-                            Navigator.of(context).pop();
-                            widget.onContinue();
-                          },
-                          style: FilledButton.styleFrom(
-                            backgroundColor: leagueColor,
-                            padding: const EdgeInsets.symmetric(vertical: 16),
-                            shape: RoundedRectangleBorder(
-                              borderRadius: BorderRadius.circular(16),
+                        child: DecoratedBox(
+                          decoration: BoxDecoration(
+                            borderRadius: BorderRadius.circular(16),
+                            gradient: LinearGradient(
+                              begin: Alignment.topCenter,
+                              end: Alignment.bottomCenter,
+                              colors: [
+                                leagueColor,
+                                Color.lerp(leagueColor, Colors.black, 0.25)!,
+                              ],
                             ),
+                            boxShadow: [
+                              BoxShadow(
+                                color: leagueColor.withValues(alpha: 0.45),
+                                blurRadius: 20,
+                                offset: const Offset(0, 8),
+                              ),
+                            ],
                           ),
-                          child: Text(
-                            isPromotion ? 'Claim Your Spot!' : 'Fight Back!',
-                            style: const TextStyle(
-                              fontWeight: FontWeight.w700,
-                              fontSize: 16,
+                          child: Material(
+                            color: Colors.transparent,
+                            borderRadius: BorderRadius.circular(16),
+                            child: InkWell(
+                              borderRadius: BorderRadius.circular(16),
+                              onTap: () {
+                                Navigator.of(context).pop();
+                                widget.onContinue();
+                              },
+                              child: Padding(
+                                padding: const EdgeInsets.symmetric(
+                                  vertical: 16,
+                                ),
+                                child: Center(
+                                  child: Text(
+                                    isPromotion
+                                        ? 'Claim Your Spot!'
+                                        : 'Fight Back!',
+                                    style: TextStyle(
+                                      fontWeight: FontWeight.w700,
+                                      fontSize: 16,
+                                      color: buttonTextColor,
+                                    ),
+                                  ),
+                                ),
+                              ),
                             ),
                           ),
                         ),
@@ -271,3 +401,43 @@ class _LeagueCeremonyScreenState extends State<LeagueCeremonyScreen>
   String _demotionSubtitle(String current) =>
       'You dropped to ${_leagueName(current)} League.\nBut every champion starts from the bottom — come back stronger!';
 }
+
+class _StatusChip extends StatelessWidget {
+  final String label;
+  final Color color;
+  final IconData icon;
+
+  const _StatusChip({
+    required this.label,
+    required this.color,
+    required this.icon,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 7),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: 0.18),
+        borderRadius: BorderRadius.circular(20),
+        border: Border.all(color: color.withValues(alpha: 0.5)),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(icon, size: 14, color: color),
+          const SizedBox(width: 6),
+          Text(
+            label,
+            style: TextStyle(
+              fontSize: 12,
+              fontWeight: FontWeight.w700,
+              color: color,
+              letterSpacing: 1.2,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/gamification/presentation/widgets/shop_item_card.dart b/flutter-app/lib/features/gamification/presentation/widgets/shop_item_card.dart
index 5416f9aa..861ac821 100644
--- a/flutter-app/lib/features/gamification/presentation/widgets/shop_item_card.dart
+++ b/flutter-app/lib/features/gamification/presentation/widgets/shop_item_card.dart
@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/widgets/game_icon.dart';
 import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
@@ -291,6 +292,8 @@ class ShopItemCard extends StatelessWidget {
       );
     }
 
+    final gameIcon = gamePowerUpIcons[item.effectType];
+
     IconData icon;
     switch (item.effectType) {
       case ShopItemEntity.effectStreakFreeze:
@@ -333,7 +336,11 @@ class ShopItemCard extends StatelessWidget {
           ),
         ],
       ),
-      child: Icon(icon, color: AppColors.surfaceLight, size: 32),
+      child: Center(
+        child: gameIcon != null
+            ? AppGameIcon(gameIcon, size: 32, fallbackColor: AppColors.surfaceLight)
+            : Icon(icon, color: AppColors.surfaceLight, size: 32),
+      ),
     );
   }
 
diff --git a/flutter-app/lib/features/home/presentation/pages/home_page.dart b/flutter-app/lib/features/home/presentation/pages/home_page.dart
index 96311bd8..587e526a 100644
--- a/flutter-app/lib/features/home/presentation/pages/home_page.dart
+++ b/flutter-app/lib/features/home/presentation/pages/home_page.dart
@@ -1,31 +1,26 @@
-import 'package:cached_network_image/cached_network_image.dart';
 import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
-import 'package:lexilingo_app/core/theme/app_theme.dart';
 import 'package:lexilingo_app/core/widgets/widgets.dart';
-import 'package:lexilingo_app/core/widgets/glassmorphic_components.dart'
-    as glass;
 import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
-import 'package:lexilingo_app/features/home/presentation/widgets/home_ui_components.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/enrolled_courses_section.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/featured_courses_section.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/home_header.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/home_skeleton_loading.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/level_and_daily_goal_row.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/quick_actions_grid.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/section_title.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/streak_card_section.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_section.dart';
 import 'package:lexilingo_app/features/user/presentation/providers/user_provider.dart';
 import 'package:lexilingo_app/features/auth/presentation/providers/auth_provider.dart';
-import 'package:lexilingo_app/features/course/domain/entities/course_entity.dart';
-import 'package:lexilingo_app/features/course/presentation/screens/course_detail_screen.dart';
-import 'package:lexilingo_app/features/course/presentation/utils/course_thumbnail_resolver.dart';
-import 'package:lexilingo_app/features/vocabulary/presentation/pages/vocab_library_page.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/widgets/daily_review_card.dart';
 import 'package:lexilingo_app/features/progress/presentation/providers/streak_provider.dart';
-import 'package:lexilingo_app/features/progress/presentation/widgets/points_calendar_dialog.dart';
 import 'package:lexilingo_app/features/progress/presentation/widgets/daily_challenges_widget.dart';
 import 'package:lexilingo_app/features/progress/presentation/widgets/daily_reward_dialog.dart';
 import 'package:lexilingo_app/features/level/level.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/level_up_dialog.dart';
 import 'package:lexilingo_app/features/gamification/presentation/widgets/rank_up_dialog.dart';
-import 'package:lexilingo_app/features/notifications/presentation/providers/notification_provider.dart';
-import 'package:lexilingo_app/features/notifications/presentation/pages/notifications_page.dart';
-import 'package:lexilingo_app/features/books/presentation/providers/book_provider.dart';
-import 'package:lexilingo_app/features/user/presentation/providers/settings_provider.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/widgets/word_of_day_card.dart';
 import 'package:lexilingo_app/features/gamification/presentation/widgets/active_boosts_bar.dart';
 
@@ -58,11 +53,11 @@ class _HomePageNewState extends State<HomePageNew> {
       });
       // Listen for level-up events triggered by fetchLevelFull
       _levelProvider?.addListener(_onLevelProviderChange);
-      
+
       // Setup streak provider listener
       _streakProvider = context.read<StreakProvider>();
       _streakProvider?.addListener(_onStreakProviderChange);
-      
+
       // Load streak data here (after auth token is ready) instead of relying
       // on the race-prone call in main.dart that fires before authentication.
       _streakProvider?.loadStreak();
@@ -83,7 +78,9 @@ class _HomePageNewState extends State<HomePageNew> {
     }
 
     final streak = streakProvider.streak;
-    if (streak != null && streak.isDailyRewardAvailable && !_isDailyRewardDialogShowing) {
+    if (streak != null &&
+        streak.isDailyRewardAvailable &&
+        !_isDailyRewardDialogShowing) {
       _isDailyRewardDialogShowing = true;
       WidgetsBinding.instance.addPostFrameCallback((_) {
         if (!mounted) return;
@@ -138,7 +135,7 @@ class _HomePageNewState extends State<HomePageNew> {
           builder: (context, homeProvider, userProvider, authProvider, child) {
             if (homeProvider.isLoading &&
                 homeProvider.featuredCourses.isEmpty) {
-              return _buildSkeletonLoading();
+              return const HomeSkeletonLoading();
             }
 
             if (homeProvider.errorMessage != null) {
@@ -155,1969 +152,87 @@ class _HomePageNewState extends State<HomePageNew> {
               ]),
               child: SingleChildScrollView(
                 physics: const AlwaysScrollableScrollPhysics(),
-                child: StaggeredList(
-                  itemDelay: const Duration(milliseconds: 55),
-                  itemDuration: const Duration(milliseconds: 460),
-                  slideOffset: 22,
-                  children: [
-                    Align(
-                      alignment: Alignment.centerLeft,
-                      child: _buildHeader(context, homeProvider, authProvider),
-                    ),
-                    Padding(
-                      padding: const EdgeInsets.only(top: 12),
-                      child: _buildStreakCard(context, homeProvider),
-                    ),
-                    Padding(
-                      padding: const EdgeInsets.only(top: 12),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          _buildSectionTitle(context, 'home.quickActions'.tr()),
-                          const SizedBox(height: 8),
-                          _buildQuickActionsHorizontal(context),
-                        ],
-                      ),
-                    ),
-                    const Padding(
-                      padding: EdgeInsets.only(top: 12),
-                      child: ActiveBoostsBar(),
-                    ),
-                    const Padding(
-                      padding: EdgeInsets.only(top: 12),
-                      child: WordOfDayCard(),
-                    ),
-                    Padding(
-                      padding: const EdgeInsets.only(top: 12),
-                      child: _buildLevelAndDailyGoalRow(context, homeProvider),
-                    ),
-                    const Padding(
-                      padding: EdgeInsets.fromLTRB(16, 12, 16, 0),
-                      child: DailyChallengesCard(),
-                    ),
-                    const Padding(
-                      padding: EdgeInsets.fromLTRB(16, 12, 16, 0),
-                      child: DailyReviewCard(),
-                    ),
-                    Padding(
-                      padding: const EdgeInsets.only(top: 12),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          _buildSectionTitle(
-                            context,
-                            'home.continueLearningSection'.tr(),
-                          ),
-                          const SizedBox(height: 8),
-                          _buildEnrolledCoursesSection(context, homeProvider),
-                        ],
-                      ),
-                    ),
-                    Padding(
-                      padding: const EdgeInsets.only(top: 12, bottom: 24),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          _buildSectionTitle(
-                            context,
-                            'home.featuredCourses'.tr(),
-                          ),
-                          const SizedBox(height: 8),
-                          _buildFeaturedCourses(context, homeProvider),
-                        ],
-                      ),
-                    ),
-                  ],
-                ),
-              ),
-            );
-          },
-        ),
-      ),
-    );
-  }
-
-  Widget _buildHeader(
-    BuildContext context,
-    HomeProvider homeProvider,
-    AuthProvider authProvider,
-  ) {
-    // Get user display name from AuthProvider
-    final user = authProvider.currentUser;
-    final displayName = user?.displayName.isNotEmpty == true
-        ? user!.displayName
-        : user?.username ?? 'profile.guestUser'.tr();
-
-    return Consumer2<NotificationProvider, LevelProvider>(
-      builder: (context, notificationProvider, levelProvider, child) {
-        final totalXP = levelProvider.levelStatus.totalXP;
-        return PersonalizedGreetingHeader(
-          userName: displayName,
-          totalXP: totalXP,
-          avatarUrl: user?.avatarUrl,
-          notificationCount: notificationProvider.unreadCount,
-          onNotificationTap: () {
-            Navigator.push(
-              context,
-              MaterialPageRoute(builder: (_) => const NotificationsPage()),
-            );
-          },
-          onAvatarTap: () {
-            // Navigate to profile or settings
-          },
-        );
-      },
-    );
-  }
-
-  Widget _buildStreakCard(BuildContext context, HomeProvider provider) {
-    return Consumer<StreakProvider>(
-      builder: (context, streakProvider, child) {
-        final streak = streakProvider.streak;
-        final currentStreak = streak?.currentStreak ?? provider.streakDays;
-        final longestStreak = streak?.longestStreak ?? 0;
-        final isActiveToday = streak?.isActiveToday ?? false;
-
-        return Padding(
-          padding: const EdgeInsets.symmetric(horizontal: 16.0),
-          child: AnimatedStreakCard(
-            streakDays: currentStreak,
-            longestStreak: longestStreak,
-            isActiveToday: isActiveToday,
-            weeklyActivity: streak?.weeklyActivity,
-            weeklyProgressPercentages: provider.weeklyProgress.weekProgress
-                .map((day) => day.progressPercentage)
-                .toList(growable: false),
-            onTap: () {
-              if (streak != null) {
-                showPointsCalendarDialog(context, streak);
-              }
-            },
-          ),
-        );
-      },
-    );
-  }
-
-  Widget _buildLevelAndDailyGoalRow(
-    BuildContext context,
-    HomeProvider provider,
-  ) {
-    return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: 16.0),
-      child: LayoutBuilder(
-        builder: (context, constraints) {
-          final isNarrow = constraints.maxWidth < 360;
-
-          if (isNarrow) {
-            return Column(
-              children: [
-                SizedBox(height: 148, child: LevelProgressCard(compact: true)),
-                const SizedBox(height: 12),
-                SizedBox(
-                  height: 148,
-                  child: _buildDailyGoalCard(
-                    context,
-                    provider,
-                    compact: true,
-                    margin: EdgeInsets.zero,
-                  ),
-                ),
-              ],
-            );
-          }
-
-          return Row(
-            crossAxisAlignment: CrossAxisAlignment.start,
-            children: [
-              Expanded(
-                flex: 6,
-                child: SizedBox(
-                  height: 148,
-                  child: LevelProgressCard(compact: true),
-                ),
-              ),
-              const SizedBox(width: 12),
-              Expanded(
-                flex: 4,
-                child: SizedBox(
-                  height: 148,
-                  child: _buildDailyGoalCard(
-                    context,
-                    provider,
-                    compact: true,
-                    margin: EdgeInsets.zero,
-                  ),
-                ),
-              ),
-            ],
-          );
-        },
-      ),
-    );
-  }
-
-  Widget _buildDailyGoalCard(
-    BuildContext context,
-    HomeProvider provider, {
-    bool compact = false,
-    EdgeInsetsGeometry? margin,
-  }) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    // Use user-configured daily goal from settings; fall back to HomeProvider.
-    final goalXP = context.read<SettingsProvider>().dailyGoalXP;
-    final earnedXP = provider.dailyXP;
-    final percentage = goalXP > 0 ? (earnedXP / goalXP).clamp(0.0, 1.0) : 0.0;
-    final isCompleted = percentage >= 1.0;
-    final colorScheme = Theme.of(context).colorScheme;
-    final accent = AppColorRoles.primary(isDark);
-    final accentDeep = AppColorRoles.primaryDeep(isDark);
-    final surfaceBg = colorScheme.surfaceContainerHighest;
-    final compactBg = isCompleted
-        ? AppColors.greenSuccessBright.withValues(alpha: 0.10)
-        : accent.withValues(alpha: 0.07);
-    final cardPadding = compact ? 14.0 : 20.0;
-    final ringSize = compact ? 58.0 : 70.0;
-    final ringStroke = compact ? 5.0 : 6.0;
-    final titleFontSize = compact ? 16.0 : null;
-    final valueFontSize = compact ? 18.0 : null;
-    final chipFontSize = compact ? 11.0 : 12.0;
-    final badgeIconSize = compact ? 16.0 : 18.0;
-    final ringValueFontSize = compact ? 12.0 : 14.0;
-
-    final borderRadius = BorderRadius.circular(compact ? 16 : 20);
-
-    return Material(
-      color: Colors.transparent,
-      child: Padding(
-        padding: margin ?? const EdgeInsets.symmetric(horizontal: 16),
-        child: InkWell(
-          onTap: () => _showDailyGoalSheet(context, provider),
-          borderRadius: borderRadius,
-          child: Ink(
-            padding: EdgeInsets.all(cardPadding),
-            decoration: BoxDecoration(
-              color: compact ? compactBg : surfaceBg,
-              borderRadius: borderRadius,
-              border: Border.all(
-                color: isCompleted
-                    ? AppColors.greenSuccessBright.withValues(alpha: 0.3)
-                    : accent.withValues(alpha: 0.35),
-              ),
-            ),
-            child: compact
-                ? Column(
-                    crossAxisAlignment: CrossAxisAlignment.center,
-                    mainAxisAlignment: MainAxisAlignment.center,
-                    children: [
-                      Row(
-                        mainAxisAlignment: MainAxisAlignment.center,
-                        children: [
-                          Container(
-                            padding: const EdgeInsets.all(5),
-                            decoration: BoxDecoration(
-                              color: colorScheme.surface,
-                              borderRadius: BorderRadius.circular(8),
-                            ),
-                            child: isCompleted
-                                ? AppGameIcon(
-                                    GameIcon.trophy,
-                                    size: badgeIconSize,
-                                    fallbackColor: AppColors.greenSuccessBright,
-                                  )
-                                : AppGameIcon(
-                                    GameIcon.bolt,
-                                    size: badgeIconSize,
-                                    fallbackColor: accent,
-                                  ),
-                          ),
-                          const SizedBox(width: 8),
-                          Flexible(
-                            child: Text(
-                              'home.dailyGoal'.tr(),
-                              maxLines: 1,
-                              overflow: TextOverflow.ellipsis,
-                              style: Theme.of(context).textTheme.titleSmall
-                                  ?.copyWith(
-                                    fontWeight: FontWeight.bold,
-                                    fontSize: 15,
-                                    color: isCompleted
-                                        ? AppColors.greenSuccess
-                                        : accentDeep,
-                                  ),
-                            ),
-                          ),
-                        ],
-                      ),
-                      const SizedBox(height: 10),
-                      Expanded(
-                        child: Center(
-                          child: Container(
-                            decoration: BoxDecoration(
-                              shape: BoxShape.circle,
-                              color: colorScheme.surface,
-                            ),
-                            child: glass.AnimatedProgressRing(
-                              progress: percentage.clamp(0.0, 1.0),
-                              size: ringSize + 10,
-                              strokeWidth: ringStroke,
-                              gradientColors: isCompleted
-                                  ? const [
-                                      AppColors.greenSuccessBright,
-                                      AppColors.greenSuccess,
-                                    ]
-                                  : AppColorRoles.primaryGradient(isDark),
-                              child: Column(
-                                mainAxisAlignment: MainAxisAlignment.center,
-                                children: [
-                                  if (isCompleted)
-                                    const AppGameIcon(
-                                      GameIcon.checkmark,
-                                      size: 20,
-                                      fallbackColor:
-                                          AppColors.greenSuccessBright,
-                                    )
-                                  else
-                                    Text(
-                                      '${(percentage * 100).toInt()}%',
-                                      style: TextStyle(
-                                        fontSize: ringValueFontSize,
-                                        fontWeight: FontWeight.bold,
-                                        color: accent,
-                                      ),
-                                    ),
-                                ],
-                              ),
-                            ),
-                          ),
+                child: Center(
+                  child: ConstrainedBox(
+                    constraints: const BoxConstraints(maxWidth: 1180),
+                    child: StaggeredList(
+                      itemDelay: const Duration(milliseconds: 55),
+                      itemDuration: const Duration(milliseconds: 460),
+                      slideOffset: 22,
+                      children: [
+                        const Align(
+                          alignment: Alignment.centerLeft,
+                          child: HomeHeader(),
                         ),
-                      ),
-                      const SizedBox(height: 8),
-                      Text(
-                        '$earnedXP/$goalXP XP',
-                        maxLines: 1,
-                        overflow: TextOverflow.ellipsis,
-                        style: Theme.of(context).textTheme.titleMedium
-                            ?.copyWith(
-                              fontWeight: FontWeight.bold,
-                              fontSize: 16,
-                              color: isCompleted
-                                  ? AppColors.greenSuccessBright
-                                  : accent,
-                            ),
-                      ),
-                    ],
-                  )
-                : Row(
-                    children: [
-                      // Animated Progress Ring
-                      Container(
-                        padding: const EdgeInsets.all(4),
-                        decoration: BoxDecoration(
-                          shape: BoxShape.circle,
-                          color: colorScheme.surface,
+                        const Padding(
+                          padding: EdgeInsets.only(top: 12),
+                          child: StreakCardSection(),
                         ),
-                        child: glass.AnimatedProgressRing(
-                          progress: percentage.clamp(0.0, 1.0),
-                          size: ringSize,
-                          strokeWidth: ringStroke,
-                          gradientColors: isCompleted
-                              ? const [
-                                  AppColors.greenSuccessBright,
-                                  AppColors.greenSuccess,
-                                ]
-                              : const [AppColors.primary, AppColors.primary],
+                        Padding(
+                          padding: const EdgeInsets.only(top: 12),
                           child: Column(
-                            mainAxisSize: MainAxisSize.min,
+                            crossAxisAlignment: CrossAxisAlignment.start,
                             children: [
-                              if (isCompleted)
-                                const AppGameIcon(
-                                  GameIcon.checkmark,
-                                  size: 22,
-                                  fallbackColor: AppColors.greenSuccessBright,
-                                )
-                              else
-                                Text(
-                                  '${(percentage * 100).toInt()}%',
-                                  style: TextStyle(
-                                    fontSize: ringValueFontSize,
-                                    fontWeight: FontWeight.bold,
-                                    color: isCompleted
-                                        ? AppColors.greenSuccessBright
-                                        : AppColors.primary,
-                                  ),
-                                ),
+                              SectionTitle(title: 'home.quickActions'.tr()),
+                              const SizedBox(height: 8),
+                              const QuickActionsGrid(),
                             ],
                           ),
                         ),
-                      ),
-                      SizedBox(width: compact ? 12 : 20),
-                      // Info
-                      Expanded(
-                        child: Column(
-                          crossAxisAlignment: CrossAxisAlignment.start,
-                          children: [
-                            Row(
-                              children: [
-                                Container(
-                                  padding: EdgeInsets.all(compact ? 5 : 6),
-                                  decoration: BoxDecoration(
-                                    color: colorScheme.surface,
-                                    borderRadius: BorderRadius.circular(8),
-                                  ),
-                                  child: isCompleted
-                                      ? AppGameIcon(
-                                          GameIcon.trophy,
-                                          size: badgeIconSize,
-                                          fallbackColor:
-                                              AppColors.greenSuccessBright,
-                                        )
-                                      : AppGameIcon(
-                                          GameIcon.bolt,
-                                          size: badgeIconSize,
-                                          fallbackColor: accent,
-                                        ),
-                                ),
-                                const SizedBox(width: 8),
-                                Expanded(
-                                  child: Text(
-                                    'home.dailyXpGoal'.tr(),
-                                    maxLines: 1,
-                                    overflow: TextOverflow.ellipsis,
-                                    style: Theme.of(context)
-                                        .textTheme
-                                        .titleMedium
-                                        ?.copyWith(
-                                          fontWeight: FontWeight.bold,
-                                          fontSize: titleFontSize,
-                                          color: isCompleted
-                                              ? AppColors.greenSuccess
-                                              : accentDeep,
-                                        ),
-                                  ),
-                                ),
-                              ],
-                            ),
-                            SizedBox(height: compact ? 6 : 8),
-                            Text(
-                              '$earnedXP/$goalXP XP',
-                              style: Theme.of(context).textTheme.headlineSmall
-                                  ?.copyWith(
-                                    fontWeight: FontWeight.bold,
-                                    fontSize: valueFontSize,
-                                    color: isCompleted
-                                        ? AppColors.greenSuccessBright
-                                        : accent,
-                                  ),
-                            ),
-                            SizedBox(height: compact ? 2 : 4),
-                            Container(
-                              padding: EdgeInsets.symmetric(
-                                horizontal: compact ? 8 : 10,
-                                vertical: compact ? 3 : 4,
-                              ),
-                              decoration: BoxDecoration(
-                                color: colorScheme.surface,
-                                borderRadius: BorderRadius.circular(12),
-                              ),
-                              child: Row(
-                                mainAxisSize: MainAxisSize.min,
-                                children: [
-                                  isCompleted
-                                      ? AppGameIcon(
-                                          GameIcon.giftBox,
-                                          size: 14,
-                                          fallbackColor:
-                                              AppColors.greenSuccessBright,
-                                        )
-                                      : Icon(
-                                          Icons.trending_up,
-                                          size: 14,
-                                          color: accent,
-                                        ),
-                                  const SizedBox(width: 4),
-                                  Text(
-                                    isCompleted
-                                        ? 'home.goalCompleted'.tr()
-                                        : 'home.keepGoing'.tr(),
-                                    style: TextStyle(
-                                      fontSize: chipFontSize,
-                                      fontWeight: FontWeight.w600,
-                                      color: isCompleted
-                                          ? AppColors.greenSuccessBright
-                                          : accent,
-                                    ),
-                                  ),
-                                ],
-                              ),
-                            ),
-                          ],
+                        const TodayPlanSection(),
+                        const Padding(
+                          padding: EdgeInsets.only(top: 12),
+                          child: ActiveBoostsBar(),
                         ),
-                      ),
-                    ],
-                  ),
-          ),
-        ),
-      ),
-    );
-  }
-
-  Future<void> _showDailyGoalSheet(
-    BuildContext context,
-    HomeProvider homeProvider,
-  ) async {
-    final settings = context.read<SettingsProvider>();
-    final settingsState = settings.settings;
-
-    if (settingsState == null) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(content: Text('home.dailyGoalSettingsPending'.tr())),
-      );
-      return;
-    }
-
-    await showModalBottomSheet<void>(
-      context: context,
-      isScrollControlled: true,
-      backgroundColor: Colors.transparent,
-      builder: (sheetContext) {
-        final isDark = Theme.of(sheetContext).brightness == Brightness.dark;
-        final colorScheme = Theme.of(sheetContext).colorScheme;
-        final primaryColor = AppColorRoles.primary(isDark);
-
-        return Consumer<SettingsProvider>(
-          builder: (sheetContext, settingsProvider, _) {
-            return Container(
-              padding: const EdgeInsets.fromLTRB(24, 12, 24, 32),
-              decoration: BoxDecoration(
-                color: Theme.of(sheetContext).scaffoldBackgroundColor,
-                borderRadius: const BorderRadius.vertical(
-                  top: Radius.circular(24),
-                ),
-              ),
-              child: SingleChildScrollView(
-                child: Column(
-                  mainAxisSize: MainAxisSize.min,
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  children: [
-                    Center(
-                      child: Container(
-                        width: 40,
-                        height: 4,
-                        margin: const EdgeInsets.only(bottom: 20),
-                        decoration: BoxDecoration(
-                          color: colorScheme.outlineVariant,
-                          borderRadius: BorderRadius.circular(999),
+                        const Padding(
+                          padding: EdgeInsets.only(top: 12),
+                          child: WordOfDayCard(),
                         ),
-                      ),
-                    ),
-                    Text(
-                      'home.dailyGoal'.tr(),
-                      style: Theme.of(sheetContext).textTheme.headlineSmall
-                          ?.copyWith(fontWeight: FontWeight.w800),
-                    ),
-                    const SizedBox(height: 6),
-                    Text(
-                      'home.dailyGoalDescription'.tr(),
-                      style: Theme.of(sheetContext).textTheme.bodyMedium
-                          ?.copyWith(color: AppColorRoles.textMuted(isDark)),
-                    ),
-                    const SizedBox(height: 16),
-                    Container(
-                      width: double.infinity,
-                      padding: const EdgeInsets.all(16),
-                      decoration: BoxDecoration(
-                        gradient: LinearGradient(
-                          colors: [
-                            primaryColor,
-                            primaryColor.withValues(alpha: 0.72),
-                          ],
-                        ),
-                        borderRadius: BorderRadius.circular(18),
-                      ),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          Text(
-                            '${homeProvider.dailyXP}/${settingsProvider.dailyGoalXP} XP',
-                            style: Theme.of(sheetContext)
-                                .textTheme
-                                .headlineSmall
-                                ?.copyWith(
-                                  color: colorScheme.onPrimary,
-                                  fontWeight: FontWeight.w800,
-                                ),
-                          ),
-                          const SizedBox(height: 4),
-                          Text(
-                            'settings.goal_progress'.tr(
-                              namedArgs: {
-                                'percent':
-                                    '${(homeProvider.dailyProgressPercentage * 100).toInt()}',
-                              },
-                            ),
-                            style: Theme.of(sheetContext).textTheme.bodyMedium
-                                ?.copyWith(
-                                  color: colorScheme.onPrimary.withValues(
-                                    alpha: 0.88,
-                                  ),
-                                ),
-                          ),
-                        ],
-                      ),
-                    ),
-                    const SizedBox(height: 16),
-                    ...SettingsProvider.dailyGoalPresets.map((goal) {
-                      final xp = goal['xp'] as int;
-                      final isSelected = settingsProvider.dailyGoalXP == xp;
-
-                      return Padding(
-                        padding: const EdgeInsets.only(bottom: 10),
-                        child: InkWell(
-                          borderRadius: BorderRadius.circular(16),
-                          onTap: () async {
-                            await settingsProvider.updateDailyGoal(xp);
-                            if (!sheetContext.mounted) return;
-
-                            if (settingsProvider.error == null) {
-                              homeProvider.updateDailyGoalTarget(xp);
-                              Navigator.of(sheetContext).pop();
-                              ScaffoldMessenger.of(context).showSnackBar(
-                                SnackBar(
-                                  content: Text(
-                                    'settings.goal_updated'.tr(
-                                      namedArgs: {'xp': '$xp'},
-                                    ),
-                                  ),
-                                ),
-                              );
-                            } else {
-                              ScaffoldMessenger.of(sheetContext).showSnackBar(
-                                SnackBar(
-                                  content: Text(settingsProvider.error!),
-                                ),
-                              );
-                            }
-                          },
-                          child: AnimatedContainer(
-                            duration: const Duration(milliseconds: 180),
-                            padding: const EdgeInsets.symmetric(
-                              horizontal: 14,
-                              vertical: 14,
-                            ),
-                            decoration: BoxDecoration(
-                              color: isSelected
-                                  ? primaryColor.withValues(alpha: 0.12)
-                                  : colorScheme.surfaceContainerHighest,
-                              borderRadius: BorderRadius.circular(16),
-                              border: Border.all(
-                                color: isSelected
-                                    ? primaryColor
-                                    : colorScheme.outlineVariant,
-                                width: isSelected ? 2 : 1,
-                              ),
-                            ),
-                            child: Row(
-                              children: [
-                                Container(
-                                  width: 42,
-                                  height: 42,
-                                  decoration: BoxDecoration(
-                                    color: isSelected
-                                        ? primaryColor
-                                        : primaryColor.withValues(alpha: 0.12),
-                                    borderRadius: BorderRadius.circular(12),
-                                  ),
-                                  child: Icon(
-                                    goal['icon'] as IconData,
-                                    color: isSelected
-                                        ? colorScheme.onPrimary
-                                        : primaryColor,
-                                  ),
-                                ),
-                                const SizedBox(width: 12),
-                                Expanded(
-                                  child: Column(
-                                    crossAxisAlignment:
-                                        CrossAxisAlignment.start,
-                                    children: [
-                                      Text(
-                                        '${(goal['label'] as String).tr()} • $xp XP',
-                                        style: Theme.of(sheetContext)
-                                            .textTheme
-                                            .titleMedium
-                                            ?.copyWith(
-                                              fontWeight: FontWeight.w700,
-                                            ),
-                                      ),
-                                      const SizedBox(height: 2),
-                                      Text(
-                                        (goal['description'] as String).tr(),
-                                        style: Theme.of(sheetContext)
-                                            .textTheme
-                                            .bodySmall
-                                            ?.copyWith(
-                                              color: AppColorRoles.textMuted(
-                                                isDark,
-                                              ),
-                                            ),
-                                      ),
-                                    ],
-                                  ),
-                                ),
-                                if (isSelected)
-                                  AppGameIcon(
-                                    GameIcon.checkmark,
-                                    size: 24,
-                                    fallbackColor: primaryColor,
-                                  ),
-                              ],
-                            ),
-                          ),
-                        ),
-                      );
-                    }),
-                  ],
-                ),
-              ),
-            );
-          },
-        );
-      },
-    );
-  }
-
-  Widget _buildEnrolledCoursesSection(
-    BuildContext context,
-    HomeProvider provider,
-  ) {
-    // Show loading state if courses are being loaded
-    if (provider.isLoading && provider.enrolledCourses.isEmpty) {
-      return SizedBox(
-        height: 126, // Slightly increased to match card content height
-        child: ListView.builder(
-          scrollDirection: Axis.horizontal,
-          padding: const EdgeInsets.symmetric(horizontal: 16),
-          itemCount: 2,
-          itemBuilder: (context, index) {
-            return Container(
-              margin: const EdgeInsets.only(right: 16),
-              width: 240, // Reduced from 296 roughly
-              child: const CardSkeleton(isHorizontal: true),
-            );
-          },
-        ),
-      );
-    }
-
-    // Show empty state if no enrolled courses
-    if (provider.enrolledCourses.isEmpty) {
-      final isDark = Theme.of(context).brightness == Brightness.dark;
-      return Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 16),
-        child: Container(
-          padding: const EdgeInsets.all(24),
-          decoration: BoxDecoration(
-            color: isDark ? AppColors.surfaceDarkMuted : AppColors.surfaceLight,
-            borderRadius: BorderRadius.circular(12),
-            border: Border.all(
-              color: isDark
-                  ? AppColors.surfaceDarkElevated
-                  : AppColors.slate200,
-            ),
-          ),
-          child: Column(
-            children: [
-              AppGameIcon(
-                GameIcon.lessonBoard,
-                size: 48,
-                fallbackColor: isDark
-                    ? AppColors.textMuted
-                    : AppColors.textGrey,
-              ),
-              const SizedBox(height: 12),
-              Text(
-                'home.noEnrolledCoursesYet'.tr(),
-                style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                  fontWeight: FontWeight.bold,
-                  color: isDark ? AppColors.textInverted : AppColors.textDark,
-                ),
-              ),
-              const SizedBox(height: 8),
-              Text(
-                'home.enrollCoursePrompt'.tr(),
-                style: Theme.of(context).textTheme.bodySmall?.copyWith(
-                  color: isDark ? AppColors.textMuted : AppColors.textGrey,
-                ),
-                textAlign: TextAlign.center,
-              ),
-            ],
-          ),
-        ),
-      );
-    }
-
-    // Show enrolled courses
-    return _buildEnrolledCourses(context, provider);
-  }
-
-  Widget _buildEnrolledCourses(BuildContext context, HomeProvider provider) {
-    return SizedBox(
-      height: 136,
-      child: ListView.builder(
-        scrollDirection: Axis.horizontal,
-        padding: const EdgeInsets.symmetric(horizontal: 16),
-        itemCount: provider.enrolledCourses.length,
-        itemBuilder: (context, index) {
-          final course = provider.enrolledCourses[index];
-          // Staggered animation for enrolled courses
-          return AnimatedListItem(
-            index: index,
-            duration: const Duration(milliseconds: 300),
-            delayPerItem: const Duration(milliseconds: 80),
-            child: _buildEnrolledCourseCard(context, course),
-          );
-        },
-      ),
-    );
-  }
-
-  Widget _buildEnrolledCourseCard(BuildContext context, CourseEntity course) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final progress = course.userProgress ?? 0;
-    final progressColor = progress >= 80
-        ? AppColors.greenSuccessBright
-        : progress >= 50
-        ? AppColors.orange
-        : AppColorRoles.primary(isDark);
-    final colorScheme = Theme.of(context).colorScheme;
-    final surfaceBg = colorScheme.surfaceContainerHighest;
-
-    return GestureDetector(
-      onTap: () {
-        Navigator.push(
-          context,
-          MaterialPageRoute(
-            builder: (_) => CourseDetailScreen(courseId: course.id),
-          ),
-        );
-      },
-      child: Container(
-        width: 240,
-        margin: const EdgeInsets.only(right: 16),
-        decoration: BoxDecoration(
-          color: surfaceBg,
-          borderRadius: BorderRadius.circular(20),
-          border: Border.all(color: progressColor.withValues(alpha: 0.3)),
-        ),
-        child: Padding(
-          padding: const EdgeInsets.all(16),
-          child: Row(
-            children: [
-              // Course thumbnail
-              Container(
-                width: 80,
-                height: 80,
-                decoration: BoxDecoration(
-                  borderRadius: BorderRadius.circular(16),
-                  color: colorScheme.surface,
-                  image: course.thumbnailUrl != null
-                      ? DecorationImage(
-                          image: NetworkImage(course.thumbnailUrl!),
-                          fit: BoxFit.cover,
-                        )
-                      : null,
-                  border: Border.all(color: colorScheme.outlineVariant),
-                ),
-                child: course.thumbnailUrl == null
-                    ? AppGameIcon(
-                        GameIcon.lessonBoard,
-                        size: 32,
-                        fallbackColor: progressColor,
-                      )
-                    : null,
-              ),
-              const SizedBox(width: 16),
-              // Info section
-              Expanded(
-                child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  mainAxisAlignment: MainAxisAlignment.center,
-                  children: [
-                    Text(
-                      course.title,
-                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                        fontWeight: FontWeight.bold,
-                        fontSize: 14,
-                        height: 1.2,
-                      ),
-                      maxLines: 2,
-                      overflow: TextOverflow.ellipsis,
-                    ),
-                    const SizedBox(height: 4),
-                    Row(
-                      children: [
-                        Container(
-                          padding: const EdgeInsets.symmetric(
-                            horizontal: 8,
-                            vertical: 2,
-                          ),
-                          decoration: BoxDecoration(
-                            color: progressColor.withValues(alpha: 0.1),
-                            borderRadius: BorderRadius.circular(8),
-                          ),
-                          child: Text(
-                            _localizedCourseLevel(course.level),
-                            style: TextStyle(
-                              fontSize: 10,
-                              fontWeight: FontWeight.w600,
-                              color: progressColor,
-                            ),
-                          ),
+                        const Padding(
+                          padding: EdgeInsets.only(top: 12),
+                          child: LevelAndDailyGoalRow(),
                         ),
-                        const SizedBox(width: 8),
-                        Text(
-                          'profile.lessonsCount'.tr(
-                            namedArgs: {'count': '${course.totalLessons}'},
-                          ),
-                          style: Theme.of(context).textTheme.bodySmall
-                              ?.copyWith(
-                                color: AppColorRoles.textSecondary(isDark),
-                              ),
+                        const Padding(
+                          padding: EdgeInsets.fromLTRB(16, 12, 16, 0),
+                          child: DailyChallengesCard(),
                         ),
-                      ],
-                    ),
-                    const SizedBox(height: 8),
-                    // Progress bar
-                    Stack(
-                      children: [
-                        Container(
-                          height: 6,
-                          decoration: BoxDecoration(
-                            color: progressColor.withValues(alpha: 0.15),
-                            borderRadius: BorderRadius.circular(3),
-                          ),
+                        const Padding(
+                          padding: EdgeInsets.fromLTRB(16, 12, 16, 0),
+                          child: DailyReviewCard(),
                         ),
-                        FractionallySizedBox(
-                          widthFactor: progress / 100,
-                          child: Container(
-                            height: 6,
-                            decoration: BoxDecoration(
-                              gradient: LinearGradient(
-                                colors: [
-                                  progressColor,
-                                  progressColor.withValues(alpha: 0.7),
-                                ],
+                        Padding(
+                          padding: const EdgeInsets.only(top: 12),
+                          child: Column(
+                            crossAxisAlignment: CrossAxisAlignment.start,
+                            children: [
+                              SectionTitle(
+                                title: 'home.continueLearningSection'.tr(),
                               ),
-                              borderRadius: BorderRadius.circular(3),
-                            ),
-                          ),
-                        ),
-                      ],
-                    ),
-                    const SizedBox(height: 4),
-                    Row(
-                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                      children: [
-                        Expanded(
-                          child: Text(
-                            '${progress.toInt()}%',
-                            style: TextStyle(
-                              fontSize: 11,
-                              fontWeight: FontWeight.w600,
-                              color: progressColor,
-                            ),
-                            maxLines: 1,
-                            overflow: TextOverflow.ellipsis,
+                              const SizedBox(height: 8),
+                              const EnrolledCoursesSection(),
+                            ],
                           ),
                         ),
-                        Container(
-                          padding: const EdgeInsets.all(5),
-                          decoration: BoxDecoration(
-                            gradient: LinearGradient(
-                              colors: [
-                                progressColor,
-                                progressColor.withValues(alpha: 0.8),
-                              ],
-                            ),
-                            shape: BoxShape.circle,
-                            boxShadow: [
-                              BoxShadow(
-                                color: progressColor.withValues(alpha: 0.4),
-                                blurRadius: 0,
-                                offset: const Offset(0, 2),
-                              ),
+                        Padding(
+                          padding: const EdgeInsets.only(top: 12, bottom: 24),
+                          child: Column(
+                            crossAxisAlignment: CrossAxisAlignment.start,
+                            children: [
+                              SectionTitle(title: 'home.featuredCourses'.tr()),
+                              const SizedBox(height: 8),
+                              const FeaturedCoursesSection(),
                             ],
                           ),
-                          child: AppGameIcon(
-                            GameIcon.playArrow,
-                            size: 16,
-                            fallbackColor: AppColors.surfaceLight,
-                          ),
                         ),
                       ],
                     ),
-                  ],
+                  ),
                 ),
               ),
-            ],
-          ),
-        ),
-      ),
-    );
-  }
-
-  Widget _buildFeaturedCourses(BuildContext context, HomeProvider provider) {
-    // Show skeleton loading while courses are loading
-    if (provider.isLoading && provider.featuredCourses.isEmpty) {
-      return SizedBox(
-        height: 220,
-        child: ListView.builder(
-          scrollDirection: Axis.horizontal,
-          padding: const EdgeInsets.symmetric(horizontal: 16),
-          itemCount: 3,
-          itemBuilder: (context, index) {
-            return Container(
-              width: 240,
-              margin: const EdgeInsets.only(right: 16),
-              child: const CardSkeleton(isHorizontal: false),
             );
           },
         ),
-      );
-    }
-
-    if (provider.featuredCourses.isEmpty) {
-      return _buildFeaturedCoursesEmptyState(context, provider);
-    }
-
-    return SizedBox(
-      height: 220,
-      child: ListView.builder(
-        scrollDirection: Axis.horizontal,
-        padding: const EdgeInsets.symmetric(horizontal: 16),
-        itemCount: provider.featuredCourses.length,
-        itemBuilder: (context, index) {
-          final course = provider.featuredCourses[index];
-          // Staggered animation for featured courses
-          return AnimatedListItem(
-            index: index,
-            duration: const Duration(milliseconds: 400),
-            delayPerItem: const Duration(milliseconds: 100),
-            beginOffset: const Offset(0, 60),
-            child: _buildCourseCard(context, course, provider),
-          );
-        },
       ),
     );
   }
-
-  Widget _buildFeaturedCoursesEmptyState(
-    BuildContext context,
-    HomeProvider provider,
-  ) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final primary = AppColorRoles.primary(isDark);
-
-    return SizedBox(
-      height: 220,
-      child: Container(
-        margin: const EdgeInsets.symmetric(horizontal: 16),
-        padding: const EdgeInsets.all(18),
-        decoration: BoxDecoration(
-          color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
-          borderRadius: BorderRadius.circular(20),
-          border: Border.all(
-            color: primary.withValues(alpha: isDark ? 0.22 : 0.16),
-          ),
-        ),
-        child: Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            Container(
-              width: 44,
-              height: 44,
-              decoration: BoxDecoration(
-                color: primary.withValues(alpha: 0.12),
-                borderRadius: BorderRadius.circular(12),
-              ),
-              child: AppGameIcon(
-                GameIcon.book,
-                size: 24,
-                fallbackColor: primary,
-              ),
-            ),
-            const SizedBox(height: 12),
-            Text(
-              'home.noFeaturedCourses'.tr(),
-              style: Theme.of(
-                context,
-              ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w700),
-            ),
-            const SizedBox(height: 6),
-            Text(
-              'home.noFeaturedCoursesDescription'.tr(),
-              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
-                color: AppColorRoles.textMuted(isDark),
-                height: 1.35,
-              ),
-            ),
-            const Spacer(),
-            Row(
-              children: [
-                FilledButton.icon(
-                  onPressed: () => provider.loadFeaturedCourses(),
-                  icon: const Icon(Icons.refresh_rounded, size: 18),
-                  label: Text('home.reload'.tr()),
-                ),
-                const SizedBox(width: 10),
-                TextButton(
-                  onPressed: () => provider.refreshData(),
-                  child: Text('home.refreshData'.tr()),
-                ),
-              ],
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-
-  Widget _buildCourseCard(
-    BuildContext context,
-    CourseEntity course,
-    HomeProvider provider,
-  ) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final levelColor = _getLevelColor(course.level, isDark: isDark);
-
-    return GestureDetector(
-      onTap: () {
-        Navigator.push(
-          context,
-          MaterialPageRoute(
-            builder: (_) => CourseDetailScreen(
-              courseId: course.id,
-              heroTag: 'featured-course-image-${course.id}',
-              initialThumbnailUrl: course.thumbnailUrl,
-              fallbackThumbnailUrl: courseFallbackThumbnailUrl(course),
-            ),
-          ),
-        );
-      },
-      child: Container(
-        width: 240,
-        margin: const EdgeInsets.only(right: 16),
-        decoration: BoxDecoration(
-          color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
-          borderRadius: BorderRadius.circular(24),
-          border: Border.all(
-            color: isDark
-                ? Colors.white.withValues(alpha: 0.1)
-                : levelColor.withValues(alpha: 0.25),
-            width: 1,
-          ),
-        ),
-        child: Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            // Hero animation for course thumbnail
-            Hero(
-              tag: 'featured-course-image-${course.id}',
-              child: ClipRRect(
-                borderRadius: const BorderRadius.vertical(
-                  top: Radius.circular(24),
-                ),
-                child: Stack(
-                  children: [
-                    Positioned.fill(
-                      child: _buildFeaturedCourseThumbnail(
-                        context,
-                        course,
-                        levelColor,
-                      ),
-                    ),
-                    // Gradient overlay
-                    Container(
-                      height: 110,
-                      decoration: BoxDecoration(
-                        gradient: LinearGradient(
-                          begin: Alignment.topCenter,
-                          end: Alignment.bottomCenter,
-                          colors: [
-                            Colors.transparent,
-                            Colors.black.withValues(alpha: 0.6),
-                          ],
-                        ),
-                      ),
-                    ),
-                    // Level badge - top left
-                    Positioned(
-                      top: 12,
-                      left: 12,
-                      child: Container(
-                        padding: const EdgeInsets.symmetric(
-                          horizontal: 12,
-                          vertical: 6,
-                        ),
-                        decoration: BoxDecoration(
-                          gradient: LinearGradient(
-                            colors: [
-                              levelColor,
-                              levelColor.withValues(alpha: 0.85),
-                            ],
-                          ),
-                          borderRadius: BorderRadius.circular(20),
-                          boxShadow: [
-                            BoxShadow(
-                              color: levelColor.withValues(alpha: 0.5),
-                              blurRadius: 8,
-                              offset: const Offset(0, 3),
-                            ),
-                          ],
-                        ),
-                        child: Text(
-                          _localizedCourseLevel(course.level),
-                          style: TextStyle(
-                            color: AppColors.surfaceLight,
-                            fontSize: 12,
-                            fontWeight: FontWeight.bold,
-                            letterSpacing: 0.5,
-                          ),
-                        ),
-                      ),
-                    ),
-                    // XP badge - top right
-                    Positioned(
-                      top: 12,
-                      right: 12,
-                      child: Container(
-                        padding: const EdgeInsets.symmetric(
-                          horizontal: 10,
-                          vertical: 5,
-                        ),
-                        decoration: BoxDecoration(
-                          gradient: const LinearGradient(
-                            colors: [AppColors.orange, AppColors.orange],
-                          ),
-                          borderRadius: BorderRadius.circular(20),
-                          boxShadow: [
-                            BoxShadow(
-                              color: const Color(
-                                0xFFF59E0B,
-                              ).withValues(alpha: 0.4),
-                              blurRadius: 6,
-                              offset: const Offset(0, 2),
-                            ),
-                          ],
-                        ),
-                        child: Row(
-                          mainAxisSize: MainAxisSize.min,
-                          children: [
-                            AppGameIcon(
-                              GameIcon.star,
-                              size: 14,
-                              fallbackColor: AppColors.surfaceLight,
-                            ),
-                            const SizedBox(width: 4),
-                            Text(
-                              'profile.xpValue'.tr(
-                                namedArgs: {'xp': '${course.totalXp}'},
-                              ),
-                              style: TextStyle(
-                                color: AppColors.surfaceLight,
-                                fontSize: 11,
-                                fontWeight: FontWeight.bold,
-                              ),
-                            ),
-                          ],
-                        ),
-                      ),
-                    ),
-                    // Course title overlay at bottom
-                    Positioned(
-                      bottom: 12,
-                      left: 12,
-                      right: 12,
-                      child: Text(
-                        course.title,
-                        style: TextStyle(
-                          color: AppColors.surfaceLight,
-                          fontSize: 16,
-                          fontWeight: FontWeight.bold,
-                          shadows: [
-                            Shadow(
-                              color: AppColors.backgroundDark.withValues(
-                                alpha: 0.75,
-                              ),
-                              blurRadius: 4,
-                            ),
-                          ],
-                        ),
-                        maxLines: 2,
-                        overflow: TextOverflow.ellipsis,
-                      ),
-                    ),
-                  ],
-                ),
-              ),
-            ),
-            // Bottom section with info and action
-            Expanded(
-              child: Padding(
-                padding: const EdgeInsets.symmetric(
-                  horizontal: 14,
-                  vertical: 12,
-                ),
-                child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                  children: [
-                    // Info chips row
-                    Row(
-                      children: [
-                        _buildInfoChip(
-                          icon: GameIcon.lessonBoard,
-                          label: 'profile.lessonsCount'.tr(
-                            namedArgs: {'count': '${course.totalLessons}'},
-                          ),
-                          color: AppColorRoles.primary(isDark),
-                        ),
-                        const SizedBox(width: 8),
-                        _buildInfoChip(
-                          icon: GameIcon.translate,
-                          label: course.language,
-                          color: AppColors.purple,
-                        ),
-                      ],
-                    ),
-                    const SizedBox(height: 8),
-                    // Action button
-                    Container(
-                      width: double.infinity,
-                      padding: const EdgeInsets.symmetric(vertical: 10),
-                      decoration: BoxDecoration(
-                        color: levelColor,
-                        borderRadius: BorderRadius.circular(14),
-                        border: Border.all(
-                          color: levelColor.withValues(alpha: 0.6),
-                        ),
-                      ),
-                      child: Row(
-                        mainAxisAlignment: MainAxisAlignment.center,
-                        children: [
-                          AppGameIcon(
-                            GameIcon.playArrow,
-                            size: 18,
-                            fallbackColor: AppColors.surfaceLight,
-                          ),
-                          SizedBox(width: 8),
-                          Text(
-                            'home.startLearning'.tr(),
-                            style: TextStyle(
-                              color: AppColors.surfaceLight,
-                              fontSize: 14,
-                              fontWeight: FontWeight.bold,
-                              letterSpacing: 0.3,
-                            ),
-                          ),
-                        ],
-                      ),
-                    ),
-                  ],
-                ),
-              ),
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-
-  Widget _buildFeaturedCourseThumbnail(
-    BuildContext context,
-    CourseEntity course,
-    Color levelColor, [
-    int index = 0,
-  ]) {
-    final candidates = buildCourseCardThumbnailCandidates(course);
-    if (index >= candidates.length) {
-      return _buildFeaturedCourseThumbnailPlaceholder(context, levelColor);
-    }
-
-    return CachedNetworkImage(
-      imageUrl: candidates[index],
-      fit: BoxFit.cover,
-      placeholder: (_, __) =>
-          Container(color: levelColor.withValues(alpha: 0.1)),
-      errorWidget: (_, __, ___) =>
-          _buildFeaturedCourseThumbnail(context, course, levelColor, index + 1),
-    );
-  }
-
-  Widget _buildFeaturedCourseThumbnailPlaceholder(
-    BuildContext context,
-    Color levelColor,
-  ) {
-    return Container(
-      color: levelColor.withValues(alpha: 0.1),
-      alignment: Alignment.center,
-      child: Container(
-        padding: const EdgeInsets.all(20),
-        decoration: BoxDecoration(
-          color: Theme.of(context).colorScheme.surface.withValues(alpha: 0.15),
-          shape: BoxShape.circle,
-          border: Border.all(
-            color: Theme.of(context).colorScheme.surface.withValues(alpha: 0.3),
-            width: 2,
-          ),
-        ),
-        child: const AppGameIcon(
-          GameIcon.lessonBoard,
-          size: 40,
-          fallbackColor: AppColors.surfaceLight,
-        ),
-      ),
-    );
-  }
-
-  Widget _buildInfoChip({
-    required GameIcon icon,
-    required String label,
-    required Color color,
-  }) {
-    return Container(
-      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
-      decoration: BoxDecoration(
-        color: color.withValues(alpha: 0.1),
-        borderRadius: BorderRadius.circular(10),
-        border: Border.all(color: color.withValues(alpha: 0.2), width: 1.5),
-      ),
-      child: Row(
-        mainAxisSize: MainAxisSize.min,
-        children: [
-          AppGameIcon(icon, size: 14, fallbackColor: color),
-          const SizedBox(width: 5),
-          Text(
-            label,
-            style: TextStyle(
-              fontSize: 11,
-              fontWeight: FontWeight.w600,
-              color: color,
-            ),
-          ),
-        ],
-      ),
-    );
-  }
-
-  Color _getLevelColor(String level, {bool isDark = false}) {
-    switch (level.toLowerCase()) {
-      case 'beginner':
-        return AppColors.greenSuccessBright;
-      case 'elementary':
-        return AppColors.greenSuccessSoft;
-      case 'intermediate':
-        return AppColors.orange;
-      case 'upper-intermediate':
-        return AppColors.orange;
-      case 'advanced':
-        return AppColors.dangerGradient[0];
-      default:
-        return AppColorRoles.primary(isDark);
-    }
-  }
-
-  String _localizedCourseLevel(String level) {
-    switch (level.toLowerCase()) {
-      case 'beginner':
-        return 'course.difficulty.beginner'.tr();
-      case 'elementary':
-        return 'course.difficulty.elementary'.tr();
-      case 'intermediate':
-        return 'course.difficulty.intermediate'.tr();
-      case 'upper-intermediate':
-        return 'course.difficulty.upperIntermediate'.tr();
-      case 'advanced':
-        return 'course.difficulty.advanced'.tr();
-      default:
-        return level;
-    }
-  }
-
-  /// Quick Actions - Horizontal scrollable section with circular buttons
-  Widget _buildQuickActionsHorizontal(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final accent = AppColorRoles.primary(isDark);
-    // Keep all dark-mode quick actions in a consistent neon range.
-    const neonDarkActionColors = <Color>[
-      Color(0xFFFF3131), // YouTube
-      Color(0xFFFC1AD3), // News
-      Color(0xFFFFA319), // Games
-      Color(0xFF35FF0D), // Podcast
-      Color(0xFF8B5CFF), // Books (neon purple)
-      Color(0xFFFF369E), // Vocabulary
-    ];
-
-    final quickActions = [
-      {
-        'icon': Icons.smart_display,
-        'label': 'home.youtube',
-        'color': isDark ? neonDarkActionColors[0] : AppColors.dangerGradient[0],
-        'bgColor':
-            (isDark ? neonDarkActionColors[0] : AppColors.dangerGradient[0])
-                .withValues(alpha: isDark ? 0.16 : 0.1),
-        'route': '/youtube',
-      },
-      {
-        'icon': GameIcon.newspaper,
-        'label': 'home.news',
-        'color': isDark ? neonDarkActionColors[1] : AppColors.teal,
-        'bgColor': (isDark ? neonDarkActionColors[1] : AppColors.teal)
-            .withValues(alpha: isDark ? 0.16 : 0.1),
-        'route': '/news',
-      },
-      {
-        'icon': GameIcon.gameController,
-        'label': 'home.games',
-        'color': isDark ? neonDarkActionColors[2] : AppColors.purple,
-        'bgColor': (isDark ? neonDarkActionColors[2] : AppColors.purple)
-            .withValues(alpha: isDark ? 0.16 : 0.1),
-        'route': '/games',
-      },
-      {
-        'icon': GameIcon.headphones,
-        'label': 'home.podcast',
-        'color': isDark ? neonDarkActionColors[3] : accent,
-        'bgColor': (isDark ? neonDarkActionColors[3] : accent).withValues(
-          alpha: isDark ? 0.16 : 0.12,
-        ),
-        'route': '/podcast',
-      },
-      {
-        'icon': GameIcon.book,
-        'label': 'home.books',
-        'color': isDark ? neonDarkActionColors[4] : AppColors.purpleLight,
-        'bgColor': (isDark ? neonDarkActionColors[4] : AppColors.purple)
-            .withValues(alpha: isDark ? 0.16 : 0.1),
-        'route': '/books',
-      },
-      {
-        'icon': GameIcon.vocabulary,
-        'label': 'home.vocabulary',
-        'color': isDark ? neonDarkActionColors[5] : AppColors.orange,
-        'bgColor': (isDark ? neonDarkActionColors[5] : AppColors.warning)
-            .withValues(alpha: isDark ? 0.16 : 0.1),
-        'route': '/vocab',
-      },
-    ];
-
-    const double chipHeight = 50.0;
-    
-    return SizedBox(
-      height: chipHeight,
-      child: ListView.builder(
-        scrollDirection: Axis.horizontal,
-        physics: const BouncingScrollPhysics(),
-        padding: const EdgeInsets.symmetric(horizontal: 16),
-        itemCount: quickActions.length,
-        itemBuilder: (context, index) {
-          final action = quickActions[index];
-          return Padding(
-            padding: const EdgeInsets.only(right: 10),
-            child: _buildQuickActionChip(
-              context,
-              icon: action['icon']!,
-              label: (action['label'] as String).tr(),
-              color: action['color'] as Color,
-              bgColor: action['bgColor'] as Color,
-              onTap: () {
-                final route = action['route'] as String;
-                if (route == '/vocab') {
-                  Navigator.push(
-                    context,
-                    MaterialPageRoute(
-                      builder: (_) => const VocabLibraryPage(),
-                    ),
-                  );
-                } else {
-                  Navigator.pushNamed(context, route);
-                }
-              },
-            ),
-          );
-        },
-      ),
-    );
-  }
-
-  Widget _buildQuickActionChip(
-    BuildContext context, {
-    required Object icon,
-    required String label,
-    required Color color,
-    required Color bgColor,
-    required VoidCallback onTap,
-  }) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    
-    return GestureDetector(
-      onTap: onTap,
-      child: Container(
-        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 8),
-        decoration: BoxDecoration(
-          color: bgColor,
-          borderRadius: BorderRadius.circular(24),
-          border: Border.all(
-            color: color.withValues(alpha: isDark ? 0.5 : 0.35),
-            width: 1.5,
-          ),
-        ),
-        child: Row(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            icon is GameIcon
-                ? AppGameIcon(
-                    icon,
-                    size: 20,
-                    fallbackColor: color,
-                  )
-                : Icon(
-                    icon as IconData,
-                    color: color,
-                    size: 20,
-                  ),
-            const SizedBox(width: 8),
-            Text(
-              label,
-              style: TextStyle(
-                fontSize: 12,
-                fontWeight: FontWeight.bold,
-                color: color,
-              ),
-              maxLines: 1,
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-
-  // ignore: unused_element
-  Widget _buildQuickStats(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final stats = [
-      _QuickStat(
-        icon: Icons.article_rounded,
-        label: 'home.articles'.tr(),
-        value: '—',
-        color: AppColorRoles.primary(isDark),
-      ),
-      _QuickStat(
-        icon: Icons.sports_esports_rounded,
-        label: 'home.games'.tr(),
-        value: '—',
-        color: AppColors.purple,
-      ),
-      _QuickStat(
-        icon: Icons.headphones_rounded,
-        label: 'home.listened'.tr(),
-        value: '—',
-        color: AppColorRoles.primary(isDark),
-      ),
-      _QuickStat(
-        icon: Icons.menu_book_rounded,
-        label: 'home.reading'.tr(),
-        value: '—',
-        color: AppColors.greenSuccessBright,
-      ),
-    ];
-    return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: 16),
-      child: Row(
-        children: stats
-            .expand(
-              (s) => [
-                Expanded(
-                  child: Container(
-                    padding: const EdgeInsets.symmetric(vertical: 12),
-                    decoration: BoxDecoration(
-                      color: isDark
-                          ? AppColors.surfaceDarkElevated
-                          : Colors.white,
-                      borderRadius: BorderRadius.circular(12),
-                      border: Border.all(color: s.color.withValues(alpha: 0.2)),
-                    ),
-                    child: Column(
-                      children: [
-                        Icon(s.icon, color: s.color, size: 22),
-                        const SizedBox(height: 4),
-                        Text(
-                          s.value,
-                          style: TextStyle(
-                            fontWeight: FontWeight.w700,
-                            fontSize: 16,
-                            color: isDark ? Colors.white : AppColors.textDark,
-                          ),
-                        ),
-                        Text(
-                          s.label,
-                          style: TextStyle(
-                            fontSize: 10,
-                            color: isDark ? Colors.white54 : AppColors.textGrey,
-                          ),
-                        ),
-                      ],
-                    ),
-                  ),
-                ),
-                const SizedBox(width: 8),
-              ],
-            )
-            .take(stats.length * 2 - 1)
-            .toList(),
-      ),
-    );
-  }
-
-  // ignore: unused_element
-  Widget _buildContinueSection(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    return Consumer<BookProvider>(
-      builder: (context, bookProvider, _) {
-        final currentBook = bookProvider.currentBook;
-        final currentProgress = bookProvider.currentProgress;
-
-        final items = <_ContinueItem>[
-          _ContinueItem(
-            icon: Icons.smart_display_rounded,
-            title: 'home.youtube'.tr(),
-            subtitle: 'home.continueWatching'.tr(),
-            color: AppColors.dangerGradient[0],
-            route: '/youtube',
-          ),
-          _ContinueItem(
-            icon: Icons.article_rounded,
-            title: 'home.news'.tr(),
-            subtitle: 'home.continueReading'.tr(),
-            color: AppColorRoles.primary(isDark),
-            route: '/news',
-          ),
-          _ContinueItem(
-            icon: Icons.sports_esports_rounded,
-            title: 'home.games'.tr(),
-            subtitle: 'home.earnMoreXp'.tr(),
-            color: AppColors.purple,
-            route: '/games',
-          ),
-          _ContinueItem(
-            icon: Icons.podcasts_rounded,
-            title: 'home.podcast'.tr(),
-            subtitle: 'home.continueListening'.tr(),
-            color: AppColorRoles.primary(isDark),
-            route: '/podcast',
-          ),
-          if (currentBook != null)
-            _ContinueItem(
-              icon: Icons.menu_book_rounded,
-              title: currentBook.title.length > 18
-                  ? '${currentBook.title.substring(0, 18)}…'
-                  : currentBook.title,
-              subtitle: currentProgress != null
-                  ? 'home.percentRead'.tr(
-                      namedArgs: {
-                        'percent':
-                            '${(currentProgress.readingProgress * 100).toInt()}',
-                      },
-                    )
-                  : 'home.continueReading'.tr(),
-              color: AppColors.greenSuccessBright,
-              route: '/books',
-            )
-          else
-            _ContinueItem(
-              icon: Icons.menu_book_rounded,
-              title: 'home.books'.tr(),
-              subtitle: 'home.startReading'.tr(),
-              color: AppColors.greenSuccessBright,
-              route: '/books',
-            ),
-        ];
-
-        return SizedBox(
-          height: 116,
-          child: ListView.separated(
-            scrollDirection: Axis.horizontal,
-            padding: const EdgeInsets.symmetric(horizontal: 16),
-            itemCount: items.length,
-            separatorBuilder: (_, __) => const SizedBox(width: 12),
-            itemBuilder: (context, i) {
-              final item = items[i];
-              return GestureDetector(
-                onTap: () => Navigator.pushNamed(context, item.route),
-                child: Container(
-                  width: 130,
-                  padding: const EdgeInsets.all(14),
-                  decoration: BoxDecoration(
-                    color: isDark
-                        ? AppColors.surfaceDarkElevated
-                        : Colors.white,
-                    borderRadius: BorderRadius.circular(16),
-                    border: Border.all(
-                      color: item.color.withValues(alpha: 0.25),
-                    ),
-                  ),
-                  child: Column(
-                    crossAxisAlignment: CrossAxisAlignment.start,
-                    mainAxisAlignment: MainAxisAlignment.center,
-                    children: [
-                      Container(
-                        width: 36,
-                        height: 36,
-                        decoration: BoxDecoration(
-                          color: item.color.withValues(alpha: 0.12),
-                          borderRadius: BorderRadius.circular(8),
-                        ),
-                        child: Icon(item.icon, color: item.color, size: 20),
-                      ),
-                      const SizedBox(height: 8),
-                      Text(
-                        item.title,
-                        maxLines: 1,
-                        overflow: TextOverflow.ellipsis,
-                        style: TextStyle(
-                          fontWeight: FontWeight.w700,
-                          fontSize: 13,
-                          color: isDark ? Colors.white : AppColors.textDark,
-                        ),
-                      ),
-                      Text(
-                        item.subtitle,
-                        maxLines: 1,
-                        overflow: TextOverflow.ellipsis,
-                        style: TextStyle(
-                          fontSize: 11,
-                          color: isDark ? Colors.white54 : AppColors.textGrey,
-                        ),
-                      ),
-                    ],
-                  ),
-                ),
-              );
-            },
-          ),
-        );
-      },
-    );
-  }
-
-  Widget _buildSectionTitle(BuildContext context, String title) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: 16.0),
-      child: Text(
-        title,
-        style: Theme.of(context).textTheme.titleLarge?.copyWith(
-          fontWeight: FontWeight.bold,
-          fontSize: 18,
-          color: AppColorRoles.textPrimary(isDark),
-        ),
-      ),
-    );
-  }
-
-  /// Build skeleton loading state for home page
-  Widget _buildSkeletonLoading() {
-    return SingleChildScrollView(
-      padding: const EdgeInsets.only(bottom: 24.0),
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          // Header skeleton
-          ShimmerContainer(
-            child: Padding(
-              padding: const EdgeInsets.all(16.0),
-              child: Row(
-                children: [
-                  const SkeletonCircle(size: 48),
-                  const SizedBox(width: 12),
-                  Column(
-                    crossAxisAlignment: CrossAxisAlignment.start,
-                    children: [
-                      SkeletonText(width: 150, height: 14),
-                      SizedBox(height: 6),
-                      SkeletonText(width: 100, height: 12),
-                      SizedBox(height: 6),
-                      SkeletonText(width: 120, height: 18),
-                    ],
-                  ),
-                  const Spacer(),
-                  const SkeletonCircle(size: 40),
-                ],
-              ),
-            ),
-          ),
-          const SizedBox(height: 16),
-          // Streak card skeleton
-          const SkeletonProgressStats(),
-          const SizedBox(height: 24),
-          // Daily goal skeleton
-          ShimmerContainer(
-            child: Container(
-              margin: EdgeInsets.symmetric(horizontal: 16),
-              height: 120,
-              decoration: BoxDecoration(
-                color: Theme.of(context).colorScheme.surface,
-                borderRadius: BorderRadius.circular(16),
-              ),
-            ),
-          ),
-          const SizedBox(height: 24),
-          // Section title skeleton
-          Padding(
-            padding: const EdgeInsets.symmetric(horizontal: 16.0),
-            child: ShimmerContainer(
-              child: SkeletonText(width: 150, height: 20),
-            ),
-          ),
-          const SizedBox(height: 12),
-          // Courses skeleton
-          const SkeletonHomeSection(),
-          const SizedBox(height: 24),
-          // Another section
-          const SkeletonHomeSection(),
-        ],
-      ),
-    );
-  }
-}
-
-class _QuickStat {
-  final IconData icon;
-  final String label;
-  final String value;
-  final Color color;
-
-  const _QuickStat({
-    required this.icon,
-    required this.label,
-    required this.value,
-    required this.color,
-  });
-}
-
-class _ContinueItem {
-  final IconData icon;
-  final String title;
-  final String subtitle;
-  final Color color;
-  final String route;
-
-  const _ContinueItem({
-    required this.icon,
-    required this.title,
-    required this.subtitle,
-    required this.color,
-    required this.route,
-  });
 }
diff --git a/flutter-app/lib/features/home/presentation/pages/main_screen.dart b/flutter-app/lib/features/home/presentation/pages/main_screen.dart
index 81b51370..91d89f32 100644
--- a/flutter-app/lib/features/home/presentation/pages/main_screen.dart
+++ b/flutter-app/lib/features/home/presentation/pages/main_screen.dart
@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:easy_localization/easy_localization.dart';
 import 'package:http/http.dart' as http;
-import 'package:phosphor_flutter/phosphor_flutter.dart';
 import 'package:provider/provider.dart';
 import '../../../chat/presentation/providers/story_provider.dart';
 import '../../../auth/presentation/providers/auth_provider.dart';
@@ -127,97 +126,157 @@ class _MainScreenState extends State<MainScreen> {
 
   @override
   Widget build(BuildContext context) {
+    final width = MediaQuery.sizeOf(context).width;
+    final useRail = width >= 840;
+
     return Scaffold(
       resizeToAvoidBottomInset: false,
-      body: IndexedStack(
-        index: _currentIndex,
-        children: List.generate(_pageCount, (i) {
-          // Use a lightweight placeholder until the tab is first visited.
-          return _pageCache.containsKey(i)
-              ? _pageCache[i]!
-              : const SizedBox.shrink();
-        }),
-      ),
-      bottomNavigationBar: Builder(
-        builder: (context) {
-          final isDark = Theme.of(context).brightness == Brightness.dark;
-          return Container(
-            decoration: BoxDecoration(
-              color: isDark ? AppColors.surfaceDark : Colors.white,
-              borderRadius: const BorderRadius.only(
-                topLeft: Radius.circular(24),
-                topRight: Radius.circular(24),
-              ),
-              boxShadow: [
-                BoxShadow(
-                  color: isDark
-                      ? Colors.black.withValues(alpha: 0.4)
-                      : Colors.black.withValues(alpha: 0.08),
-                  blurRadius: 20,
-                  spreadRadius: 0,
-                  offset: const Offset(0, -4),
-                ),
+      body: useRail
+          ? Row(
+              children: [
+                _buildNavigationRail(context, width),
+                Expanded(child: _buildPageStack()),
               ],
+            )
+          : _buildPageStack(),
+      bottomNavigationBar: useRail ? null : _buildBottomNavigationBar(context),
+    );
+  }
+
+  Widget _buildPageStack() {
+    return IndexedStack(
+      index: _currentIndex,
+      children: List.generate(_pageCount, (i) {
+        // Use a lightweight placeholder until the tab is first visited.
+        return _pageCache.containsKey(i)
+            ? _pageCache[i]!
+            : const SizedBox.shrink();
+      }),
+    );
+  }
+
+  void _selectTab(int index) {
+    if (index == 2 && !_lexiWarmedUp) {
+      _lexiWarmedUp = true;
+      _warmupAiModels();
+    }
+    setState(() {
+      _getPage(index); // build page lazily on first visit
+      _currentIndex = index;
+    });
+  }
+
+  Widget _buildNavigationRail(BuildContext context, double width) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final extended = width >= 1100;
+
+    return DecoratedBox(
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDark : Colors.white,
+        border: Border(
+          right: BorderSide(
+            color: isDark ? AppColors.surfaceDarkMuted : AppColors.slate200,
+          ),
+        ),
+      ),
+      child: SafeArea(
+        child: NavigationRail(
+          selectedIndex: _currentIndex,
+          extended: extended,
+          minExtendedWidth: 190,
+          labelType: extended
+              ? NavigationRailLabelType.none
+              : NavigationRailLabelType.selected,
+          onDestinationSelected: _selectTab,
+          destinations: [
+            NavigationRailDestination(
+              icon: const Icon(Icons.explore_outlined),
+              selectedIcon: const Icon(Icons.explore),
+              label: Text('home.navDiscovery'.tr()),
             ),
-            child: ClipRRect(
-              borderRadius: const BorderRadius.only(
-                topLeft: Radius.circular(24),
-                topRight: Radius.circular(24),
-              ),
-              child: BottomNavigationBar(
-                currentIndex: _currentIndex,
-                type: BottomNavigationBarType.fixed,
-                onTap: (index) {
-                  if (index == 2 && !_lexiWarmedUp) {
-                    _lexiWarmedUp = true;
-                    _warmupAiModels();
-                  }
-                  setState(() {
-                    _getPage(index); // build page lazily on first visit
-                    _currentIndex = index;
-                  });
-                },
-                items: [
-                  BottomNavigationBarItem(
-                    icon: Icon(PhosphorIcons.compass()),
-                    activeIcon: Icon(
-                      PhosphorIcons.compass(PhosphorIconsStyle.fill),
-                    ),
-                    label: 'home.navDiscovery'.tr(),
-                  ),
-                  BottomNavigationBarItem(
-                    icon: Icon(PhosphorIcons.bookOpen()),
-                    activeIcon: Icon(
-                      PhosphorIcons.bookOpen(PhosphorIconsStyle.fill),
-                    ),
-                    label: 'home.navLearning'.tr(),
-                  ),
-                  BottomNavigationBarItem(
-                    icon: Icon(PhosphorIcons.bird()),
-                    activeIcon: Icon(
-                      PhosphorIcons.bird(PhosphorIconsStyle.fill),
-                    ),
-                    label: 'home.navLexi'.tr(),
-                  ),
-                  BottomNavigationBarItem(
-                    icon: Icon(PhosphorIcons.chatCircleText()),
-                    activeIcon: Icon(
-                      PhosphorIcons.chatCircleText(PhosphorIconsStyle.fill),
-                    ),
-                    label: 'home.navTopic'.tr(),
-                  ),
-                  BottomNavigationBarItem(
-                    icon: Icon(PhosphorIcons.userCircle()),
-                    activeIcon: Icon(
-                      PhosphorIcons.userCircle(PhosphorIconsStyle.fill),
-                    ),
-                    label: 'home.navAccount'.tr(),
-                  ),
-                ],
-              ),
+            NavigationRailDestination(
+              icon: const Icon(Icons.menu_book_outlined),
+              selectedIcon: const Icon(Icons.menu_book),
+              label: Text('home.navLearning'.tr()),
+            ),
+            NavigationRailDestination(
+              icon: const Icon(Icons.smart_toy_outlined),
+              selectedIcon: const Icon(Icons.smart_toy),
+              label: Text('home.navLexi'.tr()),
+            ),
+            NavigationRailDestination(
+              icon: const Icon(Icons.chat_bubble_outline),
+              selectedIcon: const Icon(Icons.chat_bubble),
+              label: Text('home.navTopic'.tr()),
+            ),
+            NavigationRailDestination(
+              icon: const Icon(Icons.account_circle_outlined),
+              selectedIcon: const Icon(Icons.account_circle),
+              label: Text('home.navAccount'.tr()),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  Widget _buildBottomNavigationBar(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    return Container(
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDark : Colors.white,
+        borderRadius: const BorderRadius.only(
+          topLeft: Radius.circular(24),
+          topRight: Radius.circular(24),
+        ),
+        boxShadow: [
+          BoxShadow(
+            color: isDark
+                ? Colors.black.withValues(alpha: 0.4)
+                : Colors.black.withValues(alpha: 0.08),
+            blurRadius: 20,
+            spreadRadius: 0,
+            offset: const Offset(0, -4),
+          ),
+        ],
+      ),
+      child: ClipRRect(
+        borderRadius: const BorderRadius.only(
+          topLeft: Radius.circular(24),
+          topRight: Radius.circular(24),
+        ),
+        child: BottomNavigationBar(
+          currentIndex: _currentIndex,
+          type: BottomNavigationBarType.fixed,
+          onTap: _selectTab,
+          items: [
+            BottomNavigationBarItem(
+              icon: const Icon(Icons.explore_outlined),
+              activeIcon: const Icon(Icons.explore),
+              label: 'home.navDiscovery'.tr(),
+            ),
+            BottomNavigationBarItem(
+              icon: const Icon(Icons.menu_book_outlined),
+              activeIcon: const Icon(Icons.menu_book),
+              label: 'home.navLearning'.tr(),
             ),
-          );
-        },
+            BottomNavigationBarItem(
+              icon: const Icon(Icons.smart_toy_outlined),
+              activeIcon: const Icon(Icons.smart_toy),
+              label: 'home.navLexi'.tr(),
+            ),
+            BottomNavigationBarItem(
+              icon: const Icon(Icons.chat_bubble_outline),
+              activeIcon: const Icon(Icons.chat_bubble),
+              label: 'home.navTopic'.tr(),
+            ),
+            BottomNavigationBarItem(
+              icon: const Icon(Icons.account_circle_outlined),
+              activeIcon: const Icon(Icons.account_circle),
+              label: 'home.navAccount'.tr(),
+            ),
+          ],
+        ),
       ),
     );
   }
diff --git a/flutter-app/lib/features/home/presentation/pages/today_plan_page.dart b/flutter-app/lib/features/home/presentation/pages/today_plan_page.dart
new file mode 100644
index 00000000..963f0cf2
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/pages/today_plan_page.dart
@@ -0,0 +1,234 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_models.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_navigation.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_section.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/proficiency_provider.dart';
+import 'package:lexilingo_app/features/progress/presentation/providers/daily_challenges_provider.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/repositories/vocabulary_repository.dart';
+import 'package:lexilingo_app/features/vocabulary/vocabulary_di.dart'
+    as vocab_di;
+
+class TodayPlanPage extends StatefulWidget {
+  const TodayPlanPage({super.key});
+
+  @override
+  State<TodayPlanPage> createState() => _TodayPlanPageState();
+}
+
+class _TodayPlanPageState extends State<TodayPlanPage> {
+  int? _dueVocabularyCount;
+  bool _isLoadingVocabulary = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _loadData();
+  }
+
+  Future<void> _loadData() async {
+    await Future.wait([
+      _loadVocabularyStats(),
+      context.read<DailyChallengesProvider>().refresh(),
+      context.read<ProficiencyProvider>().loadProfile(),
+    ]);
+  }
+
+  Future<void> _loadVocabularyStats() async {
+    if (mounted) {
+      setState(() => _isLoadingVocabulary = true);
+    }
+
+    final result = await vocab_di
+        .getIt<VocabularyRepository>()
+        .getVocabularyStats();
+
+    if (!mounted) return;
+
+    setState(() {
+      _dueVocabularyCount = result.fold(
+        (_) => null,
+        (stats) => stats['due_for_review'] as int? ?? 0,
+      );
+      _isLoadingVocabulary = false;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('home.todayPlan.title'.tr()),
+        leading: IconButton(
+          icon: const Icon(Icons.arrow_back_ios_new_rounded),
+          onPressed: () => Navigator.of(context).pop(),
+        ),
+      ),
+      body:
+          Consumer3<HomeProvider, DailyChallengesProvider, ProficiencyProvider>(
+            builder: (context, home, challenges, proficiency, _) {
+              final snapshot = buildTodayPlanSnapshot(
+                enrolledCourses: home.enrolledCourses,
+                challenges: challenges.challenges,
+                weakestSkills: proficiency.weakestSkills,
+                dueVocabularyCount: _isLoadingVocabulary
+                    ? null
+                    : _dueVocabularyCount,
+              );
+              final nextTask = snapshot.nextTask;
+
+              return RefreshIndicator(
+                onRefresh: () async {
+                  await Future.wait([home.refreshData(), _loadData()]);
+                },
+                child: ListView(
+                  physics: const AlwaysScrollableScrollPhysics(),
+                  padding: const EdgeInsets.fromLTRB(16, 8, 16, 28),
+                  children: [
+                    _TodayPlanHero(snapshot: snapshot, color: accent),
+                    const SizedBox(height: 16),
+                    if (nextTask != null)
+                      SizedBox(
+                        width: double.infinity,
+                        height: 52,
+                        child: ElevatedButton.icon(
+                          onPressed: () => openTodayPlanTask(context, nextTask),
+                          icon: Icon(nextTask.icon),
+                          label: Text('home.todayPlan.startNext'.tr()),
+                          style: ElevatedButton.styleFrom(
+                            backgroundColor: accent,
+                            foregroundColor: Theme.of(
+                              context,
+                            ).colorScheme.surface,
+                            shape: RoundedRectangleBorder(
+                              borderRadius: BorderRadius.circular(14),
+                            ),
+                          ),
+                        ),
+                      ),
+                    const SizedBox(height: 18),
+                    Text(
+                      'home.todayPlan.sequenceTitle'.tr(),
+                      style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                        fontWeight: FontWeight.w800,
+                      ),
+                    ),
+                    const SizedBox(height: 10),
+                    ...snapshot.tasks.map(
+                      (task) => Padding(
+                        padding: const EdgeInsets.only(bottom: 12),
+                        child: TodayPlanTaskTile(
+                          task: task,
+                          onTap: () => openTodayPlanTask(context, task),
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              );
+            },
+          ),
+    );
+  }
+}
+
+class _TodayPlanHero extends StatelessWidget {
+  const _TodayPlanHero({required this.snapshot, required this.color});
+
+  final TodayPlanSnapshot snapshot;
+  final Color color;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final colorScheme = Theme.of(context).colorScheme;
+
+    return Container(
+      padding: const EdgeInsets.all(18),
+      decoration: BoxDecoration(
+        gradient: LinearGradient(
+          colors: [color, color.withValues(alpha: 0.74)],
+          begin: Alignment.topLeft,
+          end: Alignment.bottomRight,
+        ),
+        borderRadius: BorderRadius.circular(22),
+        boxShadow: [
+          BoxShadow(
+            color: color.withValues(alpha: isDark ? 0.24 : 0.20),
+            blurRadius: 18,
+            offset: const Offset(0, 10),
+          ),
+        ],
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              Container(
+                width: 48,
+                height: 48,
+                decoration: BoxDecoration(
+                  color: colorScheme.surface.withValues(alpha: 0.18),
+                  borderRadius: BorderRadius.circular(16),
+                ),
+                child: Icon(
+                  Icons.route_rounded,
+                  color: colorScheme.surface,
+                  size: 28,
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Text(
+                  'home.todayPlan.heroTitle'.tr(),
+                  style: Theme.of(context).textTheme.headlineSmall?.copyWith(
+                    color: colorScheme.surface,
+                    fontWeight: FontWeight.w900,
+                  ),
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 18),
+          Text(
+            'home.todayPlan.heroSubtitle'.tr(),
+            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+              color: colorScheme.surface.withValues(alpha: 0.88),
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+          const SizedBox(height: 18),
+          ClipRRect(
+            borderRadius: BorderRadius.circular(999),
+            child: LinearProgressIndicator(
+              minHeight: 9,
+              value: snapshot.progress,
+              backgroundColor: colorScheme.surface.withValues(alpha: 0.20),
+              valueColor: AlwaysStoppedAnimation<Color>(colorScheme.surface),
+            ),
+          ),
+          const SizedBox(height: 10),
+          Text(
+            'home.todayPlan.completedSummary'.tr(
+              namedArgs: {
+                'completed': '${snapshot.completedCount}',
+                'total': '${snapshot.totalCount}',
+              },
+            ),
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: colorScheme.surface.withValues(alpha: 0.86),
+              fontWeight: FontWeight.w700,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/course_level_helpers.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/course_level_helpers.dart
new file mode 100644
index 00000000..3c6ca435
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/course_level_helpers.dart
@@ -0,0 +1,37 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+Color getLevelColor(String level, {bool isDark = false}) {
+  switch (level.toLowerCase()) {
+    case 'beginner':
+      return AppColors.greenSuccessBright;
+    case 'elementary':
+      return AppColors.greenSuccessSoft;
+    case 'intermediate':
+      return AppColors.orange;
+    case 'upper-intermediate':
+      return AppColors.orange;
+    case 'advanced':
+      return AppColors.dangerGradient[0];
+    default:
+      return AppColorRoles.primary(isDark);
+  }
+}
+
+String localizedCourseLevel(String level) {
+  switch (level.toLowerCase()) {
+    case 'beginner':
+      return 'course.difficulty.beginner'.tr();
+    case 'elementary':
+      return 'course.difficulty.elementary'.tr();
+    case 'intermediate':
+      return 'course.difficulty.intermediate'.tr();
+    case 'upper-intermediate':
+      return 'course.difficulty.upperIntermediate'.tr();
+    case 'advanced':
+      return 'course.difficulty.advanced'.tr();
+    default:
+      return level;
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/enrolled_courses_section.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/enrolled_courses_section.dart
new file mode 100644
index 00000000..e9bd2204
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/enrolled_courses_section.dart
@@ -0,0 +1,291 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/widgets.dart';
+import 'package:lexilingo_app/features/course/domain/entities/course_entity.dart';
+import 'package:lexilingo_app/features/course/presentation/screens/course_detail_screen.dart';
+import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/course_level_helpers.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_ui_components.dart';
+
+class EnrolledCoursesSection extends StatelessWidget {
+  const EnrolledCoursesSection({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final provider = context.watch<HomeProvider>();
+
+    // Show loading state if courses are being loaded
+    if (provider.isLoading && provider.enrolledCourses.isEmpty) {
+      return SizedBox(
+        height: 126, // Slightly increased to match card content height
+        child: ListView.builder(
+          scrollDirection: Axis.horizontal,
+          padding: const EdgeInsets.symmetric(horizontal: 16),
+          itemCount: 2,
+          itemBuilder: (context, index) {
+            return Container(
+              margin: const EdgeInsets.only(right: 16),
+              width: 240, // Reduced from 296 roughly
+              child: const CardSkeleton(isHorizontal: true),
+            );
+          },
+        ),
+      );
+    }
+
+    // Show empty state if no enrolled courses
+    if (provider.enrolledCourses.isEmpty) {
+      final isDark = Theme.of(context).brightness == Brightness.dark;
+      return Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 16),
+        child: Container(
+          padding: const EdgeInsets.all(24),
+          decoration: BoxDecoration(
+            color: isDark ? AppColors.surfaceDarkMuted : AppColors.surfaceLight,
+            borderRadius: BorderRadius.circular(12),
+            border: Border.all(
+              color: isDark
+                  ? AppColors.surfaceDarkElevated
+                  : AppColors.slate200,
+            ),
+          ),
+          child: Column(
+            children: [
+              Icon(
+                Icons.school_outlined,
+                size: 48,
+                color: isDark ? AppColors.textMuted : AppColors.textGrey,
+              ),
+              const SizedBox(height: 12),
+              Text(
+                'home.noEnrolledCoursesYet'.tr(),
+                style: Theme.of(context).textTheme.titleMedium?.copyWith(
+                  fontWeight: FontWeight.bold,
+                  color: isDark ? AppColors.textInverted : AppColors.textDark,
+                ),
+              ),
+              const SizedBox(height: 8),
+              Text(
+                'home.enrollCoursePrompt'.tr(),
+                style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                  color: isDark ? AppColors.textMuted : AppColors.textGrey,
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ],
+          ),
+        ),
+      );
+    }
+
+    // Show enrolled courses
+    return SizedBox(
+      height: 136,
+      child: ListView.builder(
+        scrollDirection: Axis.horizontal,
+        padding: const EdgeInsets.symmetric(horizontal: 16),
+        itemCount: provider.enrolledCourses.length,
+        itemBuilder: (context, index) {
+          final course = provider.enrolledCourses[index];
+          // Staggered animation for enrolled courses
+          return AnimatedListItem(
+            index: index,
+            duration: const Duration(milliseconds: 300),
+            delayPerItem: const Duration(milliseconds: 80),
+            child: _EnrolledCourseCard(course: course),
+          );
+        },
+      ),
+    );
+  }
+}
+
+class _EnrolledCourseCard extends StatelessWidget {
+  final CourseEntity course;
+
+  const _EnrolledCourseCard({required this.course});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final progress = course.userProgress ?? 0;
+    final progressColor = progress >= 80
+        ? AppColors.greenSuccessBright
+        : progress >= 50
+        ? AppColors.orange
+        : AppColorRoles.primary(isDark);
+    final colorScheme = Theme.of(context).colorScheme;
+    final surfaceBg = colorScheme.surfaceContainerHighest;
+
+    return GestureDetector(
+      onTap: () {
+        Navigator.push(
+          context,
+          MaterialPageRoute(
+            builder: (_) => CourseDetailScreen(courseId: course.id),
+          ),
+        );
+      },
+      child: Container(
+        width: 240,
+        margin: const EdgeInsets.only(right: 16),
+        decoration: BoxDecoration(
+          color: surfaceBg,
+          borderRadius: BorderRadius.circular(20),
+          border: Border.all(color: progressColor.withValues(alpha: 0.3)),
+        ),
+        child: Padding(
+          padding: const EdgeInsets.all(16),
+          child: Row(
+            children: [
+              // Course thumbnail
+              Container(
+                width: 80,
+                height: 80,
+                decoration: BoxDecoration(
+                  borderRadius: BorderRadius.circular(16),
+                  color: colorScheme.surface,
+                  image: course.thumbnailUrl != null
+                      ? DecorationImage(
+                          image: NetworkImage(course.thumbnailUrl!),
+                          fit: BoxFit.cover,
+                        )
+                      : null,
+                  border: Border.all(color: colorScheme.outlineVariant),
+                ),
+                child: course.thumbnailUrl == null
+                    ? Icon(Icons.school, size: 32, color: progressColor)
+                    : null,
+              ),
+              const SizedBox(width: 16),
+              // Info section
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  mainAxisAlignment: MainAxisAlignment.center,
+                  children: [
+                    Text(
+                      course.title,
+                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.bold,
+                        fontSize: 14,
+                        height: 1.2,
+                      ),
+                      maxLines: 2,
+                      overflow: TextOverflow.ellipsis,
+                    ),
+                    const SizedBox(height: 4),
+                    Row(
+                      children: [
+                        Container(
+                          padding: const EdgeInsets.symmetric(
+                            horizontal: 8,
+                            vertical: 2,
+                          ),
+                          decoration: BoxDecoration(
+                            color: progressColor.withValues(alpha: 0.1),
+                            borderRadius: BorderRadius.circular(8),
+                          ),
+                          child: Text(
+                            localizedCourseLevel(course.level),
+                            style: TextStyle(
+                              fontSize: 10,
+                              fontWeight: FontWeight.w600,
+                              color: progressColor,
+                            ),
+                          ),
+                        ),
+                        const SizedBox(width: 8),
+                        Text(
+                          'profile.lessonsCount'.tr(
+                            namedArgs: {'count': '${course.totalLessons}'},
+                          ),
+                          style: Theme.of(context).textTheme.bodySmall
+                              ?.copyWith(
+                                color: AppColorRoles.textSecondary(isDark),
+                              ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 8),
+                    // Progress bar
+                    Stack(
+                      children: [
+                        Container(
+                          height: 6,
+                          decoration: BoxDecoration(
+                            color: progressColor.withValues(alpha: 0.15),
+                            borderRadius: BorderRadius.circular(3),
+                          ),
+                        ),
+                        FractionallySizedBox(
+                          widthFactor: progress / 100,
+                          child: Container(
+                            height: 6,
+                            decoration: BoxDecoration(
+                              gradient: LinearGradient(
+                                colors: [
+                                  progressColor,
+                                  progressColor.withValues(alpha: 0.7),
+                                ],
+                              ),
+                              borderRadius: BorderRadius.circular(3),
+                            ),
+                          ),
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 4),
+                    Row(
+                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                      children: [
+                        Expanded(
+                          child: Text(
+                            '${progress.toInt()}%',
+                            style: TextStyle(
+                              fontSize: 11,
+                              fontWeight: FontWeight.w600,
+                              color: progressColor,
+                            ),
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis,
+                          ),
+                        ),
+                        Container(
+                          padding: const EdgeInsets.all(5),
+                          decoration: BoxDecoration(
+                            gradient: LinearGradient(
+                              colors: [
+                                progressColor,
+                                progressColor.withValues(alpha: 0.8),
+                              ],
+                            ),
+                            shape: BoxShape.circle,
+                            boxShadow: [
+                              BoxShadow(
+                                color: progressColor.withValues(alpha: 0.4),
+                                blurRadius: 0,
+                                offset: const Offset(0, 2),
+                              ),
+                            ],
+                          ),
+                          child: Icon(
+                            Icons.play_arrow_rounded,
+                            size: 16,
+                            color: AppColors.surfaceLight,
+                          ),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/featured_courses_section.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/featured_courses_section.dart
new file mode 100644
index 00000000..e7038935
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/featured_courses_section.dart
@@ -0,0 +1,489 @@
+import 'package:cached_network_image/cached_network_image.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/widgets.dart';
+import 'package:lexilingo_app/features/course/domain/entities/course_entity.dart';
+import 'package:lexilingo_app/features/course/presentation/screens/course_detail_screen.dart';
+import 'package:lexilingo_app/features/course/presentation/utils/course_thumbnail_resolver.dart';
+import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/course_level_helpers.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_ui_components.dart';
+
+class FeaturedCoursesSection extends StatelessWidget {
+  const FeaturedCoursesSection({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final provider = context.watch<HomeProvider>();
+
+    // Show skeleton loading while courses are loading
+    if (provider.isLoading && provider.featuredCourses.isEmpty) {
+      return SizedBox(
+        height: 220,
+        child: ListView.builder(
+          scrollDirection: Axis.horizontal,
+          padding: const EdgeInsets.symmetric(horizontal: 16),
+          itemCount: 3,
+          itemBuilder: (context, index) {
+            return Container(
+              width: 240,
+              margin: const EdgeInsets.only(right: 16),
+              child: const CardSkeleton(isHorizontal: false),
+            );
+          },
+        ),
+      );
+    }
+
+    if (provider.featuredCourses.isEmpty) {
+      return _FeaturedCoursesEmptyState(provider: provider);
+    }
+
+    return SizedBox(
+      height: 220,
+      child: ListView.builder(
+        scrollDirection: Axis.horizontal,
+        padding: const EdgeInsets.symmetric(horizontal: 16),
+        itemCount: provider.featuredCourses.length,
+        itemBuilder: (context, index) {
+          final course = provider.featuredCourses[index];
+          // Staggered animation for featured courses
+          return AnimatedListItem(
+            index: index,
+            duration: const Duration(milliseconds: 400),
+            delayPerItem: const Duration(milliseconds: 100),
+            beginOffset: const Offset(0, 60),
+            child: _CourseCard(course: course),
+          );
+        },
+      ),
+    );
+  }
+}
+
+class _FeaturedCoursesEmptyState extends StatelessWidget {
+  final HomeProvider provider;
+
+  const _FeaturedCoursesEmptyState({required this.provider});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final primary = AppColorRoles.primary(isDark);
+
+    return SizedBox(
+      height: 220,
+      child: Container(
+        margin: const EdgeInsets.symmetric(horizontal: 16),
+        padding: const EdgeInsets.all(18),
+        decoration: BoxDecoration(
+          color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+          borderRadius: BorderRadius.circular(20),
+          border: Border.all(
+            color: primary.withValues(alpha: isDark ? 0.22 : 0.16),
+          ),
+        ),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Container(
+              width: 44,
+              height: 44,
+              decoration: BoxDecoration(
+                color: primary.withValues(alpha: 0.12),
+                borderRadius: BorderRadius.circular(12),
+              ),
+              child: Icon(Icons.auto_stories_rounded, size: 24, color: primary),
+            ),
+            const SizedBox(height: 12),
+            Text(
+              'home.noFeaturedCourses'.tr(),
+              style: Theme.of(
+                context,
+              ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w700),
+            ),
+            const SizedBox(height: 6),
+            Text(
+              'home.noFeaturedCoursesDescription'.tr(),
+              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: AppColorRoles.textMuted(isDark),
+                height: 1.35,
+              ),
+            ),
+            const Spacer(),
+            Row(
+              children: [
+                FilledButton.icon(
+                  onPressed: () => provider.loadFeaturedCourses(),
+                  icon: const Icon(Icons.refresh_rounded, size: 18),
+                  label: Text('home.reload'.tr()),
+                ),
+                const SizedBox(width: 10),
+                TextButton(
+                  onPressed: () => provider.refreshData(),
+                  child: Text('home.refreshData'.tr()),
+                ),
+              ],
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _CourseCard extends StatelessWidget {
+  final CourseEntity course;
+
+  const _CourseCard({required this.course});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final levelColor = getLevelColor(course.level, isDark: isDark);
+
+    return GestureDetector(
+      onTap: () {
+        Navigator.push(
+          context,
+          MaterialPageRoute(
+            builder: (_) => CourseDetailScreen(
+              courseId: course.id,
+              heroTag: 'featured-course-image-${course.id}',
+              initialThumbnailUrl: course.thumbnailUrl,
+              fallbackThumbnailUrl: courseFallbackThumbnailUrl(course),
+            ),
+          ),
+        );
+      },
+      child: Container(
+        width: 240,
+        margin: const EdgeInsets.only(right: 16),
+        decoration: BoxDecoration(
+          color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+          borderRadius: BorderRadius.circular(24),
+          border: Border.all(
+            color: isDark
+                ? Colors.white.withValues(alpha: 0.1)
+                : levelColor.withValues(alpha: 0.25),
+            width: 1,
+          ),
+        ),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // Hero animation for course thumbnail
+            Hero(
+              tag: 'featured-course-image-${course.id}',
+              child: ClipRRect(
+                borderRadius: const BorderRadius.vertical(
+                  top: Radius.circular(24),
+                ),
+                child: Stack(
+                  children: [
+                    Positioned.fill(
+                      child: _FeaturedCourseThumbnail(
+                        course: course,
+                        levelColor: levelColor,
+                      ),
+                    ),
+                    // Gradient overlay
+                    Container(
+                      height: 110,
+                      decoration: BoxDecoration(
+                        gradient: LinearGradient(
+                          begin: Alignment.topCenter,
+                          end: Alignment.bottomCenter,
+                          colors: [
+                            Colors.transparent,
+                            Colors.black.withValues(alpha: 0.6),
+                          ],
+                        ),
+                      ),
+                    ),
+                    // Level badge - top left
+                    Positioned(
+                      top: 12,
+                      left: 12,
+                      child: Container(
+                        padding: const EdgeInsets.symmetric(
+                          horizontal: 12,
+                          vertical: 6,
+                        ),
+                        decoration: BoxDecoration(
+                          gradient: LinearGradient(
+                            colors: [
+                              levelColor,
+                              levelColor.withValues(alpha: 0.85),
+                            ],
+                          ),
+                          borderRadius: BorderRadius.circular(20),
+                          boxShadow: [
+                            BoxShadow(
+                              color: levelColor.withValues(alpha: 0.5),
+                              blurRadius: 8,
+                              offset: const Offset(0, 3),
+                            ),
+                          ],
+                        ),
+                        child: Text(
+                          localizedCourseLevel(course.level),
+                          style: TextStyle(
+                            color: AppColors.surfaceLight,
+                            fontSize: 12,
+                            fontWeight: FontWeight.bold,
+                            letterSpacing: 0.5,
+                          ),
+                        ),
+                      ),
+                    ),
+                    // XP badge - top right
+                    Positioned(
+                      top: 12,
+                      right: 12,
+                      child: Container(
+                        padding: const EdgeInsets.symmetric(
+                          horizontal: 10,
+                          vertical: 5,
+                        ),
+                        decoration: BoxDecoration(
+                          gradient: const LinearGradient(
+                            colors: [AppColors.orange, AppColors.orange],
+                          ),
+                          borderRadius: BorderRadius.circular(20),
+                          boxShadow: [
+                            BoxShadow(
+                              color: const Color(
+                                0xFFF59E0B,
+                              ).withValues(alpha: 0.4),
+                              blurRadius: 6,
+                              offset: const Offset(0, 2),
+                            ),
+                          ],
+                        ),
+                        child: Row(
+                          mainAxisSize: MainAxisSize.min,
+                          children: [
+                            Icon(
+                              Icons.star_rounded,
+                              size: 14,
+                              color: AppColors.surfaceLight,
+                            ),
+                            const SizedBox(width: 4),
+                            Text(
+                              'profile.xpValue'.tr(
+                                namedArgs: {'xp': '${course.totalXp}'},
+                              ),
+                              style: TextStyle(
+                                color: AppColors.surfaceLight,
+                                fontSize: 11,
+                                fontWeight: FontWeight.bold,
+                              ),
+                            ),
+                          ],
+                        ),
+                      ),
+                    ),
+                    // Course title overlay at bottom
+                    Positioned(
+                      bottom: 12,
+                      left: 12,
+                      right: 12,
+                      child: Text(
+                        course.title,
+                        style: TextStyle(
+                          color: AppColors.surfaceLight,
+                          fontSize: 16,
+                          fontWeight: FontWeight.bold,
+                          shadows: [
+                            Shadow(
+                              color: AppColors.backgroundDark.withValues(
+                                alpha: 0.75,
+                              ),
+                              blurRadius: 4,
+                            ),
+                          ],
+                        ),
+                        maxLines: 2,
+                        overflow: TextOverflow.ellipsis,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            // Bottom section with info and action
+            Expanded(
+              child: Padding(
+                padding: const EdgeInsets.symmetric(
+                  horizontal: 14,
+                  vertical: 12,
+                ),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                  children: [
+                    // Info chips row
+                    Row(
+                      children: [
+                        _InfoChip(
+                          icon: Icons.menu_book_rounded,
+                          label: 'profile.lessonsCount'.tr(
+                            namedArgs: {'count': '${course.totalLessons}'},
+                          ),
+                          color: AppColorRoles.primary(isDark),
+                        ),
+                        const SizedBox(width: 8),
+                        _InfoChip(
+                          icon: Icons.translate_rounded,
+                          label: course.language,
+                          color: AppColors.purple,
+                        ),
+                      ],
+                    ),
+                    const SizedBox(height: 8),
+                    // Action button
+                    Container(
+                      width: double.infinity,
+                      padding: const EdgeInsets.symmetric(vertical: 10),
+                      decoration: BoxDecoration(
+                        color: levelColor,
+                        borderRadius: BorderRadius.circular(14),
+                        border: Border.all(
+                          color: levelColor.withValues(alpha: 0.6),
+                        ),
+                      ),
+                      child: Row(
+                        mainAxisAlignment: MainAxisAlignment.center,
+                        children: [
+                          Icon(
+                            Icons.play_circle_filled_rounded,
+                            size: 20,
+                            color: AppColors.surfaceLight,
+                          ),
+                          SizedBox(width: 8),
+                          Text(
+                            'home.startLearning'.tr(),
+                            style: TextStyle(
+                              color: AppColors.surfaceLight,
+                              fontSize: 14,
+                              fontWeight: FontWeight.bold,
+                              letterSpacing: 0.3,
+                            ),
+                          ),
+                        ],
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _FeaturedCourseThumbnail extends StatelessWidget {
+  final CourseEntity course;
+  final Color levelColor;
+  final int index;
+
+  const _FeaturedCourseThumbnail({
+    required this.course,
+    required this.levelColor,
+    this.index = 0,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final candidates = buildCourseCardThumbnailCandidates(course);
+    if (index >= candidates.length) {
+      return _FeaturedCourseThumbnailPlaceholder(levelColor: levelColor);
+    }
+
+    return CachedNetworkImage(
+      imageUrl: candidates[index],
+      fit: BoxFit.cover,
+      placeholder: (_, __) =>
+          Container(color: levelColor.withValues(alpha: 0.1)),
+      errorWidget: (_, __, ___) => _FeaturedCourseThumbnail(
+        course: course,
+        levelColor: levelColor,
+        index: index + 1,
+      ),
+    );
+  }
+}
+
+class _FeaturedCourseThumbnailPlaceholder extends StatelessWidget {
+  final Color levelColor;
+
+  const _FeaturedCourseThumbnailPlaceholder({required this.levelColor});
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      color: levelColor.withValues(alpha: 0.1),
+      alignment: Alignment.center,
+      child: Container(
+        padding: const EdgeInsets.all(20),
+        decoration: BoxDecoration(
+          color: Theme.of(context).colorScheme.surface.withValues(alpha: 0.15),
+          shape: BoxShape.circle,
+          border: Border.all(
+            color: Theme.of(context).colorScheme.surface.withValues(alpha: 0.3),
+            width: 2,
+          ),
+        ),
+        child: const Icon(
+          Icons.school_rounded,
+          size: 40,
+          color: AppColors.surfaceLight,
+        ),
+      ),
+    );
+  }
+}
+
+class _InfoChip extends StatelessWidget {
+  final IconData icon;
+  final String label;
+  final Color color;
+
+  const _InfoChip({
+    required this.icon,
+    required this.label,
+    required this.color,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: 0.1),
+        borderRadius: BorderRadius.circular(10),
+        border: Border.all(color: color.withValues(alpha: 0.2), width: 1.5),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(icon, size: 14, color: color),
+          const SizedBox(width: 5),
+          Text(
+            label,
+            style: TextStyle(
+              fontSize: 11,
+              fontWeight: FontWeight.w600,
+              color: color,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/home_header.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/home_header.dart
new file mode 100644
index 00000000..0a5a8da3
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/home_header.dart
@@ -0,0 +1,43 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/features/auth/presentation/providers/auth_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_ui_components.dart';
+import 'package:lexilingo_app/features/level/level.dart';
+import 'package:lexilingo_app/features/notifications/presentation/pages/notifications_page.dart';
+import 'package:lexilingo_app/features/notifications/presentation/providers/notification_provider.dart';
+
+class HomeHeader extends StatelessWidget {
+  const HomeHeader({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final authProvider = Provider.of<AuthProvider>(context);
+    // Get user display name from AuthProvider
+    final user = authProvider.currentUser;
+    final displayName = user?.displayName.isNotEmpty == true
+        ? user!.displayName
+        : user?.username ?? 'profile.guestUser'.tr();
+
+    return Consumer2<NotificationProvider, LevelProvider>(
+      builder: (context, notificationProvider, levelProvider, child) {
+        final totalXP = levelProvider.levelStatus.totalXP;
+        return PersonalizedGreetingHeader(
+          userName: displayName,
+          totalXP: totalXP,
+          avatarUrl: user?.avatarUrl,
+          notificationCount: notificationProvider.unreadCount,
+          onNotificationTap: () {
+            Navigator.push(
+              context,
+              MaterialPageRoute(builder: (_) => const NotificationsPage()),
+            );
+          },
+          onAvatarTap: () {
+            // Navigate to profile or settings
+          },
+        );
+      },
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/home_skeleton_loading.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/home_skeleton_loading.dart
new file mode 100644
index 00000000..a62bdec8
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/home_skeleton_loading.dart
@@ -0,0 +1,72 @@
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/widgets/widgets.dart';
+
+/// Skeleton loading state for home page
+class HomeSkeletonLoading extends StatelessWidget {
+  const HomeSkeletonLoading({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return SingleChildScrollView(
+      padding: const EdgeInsets.only(bottom: 24.0),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          // Header skeleton
+          ShimmerContainer(
+            child: Padding(
+              padding: const EdgeInsets.all(16.0),
+              child: Row(
+                children: [
+                  const SkeletonCircle(size: 48),
+                  const SizedBox(width: 12),
+                  Column(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      SkeletonText(width: 150, height: 14),
+                      SizedBox(height: 6),
+                      SkeletonText(width: 100, height: 12),
+                      SizedBox(height: 6),
+                      SkeletonText(width: 120, height: 18),
+                    ],
+                  ),
+                  const Spacer(),
+                  const SkeletonCircle(size: 40),
+                ],
+              ),
+            ),
+          ),
+          const SizedBox(height: 16),
+          // Streak card skeleton
+          const SkeletonProgressStats(),
+          const SizedBox(height: 24),
+          // Daily goal skeleton
+          ShimmerContainer(
+            child: Container(
+              margin: EdgeInsets.symmetric(horizontal: 16),
+              height: 120,
+              decoration: BoxDecoration(
+                color: Theme.of(context).colorScheme.surface,
+                borderRadius: BorderRadius.circular(16),
+              ),
+            ),
+          ),
+          const SizedBox(height: 24),
+          // Section title skeleton
+          Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 16.0),
+            child: ShimmerContainer(
+              child: SkeletonText(width: 150, height: 20),
+            ),
+          ),
+          const SizedBox(height: 12),
+          // Courses skeleton
+          const SkeletonHomeSection(),
+          const SizedBox(height: 24),
+          // Another section
+          const SkeletonHomeSection(),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/level_and_daily_goal_row.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/level_and_daily_goal_row.dart
new file mode 100644
index 00000000..c93ae1b5
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/level_and_daily_goal_row.dart
@@ -0,0 +1,586 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/glassmorphic_components.dart'
+    as glass;
+import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/level/level.dart';
+import 'package:lexilingo_app/features/user/presentation/providers/settings_provider.dart';
+
+void _showDailyGoalSheet(
+  BuildContext context,
+  HomeProvider homeProvider,
+) async {
+  final settings = context.read<SettingsProvider>();
+  final settingsState = settings.settings;
+
+  if (settingsState == null) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(content: Text('home.dailyGoalSettingsPending'.tr())),
+    );
+    return;
+  }
+
+  await showModalBottomSheet<void>(
+    context: context,
+    isScrollControlled: true,
+    backgroundColor: Colors.transparent,
+    builder: (sheetContext) {
+      final isDark = Theme.of(sheetContext).brightness == Brightness.dark;
+      final colorScheme = Theme.of(sheetContext).colorScheme;
+      final primaryColor = AppColorRoles.primary(isDark);
+
+      return Consumer<SettingsProvider>(
+        builder: (sheetContext, settingsProvider, _) {
+          return Container(
+            padding: const EdgeInsets.fromLTRB(24, 12, 24, 32),
+            decoration: BoxDecoration(
+              color: Theme.of(sheetContext).scaffoldBackgroundColor,
+              borderRadius: const BorderRadius.vertical(
+                top: Radius.circular(24),
+              ),
+            ),
+            child: SingleChildScrollView(
+              child: Column(
+                mainAxisSize: MainAxisSize.min,
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Center(
+                    child: Container(
+                      width: 40,
+                      height: 4,
+                      margin: const EdgeInsets.only(bottom: 20),
+                      decoration: BoxDecoration(
+                        color: colorScheme.outlineVariant,
+                        borderRadius: BorderRadius.circular(999),
+                      ),
+                    ),
+                  ),
+                  Text(
+                    'home.dailyGoal'.tr(),
+                    style: Theme.of(sheetContext).textTheme.headlineSmall
+                        ?.copyWith(fontWeight: FontWeight.w800),
+                  ),
+                  const SizedBox(height: 6),
+                  Text(
+                    'home.dailyGoalDescription'.tr(),
+                    style: Theme.of(sheetContext).textTheme.bodyMedium
+                        ?.copyWith(color: AppColorRoles.textMuted(isDark)),
+                  ),
+                  const SizedBox(height: 16),
+                  Container(
+                    width: double.infinity,
+                    padding: const EdgeInsets.all(16),
+                    decoration: BoxDecoration(
+                      gradient: LinearGradient(
+                        colors: [
+                          primaryColor,
+                          primaryColor.withValues(alpha: 0.72),
+                        ],
+                      ),
+                      borderRadius: BorderRadius.circular(18),
+                    ),
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Text(
+                          '${homeProvider.dailyXP}/${settingsProvider.dailyGoalXP} XP',
+                          style: Theme.of(sheetContext).textTheme.headlineSmall
+                              ?.copyWith(
+                                color: colorScheme.onPrimary,
+                                fontWeight: FontWeight.w800,
+                              ),
+                        ),
+                        const SizedBox(height: 4),
+                        Text(
+                          'settings.goal_progress'.tr(
+                            namedArgs: {
+                              'percent':
+                                  '${(homeProvider.dailyProgressPercentage * 100).toInt()}',
+                            },
+                          ),
+                          style: Theme.of(sheetContext).textTheme.bodyMedium
+                              ?.copyWith(
+                                color: colorScheme.onPrimary.withValues(
+                                  alpha: 0.88,
+                                ),
+                              ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  const SizedBox(height: 16),
+                  ...SettingsProvider.dailyGoalPresets.map((goal) {
+                    final xp = goal['xp'] as int;
+                    final isSelected = settingsProvider.dailyGoalXP == xp;
+
+                    return Padding(
+                      padding: const EdgeInsets.only(bottom: 10),
+                      child: InkWell(
+                        borderRadius: BorderRadius.circular(16),
+                        onTap: () async {
+                          await settingsProvider.updateDailyGoal(xp);
+                          if (!sheetContext.mounted) return;
+
+                          if (settingsProvider.error == null) {
+                            homeProvider.updateDailyGoalTarget(xp);
+                            Navigator.of(sheetContext).pop();
+                            ScaffoldMessenger.of(context).showSnackBar(
+                              SnackBar(
+                                content: Text(
+                                  'settings.goal_updated'.tr(
+                                    namedArgs: {'xp': '$xp'},
+                                  ),
+                                ),
+                              ),
+                            );
+                          } else {
+                            ScaffoldMessenger.of(sheetContext).showSnackBar(
+                              SnackBar(content: Text(settingsProvider.error!)),
+                            );
+                          }
+                        },
+                        child: AnimatedContainer(
+                          duration: const Duration(milliseconds: 180),
+                          padding: const EdgeInsets.symmetric(
+                            horizontal: 14,
+                            vertical: 14,
+                          ),
+                          decoration: BoxDecoration(
+                            color: isSelected
+                                ? primaryColor.withValues(alpha: 0.12)
+                                : colorScheme.surfaceContainerHighest,
+                            borderRadius: BorderRadius.circular(16),
+                            border: Border.all(
+                              color: isSelected
+                                  ? primaryColor
+                                  : colorScheme.outlineVariant,
+                              width: isSelected ? 2 : 1,
+                            ),
+                          ),
+                          child: Row(
+                            children: [
+                              Container(
+                                width: 42,
+                                height: 42,
+                                decoration: BoxDecoration(
+                                  color: isSelected
+                                      ? primaryColor
+                                      : primaryColor.withValues(alpha: 0.12),
+                                  borderRadius: BorderRadius.circular(12),
+                                ),
+                                child: Icon(
+                                  goal['icon'] as IconData,
+                                  color: isSelected
+                                      ? colorScheme.onPrimary
+                                      : primaryColor,
+                                ),
+                              ),
+                              const SizedBox(width: 12),
+                              Expanded(
+                                child: Column(
+                                  crossAxisAlignment: CrossAxisAlignment.start,
+                                  children: [
+                                    Text(
+                                      '${(goal['label'] as String).tr()} • $xp XP',
+                                      style: Theme.of(sheetContext)
+                                          .textTheme
+                                          .titleMedium
+                                          ?.copyWith(
+                                            fontWeight: FontWeight.w700,
+                                          ),
+                                    ),
+                                    const SizedBox(height: 2),
+                                    Text(
+                                      (goal['description'] as String).tr(),
+                                      style: Theme.of(sheetContext)
+                                          .textTheme
+                                          .bodySmall
+                                          ?.copyWith(
+                                            color: AppColorRoles.textMuted(
+                                              isDark,
+                                            ),
+                                          ),
+                                    ),
+                                  ],
+                                ),
+                              ),
+                              if (isSelected)
+                                Icon(Icons.check_circle, color: primaryColor),
+                            ],
+                          ),
+                        ),
+                      ),
+                    );
+                  }),
+                ],
+              ),
+            ),
+          );
+        },
+      );
+    },
+  );
+}
+
+class LevelAndDailyGoalRow extends StatelessWidget {
+  const LevelAndDailyGoalRow({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final provider = context.watch<HomeProvider>();
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16.0),
+      child: LayoutBuilder(
+        builder: (context, constraints) {
+          final isNarrow = constraints.maxWidth < 360;
+
+          if (isNarrow) {
+            return Column(
+              children: [
+                SizedBox(height: 148, child: LevelProgressCard(compact: true)),
+                const SizedBox(height: 12),
+                SizedBox(
+                  height: 148,
+                  child: _DailyGoalCard(
+                    provider: provider,
+                    compact: true,
+                    margin: EdgeInsets.zero,
+                  ),
+                ),
+              ],
+            );
+          }
+
+          return Row(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Expanded(
+                flex: 6,
+                child: SizedBox(
+                  height: 148,
+                  child: LevelProgressCard(compact: true),
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                flex: 4,
+                child: SizedBox(
+                  height: 148,
+                  child: _DailyGoalCard(
+                    provider: provider,
+                    compact: true,
+                    margin: EdgeInsets.zero,
+                  ),
+                ),
+              ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+}
+
+class _DailyGoalCard extends StatelessWidget {
+  final HomeProvider provider;
+  final bool compact;
+  final EdgeInsetsGeometry? margin;
+
+  const _DailyGoalCard({
+    required this.provider,
+    this.compact = false,
+    this.margin,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    // Use user-configured daily goal from settings; fall back to HomeProvider.
+    final goalXP = context.read<SettingsProvider>().dailyGoalXP;
+    final earnedXP = provider.dailyXP;
+    final percentage = goalXP > 0 ? (earnedXP / goalXP).clamp(0.0, 1.0) : 0.0;
+    final isCompleted = percentage >= 1.0;
+    final colorScheme = Theme.of(context).colorScheme;
+    final accent = AppColorRoles.primary(isDark);
+    final accentDeep = AppColorRoles.primaryDeep(isDark);
+    final surfaceBg = colorScheme.surfaceContainerHighest;
+    final compactBg = isCompleted
+        ? AppColors.greenSuccessBright.withValues(alpha: 0.10)
+        : accent.withValues(alpha: 0.07);
+    final cardPadding = compact ? 14.0 : 20.0;
+    final ringSize = compact ? 58.0 : 70.0;
+    final ringStroke = compact ? 5.0 : 6.0;
+    final titleFontSize = compact ? 16.0 : null;
+    final valueFontSize = compact ? 18.0 : null;
+    final chipFontSize = compact ? 11.0 : 12.0;
+    final badgeIconSize = compact ? 16.0 : 18.0;
+    final ringValueFontSize = compact ? 12.0 : 14.0;
+
+    final borderRadius = BorderRadius.circular(compact ? 16 : 20);
+
+    return Material(
+      color: Colors.transparent,
+      child: Padding(
+        padding: margin ?? const EdgeInsets.symmetric(horizontal: 16),
+        child: InkWell(
+          onTap: () => _showDailyGoalSheet(context, provider),
+          borderRadius: borderRadius,
+          child: Ink(
+            padding: EdgeInsets.all(cardPadding),
+            decoration: BoxDecoration(
+              color: compact ? compactBg : surfaceBg,
+              borderRadius: borderRadius,
+              border: Border.all(
+                color: isCompleted
+                    ? AppColors.greenSuccessBright.withValues(alpha: 0.3)
+                    : accent.withValues(alpha: 0.35),
+              ),
+            ),
+            child: compact
+                ? Column(
+                    crossAxisAlignment: CrossAxisAlignment.center,
+                    mainAxisAlignment: MainAxisAlignment.center,
+                    children: [
+                      Row(
+                        mainAxisAlignment: MainAxisAlignment.center,
+                        children: [
+                          Container(
+                            padding: const EdgeInsets.all(5),
+                            decoration: BoxDecoration(
+                              color: colorScheme.surface,
+                              borderRadius: BorderRadius.circular(8),
+                            ),
+                            child: Icon(
+                              isCompleted ? Icons.emoji_events : Icons.bolt,
+                              color: isCompleted
+                                  ? AppColors.greenSuccessBright
+                                  : accent,
+                              size: badgeIconSize,
+                            ),
+                          ),
+                          const SizedBox(width: 8),
+                          Flexible(
+                            child: Text(
+                              'home.dailyGoal'.tr(),
+                              maxLines: 1,
+                              overflow: TextOverflow.ellipsis,
+                              style: Theme.of(context).textTheme.titleSmall
+                                  ?.copyWith(
+                                    fontWeight: FontWeight.bold,
+                                    fontSize: 15,
+                                    color: isCompleted
+                                        ? AppColors.greenSuccess
+                                        : accentDeep,
+                                  ),
+                            ),
+                          ),
+                        ],
+                      ),
+                      const SizedBox(height: 10),
+                      Expanded(
+                        child: Center(
+                          child: Container(
+                            decoration: BoxDecoration(
+                              shape: BoxShape.circle,
+                              color: colorScheme.surface,
+                            ),
+                            child: glass.AnimatedProgressRing(
+                              progress: percentage.clamp(0.0, 1.0),
+                              size: ringSize + 10,
+                              strokeWidth: ringStroke,
+                              gradientColors: isCompleted
+                                  ? const [
+                                      AppColors.greenSuccessBright,
+                                      AppColors.greenSuccess,
+                                    ]
+                                  : AppColorRoles.primaryGradient(isDark),
+                              child: Column(
+                                mainAxisAlignment: MainAxisAlignment.center,
+                                children: [
+                                  if (isCompleted)
+                                    const Icon(
+                                      Icons.check,
+                                      color: AppColors.greenSuccessBright,
+                                      size: 18,
+                                    )
+                                  else
+                                    Text(
+                                      '${(percentage * 100).toInt()}%',
+                                      style: TextStyle(
+                                        fontSize: ringValueFontSize,
+                                        fontWeight: FontWeight.bold,
+                                        color: accent,
+                                      ),
+                                    ),
+                                ],
+                              ),
+                            ),
+                          ),
+                        ),
+                      ),
+                      const SizedBox(height: 8),
+                      Text(
+                        '$earnedXP/$goalXP XP',
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                        style: Theme.of(context).textTheme.titleMedium
+                            ?.copyWith(
+                              fontWeight: FontWeight.bold,
+                              fontSize: 16,
+                              color: isCompleted
+                                  ? AppColors.greenSuccessBright
+                                  : accent,
+                            ),
+                      ),
+                    ],
+                  )
+                : Row(
+                    children: [
+                      // Animated Progress Ring
+                      Container(
+                        padding: const EdgeInsets.all(4),
+                        decoration: BoxDecoration(
+                          shape: BoxShape.circle,
+                          color: colorScheme.surface,
+                        ),
+                        child: glass.AnimatedProgressRing(
+                          progress: percentage.clamp(0.0, 1.0),
+                          size: ringSize,
+                          strokeWidth: ringStroke,
+                          gradientColors: isCompleted
+                              ? const [
+                                  AppColors.greenSuccessBright,
+                                  AppColors.greenSuccess,
+                                ]
+                              : const [AppColors.primary, AppColors.primary],
+                          child: Column(
+                            mainAxisSize: MainAxisSize.min,
+                            children: [
+                              if (isCompleted)
+                                const Icon(
+                                  Icons.check,
+                                  color: AppColors.greenSuccessBright,
+                                  size: 20,
+                                )
+                              else
+                                Text(
+                                  '${(percentage * 100).toInt()}%',
+                                  style: TextStyle(
+                                    fontSize: ringValueFontSize,
+                                    fontWeight: FontWeight.bold,
+                                    color: isCompleted
+                                        ? AppColors.greenSuccessBright
+                                        : AppColors.primary,
+                                  ),
+                                ),
+                            ],
+                          ),
+                        ),
+                      ),
+                      SizedBox(width: compact ? 12 : 20),
+                      // Info
+                      Expanded(
+                        child: Column(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            Row(
+                              children: [
+                                Container(
+                                  padding: EdgeInsets.all(compact ? 5 : 6),
+                                  decoration: BoxDecoration(
+                                    color: colorScheme.surface,
+                                    borderRadius: BorderRadius.circular(8),
+                                  ),
+                                  child: Icon(
+                                    isCompleted
+                                        ? Icons.emoji_events
+                                        : Icons.bolt,
+                                    color: isCompleted
+                                        ? AppColors.greenSuccessBright
+                                        : accent,
+                                    size: badgeIconSize,
+                                  ),
+                                ),
+                                const SizedBox(width: 8),
+                                Expanded(
+                                  child: Text(
+                                    'home.dailyXpGoal'.tr(),
+                                    maxLines: 1,
+                                    overflow: TextOverflow.ellipsis,
+                                    style: Theme.of(context)
+                                        .textTheme
+                                        .titleMedium
+                                        ?.copyWith(
+                                          fontWeight: FontWeight.bold,
+                                          fontSize: titleFontSize,
+                                          color: isCompleted
+                                              ? AppColors.greenSuccess
+                                              : accentDeep,
+                                        ),
+                                  ),
+                                ),
+                              ],
+                            ),
+                            SizedBox(height: compact ? 6 : 8),
+                            Text(
+                              '$earnedXP/$goalXP XP',
+                              style: Theme.of(context).textTheme.headlineSmall
+                                  ?.copyWith(
+                                    fontWeight: FontWeight.bold,
+                                    fontSize: valueFontSize,
+                                    color: isCompleted
+                                        ? AppColors.greenSuccessBright
+                                        : accent,
+                                  ),
+                            ),
+                            SizedBox(height: compact ? 2 : 4),
+                            Container(
+                              padding: EdgeInsets.symmetric(
+                                horizontal: compact ? 8 : 10,
+                                vertical: compact ? 3 : 4,
+                              ),
+                              decoration: BoxDecoration(
+                                color: colorScheme.surface,
+                                borderRadius: BorderRadius.circular(12),
+                              ),
+                              child: Row(
+                                mainAxisSize: MainAxisSize.min,
+                                children: [
+                                  Icon(
+                                    isCompleted
+                                        ? Icons.celebration
+                                        : Icons.trending_up,
+                                    size: 14,
+                                    color: isCompleted
+                                        ? AppColors.greenSuccessBright
+                                        : accent,
+                                  ),
+                                  const SizedBox(width: 4),
+                                  Text(
+                                    isCompleted
+                                        ? 'home.goalCompleted'.tr()
+                                        : 'home.keepGoing'.tr(),
+                                    style: TextStyle(
+                                      fontSize: chipFontSize,
+                                      fontWeight: FontWeight.w600,
+                                      color: isCompleted
+                                          ? AppColors.greenSuccessBright
+                                          : accent,
+                                    ),
+                                  ),
+                                ],
+                              ),
+                            ),
+                          ],
+                        ),
+                      ),
+                    ],
+                  ),
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/quick_actions_grid.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/quick_actions_grid.dart
new file mode 100644
index 00000000..ed673727
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/quick_actions_grid.dart
@@ -0,0 +1,219 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/pages/vocab_library_page.dart';
+
+/// Quick Actions - Horizontal scrollable section with circular buttons
+class QuickActionsGrid extends StatelessWidget {
+  const QuickActionsGrid({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+    // Keep all dark-mode quick actions in a consistent neon range.
+    const neonDarkActionColors = <Color>[
+      Color(0xFF00E5FF), // Practice Lab
+      Color(0xFFFF3131), // YouTube
+      Color(0xFFFC1AD3), // News
+      Color(0xFFFFA319), // Games
+      Color(0xFF35FF0D), // Podcast
+      Color(0xFF8B5CFF), // Books (neon purple)
+      Color(0xFFFF369E), // Vocabulary
+    ];
+
+    final quickActions = [
+      {
+        'icon': Icons.science_rounded,
+        'label': 'practiceLab.shortTitle',
+        'color': isDark ? neonDarkActionColors[0] : AppColors.primary,
+        'bgColor': (isDark ? neonDarkActionColors[0] : AppColors.primary)
+            .withValues(alpha: isDark ? 0.16 : 0.1),
+        'route': '/practice-lab',
+      },
+      {
+        'icon': Icons.smart_display,
+        'label': 'home.youtube',
+        'color': isDark ? neonDarkActionColors[1] : AppColors.dangerGradient[0],
+        'bgColor':
+            (isDark ? neonDarkActionColors[1] : AppColors.dangerGradient[0])
+                .withValues(alpha: isDark ? 0.16 : 0.1),
+        'route': '/youtube',
+      },
+      {
+        'icon': Icons.article,
+        'label': 'home.news',
+        'color': isDark ? neonDarkActionColors[2] : AppColors.teal,
+        'bgColor': (isDark ? neonDarkActionColors[2] : AppColors.teal)
+            .withValues(alpha: isDark ? 0.16 : 0.1),
+        'route': '/news',
+      },
+      {
+        'icon': Icons.sports_esports,
+        'label': 'home.games',
+        'color': isDark ? neonDarkActionColors[3] : AppColors.purple,
+        'bgColor': (isDark ? neonDarkActionColors[3] : AppColors.purple)
+            .withValues(alpha: isDark ? 0.16 : 0.1),
+        'route': '/games',
+      },
+      {
+        'icon': Icons.podcasts,
+        'label': 'home.podcast',
+        'color': isDark ? neonDarkActionColors[4] : accent,
+        'bgColor': (isDark ? neonDarkActionColors[4] : accent).withValues(
+          alpha: isDark ? 0.16 : 0.12,
+        ),
+        'route': '/podcast',
+      },
+      {
+        'icon': Icons.menu_book_rounded,
+        'label': 'home.books',
+        'color': isDark ? neonDarkActionColors[5] : AppColors.purpleLight,
+        'bgColor': (isDark ? neonDarkActionColors[5] : AppColors.purple)
+            .withValues(alpha: isDark ? 0.16 : 0.1),
+        'route': '/books',
+      },
+      {
+        'icon': Icons.style,
+        'label': 'home.vocabulary',
+        'color': isDark ? neonDarkActionColors[6] : AppColors.orange,
+        'bgColor': (isDark ? neonDarkActionColors[6] : AppColors.warning)
+            .withValues(alpha: isDark ? 0.16 : 0.1),
+        'route': '/vocab',
+      },
+    ];
+
+    const spacing = 12.0;
+
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16),
+      child: LayoutBuilder(
+        builder: (context, constraints) {
+          final crossAxisCount = constraints.maxWidth >= 960
+              ? quickActions.length
+              : constraints.maxWidth >= 640
+              ? 4
+              : 3;
+          final tileWidth =
+              (constraints.maxWidth - spacing * (crossAxisCount - 1)) /
+              crossAxisCount;
+          // Scale the icon (and tile height) with tile width instead of a
+          // fixed aspect ratio, so narrow screens don't overflow vertically.
+          final iconSize = (tileWidth * 0.42).clamp(34.0, 44.0);
+          final tileHeight = iconSize + 56;
+
+          return GridView.builder(
+            shrinkWrap: true,
+            physics: const NeverScrollableScrollPhysics(),
+            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
+              crossAxisCount: crossAxisCount,
+              mainAxisSpacing: spacing,
+              crossAxisSpacing: spacing,
+              mainAxisExtent: tileHeight,
+            ),
+            itemCount: quickActions.length,
+            itemBuilder: (context, index) {
+              final action = quickActions[index];
+              return _QuickActionChip(
+                icon: action['icon'] as IconData,
+                label: (action['label'] as String).tr(),
+                color: action['color'] as Color,
+                bgColor: action['bgColor'] as Color,
+                iconSize: iconSize,
+                onTap: () {
+                  final route = action['route'] as String;
+                  if (route == '/vocab') {
+                    Navigator.push(
+                      context,
+                      MaterialPageRoute(
+                        builder: (_) => const VocabLibraryPage(),
+                      ),
+                    );
+                  } else {
+                    Navigator.pushNamed(context, route);
+                  }
+                },
+              );
+            },
+          );
+        },
+      ),
+    );
+  }
+}
+
+class _QuickActionChip extends StatelessWidget {
+  final IconData icon;
+  final String label;
+  final Color color;
+  final Color bgColor;
+  final VoidCallback onTap;
+  final double iconSize;
+
+  const _QuickActionChip({
+    required this.icon,
+    required this.label,
+    required this.color,
+    required this.bgColor,
+    required this.onTap,
+    this.iconSize = 44,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final fontSize = iconSize <= 38 ? 9.0 : 10.0;
+    return GestureDetector(
+      onTap: onTap,
+      child: Container(
+        padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 12),
+        decoration: BoxDecoration(
+          color: bgColor,
+          borderRadius: BorderRadius.circular(18),
+          border: Border.all(
+            color: color.withValues(alpha: isDark ? 0.5 : 0.35),
+            width: 2,
+          ),
+        ),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Container(
+              width: iconSize,
+              height: iconSize,
+              decoration: BoxDecoration(
+                color: color,
+                borderRadius: BorderRadius.circular(14),
+                boxShadow: [
+                  BoxShadow(
+                    color: color.withValues(alpha: isDark ? 0.5 : 0.35),
+                    blurRadius: 0,
+                    offset: const Offset(0, 4),
+                  ),
+                ],
+              ),
+              child: Icon(
+                icon,
+                color: Theme.of(context).colorScheme.surface,
+                size: iconSize * 0.5,
+              ),
+            ),
+            const SizedBox(height: 10),
+            Text(
+              label,
+              style: TextStyle(
+                fontSize: fontSize,
+                height: 1.1,
+                fontWeight: FontWeight.w700,
+                color: color,
+              ),
+              textAlign: TextAlign.center,
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/section_title.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/section_title.dart
new file mode 100644
index 00000000..bd557a52
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/section_title.dart
@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+class SectionTitle extends StatelessWidget {
+  final String title;
+
+  const SectionTitle({super.key, required this.title});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16.0),
+      child: Text(
+        title,
+        style: Theme.of(context).textTheme.titleLarge?.copyWith(
+          fontWeight: FontWeight.bold,
+          fontSize: 18,
+          color: AppColorRoles.textPrimary(isDark),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/streak_card_section.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/streak_card_section.dart
new file mode 100644
index 00000000..98b7e88e
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/streak_card_section.dart
@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_ui_components.dart';
+import 'package:lexilingo_app/features/progress/presentation/providers/streak_provider.dart';
+import 'package:lexilingo_app/features/progress/presentation/widgets/points_calendar_dialog.dart';
+
+class StreakCardSection extends StatelessWidget {
+  const StreakCardSection({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer2<HomeProvider, StreakProvider>(
+      builder: (context, provider, streakProvider, child) {
+        final streak = streakProvider.streak;
+        final currentStreak = streak?.currentStreak ?? provider.streakDays;
+        final longestStreak = streak?.longestStreak ?? 0;
+        final isActiveToday = streak?.isActiveToday ?? false;
+
+        return Padding(
+          padding: const EdgeInsets.symmetric(horizontal: 16.0),
+          child: AnimatedStreakCard(
+            streakDays: currentStreak,
+            longestStreak: longestStreak,
+            isActiveToday: isActiveToday,
+            weeklyActivity: streak?.weeklyActivity,
+            weeklyProgressPercentages: provider.weeklyProgress.weekProgress
+                .map((day) => day.progressPercentage)
+                .toList(growable: false),
+            onTap: () {
+              if (streak != null) {
+                showPointsCalendarDialog(context, streak);
+              }
+            },
+          ),
+        );
+      },
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_models.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_models.dart
new file mode 100644
index 00000000..20b6aeca
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_models.dart
@@ -0,0 +1,272 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/features/course/domain/entities/course_entity.dart';
+import 'package:lexilingo_app/features/level/domain/entities/proficiency_entity.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/daily_challenge_entity.dart';
+
+enum TodayPlanDestination {
+  vocabularyReview,
+  courseList,
+  games,
+  lexi,
+  voice,
+  news,
+  podcast,
+}
+
+enum TodayPlanTaskType { vocabulary, course, skill, challenge, conversation }
+
+class TodayPlanTask {
+  const TodayPlanTask({
+    required this.type,
+    required this.destination,
+    required this.icon,
+    required this.color,
+    required this.title,
+    required this.subtitle,
+    required this.actionLabel,
+    required this.progress,
+    this.isCompleted = false,
+    this.metaLabel,
+    this.rewardLabel,
+  });
+
+  final TodayPlanTaskType type;
+  final TodayPlanDestination destination;
+  final IconData icon;
+  final Color color;
+  final String title;
+  final String subtitle;
+  final String actionLabel;
+  final double progress;
+  final bool isCompleted;
+  final String? metaLabel;
+  final String? rewardLabel;
+}
+
+class TodayPlanSnapshot {
+  const TodayPlanSnapshot(this.tasks);
+
+  final List<TodayPlanTask> tasks;
+
+  int get completedCount => tasks.where((task) => task.isCompleted).length;
+  int get totalCount => tasks.length;
+  double get progress => totalCount == 0 ? 0 : completedCount / totalCount;
+
+  TodayPlanTask? get nextTask {
+    for (final task in tasks) {
+      if (!task.isCompleted) return task;
+    }
+    return tasks.isEmpty ? null : tasks.first;
+  }
+}
+
+TodayPlanSnapshot buildTodayPlanSnapshot({
+  required List<CourseEntity> enrolledCourses,
+  required List<DailyChallengeEntity> challenges,
+  required List<SkillScore> weakestSkills,
+  int? dueVocabularyCount,
+}) {
+  final tasks = <TodayPlanTask>[];
+
+  tasks.add(_buildVocabularyTask(dueVocabularyCount));
+  tasks.add(_buildCourseTask(enrolledCourses));
+  tasks.add(_buildSkillTask(weakestSkills));
+  tasks.add(_buildChallengeTask(challenges));
+  tasks.add(_buildConversationTask());
+
+  return TodayPlanSnapshot(tasks);
+}
+
+TodayPlanTask _buildVocabularyTask(int? dueCount) {
+  final count = dueCount ?? 0;
+  final hasDueWords = dueCount == null || count > 0;
+
+  return TodayPlanTask(
+    type: TodayPlanTaskType.vocabulary,
+    destination: TodayPlanDestination.vocabularyReview,
+    icon: Icons.style_rounded,
+    color: const Color(0xFFE85D9E),
+    title: 'home.todayPlan.vocabularyTitle'.tr(),
+    subtitle: dueCount == null
+        ? 'home.todayPlan.vocabularyCheckSubtitle'.tr()
+        : count > 0
+        ? 'home.todayPlan.vocabularyDueSubtitle'.tr(
+            namedArgs: {'count': '$count'},
+          )
+        : 'home.todayPlan.vocabularyDoneSubtitle'.tr(),
+    actionLabel: hasDueWords
+        ? 'home.todayPlan.reviewAction'.tr()
+        : 'home.todayPlan.checkAction'.tr(),
+    metaLabel: 'home.todayPlan.vocabularyMeta'.tr(),
+    progress: hasDueWords ? 0 : 1,
+    isCompleted: !hasDueWords,
+  );
+}
+
+TodayPlanTask _buildCourseTask(List<CourseEntity> enrolledCourses) {
+  final course = enrolledCourses
+      .where((item) => (item.userProgress ?? 0) < 1)
+      .cast<CourseEntity?>()
+      .firstWhere((item) => item != null, orElse: () => null);
+
+  if (course == null) {
+    return TodayPlanTask(
+      type: TodayPlanTaskType.course,
+      destination: TodayPlanDestination.courseList,
+      icon: Icons.menu_book_rounded,
+      color: const Color(0xFF2687D9),
+      title: 'home.todayPlan.courseFallbackTitle'.tr(),
+      subtitle: 'home.todayPlan.courseFallbackSubtitle'.tr(),
+      actionLabel: 'home.todayPlan.browseAction'.tr(),
+      metaLabel: 'home.todayPlan.courseMeta'.tr(),
+      progress: 0,
+    );
+  }
+
+  final progress = (course.userProgress ?? 0).clamp(0.0, 1.0);
+
+  return TodayPlanTask(
+    type: TodayPlanTaskType.course,
+    destination: TodayPlanDestination.courseList,
+    icon: Icons.menu_book_rounded,
+    color: const Color(0xFF2687D9),
+    title: course.title,
+    subtitle: 'home.todayPlan.courseSubtitle'.tr(
+      namedArgs: {'level': course.level},
+    ),
+    actionLabel: 'home.todayPlan.continueAction'.tr(),
+    metaLabel: 'home.todayPlan.courseProgress'.tr(
+      namedArgs: {'percent': '${(progress * 100).round()}'},
+    ),
+    rewardLabel: course.totalXp > 0 ? '+${course.totalXp} XP' : null,
+    progress: progress,
+    isCompleted: progress >= 1,
+  );
+}
+
+TodayPlanTask _buildSkillTask(List<SkillScore> weakestSkills) {
+  final skill = weakestSkills.isEmpty ? null : weakestSkills.first;
+
+  if (skill == null) {
+    return TodayPlanTask(
+      type: TodayPlanTaskType.skill,
+      destination: TodayPlanDestination.voice,
+      icon: Icons.mic_rounded,
+      color: const Color(0xFF18A999),
+      title: 'home.todayPlan.skillFallbackTitle'.tr(),
+      subtitle: 'home.todayPlan.skillFallbackSubtitle'.tr(),
+      actionLabel: 'home.todayPlan.practiceAction'.tr(),
+      metaLabel: 'home.todayPlan.skillMeta'.tr(),
+      progress: 0,
+    );
+  }
+
+  final destination = _destinationForSkill(skill.skill);
+
+  return TodayPlanTask(
+    type: TodayPlanTaskType.skill,
+    destination: destination,
+    icon: skill.skill.icon,
+    color: const Color(0xFF18A999),
+    title: 'home.todayPlan.skillTitle'.tr(
+      namedArgs: {'skill': skill.skill.displayName},
+    ),
+    subtitle: 'home.todayPlan.skillSubtitle'.tr(
+      namedArgs: {'level': skill.estimatedLevel},
+    ),
+    actionLabel: 'home.todayPlan.practiceAction'.tr(),
+    metaLabel: 'home.todayPlan.skillScore'.tr(
+      namedArgs: {'score': '${skill.score.round()}'},
+    ),
+    progress: (skill.score / 100).clamp(0.0, 1.0),
+    isCompleted: skill.score >= 80,
+  );
+}
+
+TodayPlanDestination _destinationForSkill(SkillType skill) {
+  switch (skill) {
+    case SkillType.vocabulary:
+      return TodayPlanDestination.vocabularyReview;
+    case SkillType.grammar:
+    case SkillType.writing:
+      return TodayPlanDestination.games;
+    case SkillType.reading:
+      return TodayPlanDestination.news;
+    case SkillType.listening:
+      return TodayPlanDestination.podcast;
+    case SkillType.speaking:
+      return TodayPlanDestination.voice;
+  }
+}
+
+TodayPlanTask _buildChallengeTask(List<DailyChallengeEntity> challenges) {
+  DailyChallengeEntity? challenge;
+  for (final item in challenges) {
+    if (!item.isCompleted) {
+      challenge = item;
+      break;
+    }
+  }
+  challenge ??= challenges.isEmpty ? null : challenges.first;
+
+  if (challenge == null) {
+    return TodayPlanTask(
+      type: TodayPlanTaskType.challenge,
+      destination: TodayPlanDestination.games,
+      icon: Icons.emoji_events_rounded,
+      color: const Color(0xFFFFA319),
+      title: 'home.todayPlan.challengeFallbackTitle'.tr(),
+      subtitle: 'home.todayPlan.challengeFallbackSubtitle'.tr(),
+      actionLabel: 'home.todayPlan.playAction'.tr(),
+      metaLabel: 'home.todayPlan.challengeMeta'.tr(),
+      progress: 0,
+    );
+  }
+
+  return TodayPlanTask(
+    type: TodayPlanTaskType.challenge,
+    destination: _destinationForChallenge(challenge),
+    icon: Icons.emoji_events_rounded,
+    color: const Color(0xFFFFA319),
+    title: challenge.title,
+    subtitle: challenge.description,
+    actionLabel: challenge.isCompleted
+        ? 'home.todayPlan.doneAction'.tr()
+        : 'home.todayPlan.startAction'.tr(),
+    metaLabel: 'home.todayPlan.challengeProgress'.tr(
+      namedArgs: {
+        'current': '${challenge.current}',
+        'target': '${challenge.target}',
+      },
+    ),
+    rewardLabel: '+${challenge.xpReward} XP',
+    progress: challenge.progress,
+    isCompleted: challenge.isCompleted,
+  );
+}
+
+TodayPlanDestination _destinationForChallenge(DailyChallengeEntity challenge) {
+  switch (challenge.category) {
+    case 'vocabulary':
+      return TodayPlanDestination.vocabularyReview;
+    case 'voice':
+      return TodayPlanDestination.voice;
+    default:
+      return TodayPlanDestination.games;
+  }
+}
+
+TodayPlanTask _buildConversationTask() {
+  return TodayPlanTask(
+    type: TodayPlanTaskType.conversation,
+    destination: TodayPlanDestination.lexi,
+    icon: Icons.auto_awesome_rounded,
+    color: const Color(0xFF7C5CFF),
+    title: 'home.todayPlan.lexiTitle'.tr(),
+    subtitle: 'home.todayPlan.lexiSubtitle'.tr(),
+    actionLabel: 'home.todayPlan.chatAction'.tr(),
+    metaLabel: 'home.todayPlan.lexiMeta'.tr(),
+    progress: 0,
+  );
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_navigation.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_navigation.dart
new file mode 100644
index 00000000..cce5886a
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_navigation.dart
@@ -0,0 +1,34 @@
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/features/course/presentation/screens/course_list_screen.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_models.dart';
+import 'package:lexilingo_app/features/voice/presentation/screens/voice_practice_screen.dart';
+
+void openTodayPlanTask(BuildContext context, TodayPlanTask task) {
+  switch (task.destination) {
+    case TodayPlanDestination.vocabularyReview:
+      Navigator.of(context).pushNamed('/vocabulary/review');
+      return;
+    case TodayPlanDestination.courseList:
+      Navigator.of(
+        context,
+      ).push(MaterialPageRoute(builder: (_) => const CourseListScreen()));
+      return;
+    case TodayPlanDestination.games:
+      Navigator.of(context).pushNamed('/games');
+      return;
+    case TodayPlanDestination.lexi:
+      Navigator.of(context).pushNamed('/lexi');
+      return;
+    case TodayPlanDestination.voice:
+      Navigator.of(
+        context,
+      ).push(MaterialPageRoute(builder: (_) => const VoicePracticeScreen()));
+      return;
+    case TodayPlanDestination.news:
+      Navigator.of(context).pushNamed('/news');
+      return;
+    case TodayPlanDestination.podcast:
+      Navigator.of(context).pushNamed('/podcast');
+      return;
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_section.dart b/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_section.dart
new file mode 100644
index 00000000..5e9b0f53
--- /dev/null
+++ b/flutter-app/lib/features/home/presentation/widgets/home_page/today_plan_section.dart
@@ -0,0 +1,355 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_models.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_navigation.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/proficiency_provider.dart';
+import 'package:lexilingo_app/features/progress/presentation/providers/daily_challenges_provider.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/repositories/vocabulary_repository.dart';
+import 'package:lexilingo_app/features/vocabulary/vocabulary_di.dart'
+    as vocab_di;
+
+class TodayPlanSection extends StatefulWidget {
+  const TodayPlanSection({super.key});
+
+  @override
+  State<TodayPlanSection> createState() => _TodayPlanSectionState();
+}
+
+class _TodayPlanSectionState extends State<TodayPlanSection> {
+  int? _dueVocabularyCount;
+  bool _isLoadingVocabulary = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _loadVocabularyStats();
+  }
+
+  Future<void> _loadVocabularyStats() async {
+    final result = await vocab_di
+        .getIt<VocabularyRepository>()
+        .getVocabularyStats();
+
+    if (!mounted) return;
+
+    setState(() {
+      _dueVocabularyCount = result.fold(
+        (_) => null,
+        (stats) => stats['due_for_review'] as int? ?? 0,
+      );
+      _isLoadingVocabulary = false;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final colorScheme = Theme.of(context).colorScheme;
+    final accent = AppColorRoles.primary(isDark);
+
+    return Consumer3<
+      HomeProvider,
+      DailyChallengesProvider,
+      ProficiencyProvider
+    >(
+      builder: (context, home, challenges, proficiency, _) {
+        final snapshot = buildTodayPlanSnapshot(
+          enrolledCourses: home.enrolledCourses,
+          challenges: challenges.challenges,
+          weakestSkills: proficiency.weakestSkills,
+          dueVocabularyCount: _isLoadingVocabulary ? null : _dueVocabularyCount,
+        );
+        final visibleTasks = snapshot.tasks.take(3).toList();
+
+        return Padding(
+          padding: const EdgeInsets.fromLTRB(16, 12, 16, 0),
+          child: Material(
+            color: Colors.transparent,
+            child: InkWell(
+              borderRadius: BorderRadius.circular(20),
+              onTap: () => Navigator.of(context).pushNamed('/today-plan'),
+              child: Container(
+                padding: const EdgeInsets.all(16),
+                decoration: BoxDecoration(
+                  color: isDark
+                      ? colorScheme.surfaceContainerHighest
+                      : Colors.white,
+                  borderRadius: BorderRadius.circular(20),
+                  border: Border.all(
+                    color: isDark
+                        ? Colors.white.withValues(alpha: 0.10)
+                        : AppColors.grey200,
+                  ),
+                  boxShadow: [
+                    BoxShadow(
+                      color: Colors.black.withValues(
+                        alpha: isDark ? 0.22 : 0.06,
+                      ),
+                      blurRadius: 16,
+                      offset: const Offset(0, 8),
+                    ),
+                  ],
+                ),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Container(
+                          width: 42,
+                          height: 42,
+                          decoration: BoxDecoration(
+                            color: accent.withValues(alpha: 0.14),
+                            borderRadius: BorderRadius.circular(14),
+                          ),
+                          child: Icon(
+                            Icons.route_rounded,
+                            color: accent,
+                            size: 24,
+                          ),
+                        ),
+                        const SizedBox(width: 12),
+                        Expanded(
+                          child: Column(
+                            crossAxisAlignment: CrossAxisAlignment.start,
+                            children: [
+                              Text(
+                                'home.todayPlan.title'.tr(),
+                                style: Theme.of(context).textTheme.titleLarge
+                                    ?.copyWith(fontWeight: FontWeight.w800),
+                              ),
+                              const SizedBox(height: 2),
+                              Text(
+                                'home.todayPlan.subtitle'.tr(),
+                                maxLines: 1,
+                                overflow: TextOverflow.ellipsis,
+                                style: Theme.of(context).textTheme.bodySmall
+                                    ?.copyWith(
+                                      color: AppColorRoles.textMuted(isDark),
+                                    ),
+                              ),
+                            ],
+                          ),
+                        ),
+                        _PlanProgressPill(snapshot: snapshot, color: accent),
+                      ],
+                    ),
+                    const SizedBox(height: 14),
+                    ClipRRect(
+                      borderRadius: BorderRadius.circular(999),
+                      child: LinearProgressIndicator(
+                        minHeight: 7,
+                        value: snapshot.progress,
+                        backgroundColor: accent.withValues(alpha: 0.14),
+                        valueColor: AlwaysStoppedAnimation<Color>(accent),
+                      ),
+                    ),
+                    const SizedBox(height: 12),
+                    ...visibleTasks.map(
+                      (task) => Padding(
+                        padding: const EdgeInsets.only(bottom: 10),
+                        child: _TodayPlanTaskTile(
+                          task: task,
+                          dense: true,
+                          onTap: () => openTodayPlanTask(context, task),
+                        ),
+                      ),
+                    ),
+                    Row(
+                      children: [
+                        Expanded(
+                          child: Text(
+                            'home.todayPlan.footer'.tr(),
+                            style: Theme.of(context).textTheme.bodySmall
+                                ?.copyWith(
+                                  color: AppColorRoles.textMuted(isDark),
+                                ),
+                          ),
+                        ),
+                        TextButton(
+                          onPressed: () =>
+                              Navigator.of(context).pushNamed('/today-plan'),
+                          child: Text('home.todayPlan.viewAll'.tr()),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ),
+        );
+      },
+    );
+  }
+}
+
+class _PlanProgressPill extends StatelessWidget {
+  const _PlanProgressPill({required this.snapshot, required this.color});
+
+  final TodayPlanSnapshot snapshot;
+  final Color color;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: 0.12),
+        borderRadius: BorderRadius.circular(999),
+      ),
+      child: Text(
+        '${snapshot.completedCount}/${snapshot.totalCount}',
+        style: TextStyle(
+          color: color,
+          fontWeight: FontWeight.w800,
+          fontSize: 12,
+        ),
+      ),
+    );
+  }
+}
+
+class TodayPlanTaskTile extends StatelessWidget {
+  const TodayPlanTaskTile({super.key, required this.task, required this.onTap});
+
+  final TodayPlanTask task;
+  final VoidCallback onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    return _TodayPlanTaskTile(task: task, onTap: onTap);
+  }
+}
+
+class _TodayPlanTaskTile extends StatelessWidget {
+  const _TodayPlanTaskTile({
+    required this.task,
+    required this.onTap,
+    this.dense = false,
+  });
+
+  final TodayPlanTask task;
+  final VoidCallback onTap;
+  final bool dense;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final colorScheme = Theme.of(context).colorScheme;
+    final muted = AppColorRoles.textMuted(isDark);
+
+    return Material(
+      color: Colors.transparent,
+      child: InkWell(
+        borderRadius: BorderRadius.circular(16),
+        onTap: onTap,
+        child: Container(
+          padding: EdgeInsets.all(dense ? 10 : 14),
+          decoration: BoxDecoration(
+            color: task.isCompleted
+                ? task.color.withValues(alpha: 0.10)
+                : colorScheme.surface.withValues(alpha: isDark ? 0.36 : 0.92),
+            borderRadius: BorderRadius.circular(16),
+            border: Border.all(
+              color: task.isCompleted
+                  ? task.color.withValues(alpha: 0.32)
+                  : colorScheme.outlineVariant.withValues(alpha: 0.55),
+            ),
+          ),
+          child: Row(
+            children: [
+              Container(
+                width: dense ? 40 : 48,
+                height: dense ? 40 : 48,
+                decoration: BoxDecoration(
+                  color: task.color.withValues(alpha: 0.14),
+                  borderRadius: BorderRadius.circular(14),
+                ),
+                child: Icon(
+                  task.icon,
+                  color: task.color,
+                  size: dense ? 21 : 25,
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      task.title,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: Theme.of(context).textTheme.titleSmall?.copyWith(
+                        fontWeight: FontWeight.w800,
+                      ),
+                    ),
+                    const SizedBox(height: 3),
+                    Text(
+                      task.subtitle,
+                      maxLines: dense ? 1 : 2,
+                      overflow: TextOverflow.ellipsis,
+                      style: Theme.of(
+                        context,
+                      ).textTheme.bodySmall?.copyWith(color: muted),
+                    ),
+                    if (!dense) ...[
+                      const SizedBox(height: 8),
+                      ClipRRect(
+                        borderRadius: BorderRadius.circular(999),
+                        child: LinearProgressIndicator(
+                          minHeight: 5,
+                          value: task.progress,
+                          backgroundColor: task.color.withValues(alpha: 0.12),
+                          valueColor: AlwaysStoppedAnimation<Color>(task.color),
+                        ),
+                      ),
+                    ],
+                  ],
+                ),
+              ),
+              const SizedBox(width: 8),
+              Column(
+                crossAxisAlignment: CrossAxisAlignment.end,
+                children: [
+                  if (task.rewardLabel != null)
+                    Text(
+                      task.rewardLabel!,
+                      style: TextStyle(
+                        color: task.color,
+                        fontSize: 11,
+                        fontWeight: FontWeight.w800,
+                      ),
+                    ),
+                  if (task.metaLabel != null)
+                    Text(
+                      task.metaLabel!,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: TextStyle(
+                        color: muted,
+                        fontSize: 11,
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                  const SizedBox(height: 5),
+                  Icon(
+                    task.isCompleted
+                        ? Icons.check_circle_rounded
+                        : Icons.arrow_forward_ios_rounded,
+                    color: task.isCompleted ? task.color : muted,
+                    size: task.isCompleted ? 18 : 14,
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/home/presentation/widgets/home_ui_components.dart b/flutter-app/lib/features/home/presentation/widgets/home_ui_components.dart
index 0f7da098..8026f416 100644
--- a/flutter-app/lib/features/home/presentation/widgets/home_ui_components.dart
+++ b/flutter-app/lib/features/home/presentation/widgets/home_ui_components.dart
@@ -21,19 +21,19 @@ String getTimeBasedGreeting() {
   }
 }
 
-/// Get game icon based on time of day
-GameIcon getTimeBasedGameIcon() {
+/// Get icon based on time of day
+IconData getTimeBasedIcon() {
   final hour = DateTime.now().hour;
   if (hour < 5) {
-    return GameIcon.moonNight;
+    return Icons.nightlight_round;
   } else if (hour < 12) {
-    return GameIcon.sunMorning;
+    return Icons.wb_sunny_rounded;
   } else if (hour < 18) {
-    return GameIcon.sunsetAfternoon; // Sunset/afternoon
+    return Icons.wb_twilight_rounded;
   } else if (hour < 22) {
-    return GameIcon.moonNight; // Evening
+    return Icons.nightlight_round;
   } else {
-    return GameIcon.moonNight;
+    return Icons.nightlight_round;
   }
 }
 
@@ -76,7 +76,7 @@ class PersonalizedGreetingHeader extends StatelessWidget {
   Widget build(BuildContext context) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
     final greeting = getTimeBasedGreeting();
-    final timeIcon = getTimeBasedGameIcon();
+    final timeIcon = getTimeBasedIcon();
     final iconColor = getTimeBasedIconColor(isDark: isDark);
     final accent = AppColorRoles.primary(isDark);
 
@@ -130,7 +130,7 @@ class PersonalizedGreetingHeader extends StatelessWidget {
                       ),
                     ),
                     const SizedBox(width: 6),
-                    AppGameIcon(timeIcon, size: 16, fallbackColor: iconColor),
+                    Icon(timeIcon, size: 16, color: iconColor),
                   ],
                 ),
                 const SizedBox(height: 2),
@@ -309,10 +309,10 @@ class _AnimatedXPCounterState extends State<_AnimatedXPCounter>
                 children: [
                   Transform.scale(
                     scale: _sparkleAnimation.value,
-                    child: const AppGameIcon(
-                      GameIcon.star,
+                    child: const Icon(
+                      Icons.star_rounded,
                       size: 16,
-                      fallbackColor: AppColors.orange,
+                      color: AppColors.orange,
                     ),
                   ),
                   const SizedBox(width: 4),
@@ -424,10 +424,10 @@ class _NotificationBellState extends State<_NotificationBell>
               child: Stack(
                 alignment: Alignment.center,
                 children: [
-                  AppGameIcon(
-                    GameIcon.notificationBell,
+                  Icon(
+                    Icons.notifications_rounded,
                     size: 22,
-                    fallbackColor: isDark ? Colors.white : Colors.grey[700],
+                    color: isDark ? Colors.white : Colors.grey[700],
                   ),
                   if (widget.count > 0)
                     Positioned(
@@ -619,10 +619,10 @@ class _AnimatedStreakCardState extends State<AnimatedStreakCard>
                   child: Row(
                     mainAxisSize: MainAxisSize.min,
                     children: [
-                      AppGameIcon(
-                        GameIcon.calendar,
+                      Icon(
+                        Icons.calendar_month_rounded,
                         size: 14,
-                        fallbackColor: isDark
+                        color: isDark
                             ? AppColors.primaryDarkModeSoft
                             : AppColors.teal,
                       ),
@@ -837,9 +837,7 @@ class _AnimatedStreakCardState extends State<AnimatedStreakCard>
                   boxShadow: isActive
                       ? [
                           BoxShadow(
-                            color: AppColors.deepOrange.withValues(
-                              alpha: 0.4,
-                            ),
+                            color: AppColors.deepOrange.withValues(alpha: 0.4),
                             blurRadius: 0,
                             offset: const Offset(0, 2),
                           ),
diff --git a/flutter-app/lib/features/level/data/datasources/proficiency_data_source.dart b/flutter-app/lib/features/level/data/datasources/proficiency_data_source.dart
index 2e06b626..20f04f9c 100644
--- a/flutter-app/lib/features/level/data/datasources/proficiency_data_source.dart
+++ b/flutter-app/lib/features/level/data/datasources/proficiency_data_source.dart
@@ -2,6 +2,20 @@ import '../../../../core/network/api_client.dart';
 import '../../../../core/services/local_cache_service.dart';
 import '../../domain/entities/proficiency_entity.dart';
 
+List<Map<String, int>> buildPlacementAnswerPayload(Map<String, int> answers) {
+  final payload = <Map<String, int>>[];
+
+  for (final entry in answers.entries) {
+    final questionId = int.tryParse(entry.key);
+    if (questionId == null) continue;
+
+    payload.add({'question_id': questionId, 'selected_option': entry.value});
+  }
+
+  payload.sort((a, b) => a['question_id']!.compareTo(b['question_id']!));
+  return payload;
+}
+
 /// Data source for proficiency assessment API calls
 class ProficiencyDataSource {
   final ApiClient _apiClient;
@@ -67,7 +81,7 @@ class ProficiencyDataSource {
   }) async {
     return await _apiClient.post(
       '/proficiency/placement-test/submit',
-      body: {'answers': answers, 'time_taken_seconds': timeTakenSeconds},
+      body: {'answers': buildPlacementAnswerPayload(answers)},
     );
   }
 }
diff --git a/flutter-app/lib/features/level/di/level_di.dart b/flutter-app/lib/features/level/di/level_di.dart
index d070881c..3734a3dc 100644
--- a/flutter-app/lib/features/level/di/level_di.dart
+++ b/flutter-app/lib/features/level/di/level_di.dart
@@ -2,12 +2,15 @@ import 'package:lexilingo_app/core/di/service_locator.dart';
 import 'package:lexilingo_app/core/network/api_client.dart';
 import 'package:lexilingo_app/features/level/data/datasources/proficiency_data_source.dart';
 import 'package:lexilingo_app/features/level/presentation/providers/level_provider.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/placement_test_provider.dart';
 import 'package:lexilingo_app/features/level/presentation/providers/proficiency_provider.dart';
 
 /// Registers all level-related dependencies
 void registerLevelModule() {
   // Provider - Factory for fresh instances
-  sl.registerFactory<LevelProvider>(() => LevelProvider(apiClient: sl<ApiClient>()));
+  sl.registerFactory<LevelProvider>(
+    () => LevelProvider(apiClient: sl<ApiClient>()),
+  );
 
   // Proficiency data source (singleton — stateless HTTP wrapper)
   sl.registerLazySingleton<ProficiencyDataSource>(
@@ -18,4 +21,8 @@ void registerLevelModule() {
   sl.registerFactory<ProficiencyProvider>(
     () => ProficiencyProvider(dataSource: sl<ProficiencyDataSource>()),
   );
+
+  sl.registerFactory<PlacementTestProvider>(
+    () => PlacementTestProvider(dataSource: sl<ProficiencyDataSource>()),
+  );
 }
diff --git a/flutter-app/lib/features/level/presentation/pages/placement_test_page.dart b/flutter-app/lib/features/level/presentation/pages/placement_test_page.dart
new file mode 100644
index 00000000..20a44397
--- /dev/null
+++ b/flutter-app/lib/features/level/presentation/pages/placement_test_page.dart
@@ -0,0 +1,760 @@
+import 'dart:async';
+
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/cefr_badge.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/placement_test_provider.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/proficiency_provider.dart';
+import 'package:provider/provider.dart';
+
+class PlacementTestPage extends StatefulWidget {
+  const PlacementTestPage({super.key});
+
+  @override
+  State<PlacementTestPage> createState() => _PlacementTestPageState();
+}
+
+class _PlacementTestPageState extends State<PlacementTestPage> {
+  final Map<String, int> _answers = {};
+  Timer? _timer;
+  int _currentIndex = 0;
+  int _elapsedSeconds = 0;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _loadTest(reset: true);
+    });
+  }
+
+  @override
+  void dispose() {
+    _timer?.cancel();
+    super.dispose();
+  }
+
+  Future<void> _loadTest({bool reset = false}) async {
+    if (reset) {
+      _timer?.cancel();
+      _answers.clear();
+      _currentIndex = 0;
+      _elapsedSeconds = 0;
+      context.read<PlacementTestProvider>().reset();
+      if (mounted) setState(() {});
+    }
+
+    await context.read<PlacementTestProvider>().loadTest();
+    if (!mounted) return;
+
+    if (context.read<PlacementTestProvider>().questions.isNotEmpty) {
+      _startTimer();
+    }
+  }
+
+  void _startTimer() {
+    _timer?.cancel();
+    _timer = Timer.periodic(const Duration(seconds: 1), (_) {
+      if (!mounted) return;
+      setState(() => _elapsedSeconds += 1);
+    });
+  }
+
+  String _formatElapsedTime() {
+    final minutes = (_elapsedSeconds ~/ 60).toString().padLeft(2, '0');
+    final seconds = (_elapsedSeconds % 60).toString().padLeft(2, '0');
+    return '$minutes:$seconds';
+  }
+
+  void _selectAnswer(String questionId, int optionIndex) {
+    setState(() {
+      _answers[questionId] = optionIndex;
+    });
+  }
+
+  void _goToQuestion(int index, int total) {
+    if (index < 0 || index >= total) return;
+    setState(() => _currentIndex = index);
+  }
+
+  Future<void> _submit() async {
+    final provider = context.read<PlacementTestProvider>();
+    final total = provider.questions.length;
+    if (_answers.length < total) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text('assessment.answerAllQuestions'.tr())),
+      );
+      return;
+    }
+
+    final submitted = await provider.submitTest(_answers, _elapsedSeconds);
+    if (!mounted) return;
+
+    if (submitted) {
+      _timer?.cancel();
+      await context.read<ProficiencyProvider>().loadProfile();
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+
+    return Scaffold(
+      backgroundColor: isDark
+          ? AppColors.backgroundDark
+          : AppColors.backgroundLight,
+      appBar: AppBar(
+        title: Text('assessment.placementTest'.tr()),
+        actions: [
+          Padding(
+            padding: const EdgeInsetsDirectional.only(end: 16),
+            child: Center(
+              child: _MetaChip(
+                icon: Icons.timer_rounded,
+                label: _formatElapsedTime(),
+                color: accent,
+              ),
+            ),
+          ),
+        ],
+      ),
+      body: SafeArea(
+        child: Consumer<PlacementTestProvider>(
+          builder: (context, provider, _) {
+            if (provider.isLoading && provider.questions.isEmpty) {
+              return const Center(child: CircularProgressIndicator());
+            }
+
+            if (provider.errorMessage != null && provider.questions.isEmpty) {
+              return _ErrorState(
+                message: provider.errorMessage!,
+                onRetry: () => _loadTest(reset: true),
+              );
+            }
+
+            if (provider.result != null) {
+              return _ResultState(
+                result: provider.result!,
+                onRetake: () => _loadTest(reset: true),
+              );
+            }
+
+            if (provider.questions.isEmpty) {
+              return _EmptyState(onRetry: () => _loadTest(reset: true));
+            }
+
+            return _QuestionState(
+              questions: provider.questions,
+              currentIndex: _currentIndex,
+              answers: _answers,
+              isSubmitting: provider.isLoading,
+              elapsedLabel: _formatElapsedTime(),
+              onSelectAnswer: _selectAnswer,
+              onPrevious: () =>
+                  _goToQuestion(_currentIndex - 1, provider.questions.length),
+              onNext: () =>
+                  _goToQuestion(_currentIndex + 1, provider.questions.length),
+              onSubmit: _submit,
+            );
+          },
+        ),
+      ),
+    );
+  }
+}
+
+class _QuestionState extends StatelessWidget {
+  const _QuestionState({
+    required this.questions,
+    required this.currentIndex,
+    required this.answers,
+    required this.isSubmitting,
+    required this.elapsedLabel,
+    required this.onSelectAnswer,
+    required this.onPrevious,
+    required this.onNext,
+    required this.onSubmit,
+  });
+
+  final List<Map<String, dynamic>> questions;
+  final int currentIndex;
+  final Map<String, int> answers;
+  final bool isSubmitting;
+  final String elapsedLabel;
+  final void Function(String questionId, int optionIndex) onSelectAnswer;
+  final VoidCallback onPrevious;
+  final VoidCallback onNext;
+  final VoidCallback onSubmit;
+
+  @override
+  Widget build(BuildContext context) {
+    final question = questions[currentIndex];
+    final questionId = '${question['id'] ?? currentIndex + 1}';
+    final options = List<String>.from(question['options'] ?? const <String>[]);
+    final selectedOption = answers[questionId];
+    final isLast = currentIndex == questions.length - 1;
+    final progress = (currentIndex + 1) / questions.length;
+    final answeredCount = answers.length;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+    final surface = isDark ? AppColors.surfaceDarkMuted : Colors.white;
+    final border = isDark ? AppColors.borderDarkSoft : AppColors.slate200;
+
+    return ListView(
+      padding: const EdgeInsets.fromLTRB(16, 12, 16, 24),
+      children: [
+        Row(
+          children: [
+            Expanded(
+              child: Text(
+                'assessment.questionCounter'.tr(
+                  namedArgs: {
+                    'current': '${currentIndex + 1}',
+                    'total': '${questions.length}',
+                  },
+                ),
+                style: Theme.of(
+                  context,
+                ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w700),
+              ),
+            ),
+            _MetaChip(
+              icon: Icons.fact_check_rounded,
+              label: 'assessment.answeredCount'.tr(
+                namedArgs: {
+                  'answered': '$answeredCount',
+                  'total': '${questions.length}',
+                },
+              ),
+              color: accent,
+            ),
+          ],
+        ),
+        const SizedBox(height: 12),
+        ClipRRect(
+          borderRadius: BorderRadius.circular(999),
+          child: LinearProgressIndicator(
+            value: progress,
+            minHeight: 8,
+            backgroundColor: isDark
+                ? Colors.white.withValues(alpha: 0.08)
+                : AppColors.grey200,
+            valueColor: AlwaysStoppedAnimation<Color>(accent),
+          ),
+        ),
+        const SizedBox(height: 18),
+        Container(
+          padding: const EdgeInsets.all(18),
+          decoration: BoxDecoration(
+            color: surface,
+            borderRadius: BorderRadius.circular(16),
+            border: Border.all(color: border),
+          ),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Wrap(
+                spacing: 8,
+                runSpacing: 8,
+                children: [
+                  CefrBadge(
+                    level: '${question['level'] ?? 'A1'}',
+                    size: CefrBadgeSize.large,
+                  ),
+                  _TextChip(
+                    label: '${question['skill'] ?? 'general'}',
+                    icon: Icons.psychology_alt_rounded,
+                  ),
+                  _TextChip(
+                    label: 'assessment.points'.tr(
+                      namedArgs: {'points': '${question['points'] ?? 0}'},
+                    ),
+                    icon: Icons.stars_rounded,
+                  ),
+                  _TextChip(label: elapsedLabel, icon: Icons.timer_rounded),
+                ],
+              ),
+              const SizedBox(height: 18),
+              Text(
+                '${question['question'] ?? ''}',
+                style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                  fontWeight: FontWeight.w800,
+                  height: 1.25,
+                ),
+              ),
+              const SizedBox(height: 18),
+              for (var i = 0; i < options.length; i++) ...[
+                _AnswerOption(
+                  index: i,
+                  text: options[i],
+                  selected: selectedOption == i,
+                  onTap: () => onSelectAnswer(questionId, i),
+                ),
+                if (i != options.length - 1) const SizedBox(height: 10),
+              ],
+            ],
+          ),
+        ),
+        const SizedBox(height: 18),
+        Row(
+          children: [
+            Expanded(
+              child: OutlinedButton.icon(
+                onPressed: currentIndex == 0 ? null : onPrevious,
+                icon: const Icon(Icons.arrow_back_rounded),
+                label: Text('assessment.previous'.tr()),
+              ),
+            ),
+            const SizedBox(width: 12),
+            Expanded(
+              child: ElevatedButton.icon(
+                onPressed: isSubmitting
+                    ? null
+                    : isLast
+                    ? onSubmit
+                    : onNext,
+                icon: isSubmitting
+                    ? const SizedBox(
+                        width: 16,
+                        height: 16,
+                        child: CircularProgressIndicator(strokeWidth: 2),
+                      )
+                    : Icon(
+                        isLast
+                            ? Icons.check_circle_rounded
+                            : Icons.arrow_forward_rounded,
+                      ),
+                label: Text(
+                  isLast
+                      ? 'assessment.submitTest'.tr()
+                      : 'assessment.next'.tr(),
+                ),
+                style: ElevatedButton.styleFrom(
+                  backgroundColor: accent,
+                  foregroundColor: Colors.white,
+                ),
+              ),
+            ),
+          ],
+        ),
+      ],
+    );
+  }
+}
+
+class _AnswerOption extends StatelessWidget {
+  const _AnswerOption({
+    required this.index,
+    required this.text,
+    required this.selected,
+    required this.onTap,
+  });
+
+  final int index;
+  final String text;
+  final bool selected;
+  final VoidCallback onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+    final border = selected
+        ? accent
+        : isDark
+        ? AppColors.borderDarkSoft
+        : AppColors.slate200;
+    final background = selected
+        ? accent.withValues(alpha: isDark ? 0.2 : 0.1)
+        : isDark
+        ? AppColors.surfaceDarkInput
+        : AppColors.grey50;
+
+    return Material(
+      color: background,
+      borderRadius: BorderRadius.circular(12),
+      child: InkWell(
+        onTap: onTap,
+        borderRadius: BorderRadius.circular(12),
+        child: Container(
+          width: double.infinity,
+          padding: const EdgeInsets.all(14),
+          decoration: BoxDecoration(
+            borderRadius: BorderRadius.circular(12),
+            border: Border.all(color: border, width: selected ? 1.5 : 1),
+          ),
+          child: Row(
+            children: [
+              Container(
+                width: 28,
+                height: 28,
+                alignment: Alignment.center,
+                decoration: BoxDecoration(
+                  shape: BoxShape.circle,
+                  color: selected ? accent : Colors.transparent,
+                  border: Border.all(color: selected ? accent : border),
+                ),
+                child: Text(
+                  String.fromCharCode(65 + index),
+                  style: TextStyle(
+                    color: selected
+                        ? Colors.white
+                        : AppColorRoles.textPrimary(isDark),
+                    fontWeight: FontWeight.w800,
+                  ),
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Text(
+                  text,
+                  style: Theme.of(context).textTheme.bodyLarge?.copyWith(
+                    fontWeight: selected ? FontWeight.w700 : FontWeight.w500,
+                    height: 1.25,
+                  ),
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _ResultState extends StatelessWidget {
+  const _ResultState({required this.result, required this.onRetake});
+
+  final Map<String, dynamic> result;
+  final VoidCallback onRetake;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+    final level = '${result['assessed_level'] ?? 'A1'}';
+    final score = result['score_percentage'] ?? 0;
+    final correct = result['correct_count'] ?? 0;
+    final total = result['total_questions'] ?? 0;
+
+    return ListView(
+      padding: const EdgeInsets.fromLTRB(16, 18, 16, 24),
+      children: [
+        Container(
+          padding: const EdgeInsets.all(22),
+          decoration: BoxDecoration(
+            color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+            borderRadius: BorderRadius.circular(18),
+            border: Border.all(
+              color: isDark ? AppColors.borderDarkSoft : AppColors.slate200,
+            ),
+          ),
+          child: Column(
+            children: [
+              Container(
+                width: 68,
+                height: 68,
+                decoration: BoxDecoration(
+                  shape: BoxShape.circle,
+                  color: accent.withValues(alpha: 0.14),
+                ),
+                child: Icon(
+                  Icons.emoji_events_rounded,
+                  color: accent,
+                  size: 34,
+                ),
+              ),
+              const SizedBox(height: 16),
+              Text(
+                'assessment.testCompleted'.tr(),
+                textAlign: TextAlign.center,
+                style: Theme.of(context).textTheme.headlineSmall?.copyWith(
+                  fontWeight: FontWeight.w900,
+                ),
+              ),
+              const SizedBox(height: 8),
+              Text(
+                'assessment.resultSubtitle'.tr(),
+                textAlign: TextAlign.center,
+                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                  color: AppColorRoles.textSecondary(isDark),
+                  height: 1.35,
+                ),
+              ),
+              const SizedBox(height: 20),
+              CefrBadge(
+                level: level,
+                size: CefrBadgeSize.large,
+                outlined: true,
+              ),
+              const SizedBox(height: 10),
+              Text(
+                'assessment.yourLevelIs'.tr(namedArgs: {'level': level}),
+                style: Theme.of(
+                  context,
+                ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.w900),
+              ),
+              const SizedBox(height: 20),
+              Row(
+                children: [
+                  Expanded(
+                    child: _ResultMetric(
+                      label: 'assessment.score'.tr(),
+                      value: '$score%',
+                    ),
+                  ),
+                  const SizedBox(width: 10),
+                  Expanded(
+                    child: _ResultMetric(
+                      label: 'assessment.correct'.tr(),
+                      value: '$correct/$total',
+                    ),
+                  ),
+                ],
+              ),
+              if (result['rank_name'] != null) ...[
+                const SizedBox(height: 10),
+                _ResultMetric(
+                  label: 'assessment.rank'.tr(),
+                  value: '${result['rank_name']}',
+                ),
+              ],
+              const SizedBox(height: 22),
+              Row(
+                children: [
+                  Expanded(
+                    child: OutlinedButton.icon(
+                      onPressed: onRetake,
+                      icon: const Icon(Icons.replay_rounded),
+                      label: Text('assessment.retakeTest'.tr()),
+                    ),
+                  ),
+                  const SizedBox(width: 12),
+                  Expanded(
+                    child: ElevatedButton.icon(
+                      onPressed: () => Navigator.of(context).pop(),
+                      icon: const Icon(Icons.check_rounded),
+                      label: Text('common.done'.tr()),
+                      style: ElevatedButton.styleFrom(
+                        backgroundColor: accent,
+                        foregroundColor: Colors.white,
+                      ),
+                    ),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _ResultMetric extends StatelessWidget {
+  const _ResultMetric({required this.label, required this.value});
+
+  final String label;
+  final String value;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 14),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkInput : AppColors.grey50,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        children: [
+          Text(
+            value,
+            textAlign: TextAlign.center,
+            style: Theme.of(
+              context,
+            ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w900),
+          ),
+          const SizedBox(height: 4),
+          Text(
+            label,
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: AppColorRoles.textSecondary(isDark),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _ErrorState extends StatelessWidget {
+  const _ErrorState({required this.message, required this.onRetry});
+
+  final String message;
+  final VoidCallback onRetry;
+
+  @override
+  Widget build(BuildContext context) {
+    return _CenteredState(
+      icon: Icons.error_outline_rounded,
+      title: 'assessment.loadFailed'.tr(),
+      message: message,
+      actionLabel: 'common.retry'.tr(),
+      onAction: onRetry,
+    );
+  }
+}
+
+class _EmptyState extends StatelessWidget {
+  const _EmptyState({required this.onRetry});
+
+  final VoidCallback onRetry;
+
+  @override
+  Widget build(BuildContext context) {
+    return _CenteredState(
+      icon: Icons.quiz_rounded,
+      title: 'assessment.noQuestions'.tr(),
+      message: 'assessment.noQuestionsSubtitle'.tr(),
+      actionLabel: 'common.retry'.tr(),
+      onAction: onRetry,
+    );
+  }
+}
+
+class _CenteredState extends StatelessWidget {
+  const _CenteredState({
+    required this.icon,
+    required this.title,
+    required this.message,
+    required this.actionLabel,
+    required this.onAction,
+  });
+
+  final IconData icon;
+  final String title;
+  final String message;
+  final String actionLabel;
+  final VoidCallback onAction;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(24),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(icon, size: 44, color: accent),
+            const SizedBox(height: 14),
+            Text(
+              title,
+              textAlign: TextAlign.center,
+              style: Theme.of(
+                context,
+              ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.w800),
+            ),
+            const SizedBox(height: 8),
+            Text(
+              message,
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: AppColorRoles.textSecondary(isDark),
+                height: 1.35,
+              ),
+            ),
+            const SizedBox(height: 18),
+            ElevatedButton.icon(
+              onPressed: onAction,
+              icon: const Icon(Icons.refresh_rounded),
+              label: Text(actionLabel),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _MetaChip extends StatelessWidget {
+  const _MetaChip({
+    required this.icon,
+    required this.label,
+    required this.color,
+  });
+
+  final IconData icon;
+  final String label;
+  final Color color;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: isDark ? 0.18 : 0.1),
+        borderRadius: BorderRadius.circular(999),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(icon, size: 15, color: color),
+          const SizedBox(width: 6),
+          Text(
+            label,
+            style: TextStyle(
+              color: color,
+              fontWeight: FontWeight.w800,
+              fontSize: 12,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _TextChip extends StatelessWidget {
+  const _TextChip({required this.label, required this.icon});
+
+  final String label;
+  final IconData icon;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 9, vertical: 5),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkInput : AppColors.grey100,
+        borderRadius: BorderRadius.circular(8),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(icon, size: 14, color: AppColorRoles.textSecondary(isDark)),
+          const SizedBox(width: 5),
+          Text(
+            label,
+            style: Theme.of(context).textTheme.labelSmall?.copyWith(
+              fontWeight: FontWeight.w700,
+              color: AppColorRoles.textSecondary(isDark),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/level/presentation/widgets/proficiency_card.dart b/flutter-app/lib/features/level/presentation/widgets/proficiency_card.dart
index 94ecbc8d..08b0db96 100644
--- a/flutter-app/lib/features/level/presentation/widgets/proficiency_card.dart
+++ b/flutter-app/lib/features/level/presentation/widgets/proficiency_card.dart
@@ -160,12 +160,17 @@ class ProficiencyCard extends StatelessWidget {
               // Action buttons
               Row(
                 children: [
-                  // Share button
+                  // Placement test button
                   Expanded(
-                    flex: 2,
+                    flex: 3,
                     child: GestureDetector(
-                      onTap: () {
-                        // TODO: Implement share proficiency
+                      onTap: () async {
+                        await Navigator.pushNamed(context, '/placement-test');
+                        if (context.mounted) {
+                          await context
+                              .read<ProficiencyProvider>()
+                              .loadProfile();
+                        }
                       },
                       child: Container(
                         padding: const EdgeInsets.symmetric(vertical: 12),
@@ -184,19 +189,23 @@ class ProficiencyCard extends StatelessWidget {
                           mainAxisAlignment: MainAxisAlignment.center,
                           children: [
                             Icon(
-                              Icons.share_rounded,
+                              Icons.quiz_rounded,
                               size: 16,
                               color: isDark ? Colors.white : AppColors.textDark,
                             ),
                             const SizedBox(width: 6),
-                            Text(
-                              'social.share'.tr(),
-                              style: TextStyle(
-                                fontWeight: FontWeight.w600,
-                                fontSize: 14,
-                                color: isDark
-                                    ? Colors.white
-                                    : AppColors.textDark,
+                            Flexible(
+                              child: Text(
+                                'assessment.placementTest'.tr(),
+                                maxLines: 1,
+                                overflow: TextOverflow.ellipsis,
+                                style: TextStyle(
+                                  fontWeight: FontWeight.w600,
+                                  fontSize: 14,
+                                  color: isDark
+                                      ? Colors.white
+                                      : AppColors.textDark,
+                                ),
                               ),
                             ),
                           ],
@@ -207,7 +216,7 @@ class ProficiencyCard extends StatelessWidget {
                   const SizedBox(width: 12),
                   // Start Lessons button
                   Expanded(
-                    flex: 3,
+                    flex: 2,
                     child: GestureDetector(
                       onTap: () {
                         Navigator.pushReplacement(
diff --git a/flutter-app/lib/features/lexi_chat/data/datasources/lexi_chat_data_source.dart b/flutter-app/lib/features/lexi_chat/data/datasources/lexi_chat_data_source.dart
index c090951b..48bd5399 100644
--- a/flutter-app/lib/features/lexi_chat/data/datasources/lexi_chat_data_source.dart
+++ b/flutter-app/lib/features/lexi_chat/data/datasources/lexi_chat_data_source.dart
@@ -48,6 +48,17 @@ class LexiChatDataSource {
         msg.contains('401');
   }
 
+  bool _isForbiddenError(Object error) {
+    final msg = error.toString().toLowerCase();
+    return msg.contains('status 403') ||
+        msg.contains('403') ||
+        msg.contains('forbidden');
+  }
+
+  bool _isSessionAccessError(Object error) {
+    return _isSessionNotFoundError(error) || _isForbiddenError(error);
+  }
+
   String _normalizeMarkdownBoldMarkers(String text) {
     if (!text.contains('**')) return text;
 
@@ -191,6 +202,7 @@ class LexiChatDataSource {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
     String? idempotencyKey,
   }) async {
@@ -202,6 +214,7 @@ class LexiChatDataSource {
       if (audioBase64 != null) 'audio_base64': audioBase64,
       'enable_tts': enableTts,
       'learner_level': learnerLevel,
+      'native_language': nativeLanguage,
       if (storyContext != null) 'story_context': storyContext,
     };
 
@@ -288,6 +301,7 @@ class LexiChatDataSource {
         );
       }).toList();
     } catch (e) {
+      if (_isSessionAccessError(e)) rethrow;
       logWarn(_tag, 'getMessages failed, return empty history: $e');
       return [];
     }
@@ -346,17 +360,9 @@ class LexiChatDataSource {
         returned: (pagination['returned'] as num?)?.toInt() ?? messages.length,
       );
     } catch (e) {
-      if (_isSessionNotFoundError(e)) {
-        logWarn(
-          _tag,
-          'getMessagesPaged session not found, return empty page: $e',
-        );
-        return const LexiMessagesPage(
-          messages: [],
-          hasMore: false,
-          nextCursor: null,
-          returned: 0,
-        );
+      if (_isSessionAccessError(e)) {
+        logWarn(_tag, 'getMessagesPaged session unavailable: $e');
+        rethrow;
       }
       logWarn(_tag, 'getMessagesPaged fallback to full history: $e');
       final all = await getMessages(sessionId: sessionId);
@@ -405,6 +411,7 @@ class LexiChatDataSource {
         oldestTs: metadata['oldest_ts']?.toString(),
       );
     } catch (e) {
+      if (_isSessionAccessError(e)) rethrow;
       logWarn(_tag, 'getMessagesMetadata failed, return empty metadata: $e');
       return const LexiMessagesMetadata(
         totalCount: 0,
@@ -468,6 +475,7 @@ class LexiChatDataSource {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
   }) async* {
     final payload = {
@@ -478,6 +486,7 @@ class LexiChatDataSource {
       if (audioBase64 != null) 'audio_base64': audioBase64,
       'enable_tts': enableTts,
       'learner_level': learnerLevel,
+      'native_language': nativeLanguage,
       if (storyContext != null) 'story_context': storyContext,
     };
 
diff --git a/flutter-app/lib/features/lexi_chat/data/repositories/lexi_chat_repository_impl.dart b/flutter-app/lib/features/lexi_chat/data/repositories/lexi_chat_repository_impl.dart
index 21139f59..22afee3e 100644
--- a/flutter-app/lib/features/lexi_chat/data/repositories/lexi_chat_repository_impl.dart
+++ b/flutter-app/lib/features/lexi_chat/data/repositories/lexi_chat_repository_impl.dart
@@ -28,6 +28,7 @@ class LexiChatRepositoryImpl implements LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
     String? idempotencyKey,
   }) {
@@ -39,6 +40,7 @@ class LexiChatRepositoryImpl implements LexiChatRepository {
       audioBase64: audioBase64,
       enableTts: enableTts,
       learnerLevel: learnerLevel,
+      nativeLanguage: nativeLanguage,
       storyContext: storyContext,
       idempotencyKey: idempotencyKey,
     );
@@ -88,7 +90,7 @@ class LexiChatRepositoryImpl implements LexiChatRepository {
         );
       }
     } catch (e) {
-      if (_isSessionNotFoundError(e)) {
+      if (_isSessionAccessError(e)) {
         // Let provider handle stale session cleanup and auto-create a new session.
         rethrow;
       }
@@ -110,6 +112,14 @@ class LexiChatRepositoryImpl implements LexiChatRepository {
         msg.contains('not found');
   }
 
+  bool _isSessionAccessError(Object error) {
+    final msg = error.toString().toLowerCase();
+    return _isSessionNotFoundError(error) ||
+        msg.contains('status 403') ||
+        msg.contains('403') ||
+        msg.contains('forbidden');
+  }
+
   @override
   Future<List<LexiSession>> getSessions({required String userId}) {
     return dataSource.getSessions(userId: userId);
@@ -137,6 +147,7 @@ class LexiChatRepositoryImpl implements LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
   }) {
     return dataSource.sendMessageStream(
@@ -147,6 +158,7 @@ class LexiChatRepositoryImpl implements LexiChatRepository {
       audioBase64: audioBase64,
       enableTts: enableTts,
       learnerLevel: learnerLevel,
+      nativeLanguage: nativeLanguage,
       storyContext: storyContext,
     );
   }
diff --git a/flutter-app/lib/features/lexi_chat/domain/repositories/lexi_chat_repository.dart b/flutter-app/lib/features/lexi_chat/domain/repositories/lexi_chat_repository.dart
index 23441cae..fafa0468 100644
--- a/flutter-app/lib/features/lexi_chat/domain/repositories/lexi_chat_repository.dart
+++ b/flutter-app/lib/features/lexi_chat/domain/repositories/lexi_chat_repository.dart
@@ -17,6 +17,7 @@ abstract class LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
     String? idempotencyKey,
   });
@@ -52,6 +53,7 @@ abstract class LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
   });
 }
diff --git a/flutter-app/lib/features/lexi_chat/presentation/pages/lexi_chat_page.dart b/flutter-app/lib/features/lexi_chat/presentation/pages/lexi_chat_page.dart
index 042dc082..d761fc29 100644
--- a/flutter-app/lib/features/lexi_chat/presentation/pages/lexi_chat_page.dart
+++ b/flutter-app/lib/features/lexi_chat/presentation/pages/lexi_chat_page.dart
@@ -51,7 +51,8 @@ class _LexiChatPageState extends State<LexiChatPage>
   bool _isWebSpeechActive = false;
   String _liveTranscript = '';
 
-  bool get _isVoiceActive => _isRecording || _isTranscribing || _isWebSpeechActive;
+  bool get _isVoiceActive =>
+      _isRecording || _isTranscribing || _isWebSpeechActive;
 
   int _lastMessageCount = 0;
   List<String> get _quickReplies => [
@@ -66,6 +67,7 @@ class _LexiChatPageState extends State<LexiChatPage>
     // Restore latest session first; create new only when needed.
     WidgetsBinding.instance.addPostFrameCallback((_) {
       final provider = context.read<LexiChatProvider>();
+      provider.setNativeLanguage(_nativeLanguage);
       unawaited(
         provider.restoreLatestSession(_userId).catchError((Object error) {
           debugPrint('restoreLatestSession failed: $error');
@@ -85,6 +87,18 @@ class _LexiChatPageState extends State<LexiChatPage>
     }
   }
 
+  String get _nativeLanguage {
+    try {
+      return Provider.of<AuthProvider>(
+            context,
+            listen: false,
+          ).user?.nativeLanguage ??
+          'vi';
+    } catch (_) {
+      return 'vi';
+    }
+  }
+
   @override
   void dispose() {
     _scrollController.removeListener(_handleTopReached);
@@ -158,12 +172,10 @@ class _LexiChatPageState extends State<LexiChatPage>
           _liveTranscript += result.transcript;
         }
         // Show accumulated + current interim text in input field live
-        final display = _liveTranscript +
-            (result.isFinal ? '' : result.transcript);
+        final display =
+            _liveTranscript + (result.isFinal ? '' : result.transcript);
         _controller.text = display;
-        _controller.selection = TextSelection.collapsed(
-          offset: display.length,
-        );
+        _controller.selection = TextSelection.collapsed(offset: display.length);
       },
       onError: (error) {
         setState(() => _isWebSpeechActive = false);
@@ -271,9 +283,7 @@ class _LexiChatPageState extends State<LexiChatPage>
         _isRecording = false;
         _isTranscribing = false;
       });
-      _showSnack(
-        'lexiChat.sttFailed'.tr(namedArgs: {'error': e.toString()}),
-      );
+      _showSnack('lexiChat.sttFailed'.tr(namedArgs: {'error': e.toString()}));
     }
   }
 
@@ -308,12 +318,18 @@ class _LexiChatPageState extends State<LexiChatPage>
           ),
         ),
         child: SafeArea(
-          child: Column(
-            children: [
-              _buildHeader(isDark),
-              Expanded(child: _buildMessageList(isDark)),
-              _buildInputBar(isDark),
-            ],
+          child: Align(
+            alignment: Alignment.topCenter,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 980),
+              child: Column(
+                children: [
+                  _buildHeader(isDark),
+                  Expanded(child: _buildMessageList(isDark)),
+                  _buildInputBar(isDark),
+                ],
+              ),
+            ),
           ),
         ),
       ),
@@ -414,7 +430,10 @@ class _LexiChatPageState extends State<LexiChatPage>
                         onTap: provider.cycleTtsSpeed,
                         borderRadius: BorderRadius.circular(12),
                         child: Padding(
-                          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 10),
+                          padding: const EdgeInsets.symmetric(
+                            horizontal: 10,
+                            vertical: 10,
+                          ),
                           child: Text(
                             provider.ttsSpeedLabel,
                             style: TextStyle(
@@ -736,20 +755,22 @@ class _LexiChatPageState extends State<LexiChatPage>
               margin: const EdgeInsets.only(bottom: 10),
               padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
               decoration: BoxDecoration(
-                color: (_isWebSpeechActive
-                        ? Colors.blue
-                        : _isTranscribing
+                color:
+                    (_isWebSpeechActive
+                            ? Colors.blue
+                            : _isTranscribing
                             ? Colors.orange
                             : Colors.red)
-                    .withValues(alpha: 0.08),
+                        .withValues(alpha: 0.08),
                 borderRadius: BorderRadius.circular(12),
                 border: Border.all(
-                  color: (_isWebSpeechActive
-                          ? Colors.blue
-                          : _isTranscribing
+                  color:
+                      (_isWebSpeechActive
+                              ? Colors.blue
+                              : _isTranscribing
                               ? Colors.orange
                               : Colors.red)
-                      .withValues(alpha: 0.2),
+                          .withValues(alpha: 0.2),
                 ),
               ),
               child: Row(
@@ -778,17 +799,19 @@ class _LexiChatPageState extends State<LexiChatPage>
                     _isTranscribing
                         ? 'lexiChat.transcribingStatus'.tr()
                         : _isWebSpeechActive
-                            ? 'lexiChat.webSpeechRecording'.tr()
-                            : 'lexiChat.recordingStatus'.tr(namedArgs: {
-                                'seconds':
-                                    _recordingDuration.inSeconds.toString(),
-                              }),
+                        ? 'lexiChat.webSpeechRecording'.tr()
+                        : 'lexiChat.recordingStatus'.tr(
+                            namedArgs: {
+                              'seconds': _recordingDuration.inSeconds
+                                  .toString(),
+                            },
+                          ),
                     style: TextStyle(
                       color: _isWebSpeechActive
                           ? Colors.blue
                           : _isTranscribing
-                              ? Colors.orange
-                              : AppColors.errorBright,
+                          ? Colors.orange
+                          : AppColors.errorBright,
                       fontWeight: FontWeight.w600,
                     ),
                   ),
@@ -921,8 +944,8 @@ class _LexiChatPageState extends State<LexiChatPage>
     final activeColor = _isWebSpeechActive
         ? Colors.blue
         : _isTranscribing
-            ? Colors.orange
-            : Colors.red;
+        ? Colors.orange
+        : Colors.red;
 
     Widget button = AnimatedContainer(
       duration: const Duration(milliseconds: 200),
diff --git a/flutter-app/lib/features/lexi_chat/presentation/providers/lexi_chat_provider.dart b/flutter-app/lib/features/lexi_chat/presentation/providers/lexi_chat_provider.dart
index 7c618abe..b0907cdd 100644
--- a/flutter-app/lib/features/lexi_chat/presentation/providers/lexi_chat_provider.dart
+++ b/flutter-app/lib/features/lexi_chat/presentation/providers/lexi_chat_provider.dart
@@ -36,6 +36,7 @@ class LexiChatProvider extends ChangeNotifier {
   final BackgroundSyncQueueService _syncQueue =
       BackgroundSyncQueueService.instance;
   StreamSubscription<SyncQueueItem>? _syncQueueSub;
+  bool _isDisposed = false;
 
   LexiChatProvider({required this.repository, required AiApiClient aiClient})
     : _aiClient = aiClient {
@@ -71,6 +72,7 @@ class LexiChatProvider extends ChangeNotifier {
   bool _ttsEnabled = true;
   double _ttsSpeed = 1.0;
   String _learnerLevel = 'B1';
+  String _nativeLanguage = 'vi';
   Timer? _typingStageTimer;
   DateTime? _responseStateStartedAt;
   int _requestSequence = 0;
@@ -114,7 +116,21 @@ class LexiChatProvider extends ChangeNotifier {
         normalized.contains('401');
   }
 
+  bool _isForbiddenSessionError(Object error) {
+    final normalized = error.toString().toLowerCase();
+    return normalized.contains('status 403') ||
+        normalized.contains('403') ||
+        normalized.contains('forbidden');
+  }
+
   String get learnerLevel => _learnerLevel;
+  String get nativeLanguage => _nativeLanguage;
+
+  @override
+  void notifyListeners() {
+    if (_isDisposed) return;
+    super.notifyListeners();
+  }
 
   // ── Session ────────────────────────────────────────────────────────────────
   Future<void> startSession(String userId) async {
@@ -180,6 +196,7 @@ class LexiChatProvider extends ChangeNotifier {
 
     try {
       await syncSessions(userId);
+      await _removeSessionsForOtherUsers(userId);
 
       if (_sessions.isNotEmpty) {
         await selectSession(_sessions.first);
@@ -291,6 +308,20 @@ class LexiChatProvider extends ChangeNotifier {
         return;
       }
 
+      if (_isForbiddenSessionError(e)) {
+        _sessions.removeWhere((s) => s.sessionId == summary.sessionId);
+        await _saveSessions();
+        _session = null;
+        _messages.clear();
+        _isLoadingMoreMessages = false;
+        _hasMoreMessages = false;
+        _nextMessageCursor = null;
+        _error = 'This session belongs to another account. Start a new chat.';
+        _isLoading = false;
+        notifyListeners();
+        return;
+      }
+
       _error = 'Failed to load session: $e';
       if (_isUnauthorizedError(e)) {
         _error = 'Your login session expired. Please sign in again.';
@@ -384,6 +415,7 @@ class LexiChatProvider extends ChangeNotifier {
         message: text.trim(),
         enableTts: _ttsEnabled,
         learnerLevel: _learnerLevel,
+        nativeLanguage: _nativeLanguage,
         idempotencyKey: requestId,
       );
 
@@ -448,6 +480,7 @@ class LexiChatProvider extends ChangeNotifier {
         'input_type': 'text',
         'enable_tts': _ttsEnabled,
         'learner_level': _learnerLevel,
+        'native_language': _nativeLanguage,
       },
     );
   }
@@ -533,6 +566,7 @@ class LexiChatProvider extends ChangeNotifier {
         message: text.trim(),
         enableTts: _ttsEnabled,
         learnerLevel: _learnerLevel,
+        nativeLanguage: _nativeLanguage,
       )) {
         switch (event) {
           case LexiStreamThinking():
@@ -570,8 +604,8 @@ class LexiChatProvider extends ChangeNotifier {
               final finalContent = serverText.isNotEmpty
                   ? serverText
                   : (accumulated.isNotEmpty
-                      ? accumulated
-                      : 'Squawk! Something went quiet. Can you ask that again?');
+                        ? accumulated
+                        : 'Squawk! Something went quiet. Can you ask that again?');
               _messages[idx] = LexiMessage(
                 id: messageId.isNotEmpty ? messageId : placeholderId,
                 role: 'assistant',
@@ -736,6 +770,7 @@ class LexiChatProvider extends ChangeNotifier {
         audioBase64: audioBase64,
         enableTts: _ttsEnabled,
         learnerLevel: _learnerLevel,
+        nativeLanguage: _nativeLanguage,
       );
 
       _messages.add(response);
@@ -859,6 +894,12 @@ class LexiChatProvider extends ChangeNotifier {
     notifyListeners();
   }
 
+  void setNativeLanguage(String language) {
+    if (language.isEmpty || language == _nativeLanguage) return;
+    _nativeLanguage = language;
+    notifyListeners();
+  }
+
   // ── Cleanup ───────────────────────────────────────────────────────────────
   void clearError() {
     _error = null;
@@ -867,6 +908,7 @@ class LexiChatProvider extends ChangeNotifier {
 
   @override
   void dispose() {
+    _isDisposed = true;
     _syncQueueSub?.cancel();
     _typingStageTimer?.cancel();
     _ttsPlayer.dispose();
@@ -928,6 +970,15 @@ class LexiChatProvider extends ChangeNotifier {
     }
   }
 
+  Future<void> _removeSessionsForOtherUsers(String userId) async {
+    final before = _sessions.length;
+    _sessions.removeWhere((s) => s.userId.isNotEmpty && s.userId != userId);
+    if (_sessions.length != before) {
+      await _saveSessions();
+      notifyListeners();
+    }
+  }
+
   Future<void> _loadSavedSessions() async {
     _isLoadingSessions = true;
     notifyListeners();
diff --git a/flutter-app/lib/features/mistakes/data/mistake_notebook_remote_datasource.dart b/flutter-app/lib/features/mistakes/data/mistake_notebook_remote_datasource.dart
new file mode 100644
index 00000000..37043d76
--- /dev/null
+++ b/flutter-app/lib/features/mistakes/data/mistake_notebook_remote_datasource.dart
@@ -0,0 +1,78 @@
+import 'package:lexilingo_app/core/network/api_client.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+
+abstract class MistakeNotebookRemoteDataSource {
+  Future<List<MistakeNotebookEntry>> getEntries({String status = 'all'});
+
+  Future<MistakeNotebookEntry> saveMistake(MistakeNotebookEntry entry);
+
+  Future<MistakeNotebookEntry> markReviewed(String id);
+
+  Future<MistakeNotebookEntry> reopen(String id);
+
+  Future<void> delete(String id);
+}
+
+class ApiMistakeNotebookRemoteDataSource
+    implements MistakeNotebookRemoteDataSource {
+  final ApiClient apiClient;
+
+  ApiMistakeNotebookRemoteDataSource({required this.apiClient});
+
+  @override
+  Future<List<MistakeNotebookEntry>> getEntries({String status = 'all'}) async {
+    const limit = 100;
+    var offset = 0;
+    final entries = <MistakeNotebookEntry>[];
+
+    while (true) {
+      final path = Uri(
+        path: '/mistakes',
+        queryParameters: {
+          'status': status,
+          'limit': '$limit',
+          'offset': '$offset',
+        },
+      ).toString();
+      final response = await apiClient.get(path);
+      final rawItems = response['data'];
+      if (rawItems is! List) return entries;
+
+      final pageEntries = rawItems
+          .whereType<Map<String, dynamic>>()
+          .map(MistakeNotebookEntry.fromJson)
+          .where((entry) => entry.id.isNotEmpty)
+          .toList();
+      entries.addAll(pageEntries);
+
+      if (pageEntries.length < limit) return entries;
+      offset += limit;
+    }
+  }
+
+  @override
+  Future<MistakeNotebookEntry> saveMistake(MistakeNotebookEntry entry) async {
+    final response = await apiClient.post('/mistakes', body: entry.toJson());
+    return MistakeNotebookEntry.fromJson(response);
+  }
+
+  @override
+  Future<MistakeNotebookEntry> markReviewed(String id) async {
+    final encodedId = Uri.encodeComponent(id);
+    final response = await apiClient.patch('/mistakes/$encodedId/review');
+    return MistakeNotebookEntry.fromJson(response);
+  }
+
+  @override
+  Future<MistakeNotebookEntry> reopen(String id) async {
+    final encodedId = Uri.encodeComponent(id);
+    final response = await apiClient.patch('/mistakes/$encodedId/reopen');
+    return MistakeNotebookEntry.fromJson(response);
+  }
+
+  @override
+  Future<void> delete(String id) async {
+    final encodedId = Uri.encodeComponent(id);
+    await apiClient.delete('/mistakes/$encodedId');
+  }
+}
diff --git a/flutter-app/lib/features/mistakes/data/mistake_notebook_repository.dart b/flutter-app/lib/features/mistakes/data/mistake_notebook_repository.dart
new file mode 100644
index 00000000..5a6c13c2
--- /dev/null
+++ b/flutter-app/lib/features/mistakes/data/mistake_notebook_repository.dart
@@ -0,0 +1,261 @@
+import 'dart:convert';
+
+import 'package:lexilingo_app/core/di/service_locator.dart';
+import 'package:lexilingo_app/core/network/api_client.dart';
+import 'package:lexilingo_app/core/services/user_scope_service.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_remote_datasource.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class MistakeNotebookRepository {
+  static const _storageKey = 'mistake_notebook_entries_v1';
+  static const _pendingOpsKey = 'mistake_notebook_pending_ops_v1';
+
+  final Future<SharedPreferences> Function() _prefsFactory;
+  final MistakeNotebookRemoteDataSource? _remoteDataSource;
+  final bool _syncEnabled;
+
+  const MistakeNotebookRepository({
+    Future<SharedPreferences> Function()? prefsFactory,
+    MistakeNotebookRemoteDataSource? remoteDataSource,
+    bool syncEnabled = true,
+  }) : _prefsFactory = prefsFactory ?? SharedPreferences.getInstance,
+       _remoteDataSource = remoteDataSource,
+       _syncEnabled = syncEnabled;
+
+  Future<List<MistakeNotebookEntry>> getEntries() async {
+    final localEntries = await _getLocalEntries();
+    final remote = _remote;
+    if (remote == null) return localEntries;
+
+    try {
+      await _flushPendingOps(remote);
+      final pendingIds = await _pendingEntryIds();
+      final remoteEntries = (await remote.getEntries(
+        status: 'all',
+      )).where((entry) => !pendingIds.contains(entry.id)).toList();
+      final merged = _mergeEntries(localEntries, remoteEntries);
+      await _saveEntries(merged);
+      return sortMistakes(merged);
+    } catch (_) {
+      return localEntries;
+    }
+  }
+
+  Future<void> saveMistake(MistakeNotebookEntry entry) async {
+    final entries = (await _getLocalEntries()).toList();
+    final index = entries.indexWhere((item) => item.id == entry.id);
+
+    final nextEntry = index == -1
+        ? entry
+        : entry.copyWith(
+            reviewCount: entries[index].reviewCount,
+            clearReviewedAt: true,
+          );
+
+    if (index == -1) {
+      entries.add(nextEntry);
+    } else {
+      entries[index] = nextEntry;
+    }
+
+    await _saveEntries(sortMistakes(entries));
+    await _syncOrQueue({'type': 'upsert', 'entry': nextEntry.toJson()});
+  }
+
+  Future<void> markReviewed(String id) async {
+    final entries = (await _getLocalEntries()).toList();
+    final index = entries.indexWhere((entry) => entry.id == id);
+    if (index == -1) return;
+
+    entries[index] = entries[index].copyWith(
+      reviewedAt: DateTime.now(),
+      reviewCount: entries[index].reviewCount + 1,
+    );
+    await _saveEntries(sortMistakes(entries));
+    await _syncOrQueue({'type': 'review', 'id': id});
+  }
+
+  Future<void> delete(String id) async {
+    final entries = (await _getLocalEntries()).toList();
+    entries.removeWhere((entry) => entry.id == id);
+    await _saveEntries(entries);
+    await _syncOrQueue({'type': 'delete', 'id': id});
+  }
+
+  Future<void> clearReviewed() async {
+    final entries = (await _getLocalEntries()).toList();
+    final reviewedIds = entries
+        .where((entry) => entry.isReviewed)
+        .map((entry) => entry.id)
+        .toList();
+    entries.removeWhere((entry) => entry.isReviewed);
+    await _saveEntries(entries);
+
+    for (final id in reviewedIds) {
+      await _syncOrQueue({'type': 'delete', 'id': id});
+    }
+  }
+
+  MistakeNotebookRemoteDataSource? get _remote {
+    if (!_syncEnabled) return null;
+    if (_remoteDataSource != null) return _remoteDataSource;
+    if (!sl.isRegistered<ApiClient>()) return null;
+    return ApiMistakeNotebookRemoteDataSource(apiClient: sl<ApiClient>());
+  }
+
+  Future<List<MistakeNotebookEntry>> _getLocalEntries() async {
+    final prefs = await _prefsFactory();
+    final raw = prefs.getString(await _scopedKey(_storageKey));
+    if (raw == null || raw.isEmpty) return const [];
+
+    try {
+      final decoded = jsonDecode(raw) as List<dynamic>;
+      return sortMistakes(
+        decoded
+            .whereType<Map<String, dynamic>>()
+            .map(MistakeNotebookEntry.fromJson)
+            .where((entry) => entry.id.isNotEmpty)
+            .toList(),
+      );
+    } catch (_) {
+      return const [];
+    }
+  }
+
+  Future<void> _saveEntries(List<MistakeNotebookEntry> entries) async {
+    final prefs = await _prefsFactory();
+    await prefs.setString(
+      await _scopedKey(_storageKey),
+      jsonEncode(entries.map((entry) => entry.toJson()).toList()),
+    );
+  }
+
+  Future<void> _syncOrQueue(Map<String, dynamic> op) async {
+    final remote = _remote;
+    if (remote == null) {
+      await _queuePendingOp(op);
+      return;
+    }
+
+    try {
+      await _flushPendingOps(remote);
+      await _applyRemoteOp(remote, op);
+    } catch (_) {
+      await _queuePendingOp(op);
+    }
+  }
+
+  Future<void> _flushPendingOps(MistakeNotebookRemoteDataSource remote) async {
+    final prefs = await _prefsFactory();
+    final pendingOpsKey = await _scopedKey(_pendingOpsKey);
+    final ops = _decodePendingOps(prefs.getString(pendingOpsKey));
+    if (ops.isEmpty) return;
+
+    final remaining = <Map<String, dynamic>>[];
+    for (var index = 0; index < ops.length; index++) {
+      final op = ops[index];
+      try {
+        await _applyRemoteOp(remote, op);
+      } catch (_) {
+        remaining.add(op);
+        remaining.addAll(ops.skip(index + 1));
+        break;
+      }
+    }
+
+    await prefs.setString(pendingOpsKey, jsonEncode(remaining));
+  }
+
+  Future<void> _queuePendingOp(Map<String, dynamic> op) async {
+    final prefs = await _prefsFactory();
+    final pendingOpsKey = await _scopedKey(_pendingOpsKey);
+    final ops = _decodePendingOps(prefs.getString(pendingOpsKey));
+    ops.add(op);
+    await prefs.setString(pendingOpsKey, jsonEncode(ops));
+  }
+
+  Future<void> _applyRemoteOp(
+    MistakeNotebookRemoteDataSource remote,
+    Map<String, dynamic> op,
+  ) async {
+    switch (op['type']) {
+      case 'upsert':
+        final rawEntry = op['entry'];
+        if (rawEntry is Map<String, dynamic>) {
+          await remote.saveMistake(MistakeNotebookEntry.fromJson(rawEntry));
+        }
+        break;
+      case 'review':
+        final id = op['id'] as String?;
+        if (id != null && id.isNotEmpty) await remote.markReviewed(id);
+        break;
+      case 'delete':
+        final id = op['id'] as String?;
+        if (id != null && id.isNotEmpty) await remote.delete(id);
+        break;
+    }
+  }
+
+  List<Map<String, dynamic>> _decodePendingOps(String? raw) {
+    if (raw == null || raw.isEmpty) return [];
+    try {
+      final decoded = jsonDecode(raw) as List<dynamic>;
+      return decoded.whereType<Map<String, dynamic>>().toList();
+    } catch (_) {
+      return [];
+    }
+  }
+
+  Future<Set<String>> _pendingEntryIds() async {
+    final prefs = await _prefsFactory();
+    final ops = _decodePendingOps(
+      prefs.getString(await _scopedKey(_pendingOpsKey)),
+    );
+    final ids = <String>{};
+    for (final op in ops) {
+      final id = op['id'] as String?;
+      if (id != null && id.isNotEmpty) {
+        ids.add(id);
+        continue;
+      }
+      final rawEntry = op['entry'];
+      if (rawEntry is Map<String, dynamic>) {
+        final entryId = rawEntry['id'] as String?;
+        if (entryId != null && entryId.isNotEmpty) ids.add(entryId);
+      }
+    }
+    return ids;
+  }
+
+  List<MistakeNotebookEntry> _mergeEntries(
+    List<MistakeNotebookEntry> localEntries,
+    List<MistakeNotebookEntry> remoteEntries,
+  ) {
+    final merged = <String, MistakeNotebookEntry>{};
+    for (final entry in [...remoteEntries, ...localEntries]) {
+      final current = merged[entry.id];
+      if (current == null || !entry.createdAt.isBefore(current.createdAt)) {
+        merged[entry.id] = entry;
+      }
+    }
+    return sortMistakes(merged.values.toList());
+  }
+
+  Future<String> _scopedKey(String baseKey) async {
+    final scope = await UserScopeService.getScopeOrDefault();
+    if (scope == 'anonymous') return baseKey;
+    return '$baseKey:$scope';
+  }
+}
+
+List<MistakeNotebookEntry> sortMistakes(List<MistakeNotebookEntry> entries) {
+  final sorted = [...entries];
+  sorted.sort((a, b) {
+    if (a.isReviewed != b.isReviewed) {
+      return a.isReviewed ? 1 : -1;
+    }
+    return b.createdAt.compareTo(a.createdAt);
+  });
+  return sorted;
+}
diff --git a/flutter-app/lib/features/mistakes/domain/mistake_notebook_entry.dart b/flutter-app/lib/features/mistakes/domain/mistake_notebook_entry.dart
new file mode 100644
index 00000000..b1ed0d6f
--- /dev/null
+++ b/flutter-app/lib/features/mistakes/domain/mistake_notebook_entry.dart
@@ -0,0 +1,115 @@
+class MistakeNotebookEntry {
+  final String id;
+  final String sourceType;
+  final String sourceId;
+  final String sourceTitle;
+  final String question;
+  final String selectedAnswer;
+  final String correctAnswer;
+  final String explanation;
+  final String skill;
+  final DateTime createdAt;
+  final DateTime? reviewedAt;
+  final int reviewCount;
+
+  const MistakeNotebookEntry({
+    required this.id,
+    required this.sourceType,
+    required this.sourceId,
+    required this.sourceTitle,
+    required this.question,
+    required this.selectedAnswer,
+    required this.correctAnswer,
+    required this.explanation,
+    required this.skill,
+    required this.createdAt,
+    this.reviewedAt,
+    this.reviewCount = 0,
+  });
+
+  bool get isReviewed => reviewedAt != null;
+
+  MistakeNotebookEntry copyWith({
+    String? id,
+    String? sourceType,
+    String? sourceId,
+    String? sourceTitle,
+    String? question,
+    String? selectedAnswer,
+    String? correctAnswer,
+    String? explanation,
+    String? skill,
+    DateTime? createdAt,
+    DateTime? reviewedAt,
+    bool clearReviewedAt = false,
+    int? reviewCount,
+  }) {
+    return MistakeNotebookEntry(
+      id: id ?? this.id,
+      sourceType: sourceType ?? this.sourceType,
+      sourceId: sourceId ?? this.sourceId,
+      sourceTitle: sourceTitle ?? this.sourceTitle,
+      question: question ?? this.question,
+      selectedAnswer: selectedAnswer ?? this.selectedAnswer,
+      correctAnswer: correctAnswer ?? this.correctAnswer,
+      explanation: explanation ?? this.explanation,
+      skill: skill ?? this.skill,
+      createdAt: createdAt ?? this.createdAt,
+      reviewedAt: clearReviewedAt ? null : reviewedAt ?? this.reviewedAt,
+      reviewCount: reviewCount ?? this.reviewCount,
+    );
+  }
+
+  Map<String, dynamic> toJson() => {
+    'id': id,
+    'source_type': sourceType,
+    'source_id': sourceId,
+    'source_title': sourceTitle,
+    'question': question,
+    'selected_answer': selectedAnswer,
+    'correct_answer': correctAnswer,
+    'explanation': explanation,
+    'skill': skill,
+    'created_at': createdAt.toIso8601String(),
+    'reviewed_at': reviewedAt?.toIso8601String(),
+    'review_count': reviewCount,
+  };
+
+  factory MistakeNotebookEntry.fromJson(Map<String, dynamic> json) {
+    return MistakeNotebookEntry(
+      id: json['id'] as String? ?? '',
+      sourceType: json['source_type'] as String? ?? '',
+      sourceId: json['source_id'] as String? ?? '',
+      sourceTitle: json['source_title'] as String? ?? '',
+      question: json['question'] as String? ?? '',
+      selectedAnswer: json['selected_answer'] as String? ?? '',
+      correctAnswer: json['correct_answer'] as String? ?? '',
+      explanation: json['explanation'] as String? ?? '',
+      skill: json['skill'] as String? ?? '',
+      createdAt:
+          DateTime.tryParse(json['created_at'] as String? ?? '') ??
+          DateTime.now(),
+      reviewedAt: DateTime.tryParse(json['reviewed_at'] as String? ?? ''),
+      reviewCount: (json['review_count'] as num?)?.toInt() ?? 0,
+    );
+  }
+
+  static String buildId({
+    required String sourceType,
+    required String sourceId,
+    required String questionId,
+    required String selectedAnswer,
+  }) {
+    final raw = '$sourceType|$sourceId|$questionId|$selectedAnswer';
+    return 'mistake_${_stableHash(raw).toRadixString(16)}';
+  }
+
+  static int _stableHash(String value) {
+    var hash = 0x811c9dc5;
+    for (final unit in value.codeUnits) {
+      hash ^= unit;
+      hash = (hash * 0x01000193) & 0xffffffff;
+    }
+    return hash;
+  }
+}
diff --git a/flutter-app/lib/features/mistakes/presentation/pages/mistake_notebook_page.dart b/flutter-app/lib/features/mistakes/presentation/pages/mistake_notebook_page.dart
new file mode 100644
index 00000000..55627f76
--- /dev/null
+++ b/flutter-app/lib/features/mistakes/presentation/pages/mistake_notebook_page.dart
@@ -0,0 +1,619 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+
+enum _MistakeFilter { all, unreviewed, reviewed }
+
+class MistakeNotebookPage extends StatefulWidget {
+  final MistakeNotebookRepository repository;
+
+  const MistakeNotebookPage({
+    super.key,
+    this.repository = const MistakeNotebookRepository(),
+  });
+
+  @override
+  State<MistakeNotebookPage> createState() => _MistakeNotebookPageState();
+}
+
+class _MistakeNotebookPageState extends State<MistakeNotebookPage> {
+  List<MistakeNotebookEntry> _entries = const [];
+  _MistakeFilter _filter = _MistakeFilter.all;
+  bool _isLoading = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _loadEntries();
+  }
+
+  Future<void> _loadEntries() async {
+    setState(() => _isLoading = true);
+    final entries = await widget.repository.getEntries();
+    if (!mounted) return;
+    setState(() {
+      _entries = entries;
+      _isLoading = false;
+    });
+  }
+
+  Future<void> _markReviewed(String id) async {
+    await widget.repository.markReviewed(id);
+    await _loadEntries();
+  }
+
+  Future<void> _deleteEntry(MistakeNotebookEntry entry) async {
+    final shouldDelete = await showDialog<bool>(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: Text('mistakeNotebook.deleteTitle'.tr()),
+        content: Text('mistakeNotebook.deleteMessage'.tr()),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(false),
+            child: Text('common.cancel'.tr()),
+          ),
+          FilledButton(
+            onPressed: () => Navigator.of(context).pop(true),
+            child: Text('mistakeNotebook.delete'.tr()),
+          ),
+        ],
+      ),
+    );
+    if (shouldDelete != true) return;
+
+    await widget.repository.delete(entry.id);
+    await _loadEntries();
+  }
+
+  List<MistakeNotebookEntry> get _filteredEntries {
+    return switch (_filter) {
+      _MistakeFilter.all => _entries,
+      _MistakeFilter.unreviewed =>
+        _entries.where((entry) => !entry.isReviewed).toList(growable: false),
+      _MistakeFilter.reviewed =>
+        _entries.where((entry) => entry.isReviewed).toList(growable: false),
+    };
+  }
+
+  int get _unreviewedCount =>
+      _entries.where((entry) => !entry.isReviewed).length;
+
+  int get _reviewedCount => _entries.where((entry) => entry.isReviewed).length;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Scaffold(
+      backgroundColor: isDark
+          ? AppColors.backgroundDark
+          : AppColors.backgroundLight,
+      appBar: AppBar(
+        title: Text('mistakeNotebook.title'.tr()),
+        actions: [
+          IconButton(
+            tooltip: 'common.refresh'.tr(),
+            onPressed: _loadEntries,
+            icon: const Icon(Icons.refresh_rounded),
+          ),
+        ],
+      ),
+      body: _isLoading
+          ? const Center(child: CircularProgressIndicator())
+          : RefreshIndicator(
+              onRefresh: _loadEntries,
+              child: ListView(
+                physics: const AlwaysScrollableScrollPhysics(),
+                padding: const EdgeInsets.fromLTRB(16, 12, 16, 24),
+                children: [
+                  _NotebookHeader(
+                    total: _entries.length,
+                    unreviewed: _unreviewedCount,
+                    reviewed: _reviewedCount,
+                  ),
+                  const SizedBox(height: 14),
+                  _FilterRow(
+                    selected: _filter,
+                    onChanged: (filter) => setState(() => _filter = filter),
+                  ),
+                  const SizedBox(height: 14),
+                  if (_filteredEntries.isEmpty)
+                    _NotebookEmptyState(hasAnyEntry: _entries.isNotEmpty)
+                  else
+                    for (final entry in _filteredEntries) ...[
+                      _MistakeCard(
+                        entry: entry,
+                        onMarkReviewed: () => _markReviewed(entry.id),
+                        onDelete: () => _deleteEntry(entry),
+                      ),
+                      const SizedBox(height: 12),
+                    ],
+                ],
+              ),
+            ),
+    );
+  }
+}
+
+class _NotebookHeader extends StatelessWidget {
+  const _NotebookHeader({
+    required this.total,
+    required this.unreviewed,
+    required this.reviewed,
+  });
+
+  final int total;
+  final int unreviewed;
+  final int reviewed;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+
+    return Container(
+      padding: const EdgeInsets.all(18),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(
+          color: isDark ? AppColors.borderDarkSoft : AppColors.slate200,
+        ),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              Container(
+                width: 46,
+                height: 46,
+                decoration: BoxDecoration(
+                  color: accent.withValues(alpha: isDark ? 0.2 : 0.12),
+                  borderRadius: BorderRadius.circular(14),
+                ),
+                child: Icon(Icons.rule_folder_rounded, color: accent),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      'mistakeNotebook.heroTitle'.tr(),
+                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
+                        fontWeight: FontWeight.w900,
+                      ),
+                    ),
+                    const SizedBox(height: 3),
+                    Text(
+                      'mistakeNotebook.heroSubtitle'.tr(),
+                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                        color: AppColorRoles.textSecondary(isDark),
+                        height: 1.35,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 16),
+          Row(
+            children: [
+              Expanded(
+                child: _HeaderMetric(
+                  value: '$total',
+                  label: 'mistakeNotebook.total'.tr(),
+                ),
+              ),
+              const SizedBox(width: 10),
+              Expanded(
+                child: _HeaderMetric(
+                  value: '$unreviewed',
+                  label: 'mistakeNotebook.toReview'.tr(),
+                ),
+              ),
+              const SizedBox(width: 10),
+              Expanded(
+                child: _HeaderMetric(
+                  value: '$reviewed',
+                  label: 'mistakeNotebook.reviewed'.tr(),
+                ),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _HeaderMetric extends StatelessWidget {
+  const _HeaderMetric({required this.value, required this.label});
+
+  final String value;
+  final String label;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 10),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkInput : AppColors.grey50,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            value,
+            maxLines: 1,
+            overflow: TextOverflow.ellipsis,
+            style: Theme.of(
+              context,
+            ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w900),
+          ),
+          const SizedBox(height: 2),
+          Text(
+            label,
+            maxLines: 1,
+            overflow: TextOverflow.ellipsis,
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: AppColorRoles.textSecondary(isDark),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _FilterRow extends StatelessWidget {
+  const _FilterRow({required this.selected, required this.onChanged});
+
+  final _MistakeFilter selected;
+  final ValueChanged<_MistakeFilter> onChanged;
+
+  @override
+  Widget build(BuildContext context) {
+    return Wrap(
+      spacing: 8,
+      runSpacing: 8,
+      children: [
+        _FilterChipButton(
+          label: 'mistakeNotebook.filterAll'.tr(),
+          selected: selected == _MistakeFilter.all,
+          onSelected: () => onChanged(_MistakeFilter.all),
+        ),
+        _FilterChipButton(
+          label: 'mistakeNotebook.filterToReview'.tr(),
+          selected: selected == _MistakeFilter.unreviewed,
+          onSelected: () => onChanged(_MistakeFilter.unreviewed),
+        ),
+        _FilterChipButton(
+          label: 'mistakeNotebook.filterReviewed'.tr(),
+          selected: selected == _MistakeFilter.reviewed,
+          onSelected: () => onChanged(_MistakeFilter.reviewed),
+        ),
+      ],
+    );
+  }
+}
+
+class _FilterChipButton extends StatelessWidget {
+  const _FilterChipButton({
+    required this.label,
+    required this.selected,
+    required this.onSelected,
+  });
+
+  final String label;
+  final bool selected;
+  final VoidCallback onSelected;
+
+  @override
+  Widget build(BuildContext context) {
+    return ChoiceChip(
+      label: Text(label),
+      selected: selected,
+      onSelected: (_) => onSelected(),
+      labelStyle: TextStyle(
+        fontWeight: FontWeight.w700,
+        color: selected ? Colors.white : null,
+      ),
+      selectedColor: AppColorRoles.primary(
+        Theme.of(context).brightness == Brightness.dark,
+      ),
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+    );
+  }
+}
+
+class _NotebookEmptyState extends StatelessWidget {
+  const _NotebookEmptyState({required this.hasAnyEntry});
+
+  final bool hasAnyEntry;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.all(24),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(
+          color: isDark ? AppColors.borderDarkSoft : AppColors.slate200,
+        ),
+      ),
+      child: Column(
+        children: [
+          Icon(
+            hasAnyEntry
+                ? Icons.check_circle_rounded
+                : Icons.auto_stories_rounded,
+            size: 42,
+            color: hasAnyEntry
+                ? AppColors.greenSuccessBright
+                : AppColorRoles.primary(isDark),
+          ),
+          const SizedBox(height: 12),
+          Text(
+            hasAnyEntry
+                ? 'mistakeNotebook.emptyFilterTitle'.tr()
+                : 'mistakeNotebook.emptyTitle'.tr(),
+            textAlign: TextAlign.center,
+            style: Theme.of(
+              context,
+            ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w900),
+          ),
+          const SizedBox(height: 6),
+          Text(
+            hasAnyEntry
+                ? 'mistakeNotebook.emptyFilterSubtitle'.tr()
+                : 'mistakeNotebook.emptySubtitle'.tr(),
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: AppColorRoles.textSecondary(isDark),
+              height: 1.35,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _MistakeCard extends StatelessWidget {
+  const _MistakeCard({
+    required this.entry,
+    required this.onMarkReviewed,
+    required this.onDelete,
+  });
+
+  final MistakeNotebookEntry entry;
+  final VoidCallback onMarkReviewed;
+  final VoidCallback onDelete;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final sourceLabel = _sourceLabel(entry.sourceType);
+    final dateText = DateFormat.yMMMd().format(entry.createdAt);
+
+    return Container(
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(
+          color: entry.isReviewed
+              ? AppColors.greenSuccessBright.withValues(alpha: 0.4)
+              : AppColors.errorBright.withValues(alpha: isDark ? 0.45 : 0.3),
+        ),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      sourceLabel,
+                      style: Theme.of(context).textTheme.labelMedium?.copyWith(
+                        color: AppColorRoles.primary(isDark),
+                        fontWeight: FontWeight.w900,
+                      ),
+                    ),
+                    const SizedBox(height: 3),
+                    Text(
+                      entry.sourceTitle.isEmpty
+                          ? sourceLabel
+                          : entry.sourceTitle,
+                      maxLines: 2,
+                      overflow: TextOverflow.ellipsis,
+                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                        color: AppColorRoles.textSecondary(isDark),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+              Text(
+                dateText,
+                style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                  color: AppColorRoles.textSecondary(isDark),
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 14),
+          Text(
+            entry.question,
+            style: Theme.of(
+              context,
+            ).textTheme.titleSmall?.copyWith(fontWeight: FontWeight.w800),
+          ),
+          const SizedBox(height: 14),
+          _AnswerLine(
+            icon: Icons.close_rounded,
+            iconColor: AppColors.errorBright,
+            label: 'mistakeNotebook.yourAnswer'.tr(),
+            value: entry.selectedAnswer,
+          ),
+          const SizedBox(height: 8),
+          _AnswerLine(
+            icon: Icons.check_rounded,
+            iconColor: AppColors.greenSuccessBright,
+            label: 'mistakeNotebook.correctAnswer'.tr(),
+            value: entry.correctAnswer,
+          ),
+          if (entry.explanation.isNotEmpty) ...[
+            const SizedBox(height: 12),
+            Text(
+              'mistakeNotebook.explanation'.tr(),
+              style: Theme.of(
+                context,
+              ).textTheme.labelMedium?.copyWith(fontWeight: FontWeight.w900),
+            ),
+            const SizedBox(height: 4),
+            Text(
+              entry.explanation,
+              style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: AppColorRoles.textSecondary(isDark),
+                height: 1.35,
+              ),
+            ),
+          ],
+          const SizedBox(height: 14),
+          Row(
+            children: [
+              if (entry.isReviewed)
+                _ReviewedPill(reviewCount: entry.reviewCount)
+              else
+                OutlinedButton.icon(
+                  onPressed: onMarkReviewed,
+                  icon: const Icon(Icons.done_rounded, size: 18),
+                  label: Text('mistakeNotebook.markReviewed'.tr()),
+                ),
+              const Spacer(),
+              IconButton(
+                tooltip: 'mistakeNotebook.delete'.tr(),
+                onPressed: onDelete,
+                icon: const Icon(Icons.delete_outline_rounded),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+
+  String _sourceLabel(String sourceType) {
+    return switch (sourceType) {
+      'book_quiz' => 'mistakeNotebook.sourceBookQuiz'.tr(),
+      'news_quiz' => 'mistakeNotebook.sourceNewsQuiz'.tr(),
+      'game_fill_blank' => 'mistakeNotebook.sourceFillBlank'.tr(),
+      'game_grammar_quiz' => 'mistakeNotebook.sourceGrammarQuiz'.tr(),
+      _ => 'mistakeNotebook.sourceQuiz'.tr(),
+    };
+  }
+}
+
+class _AnswerLine extends StatelessWidget {
+  const _AnswerLine({
+    required this.icon,
+    required this.iconColor,
+    required this.label,
+    required this.value,
+  });
+
+  final IconData icon;
+  final Color iconColor;
+  final String label;
+  final String value;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Row(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Icon(icon, color: iconColor, size: 18),
+        const SizedBox(width: 8),
+        Expanded(
+          child: RichText(
+            text: TextSpan(
+              style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: AppColorRoles.textSecondary(isDark),
+                height: 1.35,
+              ),
+              children: [
+                TextSpan(
+                  text: '$label: ',
+                  style: TextStyle(
+                    color: AppColorRoles.textPrimary(isDark),
+                    fontWeight: FontWeight.w800,
+                  ),
+                ),
+                TextSpan(text: value.isEmpty ? '-' : value),
+              ],
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _ReviewedPill extends StatelessWidget {
+  const _ReviewedPill({required this.reviewCount});
+
+  final int reviewCount;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 7),
+      decoration: BoxDecoration(
+        color: AppColors.greenSuccessBright.withValues(alpha: 0.12),
+        borderRadius: BorderRadius.circular(999),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          const Icon(
+            Icons.check_circle_rounded,
+            color: AppColors.greenSuccessBright,
+            size: 16,
+          ),
+          const SizedBox(width: 6),
+          Text(
+            reviewCount > 1
+                ? 'mistakeNotebook.reviewedTimes'.tr(
+                    namedArgs: {'count': '$reviewCount'},
+                  )
+                : 'mistakeNotebook.reviewed'.tr(),
+            style: const TextStyle(
+              color: AppColors.greenSuccessBright,
+              fontWeight: FontWeight.w800,
+              fontSize: 12,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/news/presentation/providers/news_provider.dart b/flutter-app/lib/features/news/presentation/providers/news_provider.dart
index 9dc537e2..51555ab5 100644
--- a/flutter-app/lib/features/news/presentation/providers/news_provider.dart
+++ b/flutter-app/lib/features/news/presentation/providers/news_provider.dart
@@ -1,4 +1,9 @@
+import 'dart:async';
+
 import 'package:flutter/foundation.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+
 import '../../data/repositories/news_repository.dart';
 import '../../domain/entities/news_entities.dart';
 
@@ -7,14 +12,21 @@ import '../../domain/entities/news_entities.dart';
 /// Phase 2: News Reading.
 class NewsProvider extends ChangeNotifier {
   final NewsRepository _repository;
+  final MistakeNotebookRepository _mistakeRepository;
 
-  NewsProvider({NewsRepository? repository})
-    : _repository = repository ?? NewsRepository();
+  NewsProvider({
+    NewsRepository? repository,
+    MistakeNotebookRepository? mistakeRepository,
+  }) : _repository = repository ?? NewsRepository(),
+       _mistakeRepository =
+           mistakeRepository ?? const MistakeNotebookRepository();
 
   // ── State ──
   List<NewsArticle> _articles = [];
   List<NewsCategory> _categories = [];
   NewsQuiz? _currentQuiz;
+  String? _currentQuizArticleId;
+  NewsArticle? _currentQuizArticle;
   bool _isLoading = false;
   bool _isLoadingQuiz = false;
   String? _error;
@@ -132,9 +144,11 @@ class NewsProvider extends ChangeNotifier {
   // ── Quiz ──
 
   /// Load quiz for an article.
-  Future<void> loadQuiz(String articleId) async {
+  Future<void> loadQuiz(String articleId, {NewsArticle? article}) async {
     _isLoadingQuiz = true;
     _currentQuiz = null;
+    _currentQuizArticleId = articleId;
+    _currentQuizArticle = article ?? _findArticle(articleId);
     _answers = {};
     _quizSubmitted = false;
     notifyListeners();
@@ -158,6 +172,8 @@ class NewsProvider extends ChangeNotifier {
 
   /// Submit quiz and calculate score.
   void submitQuiz() {
+    if (_quizSubmitted) return;
+    _recordSubmittedMistakes();
     _quizSubmitted = true;
     notifyListeners();
   }
@@ -165,6 +181,8 @@ class NewsProvider extends ChangeNotifier {
   /// Reset quiz state.
   void resetQuiz() {
     _currentQuiz = null;
+    _currentQuizArticleId = null;
+    _currentQuizArticle = null;
     _answers = {};
     _quizSubmitted = false;
     notifyListeners();
@@ -186,4 +204,60 @@ class NewsProvider extends ChangeNotifier {
       return null;
     }
   }
+
+  NewsArticle? _findArticle(String articleId) {
+    for (final article in _articles) {
+      if (article.id == articleId) return article;
+    }
+    return null;
+  }
+
+  void _recordSubmittedMistakes() {
+    final quiz = _currentQuiz;
+    if (quiz == null) return;
+
+    final article = _currentQuizArticle;
+    final sourceId = article?.id ?? _currentQuizArticleId ?? 'news_quiz';
+    final sourceTitle = article?.title ?? 'News quiz';
+
+    for (final question in quiz.questions) {
+      final selectedIndex = _answers[question.id];
+      if (selectedIndex == null || selectedIndex == question.correctIndex) {
+        continue;
+      }
+
+      final selectedAnswer = _optionText(question.options, selectedIndex);
+      final correctAnswer = _optionText(
+        question.options,
+        question.correctIndex,
+      );
+
+      unawaited(
+        _mistakeRepository.saveMistake(
+          MistakeNotebookEntry(
+            id: MistakeNotebookEntry.buildId(
+              sourceType: 'news_quiz',
+              sourceId: sourceId,
+              questionId: '${question.id}:${question.question}',
+              selectedAnswer: selectedAnswer,
+            ),
+            sourceType: 'news_quiz',
+            sourceId: sourceId,
+            sourceTitle: sourceTitle,
+            question: question.question,
+            selectedAnswer: selectedAnswer,
+            correctAnswer: correctAnswer,
+            explanation: question.explanation,
+            skill: question.type.isEmpty ? 'reading' : question.type,
+            createdAt: DateTime.now(),
+          ),
+        ),
+      );
+    }
+  }
+
+  String _optionText(List<String> options, int index) {
+    if (index < 0 || index >= options.length) return '';
+    return options[index];
+  }
 }
diff --git a/flutter-app/lib/features/news/presentation/screens/news_quiz_screen.dart b/flutter-app/lib/features/news/presentation/screens/news_quiz_screen.dart
index ed38c747..338da633 100644
--- a/flutter-app/lib/features/news/presentation/screens/news_quiz_screen.dart
+++ b/flutter-app/lib/features/news/presentation/screens/news_quiz_screen.dart
@@ -38,7 +38,10 @@ class _NewsQuizScreenState extends State<NewsQuizScreen>
     )..forward();
 
     WidgetsBinding.instance.addPostFrameCallback((_) {
-      context.read<NewsProvider>().loadQuiz(widget.article.id);
+      context.read<NewsProvider>().loadQuiz(
+        widget.article.id,
+        article: widget.article,
+      );
     });
   }
 
@@ -531,7 +534,10 @@ class _NewsQuizScreenState extends State<NewsQuizScreen>
                 child: OutlinedButton.icon(
                   onPressed: () {
                     provider.resetQuiz();
-                    provider.loadQuiz(widget.article.id);
+                    provider.loadQuiz(
+                      widget.article.id,
+                      article: widget.article,
+                    );
                   },
                   icon: const Icon(Icons.refresh_rounded, size: 18),
                   label: Text('newsQuiz.retry'.tr()),
diff --git a/flutter-app/lib/features/notifications/data/datasources/notification_remote_datasource.dart b/flutter-app/lib/features/notifications/data/datasources/notification_remote_datasource.dart
index bf1ef50c..c8a65274 100644
--- a/flutter-app/lib/features/notifications/data/datasources/notification_remote_datasource.dart
+++ b/flutter-app/lib/features/notifications/data/datasources/notification_remote_datasource.dart
@@ -25,4 +25,12 @@ class NotificationRemoteDataSource {
   Future<void> markAllAsRead() async {
     await apiClient.patch('/notifications/read-all');
   }
+
+  Future<void> deleteNotification(String id) async {
+    await apiClient.delete('/notifications/$id');
+  }
+
+  Future<void> deleteAllNotifications() async {
+    await apiClient.delete('/notifications');
+  }
 }
diff --git a/flutter-app/lib/features/notifications/data/repositories/notification_repository_impl.dart b/flutter-app/lib/features/notifications/data/repositories/notification_repository_impl.dart
index 0ab8918f..4745e87e 100644
--- a/flutter-app/lib/features/notifications/data/repositories/notification_repository_impl.dart
+++ b/flutter-app/lib/features/notifications/data/repositories/notification_repository_impl.dart
@@ -96,12 +96,22 @@ class NotificationRepositoryImpl implements NotificationRepository {
   @override
   Future<void> deleteNotification(String notificationId) async {
     await _localDataSource.deleteNotification(notificationId);
+    try {
+      await _remoteDataSource?.deleteNotification(notificationId);
+    } catch (e) {
+      debugPrint('Remote delete notification failed: $e');
+    }
     await _refreshStreams();
   }
 
   @override
   Future<void> deleteAllNotifications() async {
     await _localDataSource.deleteAllNotifications();
+    try {
+      await _remoteDataSource?.deleteAllNotifications();
+    } catch (e) {
+      debugPrint('Remote delete all notifications failed: $e');
+    }
     await _refreshStreams();
   }
 
diff --git a/flutter-app/lib/features/notifications/domain/entities/notification_entity.dart b/flutter-app/lib/features/notifications/domain/entities/notification_entity.dart
index cf4d6197..ce4cb209 100644
--- a/flutter-app/lib/features/notifications/domain/entities/notification_entity.dart
+++ b/flutter-app/lib/features/notifications/domain/entities/notification_entity.dart
@@ -140,10 +140,50 @@ class NotificationEntity extends Equatable {
   }
 
   /// Get target ID from data if available
-  String? get targetId => data?['target_id'] as String?;
+  String? get targetId => _readString(data?['target_id']);
 
   /// Get route from data if available
-  String? get route => data?['route'] as String?;
+  String? get route => _readString(data?['route']);
+
+  /// Whether this notification should close back to the app root.
+  bool get opensRoot {
+    final directRoute = route;
+    if (directRoute != null) {
+      return _isRootRoute(directRoute);
+    }
+    return _readString(data?['type']) == 'starter_reward';
+  }
+
+  /// Best app route for this notification.
+  ///
+  /// Backend/FCM payloads can override this with `data.route`. If no explicit
+  /// route is provided, the app falls back to the closest existing screen.
+  String? get destinationRoute {
+    final directRoute = route;
+    if (directRoute != null && !_isRootRoute(directRoute)) {
+      return directRoute;
+    }
+
+    switch (type) {
+      case NotificationType.streakReminder:
+        return '/today-plan';
+      case NotificationType.lessonReminder:
+        return '/courses';
+      case NotificationType.vocabularyReviewReminder:
+        return '/vocabulary/review';
+      case NotificationType.achievement:
+        return '/achievements';
+      case NotificationType.newContent:
+        return '/courses';
+      case NotificationType.weeklySummary:
+        return '/profile';
+      case NotificationType.social:
+        return '/social';
+      case NotificationType.system:
+      case NotificationType.general:
+        return null;
+    }
+  }
 
   /// Factory for creating notification from FCM message
   factory NotificationEntity.fromFcm({
@@ -204,8 +244,11 @@ class NotificationEntity extends Equatable {
       case 'vocabulary_review_reminder':
         return NotificationType.vocabularyReviewReminder;
       case 'achievement':
+      case 'achievement_unlocked':
+      case 'achievements':
         return NotificationType.achievement;
       case 'new_content':
+      case 'new_content_available':
         return NotificationType.newContent;
       case 'weekly_summary':
         return NotificationType.weeklySummary;
@@ -264,6 +307,19 @@ class NotificationEntity extends Equatable {
     }
   }
 
+  static String? _readString(Object? value) {
+    if (value is! String) return null;
+    final trimmed = value.trim();
+    return trimmed.isEmpty ? null : trimmed;
+  }
+
+  static bool _isRootRoute(String route) {
+    return route == '/' ||
+        route == '/home' ||
+        route == 'home' ||
+        route == 'root';
+  }
+
   @override
   List<Object?> get props => [
     id,
diff --git a/flutter-app/lib/features/notifications/domain/services/notification_navigation_service.dart b/flutter-app/lib/features/notifications/domain/services/notification_navigation_service.dart
new file mode 100644
index 00000000..8fdd288b
--- /dev/null
+++ b/flutter-app/lib/features/notifications/domain/services/notification_navigation_service.dart
@@ -0,0 +1,30 @@
+import 'dart:async';
+
+import 'package:lexilingo_app/core/services/app_navigation_service.dart';
+import 'package:lexilingo_app/features/notifications/domain/entities/notification_entity.dart';
+
+class NotificationNavigationService {
+  const NotificationNavigationService._();
+
+  static void open(NotificationEntity notification) {
+    if (notification.opensRoot) {
+      AppNavigationService.returnToRoot();
+      return;
+    }
+
+    final route = notification.destinationRoute;
+    if (route == null) {
+      AppNavigationService.returnToRoot();
+      return;
+    }
+
+    unawaited(_openOrReturnToRoot(route));
+  }
+
+  static Future<void> _openOrReturnToRoot(String route) async {
+    final opened = await AppNavigationService.openRoute(route);
+    if (!opened) {
+      AppNavigationService.returnToRoot();
+    }
+  }
+}
diff --git a/flutter-app/lib/features/notifications/presentation/pages/notifications_page.dart b/flutter-app/lib/features/notifications/presentation/pages/notifications_page.dart
index 199b7080..cd425c10 100644
--- a/flutter-app/lib/features/notifications/presentation/pages/notifications_page.dart
+++ b/flutter-app/lib/features/notifications/presentation/pages/notifications_page.dart
@@ -2,11 +2,11 @@ import 'package:flutter/material.dart';
 import 'package:easy_localization/easy_localization.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
-import 'package:lexilingo_app/core/services/app_navigation_service.dart';
 import 'package:lexilingo_app/core/widgets/widgets.dart';
 import '../providers/notification_provider.dart';
 import '../widgets/empty_notification_widget.dart';
 import '../../domain/entities/notification_entity.dart';
+import '../../domain/services/notification_navigation_service.dart';
 
 /// Notifications Page
 /// Displays all notifications grouped by date with real-time updates
@@ -401,29 +401,7 @@ class _NotificationsPageState extends State<NotificationsPage> {
       provider.markAsRead(notification.id);
     }
 
-    // Navigate based on notification type
-    final route = notification.route;
-    if (route != null && route == '/vocabulary/review') {
-      AppNavigationService.openRoute(route);
-      return;
-    }
-
-    switch (notification.type) {
-      case NotificationType.streakReminder:
-      case NotificationType.lessonReminder:
-      case NotificationType.vocabularyReviewReminder:
-        // Could navigate to home or learning screen
-        break;
-      case NotificationType.achievement:
-        // Could navigate to achievements screen
-        break;
-      case NotificationType.newContent:
-        // Could navigate to courses screen
-        break;
-      default:
-        // Just mark as read
-        break;
-    }
+    NotificationNavigationService.open(notification);
   }
 
   IconData _getIconData(String? identifier) {
diff --git a/flutter-app/lib/features/offline/presentation/pages/offline_sync_center_page.dart b/flutter-app/lib/features/offline/presentation/pages/offline_sync_center_page.dart
new file mode 100644
index 00000000..cf90495a
--- /dev/null
+++ b/flutter-app/lib/features/offline/presentation/pages/offline_sync_center_page.dart
@@ -0,0 +1,576 @@
+import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/services/background_sync_queue_service.dart';
+import 'package:lexilingo_app/core/services/local_cache_service.dart';
+import 'package:lexilingo_app/core/services/user_scope_service.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+class OfflineSyncCenterPage extends StatefulWidget {
+  const OfflineSyncCenterPage({super.key});
+
+  @override
+  State<OfflineSyncCenterPage> createState() => _OfflineSyncCenterPageState();
+}
+
+class _OfflineSyncCenterPageState extends State<OfflineSyncCenterPage> {
+  final Connectivity _connectivity = Connectivity();
+  final LocalCacheService _cacheService = LocalCacheService.instance;
+  final BackgroundSyncQueueService _queueService =
+      BackgroundSyncQueueService.instance;
+
+  OfflineSyncSnapshot? _snapshot;
+  String? _errorMessage;
+  bool _isLoading = true;
+  bool _isMutating = false;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _loadSnapshot();
+    });
+  }
+
+  Future<void> _loadSnapshot() async {
+    setState(() {
+      _isLoading = true;
+      _errorMessage = null;
+    });
+
+    try {
+      final connectivityResults = await _connectivity.checkConnectivity();
+      final isOnline = connectivityResults.any(
+        (result) => result != ConnectivityResult.none,
+      );
+      final cacheSize = await _cacheService.getCacheSize();
+      final cacheCountsByType = await _cacheService.getCacheCountsByType();
+      final userScope = await UserScopeService.getActiveUserId();
+      final queueSummary = userScope == null || userScope.isEmpty
+          ? SyncQueueSummary.unsupported
+          : await _queueService.getSummary(userScope: userScope);
+
+      if (!mounted) return;
+      setState(() {
+        _snapshot = OfflineSyncSnapshot(
+          isOnline: isOnline,
+          cacheSize: cacheSize,
+          cacheCountsByType: cacheCountsByType,
+          activeUserScope: userScope,
+          queueSummary: queueSummary,
+        );
+        _isLoading = false;
+      });
+    } catch (e) {
+      if (!mounted) return;
+      setState(() {
+        _errorMessage = e.toString();
+        _isLoading = false;
+      });
+    }
+  }
+
+  Future<void> _clearExpiredCache() async {
+    setState(() => _isMutating = true);
+    try {
+      final cleared = await _cacheService.clearExpired();
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text(
+            'offlineSync.expiredCleared'.tr(namedArgs: {'count': '$cleared'}),
+          ),
+        ),
+      );
+      await _loadSnapshot();
+    } finally {
+      if (mounted) setState(() => _isMutating = false);
+    }
+  }
+
+  Future<void> _confirmClearAllCache() async {
+    final confirmed = await showDialog<bool>(
+      context: context,
+      builder: (context) {
+        return AlertDialog(
+          title: Text('offlineSync.clearAllTitle'.tr()),
+          content: Text('offlineSync.clearAllMessage'.tr()),
+          actions: [
+            TextButton(
+              onPressed: () => Navigator.pop(context, false),
+              child: Text('common.cancel'.tr()),
+            ),
+            FilledButton(
+              onPressed: () => Navigator.pop(context, true),
+              child: Text('offlineSync.clearAllConfirm'.tr()),
+            ),
+          ],
+        );
+      },
+    );
+
+    if (confirmed != true) return;
+
+    setState(() => _isMutating = true);
+    try {
+      await _cacheService.clearAll();
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text('offlineSync.allCacheCleared'.tr())),
+      );
+      await _loadSnapshot();
+    } finally {
+      if (mounted) setState(() => _isMutating = false);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Scaffold(
+      backgroundColor: isDark
+          ? AppColors.backgroundDark
+          : AppColors.backgroundLight,
+      appBar: AppBar(
+        title: Text('offlineSync.title'.tr()),
+        actions: [
+          IconButton(
+            tooltip: 'common.refresh'.tr(),
+            onPressed: _isLoading || _isMutating ? null : _loadSnapshot,
+            icon: const Icon(Icons.refresh_rounded),
+          ),
+        ],
+      ),
+      body: SafeArea(
+        child: _isLoading && _snapshot == null
+            ? const Center(child: CircularProgressIndicator())
+            : _errorMessage != null && _snapshot == null
+            ? _ErrorState(message: _errorMessage!, onRetry: _loadSnapshot)
+            : RefreshIndicator(
+                onRefresh: _loadSnapshot,
+                child: ListView(
+                  physics: const AlwaysScrollableScrollPhysics(),
+                  padding: const EdgeInsets.fromLTRB(16, 12, 16, 24),
+                  children: [
+                    _ConnectionCard(snapshot: _snapshot!),
+                    const SizedBox(height: 14),
+                    _CacheCard(
+                      snapshot: _snapshot!,
+                      isMutating: _isMutating,
+                      onClearExpired: _clearExpiredCache,
+                      onClearAll: _confirmClearAllCache,
+                    ),
+                    const SizedBox(height: 14),
+                    _QueueCard(snapshot: _snapshot!),
+                  ],
+                ),
+              ),
+      ),
+    );
+  }
+}
+
+class OfflineSyncSnapshot {
+  const OfflineSyncSnapshot({
+    required this.isOnline,
+    required this.cacheSize,
+    required this.cacheCountsByType,
+    required this.activeUserScope,
+    required this.queueSummary,
+  });
+
+  final bool isOnline;
+  final int cacheSize;
+  final Map<String, int> cacheCountsByType;
+  final String? activeUserScope;
+  final SyncQueueSummary queueSummary;
+
+  bool get hasActiveUser =>
+      activeUserScope != null && activeUserScope!.isNotEmpty;
+}
+
+class _ConnectionCard extends StatelessWidget {
+  const _ConnectionCard({required this.snapshot});
+
+  final OfflineSyncSnapshot snapshot;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final color = snapshot.isOnline
+        ? AppColors.greenSuccess
+        : AppColors.warning;
+
+    return _Panel(
+      child: Row(
+        children: [
+          _IconBadge(
+            icon: snapshot.isOnline
+                ? Icons.wifi_rounded
+                : Icons.wifi_off_rounded,
+            color: color,
+          ),
+          const SizedBox(width: 14),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  snapshot.isOnline
+                      ? 'offlineSync.onlineTitle'.tr()
+                      : 'offlineSync.offlineTitle'.tr(),
+                  style: Theme.of(context).textTheme.titleMedium?.copyWith(
+                    fontWeight: FontWeight.w900,
+                  ),
+                ),
+                const SizedBox(height: 4),
+                Text(
+                  snapshot.isOnline
+                      ? 'offlineSync.onlineSubtitle'.tr()
+                      : 'offlineSync.offlineSubtitle'.tr(),
+                  style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                    color: AppColorRoles.textSecondary(isDark),
+                    height: 1.3,
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _CacheCard extends StatelessWidget {
+  const _CacheCard({
+    required this.snapshot,
+    required this.isMutating,
+    required this.onClearExpired,
+    required this.onClearAll,
+  });
+
+  final OfflineSyncSnapshot snapshot;
+  final bool isMutating;
+  final VoidCallback onClearExpired;
+  final VoidCallback onClearAll;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final entries = snapshot.cacheCountsByType.entries.toList()
+      ..sort((a, b) => a.key.compareTo(b.key));
+
+    return _Panel(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          _PanelTitle(
+            icon: Icons.storage_rounded,
+            color: AppColorRoles.primary(isDark),
+            title: 'offlineSync.cacheTitle'.tr(),
+            subtitle: 'offlineSync.cacheSubtitle'.tr(),
+          ),
+          const SizedBox(height: 14),
+          _MetricRow(
+            label: 'offlineSync.totalEntries'.tr(),
+            value: '${snapshot.cacheSize}',
+          ),
+          const SizedBox(height: 10),
+          if (entries.isEmpty)
+            _EmptyLine(text: 'offlineSync.noCache'.tr())
+          else
+            for (final entry in entries)
+              _MetricRow(
+                label: _cacheTypeLabel(entry.key),
+                value: '${entry.value}',
+              ),
+          const SizedBox(height: 16),
+          Row(
+            children: [
+              Expanded(
+                child: OutlinedButton.icon(
+                  onPressed: isMutating ? null : onClearExpired,
+                  icon: const Icon(Icons.cleaning_services_rounded),
+                  label: Text('offlineSync.clearExpired'.tr()),
+                ),
+              ),
+              const SizedBox(width: 10),
+              Expanded(
+                child: FilledButton.icon(
+                  onPressed: isMutating ? null : onClearAll,
+                  icon: isMutating
+                      ? const SizedBox.square(
+                          dimension: 16,
+                          child: CircularProgressIndicator(strokeWidth: 2),
+                        )
+                      : const Icon(Icons.delete_sweep_rounded),
+                  label: Text('offlineSync.clearAll'.tr()),
+                ),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+
+  String _cacheTypeLabel(String type) {
+    final key = 'offlineSync.cacheTypes.$type';
+    final translated = key.tr();
+    return translated == key ? type : translated;
+  }
+}
+
+class _QueueCard extends StatelessWidget {
+  const _QueueCard({required this.snapshot});
+
+  final OfflineSyncSnapshot snapshot;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final summary = snapshot.queueSummary;
+
+    return _Panel(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          _PanelTitle(
+            icon: Icons.sync_rounded,
+            color: AppColors.teal,
+            title: 'offlineSync.queueTitle'.tr(),
+            subtitle: 'offlineSync.queueSubtitle'.tr(),
+          ),
+          const SizedBox(height: 14),
+          if (!snapshot.hasActiveUser)
+            _EmptyLine(text: 'offlineSync.noUserScope'.tr())
+          else if (!summary.persistentQueueAvailable)
+            _EmptyLine(text: 'offlineSync.queueUnavailable'.tr())
+          else ...[
+            _MetricRow(
+              label: 'offlineSync.totalQueued'.tr(),
+              value: '${summary.totalCount}',
+            ),
+            _MetricRow(
+              label: 'offlineSync.readyQueued'.tr(),
+              value: '${summary.readyCount}',
+            ),
+            _MetricRow(
+              label: 'offlineSync.scheduledQueued'.tr(),
+              value: '${summary.scheduledCount}',
+            ),
+            _MetricRow(
+              label: 'offlineSync.retryingQueued'.tr(),
+              value: '${summary.retryingCount}',
+            ),
+          ],
+          const SizedBox(height: 10),
+          Text(
+            'offlineSync.queueHint'.tr(),
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: AppColorRoles.textSecondary(isDark),
+              height: 1.35,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _Panel extends StatelessWidget {
+  const _Panel({required this.child});
+
+  final Widget child;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(
+          color: isDark ? AppColors.borderDarkSoft : AppColors.slate200,
+        ),
+      ),
+      child: child,
+    );
+  }
+}
+
+class _PanelTitle extends StatelessWidget {
+  const _PanelTitle({
+    required this.icon,
+    required this.color,
+    required this.title,
+    required this.subtitle,
+  });
+
+  final IconData icon;
+  final Color color;
+  final String title;
+  final String subtitle;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Row(
+      children: [
+        _IconBadge(icon: icon, color: color),
+        const SizedBox(width: 12),
+        Expanded(
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Text(
+                title,
+                style: Theme.of(
+                  context,
+                ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w900),
+              ),
+              const SizedBox(height: 3),
+              Text(
+                subtitle,
+                style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                  color: AppColorRoles.textSecondary(isDark),
+                  height: 1.3,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _IconBadge extends StatelessWidget {
+  const _IconBadge({required this.icon, required this.color});
+
+  final IconData icon;
+  final Color color;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      width: 44,
+      height: 44,
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: isDark ? 0.18 : 0.12),
+        borderRadius: BorderRadius.circular(13),
+      ),
+      child: Icon(icon, color: color, size: 23),
+    );
+  }
+}
+
+class _MetricRow extends StatelessWidget {
+  const _MetricRow({required this.label, required this.value});
+
+  final String label;
+  final String value;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 5),
+      child: Row(
+        children: [
+          Expanded(
+            child: Text(
+              label,
+              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: AppColorRoles.textSecondary(isDark),
+              ),
+            ),
+          ),
+          Text(
+            value,
+            style: Theme.of(
+              context,
+            ).textTheme.bodyMedium?.copyWith(fontWeight: FontWeight.w900),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _EmptyLine extends StatelessWidget {
+  const _EmptyLine({required this.text});
+
+  final String text;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Text(
+      text,
+      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+        color: AppColorRoles.textSecondary(isDark),
+        height: 1.35,
+      ),
+    );
+  }
+}
+
+class _ErrorState extends StatelessWidget {
+  const _ErrorState({required this.message, required this.onRetry});
+
+  final String message;
+  final VoidCallback onRetry;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(24),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(
+              Icons.error_outline_rounded,
+              color: Theme.of(context).colorScheme.error,
+              size: 42,
+            ),
+            const SizedBox(height: 12),
+            Text(
+              'offlineSync.loadFailed'.tr(),
+              textAlign: TextAlign.center,
+              style: Theme.of(
+                context,
+              ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.w900),
+            ),
+            const SizedBox(height: 8),
+            Text(
+              message,
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: AppColorRoles.textSecondary(isDark),
+              ),
+            ),
+            const SizedBox(height: 16),
+            FilledButton.icon(
+              onPressed: onRetry,
+              icon: const Icon(Icons.refresh_rounded),
+              label: Text('common.retry'.tr()),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/podcast/data/repositories/podcast_repository.dart b/flutter-app/lib/features/podcast/data/repositories/podcast_repository.dart
index 68b590e7..ff268861 100644
--- a/flutter-app/lib/features/podcast/data/repositories/podcast_repository.dart
+++ b/flutter-app/lib/features/podcast/data/repositories/podcast_repository.dart
@@ -144,6 +144,34 @@ class PodcastRepository {
         .toList();
   }
 
+  /// Generate or load a cached learner transcript for [episode].
+  Future<String?> generateTranscript(PodcastEpisode episode) async {
+    final cacheKey = 'podcast:transcript:${episode.guid}';
+
+    final data = await _cache.getOrFetch(
+      key: cacheKey,
+      type: 'podcast',
+      fetchFn: () async {
+        final uri = Uri.parse('$_baseUrl/transcript');
+        final response = await _client.post(
+          uri,
+          headers: const {'Content-Type': 'application/json'},
+          body: jsonEncode({
+            'feed_url': episode.feedUrl,
+            'episode_guid': episode.guid,
+            'audio_url': episode.audioUrl,
+          }),
+        );
+        _checkResponse(response, uri);
+        return jsonDecode(response.body) as Map<String, dynamic>;
+      },
+    );
+
+    final transcript = data?['transcript'] as String?;
+    if (transcript == null || transcript.trim().isEmpty) return null;
+    return transcript.trim();
+  }
+
   // ──── Listening History (SQLite via LocalCacheService) ────
 
   /// Get listening history for a specific episode from local SQLite cache.
diff --git a/flutter-app/lib/features/podcast/presentation/screens/podcast_player_screen.dart b/flutter-app/lib/features/podcast/presentation/screens/podcast_player_screen.dart
index f931bfa8..70c8f242 100644
--- a/flutter-app/lib/features/podcast/presentation/screens/podcast_player_screen.dart
+++ b/flutter-app/lib/features/podcast/presentation/screens/podcast_player_screen.dart
@@ -6,6 +6,7 @@ import '../../../../core/services/podcast_audio_handler.dart';
 import '../../../../core/theme/app_theme.dart';
 import '../../../../core/widgets/lottie_loading_widget.dart';
 import '../../../games/data/repositories/games_repository.dart';
+import '../../data/repositories/podcast_repository.dart';
 import '../../domain/entities/podcast_entities.dart';
 import '../widgets/audio_player_controls.dart';
 import '../widgets/transcript_panel.dart';
@@ -36,6 +37,7 @@ class PodcastPlayerScreen extends StatefulWidget {
 
 class _PodcastPlayerScreenState extends State<PodcastPlayerScreen> {
   PodcastAudioHandler? _handler;
+  final PodcastRepository _podcastRepository = PodcastRepository();
 
   Duration _position = Duration.zero;
   Duration _duration = Duration.zero;
@@ -379,9 +381,14 @@ class _PodcastPlayerScreenState extends State<PodcastPlayerScreen> {
   Future<void> _generateTranscript() async {
     setState(() => _transcriptLoading = true);
     try {
-      // Placeholder: real implementation would call AI service.
-      await Future<void>.delayed(const Duration(seconds: 1));
-      setState(() => _transcript = null);
+      final transcript = await _podcastRepository.generateTranscript(
+        widget.episode,
+      );
+      if (!mounted) return;
+      setState(() => _transcript = transcript);
+    } catch (e) {
+      debugPrint('PodcastPlayerScreen: failed to generate transcript: $e');
+      if (mounted) setState(() => _transcript = null);
     } finally {
       if (mounted) setState(() => _transcriptLoading = false);
     }
diff --git a/flutter-app/lib/features/practice/presentation/pages/practice_lab_page.dart b/flutter-app/lib/features/practice/presentation/pages/practice_lab_page.dart
new file mode 100644
index 00000000..1da244cc
--- /dev/null
+++ b/flutter-app/lib/features/practice/presentation/pages/practice_lab_page.dart
@@ -0,0 +1,557 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/premium_gate.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/proficiency_provider.dart';
+import 'package:lexilingo_app/features/practice/presentation/widgets/practice_lab_models.dart';
+import 'package:lexilingo_app/features/practice/presentation/widgets/practice_lab_navigation.dart';
+import 'package:provider/provider.dart';
+
+class PracticeLabPage extends StatefulWidget {
+  const PracticeLabPage({super.key});
+
+  @override
+  State<PracticeLabPage> createState() => _PracticeLabPageState();
+}
+
+class _PracticeLabPageState extends State<PracticeLabPage> {
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      context.read<ProficiencyProvider>().loadProfile();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Scaffold(
+      backgroundColor: isDark
+          ? AppColors.backgroundDark
+          : AppColors.backgroundLight,
+      appBar: AppBar(title: Text('practiceLab.title'.tr())),
+      body: SafeArea(
+        child: Consumer<ProficiencyProvider>(
+          builder: (context, proficiency, _) {
+            final items = buildPracticeLabItems(
+              weakestSkills: proficiency.weakestSkills,
+            );
+            final recommended = recommendedPracticeItems(items: items);
+            final hasRecommendations = items.any((item) => item.recommended);
+
+            return RefreshIndicator(
+              onRefresh: proficiency.loadProfile,
+              child: ListView(
+                physics: const AlwaysScrollableScrollPhysics(),
+                padding: const EdgeInsets.fromLTRB(16, 12, 16, 24),
+                children: [
+                  _PracticeLabHero(
+                    levelCode: proficiency.levelCode,
+                    recommendedCount: hasRecommendations
+                        ? recommended.length
+                        : 0,
+                    isLoading: proficiency.isLoading,
+                  ),
+                  const SizedBox(height: 16),
+                  _SectionHeader(
+                    title: 'practiceLab.recommendedTitle'.tr(),
+                    subtitle: hasRecommendations
+                        ? 'practiceLab.recommendedSubtitle'.tr()
+                        : 'practiceLab.fallbackSubtitle'.tr(),
+                  ),
+                  const SizedBox(height: 10),
+                  for (final item in recommended) ...[
+                    _PracticeLabCardGate(
+                      item: item,
+                      compact: true,
+                      onTap: () => openPracticeLabItem(context, item),
+                    ),
+                    const SizedBox(height: 10),
+                  ],
+                  const SizedBox(height: 8),
+                  _SectionHeader(
+                    title: 'practiceLab.allSkillsTitle'.tr(),
+                    subtitle: 'practiceLab.allSkillsSubtitle'.tr(),
+                  ),
+                  const SizedBox(height: 10),
+                  for (final item in items) ...[
+                    _PracticeLabCardGate(
+                      item: item,
+                      onTap: () => openPracticeLabItem(context, item),
+                    ),
+                    const SizedBox(height: 10),
+                  ],
+                ],
+              ),
+            );
+          },
+        ),
+      ),
+    );
+  }
+}
+
+class _PracticeLabCardGate extends StatelessWidget {
+  const _PracticeLabCardGate({
+    required this.item,
+    required this.onTap,
+    this.compact = false,
+  });
+
+  final PracticeLabItem item;
+  final VoidCallback onTap;
+  final bool compact;
+
+  @override
+  Widget build(BuildContext context) {
+    final card = _PracticeLabSkillCard(
+      item: item,
+      compact: compact,
+      onTap: onTap,
+    );
+
+    if (!item.premiumOnly) return card;
+
+    return PremiumGate(
+      lockedChild: _LockedPracticeLabCard(item: item, compact: compact),
+      child: card,
+    );
+  }
+}
+
+class _PracticeLabHero extends StatelessWidget {
+  const _PracticeLabHero({
+    required this.levelCode,
+    required this.recommendedCount,
+    required this.isLoading,
+  });
+
+  final String levelCode;
+  final int recommendedCount;
+  final bool isLoading;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+
+    return Container(
+      padding: const EdgeInsets.all(18),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+        borderRadius: BorderRadius.circular(18),
+        border: Border.all(
+          color: isDark ? AppColors.borderDarkSoft : AppColors.slate200,
+        ),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Container(
+                width: 48,
+                height: 48,
+                decoration: BoxDecoration(
+                  color: accent.withValues(alpha: isDark ? 0.2 : 0.12),
+                  borderRadius: BorderRadius.circular(14),
+                ),
+                child: Icon(Icons.science_rounded, color: accent, size: 26),
+              ),
+              const SizedBox(width: 14),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      'practiceLab.heroTitle'.tr(),
+                      style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                        fontWeight: FontWeight.w900,
+                      ),
+                    ),
+                    const SizedBox(height: 4),
+                    Text(
+                      'practiceLab.heroSubtitle'.tr(),
+                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                        color: AppColorRoles.textSecondary(isDark),
+                        height: 1.35,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 16),
+          Row(
+            children: [
+              Expanded(
+                child: _HeroMetric(
+                  label: 'practiceLab.currentLevel'.tr(),
+                  value: levelCode,
+                ),
+              ),
+              const SizedBox(width: 10),
+              Expanded(
+                child: _HeroMetric(
+                  label: 'practiceLab.recommended'.tr(),
+                  value: isLoading ? '...' : '$recommendedCount',
+                ),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _HeroMetric extends StatelessWidget {
+  const _HeroMetric({required this.label, required this.value});
+
+  final String label;
+  final String value;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 12),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkInput : AppColors.grey50,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            value,
+            maxLines: 1,
+            overflow: TextOverflow.ellipsis,
+            style: Theme.of(
+              context,
+            ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w900),
+          ),
+          const SizedBox(height: 3),
+          Text(
+            label,
+            maxLines: 1,
+            overflow: TextOverflow.ellipsis,
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: AppColorRoles.textSecondary(isDark),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _SectionHeader extends StatelessWidget {
+  const _SectionHeader({required this.title, required this.subtitle});
+
+  final String title;
+  final String subtitle;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Text(
+          title,
+          style: Theme.of(
+            context,
+          ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w900),
+        ),
+        const SizedBox(height: 3),
+        Text(
+          subtitle,
+          style: Theme.of(context).textTheme.bodySmall?.copyWith(
+            color: AppColorRoles.textSecondary(isDark),
+            height: 1.3,
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _PracticeLabSkillCard extends StatelessWidget {
+  const _PracticeLabSkillCard({
+    required this.item,
+    required this.onTap,
+    this.compact = false,
+  });
+
+  final PracticeLabItem item;
+  final VoidCallback onTap;
+  final bool compact;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final surface = isDark ? AppColors.surfaceDarkMuted : Colors.white;
+    final borderColor = item.recommended
+        ? item.color.withValues(alpha: isDark ? 0.65 : 0.45)
+        : isDark
+        ? AppColors.borderDarkSoft
+        : AppColors.slate200;
+
+    return Material(
+      color: surface,
+      borderRadius: BorderRadius.circular(16),
+      child: InkWell(
+        onTap: onTap,
+        borderRadius: BorderRadius.circular(16),
+        child: Container(
+          padding: EdgeInsets.all(compact ? 14 : 16),
+          decoration: BoxDecoration(
+            borderRadius: BorderRadius.circular(16),
+            border: Border.all(color: borderColor),
+          ),
+          child: Row(
+            crossAxisAlignment: CrossAxisAlignment.center,
+            children: [
+              Container(
+                width: compact ? 44 : 50,
+                height: compact ? 44 : 50,
+                decoration: BoxDecoration(
+                  color: item.color.withValues(alpha: isDark ? 0.2 : 0.12),
+                  borderRadius: BorderRadius.circular(14),
+                ),
+                child: Icon(
+                  item.icon,
+                  color: item.color,
+                  size: compact ? 22 : 25,
+                ),
+              ),
+              const SizedBox(width: 14),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Row(
+                      children: [
+                        Expanded(
+                          child: Text(
+                            item.titleKey.tr(),
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis,
+                            style: Theme.of(context).textTheme.titleMedium
+                                ?.copyWith(fontWeight: FontWeight.w900),
+                          ),
+                        ),
+                        if (item.recommended) ...[
+                          const SizedBox(width: 8),
+                          _RecommendedPill(color: item.color),
+                        ],
+                      ],
+                    ),
+                    const SizedBox(height: 5),
+                    Text(
+                      item.subtitleKey.tr(),
+                      maxLines: compact ? 1 : 2,
+                      overflow: TextOverflow.ellipsis,
+                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                        color: AppColorRoles.textSecondary(isDark),
+                        height: 1.3,
+                      ),
+                    ),
+                    const SizedBox(height: 10),
+                    Wrap(
+                      spacing: 8,
+                      runSpacing: 6,
+                      crossAxisAlignment: WrapCrossAlignment.center,
+                      children: [
+                        _SmallChip(
+                          icon: Icons.schedule_rounded,
+                          label: item.estimateKey.tr(),
+                        ),
+                        _SmallChip(
+                          icon: Icons.play_arrow_rounded,
+                          label: item.actionKey.tr(),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+              const SizedBox(width: 10),
+              Icon(
+                Icons.chevron_right_rounded,
+                color: AppColorRoles.textSecondary(isDark),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _LockedPracticeLabCard extends StatelessWidget {
+  const _LockedPracticeLabCard({required this.item, required this.compact});
+
+  final PracticeLabItem item;
+  final bool compact;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final surface = isDark ? AppColors.surfaceDarkMuted : Colors.white;
+
+    return Container(
+      padding: EdgeInsets.all(compact ? 14 : 16),
+      decoration: BoxDecoration(
+        color: surface,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(
+          color: AppColors.gold.withValues(alpha: isDark ? 0.65 : 0.5),
+        ),
+      ),
+      child: Row(
+        children: [
+          Container(
+            width: compact ? 44 : 50,
+            height: compact ? 44 : 50,
+            decoration: BoxDecoration(
+              color: AppColors.gold.withValues(alpha: isDark ? 0.18 : 0.14),
+              borderRadius: BorderRadius.circular(14),
+            ),
+            child: const Icon(
+              Icons.workspace_premium_rounded,
+              color: AppColors.goldDark,
+              size: 25,
+            ),
+          ),
+          const SizedBox(width: 14),
+          Expanded(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Row(
+                  children: [
+                    Expanded(
+                      child: Text(
+                        item.titleKey.tr(),
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                        style: Theme.of(context).textTheme.titleMedium
+                            ?.copyWith(fontWeight: FontWeight.w900),
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    Container(
+                      padding: const EdgeInsets.symmetric(
+                        horizontal: 8,
+                        vertical: 4,
+                      ),
+                      decoration: BoxDecoration(
+                        color: AppColors.gold.withValues(alpha: 0.15),
+                        borderRadius: BorderRadius.circular(999),
+                      ),
+                      child: Text(
+                        'practiceLab.premiumOnly'.tr(),
+                        style: const TextStyle(
+                          color: AppColors.goldDark,
+                          fontWeight: FontWeight.w900,
+                          fontSize: 11,
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+                const SizedBox(height: 5),
+                Text(
+                  'practiceLab.premiumLockedSubtitle'.tr(),
+                  maxLines: compact ? 1 : 2,
+                  overflow: TextOverflow.ellipsis,
+                  style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                    color: AppColorRoles.textSecondary(isDark),
+                    height: 1.3,
+                  ),
+                ),
+                const SizedBox(height: 10),
+                _SmallChip(
+                  icon: Icons.lock_open_rounded,
+                  label: 'practiceLab.unlockPremium'.tr(),
+                ),
+              ],
+            ),
+          ),
+          const SizedBox(width: 10),
+          Icon(
+            Icons.chevron_right_rounded,
+            color: AppColorRoles.textSecondary(isDark),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _RecommendedPill extends StatelessWidget {
+  const _RecommendedPill({required this.color});
+
+  final Color color;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: 0.12),
+        borderRadius: BorderRadius.circular(999),
+      ),
+      child: Text(
+        'practiceLab.focus'.tr(),
+        style: TextStyle(
+          color: color,
+          fontWeight: FontWeight.w900,
+          fontSize: 11,
+        ),
+      ),
+    );
+  }
+}
+
+class _SmallChip extends StatelessWidget {
+  const _SmallChip({required this.icon, required this.label});
+
+  final IconData icon;
+  final String label;
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 5),
+      decoration: BoxDecoration(
+        color: isDark ? AppColors.surfaceDarkInput : AppColors.grey100,
+        borderRadius: BorderRadius.circular(8),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(icon, size: 13, color: AppColorRoles.textSecondary(isDark)),
+          const SizedBox(width: 5),
+          Text(
+            label,
+            style: Theme.of(context).textTheme.labelSmall?.copyWith(
+              color: AppColorRoles.textSecondary(isDark),
+              fontWeight: FontWeight.w800,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/practice/presentation/widgets/practice_lab_models.dart b/flutter-app/lib/features/practice/presentation/widgets/practice_lab_models.dart
new file mode 100644
index 00000000..d8e6c85b
--- /dev/null
+++ b/flutter-app/lib/features/practice/presentation/widgets/practice_lab_models.dart
@@ -0,0 +1,152 @@
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/features/level/domain/entities/proficiency_entity.dart';
+
+enum PracticeLabDestination {
+  vocabularyReview,
+  voicePractice,
+  podcast,
+  news,
+  games,
+  lexi,
+  mistakeNotebook,
+}
+
+class PracticeLabItem {
+  final SkillType skill;
+  final String titleKey;
+  final String subtitleKey;
+  final String actionKey;
+  final String estimateKey;
+  final IconData icon;
+  final Color color;
+  final PracticeLabDestination destination;
+  final bool recommended;
+  final bool premiumOnly;
+
+  const PracticeLabItem({
+    required this.skill,
+    required this.titleKey,
+    required this.subtitleKey,
+    required this.actionKey,
+    required this.estimateKey,
+    required this.icon,
+    required this.color,
+    required this.destination,
+    this.recommended = false,
+    this.premiumOnly = false,
+  });
+
+  PracticeLabItem copyWith({bool? recommended}) {
+    return PracticeLabItem(
+      skill: skill,
+      titleKey: titleKey,
+      subtitleKey: subtitleKey,
+      actionKey: actionKey,
+      estimateKey: estimateKey,
+      icon: icon,
+      color: color,
+      destination: destination,
+      recommended: recommended ?? this.recommended,
+      premiumOnly: premiumOnly,
+    );
+  }
+}
+
+List<PracticeLabItem> buildPracticeLabItems({
+  List<SkillScore> weakestSkills = const [],
+}) {
+  final weakSkillSet = weakestSkills.map((score) => score.skill).toSet();
+
+  return _basePracticeLabItems
+      .map(
+        (item) => item.copyWith(recommended: weakSkillSet.contains(item.skill)),
+      )
+      .toList(growable: false);
+}
+
+List<PracticeLabItem> recommendedPracticeItems({
+  required List<PracticeLabItem> items,
+  int limit = 2,
+}) {
+  final recommended = items.where((item) => item.recommended).toList();
+  if (recommended.isNotEmpty) {
+    return recommended.take(limit).toList(growable: false);
+  }
+
+  return items.take(limit).toList(growable: false);
+}
+
+const List<PracticeLabItem> _basePracticeLabItems = [
+  PracticeLabItem(
+    skill: SkillType.vocabulary,
+    titleKey: 'practiceLab.skills.vocabulary.title',
+    subtitleKey: 'practiceLab.skills.vocabulary.subtitle',
+    actionKey: 'practiceLab.skills.vocabulary.action',
+    estimateKey: 'practiceLab.skills.vocabulary.estimate',
+    icon: Icons.style_rounded,
+    color: AppColors.orange,
+    destination: PracticeLabDestination.vocabularyReview,
+  ),
+  PracticeLabItem(
+    skill: SkillType.speaking,
+    titleKey: 'practiceLab.skills.speaking.title',
+    subtitleKey: 'practiceLab.skills.speaking.subtitle',
+    actionKey: 'practiceLab.skills.speaking.action',
+    estimateKey: 'practiceLab.skills.speaking.estimate',
+    icon: Icons.mic_rounded,
+    color: AppColors.greenSuccessBright,
+    destination: PracticeLabDestination.voicePractice,
+  ),
+  PracticeLabItem(
+    skill: SkillType.listening,
+    titleKey: 'practiceLab.skills.listening.title',
+    subtitleKey: 'practiceLab.skills.listening.subtitle',
+    actionKey: 'practiceLab.skills.listening.action',
+    estimateKey: 'practiceLab.skills.listening.estimate',
+    icon: Icons.headphones_rounded,
+    color: AppColors.teal,
+    destination: PracticeLabDestination.podcast,
+  ),
+  PracticeLabItem(
+    skill: SkillType.reading,
+    titleKey: 'practiceLab.skills.reading.title',
+    subtitleKey: 'practiceLab.skills.reading.subtitle',
+    actionKey: 'practiceLab.skills.reading.action',
+    estimateKey: 'practiceLab.skills.reading.estimate',
+    icon: Icons.menu_book_rounded,
+    color: AppColors.primary,
+    destination: PracticeLabDestination.news,
+  ),
+  PracticeLabItem(
+    skill: SkillType.grammar,
+    titleKey: 'practiceLab.skills.grammar.title',
+    subtitleKey: 'practiceLab.skills.grammar.subtitle',
+    actionKey: 'practiceLab.skills.grammar.action',
+    estimateKey: 'practiceLab.skills.grammar.estimate',
+    icon: Icons.edit_note_rounded,
+    color: AppColors.purple,
+    destination: PracticeLabDestination.games,
+  ),
+  PracticeLabItem(
+    skill: SkillType.reading,
+    titleKey: 'practiceLab.skills.mistakes.title',
+    subtitleKey: 'practiceLab.skills.mistakes.subtitle',
+    actionKey: 'practiceLab.skills.mistakes.action',
+    estimateKey: 'practiceLab.skills.mistakes.estimate',
+    icon: Icons.rule_folder_rounded,
+    color: AppColors.errorBright,
+    destination: PracticeLabDestination.mistakeNotebook,
+  ),
+  PracticeLabItem(
+    skill: SkillType.writing,
+    titleKey: 'practiceLab.skills.writing.title',
+    subtitleKey: 'practiceLab.skills.writing.subtitle',
+    actionKey: 'practiceLab.skills.writing.action',
+    estimateKey: 'practiceLab.skills.writing.estimate',
+    icon: Icons.drive_file_rename_outline_rounded,
+    color: AppColors.deepOrange,
+    destination: PracticeLabDestination.lexi,
+    premiumOnly: true,
+  ),
+];
diff --git a/flutter-app/lib/features/practice/presentation/widgets/practice_lab_navigation.dart b/flutter-app/lib/features/practice/presentation/widgets/practice_lab_navigation.dart
new file mode 100644
index 00000000..d680583d
--- /dev/null
+++ b/flutter-app/lib/features/practice/presentation/widgets/practice_lab_navigation.dart
@@ -0,0 +1,31 @@
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/features/practice/presentation/widgets/practice_lab_models.dart';
+import 'package:lexilingo_app/features/voice/presentation/screens/voice_practice_screen.dart';
+
+void openPracticeLabItem(BuildContext context, PracticeLabItem item) {
+  switch (item.destination) {
+    case PracticeLabDestination.vocabularyReview:
+      Navigator.of(context).pushNamed('/vocabulary/review');
+      break;
+    case PracticeLabDestination.voicePractice:
+      Navigator.of(
+        context,
+      ).push(MaterialPageRoute(builder: (_) => const VoicePracticeScreen()));
+      break;
+    case PracticeLabDestination.podcast:
+      Navigator.of(context).pushNamed('/podcast');
+      break;
+    case PracticeLabDestination.news:
+      Navigator.of(context).pushNamed('/news');
+      break;
+    case PracticeLabDestination.games:
+      Navigator.of(context).pushNamed('/games');
+      break;
+    case PracticeLabDestination.lexi:
+      Navigator.of(context).pushNamed('/lexi');
+      break;
+    case PracticeLabDestination.mistakeNotebook:
+      Navigator.of(context).pushNamed('/mistake-notebook');
+      break;
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/pages/profile_page.dart b/flutter-app/lib/features/profile/presentation/pages/profile_page.dart
index a540b1bf..0d80b58e 100644
--- a/flutter-app/lib/features/profile/presentation/pages/profile_page.dart
+++ b/flutter-app/lib/features/profile/presentation/pages/profile_page.dart
@@ -1,31 +1,23 @@
 import 'package:flutter/material.dart';
 import 'package:easy_localization/easy_localization.dart';
-import 'dart:ui';
 import 'package:lexilingo_app/features/admin/admin_app.dart';
-import 'package:lexilingo_app/features/achievements/data/badge_asset_mapper.dart';
-import 'package:lexilingo_app/features/achievements/domain/entities/achievement_entity.dart';
-import 'package:lexilingo_app/features/achievements/presentation/screens/achievements_screen.dart';
-import 'package:lexilingo_app/features/achievements/presentation/widgets/achievement_widgets.dart';
 import 'package:lexilingo_app/features/auth/domain/entities/user_entity.dart';
 import 'package:lexilingo_app/features/auth/presentation/providers/auth_provider.dart';
 import 'package:lexilingo_app/features/gamification/gamification.dart';
 import 'package:lexilingo_app/features/level/level.dart';
-import 'package:lexilingo_app/features/profile/presentation/pages/edit_profile_screen.dart';
 import 'package:lexilingo_app/features/profile/presentation/providers/profile_provider.dart';
-import 'package:lexilingo_app/features/profile/presentation/widgets/profile_ui_components.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/admin_panel_tile.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/learning_stats_section.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/level_progress_card.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/profile_header.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/quick_actions_row.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/recent_badges_section.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/weekly_activity_section.dart';
 import 'package:lexilingo_app/features/progress/presentation/providers/progress_provider.dart';
-import 'package:lexilingo_app/features/progress/presentation/screens/my_progress_screen.dart';
-import 'package:lexilingo_app/features/social/social.dart';
 import 'package:lexilingo_app/features/user/presentation/pages/settings_page.dart';
 import 'package:lexilingo_app/features/voice/presentation/screens/voice_practice_screen.dart';
-import 'package:lexilingo_app/features/profile/presentation/pages/learning_stats_pages.dart';
-import 'package:lexilingo_app/features/user/domain/entities/weekly_activity_entity.dart';
-import 'package:lexilingo_app/core/widgets/glassmorphic_components.dart'
-    as glass;
-import 'package:lexilingo_app/core/widgets/network_avatar_image.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
-import 'package:lexilingo_app/core/widgets/skeleton_loading.dart';
 
 class ProfilePage extends StatefulWidget {
   const ProfilePage({super.key});
@@ -34,29 +26,15 @@ class ProfilePage extends StatefulWidget {
   State<ProfilePage> createState() => _ProfilePageState();
 }
 
-class _ProfilePageState extends State<ProfilePage>
-    with SingleTickerProviderStateMixin {
-  late final AnimationController _badgeShineController;
-
+class _ProfilePageState extends State<ProfilePage> {
   @override
   void initState() {
     super.initState();
-    _badgeShineController = AnimationController(
-      vsync: this,
-      duration: const Duration(milliseconds: 3000),
-    )..repeat();
-
     WidgetsBinding.instance.addPostFrameCallback((_) {
       _loadData();
     });
   }
 
-  @override
-  void dispose() {
-    _badgeShineController.dispose();
-    super.dispose();
-  }
-
   Future<void> _loadData() async {
     final authProvider = context.read<AuthProvider>();
     final levelProvider = context.read<LevelProvider>();
@@ -97,13 +75,6 @@ class _ProfilePageState extends State<ProfilePage>
     );
   }
 
-  String _formatMemberSince(BuildContext context, DateTime? createdAt) {
-    if (createdAt == null) return 'profile.member'.tr();
-    return 'profile.memberSince'.tr(
-      namedArgs: {'date': DateFormat('MMM yyyy').format(createdAt)},
-    );
-  }
-
   @override
   Widget build(BuildContext context) {
     final authProvider = Provider.of<AuthProvider>(context);
@@ -144,7 +115,7 @@ class _ProfilePageState extends State<ProfilePage>
                     ),
                   ),
                   Text(
-                    _formatMemberSince(context, user?.createdAt),
+                    formatMemberSince(context, user?.createdAt),
                     maxLines: 1,
                     overflow: TextOverflow.ellipsis,
                     style: Theme.of(context).textTheme.bodySmall?.copyWith(
@@ -211,6 +182,13 @@ class _ProfilePageState extends State<ProfilePage>
               );
             },
           ),
+          IconButton(
+            icon: Icon(Icons.workspace_premium_rounded, color: accent),
+            tooltip: 'premium.title'.tr(),
+            onPressed: () {
+              Navigator.pushNamed(context, '/premium');
+            },
+          ),
           IconButton(
             icon: Icon(Icons.settings, color: accent),
             onPressed: () {
@@ -234,1990 +212,43 @@ class _ProfilePageState extends State<ProfilePage>
         child: SingleChildScrollView(
           physics: const AlwaysScrollableScrollPhysics(),
           padding: const EdgeInsets.only(bottom: 24),
-          child: Column(
-            children: [
-              // Profile Header
-              _buildProfileHeader(context, user),
-
-              // Quick Actions (Shop, Leaderboard, Social, Wallet)
-              _buildQuickActions(context),
-
-              // Level Progress Card
-              _buildLevelProgressCard(context),
-
-              // AI Proficiency Assessment (radar chart)
-              const ProficiencyCard(),
-
-              // Learning Stats
-              _buildLearningStats(context, user),
-
-              // Weekly Activity
-              _buildWeeklyActivity(context),
-
-              // Recent Badges
-              _buildRecentBadges(context),
-
-              // Admin Panel shortcut (only for authorised accounts)
-              if (_isAdminUser(user)) _buildAdminPanelTile(context),
-
-              const SizedBox(height: 80),
-            ],
-          ),
-        ),
-      ),
-    );
-  }
-
-  /// Quick Actions Grid - Navigate to new gamification/social features
-  Widget _buildQuickActions(BuildContext context) {
-    return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
-      child: Row(
-        children: [
-          _buildQuickActionButton(
-            context,
-            icon: Icons.store,
-            label: 'profile.shop'.tr(),
-            color: AppColors.orange,
-            gradient: AppColors.warmGradient,
-            onTap: () => Navigator.push(
-              context,
-              MaterialPageRoute(builder: (_) => const ShopScreen()),
-            ),
-          ),
-          const SizedBox(width: 12),
-          _buildQuickActionButton(
-            context,
-            icon: Icons.leaderboard,
-            label: 'profile.ranks'.tr(),
-            color: AppColors.greenSuccess,
-            gradient: AppColors.successGradient,
-            onTap: () => Navigator.push(
-              context,
-              MaterialPageRoute(builder: (_) => const LeaderboardScreen()),
-            ),
-          ),
-          const SizedBox(width: 12),
-          _buildQuickActionButton(
-            context,
-            icon: Icons.people,
-            label: 'profile.friends'.tr(),
-            color: AppColorRoles.primary(
-              Theme.of(context).brightness == Brightness.dark,
-            ),
-            gradient: Theme.of(context).brightness == Brightness.dark
-                ? AppColors.primaryGradientDark
-                : AppColors.indigoGradient,
-            onTap: () => Navigator.push(
-              context,
-              MaterialPageRoute(builder: (_) => const SocialScreen()),
-            ),
-          ),
-          const SizedBox(width: 12),
-          _buildQuickActionButton(
-            context,
-            icon: Icons.insights_rounded,
-            label: 'profile.progress'.tr(),
-            color: AppColors.purple,
-            gradient: AppColors.purpleGradient,
-            onTap: () => Navigator.push(
-              context,
-              MaterialPageRoute(builder: (_) => const MyProgressScreen()),
-            ),
-          ),
-        ],
-      ),
-    );
-  }
-
-  Widget _buildQuickActionButton(
-    BuildContext context, {
-    required IconData icon,
-    required String label,
-    required Color color,
-    required List<Color> gradient,
-    required VoidCallback onTap,
-  }) {
-    return Expanded(
-      child: GestureDetector(
-        onTap: onTap,
-        child: Container(
-          padding: const EdgeInsets.symmetric(vertical: 12),
-          decoration: BoxDecoration(
-            gradient: LinearGradient(
-              colors: gradient,
-              begin: Alignment.topLeft,
-              end: Alignment.bottomRight,
-            ),
-            borderRadius: BorderRadius.circular(12),
-            boxShadow: [
-              BoxShadow(
-                color: color.withValues(alpha: 0.3),
-                blurRadius: 8,
-                offset: Offset(0, 4),
-              ),
-            ],
-          ),
-          child: Column(
-            mainAxisSize: MainAxisSize.min,
-            children: [
-              Icon(
-                icon,
-                color: Theme.of(context).colorScheme.surface,
-                size: 24,
-              ),
-              const SizedBox(height: 4),
-              Text(
-                label,
-                style: TextStyle(
-                  color: Theme.of(context).colorScheme.surface,
-                  fontSize: 11,
-                  fontWeight: FontWeight.w600,
-                ),
-              ),
-            ],
-          ),
-        ),
-      ),
-    );
-  }
-
-  Widget _buildProfileHeader(BuildContext context, dynamic user) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final accent = AppColorRoles.primary(isDark);
-    return Consumer<LevelProvider>(
-      builder: (context, levelProvider, child) {
-        // Use numeric level progress, not CEFR-based
-        final progress = levelProvider.displayLevelProgress;
-
-        return Container(
-          margin: const EdgeInsets.all(16),
-          child: Stack(
-            children: [
-              // Glassmorphic Background Card
-              ClipRRect(
-                borderRadius: BorderRadius.circular(24),
-                child: BackdropFilter(
-                  filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
-                  child: Container(
-                    width: double.infinity,
-                    padding: const EdgeInsets.all(24),
-                    decoration: BoxDecoration(
-                      gradient: LinearGradient(
-                        begin: Alignment.topLeft,
-                        end: Alignment.bottomRight,
-                        colors: [
-                          (isDark ? accent : AppColors.primary).withValues(
-                            alpha: 0.15,
-                          ),
-                          (isDark ? accent : AppColors.primary).withValues(
-                            alpha: 0.1,
-                          ),
-                          AppColors.surfaceLight.withValues(alpha: 0.05),
-                        ],
-                      ),
-                      borderRadius: BorderRadius.circular(24),
-                      border: Border.all(
-                        color: Theme.of(
-                          context,
-                        ).colorScheme.surface.withValues(alpha: 0.2),
-                        width: 1.5,
-                      ),
-                      boxShadow: [
-                        BoxShadow(
-                          color: (isDark ? accent : AppColors.primary)
-                              .withValues(alpha: 0.12),
-                          blurRadius: 20,
-                          offset: const Offset(0, 10),
-                        ),
-                      ],
-                    ),
-                    child: Column(
-                      children: [
-                        // Avatar with animated progress ring
-                        Stack(
-                          alignment: Alignment.center,
-                          children: [
-                            // Progress Ring
-                            glass.AnimatedProgressRing(
-                              progress: progress,
-                              size: 140,
-                              strokeWidth: 6,
-                              gradientColors: [
-                                isDark ? accent : AppColors.primary,
-                                isDark ? accent : AppColors.primary,
-                                AppColors.purple,
-                              ],
-                              child: Container(
-                                width: 120,
-                                height: 120,
-                                decoration: BoxDecoration(
-                                  shape: BoxShape.circle,
-                                  border: Border.all(
-                                    color: Theme.of(context).colorScheme.surface
-                                        .withValues(alpha: 0.5),
-                                    width: 3,
-                                  ),
-                                  boxShadow: [
-                                    BoxShadow(
-                                      color:
-                                          (isDark ? accent : AppColors.primary)
-                                              .withValues(alpha: 0.3),
-                                      blurRadius: 20,
-                                      spreadRadius: 5,
-                                    ),
-                                  ],
-                                ),
-                                child: ClipOval(
-                                  child: NetworkAvatarImage(
-                                    imageUrl: user?.avatarUrl,
-                                    fit: BoxFit.cover,
-                                    width: 120,
-                                    height: 120,
-                                    fallback: Container(
-                                      color:
-                                          (isDark ? accent : AppColors.primary)
-                                              .withValues(alpha: 0.2),
-                                      child: Icon(
-                                        Icons.person,
-                                        size: 60,
-                                        color: isDark
-                                            ? accent
-                                            : AppColors.primary,
-                                      ),
-                                    ),
-                                  ),
-                                ),
-                              ),
-                            ),
-                            // Verified Badge
-                            if (user?.isVerified == true)
-                              Positioned(
-                                bottom: 10,
-                                right: 10,
-                                child: Container(
-                                  padding: const EdgeInsets.all(6),
-                                  decoration: BoxDecoration(
-                                    gradient: LinearGradient(
-                                      colors: [
-                                        isDark ? accent : AppColors.primary,
-                                        isDark ? accent : AppColors.primary,
-                                      ],
-                                    ),
-                                    shape: BoxShape.circle,
-                                    border: Border.all(
-                                      color: AppColors.surfaceLight,
-                                      width: 2,
-                                    ),
-                                    boxShadow: [
-                                      BoxShadow(
-                                        color:
-                                            (isDark
-                                                    ? accent
-                                                    : AppColors.primary)
-                                                .withValues(alpha: 0.5),
-                                        blurRadius: 8,
-                                      ),
-                                    ],
-                                  ),
-                                  child: Icon(
-                                    Icons.verified,
-                                    color: AppColors.surfaceLight,
-                                    size: 16,
-                                  ),
-                                ),
-                              ),
-                          ],
-                        ),
-                        const SizedBox(height: 20),
-                        // User Name
-                        Text(
-                          user?.displayName ?? 'profile.guestUser'.tr(),
-                          textAlign: TextAlign.center,
-                          style: Theme.of(context).textTheme.headlineSmall
-                              ?.copyWith(
-                                fontWeight: FontWeight.bold,
-                                letterSpacing: -0.5,
-                              ),
-                        ),
-                        const SizedBox(height: 6),
-                        // Email
-                        if (user?.email != null)
-                          Text(
-                            user.email,
-                            style: const TextStyle(
-                              color: AppColors.grey600,
-                              fontSize: 13,
-                            ),
-                          ),
-                        const SizedBox(height: 12),
-                        // Level Badge + CEFR Proficiency Badge + Rank Badge
-                        Consumer<LevelProvider>(
-                          builder: (_, lp, __) {
-                            final rankData = rankVisualDataFor(lp.rank);
-                            final isMasterRank = lp.rank == 'master';
-                            return Wrap(
-                              spacing: 8,
-                              runSpacing: 8,
-                              alignment: WrapAlignment.center,
-                              children: [
-                                // Numeric Level badge
-                                Container(
-                                  padding: const EdgeInsets.symmetric(
-                                    horizontal: 16,
-                                    vertical: 8,
-                                  ),
-                                  decoration: BoxDecoration(
-                                    gradient: LinearGradient(
-                                      colors: AppColorRoles.primaryGradient(
-                                        isDark,
-                                      ),
-                                    ),
-                                    borderRadius: BorderRadius.circular(20),
-                                    boxShadow: [
-                                      BoxShadow(
-                                        color: (isDark
-                                                ? accent
-                                                : AppColors.primary)
-                                            .withValues(alpha: 0.4),
-                                        blurRadius: 8,
-                                        offset: const Offset(0, 4),
-                                      ),
-                                    ],
-                                  ),
-                                  child: Row(
-                                    mainAxisSize: MainAxisSize.min,
-                                    children: [
-                                      Icon(
-                                        Icons.workspace_premium_rounded,
-                                        color: AppColors.surfaceLight,
-                                        size: 16,
-                                      ),
-                                      const SizedBox(width: 6),
-                                      Text(
-                                        'profile.level'.tr(
-                                          namedArgs: {
-                                            'level': '${lp.displayLevel}',
-                                          },
-                                        ),
-                                        style: TextStyle(
-                                          color: AppColors.surfaceLight,
-                                          fontWeight: FontWeight.bold,
-                                          fontSize: 13,
-                                        ),
-                                      ),
-                                    ],
-                                  ),
-                                ),
-                                // CEFR Proficiency Badge
-                                Container(
-                                  padding: const EdgeInsets.symmetric(
-                                    horizontal: 12,
-                                    vertical: 8,
-                                  ),
-                                  decoration: BoxDecoration(
-                                    color: _getTierColor(
-                                      lp.proficiencyLevel,
-                                    ).withValues(alpha: 0.12),
-                                    borderRadius: BorderRadius.circular(20),
-                                    border: Border.all(
-                                      color: _getTierColor(
-                                        lp.proficiencyLevel,
-                                      ).withValues(alpha: 0.5),
-                                    ),
-                                  ),
-                                  child: Row(
-                                    mainAxisSize: MainAxisSize.min,
-                                    children: [
-                                      Icon(
-                                        _getTierIcon(lp.proficiencyLevel),
-                                        size: 14,
-                                        color: _getTierColor(
-                                          lp.proficiencyLevel,
-                                        ),
-                                      ),
-                                      const SizedBox(width: 4),
-                                      Text(
-                                        lp.proficiencyLevel,
-                                        style: TextStyle(
-                                          color: _getTierColor(
-                                            lp.proficiencyLevel,
-                                          ),
-                                          fontWeight: FontWeight.bold,
-                                          fontSize: 13,
-                                        ),
-                                      ),
-                                      const SizedBox(width: 4),
-                                      Text(
-                                        '·',
-                                        style: TextStyle(
-                                          color: _getTierColor(
-                                            lp.proficiencyLevel,
-                                          ).withValues(alpha: 0.6),
-                                          fontSize: 13,
-                                        ),
-                                      ),
-                                      const SizedBox(width: 4),
-                                      Text(
-                                        lp.proficiencyName,
-                                        style: TextStyle(
-                                          color: _getTierColor(
-                                            lp.proficiencyLevel,
-                                          ),
-                                          fontWeight: FontWeight.w500,
-                                          fontSize: 12,
-                                        ),
-                                      ),
-                                    ],
-                                  ),
-                                ),
-                                // League Rank Badge
-                                GestureDetector(
-                                  onTap: () => Navigator.push(
-                                    context,
-                                    MaterialPageRoute(
-                                      builder: (_) =>
-                                          const LeaderboardScreen(),
-                                    ),
-                                  ),
-                                  child: isMasterRank
-                                      ? ShaderMask(
-                                          shaderCallback: (bounds) =>
-                                              const LinearGradient(
-                                                colors: [
-                                                  Color(0xFF5AB6FF),
-                                                  Color(0xFFFFD64F),
-                                                ],
-                                                begin: Alignment.topLeft,
-                                                end: Alignment.bottomRight,
-                                              ).createShader(bounds),
-                                          child: Container(
-                                            padding: const EdgeInsets.symmetric(
-                                              horizontal: 10,
-                                              vertical: 6,
-                                            ),
-                                            decoration: BoxDecoration(
-                                              color: Colors.white.withValues(
-                                                alpha: 0.12,
-                                              ),
-                                              borderRadius:
-                                                  BorderRadius.circular(20),
-                                              border: Border.all(
-                                                color: Colors.white.withValues(
-                                                  alpha: 0.4,
-                                                ),
-                                              ),
-                                            ),
-                                            child: Row(
-                                              mainAxisSize: MainAxisSize.min,
-                                              children: [
-                                                RankAssetIcon(
-                                                  rank: lp.rank,
-                                                  size: 16,
-                                                  decorated: false,
-                                                ),
-                                                const SizedBox(width: 5),
-                                                Text(
-                                                  lp.rankName,
-                                                  style: const TextStyle(
-                                                    color: Colors.white,
-                                                    fontWeight: FontWeight.bold,
-                                                    fontSize: 12,
-                                                  ),
-                                                ),
-                                              ],
-                                            ),
-                                          ),
-                                        )
-                                      : Container(
-                                          padding: const EdgeInsets.symmetric(
-                                            horizontal: 10,
-                                            vertical: 6,
-                                          ),
-                                          decoration: BoxDecoration(
-                                            color: rankData.color.withValues(
-                                              alpha: 0.1,
-                                            ),
-                                            borderRadius:
-                                                BorderRadius.circular(20),
-                                            border: Border.all(
-                                              color: rankData.color.withValues(
-                                                alpha: 0.4,
-                                              ),
-                                            ),
-                                          ),
-                                          child: Row(
-                                            mainAxisSize: MainAxisSize.min,
-                                            children: [
-                                              RankAssetIcon(
-                                                rank: lp.rank,
-                                                size: 16,
-                                                decorated: false,
-                                              ),
-                                              const SizedBox(width: 5),
-                                              Text(
-                                                lp.rankName,
-                                                style: TextStyle(
-                                                  color: rankData.color,
-                                                  fontWeight: FontWeight.bold,
-                                                  fontSize: 12,
-                                                ),
-                                              ),
-                                            ],
-                                          ),
-                                        ),
-                                ),
-                              ],
-                            );
-                          },
-                        ),
-                        const SizedBox(height: 8),
-                        // Member Since
-                        Text(
-                          _formatMemberSince(context, user?.createdAt),
-                          style: const TextStyle(
-                            color: AppColors.grey600,
-                            fontSize: 12,
-                          ),
-                        ),
-                        const SizedBox(height: 12),
-                        // Edit Profile Button
-                        GestureDetector(
-                          onTap: () async {
-                            final result = await Navigator.push(
-                              context,
-                              MaterialPageRoute(
-                                builder: (_) => const EditProfileScreen(),
-                              ),
-                            );
-                            if (result == true) {
-                              _loadData(); // Refresh after edit
-                            }
-                          },
-                          child: Container(
-                            padding: const EdgeInsets.symmetric(
-                              horizontal: 20,
-                              vertical: 8,
-                            ),
-                            decoration: BoxDecoration(
-                              gradient: LinearGradient(
-                                colors: AppColorRoles.primaryGradient(isDark),
-                              ),
-                              borderRadius: BorderRadius.circular(20),
-                              boxShadow: [
-                                BoxShadow(
-                                  color: (isDark ? accent : AppColors.primary)
-                                      .withValues(alpha: 0.3),
-                                  blurRadius: 8,
-                                  offset: Offset(0, 4),
-                                ),
-                              ],
-                            ),
-                            child: Row(
-                              mainAxisSize: MainAxisSize.min,
-                              children: [
-                                Icon(
-                                  Icons.edit,
-                                  color: AppColors.surfaceLight,
-                                  size: 14,
-                                ),
-                                SizedBox(width: 6),
-                                Text(
-                                  'profile.editProfile'.tr(),
-                                  style: TextStyle(
-                                    color: AppColors.surfaceLight,
-                                    fontWeight: FontWeight.bold,
-                                    fontSize: 13,
-                                  ),
-                                ),
-                              ],
-                            ),
-                          ),
-                        ),
-                        const SizedBox(height: 20),
-                        // Social Stats Row
-                        _buildSocialStatsRow(context),
-                      ],
-                    ),
-                  ),
-                ),
-              ),
-            ],
-          ),
-        );
-      },
-    );
-  }
-
-  /// Social stats row showing XP, followers, following
-  Widget _buildSocialStatsRow(BuildContext context) {
-    return Consumer<ProfileProvider>(
-      builder: (context, profileProvider, _) {
-        final stats = profileProvider.stats;
-
-        return Row(
-          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
-          children: [
-            AnimatedSocialStat(
-              value: '${stats?.totalVocabularyMastered ?? 0}',
-              label: 'profile.words'.tr(),
-              icon: Icons.spellcheck_rounded,
-              color: AppColors.greenSuccessBright,
-            ),
-            Container(
-              height: 40,
-              width: 1,
-              color: AppColors.grey400.withValues(alpha: 0.5),
-            ),
-            AnimatedSocialStat(
-              value: '${stats?.totalLessonsCompleted ?? 0}',
-              label: 'profile.lessons'.tr(),
-              icon: Icons.menu_book,
-              color: AppColorRoles.primary(
-                Theme.of(context).brightness == Brightness.dark,
-              ),
-            ),
-            Container(
-              height: 40,
-              width: 1,
-              color: AppColors.grey400.withValues(alpha: 0.5),
-            ),
-            AnimatedSocialStat(
-              value: '${stats?.currentStreak ?? 0}',
-              label: 'profile.dayStreak'.tr(),
-              icon: Icons.local_fire_department,
-              color: AppColors.dangerGradient[0],
-            ),
-          ],
-        );
-      },
-    );
-  }
-
-  IconData _getTierIcon(String tierCode) {
-    switch (tierCode) {
-      case 'A1':
-        return Icons.eco;
-      case 'A2':
-        return Icons.spa;
-      case 'B1':
-        return Icons.bolt;
-      case 'B2':
-        return Icons.rocket_launch;
-      case 'C1':
-        return Icons.workspace_premium;
-      case 'C2':
-        return Icons.diamond;
-      default:
-        return Icons.star;
-    }
-  }
-
-  Widget _buildLevelProgressCard(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    return Consumer<LevelProvider>(
-      builder: (context, levelProvider, child) {
-        final level = levelProvider.displayLevel;
-        final xpIn = levelProvider.displayXpInLevel;
-        final xpFor = levelProvider.displayXpForNextLevel;
-        final progress = levelProvider.displayLevelProgress;
-
-        return GlassmorphicContainer(
-          child: Column(
-            children: [
-              Row(
-                mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                children: [
-                  Text(
-                    'profile.levelRange'.tr(
-                      namedArgs: {
-                        'level': '$level',
-                        'nextLevel': '${level + 1}',
-                      },
-                    ),
-                    style: const TextStyle(fontWeight: FontWeight.w500),
-                  ),
-                  Text(
-                    'profile.xpProgress'.tr(
-                      namedArgs: {'current': '$xpIn', 'total': '$xpFor'},
-                    ),
-                    style: const TextStyle(fontSize: 14),
-                  ),
-                ],
-              ),
-              const SizedBox(height: 12),
-              ClipRRect(
-                borderRadius: BorderRadius.circular(6),
-                child: LinearProgressIndicator(
-                  value: progress,
-                  backgroundColor: AppColorRoles.primary(
-                    isDark,
-                  ).withValues(alpha: 0.18),
-                  valueColor: AlwaysStoppedAnimation<Color>(
-                    AppColorRoles.primary(isDark),
-                  ),
-                  minHeight: 12,
-                ),
-              ),
-              const SizedBox(height: 12),
-              Row(
-                mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                children: [
-                  Text(
-                    'profile.xpToNextLevel'.tr(
-                      namedArgs: {
-                        'xp': '${xpFor - xpIn}',
-                        'level': '${level + 1}',
-                      },
-                    ),
-                    style: TextStyle(
-                      color: Theme.of(context).colorScheme.onSurfaceVariant,
-                      fontSize: 12,
-                    ),
-                  ),
-                  Text(
-                    'profile.percentComplete'.tr(
-                      namedArgs: {
-                        'percent': (progress * 100).toStringAsFixed(0),
-                      },
-                    ),
-                    style: TextStyle(
-                      color: AppColorRoles.primary(isDark),
-                      fontSize: 12,
-                      fontWeight: FontWeight.bold,
-                    ),
-                  ),
-                ],
-              ),
-            ],
-          ),
-        );
-      },
-    );
-  }
-
-  Color _getTierColor(String tierCode) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    switch (tierCode) {
-      case 'A1':
-        return AppColors.greenSuccessBright;
-      case 'A2':
-        return AppColors.teal;
-      case 'B1':
-        return AppColorRoles.primary(isDark);
-      case 'B2':
-        return AppColorRoles.primaryDeep(isDark);
-      case 'C1':
-        return AppColors.purple;
-      case 'C2':
-        return AppColors.warning;
-      default:
-        return AppColorRoles.primary(isDark);
-    }
-  }
-
-  Widget _buildLearningStats(BuildContext context, dynamic user) {
-    return Consumer<ProfileProvider>(
-      builder: (context, profileProvider, child) {
-        final isDark = Theme.of(context).brightness == Brightness.dark;
-        final primaryColor = AppColorRoles.primary(isDark);
-        // Use stats from ProfileProvider (backend API)
-        final stats = profileProvider.stats;
-        final lessonsCompleted = stats?.totalLessonsCompleted ?? 0;
-        final coursesCompleted = stats?.totalCoursesCompleted ?? 0;
-        final vocabularyMastered = stats?.totalVocabularyMastered ?? 0;
-        final testsPassed = stats?.totalTestsPassed ?? 0;
-        final avgScore = stats?.averageTestScore ?? 0.0;
-
-        // Show loading state
-        if (profileProvider.isLoadingStats && stats == null) {
-          return _buildLoadingStats(context);
-        }
-
-        return Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            Padding(
-              padding: const EdgeInsets.all(16.0),
-              child: Row(
-                children: [
-                  Icon(Icons.insights_rounded, color: primaryColor, size: 20),
-                  const SizedBox(width: 8),
-                  Text(
-                    'profile.learningStats'.tr(),
-                    style: Theme.of(context).textTheme.titleLarge?.copyWith(
-                      fontWeight: FontWeight.bold,
-                    ),
-                  ),
-                ],
-              ),
-            ),
-            Padding(
-              padding: const EdgeInsets.symmetric(horizontal: 16),
+          child: Center(
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxWidth: 960),
               child: Column(
                 children: [
-                  Row(
-                    children: [
-                      Expanded(
-                        child: GlassmorphicStatCard(
-                          icon: Icons.abc,
-                          color: primaryColor,
-                          title: 'profile.lessons'.tr(),
-                          value: '$lessonsCompleted',
-                          subtitle: 'profile.completed'.tr(),
-                          valueInRightCircle: true,
-                          valueCircleSize: 40,
-                          valueCircleFontSize: 18,
-                          isAction: true,
-                          onTap: () => Navigator.push(
-                            context,
-                            MaterialPageRoute(
-                              builder: (_) => const LearningLessonsStatsPage(),
-                            ),
-                          ),
-                          iconBoxSize: 28,
-                          iconSize: 14,
-                          titleFontSize: 13,
-                          subtitleFontSize: 11,
-                          contentPadding: const EdgeInsets.symmetric(
-                            horizontal: 12,
-                            vertical: 10,
-                          ),
-                        ),
-                      ),
-                      const SizedBox(width: 10),
-                      Expanded(
-                        child: GlassmorphicStatCard(
-                          icon: Icons.school,
-                          color: primaryColor,
-                          title: 'profile.courses'.tr(),
-                          value: '$coursesCompleted',
-                          subtitle: 'profile.finished'.tr(),
-                          valueInRightCircle: true,
-                          valueCircleSize: 40,
-                          valueCircleFontSize: 18,
-                          isAction: true,
-                          onTap: () => Navigator.push(
-                            context,
-                            MaterialPageRoute(
-                              builder: (_) => const LearningCoursesStatsPage(),
-                            ),
-                          ),
-                          iconBoxSize: 28,
-                          iconSize: 14,
-                          titleFontSize: 13,
-                          subtitleFontSize: 11,
-                          contentPadding: const EdgeInsets.symmetric(
-                            horizontal: 12,
-                            vertical: 10,
-                          ),
-                        ),
-                      ),
-                    ],
-                  ),
-                  const SizedBox(height: 10),
-                  Row(
-                    children: [
-                      Expanded(
-                        child: GlassmorphicStatCard(
-                          icon: Icons.auto_stories,
-                          color: primaryColor,
-                          title: 'profile.vocabulary'.tr(),
-                          value: '$vocabularyMastered',
-                          subtitle: 'profile.mastered'.tr(),
-                          valueInRightCircle: true,
-                          valueCircleSize: 40,
-                          valueCircleFontSize: 18,
-                          isAction: true,
-                          onTap: () => Navigator.push(
-                            context,
-                            MaterialPageRoute(
-                              builder: (_) =>
-                                  const LearningVocabularyStatsPage(),
-                            ),
-                          ),
-                          iconBoxSize: 28,
-                          iconSize: 14,
-                          titleFontSize: 13,
-                          subtitleFontSize: 11,
-                          contentPadding: const EdgeInsets.symmetric(
-                            horizontal: 12,
-                            vertical: 10,
-                          ),
-                        ),
-                      ),
-                      const SizedBox(width: 10),
-                      Expanded(
-                        child: GlassmorphicStatCard(
-                          icon: Icons.quiz,
-                          color: primaryColor,
-                          title: 'profile.tests'.tr(),
-                          value: '$testsPassed',
-                          subtitle: avgScore > 0
-                              ? 'profile.averagePercent'.tr(
-                                  namedArgs: {
-                                    'percent': avgScore.toStringAsFixed(0),
-                                  },
-                                )
-                              : 'profile.passed'.tr(),
-                          valueInRightCircle: true,
-                          valueCircleSize: 40,
-                          valueCircleFontSize: 18,
-                          isAction: true,
-                          onTap: () => Navigator.push(
-                            context,
-                            MaterialPageRoute(
-                              builder: (_) => const LearningTestsStatsPage(),
-                            ),
-                          ),
-                          iconBoxSize: 28,
-                          iconSize: 14,
-                          titleFontSize: 13,
-                          subtitleFontSize: 11,
-                          contentPadding: const EdgeInsets.symmetric(
-                            horizontal: 12,
-                            vertical: 10,
-                          ),
-                        ),
-                      ),
-                    ],
-                  ),
-                ],
-              ),
-            ),
-          ],
-        );
-      },
-    );
-  }
+                  // Profile Header
+                  ProfileHeader(user: user, onProfileEdited: _loadData),
 
-  Widget _buildLoadingStats(BuildContext context) {
-    return Column(
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: [
-        Padding(
-          padding: const EdgeInsets.all(16.0),
-          child: Text(
-            'profile.learningStats'.tr(),
-            style: Theme.of(
-              context,
-            ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
-          ),
-        ),
-        GridView.count(
-          crossAxisCount: 2,
-          shrinkWrap: true,
-          physics: const NeverScrollableScrollPhysics(),
-          padding: const EdgeInsets.symmetric(horizontal: 16),
-          crossAxisSpacing: 12,
-          mainAxisSpacing: 12,
-          childAspectRatio: 1.15,
-          children: List.generate(
-            4,
-            (index) => ShimmerContainer(
-              child: SkeletonBox(height: double.infinity, borderRadius: 12),
-            ),
-          ),
-        ),
-      ],
-    );
-  }
+                  // Quick Actions (Shop, Leaderboard, Social, Wallet)
+                  const QuickActionsRow(),
 
-  void _showWeeklyActivityDetail(
-    BuildContext context,
-    List<WeeklyActivityEntity> activities,
-  ) {
-    showModalBottomSheet(
-      context: context,
-      isScrollControlled: true,
-      backgroundColor: Colors.transparent,
-      builder: (_) => _WeeklyActivityDetailSheet(activities: activities),
-    );
-  }
+                  // Level Progress Card
+                  const ProfileLevelProgressCard(),
 
-  Widget _buildWeeklyActivity(BuildContext context) {
-    return Consumer<ProfileProvider>(
-      builder: (context, profileProvider, child) {
-        final isDark = Theme.of(context).brightness == Brightness.dark;
-        final activities = profileProvider.weeklyActivity;
-        final isLoading = profileProvider.isLoadingActivity;
-        final activityError = profileProvider.activityError;
+                  // AI Proficiency Assessment (radar chart)
+                  const ProficiencyCard(),
 
-        return Column(
-          children: [
-            Padding(
-              padding: const EdgeInsets.symmetric(
-                horizontal: 16.0,
-                vertical: 16,
-              ),
-              child: Row(
-                mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                children: [
-                  Text(
-                    'profile.weeklyActivity'.tr(),
-                    style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
-                  ),
-                  GestureDetector(
-                    onTap: activities.isNotEmpty
-                        ? () => _showWeeklyActivityDetail(context, activities)
-                        : null,
-                    child: Row(
-                      mainAxisSize: MainAxisSize.min,
-                      children: [
-                        Text(
-                          'profile.last7Days'.tr(),
-                          style: TextStyle(
-                            color: Theme.of(
-                              context,
-                            ).colorScheme.onSurfaceVariant,
-                            fontSize: 12,
-                            fontWeight: FontWeight.w500,
-                          ),
-                        ),
-                        if (activities.isNotEmpty) ...[
-                          const SizedBox(width: 4),
-                          Icon(
-                            Icons.chevron_right,
-                            size: 16,
-                            color: Theme.of(
-                              context,
-                            ).colorScheme.onSurfaceVariant,
-                          ),
-                        ],
-                      ],
-                    ),
-                  ),
-                ],
-              ),
-            ),
-            GlassmorphicContainer(
-              child: isLoading && activities.isEmpty
-                  ? SizedBox(
-                      width: double.infinity,
-                      child: Padding(
-                        padding: const EdgeInsets.all(24.0),
-                        child: ShimmerContainer(
-                          child: Column(
-                            crossAxisAlignment: CrossAxisAlignment.start,
-                            children: [
-                              SizedBox(
-                                height: 120,
-                                child: Row(
-                                  mainAxisAlignment:
-                                      MainAxisAlignment.spaceBetween,
-                                  crossAxisAlignment: CrossAxisAlignment.end,
-                                  children: List.generate(
-                                    7,
-                                    (index) => Expanded(
-                                      child: Padding(
-                                        padding: const EdgeInsets.symmetric(
-                                          horizontal: 4,
-                                        ),
-                                        child: SkeletonBox(
-                                          height: 20.0 + (index % 3) * 30.0,
-                                          borderRadius: 4,
-                                        ),
-                                      ),
-                                    ),
-                                  ),
-                                ),
-                              ),
-                              const SizedBox(height: 6),
-                              Row(
-                                children: List.generate(
-                                  7,
-                                  (index) => const Expanded(
-                                    child: Center(
-                                      child: SkeletonBox(
-                                        width: 20,
-                                        height: 12,
-                                        borderRadius: 2,
-                                      ),
-                                    ),
-                                  ),
-                                ),
-                              ),
-                              const SizedBox(height: 16),
-                              Row(
-                                mainAxisAlignment:
-                                    MainAxisAlignment.spaceAround,
-                                children: List.generate(
-                                  3,
-                                  (index) => const Column(
-                                    children: [
-                                      SkeletonCircle(size: 20),
-                                      SizedBox(height: 4),
-                                      SkeletonBox(
-                                        width: 40,
-                                        height: 16,
-                                        borderRadius: 4,
-                                      ),
-                                      SizedBox(height: 4),
-                                      SkeletonBox(
-                                        width: 60,
-                                        height: 12,
-                                        borderRadius: 4,
-                                      ),
-                                    ],
-                                  ),
-                                ),
-                              ),
-                            ],
-                          ),
-                        ),
-                      ),
-                    )
-                  : activities.isEmpty
-                  ? Center(
-                      child: Padding(
-                        padding: const EdgeInsets.all(24.0),
-                        child: Text(
-                          activityError == null || activityError.isEmpty
-                              ? 'profile.noActivityDataYet'.tr()
-                              : activityError,
-                          style: const TextStyle(color: AppColors.grey600),
-                          textAlign: TextAlign.center,
-                        ),
-                      ),
-                    )
-                  : Column(
-                      children: [
-                        // XP Chart with animated bars
-                        SizedBox(
-                          height: 120,
-                          child: Row(
-                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                            crossAxisAlignment: CrossAxisAlignment.end,
-                            children: activities.asMap().entries.map((entry) {
-                              final index = entry.key;
-                              final activity = entry.value;
-                              final maxXP = activities
-                                  .map((a) => a.xpEarned)
-                                  .reduce((a, b) => a > b ? a : b);
-                              final normalizedValue = maxXP > 0
-                                  ? activity.xpEarned / maxXP
-                                  : 0.0;
+                  // Learning Stats
+                  const LearningStatsSection(),
 
-                              return Expanded(
-                                child: AnimatedActivityBar(
-                                  label: '',
-                                  value: normalizedValue,
-                                  xpValue: activity.xpEarned,
-                                  color: AppColorRoles.primary(isDark),
-                                  delay: Duration(milliseconds: index * 100),
-                                ),
-                              );
-                            }).toList(),
-                          ),
-                        ),
-                        // Day labels row — separate from bars to ensure alignment
-                        const SizedBox(height: 6),
-                        Row(
-                          children: activities.map((activity) {
-                            String dayLabel;
-                            final parsedDate = DateTime.tryParse(activity.date);
-                            if (parsedDate != null) {
-                              dayLabel = DateFormat(
-                                'E',
-                              ).format(parsedDate).substring(0, 1);
-                            } else {
-                              final raw = activity.date.trim();
-                              dayLabel = raw.isEmpty
-                                  ? '-'
-                                  : raw.substring(0, 1).toUpperCase();
-                            }
-                            return Expanded(
-                              child: Center(
-                                child: Text(
-                                  dayLabel,
-                                  style: TextStyle(
-                                    fontSize: 12,
-                                    fontWeight: FontWeight.w500,
-                                    color: isDark
-                                        ? AppColors.grey500
-                                        : AppColors.grey600,
-                                  ),
-                                ),
-                              ),
-                            );
-                          }).toList(),
-                        ),
-                        const SizedBox(height: 16),
-                        // Summary stats
-                        Row(
-                          mainAxisAlignment: MainAxisAlignment.spaceAround,
-                          children: [
-                            _buildActivityStat(
-                              'profile.totalXp'.tr(),
-                              '${activities.fold<int>(0, (sum, a) => sum + a.xpEarned)}',
-                              Icons.star,
-                              AppColors.warning,
-                            ),
-                            _buildActivityStat(
-                              'profile.lessons'.tr(),
-                              '${activities.fold<int>(0, (sum, a) => sum + a.lessonsCompleted)}',
-                              Icons.menu_book,
-                              AppColorRoles.primary(isDark),
-                            ),
-                            _buildActivityStat(
-                              'profile.words'.tr(),
-                              '${activities.fold<int>(0, (sum, a) => sum + a.vocabularyLearned)}',
-                              Icons.abc,
-                              AppColors.greenSuccessBright,
-                            ),
-                          ],
-                        ),
-                      ],
-                    ),
-            ),
-          ],
-        );
-      },
-    );
-  }
+                  // Weekly Activity
+                  const WeeklyActivitySection(),
 
-  Widget _buildActivityStat(
-    String label,
-    String value,
-    IconData icon,
-    Color color,
-  ) {
-    return Column(
-      children: [
-        Icon(icon, size: 20, color: color),
-        const SizedBox(height: 4),
-        Text(
-          value,
-          style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
-        ),
-        Text(
-          label,
-          style: const TextStyle(fontSize: 11, color: AppColors.grey600),
-        ),
-      ],
-    );
-  }
+                  // Recent Badges
+                  const RecentBadgesSection(),
 
-  Widget _buildRecentBadges(BuildContext context) {
-    return Consumer<ProfileProvider>(
-      builder: (context, provider, child) {
-        final badges = provider.recentBadges;
-        final isLoading = provider.isLoadingBadges;
-        final visibleBadges = badges.where(_hasRenderableBadgeImage).toList();
+                  // Admin Panel shortcut (only for authorised accounts)
+                  if (_isAdminUser(user))
+                    AdminPanelTile(onTap: _openAdminPanel),
 
-        return Column(
-          children: [
-            Padding(
-              padding: const EdgeInsets.all(16.0),
-              child: Row(
-                mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                children: [
-                  Text(
-                    'profile.recentBadges'.tr(),
-                    style: Theme.of(context).textTheme.titleLarge?.copyWith(
-                      fontWeight: FontWeight.bold,
-                    ),
-                  ),
-                  TextButton(
-                    onPressed: () {
-                      Navigator.push(
-                        context,
-                        MaterialPageRoute(
-                          builder: (_) => const AchievementsScreen(),
-                        ),
-                      );
-                    },
-                    child: Text('achievements.viewAll'.tr()),
-                  ),
+                  const SizedBox(height: 80),
                 ],
               ),
             ),
-            SizedBox(
-              height: 100,
-              child: isLoading
-                  ? ShimmerContainer(
-                      child: ListView.separated(
-                        scrollDirection: Axis.horizontal,
-                        padding: const EdgeInsets.symmetric(horizontal: 16),
-                        itemCount: 4,
-                        separatorBuilder: (_, __) => const SizedBox(width: 16),
-                        itemBuilder: (context, index) {
-                          return const SkeletonCircle(size: 80);
-                        },
-                      ),
-                    )
-                  : visibleBadges.isEmpty
-                  ? _buildEmptyBadges()
-                  : ListView.separated(
-                      scrollDirection: Axis.horizontal,
-                      padding: const EdgeInsets.symmetric(horizontal: 16),
-                      itemCount: visibleBadges.length,
-                      separatorBuilder: (_, __) => const SizedBox(width: 16),
-                      itemBuilder: (context, index) {
-                        final badge = visibleBadges[index];
-                        return _buildBadgeItemFromEntity(badge);
-                      },
-                    ),
-            ),
-          ],
-        );
-      },
-    );
-  }
-
-  bool _hasRenderableBadgeImage(UserAchievementEntity badge) {
-    final achievement = badge.achievement;
-
-    if (achievement.category.toLowerCase() == 'xp') {
-      return false;
-    }
-
-    final networkBadge = achievement.badgeIcon?.trim();
-    final networkBadgeUri = networkBadge != null && networkBadge.isNotEmpty
-        ? Uri.tryParse(networkBadge)
-        : null;
-    final hasValidNetworkBadge =
-        networkBadgeUri != null &&
-        (networkBadgeUri.scheme == 'http' ||
-            networkBadgeUri.scheme == 'https') &&
-        networkBadgeUri.host.isNotEmpty;
-    if (hasValidNetworkBadge) {
-      return true;
-    }
-
-    final lookupKey = (achievement.slug ?? achievement.id).trim();
-    if (lookupKey.isEmpty) {
-      return false;
-    }
-
-    return BadgeAssetMapper.hasRenderableBadge(lookupKey);
-  }
-
-  /// Build empty badges placeholder
-  Widget _buildEmptyBadges() {
-    return Center(
-      child: Column(
-        mainAxisAlignment: MainAxisAlignment.center,
-        children: [
-          const Icon(
-            Icons.emoji_events_outlined,
-            size: 40,
-            color: AppColors.grey500,
-          ),
-          const SizedBox(height: 8),
-          Text(
-            'profile.completeLessonsToEarnBadges'.tr(),
-            style: const TextStyle(color: AppColors.grey600, fontSize: 12),
-          ),
-        ],
-      ),
-    );
-  }
-
-  /// Build badge item from UserAchievementEntity
-  Widget _buildBadgeItemFromEntity(UserAchievementEntity badge) {
-    final achievement = badge.achievement;
-    const badgeSize = 64.0;
-    final badgeMask = _buildBadgeShineMask(badge, badgeSize);
-
-    return Tooltip(
-      message: '${achievement.name}\n${badge.unlockedTimeAgo}',
-      child: Column(
-        children: [
-          SizedBox(
-            width: badgeSize,
-            height: badgeSize,
-            child: Stack(
-              alignment: Alignment.center,
-              children: [
-                AchievementBadge(
-                  achievement: achievement,
-                  isUnlocked: true,
-                  size: badgeSize,
-                ),
-                Positioned.fill(
-                  child: IgnorePointer(
-                    child: AnimatedBuilder(
-                      animation: _badgeShineController,
-                      builder: (context, child) {
-                        // Smaller sweep portion => longer idle pause per cycle.
-                        const sweepPortion = 0.62;
-                        final progress = _badgeShineController.value;
-                        final isSweeping = progress < sweepPortion;
-                        final sweepT = isSweeping
-                            ? Curves.easeInOut.transform(
-                                progress / sweepPortion,
-                              )
-                            : 1.0;
-                        final position = isSweeping
-                            ? lerpDouble(-1.6, 1.6, sweepT)!
-                            : 2.4;
-
-                        return ShaderMask(
-                          // Apply shine only where the badge image has alpha.
-                          blendMode: BlendMode.srcIn,
-                          shaderCallback: (bounds) {
-                            return LinearGradient(
-                              begin: Alignment(position - 0.45, -1.0),
-                              end: Alignment(position + 0.45, 1.0),
-                              colors: [
-                                AppColors.surfaceLight.withValues(alpha: 0),
-                                AppColors.surfaceLight.withValues(alpha: 0.06),
-                                AppColors.surfaceLight.withValues(alpha: 0.56),
-                                AppColors.surfaceLight.withValues(alpha: 0.06),
-                                AppColors.surfaceLight.withValues(alpha: 0),
-                              ],
-                              stops: const [0.0, 0.42, 0.5, 0.58, 1.0],
-                            ).createShader(bounds);
-                          },
-                          child: child,
-                        );
-                      },
-                      child: badgeMask,
-                    ),
-                  ),
-                ),
-              ],
-            ),
           ),
-          const SizedBox(height: 8),
-          Text(
-            achievement.name,
-            style: const TextStyle(fontSize: 10, fontWeight: FontWeight.w500),
-            overflow: TextOverflow.ellipsis,
-          ),
-        ],
-      ),
-    );
-  }
-
-  Widget _buildBadgeShineMask(UserAchievementEntity badge, double badgeSize) {
-    final achievement = badge.achievement;
-
-    final networkBadge = achievement.badgeIcon?.trim();
-    final networkBadgeUri = networkBadge != null && networkBadge.isNotEmpty
-        ? Uri.tryParse(networkBadge)
-        : null;
-    final hasValidNetworkBadge =
-        networkBadgeUri != null &&
-        (networkBadgeUri.scheme == 'http' ||
-            networkBadgeUri.scheme == 'https') &&
-        networkBadgeUri.host.isNotEmpty;
-
-    if (hasValidNetworkBadge) {
-      return ClipOval(
-        child: Image.network(
-          networkBadge!,
-          width: badgeSize,
-          height: badgeSize,
-          fit: BoxFit.cover,
-          errorBuilder: (_, __, ___) => const SizedBox.shrink(),
-        ),
-      );
-    }
-
-    final lookupKey = (achievement.slug ?? achievement.id).trim();
-    final assetPath = BadgeAssetMapper.getBadgeAsset(lookupKey);
-    if (assetPath != null) {
-      return ClipOval(
-        child: Image.asset(
-          assetPath,
-          width: badgeSize,
-          height: badgeSize,
-          fit: BoxFit.cover,
-          errorBuilder: (_, __, ___) => const SizedBox.shrink(),
-        ),
-      );
-    }
-
-    return const SizedBox.shrink();
-  }
-
-  Widget _buildAdminPanelTile(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
-      child: Material(
-        color: Colors.transparent,
-        child: InkWell(
-          onTap: _openAdminPanel,
-          borderRadius: BorderRadius.circular(16),
-          child: Ink(
-            decoration: BoxDecoration(
-              gradient: const LinearGradient(
-                colors: [Color(0xFFFF6B35), Color(0xFFFF3B00)],
-                begin: Alignment.centerLeft,
-                end: Alignment.centerRight,
-              ),
-              borderRadius: BorderRadius.circular(16),
-              boxShadow: [
-                BoxShadow(
-                  color: Colors.deepOrange.withValues(alpha: isDark ? 0.4 : 0.25),
-                  blurRadius: 12,
-                  offset: const Offset(0, 4),
-                ),
-              ],
-            ),
-            child: Padding(
-              padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 16),
-              child: Row(
-                children: [
-                  Container(
-                    padding: const EdgeInsets.all(8),
-                    decoration: BoxDecoration(
-                      color: Colors.white.withValues(alpha: 0.2),
-                      borderRadius: BorderRadius.circular(10),
-                    ),
-                    child: const Icon(
-                      Icons.admin_panel_settings_rounded,
-                      color: Colors.white,
-                      size: 22,
-                    ),
-                  ),
-                  const SizedBox(width: 14),
-                  const Expanded(
-                    child: Column(
-                      crossAxisAlignment: CrossAxisAlignment.start,
-                      children: [
-                        Text(
-                          'Switch to Admin Panel',
-                          style: TextStyle(
-                            color: Colors.white,
-                            fontWeight: FontWeight.bold,
-                            fontSize: 15,
-                          ),
-                        ),
-                        SizedBox(height: 2),
-                        Text(
-                          'LexiLingo Admin mobile',
-                          style: TextStyle(
-                            color: Colors.white70,
-                            fontSize: 12,
-                          ),
-                        ),
-                      ],
-                    ),
-                  ),
-                  const Icon(
-                    Icons.open_in_new_rounded,
-                    color: Colors.white70,
-                    size: 18,
-                  ),
-                ],
-              ),
-            ),
-          ),
-        ),
-      ),
-    );
-  }
-}
-
-class _WeeklyActivityDetailSheet extends StatelessWidget {
-  final List<WeeklyActivityEntity> activities;
-
-  const _WeeklyActivityDetailSheet({required this.activities});
-
-  @override
-  Widget build(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final primary = AppColorRoles.primary(isDark);
-
-    final totalXP = activities.fold<int>(0, (s, a) => s + a.xpEarned);
-    final totalLessons = activities.fold<int>(
-      0,
-      (s, a) => s + a.lessonsCompleted,
-    );
-    final totalWords = activities.fold<int>(
-      0,
-      (s, a) => s + a.vocabularyLearned,
-    );
-    final maxXP = activities
-        .map((a) => a.xpEarned)
-        .reduce((a, b) => a > b ? a : b);
-    return DraggableScrollableSheet(
-      initialChildSize: 0.75,
-      minChildSize: 0.5,
-      maxChildSize: 0.95,
-      expand: false,
-      builder: (_, scrollController) {
-        return Container(
-          decoration: BoxDecoration(
-            color: isDark ? const Color(0xFF1A1A2E) : Colors.white,
-            borderRadius: const BorderRadius.vertical(top: Radius.circular(24)),
-            boxShadow: [
-              BoxShadow(
-                color: Colors.black.withValues(alpha: 0.2),
-                blurRadius: 20,
-                offset: const Offset(0, -4),
-              ),
-            ],
-          ),
-          child: Column(
-            children: [
-              // Drag handle
-              Container(
-                margin: const EdgeInsets.only(top: 12),
-                width: 40,
-                height: 4,
-                decoration: BoxDecoration(
-                  color: AppColors.grey400,
-                  borderRadius: BorderRadius.circular(2),
-                ),
-              ),
-              // Header
-              Padding(
-                padding: const EdgeInsets.fromLTRB(20, 20, 20, 8),
-                child: Row(
-                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                  children: [
-                    Column(
-                      crossAxisAlignment: CrossAxisAlignment.start,
-                      children: [
-                        Text(
-                          'profile.weeklyActivity'.tr(),
-                          style: TextStyle(
-                            fontSize: 20,
-                            fontWeight: FontWeight.bold,
-                          ),
-                        ),
-                        Text(
-                          'profile.last7DaysDetailedBreakdown'.tr(),
-                          style: TextStyle(
-                            fontSize: 12,
-                            color: Theme.of(
-                              context,
-                            ).colorScheme.onSurfaceVariant,
-                          ),
-                        ),
-                      ],
-                    ),
-                    GestureDetector(
-                      onTap: () => Navigator.pop(context),
-                      child: Container(
-                        padding: const EdgeInsets.all(8),
-                        decoration: BoxDecoration(
-                          color: isDark
-                              ? Colors.white.withValues(alpha: 0.08)
-                              : Colors.black.withValues(alpha: 0.06),
-                          shape: BoxShape.circle,
-                        ),
-                        child: const Icon(Icons.close, size: 16),
-                      ),
-                    ),
-                  ],
-                ),
-              ),
-              // Summary row
-              Padding(
-                padding: const EdgeInsets.symmetric(
-                  horizontal: 20,
-                  vertical: 8,
-                ),
-                child: Row(
-                  children: [
-                    _SummaryChip(
-                      icon: Icons.star,
-                      color: AppColors.warning,
-                      label: 'profile.xpValue'.tr(
-                        namedArgs: {'xp': '$totalXP'},
-                      ),
-                      sublabel: 'profile.total'.tr(),
-                    ),
-                    const SizedBox(width: 8),
-                    _SummaryChip(
-                      icon: Icons.menu_book,
-                      color: primary,
-                      label: '$totalLessons',
-                      sublabel: 'profile.lessons'.tr(),
-                    ),
-                    const SizedBox(width: 8),
-                    _SummaryChip(
-                      icon: Icons.abc,
-                      color: AppColors.greenSuccessBright,
-                      label: '$totalWords',
-                      sublabel: 'profile.words'.tr(),
-                    ),
-                  ],
-                ),
-              ),
-              const Divider(height: 1),
-              // Day list
-              Expanded(
-                child: ListView.builder(
-                  controller: scrollController,
-                  padding: const EdgeInsets.symmetric(vertical: 8),
-                  itemCount: activities.length,
-                  itemBuilder: (context, index) {
-                    final a = activities[index];
-                    final isBest = a.xpEarned == maxXP && maxXP > 0;
-                    final barFraction = maxXP > 0 ? a.xpEarned / maxXP : 0.0;
-
-                    DateTime? parsedDate = DateTime.tryParse(a.date);
-                    final String dayName = parsedDate != null
-                        ? DateFormat('EEEE').format(parsedDate)
-                        : a.date;
-                    final String shortDate = parsedDate != null
-                        ? DateFormat('MMM d').format(parsedDate)
-                        : '';
-
-                    return Container(
-                      margin: const EdgeInsets.symmetric(
-                        horizontal: 16,
-                        vertical: 4,
-                      ),
-                      padding: const EdgeInsets.all(14),
-                      decoration: BoxDecoration(
-                        color: isBest
-                            ? primary.withValues(alpha: isDark ? 0.15 : 0.08)
-                            : (isDark
-                                  ? Colors.white.withValues(alpha: 0.04)
-                                  : Colors.black.withValues(alpha: 0.03)),
-                        borderRadius: BorderRadius.circular(14),
-                        border: Border.all(
-                          color: isBest
-                              ? primary.withValues(alpha: 0.4)
-                              : Colors.transparent,
-                          width: 1.5,
-                        ),
-                      ),
-                      child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
-                          Row(
-                            children: [
-                              Expanded(
-                                child: Row(
-                                  children: [
-                                    Text(
-                                      dayName,
-                                      style: const TextStyle(
-                                        fontWeight: FontWeight.w600,
-                                        fontSize: 14,
-                                      ),
-                                    ),
-                                    if (shortDate.isNotEmpty) ...[
-                                      const SizedBox(width: 6),
-                                      Text(
-                                        shortDate,
-                                        style: TextStyle(
-                                          fontSize: 12,
-                                          color: Theme.of(
-                                            context,
-                                          ).colorScheme.onSurfaceVariant,
-                                        ),
-                                      ),
-                                    ],
-                                  ],
-                                ),
-                              ),
-                              if (isBest)
-                                Container(
-                                  padding: const EdgeInsets.symmetric(
-                                    horizontal: 8,
-                                    vertical: 2,
-                                  ),
-                                  decoration: BoxDecoration(
-                                    color: AppColors.warning.withValues(
-                                      alpha: 0.15,
-                                    ),
-                                    borderRadius: BorderRadius.circular(8),
-                                    border: Border.all(
-                                      color: AppColors.warning.withValues(
-                                        alpha: 0.5,
-                                      ),
-                                    ),
-                                  ),
-                                  child: Row(
-                                    mainAxisSize: MainAxisSize.min,
-                                    children: [
-                                      Icon(
-                                        Icons.emoji_events,
-                                        size: 12,
-                                        color: AppColors.warning,
-                                      ),
-                                      SizedBox(width: 3),
-                                      Text(
-                                        'profile.bestDay'.tr(),
-                                        style: TextStyle(
-                                          fontSize: 11,
-                                          color: AppColors.warning,
-                                          fontWeight: FontWeight.w600,
-                                        ),
-                                      ),
-                                    ],
-                                  ),
-                                ),
-                            ],
-                          ),
-                          const SizedBox(height: 10),
-                          // XP bar
-                          if (a.xpEarned > 0) ...[
-                            Row(
-                              children: [
-                                Expanded(
-                                  child: ClipRRect(
-                                    borderRadius: BorderRadius.circular(4),
-                                    child: LinearProgressIndicator(
-                                      value: barFraction,
-                                      backgroundColor: primary.withValues(
-                                        alpha: 0.12,
-                                      ),
-                                      valueColor: AlwaysStoppedAnimation<Color>(
-                                        primary,
-                                      ),
-                                      minHeight: 6,
-                                    ),
-                                  ),
-                                ),
-                                const SizedBox(width: 10),
-                                Text(
-                                  'profile.xpValue'.tr(
-                                    namedArgs: {'xp': '${a.xpEarned}'},
-                                  ),
-                                  style: TextStyle(
-                                    fontSize: 13,
-                                    fontWeight: FontWeight.bold,
-                                    color: primary,
-                                  ),
-                                ),
-                              ],
-                            ),
-                            const SizedBox(height: 10),
-                          ],
-                          // Stats chips
-                          Row(
-                            children: [
-                              if (a.xpEarned == 0)
-                                Text(
-                                  'profile.noActivity'.tr(),
-                                  style: TextStyle(
-                                    fontSize: 12,
-                                    color: Theme.of(
-                                      context,
-                                    ).colorScheme.onSurfaceVariant,
-                                  ),
-                                )
-                              else ...[
-                                _MiniStat(
-                                  icon: Icons.menu_book,
-                                  color: primary,
-                                  value: 'profile.lessonsCount'.tr(
-                                    namedArgs: {
-                                      'count': '${a.lessonsCompleted}',
-                                    },
-                                  ),
-                                ),
-                                const SizedBox(width: 12),
-                                _MiniStat(
-                                  icon: Icons.abc,
-                                  color: AppColors.greenSuccessBright,
-                                  value: 'profile.wordsCount'.tr(
-                                    namedArgs: {
-                                      'count': '${a.vocabularyLearned}',
-                                    },
-                                  ),
-                                ),
-                              ],
-                            ],
-                          ),
-                        ],
-                      ),
-                    );
-                  },
-                ),
-              ),
-              // Bottom safe area
-              SizedBox(height: MediaQuery.of(context).padding.bottom + 16),
-            ],
-          ),
-        );
-      },
-    );
-  }
-}
-
-class _SummaryChip extends StatelessWidget {
-  final IconData icon;
-  final Color color;
-  final String label;
-  final String sublabel;
-
-  const _SummaryChip({
-    required this.icon,
-    required this.color,
-    required this.label,
-    required this.sublabel,
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    return Expanded(
-      child: Container(
-        padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 12),
-        decoration: BoxDecoration(
-          color: color.withValues(alpha: isDark ? 0.12 : 0.08),
-          borderRadius: BorderRadius.circular(12),
-          border: Border.all(color: color.withValues(alpha: 0.25)),
-        ),
-        child: Row(
-          children: [
-            Icon(icon, size: 16, color: color),
-            const SizedBox(width: 6),
-            Column(
-              crossAxisAlignment: CrossAxisAlignment.start,
-              children: [
-                Text(
-                  label,
-                  style: TextStyle(
-                    fontSize: 13,
-                    fontWeight: FontWeight.bold,
-                    color: color,
-                  ),
-                ),
-                Text(
-                  sublabel,
-                  style: TextStyle(
-                    fontSize: 10,
-                    color: Theme.of(context).colorScheme.onSurfaceVariant,
-                  ),
-                ),
-              ],
-            ),
-          ],
         ),
       ),
     );
   }
 }
-
-class _MiniStat extends StatelessWidget {
-  final IconData icon;
-  final Color color;
-  final String value;
-
-  const _MiniStat({
-    required this.icon,
-    required this.color,
-    required this.value,
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    return Row(
-      mainAxisSize: MainAxisSize.min,
-      children: [
-        Icon(icon, size: 14, color: color),
-        const SizedBox(width: 4),
-        Text(
-          value,
-          style: TextStyle(
-            fontSize: 12,
-            color: Theme.of(context).colorScheme.onSurfaceVariant,
-          ),
-        ),
-      ],
-    );
-  }
-}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/admin_panel_tile.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/admin_panel_tile.dart
new file mode 100644
index 00000000..1aa4be09
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/admin_panel_tile.dart
@@ -0,0 +1,87 @@
+import 'package:flutter/material.dart';
+
+class AdminPanelTile extends StatelessWidget {
+  final VoidCallback onTap;
+
+  const AdminPanelTile({super.key, required this.onTap});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+      child: Material(
+        color: Colors.transparent,
+        child: InkWell(
+          onTap: onTap,
+          borderRadius: BorderRadius.circular(16),
+          child: Ink(
+            decoration: BoxDecoration(
+              gradient: const LinearGradient(
+                colors: [Color(0xFFFF6B35), Color(0xFFFF3B00)],
+                begin: Alignment.centerLeft,
+                end: Alignment.centerRight,
+              ),
+              borderRadius: BorderRadius.circular(16),
+              boxShadow: [
+                BoxShadow(
+                  color: Colors.deepOrange.withValues(alpha: isDark ? 0.4 : 0.25),
+                  blurRadius: 12,
+                  offset: const Offset(0, 4),
+                ),
+              ],
+            ),
+            child: Padding(
+              padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 16),
+              child: Row(
+                children: [
+                  Container(
+                    padding: const EdgeInsets.all(8),
+                    decoration: BoxDecoration(
+                      color: Colors.white.withValues(alpha: 0.2),
+                      borderRadius: BorderRadius.circular(10),
+                    ),
+                    child: const Icon(
+                      Icons.admin_panel_settings_rounded,
+                      color: Colors.white,
+                      size: 22,
+                    ),
+                  ),
+                  const SizedBox(width: 14),
+                  const Expanded(
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Text(
+                          'Switch to Admin Panel',
+                          style: TextStyle(
+                            color: Colors.white,
+                            fontWeight: FontWeight.bold,
+                            fontSize: 15,
+                          ),
+                        ),
+                        SizedBox(height: 2),
+                        Text(
+                          'LexiLingo Admin mobile',
+                          style: TextStyle(
+                            color: Colors.white70,
+                            fontSize: 12,
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  const Icon(
+                    Icons.open_in_new_rounded,
+                    color: Colors.white70,
+                    size: 18,
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/learning_stats_section.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/learning_stats_section.dart
new file mode 100644
index 00000000..a74b873c
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/learning_stats_section.dart
@@ -0,0 +1,225 @@
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/profile/presentation/pages/learning_stats_pages.dart';
+import 'package:lexilingo_app/features/profile/presentation/providers/profile_provider.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_ui_components.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/skeleton_loading.dart';
+
+class LearningStatsSection extends StatelessWidget {
+  const LearningStatsSection({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<ProfileProvider>(
+      builder: (context, profileProvider, child) {
+        final isDark = Theme.of(context).brightness == Brightness.dark;
+        final primaryColor = AppColorRoles.primary(isDark);
+        // Use stats from ProfileProvider (backend API)
+        final stats = profileProvider.stats;
+        final lessonsCompleted = stats?.totalLessonsCompleted ?? 0;
+        final coursesCompleted = stats?.totalCoursesCompleted ?? 0;
+        final vocabularyMastered = stats?.totalVocabularyMastered ?? 0;
+        final testsPassed = stats?.totalTestsPassed ?? 0;
+        final avgScore = stats?.averageTestScore ?? 0.0;
+
+        // Show loading state
+        if (profileProvider.isLoadingStats && stats == null) {
+          return const _LoadingStats();
+        }
+
+        return Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Padding(
+              padding: const EdgeInsets.all(16.0),
+              child: Row(
+                children: [
+                  Icon(Icons.insights_rounded, color: primaryColor, size: 20),
+                  const SizedBox(width: 8),
+                  Text(
+                    'profile.learningStats'.tr(),
+                    style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                      fontWeight: FontWeight.bold,
+                    ),
+                  ),
+                ],
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.symmetric(horizontal: 16),
+              child: Column(
+                children: [
+                  Row(
+                    children: [
+                      Expanded(
+                        child: GlassmorphicStatCard(
+                          icon: Icons.abc,
+                          color: primaryColor,
+                          title: 'profile.lessons'.tr(),
+                          value: '$lessonsCompleted',
+                          subtitle: 'profile.completed'.tr(),
+                          valueInRightCircle: true,
+                          valueCircleSize: 40,
+                          valueCircleFontSize: 18,
+                          isAction: true,
+                          onTap: () => Navigator.push(
+                            context,
+                            MaterialPageRoute(
+                              builder: (_) => const LearningLessonsStatsPage(),
+                            ),
+                          ),
+                          iconBoxSize: 28,
+                          iconSize: 14,
+                          titleFontSize: 13,
+                          subtitleFontSize: 11,
+                          contentPadding: const EdgeInsets.symmetric(
+                            horizontal: 12,
+                            vertical: 10,
+                          ),
+                        ),
+                      ),
+                      const SizedBox(width: 10),
+                      Expanded(
+                        child: GlassmorphicStatCard(
+                          icon: Icons.school,
+                          color: primaryColor,
+                          title: 'profile.courses'.tr(),
+                          value: '$coursesCompleted',
+                          subtitle: 'profile.finished'.tr(),
+                          valueInRightCircle: true,
+                          valueCircleSize: 40,
+                          valueCircleFontSize: 18,
+                          isAction: true,
+                          onTap: () => Navigator.push(
+                            context,
+                            MaterialPageRoute(
+                              builder: (_) => const LearningCoursesStatsPage(),
+                            ),
+                          ),
+                          iconBoxSize: 28,
+                          iconSize: 14,
+                          titleFontSize: 13,
+                          subtitleFontSize: 11,
+                          contentPadding: const EdgeInsets.symmetric(
+                            horizontal: 12,
+                            vertical: 10,
+                          ),
+                        ),
+                      ),
+                    ],
+                  ),
+                  const SizedBox(height: 10),
+                  Row(
+                    children: [
+                      Expanded(
+                        child: GlassmorphicStatCard(
+                          icon: Icons.auto_stories,
+                          color: primaryColor,
+                          title: 'profile.vocabulary'.tr(),
+                          value: '$vocabularyMastered',
+                          subtitle: 'profile.mastered'.tr(),
+                          valueInRightCircle: true,
+                          valueCircleSize: 40,
+                          valueCircleFontSize: 18,
+                          isAction: true,
+                          onTap: () => Navigator.push(
+                            context,
+                            MaterialPageRoute(
+                              builder: (_) =>
+                                  const LearningVocabularyStatsPage(),
+                            ),
+                          ),
+                          iconBoxSize: 28,
+                          iconSize: 14,
+                          titleFontSize: 13,
+                          subtitleFontSize: 11,
+                          contentPadding: const EdgeInsets.symmetric(
+                            horizontal: 12,
+                            vertical: 10,
+                          ),
+                        ),
+                      ),
+                      const SizedBox(width: 10),
+                      Expanded(
+                        child: GlassmorphicStatCard(
+                          icon: Icons.quiz,
+                          color: primaryColor,
+                          title: 'profile.tests'.tr(),
+                          value: '$testsPassed',
+                          subtitle: avgScore > 0
+                              ? 'profile.averagePercent'.tr(
+                                  namedArgs: {
+                                    'percent': avgScore.toStringAsFixed(0),
+                                  },
+                                )
+                              : 'profile.passed'.tr(),
+                          valueInRightCircle: true,
+                          valueCircleSize: 40,
+                          valueCircleFontSize: 18,
+                          isAction: true,
+                          onTap: () => Navigator.push(
+                            context,
+                            MaterialPageRoute(
+                              builder: (_) => const LearningTestsStatsPage(),
+                            ),
+                          ),
+                          iconBoxSize: 28,
+                          iconSize: 14,
+                          titleFontSize: 13,
+                          subtitleFontSize: 11,
+                          contentPadding: const EdgeInsets.symmetric(
+                            horizontal: 12,
+                            vertical: 10,
+                          ),
+                        ),
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+            ),
+          ],
+        );
+      },
+    );
+  }
+}
+
+class _LoadingStats extends StatelessWidget {
+  const _LoadingStats();
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Padding(
+          padding: const EdgeInsets.all(16.0),
+          child: Text(
+            'profile.learningStats'.tr(),
+            style: Theme.of(
+              context,
+            ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
+          ),
+        ),
+        GridView.count(
+          crossAxisCount: 2,
+          shrinkWrap: true,
+          physics: const NeverScrollableScrollPhysics(),
+          padding: const EdgeInsets.symmetric(horizontal: 16),
+          crossAxisSpacing: 12,
+          mainAxisSpacing: 12,
+          childAspectRatio: 1.15,
+          children: List.generate(
+            4,
+            (index) => ShimmerContainer(
+              child: SkeletonBox(height: double.infinity, borderRadius: 12),
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/level_progress_card.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/level_progress_card.dart
new file mode 100644
index 00000000..9ed8b637
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/level_progress_card.dart
@@ -0,0 +1,94 @@
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/level/level.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_ui_components.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+class ProfileLevelProgressCard extends StatelessWidget {
+  const ProfileLevelProgressCard({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    return Consumer<LevelProvider>(
+      builder: (context, levelProvider, child) {
+        final level = levelProvider.displayLevel;
+        final xpIn = levelProvider.displayXpInLevel;
+        final xpFor = levelProvider.displayXpForNextLevel;
+        final progress = levelProvider.displayLevelProgress;
+
+        return GlassmorphicContainer(
+          child: Column(
+            children: [
+              Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  Text(
+                    'profile.levelRange'.tr(
+                      namedArgs: {
+                        'level': '$level',
+                        'nextLevel': '${level + 1}',
+                      },
+                    ),
+                    style: const TextStyle(fontWeight: FontWeight.w500),
+                  ),
+                  Text(
+                    'profile.xpProgress'.tr(
+                      namedArgs: {'current': '$xpIn', 'total': '$xpFor'},
+                    ),
+                    style: const TextStyle(fontSize: 14),
+                  ),
+                ],
+              ),
+              const SizedBox(height: 12),
+              ClipRRect(
+                borderRadius: BorderRadius.circular(6),
+                child: LinearProgressIndicator(
+                  value: progress,
+                  backgroundColor: AppColorRoles.primary(
+                    isDark,
+                  ).withValues(alpha: 0.18),
+                  valueColor: AlwaysStoppedAnimation<Color>(
+                    AppColorRoles.primary(isDark),
+                  ),
+                  minHeight: 12,
+                ),
+              ),
+              const SizedBox(height: 12),
+              Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  Text(
+                    'profile.xpToNextLevel'.tr(
+                      namedArgs: {
+                        'xp': '${xpFor - xpIn}',
+                        'level': '${level + 1}',
+                      },
+                    ),
+                    style: TextStyle(
+                      color: Theme.of(context).colorScheme.onSurfaceVariant,
+                      fontSize: 12,
+                    ),
+                  ),
+                  Text(
+                    'profile.percentComplete'.tr(
+                      namedArgs: {
+                        'percent': (progress * 100).toStringAsFixed(0),
+                      },
+                    ),
+                    style: TextStyle(
+                      color: AppColorRoles.primary(isDark),
+                      fontSize: 12,
+                      fontWeight: FontWeight.bold,
+                    ),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        );
+      },
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/profile_header.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/profile_header.dart
new file mode 100644
index 00000000..6cc8822a
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/profile_header.dart
@@ -0,0 +1,543 @@
+import 'dart:ui';
+
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/gamification/gamification.dart';
+import 'package:lexilingo_app/features/level/level.dart';
+import 'package:lexilingo_app/features/profile/presentation/pages/edit_profile_screen.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_page/social_stats_row.dart';
+import 'package:lexilingo_app/core/widgets/glassmorphic_components.dart' as glass;
+import 'package:lexilingo_app/core/widgets/network_avatar_image.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+String formatMemberSince(BuildContext context, DateTime? createdAt) {
+  if (createdAt == null) return 'profile.member'.tr();
+  return 'profile.memberSince'.tr(
+    namedArgs: {'date': DateFormat('MMM yyyy').format(createdAt)},
+  );
+}
+
+IconData tierIcon(String tierCode) {
+  switch (tierCode) {
+    case 'A1':
+      return Icons.eco;
+    case 'A2':
+      return Icons.spa;
+    case 'B1':
+      return Icons.bolt;
+    case 'B2':
+      return Icons.rocket_launch;
+    case 'C1':
+      return Icons.workspace_premium;
+    case 'C2':
+      return Icons.diamond;
+    default:
+      return Icons.star;
+  }
+}
+
+Color tierColor(BuildContext context, String tierCode) {
+  final isDark = Theme.of(context).brightness == Brightness.dark;
+  switch (tierCode) {
+    case 'A1':
+      return AppColors.greenSuccessBright;
+    case 'A2':
+      return AppColors.teal;
+    case 'B1':
+      return AppColorRoles.primary(isDark);
+    case 'B2':
+      return AppColorRoles.primaryDeep(isDark);
+    case 'C1':
+      return AppColors.purple;
+    case 'C2':
+      return AppColors.warning;
+    default:
+      return AppColorRoles.primary(isDark);
+  }
+}
+
+class ProfileHeader extends StatelessWidget {
+  final dynamic user;
+  final VoidCallback onProfileEdited;
+
+  const ProfileHeader({
+    super.key,
+    required this.user,
+    required this.onProfileEdited,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+    return Consumer<LevelProvider>(
+      builder: (context, levelProvider, child) {
+        // Use numeric level progress, not CEFR-based
+        final progress = levelProvider.displayLevelProgress;
+
+        return Container(
+          margin: const EdgeInsets.all(16),
+          child: Stack(
+            children: [
+              // Glassmorphic Background Card
+              ClipRRect(
+                borderRadius: BorderRadius.circular(24),
+                child: BackdropFilter(
+                  filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
+                  child: Container(
+                    width: double.infinity,
+                    padding: const EdgeInsets.all(24),
+                    decoration: BoxDecoration(
+                      gradient: LinearGradient(
+                        begin: Alignment.topLeft,
+                        end: Alignment.bottomRight,
+                        colors: [
+                          (isDark ? accent : AppColors.primary).withValues(
+                            alpha: 0.15,
+                          ),
+                          (isDark ? accent : AppColors.primary).withValues(
+                            alpha: 0.1,
+                          ),
+                          AppColors.surfaceLight.withValues(alpha: 0.05),
+                        ],
+                      ),
+                      borderRadius: BorderRadius.circular(24),
+                      border: Border.all(
+                        color: Theme.of(
+                          context,
+                        ).colorScheme.surface.withValues(alpha: 0.2),
+                        width: 1.5,
+                      ),
+                      boxShadow: [
+                        BoxShadow(
+                          color: (isDark ? accent : AppColors.primary)
+                              .withValues(alpha: 0.12),
+                          blurRadius: 20,
+                          offset: const Offset(0, 10),
+                        ),
+                      ],
+                    ),
+                    child: Column(
+                      children: [
+                        // Avatar with animated progress ring
+                        Stack(
+                          alignment: Alignment.center,
+                          children: [
+                            // Progress Ring
+                            glass.AnimatedProgressRing(
+                              progress: progress,
+                              size: 140,
+                              strokeWidth: 6,
+                              gradientColors: [
+                                isDark ? accent : AppColors.primary,
+                                isDark ? accent : AppColors.primary,
+                                AppColors.purple,
+                              ],
+                              child: Container(
+                                width: 120,
+                                height: 120,
+                                decoration: BoxDecoration(
+                                  shape: BoxShape.circle,
+                                  border: Border.all(
+                                    color: Theme.of(context).colorScheme.surface
+                                        .withValues(alpha: 0.5),
+                                    width: 3,
+                                  ),
+                                  boxShadow: [
+                                    BoxShadow(
+                                      color:
+                                          (isDark ? accent : AppColors.primary)
+                                              .withValues(alpha: 0.3),
+                                      blurRadius: 20,
+                                      spreadRadius: 5,
+                                    ),
+                                  ],
+                                ),
+                                child: ClipOval(
+                                  child: NetworkAvatarImage(
+                                    imageUrl: user?.avatarUrl,
+                                    fit: BoxFit.cover,
+                                    width: 120,
+                                    height: 120,
+                                    fallback: Container(
+                                      color:
+                                          (isDark ? accent : AppColors.primary)
+                                              .withValues(alpha: 0.2),
+                                      child: Icon(
+                                        Icons.person,
+                                        size: 60,
+                                        color: isDark
+                                            ? accent
+                                            : AppColors.primary,
+                                      ),
+                                    ),
+                                  ),
+                                ),
+                              ),
+                            ),
+                            // Verified Badge
+                            if (user?.isVerified == true)
+                              Positioned(
+                                bottom: 10,
+                                right: 10,
+                                child: Container(
+                                  padding: const EdgeInsets.all(6),
+                                  decoration: BoxDecoration(
+                                    gradient: LinearGradient(
+                                      colors: [
+                                        isDark ? accent : AppColors.primary,
+                                        isDark ? accent : AppColors.primary,
+                                      ],
+                                    ),
+                                    shape: BoxShape.circle,
+                                    border: Border.all(
+                                      color: AppColors.surfaceLight,
+                                      width: 2,
+                                    ),
+                                    boxShadow: [
+                                      BoxShadow(
+                                        color:
+                                            (isDark
+                                                    ? accent
+                                                    : AppColors.primary)
+                                                .withValues(alpha: 0.5),
+                                        blurRadius: 8,
+                                      ),
+                                    ],
+                                  ),
+                                  child: Icon(
+                                    Icons.verified,
+                                    color: AppColors.surfaceLight,
+                                    size: 16,
+                                  ),
+                                ),
+                              ),
+                          ],
+                        ),
+                        const SizedBox(height: 20),
+                        // User Name
+                        Text(
+                          user?.displayName ?? 'profile.guestUser'.tr(),
+                          textAlign: TextAlign.center,
+                          style: Theme.of(context).textTheme.headlineSmall
+                              ?.copyWith(
+                                fontWeight: FontWeight.bold,
+                                letterSpacing: -0.5,
+                              ),
+                        ),
+                        const SizedBox(height: 6),
+                        // Email
+                        if (user?.email != null)
+                          Text(
+                            user.email,
+                            style: const TextStyle(
+                              color: AppColors.grey600,
+                              fontSize: 13,
+                            ),
+                          ),
+                        const SizedBox(height: 12),
+                        // Level Badge + CEFR Proficiency Badge + Rank Badge
+                        Consumer<LevelProvider>(
+                          builder: (_, lp, __) {
+                            final rankData = rankVisualDataFor(lp.rank);
+                            final isMasterRank = lp.rank == 'master';
+                            return Wrap(
+                              spacing: 8,
+                              runSpacing: 8,
+                              alignment: WrapAlignment.center,
+                              children: [
+                                // Numeric Level badge
+                                Container(
+                                  padding: const EdgeInsets.symmetric(
+                                    horizontal: 16,
+                                    vertical: 8,
+                                  ),
+                                  decoration: BoxDecoration(
+                                    gradient: LinearGradient(
+                                      colors: AppColorRoles.primaryGradient(
+                                        isDark,
+                                      ),
+                                    ),
+                                    borderRadius: BorderRadius.circular(20),
+                                    boxShadow: [
+                                      BoxShadow(
+                                        color: (isDark
+                                                ? accent
+                                                : AppColors.primary)
+                                            .withValues(alpha: 0.4),
+                                        blurRadius: 8,
+                                        offset: const Offset(0, 4),
+                                      ),
+                                    ],
+                                  ),
+                                  child: Row(
+                                    mainAxisSize: MainAxisSize.min,
+                                    children: [
+                                      Icon(
+                                        Icons.workspace_premium_rounded,
+                                        color: AppColors.surfaceLight,
+                                        size: 16,
+                                      ),
+                                      const SizedBox(width: 6),
+                                      Text(
+                                        'profile.level'.tr(
+                                          namedArgs: {
+                                            'level': '${lp.displayLevel}',
+                                          },
+                                        ),
+                                        style: TextStyle(
+                                          color: AppColors.surfaceLight,
+                                          fontWeight: FontWeight.bold,
+                                          fontSize: 13,
+                                        ),
+                                      ),
+                                    ],
+                                  ),
+                                ),
+                                // CEFR Proficiency Badge
+                                Container(
+                                  padding: const EdgeInsets.symmetric(
+                                    horizontal: 12,
+                                    vertical: 8,
+                                  ),
+                                  decoration: BoxDecoration(
+                                    color: tierColor(
+                                      context,
+                                      lp.proficiencyLevel,
+                                    ).withValues(alpha: 0.12),
+                                    borderRadius: BorderRadius.circular(20),
+                                    border: Border.all(
+                                      color: tierColor(
+                                        context,
+                                        lp.proficiencyLevel,
+                                      ).withValues(alpha: 0.5),
+                                    ),
+                                  ),
+                                  child: Row(
+                                    mainAxisSize: MainAxisSize.min,
+                                    children: [
+                                      Icon(
+                                        tierIcon(lp.proficiencyLevel),
+                                        size: 14,
+                                        color: tierColor(
+                                          context,
+                                          lp.proficiencyLevel,
+                                        ),
+                                      ),
+                                      const SizedBox(width: 4),
+                                      Text(
+                                        lp.proficiencyLevel,
+                                        style: TextStyle(
+                                          color: tierColor(
+                                            context,
+                                            lp.proficiencyLevel,
+                                          ),
+                                          fontWeight: FontWeight.bold,
+                                          fontSize: 13,
+                                        ),
+                                      ),
+                                      const SizedBox(width: 4),
+                                      Text(
+                                        '·',
+                                        style: TextStyle(
+                                          color: tierColor(
+                                            context,
+                                            lp.proficiencyLevel,
+                                          ).withValues(alpha: 0.6),
+                                          fontSize: 13,
+                                        ),
+                                      ),
+                                      const SizedBox(width: 4),
+                                      Text(
+                                        lp.proficiencyName,
+                                        style: TextStyle(
+                                          color: tierColor(
+                                            context,
+                                            lp.proficiencyLevel,
+                                          ),
+                                          fontWeight: FontWeight.w500,
+                                          fontSize: 12,
+                                        ),
+                                      ),
+                                    ],
+                                  ),
+                                ),
+                                // League Rank Badge
+                                GestureDetector(
+                                  onTap: () => Navigator.push(
+                                    context,
+                                    MaterialPageRoute(
+                                      builder: (_) =>
+                                          const LeaderboardScreen(),
+                                    ),
+                                  ),
+                                  child: isMasterRank
+                                      ? ShaderMask(
+                                          shaderCallback: (bounds) =>
+                                              const LinearGradient(
+                                                colors: [
+                                                  Color(0xFF5AB6FF),
+                                                  Color(0xFFFFD64F),
+                                                ],
+                                                begin: Alignment.topLeft,
+                                                end: Alignment.bottomRight,
+                                              ).createShader(bounds),
+                                          child: Container(
+                                            padding: const EdgeInsets.symmetric(
+                                              horizontal: 10,
+                                              vertical: 6,
+                                            ),
+                                            decoration: BoxDecoration(
+                                              color: Colors.white.withValues(
+                                                alpha: 0.12,
+                                              ),
+                                              borderRadius:
+                                                  BorderRadius.circular(20),
+                                              border: Border.all(
+                                                color: Colors.white.withValues(
+                                                  alpha: 0.4,
+                                                ),
+                                              ),
+                                            ),
+                                            child: Row(
+                                              mainAxisSize: MainAxisSize.min,
+                                              children: [
+                                                RankAssetIcon(
+                                                  rank: lp.rank,
+                                                  size: 16,
+                                                  decorated: false,
+                                                ),
+                                                const SizedBox(width: 5),
+                                                Text(
+                                                  lp.rankName,
+                                                  style: const TextStyle(
+                                                    color: Colors.white,
+                                                    fontWeight: FontWeight.bold,
+                                                    fontSize: 12,
+                                                  ),
+                                                ),
+                                              ],
+                                            ),
+                                          ),
+                                        )
+                                      : Container(
+                                          padding: const EdgeInsets.symmetric(
+                                            horizontal: 10,
+                                            vertical: 6,
+                                          ),
+                                          decoration: BoxDecoration(
+                                            color: rankData.color.withValues(
+                                              alpha: 0.1,
+                                            ),
+                                            borderRadius:
+                                                BorderRadius.circular(20),
+                                            border: Border.all(
+                                              color: rankData.color.withValues(
+                                                alpha: 0.4,
+                                              ),
+                                            ),
+                                          ),
+                                          child: Row(
+                                            mainAxisSize: MainAxisSize.min,
+                                            children: [
+                                              RankAssetIcon(
+                                                rank: lp.rank,
+                                                size: 16,
+                                                decorated: false,
+                                              ),
+                                              const SizedBox(width: 5),
+                                              Text(
+                                                lp.rankName,
+                                                style: TextStyle(
+                                                  color: rankData.color,
+                                                  fontWeight: FontWeight.bold,
+                                                  fontSize: 12,
+                                                ),
+                                              ),
+                                            ],
+                                          ),
+                                        ),
+                                ),
+                              ],
+                            );
+                          },
+                        ),
+                        const SizedBox(height: 8),
+                        // Member Since
+                        Text(
+                          formatMemberSince(context, user?.createdAt),
+                          style: const TextStyle(
+                            color: AppColors.grey600,
+                            fontSize: 12,
+                          ),
+                        ),
+                        const SizedBox(height: 12),
+                        // Edit Profile Button
+                        GestureDetector(
+                          onTap: () async {
+                            final result = await Navigator.push(
+                              context,
+                              MaterialPageRoute(
+                                builder: (_) => const EditProfileScreen(),
+                              ),
+                            );
+                            if (result == true) {
+                              onProfileEdited(); // Refresh after edit
+                            }
+                          },
+                          child: Container(
+                            padding: const EdgeInsets.symmetric(
+                              horizontal: 20,
+                              vertical: 8,
+                            ),
+                            decoration: BoxDecoration(
+                              gradient: LinearGradient(
+                                colors: AppColorRoles.primaryGradient(isDark),
+                              ),
+                              borderRadius: BorderRadius.circular(20),
+                              boxShadow: [
+                                BoxShadow(
+                                  color: (isDark ? accent : AppColors.primary)
+                                      .withValues(alpha: 0.3),
+                                  blurRadius: 8,
+                                  offset: Offset(0, 4),
+                                ),
+                              ],
+                            ),
+                            child: Row(
+                              mainAxisSize: MainAxisSize.min,
+                              children: [
+                                Icon(
+                                  Icons.edit,
+                                  color: AppColors.surfaceLight,
+                                  size: 14,
+                                ),
+                                SizedBox(width: 6),
+                                Text(
+                                  'profile.editProfile'.tr(),
+                                  style: TextStyle(
+                                    color: AppColors.surfaceLight,
+                                    fontWeight: FontWeight.bold,
+                                    fontSize: 13,
+                                  ),
+                                ),
+                              ],
+                            ),
+                          ),
+                        ),
+                        const SizedBox(height: 20),
+                        // Social Stats Row
+                        const SocialStatsRow(),
+                      ],
+                    ),
+                  ),
+                ),
+              ),
+            ],
+          ),
+        );
+      },
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/quick_actions_row.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/quick_actions_row.dart
new file mode 100644
index 00000000..8bd1f71c
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/quick_actions_row.dart
@@ -0,0 +1,131 @@
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/gamification/gamification.dart';
+import 'package:lexilingo_app/features/progress/presentation/screens/my_progress_screen.dart';
+import 'package:lexilingo_app/features/social/social.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+/// Quick Actions Grid - Navigate to new gamification/social features
+class QuickActionsRow extends StatelessWidget {
+  const QuickActionsRow({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+      child: Row(
+        children: [
+          _QuickActionButton(
+            icon: Icons.store,
+            label: 'profile.shop'.tr(),
+            color: AppColors.orange,
+            gradient: AppColors.warmGradient,
+            onTap: () => Navigator.push(
+              context,
+              MaterialPageRoute(builder: (_) => const ShopScreen()),
+            ),
+          ),
+          const SizedBox(width: 12),
+          _QuickActionButton(
+            icon: Icons.leaderboard,
+            label: 'profile.ranks'.tr(),
+            color: AppColors.greenSuccess,
+            gradient: AppColors.successGradient,
+            onTap: () => Navigator.push(
+              context,
+              MaterialPageRoute(builder: (_) => const LeaderboardScreen()),
+            ),
+          ),
+          const SizedBox(width: 12),
+          _QuickActionButton(
+            icon: Icons.people,
+            label: 'profile.friends'.tr(),
+            color: AppColorRoles.primary(
+              Theme.of(context).brightness == Brightness.dark,
+            ),
+            gradient: Theme.of(context).brightness == Brightness.dark
+                ? AppColors.primaryGradientDark
+                : AppColors.indigoGradient,
+            onTap: () => Navigator.push(
+              context,
+              MaterialPageRoute(builder: (_) => const SocialScreen()),
+            ),
+          ),
+          const SizedBox(width: 12),
+          _QuickActionButton(
+            icon: Icons.insights_rounded,
+            label: 'profile.progress'.tr(),
+            color: AppColors.purple,
+            gradient: AppColors.purpleGradient,
+            onTap: () => Navigator.push(
+              context,
+              MaterialPageRoute(builder: (_) => const MyProgressScreen()),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _QuickActionButton extends StatelessWidget {
+  final IconData icon;
+  final String label;
+  final Color color;
+  final List<Color> gradient;
+  final VoidCallback onTap;
+
+  const _QuickActionButton({
+    required this.icon,
+    required this.label,
+    required this.color,
+    required this.gradient,
+    required this.onTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Expanded(
+      child: GestureDetector(
+        onTap: onTap,
+        child: Container(
+          padding: const EdgeInsets.symmetric(vertical: 12),
+          decoration: BoxDecoration(
+            gradient: LinearGradient(
+              colors: gradient,
+              begin: Alignment.topLeft,
+              end: Alignment.bottomRight,
+            ),
+            borderRadius: BorderRadius.circular(12),
+            boxShadow: [
+              BoxShadow(
+                color: color.withValues(alpha: 0.3),
+                blurRadius: 8,
+                offset: Offset(0, 4),
+              ),
+            ],
+          ),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Icon(
+                icon,
+                color: Theme.of(context).colorScheme.surface,
+                size: 24,
+              ),
+              const SizedBox(height: 4),
+              Text(
+                label,
+                style: TextStyle(
+                  color: Theme.of(context).colorScheme.surface,
+                  fontSize: 11,
+                  fontWeight: FontWeight.w600,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/recent_badges_section.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/recent_badges_section.dart
new file mode 100644
index 00000000..db077da3
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/recent_badges_section.dart
@@ -0,0 +1,275 @@
+import 'dart:ui';
+
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/achievements/data/badge_asset_mapper.dart';
+import 'package:lexilingo_app/features/achievements/domain/entities/achievement_entity.dart';
+import 'package:lexilingo_app/features/achievements/presentation/screens/achievements_screen.dart';
+import 'package:lexilingo_app/features/achievements/presentation/widgets/achievement_widgets.dart';
+import 'package:lexilingo_app/features/profile/presentation/providers/profile_provider.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/skeleton_loading.dart';
+
+class RecentBadgesSection extends StatefulWidget {
+  const RecentBadgesSection({super.key});
+
+  @override
+  State<RecentBadgesSection> createState() => _RecentBadgesSectionState();
+}
+
+class _RecentBadgesSectionState extends State<RecentBadgesSection>
+    with SingleTickerProviderStateMixin {
+  late final AnimationController _badgeShineController;
+
+  @override
+  void initState() {
+    super.initState();
+    _badgeShineController = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 3000),
+    )..repeat();
+  }
+
+  @override
+  void dispose() {
+    _badgeShineController.dispose();
+    super.dispose();
+  }
+
+  bool _hasRenderableBadgeImage(UserAchievementEntity badge) {
+    final achievement = badge.achievement;
+
+    if (achievement.category.toLowerCase() == 'xp') {
+      return false;
+    }
+
+    final networkBadge = achievement.badgeIcon?.trim();
+    final networkBadgeUri = networkBadge != null && networkBadge.isNotEmpty
+        ? Uri.tryParse(networkBadge)
+        : null;
+    final hasValidNetworkBadge =
+        networkBadgeUri != null &&
+        (networkBadgeUri.scheme == 'http' ||
+            networkBadgeUri.scheme == 'https') &&
+        networkBadgeUri.host.isNotEmpty;
+    if (hasValidNetworkBadge) {
+      return true;
+    }
+
+    final lookupKey = (achievement.slug ?? achievement.id).trim();
+    if (lookupKey.isEmpty) {
+      return false;
+    }
+
+    return BadgeAssetMapper.hasRenderableBadge(lookupKey);
+  }
+
+  /// Build empty badges placeholder
+  Widget _buildEmptyBadges() {
+    return Center(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          const Icon(
+            Icons.emoji_events_outlined,
+            size: 40,
+            color: AppColors.grey500,
+          ),
+          const SizedBox(height: 8),
+          Text(
+            'profile.completeLessonsToEarnBadges'.tr(),
+            style: const TextStyle(color: AppColors.grey600, fontSize: 12),
+          ),
+        ],
+      ),
+    );
+  }
+
+  /// Build badge item from UserAchievementEntity
+  Widget _buildBadgeItemFromEntity(UserAchievementEntity badge) {
+    final achievement = badge.achievement;
+    const badgeSize = 64.0;
+    final badgeMask = _buildBadgeShineMask(badge, badgeSize);
+
+    return Tooltip(
+      message: '${achievement.name}\n${badge.unlockedTimeAgo}',
+      child: Column(
+        children: [
+          SizedBox(
+            width: badgeSize,
+            height: badgeSize,
+            child: Stack(
+              alignment: Alignment.center,
+              children: [
+                AchievementBadge(
+                  achievement: achievement,
+                  isUnlocked: true,
+                  size: badgeSize,
+                ),
+                Positioned.fill(
+                  child: IgnorePointer(
+                    child: AnimatedBuilder(
+                      animation: _badgeShineController,
+                      builder: (context, child) {
+                        // Smaller sweep portion => longer idle pause per cycle.
+                        const sweepPortion = 0.62;
+                        final progress = _badgeShineController.value;
+                        final isSweeping = progress < sweepPortion;
+                        final sweepT = isSweeping
+                            ? Curves.easeInOut.transform(
+                                progress / sweepPortion,
+                              )
+                            : 1.0;
+                        final position = isSweeping
+                            ? lerpDouble(-1.6, 1.6, sweepT)!
+                            : 2.4;
+
+                        return ShaderMask(
+                          // Apply shine only where the badge image has alpha.
+                          blendMode: BlendMode.srcIn,
+                          shaderCallback: (bounds) {
+                            return LinearGradient(
+                              begin: Alignment(position - 0.45, -1.0),
+                              end: Alignment(position + 0.45, 1.0),
+                              colors: [
+                                AppColors.surfaceLight.withValues(alpha: 0),
+                                AppColors.surfaceLight.withValues(alpha: 0.06),
+                                AppColors.surfaceLight.withValues(alpha: 0.56),
+                                AppColors.surfaceLight.withValues(alpha: 0.06),
+                                AppColors.surfaceLight.withValues(alpha: 0),
+                              ],
+                              stops: const [0.0, 0.42, 0.5, 0.58, 1.0],
+                            ).createShader(bounds);
+                          },
+                          child: child,
+                        );
+                      },
+                      child: badgeMask,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+          ),
+          const SizedBox(height: 8),
+          Text(
+            achievement.name,
+            style: const TextStyle(fontSize: 10, fontWeight: FontWeight.w500),
+            overflow: TextOverflow.ellipsis,
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildBadgeShineMask(UserAchievementEntity badge, double badgeSize) {
+    final achievement = badge.achievement;
+
+    final networkBadge = achievement.badgeIcon?.trim();
+    final networkBadgeUri = networkBadge != null && networkBadge.isNotEmpty
+        ? Uri.tryParse(networkBadge)
+        : null;
+    final hasValidNetworkBadge =
+        networkBadgeUri != null &&
+        (networkBadgeUri.scheme == 'http' ||
+            networkBadgeUri.scheme == 'https') &&
+        networkBadgeUri.host.isNotEmpty;
+
+    if (hasValidNetworkBadge) {
+      return ClipOval(
+        child: Image.network(
+          networkBadge!,
+          width: badgeSize,
+          height: badgeSize,
+          fit: BoxFit.cover,
+          errorBuilder: (_, __, ___) => const SizedBox.shrink(),
+        ),
+      );
+    }
+
+    final lookupKey = (achievement.slug ?? achievement.id).trim();
+    final assetPath = BadgeAssetMapper.getBadgeAsset(lookupKey);
+    if (assetPath != null) {
+      return ClipOval(
+        child: Image.asset(
+          assetPath,
+          width: badgeSize,
+          height: badgeSize,
+          fit: BoxFit.cover,
+          errorBuilder: (_, __, ___) => const SizedBox.shrink(),
+        ),
+      );
+    }
+
+    return const SizedBox.shrink();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<ProfileProvider>(
+      builder: (context, provider, child) {
+        final badges = provider.recentBadges;
+        final isLoading = provider.isLoadingBadges;
+        final visibleBadges = badges.where(_hasRenderableBadgeImage).toList();
+
+        return Column(
+          children: [
+            Padding(
+              padding: const EdgeInsets.all(16.0),
+              child: Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  Text(
+                    'profile.recentBadges'.tr(),
+                    style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                      fontWeight: FontWeight.bold,
+                    ),
+                  ),
+                  TextButton(
+                    onPressed: () {
+                      Navigator.push(
+                        context,
+                        MaterialPageRoute(
+                          builder: (_) => const AchievementsScreen(),
+                        ),
+                      );
+                    },
+                    child: Text('achievements.viewAll'.tr()),
+                  ),
+                ],
+              ),
+            ),
+            SizedBox(
+              height: 100,
+              child: isLoading
+                  ? ShimmerContainer(
+                      child: ListView.separated(
+                        scrollDirection: Axis.horizontal,
+                        padding: const EdgeInsets.symmetric(horizontal: 16),
+                        itemCount: 4,
+                        separatorBuilder: (_, __) => const SizedBox(width: 16),
+                        itemBuilder: (context, index) {
+                          return const SkeletonCircle(size: 80);
+                        },
+                      ),
+                    )
+                  : visibleBadges.isEmpty
+                  ? _buildEmptyBadges()
+                  : ListView.separated(
+                      scrollDirection: Axis.horizontal,
+                      padding: const EdgeInsets.symmetric(horizontal: 16),
+                      itemCount: visibleBadges.length,
+                      separatorBuilder: (_, __) => const SizedBox(width: 16),
+                      itemBuilder: (context, index) {
+                        final badge = visibleBadges[index];
+                        return _buildBadgeItemFromEntity(badge);
+                      },
+                    ),
+            ),
+          ],
+        );
+      },
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/social_stats_row.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/social_stats_row.dart
new file mode 100644
index 00000000..81160d2d
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/social_stats_row.dart
@@ -0,0 +1,56 @@
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/profile/presentation/providers/profile_provider.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_ui_components.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+/// Social stats row showing XP, followers, following
+class SocialStatsRow extends StatelessWidget {
+  const SocialStatsRow({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<ProfileProvider>(
+      builder: (context, profileProvider, _) {
+        final stats = profileProvider.stats;
+
+        return Row(
+          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+          children: [
+            AnimatedSocialStat(
+              value: '${stats?.totalVocabularyMastered ?? 0}',
+              label: 'profile.words'.tr(),
+              icon: Icons.spellcheck_rounded,
+              color: AppColors.greenSuccessBright,
+            ),
+            Container(
+              height: 40,
+              width: 1,
+              color: AppColors.grey400.withValues(alpha: 0.5),
+            ),
+            AnimatedSocialStat(
+              value: '${stats?.totalLessonsCompleted ?? 0}',
+              label: 'profile.lessons'.tr(),
+              icon: Icons.menu_book,
+              color: AppColorRoles.primary(
+                Theme.of(context).brightness == Brightness.dark,
+              ),
+            ),
+            Container(
+              height: 40,
+              width: 1,
+              color: AppColors.grey400.withValues(alpha: 0.5),
+            ),
+            AnimatedSocialStat(
+              value: '${stats?.currentStreak ?? 0}',
+              label: 'profile.dayStreak'.tr(),
+              icon: Icons.local_fire_department,
+              color: AppColors.dangerGradient[0],
+            ),
+          ],
+        );
+      },
+    );
+  }
+}
diff --git a/flutter-app/lib/features/profile/presentation/widgets/profile_page/weekly_activity_section.dart b/flutter-app/lib/features/profile/presentation/widgets/profile_page/weekly_activity_section.dart
new file mode 100644
index 00000000..a8f56c2f
--- /dev/null
+++ b/flutter-app/lib/features/profile/presentation/widgets/profile_page/weekly_activity_section.dart
@@ -0,0 +1,710 @@
+import 'package:flutter/material.dart';
+import 'package:easy_localization/easy_localization.dart';
+import 'package:lexilingo_app/features/profile/presentation/providers/profile_provider.dart';
+import 'package:lexilingo_app/features/profile/presentation/widgets/profile_ui_components.dart';
+import 'package:lexilingo_app/features/user/domain/entities/weekly_activity_entity.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/skeleton_loading.dart';
+
+void _showWeeklyActivityDetail(
+  BuildContext context,
+  List<WeeklyActivityEntity> activities,
+) {
+  showModalBottomSheet(
+    context: context,
+    isScrollControlled: true,
+    backgroundColor: Colors.transparent,
+    builder: (_) => _WeeklyActivityDetailSheet(activities: activities),
+  );
+}
+
+class WeeklyActivitySection extends StatelessWidget {
+  const WeeklyActivitySection({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<ProfileProvider>(
+      builder: (context, profileProvider, child) {
+        final isDark = Theme.of(context).brightness == Brightness.dark;
+        final activities = profileProvider.weeklyActivity;
+        final isLoading = profileProvider.isLoadingActivity;
+        final activityError = profileProvider.activityError;
+
+        return Column(
+          children: [
+            Padding(
+              padding: const EdgeInsets.symmetric(
+                horizontal: 16.0,
+                vertical: 16,
+              ),
+              child: Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  Text(
+                    'profile.weeklyActivity'.tr(),
+                    style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
+                  ),
+                  GestureDetector(
+                    onTap: activities.isNotEmpty
+                        ? () => _showWeeklyActivityDetail(context, activities)
+                        : null,
+                    child: Row(
+                      mainAxisSize: MainAxisSize.min,
+                      children: [
+                        Text(
+                          'profile.last7Days'.tr(),
+                          style: TextStyle(
+                            color: Theme.of(
+                              context,
+                            ).colorScheme.onSurfaceVariant,
+                            fontSize: 12,
+                            fontWeight: FontWeight.w500,
+                          ),
+                        ),
+                        if (activities.isNotEmpty) ...[
+                          const SizedBox(width: 4),
+                          Icon(
+                            Icons.chevron_right,
+                            size: 16,
+                            color: Theme.of(
+                              context,
+                            ).colorScheme.onSurfaceVariant,
+                          ),
+                        ],
+                      ],
+                    ),
+                  ),
+                ],
+              ),
+            ),
+            GlassmorphicContainer(
+              child: isLoading && activities.isEmpty
+                  ? SizedBox(
+                      width: double.infinity,
+                      child: Padding(
+                        padding: const EdgeInsets.all(24.0),
+                        child: ShimmerContainer(
+                          child: Column(
+                            crossAxisAlignment: CrossAxisAlignment.start,
+                            children: [
+                              SizedBox(
+                                height: 120,
+                                child: Row(
+                                  mainAxisAlignment:
+                                      MainAxisAlignment.spaceBetween,
+                                  crossAxisAlignment: CrossAxisAlignment.end,
+                                  children: List.generate(
+                                    7,
+                                    (index) => Expanded(
+                                      child: Padding(
+                                        padding: const EdgeInsets.symmetric(
+                                          horizontal: 4,
+                                        ),
+                                        child: SkeletonBox(
+                                          height: 20.0 + (index % 3) * 30.0,
+                                          borderRadius: 4,
+                                        ),
+                                      ),
+                                    ),
+                                  ),
+                                ),
+                              ),
+                              const SizedBox(height: 6),
+                              Row(
+                                children: List.generate(
+                                  7,
+                                  (index) => const Expanded(
+                                    child: Center(
+                                      child: SkeletonBox(
+                                        width: 20,
+                                        height: 12,
+                                        borderRadius: 2,
+                                      ),
+                                    ),
+                                  ),
+                                ),
+                              ),
+                              const SizedBox(height: 16),
+                              Row(
+                                mainAxisAlignment:
+                                    MainAxisAlignment.spaceAround,
+                                children: List.generate(
+                                  3,
+                                  (index) => const Column(
+                                    children: [
+                                      SkeletonCircle(size: 20),
+                                      SizedBox(height: 4),
+                                      SkeletonBox(
+                                        width: 40,
+                                        height: 16,
+                                        borderRadius: 4,
+                                      ),
+                                      SizedBox(height: 4),
+                                      SkeletonBox(
+                                        width: 60,
+                                        height: 12,
+                                        borderRadius: 4,
+                                      ),
+                                    ],
+                                  ),
+                                ),
+                              ),
+                            ],
+                          ),
+                        ),
+                      ),
+                    )
+                  : activities.isEmpty
+                  ? Center(
+                      child: Padding(
+                        padding: const EdgeInsets.all(24.0),
+                        child: Text(
+                          activityError == null || activityError.isEmpty
+                              ? 'profile.noActivityDataYet'.tr()
+                              : activityError,
+                          style: const TextStyle(color: AppColors.grey600),
+                          textAlign: TextAlign.center,
+                        ),
+                      ),
+                    )
+                  : Column(
+                      children: [
+                        // XP Chart with animated bars
+                        SizedBox(
+                          height: 120,
+                          child: Row(
+                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                            crossAxisAlignment: CrossAxisAlignment.end,
+                            children: activities.asMap().entries.map((entry) {
+                              final index = entry.key;
+                              final activity = entry.value;
+                              final maxXP = activities
+                                  .map((a) => a.xpEarned)
+                                  .reduce((a, b) => a > b ? a : b);
+                              final normalizedValue = maxXP > 0
+                                  ? activity.xpEarned / maxXP
+                                  : 0.0;
+
+                              return Expanded(
+                                child: AnimatedActivityBar(
+                                  label: '',
+                                  value: normalizedValue,
+                                  xpValue: activity.xpEarned,
+                                  color: AppColorRoles.primary(isDark),
+                                  delay: Duration(milliseconds: index * 100),
+                                ),
+                              );
+                            }).toList(),
+                          ),
+                        ),
+                        // Day labels row — separate from bars to ensure alignment
+                        const SizedBox(height: 6),
+                        Row(
+                          children: activities.map((activity) {
+                            String dayLabel;
+                            final parsedDate = DateTime.tryParse(activity.date);
+                            if (parsedDate != null) {
+                              dayLabel = DateFormat(
+                                'E',
+                              ).format(parsedDate).substring(0, 1);
+                            } else {
+                              final raw = activity.date.trim();
+                              dayLabel = raw.isEmpty
+                                  ? '-'
+                                  : raw.substring(0, 1).toUpperCase();
+                            }
+                            return Expanded(
+                              child: Center(
+                                child: Text(
+                                  dayLabel,
+                                  style: TextStyle(
+                                    fontSize: 12,
+                                    fontWeight: FontWeight.w500,
+                                    color: isDark
+                                        ? AppColors.grey500
+                                        : AppColors.grey600,
+                                  ),
+                                ),
+                              ),
+                            );
+                          }).toList(),
+                        ),
+                        const SizedBox(height: 16),
+                        // Summary stats
+                        Row(
+                          mainAxisAlignment: MainAxisAlignment.spaceAround,
+                          children: [
+                            _ActivityStat(
+                              label: 'profile.totalXp'.tr(),
+                              value:
+                                  '${activities.fold<int>(0, (sum, a) => sum + a.xpEarned)}',
+                              icon: Icons.star,
+                              color: AppColors.warning,
+                            ),
+                            _ActivityStat(
+                              label: 'profile.lessons'.tr(),
+                              value:
+                                  '${activities.fold<int>(0, (sum, a) => sum + a.lessonsCompleted)}',
+                              icon: Icons.menu_book,
+                              color: AppColorRoles.primary(isDark),
+                            ),
+                            _ActivityStat(
+                              label: 'profile.words'.tr(),
+                              value:
+                                  '${activities.fold<int>(0, (sum, a) => sum + a.vocabularyLearned)}',
+                              icon: Icons.abc,
+                              color: AppColors.greenSuccessBright,
+                            ),
+                          ],
+                        ),
+                      ],
+                    ),
+            ),
+          ],
+        );
+      },
+    );
+  }
+}
+
+class _ActivityStat extends StatelessWidget {
+  final String label;
+  final String value;
+  final IconData icon;
+  final Color color;
+
+  const _ActivityStat({
+    required this.label,
+    required this.value,
+    required this.icon,
+    required this.color,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        Icon(icon, size: 20, color: color),
+        const SizedBox(height: 4),
+        Text(
+          value,
+          style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
+        ),
+        Text(
+          label,
+          style: const TextStyle(fontSize: 11, color: AppColors.grey600),
+        ),
+      ],
+    );
+  }
+}
+
+class _WeeklyActivityDetailSheet extends StatelessWidget {
+  final List<WeeklyActivityEntity> activities;
+
+  const _WeeklyActivityDetailSheet({required this.activities});
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final primary = AppColorRoles.primary(isDark);
+
+    final totalXP = activities.fold<int>(0, (s, a) => s + a.xpEarned);
+    final totalLessons = activities.fold<int>(
+      0,
+      (s, a) => s + a.lessonsCompleted,
+    );
+    final totalWords = activities.fold<int>(
+      0,
+      (s, a) => s + a.vocabularyLearned,
+    );
+    final maxXP = activities
+        .map((a) => a.xpEarned)
+        .reduce((a, b) => a > b ? a : b);
+    return DraggableScrollableSheet(
+      initialChildSize: 0.75,
+      minChildSize: 0.5,
+      maxChildSize: 0.95,
+      expand: false,
+      builder: (_, scrollController) {
+        return Container(
+          decoration: BoxDecoration(
+            color: isDark ? const Color(0xFF1A1A2E) : Colors.white,
+            borderRadius: const BorderRadius.vertical(top: Radius.circular(24)),
+            boxShadow: [
+              BoxShadow(
+                color: Colors.black.withValues(alpha: 0.2),
+                blurRadius: 20,
+                offset: const Offset(0, -4),
+              ),
+            ],
+          ),
+          child: Column(
+            children: [
+              // Drag handle
+              Container(
+                margin: const EdgeInsets.only(top: 12),
+                width: 40,
+                height: 4,
+                decoration: BoxDecoration(
+                  color: AppColors.grey400,
+                  borderRadius: BorderRadius.circular(2),
+                ),
+              ),
+              // Header
+              Padding(
+                padding: const EdgeInsets.fromLTRB(20, 20, 20, 8),
+                child: Row(
+                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                  children: [
+                    Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Text(
+                          'profile.weeklyActivity'.tr(),
+                          style: TextStyle(
+                            fontSize: 20,
+                            fontWeight: FontWeight.bold,
+                          ),
+                        ),
+                        Text(
+                          'profile.last7DaysDetailedBreakdown'.tr(),
+                          style: TextStyle(
+                            fontSize: 12,
+                            color: Theme.of(
+                              context,
+                            ).colorScheme.onSurfaceVariant,
+                          ),
+                        ),
+                      ],
+                    ),
+                    GestureDetector(
+                      onTap: () => Navigator.pop(context),
+                      child: Container(
+                        padding: const EdgeInsets.all(8),
+                        decoration: BoxDecoration(
+                          color: isDark
+                              ? Colors.white.withValues(alpha: 0.08)
+                              : Colors.black.withValues(alpha: 0.06),
+                          shape: BoxShape.circle,
+                        ),
+                        child: const Icon(Icons.close, size: 16),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+              // Summary row
+              Padding(
+                padding: const EdgeInsets.symmetric(
+                  horizontal: 20,
+                  vertical: 8,
+                ),
+                child: Row(
+                  children: [
+                    _SummaryChip(
+                      icon: Icons.star,
+                      color: AppColors.warning,
+                      label: 'profile.xpValue'.tr(
+                        namedArgs: {'xp': '$totalXP'},
+                      ),
+                      sublabel: 'profile.total'.tr(),
+                    ),
+                    const SizedBox(width: 8),
+                    _SummaryChip(
+                      icon: Icons.menu_book,
+                      color: primary,
+                      label: '$totalLessons',
+                      sublabel: 'profile.lessons'.tr(),
+                    ),
+                    const SizedBox(width: 8),
+                    _SummaryChip(
+                      icon: Icons.abc,
+                      color: AppColors.greenSuccessBright,
+                      label: '$totalWords',
+                      sublabel: 'profile.words'.tr(),
+                    ),
+                  ],
+                ),
+              ),
+              const Divider(height: 1),
+              // Day list
+              Expanded(
+                child: ListView.builder(
+                  controller: scrollController,
+                  padding: const EdgeInsets.symmetric(vertical: 8),
+                  itemCount: activities.length,
+                  itemBuilder: (context, index) {
+                    final a = activities[index];
+                    final isBest = a.xpEarned == maxXP && maxXP > 0;
+                    final barFraction = maxXP > 0 ? a.xpEarned / maxXP : 0.0;
+
+                    DateTime? parsedDate = DateTime.tryParse(a.date);
+                    final String dayName = parsedDate != null
+                        ? DateFormat('EEEE').format(parsedDate)
+                        : a.date;
+                    final String shortDate = parsedDate != null
+                        ? DateFormat('MMM d').format(parsedDate)
+                        : '';
+
+                    return Container(
+                      margin: const EdgeInsets.symmetric(
+                        horizontal: 16,
+                        vertical: 4,
+                      ),
+                      padding: const EdgeInsets.all(14),
+                      decoration: BoxDecoration(
+                        color: isBest
+                            ? primary.withValues(alpha: isDark ? 0.15 : 0.08)
+                            : (isDark
+                                  ? Colors.white.withValues(alpha: 0.04)
+                                  : Colors.black.withValues(alpha: 0.03)),
+                        borderRadius: BorderRadius.circular(14),
+                        border: Border.all(
+                          color: isBest
+                              ? primary.withValues(alpha: 0.4)
+                              : Colors.transparent,
+                          width: 1.5,
+                        ),
+                      ),
+                      child: Column(
+                        crossAxisAlignment: CrossAxisAlignment.start,
+                        children: [
+                          Row(
+                            children: [
+                              Expanded(
+                                child: Row(
+                                  children: [
+                                    Text(
+                                      dayName,
+                                      style: const TextStyle(
+                                        fontWeight: FontWeight.w600,
+                                        fontSize: 14,
+                                      ),
+                                    ),
+                                    if (shortDate.isNotEmpty) ...[
+                                      const SizedBox(width: 6),
+                                      Text(
+                                        shortDate,
+                                        style: TextStyle(
+                                          fontSize: 12,
+                                          color: Theme.of(
+                                            context,
+                                          ).colorScheme.onSurfaceVariant,
+                                        ),
+                                      ),
+                                    ],
+                                  ],
+                                ),
+                              ),
+                              if (isBest)
+                                Container(
+                                  padding: const EdgeInsets.symmetric(
+                                    horizontal: 8,
+                                    vertical: 2,
+                                  ),
+                                  decoration: BoxDecoration(
+                                    color: AppColors.warning.withValues(
+                                      alpha: 0.15,
+                                    ),
+                                    borderRadius: BorderRadius.circular(8),
+                                    border: Border.all(
+                                      color: AppColors.warning.withValues(
+                                        alpha: 0.5,
+                                      ),
+                                    ),
+                                  ),
+                                  child: Row(
+                                    mainAxisSize: MainAxisSize.min,
+                                    children: [
+                                      Icon(
+                                        Icons.emoji_events,
+                                        size: 12,
+                                        color: AppColors.warning,
+                                      ),
+                                      SizedBox(width: 3),
+                                      Text(
+                                        'profile.bestDay'.tr(),
+                                        style: TextStyle(
+                                          fontSize: 11,
+                                          color: AppColors.warning,
+                                          fontWeight: FontWeight.w600,
+                                        ),
+                                      ),
+                                    ],
+                                  ),
+                                ),
+                            ],
+                          ),
+                          const SizedBox(height: 10),
+                          // XP bar
+                          if (a.xpEarned > 0) ...[
+                            Row(
+                              children: [
+                                Expanded(
+                                  child: ClipRRect(
+                                    borderRadius: BorderRadius.circular(4),
+                                    child: LinearProgressIndicator(
+                                      value: barFraction,
+                                      backgroundColor: primary.withValues(
+                                        alpha: 0.12,
+                                      ),
+                                      valueColor: AlwaysStoppedAnimation<Color>(
+                                        primary,
+                                      ),
+                                      minHeight: 6,
+                                    ),
+                                  ),
+                                ),
+                                const SizedBox(width: 10),
+                                Text(
+                                  'profile.xpValue'.tr(
+                                    namedArgs: {'xp': '${a.xpEarned}'},
+                                  ),
+                                  style: TextStyle(
+                                    fontSize: 13,
+                                    fontWeight: FontWeight.bold,
+                                    color: primary,
+                                  ),
+                                ),
+                              ],
+                            ),
+                            const SizedBox(height: 10),
+                          ],
+                          // Stats chips
+                          Row(
+                            children: [
+                              if (a.xpEarned == 0)
+                                Text(
+                                  'profile.noActivity'.tr(),
+                                  style: TextStyle(
+                                    fontSize: 12,
+                                    color: Theme.of(
+                                      context,
+                                    ).colorScheme.onSurfaceVariant,
+                                  ),
+                                )
+                              else ...[
+                                _MiniStat(
+                                  icon: Icons.menu_book,
+                                  color: primary,
+                                  value: 'profile.lessonsCount'.tr(
+                                    namedArgs: {
+                                      'count': '${a.lessonsCompleted}',
+                                    },
+                                  ),
+                                ),
+                                const SizedBox(width: 12),
+                                _MiniStat(
+                                  icon: Icons.abc,
+                                  color: AppColors.greenSuccessBright,
+                                  value: 'profile.wordsCount'.tr(
+                                    namedArgs: {
+                                      'count': '${a.vocabularyLearned}',
+                                    },
+                                  ),
+                                ),
+                              ],
+                            ],
+                          ),
+                        ],
+                      ),
+                    );
+                  },
+                ),
+              ),
+              // Bottom safe area
+              SizedBox(height: MediaQuery.of(context).padding.bottom + 16),
+            ],
+          ),
+        );
+      },
+    );
+  }
+}
+
+class _SummaryChip extends StatelessWidget {
+  final IconData icon;
+  final Color color;
+  final String label;
+  final String sublabel;
+
+  const _SummaryChip({
+    required this.icon,
+    required this.color,
+    required this.label,
+    required this.sublabel,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    return Expanded(
+      child: Container(
+        padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 12),
+        decoration: BoxDecoration(
+          color: color.withValues(alpha: isDark ? 0.12 : 0.08),
+          borderRadius: BorderRadius.circular(12),
+          border: Border.all(color: color.withValues(alpha: 0.25)),
+        ),
+        child: Row(
+          children: [
+            Icon(icon, size: 16, color: color),
+            const SizedBox(width: 6),
+            Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  label,
+                  style: TextStyle(
+                    fontSize: 13,
+                    fontWeight: FontWeight.bold,
+                    color: color,
+                  ),
+                ),
+                Text(
+                  sublabel,
+                  style: TextStyle(
+                    fontSize: 10,
+                    color: Theme.of(context).colorScheme.onSurfaceVariant,
+                  ),
+                ),
+              ],
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _MiniStat extends StatelessWidget {
+  final IconData icon;
+  final Color color;
+  final String value;
+
+  const _MiniStat({
+    required this.icon,
+    required this.color,
+    required this.value,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Icon(icon, size: 14, color: color),
+        const SizedBox(width: 4),
+        Text(
+          value,
+          style: TextStyle(
+            fontSize: 12,
+            color: Theme.of(context).colorScheme.onSurfaceVariant,
+          ),
+        ),
+      ],
+    );
+  }
+}
diff --git a/flutter-app/lib/features/progress/presentation/widgets/daily_challenges_widget.dart b/flutter-app/lib/features/progress/presentation/widgets/daily_challenges_widget.dart
index bdc3abee..bfc52e19 100644
--- a/flutter-app/lib/features/progress/presentation/widgets/daily_challenges_widget.dart
+++ b/flutter-app/lib/features/progress/presentation/widgets/daily_challenges_widget.dart
@@ -5,6 +5,7 @@ import 'package:provider/provider.dart';
 import '../../domain/entities/daily_challenge_entity.dart';
 import '../providers/daily_challenges_provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/game_icon.dart';
 import 'package:lexilingo_app/features/level/presentation/providers/level_provider.dart';
 
 /// Daily Challenges Card for Home Screen
@@ -29,24 +30,35 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
+    final isDark = theme.brightness == Brightness.dark;
 
     return Consumer<DailyChallengesProvider>(
       builder: (context, provider, child) {
         if (provider.isLoading && provider.challenges.isEmpty) {
-          return Card(
-            child: Padding(
-              padding: const EdgeInsets.all(20),
-              child: Column(
-                children: [
-                  const LottieLoadingWidget.small(),
-                  const SizedBox(height: 12),
-                  Text(
-                    'home.loadingChallenges'.tr(),
-                    style: theme.textTheme.bodyMedium,
-                  ),
-                ],
+          return Container(
+            padding: const EdgeInsets.all(20),
+            decoration: BoxDecoration(
+              color: isDark ? AppColors.surfaceDarkMuted : AppColors.surfaceLight,
+              borderRadius: BorderRadius.circular(20),
+              border: Border.all(
+                color: isDark
+                    ? Colors.white.withValues(alpha: 0.08)
+                    : AppColors.grey200,
+                width: 2,
               ),
             ),
+            child: Column(
+              children: [
+                const LottieLoadingWidget.small(),
+                const SizedBox(height: 12),
+                Text(
+                  'home.loadingChallenges'.tr(),
+                  style: theme.textTheme.bodyMedium?.copyWith(
+                    color: AppColorRoles.textSecondary(isDark),
+                  ),
+                ),
+              ],
+            ),
           );
         }
 
@@ -54,12 +66,36 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
           return const SizedBox.shrink();
         }
 
-        return Card(
+        final accent = AppColors.purple;
+
+        return Material(
+          color: Colors.transparent,
           child: InkWell(
             onTap: () => _showChallengesSheet(context, provider),
-            borderRadius: BorderRadius.circular(12),
-            child: Padding(
-              padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
+            borderRadius: BorderRadius.circular(20),
+            child: Ink(
+              padding: const EdgeInsets.all(16),
+              decoration: BoxDecoration(
+                color: isDark
+                    ? AppColors.surfaceDarkMuted
+                    : AppColors.surfaceLight,
+                borderRadius: BorderRadius.circular(20),
+                border: Border.all(
+                  color: isDark
+                      ? accent.withValues(alpha: 0.35)
+                      : accent.withValues(alpha: 0.22),
+                  width: 2,
+                ),
+                boxShadow: [
+                  BoxShadow(
+                    color: isDark
+                        ? Colors.black.withValues(alpha: 0.3)
+                        : accent.withValues(alpha: 0.12),
+                    blurRadius: 0,
+                    offset: const Offset(0, 4),
+                  ),
+                ],
+              ),
               child: Column(
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
@@ -67,18 +103,20 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
                   Row(
                     children: [
                       Container(
-                        padding: const EdgeInsets.all(6),
+                        width: 40,
+                        height: 40,
+                        padding: const EdgeInsets.all(8),
                         decoration: BoxDecoration(
-                          color: Colors.purple.shade100,
-                          borderRadius: BorderRadius.circular(6),
+                          color: accent.withValues(alpha: isDark ? 0.22 : 0.14),
+                          borderRadius: BorderRadius.circular(12),
                         ),
-                        child: Icon(
-                          Icons.star,
-                          color: Colors.purple.shade700,
-                          size: 16,
+                        child: const AppGameIcon(
+                          GameIcon.star,
+                          size: 22,
+                          fallbackColor: AppColors.purple,
                         ),
                       ),
-                      const SizedBox(width: 10),
+                      const SizedBox(width: 12),
                       Expanded(
                         child: Column(
                           crossAxisAlignment: CrossAxisAlignment.start,
@@ -87,7 +125,7 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
                               'home.dailyChallenges'.tr(),
                               style: theme.textTheme.titleMedium?.copyWith(
                                 fontWeight: FontWeight.bold,
-                                fontSize: 15,
+                                color: AppColorRoles.textPrimary(isDark),
                               ),
                             ),
                             Text(
@@ -98,8 +136,7 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
                                 },
                               ),
                               style: theme.textTheme.bodySmall?.copyWith(
-                                color: Colors.grey,
-                                fontSize: 11,
+                                color: AppColorRoles.textSecondary(isDark),
                               ),
                             ),
                           ],
@@ -108,28 +145,36 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
                       // XP earned
                       Container(
                         padding: const EdgeInsets.symmetric(
-                          horizontal: 6,
-                          vertical: 3,
+                          horizontal: 8,
+                          vertical: 4,
                         ),
                         decoration: BoxDecoration(
-                          color: Colors.amber.shade100,
-                          borderRadius: BorderRadius.circular(10),
+                          color: AppColors.warning.withValues(
+                            alpha: isDark ? 0.22 : 0.16,
+                          ),
+                          borderRadius: BorderRadius.circular(12),
+                          border: Border.all(
+                            color: AppColors.warning.withValues(alpha: 0.4),
+                            width: 1.5,
+                          ),
                         ),
                         child: Row(
                           mainAxisSize: MainAxisSize.min,
                           children: [
-                            Icon(
-                              Icons.star,
-                              size: 10,
-                              color: Colors.amber.shade800,
+                            const AppGameIcon(
+                              GameIcon.star,
+                              size: 13,
+                              fallbackColor: AppColors.warningDark,
                             ),
-                            const SizedBox(width: 3),
+                            const SizedBox(width: 4),
                             Text(
                               '+${provider.xpEarned} XP',
                               style: TextStyle(
-                                fontSize: 11,
+                                fontSize: 12,
                                 fontWeight: FontWeight.bold,
-                                color: Colors.amber.shade800,
+                                color: isDark
+                                    ? AppColors.warning
+                                    : AppColors.warningDark,
                               ),
                             ),
                           ],
@@ -137,28 +182,30 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
                       ),
                     ],
                   ),
-                  const SizedBox(height: 10),
+                  const SizedBox(height: 16),
 
                   // Progress bar
                   ClipRRect(
-                    borderRadius: BorderRadius.circular(3),
+                    borderRadius: BorderRadius.circular(4),
                     child: LinearProgressIndicator(
                       value: provider.progress,
-                      backgroundColor: AppColors.grey200,
+                      backgroundColor: isDark
+                          ? Colors.white.withValues(alpha: 0.1)
+                          : AppColors.grey200,
                       valueColor: AlwaysStoppedAnimation<Color>(
                         provider.allCompleted
                             ? AppColors.greenSuccessBright
                             : AppColors.purple,
                       ),
-                      minHeight: 5,
+                      minHeight: 8,
                     ),
                   ),
-                  const SizedBox(height: 10),
+                  const SizedBox(height: 16),
 
                   // Mini challenge list
                   ...provider.challenges.take(3).map((challenge) {
                     return Padding(
-                      padding: const EdgeInsets.only(bottom: 6),
+                      padding: const EdgeInsets.only(bottom: 8),
                       child: _buildMiniChallenge(context, challenge, provider),
                     );
                   }),
@@ -166,25 +213,23 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
                   // View all button
                   if (provider.challenges.length > 3)
                     Center(
-                      child: Padding(
-                        padding: const EdgeInsets.only(top: 2),
-                        child: InkWell(
-                          onTap: () => _showChallengesSheet(context, provider),
-                          borderRadius: BorderRadius.circular(4),
-                          child: Padding(
-                            padding: const EdgeInsets.symmetric(vertical: 4, horizontal: 8),
-                            child: Text(
-                              'home.viewAllChallenges'.tr(
-                                namedArgs: {
-                                  'count': '${provider.challenges.length}',
-                                },
-                              ),
-                              style: TextStyle(
-                                color: Colors.purple.shade600,
-                                fontSize: 12,
-                                fontWeight: FontWeight.bold,
-                              ),
-                            ),
+                      child: TextButton(
+                        onPressed: () =>
+                            _showChallengesSheet(context, provider),
+                        style: TextButton.styleFrom(
+                          minimumSize: const Size(44, 44),
+                        ),
+                        child: Text(
+                          'home.viewAllChallenges'.tr(
+                            namedArgs: {
+                              'count': '${provider.challenges.length}',
+                            },
+                          ),
+                          style: TextStyle(
+                            color: isDark
+                                ? AppColors.purpleLight
+                                : AppColors.purple,
+                            fontWeight: FontWeight.w600,
                           ),
                         ),
                       ),
@@ -204,14 +249,16 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
     DailyChallengesProvider provider,
   ) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
+    final categoryColor = _getCategoryColor(challenge.category, isDark: isDark);
+    final textMuted = AppColorRoles.textSecondary(isDark);
     return Row(
       children: [
-        Icon(
+        AppGameIcon(
           _getCategoryIcon(challenge.category),
-          size: 14,
-          color: _getCategoryColor(challenge.category, isDark: isDark),
+          size: 18,
+          fallbackColor: categoryColor,
         ),
-        const SizedBox(width: 6),
+        const SizedBox(width: 8),
         Expanded(
           child: Text(
             challenge.title,
@@ -219,19 +266,24 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
               decoration: challenge.isCompleted
                   ? TextDecoration.lineThrough
                   : null,
-              color: challenge.isCompleted ? Colors.grey : null,
-              fontSize: 13,
+              color: challenge.isCompleted
+                  ? textMuted
+                  : AppColorRoles.textPrimary(isDark),
             ),
           ),
         ),
         if (challenge.isCompleted)
-          Icon(Icons.check_circle, color: Colors.green.shade400, size: 16)
+          AppGameIcon(
+            GameIcon.checkmark,
+            size: 20,
+            fallbackColor: AppColors.greenSuccessBright,
+          )
         else
           Text(
             '${challenge.current}/${challenge.target}',
-            style: Theme.of(
-              context,
-            ).textTheme.bodySmall?.copyWith(color: Colors.grey, fontSize: 11),
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: textMuted,
+            ),
           ),
       ],
     );
@@ -256,34 +308,34 @@ class _DailyChallengesCardState extends State<DailyChallengesCard> {
       case 'vocabulary':
         return AppColors.purple;
       case 'streak':
-        return AppColors.orange;
+        return AppColors.deepOrange;
       case 'xp':
-        return AppColors.warning;
+        return isDark ? AppColors.warning : AppColors.warningDark;
       case 'voice':
         return Colors.pink;
       case 'social':
         return AppColors.teal;
       default:
-        return Colors.grey;
+        return AppColors.grey500;
     }
   }
 
-  IconData _getCategoryIcon(String category) {
+  GameIcon _getCategoryIcon(String category) {
     switch (category) {
       case 'lesson':
-        return Icons.school_rounded;
+        return GameIcon.lessonBoard;
       case 'vocabulary':
-        return Icons.library_books_rounded;
+        return GameIcon.book;
       case 'streak':
-        return Icons.local_fire_department_rounded;
+        return GameIcon.streakFire;
       case 'xp':
-        return Icons.bolt_rounded;
+        return GameIcon.bolt;
       case 'voice':
-        return Icons.mic_rounded;
+        return GameIcon.microphone;
       case 'social':
-        return Icons.people_rounded;
+        return GameIcon.peoplePair;
       default:
-        return Icons.star_rounded;
+        return GameIcon.star;
     }
   }
 }
@@ -297,11 +349,13 @@ class DailyChallengesSheet extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
+    final isDark = theme.brightness == Brightness.dark;
+    final accent = AppColors.purple;
 
     return Container(
       decoration: BoxDecoration(
-        color: theme.scaffoldBackgroundColor,
-        borderRadius: const BorderRadius.vertical(top: Radius.circular(20)),
+        color: isDark ? AppColors.surfaceDark : theme.scaffoldBackgroundColor,
+        borderRadius: const BorderRadius.vertical(top: Radius.circular(24)),
       ),
       padding: const EdgeInsets.all(24),
       child: Column(
@@ -314,7 +368,7 @@ class DailyChallengesSheet extends StatelessWidget {
               width: 40,
               height: 4,
               decoration: BoxDecoration(
-                color: AppColors.grey300,
+                color: isDark ? Colors.white.withValues(alpha: 0.2) : AppColors.grey300,
                 borderRadius: BorderRadius.circular(2),
               ),
             ),
@@ -324,7 +378,11 @@ class DailyChallengesSheet extends StatelessWidget {
           // Header
           Row(
             children: [
-              Icon(Icons.star, size: 28, color: AppColors.purple),
+              AppGameIcon(
+                GameIcon.star,
+                size: 28,
+                fallbackColor: isDark ? AppColors.purpleLight : accent,
+              ),
               const SizedBox(width: 12),
               Expanded(
                 child: Column(
@@ -334,15 +392,16 @@ class DailyChallengesSheet extends StatelessWidget {
                       'home.dailyChallenges'.tr(),
                       style: theme.textTheme.headlineSmall?.copyWith(
                         fontWeight: FontWeight.bold,
+                        color: AppColorRoles.textPrimary(isDark),
                       ),
                     ),
                     Text(
                       'home.completeBonusXp'.tr(
                         namedArgs: {'xp': '${provider.bonusXp}'},
                       ),
-
                       style: theme.textTheme.bodySmall?.copyWith(
-                        color: AppColors.purple,
+                        color: isDark ? AppColors.purpleLight : accent,
+                        fontWeight: FontWeight.w600,
                       ),
                     ),
                   ],
@@ -360,11 +419,13 @@ class DailyChallengesSheet extends StatelessWidget {
                   borderRadius: BorderRadius.circular(6),
                   child: LinearProgressIndicator(
                     value: provider.progress,
-                    backgroundColor: AppColors.grey200,
+                    backgroundColor: isDark
+                        ? Colors.white.withValues(alpha: 0.1)
+                        : AppColors.grey200,
                     valueColor: AlwaysStoppedAnimation<Color>(
                       provider.allCompleted
                           ? AppColors.greenSuccessBright
-                          : AppColors.purple,
+                          : accent,
                     ),
                     minHeight: 12,
                   ),
@@ -375,6 +436,7 @@ class DailyChallengesSheet extends StatelessWidget {
                 '${provider.completedCount}/${provider.totalChallenges}',
                 style: theme.textTheme.titleMedium?.copyWith(
                   fontWeight: FontWeight.bold,
+                  color: AppColorRoles.textPrimary(isDark),
                 ),
               ),
             ],
@@ -386,7 +448,7 @@ class DailyChallengesSheet extends StatelessWidget {
             child: ListView.separated(
               shrinkWrap: true,
               itemCount: provider.challenges.length,
-              separatorBuilder: (_, __) => const SizedBox(height: 12),
+              separatorBuilder: (_, _) => const SizedBox(height: 12),
               itemBuilder: (context, index) {
                 final challenge = provider.challenges[index];
                 return _ChallengeCard(
@@ -405,16 +467,29 @@ class DailyChallengesSheet extends StatelessWidget {
               padding: const EdgeInsets.all(16),
               decoration: BoxDecoration(
                 gradient: LinearGradient(
-                  colors: [Colors.amber.shade200, Colors.orange.shade200],
+                  colors: isDark
+                      ? [
+                          AppColors.warning.withValues(alpha: 0.3),
+                          AppColors.orange.withValues(alpha: 0.3),
+                        ]
+                      : AppColors.warmGradient
+                          .map((c) => c.withValues(alpha: 0.22))
+                          .toList(),
+                ),
+                borderRadius: BorderRadius.circular(16),
+                border: Border.all(
+                  color: AppColors.orange.withValues(alpha: 0.35),
+                  width: 2,
                 ),
-                borderRadius: BorderRadius.circular(12),
               ),
               child: Row(
                 children: [
-                  Icon(
-                    Icons.emoji_events,
-                    size: 32,
-                    color: Colors.amber.shade800,
+                  AppGameIcon(
+                    GameIcon.trophy,
+                    size: 36,
+                    fallbackColor: isDark
+                        ? AppColors.warning
+                        : AppColors.warningDark,
                   ),
                   const SizedBox(width: 12),
                   Expanded(
@@ -425,25 +500,27 @@ class DailyChallengesSheet extends StatelessWidget {
                           'home.allChallengesComplete'.tr(),
                           style: theme.textTheme.titleMedium?.copyWith(
                             fontWeight: FontWeight.bold,
+                            color: AppColorRoles.textPrimary(isDark),
                           ),
                         ),
                         Text(
                           'home.bonusXpEarned'.tr(
                             namedArgs: {'xp': '${provider.bonusXp}'},
                           ),
-
                           style: TextStyle(
-                            color: Colors.orange.shade800,
+                            color: isDark
+                                ? AppColors.warning
+                                : AppColors.deepOrange,
                             fontWeight: FontWeight.w600,
                           ),
                         ),
                       ],
                     ),
                   ),
-                  const Icon(
-                    Icons.check_circle,
-                    color: AppColors.greenSuccessBright,
+                  const AppGameIcon(
+                    GameIcon.checkmark,
                     size: 32,
+                    fallbackColor: AppColors.greenSuccessBright,
                   ),
                 ],
               ),
@@ -491,37 +568,56 @@ class _ChallengeCard extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
-    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final isDark = theme.brightness == Brightness.dark;
+    final categoryColor = _getCategoryColor(challenge.category, isDark: isDark);
+    final textMuted = AppColorRoles.textSecondary(isDark);
+
+    final completedBg = isDark
+        ? AppColors.greenSuccessBright.withValues(alpha: 0.12)
+        : AppColors.greenSuccessBg;
+    final completedBorder = isDark
+        ? AppColors.greenSuccessBright.withValues(alpha: 0.4)
+        : AppColors.greenSuccessSoft.withValues(alpha: 0.6);
+    final defaultBg = isDark ? AppColors.surfaceDarkMuted : AppColors.surfaceLight;
+    final defaultBorder = isDark
+        ? Colors.white.withValues(alpha: 0.1)
+        : AppColors.grey200;
 
     return Container(
       padding: const EdgeInsets.all(16),
       decoration: BoxDecoration(
-        color: challenge.isCompleted ? Colors.green.shade50 : theme.cardColor,
-        borderRadius: BorderRadius.circular(12),
+        color: challenge.isCompleted ? completedBg : defaultBg,
+        borderRadius: BorderRadius.circular(16),
         border: Border.all(
-          color: challenge.isCompleted
-              ? Colors.green.shade200
-              : AppColors.grey200,
+          color: challenge.isCompleted ? completedBorder : defaultBorder,
+          width: 2,
         ),
+        boxShadow: [
+          BoxShadow(
+            color: isDark
+                ? Colors.black.withValues(alpha: 0.25)
+                : Colors.black.withValues(alpha: 0.04),
+            blurRadius: 0,
+            offset: const Offset(0, 3),
+          ),
+        ],
       ),
       child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           // Icon
           Container(
             width: 48,
             height: 48,
             decoration: BoxDecoration(
-              color: _getCategoryColor(
-                challenge.category,
-                isDark: isDark,
-              ).withValues(alpha: 0.2),
-              borderRadius: BorderRadius.circular(12),
+              color: categoryColor.withValues(alpha: isDark ? 0.25 : 0.16),
+              borderRadius: BorderRadius.circular(14),
             ),
             child: Center(
-              child: Icon(
+              child: AppGameIcon(
                 _getCategoryIcon(challenge.category),
-                size: 24,
-                color: _getCategoryColor(challenge.category, isDark: isDark),
+                size: 26,
+                fallbackColor: categoryColor,
               ),
             ),
           ),
@@ -536,6 +632,7 @@ class _ChallengeCard extends StatelessWidget {
                   challenge.title,
                   style: theme.textTheme.titleSmall?.copyWith(
                     fontWeight: FontWeight.bold,
+                    color: AppColorRoles.textPrimary(isDark),
                     decoration: challenge.isCompleted
                         ? TextDecoration.lineThrough
                         : null,
@@ -545,7 +642,7 @@ class _ChallengeCard extends StatelessWidget {
                 Text(
                   challenge.description,
                   style: theme.textTheme.bodySmall?.copyWith(
-                    color: Colors.grey,
+                    color: textMuted,
                   ),
                 ),
                 const SizedBox(height: 8),
@@ -557,14 +654,13 @@ class _ChallengeCard extends StatelessWidget {
                         borderRadius: BorderRadius.circular(4),
                         child: LinearProgressIndicator(
                           value: challenge.progress,
-                          backgroundColor: AppColors.grey200,
+                          backgroundColor: isDark
+                              ? Colors.white.withValues(alpha: 0.1)
+                              : AppColors.grey200,
                           valueColor: AlwaysStoppedAnimation<Color>(
                             challenge.isCompleted
                                 ? AppColors.greenSuccessBright
-                                : _getCategoryColor(
-                                    challenge.category,
-                                    isDark: isDark,
-                                  ),
+                                : categoryColor,
                           ),
                           minHeight: 6,
                         ),
@@ -573,7 +669,9 @@ class _ChallengeCard extends StatelessWidget {
                     const SizedBox(width: 8),
                     Text(
                       '${challenge.current}/${challenge.target}',
-                      style: theme.textTheme.bodySmall,
+                      style: theme.textTheme.bodySmall?.copyWith(
+                        color: textMuted,
+                      ),
                     ),
                   ],
                 ),
@@ -588,20 +686,34 @@ class _ChallengeCard extends StatelessWidget {
               Container(
                 padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                 decoration: BoxDecoration(
-                  color: Colors.amber.shade100,
+                  color: AppColors.warning.withValues(
+                    alpha: isDark ? 0.22 : 0.16,
+                  ),
                   borderRadius: BorderRadius.circular(8),
+                  border: Border.all(
+                    color: AppColors.warning.withValues(alpha: 0.4),
+                    width: 1.5,
+                  ),
                 ),
                 child: Row(
                   mainAxisSize: MainAxisSize.min,
                   children: [
-                    Icon(Icons.star, size: 12, color: Colors.amber.shade800),
+                    AppGameIcon(
+                      GameIcon.star,
+                      size: 12,
+                      fallbackColor: isDark
+                          ? AppColors.warning
+                          : AppColors.warningDark,
+                    ),
                     const SizedBox(width: 2),
                     Text(
                       '${challenge.xpReward}',
                       style: TextStyle(
                         fontSize: 12,
                         fontWeight: FontWeight.bold,
-                        color: Colors.amber.shade800,
+                        color: isDark
+                            ? AppColors.warning
+                            : AppColors.warningDark,
                       ),
                     ),
                   ],
@@ -610,20 +722,27 @@ class _ChallengeCard extends StatelessWidget {
               const SizedBox(height: 8),
               if (challenge.isCompleted)
                 if (isClaimed)
-                  const Icon(
-                    Icons.check_circle,
-                    color: AppColors.greenSuccessBright,
+                  const AppGameIcon(
+                    GameIcon.checkmark,
                     size: 28,
+                    fallbackColor: AppColors.greenSuccessBright,
                   )
                 else
-                  SizedBox(
-                    height: 28,
+                  ConstrainedBox(
+                    constraints: const BoxConstraints(minHeight: 44, minWidth: 44),
                     child: ElevatedButton(
                       onPressed: onClaim,
                       style: ElevatedButton.styleFrom(
                         backgroundColor: AppColors.greenSuccessBright,
-                        padding: const EdgeInsets.symmetric(horizontal: 8),
-                        textStyle: const TextStyle(fontSize: 11),
+                        foregroundColor: Colors.white,
+                        padding: const EdgeInsets.symmetric(horizontal: 12),
+                        textStyle: const TextStyle(
+                          fontSize: 11,
+                          fontWeight: FontWeight.w700,
+                        ),
+                        shape: RoundedRectangleBorder(
+                          borderRadius: BorderRadius.circular(10),
+                        ),
                       ),
                       child: Text('home.claimReward'.tr()),
                     ),
@@ -642,34 +761,34 @@ class _ChallengeCard extends StatelessWidget {
       case 'vocabulary':
         return AppColors.purple;
       case 'streak':
-        return AppColors.orange;
+        return AppColors.deepOrange;
       case 'xp':
-        return AppColors.warning;
+        return isDark ? AppColors.warning : AppColors.warningDark;
       case 'voice':
         return Colors.pink;
       case 'social':
         return AppColors.teal;
       default:
-        return Colors.grey;
+        return AppColors.grey500;
     }
   }
 
-  IconData _getCategoryIcon(String category) {
+  GameIcon _getCategoryIcon(String category) {
     switch (category) {
       case 'lesson':
-        return Icons.school_rounded;
+        return GameIcon.lessonBoard;
       case 'vocabulary':
-        return Icons.library_books_rounded;
+        return GameIcon.book;
       case 'streak':
-        return Icons.local_fire_department_rounded;
+        return GameIcon.streakFire;
       case 'xp':
-        return Icons.bolt_rounded;
+        return GameIcon.bolt;
       case 'voice':
-        return Icons.mic_rounded;
+        return GameIcon.microphone;
       case 'social':
-        return Icons.people_rounded;
+        return GameIcon.peoplePair;
       default:
-        return Icons.star_rounded;
+        return GameIcon.star;
     }
   }
 }
diff --git a/flutter-app/lib/features/user/presentation/pages/settings_page.dart b/flutter-app/lib/features/user/presentation/pages/settings_page.dart
index e1a1f981..598ba59f 100644
--- a/flutter-app/lib/features/user/presentation/pages/settings_page.dart
+++ b/flutter-app/lib/features/user/presentation/pages/settings_page.dart
@@ -189,6 +189,20 @@ class _SettingsPageState extends State<SettingsPage> {
                   index: 5,
                   duration: const Duration(milliseconds: 300),
                   delayPerItem: const Duration(milliseconds: 50),
+                  child: _buildSectionHeader(
+                    context,
+                    icon: Icons.cloud_sync_outlined,
+                    title: 'offlineSync.settingsTitle'.tr(),
+                    subtitle: 'offlineSync.settingsSubtitle'.tr(),
+                  ),
+                ),
+                const SizedBox(height: 12),
+                _buildOfflineSyncSection(context),
+                const SizedBox(height: 32),
+                AnimatedListItem(
+                  index: 6,
+                  duration: const Duration(milliseconds: 300),
+                  delayPerItem: const Duration(milliseconds: 50),
                   child: _buildSectionHeader(
                     context,
                     icon: Icons.people_outline_rounded,
@@ -200,7 +214,7 @@ class _SettingsPageState extends State<SettingsPage> {
                 _buildReferralSection(context),
                 const SizedBox(height: 32),
                 AnimatedListItem(
-                  index: 6,
+                  index: 7,
                   duration: const Duration(milliseconds: 300),
                   delayPerItem: const Duration(milliseconds: 50),
                   child: _buildSectionHeader(
@@ -797,6 +811,72 @@ class _SettingsPageState extends State<SettingsPage> {
     );
   }
 
+  Widget _buildOfflineSyncSection(BuildContext context) {
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final primaryColor = AppColorRoles.primary(isDark);
+
+    return Container(
+      decoration: BoxDecoration(
+        color: Theme.of(context).cardColor,
+        borderRadius: BorderRadius.circular(16),
+        boxShadow: [
+          BoxShadow(
+            color: Theme.of(context).colorScheme.shadow.withValues(alpha: 0.05),
+            blurRadius: 10,
+            offset: const Offset(0, 2),
+          ),
+        ],
+      ),
+      child: InkWell(
+        onTap: () => Navigator.pushNamed(context, '/offline-sync'),
+        borderRadius: BorderRadius.circular(16),
+        child: Padding(
+          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
+          child: Row(
+            children: [
+              Container(
+                padding: const EdgeInsets.all(8),
+                decoration: BoxDecoration(
+                  color: primaryColor.withValues(alpha: 0.1),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: Icon(
+                  Icons.cloud_done_outlined,
+                  color: primaryColor,
+                  size: 20,
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      'offlineSync.title'.tr(),
+                      style: const TextStyle(
+                        fontSize: 15,
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    const SizedBox(height: 2),
+                    Text(
+                      'offlineSync.entrySubtitle'.tr(),
+                      style: TextStyle(
+                        fontSize: 13,
+                        color: AppColorRoles.textMuted(isDark),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+              Icon(Icons.chevron_right, color: AppColors.grey400, size: 20),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
   Widget _buildReferralSection(BuildContext context) {
     final isDark = Theme.of(context).brightness == Brightness.dark;
     return Container(
@@ -804,7 +884,9 @@ class _SettingsPageState extends State<SettingsPage> {
         color: Theme.of(context).cardColor,
         borderRadius: BorderRadius.circular(16),
         border: Border.all(
-          color: isDark ? Colors.white.withValues(alpha: 0.08) : Colors.black.withValues(alpha: 0.06),
+          color: isDark
+              ? Colors.white.withValues(alpha: 0.08)
+              : Colors.black.withValues(alpha: 0.06),
         ),
       ),
       child: ListTile(
@@ -816,12 +898,20 @@ class _SettingsPageState extends State<SettingsPage> {
             color: Colors.green.withValues(alpha: 0.1),
             borderRadius: BorderRadius.circular(10),
           ),
-          child: const Icon(Icons.card_giftcard_rounded, color: Colors.green, size: 20),
+          child: const Icon(
+            Icons.card_giftcard_rounded,
+            color: Colors.green,
+            size: 20,
+          ),
+        ),
+        title: Text(
+          'settings.invite_friends'.tr(),
+          style: const TextStyle(fontWeight: FontWeight.w600),
+        ),
+        subtitle: Text(
+          'settings.invite_friends_subtitle'.tr(),
+          style: const TextStyle(fontSize: 12),
         ),
-        title: Text('settings.invite_friends'.tr(),
-            style: const TextStyle(fontWeight: FontWeight.w600)),
-        subtitle: Text('settings.invite_friends_subtitle'.tr(),
-            style: const TextStyle(fontSize: 12)),
         trailing: const Icon(Icons.chevron_right, size: 20),
         onTap: () => _showReferralSheet(context),
       ),
@@ -845,21 +935,35 @@ class _SettingsPageState extends State<SettingsPage> {
             mainAxisSize: MainAxisSize.min,
             children: [
               Container(
-                width: 40, height: 4,
+                width: 40,
+                height: 4,
                 margin: const EdgeInsets.only(bottom: 20),
                 decoration: BoxDecoration(
-                  color: Colors.grey[300], borderRadius: BorderRadius.circular(2),
+                  color: Colors.grey[300],
+                  borderRadius: BorderRadius.circular(2),
                 ),
               ),
-              const Icon(Icons.card_giftcard_rounded, size: 48, color: Colors.green),
+              const Icon(
+                Icons.card_giftcard_rounded,
+                size: 48,
+                color: Colors.green,
+              ),
               const SizedBox(height: 12),
-              Text('settings.invite_title'.tr(),
-                  style: Theme.of(ctx).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold),
-                  textAlign: TextAlign.center),
+              Text(
+                'settings.invite_title'.tr(),
+                style: Theme.of(ctx).textTheme.headlineSmall?.copyWith(
+                  fontWeight: FontWeight.bold,
+                ),
+                textAlign: TextAlign.center,
+              ),
               const SizedBox(height: 8),
-              Text('settings.invite_desc'.tr(),
-                  style: Theme.of(ctx).textTheme.bodyMedium?.copyWith(color: Colors.grey),
-                  textAlign: TextAlign.center),
+              Text(
+                'settings.invite_desc'.tr(),
+                style: Theme.of(
+                  ctx,
+                ).textTheme.bodyMedium?.copyWith(color: Colors.grey),
+                textAlign: TextAlign.center,
+              ),
               const SizedBox(height: 24),
               FutureBuilder<Map<String, dynamic>>(
                 future: settingsProvider.getReferralCode(),
@@ -868,31 +972,48 @@ class _SettingsPageState extends State<SettingsPage> {
                     return const CircularProgressIndicator();
                   }
                   code = snap.data!['referral_code'] as String? ?? '';
-                  final total = (snap.data!['total_referrals'] as num?)?.toInt() ?? 0;
+                  final total =
+                      (snap.data!['total_referrals'] as num?)?.toInt() ?? 0;
                   return Column(
                     children: [
                       Container(
-                        padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 14),
+                        padding: const EdgeInsets.symmetric(
+                          horizontal: 20,
+                          vertical: 14,
+                        ),
                         decoration: BoxDecoration(
                           color: Colors.green.withValues(alpha: 0.08),
                           borderRadius: BorderRadius.circular(12),
-                          border: Border.all(color: Colors.green.withValues(alpha: 0.3)),
+                          border: Border.all(
+                            color: Colors.green.withValues(alpha: 0.3),
+                          ),
                         ),
                         child: Row(
                           mainAxisAlignment: MainAxisAlignment.center,
                           children: [
-                            Text(code ?? '',
-                                style: const TextStyle(
-                                  fontSize: 28, fontWeight: FontWeight.bold,
-                                  letterSpacing: 4, color: Colors.green,
-                                )),
+                            Text(
+                              code ?? '',
+                              style: const TextStyle(
+                                fontSize: 28,
+                                fontWeight: FontWeight.bold,
+                                letterSpacing: 4,
+                                color: Colors.green,
+                              ),
+                            ),
                             const SizedBox(width: 12),
                             IconButton(
-                              icon: const Icon(Icons.copy_rounded, color: Colors.green),
+                              icon: const Icon(
+                                Icons.copy_rounded,
+                                color: Colors.green,
+                              ),
                               onPressed: () {
-                                Clipboard.setData(ClipboardData(text: code ?? ''));
+                                Clipboard.setData(
+                                  ClipboardData(text: code ?? ''),
+                                );
                                 ScaffoldMessenger.of(ctx).showSnackBar(
-                                  SnackBar(content: Text('settings.code_copied'.tr())),
+                                  SnackBar(
+                                    content: Text('settings.code_copied'.tr()),
+                                  ),
                                 );
                               },
                             ),
@@ -901,8 +1022,13 @@ class _SettingsPageState extends State<SettingsPage> {
                       ),
                       const SizedBox(height: 8),
                       Text(
-                        'settings.referral_count'.tr(namedArgs: {'count': total.toString()}),
-                        style: const TextStyle(color: Colors.grey, fontSize: 13),
+                        'settings.referral_count'.tr(
+                          namedArgs: {'count': total.toString()},
+                        ),
+                        style: const TextStyle(
+                          color: Colors.grey,
+                          fontSize: 13,
+                        ),
                       ),
                       const SizedBox(height: 20),
                       FilledButton.icon(
@@ -955,7 +1081,8 @@ class _SettingsPageState extends State<SettingsPage> {
             onTap: () => Navigator.push(
               context,
               MaterialPageRoute(
-                builder: (_) => const LegalPage(type: LegalPageType.privacyPolicy),
+                builder: (_) =>
+                    const LegalPage(type: LegalPageType.privacyPolicy),
               ),
             ),
           ),
@@ -969,7 +1096,8 @@ class _SettingsPageState extends State<SettingsPage> {
             onTap: () => Navigator.push(
               context,
               MaterialPageRoute(
-                builder: (_) => const LegalPage(type: LegalPageType.termsOfService),
+                builder: (_) =>
+                    const LegalPage(type: LegalPageType.termsOfService),
               ),
             ),
           ),
@@ -979,13 +1107,18 @@ class _SettingsPageState extends State<SettingsPage> {
             builder: (context, snapshot) {
               final version = snapshot.data?.version ?? '—';
               return Padding(
-                padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
+                padding: const EdgeInsets.symmetric(
+                  horizontal: 16,
+                  vertical: 14,
+                ),
                 child: Row(
                   children: [
                     Container(
                       padding: const EdgeInsets.all(8),
                       decoration: BoxDecoration(
-                        color: AppColorRoles.primary(isDark).withValues(alpha: 0.1),
+                        color: AppColorRoles.primary(
+                          isDark,
+                        ).withValues(alpha: 0.1),
                         borderRadius: BorderRadius.circular(8),
                       ),
                       child: Icon(
diff --git a/flutter-app/lib/features/vocabulary/data/datasources/vocabulary_remote_datasource.dart b/flutter-app/lib/features/vocabulary/data/datasources/vocabulary_remote_datasource.dart
index 3a38db1f..23cbd8e9 100644
--- a/flutter-app/lib/features/vocabulary/data/datasources/vocabulary_remote_datasource.dart
+++ b/flutter-app/lib/features/vocabulary/data/datasources/vocabulary_remote_datasource.dart
@@ -69,6 +69,15 @@ class VocabularyRemoteDataSourceImpl implements VocabularyRemoteDataSource {
 
   VocabularyRemoteDataSourceImpl({required this.apiClient});
 
+  static List<dynamic> _readList(
+    Map<String, dynamic> response, {
+    String field = 'data',
+  }) {
+    final payload = response[field];
+    if (payload is List<dynamic>) return payload;
+    throw ServerException('Invalid list response');
+  }
+
   @override
   Future<List<VocabularyItemModel>> getVocabularyItems({
     String? courseId,
@@ -80,24 +89,20 @@ class VocabularyRemoteDataSourceImpl implements VocabularyRemoteDataSource {
     int offset = 0,
   }) async {
     try {
-      final pathParams = <String>[];
-      pathParams.add('limit=$limit');
-      pathParams.add('offset=$offset');
-      if (courseId != null) pathParams.add('course_id=$courseId');
-      if (lessonId != null) pathParams.add('lesson_id=$lessonId');
-      if (difficultyLevel != null) {
-        pathParams.add('difficulty_level=$difficultyLevel');
-      }
-      if (tag != null) pathParams.add('tag=$tag');
-      if (search != null) pathParams.add('search=$search');
-
-      final queryString = pathParams.isEmpty ? '' : '?${pathParams.join('&')}';
-      final response = await apiClient.get('/vocabulary/items$queryString');
-
-      final data = response['data'];
-      if (data is! List<dynamic>) {
-        throw ServerException('Invalid vocabulary items response');
-      }
+      final uri = Uri(
+        path: '/vocabulary/items',
+        queryParameters: {
+          'limit': limit.toString(),
+          'offset': offset.toString(),
+          if (courseId != null) 'course_id': courseId,
+          if (lessonId != null) 'lesson_id': lessonId,
+          if (difficultyLevel != null) 'difficulty_level': difficultyLevel,
+          if (tag != null) 'tag': tag,
+          if (search != null) 'search': search,
+        },
+      );
+      final response = await apiClient.get(uri.toString());
+      final data = _readList(response);
 
       return data.map((json) {
         if (json is! Map<String, dynamic>) {
@@ -183,7 +188,10 @@ class VocabularyRemoteDataSourceImpl implements VocabularyRemoteDataSource {
         },
       );
       return (cached ?? [])
-          .map((json) => UserVocabularyModel.fromJson(json as Map<String, dynamic>))
+          .map(
+            (json) =>
+                UserVocabularyModel.fromJson(json as Map<String, dynamic>),
+          )
           .toList();
     } on ServerException {
       rethrow;
@@ -256,8 +264,13 @@ class VocabularyRemoteDataSourceImpl implements VocabularyRemoteDataSource {
   Future<List<UserVocabularyModel>> getDeckItems(String deckId) async {
     try {
       final response = await apiClient.get('/vocabulary/decks/$deckId/items');
-      final List<dynamic> data = response as List<dynamic>;
-      return data.map((json) => UserVocabularyModel.fromJson(json)).toList();
+      final data = _readList(response);
+      return data
+          .map(
+            (json) =>
+                UserVocabularyModel.fromJson(json as Map<String, dynamic>),
+          )
+          .toList();
     } on ServerException {
       rethrow;
     } catch (e) {
diff --git a/flutter-app/lib/features/vocabulary/domain/entities/quiz_question_entity.dart b/flutter-app/lib/features/vocabulary/domain/entities/quiz_question_entity.dart
new file mode 100644
index 00000000..516b4480
--- /dev/null
+++ b/flutter-app/lib/features/vocabulary/domain/entities/quiz_question_entity.dart
@@ -0,0 +1,37 @@
+import 'package:lexilingo_app/features/vocabulary/domain/entities/review_session_entity.dart';
+
+/// Direction a quiz question tests the word in.
+/// - [termToMeaning]: show the English term, pick its meaning.
+/// - [meaningToTerm]: show the meaning, pick the English term.
+enum QuizDirection { termToMeaning, meaningToTerm }
+
+/// One selectable answer in a multiple-choice quiz question.
+class QuizOption {
+  final String text;
+  final bool isCorrect;
+
+  const QuizOption({required this.text, required this.isCorrect});
+}
+
+/// A single Quizlet-style multiple-choice question generated from a due word.
+/// Each question is tied back to its [card] so the result can feed FSRS.
+class QuizQuestionEntity {
+  final ReviewCardEntity card;
+  final QuizDirection direction;
+  final String prompt;
+  final List<QuizOption> options;
+
+  const QuizQuestionEntity({
+    required this.card,
+    required this.direction,
+    required this.prompt,
+    required this.options,
+  });
+
+  String get vocabularyId => card.userVocabulary.vocabularyId;
+
+  int? get correctIndex {
+    final i = options.indexWhere((o) => o.isCorrect);
+    return i >= 0 ? i : null;
+  }
+}
diff --git a/flutter-app/lib/features/vocabulary/presentation/pages/vocab_library_page.dart b/flutter-app/lib/features/vocabulary/presentation/pages/vocab_library_page.dart
index 34625dfc..b34a1bcd 100644
--- a/flutter-app/lib/features/vocabulary/presentation/pages/vocab_library_page.dart
+++ b/flutter-app/lib/features/vocabulary/presentation/pages/vocab_library_page.dart
@@ -9,6 +9,12 @@ import 'package:lexilingo_app/features/vocabulary/presentation/widgets/vocab_wor
 import 'package:lexilingo_app/core/theme/app_theme.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/providers/flashcard_provider.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/screens/flashcard_review_screen.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/providers/quiz_provider.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/screens/quiz_review_screen.dart';
+import 'package:lexilingo_app/features/vocabulary/vocabulary_di.dart' as vocab_di;
+
+/// Review modes offered before launching a deck/topic study session.
+enum _ReviewMode { quiz, flashcards }
 
 class VocabLibraryPage extends StatefulWidget {
   const VocabLibraryPage({super.key});
@@ -658,7 +664,77 @@ class _VocabLibraryPageState extends State<VocabLibraryPage> {
     );
   }
 
+  /// Ask the user whether to study via quiz or flashcards.
+  Future<_ReviewMode?> _chooseReviewMode(BuildContext context) {
+    return showModalBottomSheet<_ReviewMode>(
+      context: context,
+      backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+      shape: const RoundedRectangleBorder(
+        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
+      ),
+      builder: (sheetContext) => SafeArea(
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            const SizedBox(height: 8),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(20, 12, 20, 4),
+              child: Align(
+                alignment: Alignment.centerLeft,
+                child: Text(
+                  'vocabQuiz.chooseMode'.tr(),
+                  style: const TextStyle(
+                    fontSize: 18,
+                    fontWeight: FontWeight.bold,
+                  ),
+                ),
+              ),
+            ),
+            ListTile(
+              leading: const Icon(Icons.quiz_rounded, color: AppColors.primary),
+              title: Text('vocabQuiz.modeQuizTitle'.tr()),
+              subtitle: Text('vocabQuiz.modeQuizSubtitle'.tr()),
+              onTap: () => Navigator.of(sheetContext).pop(_ReviewMode.quiz),
+            ),
+            ListTile(
+              leading:
+                  const Icon(Icons.style_rounded, color: AppColors.primary),
+              title: Text('vocabQuiz.modeFlashcardTitle'.tr()),
+              subtitle: Text('vocabQuiz.modeFlashcardSubtitle'.tr()),
+              onTap: () =>
+                  Navigator.of(sheetContext).pop(_ReviewMode.flashcards),
+            ),
+            const SizedBox(height: 12),
+          ],
+        ),
+      ),
+    );
+  }
+
+  /// Push the quiz screen with a route-owned provider started by [starter].
+  void _launchQuiz(
+    BuildContext context,
+    Future<void> Function(QuizProvider) starter,
+  ) {
+    Navigator.push(
+      context,
+      MaterialPageRoute(
+        builder: (_) => ChangeNotifierProvider(
+          create: (_) => vocab_di.getIt<QuizProvider>(),
+          child: QuizReviewScreen(sessionStarter: starter),
+        ),
+      ),
+    );
+  }
+
   Future<void> _startDeckStudy(BuildContext context, VocabularyDeck deck) async {
+    final mode = await _chooseReviewMode(context);
+    if (mode == null || !context.mounted) return;
+    if (mode == _ReviewMode.quiz) {
+      _launchQuiz(context, (p) => p.startDeckSession(deckId: deck.id));
+      return;
+    }
+
     final flashcardProvider = Provider.of<FlashcardProvider>(context, listen: false);
 
     showDialog(
@@ -826,6 +902,13 @@ class _VocabLibraryPageState extends State<VocabLibraryPage> {
   }
 
   Future<void> _startTopicStudy(BuildContext context, _TopicConfig topic) async {
+    final mode = await _chooseReviewMode(context);
+    if (mode == null || !context.mounted) return;
+    if (mode == _ReviewMode.quiz) {
+      _launchQuiz(context, (p) => p.startTopicSession(tag: topic.tag));
+      return;
+    }
+
     final flashcardProvider = Provider.of<FlashcardProvider>(context, listen: false);
 
     showDialog(
diff --git a/flutter-app/lib/features/vocabulary/presentation/providers/quiz_provider.dart b/flutter-app/lib/features/vocabulary/presentation/providers/quiz_provider.dart
new file mode 100644
index 00000000..62a71a75
--- /dev/null
+++ b/flutter-app/lib/features/vocabulary/presentation/providers/quiz_provider.dart
@@ -0,0 +1,486 @@
+import 'dart:math';
+
+import 'package:flutter/foundation.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/quiz_question_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/review_session_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/user_vocabulary_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/vocabulary_item_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/usecases/get_due_vocabulary_usecase.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/usecases/submit_review_usecase.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/repositories/vocabulary_repository.dart';
+
+/// Tracks how a single word performed across its (up to two) quiz questions
+/// so one aggregated FSRS review can be submitted per word.
+class _WordProgress {
+  final ReviewCardEntity card;
+  final int questionCount;
+  int answered = 0;
+  int correct = 0;
+  int timeSpentMs = 0;
+  bool submitted = false;
+
+  _WordProgress({required this.card, required this.questionCount});
+}
+
+/// Quiz Provider (Presentation Layer)
+/// Drives the Quizlet-style multiple-choice review over FSRS-due words.
+/// Generation is client-side; grading is mapped back to [ReviewQuality] and
+/// submitted through the existing review endpoint so activity is logged and
+/// the word is rescheduled by the backend FSRS scheduler.
+class QuizProvider extends ChangeNotifier {
+  static const int _defaultWordTarget = 10;
+  static const int _optionsPerQuestion = 4;
+  static const int _distractorPoolSize = 40;
+
+  final GetDueVocabularyUseCase getDueVocabularyUseCase;
+  final SubmitReviewUseCase submitReviewUseCase;
+  final VocabularyRepository vocabularyRepository;
+
+  QuizProvider({
+    required this.getDueVocabularyUseCase,
+    required this.submitReviewUseCase,
+    required this.vocabularyRepository,
+  });
+
+  final Random _random = Random();
+
+  bool _isLoading = false;
+  String? _errorMessage;
+
+  List<QuizQuestionEntity> _questions = [];
+  int _currentIndex = 0;
+  int? _selectedIndex;
+
+  final Map<String, _WordProgress> _wordProgress = {};
+  final List<Future<void>> _pendingSubmits = [];
+  DateTime? _questionStartTime;
+  DateTime? _startedAt;
+
+  int _wordCount = 0;
+  int _totalXpEarned = 0;
+
+  // Getters
+  bool get isLoading => _isLoading;
+  String? get errorMessage => _errorMessage;
+  bool get hasSession => _questions.isNotEmpty;
+  int get totalQuestions => _questions.length;
+  int get currentQuestionNumber => _currentIndex + 1;
+  int get totalXpEarned => _totalXpEarned;
+
+  QuizQuestionEntity? get currentQuestion =>
+      _currentIndex < _questions.length ? _questions[_currentIndex] : null;
+
+  int? get selectedIndex => _selectedIndex;
+  bool get isAnswered => _selectedIndex != null;
+  bool get isComplete => hasSession && _currentIndex >= _questions.length;
+
+  double get progress =>
+      _questions.isEmpty ? 0.0 : _currentIndex / _questions.length;
+
+  /// Number of words whose every question was answered correctly.
+  int get wordsMastered =>
+      _wordProgress.values.where((w) => w.correct == w.questionCount).length;
+
+  /// Load due words and build the question deck.
+  Future<void> startQuizSession({int wordTarget = _defaultWordTarget}) async {
+    _reset();
+    _isLoading = true;
+    _errorMessage = null;
+    notifyListeners();
+
+    try {
+      final dueResult = await getDueVocabularyUseCase(
+        GetDueVocabularyParams(limit: wordTarget * 2),
+      );
+
+      await dueResult.fold(
+        (failure) async {
+          _errorMessage = failure.message;
+          _isLoading = false;
+          notifyListeners();
+        },
+        (dueList) async {
+          if (dueList.isEmpty) {
+            _errorMessage = 'No vocabulary due for review!';
+            _isLoading = false;
+            notifyListeners();
+            return;
+          }
+
+          final selected = dueList.take(wordTarget).toList();
+          final cards = await _loadCards(selected);
+          await _finalizeWithCards(cards);
+        },
+      );
+    } catch (e) {
+      _errorMessage = 'Unexpected error: $e';
+      _isLoading = false;
+      notifyListeners();
+    }
+  }
+
+  /// Quiz the words inside a custom deck.
+  Future<void> startDeckSession({
+    required String deckId,
+    int limit = _defaultWordTarget,
+  }) async {
+    _reset();
+    _isLoading = true;
+    _errorMessage = null;
+    notifyListeners();
+
+    try {
+      final result = await vocabularyRepository.getDeckItems(deckId);
+      await result.fold(
+        (failure) async {
+          _errorMessage = failure.message;
+          _isLoading = false;
+          notifyListeners();
+        },
+        (deckItems) async {
+          if (deckItems.isEmpty) {
+            _errorMessage = 'No vocabulary found in this deck!';
+            _isLoading = false;
+            notifyListeners();
+            return;
+          }
+          final cards = await _loadCards(deckItems.take(limit).toList());
+          await _finalizeWithCards(cards);
+        },
+      );
+    } catch (e) {
+      _errorMessage = 'Unexpected error: $e';
+      _isLoading = false;
+      notifyListeners();
+    }
+  }
+
+  /// Quiz the words belonging to a topic (tag), adding them to the user's
+  /// collection on the fly so reviews can be persisted.
+  Future<void> startTopicSession({
+    required String tag,
+    int limit = _defaultWordTarget,
+  }) async {
+    _reset();
+    _isLoading = true;
+    _errorMessage = null;
+    notifyListeners();
+
+    try {
+      final itemsResult = await vocabularyRepository.getVocabularyItems(
+        tag: tag,
+        limit: limit,
+      );
+      await itemsResult.fold(
+        (failure) async {
+          _errorMessage = failure.message;
+          _isLoading = false;
+          notifyListeners();
+        },
+        (vocabItems) async {
+          if (vocabItems.isEmpty) {
+            _errorMessage = 'No vocabulary found for topic: $tag';
+            _isLoading = false;
+            notifyListeners();
+            return;
+          }
+
+          final collectionResult =
+              await vocabularyRepository.getUserCollection(limit: 200);
+          final collectionMap = collectionResult.fold(
+            (failure) => <String, UserVocabularyEntity>{},
+            (collection) => {for (final uc in collection) uc.vocabularyId: uc},
+          );
+
+          final cardFutures = vocabItems.map((item) async {
+            var userVocab = collectionMap[item.id];
+            if (userVocab == null) {
+              final added = await vocabularyRepository.addToCollection(item.id);
+              userVocab = added.fold((failure) => null, (uv) => uv);
+            }
+            if (userVocab == null) return null;
+            return ReviewCardEntity(
+              userVocabulary: userVocab,
+              vocabularyItem: item,
+            );
+          });
+          final cards =
+              (await Future.wait(cardFutures)).whereType<ReviewCardEntity>().toList();
+          await _finalizeWithCards(cards);
+        },
+      );
+    } catch (e) {
+      _errorMessage = 'Unexpected error: $e';
+      _isLoading = false;
+      notifyListeners();
+    }
+  }
+
+  /// Build the distractor pool and question deck from prepared cards, then
+  /// publish the session (or an error when nothing usable was produced).
+  Future<void> _finalizeWithCards(List<ReviewCardEntity> cards) async {
+    if (cards.isEmpty) {
+      _errorMessage = 'Failed to load vocabulary items';
+      _isLoading = false;
+      notifyListeners();
+      return;
+    }
+
+    final pool = await _loadDistractorPool(cards);
+    _buildQuestions(cards, pool);
+
+    if (_questions.isEmpty) {
+      _errorMessage = 'Not enough vocabulary to build a quiz yet';
+      _isLoading = false;
+      notifyListeners();
+      return;
+    }
+
+    _wordCount = cards.length;
+    _startedAt = DateTime.now();
+    _questionStartTime = DateTime.now();
+    _isLoading = false;
+    notifyListeners();
+  }
+
+  Future<List<ReviewCardEntity>> _loadCards(
+    List<UserVocabularyEntity> userVocabs,
+  ) async {
+    final futures = userVocabs.map((uv) async {
+      final result = await vocabularyRepository.getVocabularyItem(
+        uv.vocabularyId,
+      );
+      return result.fold<ReviewCardEntity?>(
+        (failure) => null,
+        (item) => ReviewCardEntity(userVocabulary: uv, vocabularyItem: item),
+      );
+    });
+    final results = await Future.wait(futures);
+    return results.whereType<ReviewCardEntity>().toList();
+  }
+
+  /// Master items used as wrong-answer choices. Falls back to the quiz cards
+  /// themselves when the master list is unavailable.
+  Future<List<VocabularyItemEntity>> _loadDistractorPool(
+    List<ReviewCardEntity> cards,
+  ) async {
+    final pool = <String, VocabularyItemEntity>{
+      for (final c in cards) c.vocabularyItem.id: c.vocabularyItem,
+    };
+
+    final result = await vocabularyRepository.getVocabularyItems(
+      limit: _distractorPoolSize,
+    );
+    result.fold(
+      (failure) => debugPrint('Quiz distractor pool failed: ${failure.message}'),
+      (items) {
+        for (final item in items) {
+          pool[item.id] = item;
+        }
+      },
+    );
+    return pool.values.toList();
+  }
+
+  void _buildQuestions(
+    List<ReviewCardEntity> cards,
+    List<VocabularyItemEntity> pool,
+  ) {
+    final questions = <QuizQuestionEntity>[];
+
+    for (final card in cards) {
+      final built = <QuizQuestionEntity>[];
+      final termToMeaning =
+          _buildQuestion(card, pool, QuizDirection.termToMeaning);
+      if (termToMeaning != null) built.add(termToMeaning);
+      final meaningToTerm =
+          _buildQuestion(card, pool, QuizDirection.meaningToTerm);
+      if (meaningToTerm != null) built.add(meaningToTerm);
+
+      if (built.isNotEmpty) {
+        _wordProgress[card.userVocabulary.id] = _WordProgress(
+          card: card,
+          questionCount: built.length,
+        );
+        questions.addAll(built);
+      }
+    }
+
+    _questions = _interleave(questions);
+  }
+
+  QuizQuestionEntity? _buildQuestion(
+    ReviewCardEntity card,
+    List<VocabularyItemEntity> pool,
+    QuizDirection direction,
+  ) {
+    final item = card.vocabularyItem;
+    final correctWord = item.word.trim();
+    final correctMeaning = _meaningOf(item);
+    if (correctWord.isEmpty || correctMeaning.isEmpty) return null;
+
+    final String prompt;
+    final String correctText;
+    final List<String> distractorSource;
+
+    if (direction == QuizDirection.termToMeaning) {
+      prompt = correctWord;
+      correctText = correctMeaning;
+      distractorSource = pool
+          .where((p) => p.id != item.id)
+          .map(_meaningOf)
+          .where((m) => m.isNotEmpty && m != correctMeaning)
+          .toList();
+    } else {
+      prompt = correctMeaning;
+      correctText = correctWord;
+      distractorSource = pool
+          .where((p) => p.id != item.id)
+          .map((p) => p.word.trim())
+          .where((w) => w.isNotEmpty && w != correctWord)
+          .toList();
+    }
+
+    final distractors = _pickDistinct(distractorSource, _optionsPerQuestion - 1);
+    if (distractors.isEmpty) return null; // need at least one wrong choice
+
+    final options = <QuizOption>[
+      QuizOption(text: correctText, isCorrect: true),
+      ...distractors.map((d) => QuizOption(text: d, isCorrect: false)),
+    ]..shuffle(_random);
+
+    return QuizQuestionEntity(
+      card: card,
+      direction: direction,
+      prompt: prompt,
+      options: options,
+    );
+  }
+
+  String _meaningOf(VocabularyItemEntity item) {
+    final definition = item.definition.trim();
+    return definition;
+  }
+
+  List<String> _pickDistinct(List<String> source, int count) {
+    final unique = source.toSet().toList()..shuffle(_random);
+    return unique.take(count).toList();
+  }
+
+  /// Spread a word's two questions apart so the answer isn't shown back-to-back.
+  List<QuizQuestionEntity> _interleave(List<QuizQuestionEntity> questions) {
+    final byWord = <String, List<QuizQuestionEntity>>{};
+    for (final q in questions) {
+      byWord.putIfAbsent(q.card.userVocabulary.id, () => []).add(q);
+    }
+
+    final result = <QuizQuestionEntity>[];
+    var added = true;
+    var round = 0;
+    while (added) {
+      added = false;
+      for (final group in byWord.values) {
+        if (round < group.length) {
+          result.add(group[round]);
+          added = true;
+        }
+      }
+      round++;
+    }
+    return result;
+  }
+
+  /// Record the user's choice. UI feedback is shown immediately; the word's
+  /// review is submitted in the background once all its questions are answered.
+  void answer(int optionIndex) {
+    if (_selectedIndex != null) return;
+    final question = currentQuestion;
+    if (question == null) return;
+
+    _selectedIndex = optionIndex;
+    final isCorrect = question.options[optionIndex].isCorrect;
+
+    final progress = _wordProgress[question.card.userVocabulary.id];
+    if (progress != null) {
+      progress.answered++;
+      if (isCorrect) progress.correct++;
+      progress.timeSpentMs += _questionStartTime != null
+          ? DateTime.now().difference(_questionStartTime!).inMilliseconds
+          : 0;
+
+      if (progress.answered >= progress.questionCount && !progress.submitted) {
+        progress.submitted = true;
+        _pendingSubmits.add(_submitWord(progress));
+      }
+    }
+
+    notifyListeners();
+  }
+
+  /// Await any in-flight review submissions so the summary reflects all XP.
+  Future<void> finishPending() async {
+    if (_pendingSubmits.isEmpty) return;
+    await Future.wait(_pendingSubmits);
+    _pendingSubmits.clear();
+  }
+
+  Future<void> _submitWord(_WordProgress progress) async {
+    final quality = _qualityFor(progress);
+    final result = await submitReviewUseCase(
+      SubmitReviewParams(
+        userVocabularyId: progress.card.userVocabulary.id,
+        quality: quality,
+        timeSpentMs: progress.timeSpentMs,
+      ),
+    );
+    result.fold(
+      (failure) => debugPrint('Quiz review submit failed: ${failure.message}'),
+      (review) => _totalXpEarned += review.xpEarned,
+    );
+  }
+
+  ReviewQuality _qualityFor(_WordProgress progress) {
+    if (progress.correct >= progress.questionCount) return ReviewQuality.easy;
+    if (progress.correct > 0) return ReviewQuality.good;
+    return ReviewQuality.incorrect;
+  }
+
+  /// Advance to the next question (or completion).
+  void next() {
+    if (_selectedIndex == null) return;
+    _selectedIndex = null;
+    _currentIndex++;
+    _questionStartTime = DateTime.now();
+    notifyListeners();
+  }
+
+  /// Build a session summary compatible with the shared complete screen.
+  ReviewSessionEntity buildSummary() {
+    return ReviewSessionEntity(
+      cards: const [],
+      startedAt: _startedAt ?? DateTime.now(),
+      completedAt: DateTime.now(),
+      totalCards: _wordCount,
+      reviewedCards: _wordCount,
+      correctCount: wordsMastered,
+      totalXpEarned: _totalXpEarned,
+    );
+  }
+
+  void clearError() {
+    _errorMessage = null;
+    notifyListeners();
+  }
+
+  void _reset() {
+    _questions = [];
+    _currentIndex = 0;
+    _selectedIndex = null;
+    _wordProgress.clear();
+    _pendingSubmits.clear();
+    _questionStartTime = null;
+    _startedAt = null;
+    _wordCount = 0;
+    _totalXpEarned = 0;
+  }
+}
diff --git a/flutter-app/lib/features/vocabulary/presentation/screens/quiz_review_screen.dart b/flutter-app/lib/features/vocabulary/presentation/screens/quiz_review_screen.dart
new file mode 100644
index 00000000..bf6cf466
--- /dev/null
+++ b/flutter-app/lib/features/vocabulary/presentation/screens/quiz_review_screen.dart
@@ -0,0 +1,367 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/widgets.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/quiz_question_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/providers/quiz_provider.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/screens/session_complete_screen.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/widgets/quiz_option_card.dart';
+
+/// Quizlet-style multiple-choice review over FSRS-due words.
+/// Tests each word in both directions (term ↔ meaning); results feed FSRS.
+class QuizReviewScreen extends StatefulWidget {
+  /// How the session is started. Defaults to FSRS-due words; deck/topic
+  /// callers pass their own loader.
+  final Future<void> Function(QuizProvider)? sessionStarter;
+
+  const QuizReviewScreen({super.key, this.sessionStarter});
+
+  @override
+  State<QuizReviewScreen> createState() => _QuizReviewScreenState();
+}
+
+class _QuizReviewScreenState extends State<QuizReviewScreen> {
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      final provider = context.read<QuizProvider>();
+      if (!provider.hasSession && !provider.isLoading) {
+        (widget.sessionStarter ?? (p) => p.startQuizSession())(provider);
+      }
+    });
+  }
+
+  Future<void> _handleAdvance(QuizProvider provider) async {
+    final wasLast = provider.currentQuestionNumber >= provider.totalQuestions;
+    provider.next();
+    if (wasLast) {
+      await provider.finishPending();
+      if (!mounted) return;
+      Navigator.of(context).pushReplacement(
+        MaterialPageRoute(
+          builder: (_) =>
+              SessionCompleteScreen(session: provider.buildSummary()),
+        ),
+      );
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+      appBar: AppBar(
+        backgroundColor: Colors.transparent,
+        elevation: 0,
+        leading: IconButton(
+          icon: const Icon(Icons.close),
+          onPressed: () => _showExitDialog(context),
+        ),
+        title: Consumer<QuizProvider>(
+          builder: (context, provider, _) {
+            if (!provider.hasSession) return const SizedBox.shrink();
+            return Text(
+              '${provider.currentQuestionNumber} / ${provider.totalQuestions}',
+              style: const TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
+            );
+          },
+        ),
+        centerTitle: true,
+      ),
+      body: Consumer<QuizProvider>(
+        builder: (context, provider, child) {
+          if (provider.isLoading && !provider.hasSession) {
+            return LoadingScreen(message: 'vocabQuiz.loading'.tr());
+          }
+
+          if (provider.errorMessage != null) {
+            return _ErrorState(
+              message: provider.errorMessage!,
+              onRetry: () {
+                provider.clearError();
+                (widget.sessionStarter ?? (p) => p.startQuizSession())(
+                  provider,
+                );
+              },
+            );
+          }
+
+          final question = provider.currentQuestion;
+          if (question == null) {
+            return Center(child: Text('vocabQuiz.empty'.tr()));
+          }
+
+          return _QuizBody(
+            provider: provider,
+            question: question,
+            onAdvance: () => _handleAdvance(provider),
+          );
+        },
+      ),
+    );
+  }
+
+  void _showExitDialog(BuildContext context) {
+    showDialog(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: Text('vocabQuiz.exitTitle'.tr()),
+        content: Text('vocabQuiz.exitMessage'.tr()),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: Text('common.cancel'.tr()),
+          ),
+          TextButton(
+            onPressed: () {
+              Navigator.of(dialogContext).pop();
+              Navigator.of(context).pop();
+            },
+            child: Text(
+              'lesson.exit'.tr(),
+              style: const TextStyle(color: AppColors.errorBright),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _QuizBody extends StatelessWidget {
+  final QuizProvider provider;
+  final QuizQuestionEntity question;
+  final VoidCallback onAdvance;
+
+  const _QuizBody({
+    required this.provider,
+    required this.question,
+    required this.onAdvance,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final answered = provider.isAnswered;
+    final isTerm = question.direction == QuizDirection.termToMeaning;
+    final promptLabel =
+        isTerm ? 'vocabQuiz.term'.tr() : 'vocabQuiz.definition'.tr();
+
+    return Column(
+      children: [
+        // Progress bar
+        Padding(
+          padding: const EdgeInsets.fromLTRB(20, 0, 20, 8),
+          child: ClipRRect(
+            borderRadius: BorderRadius.circular(8),
+            child: LinearProgressIndicator(
+              value: provider.progress,
+              minHeight: 8,
+              backgroundColor: theme.colorScheme.surfaceContainerHighest,
+              valueColor:
+                  const AlwaysStoppedAnimation(AppColors.greenSuccessBright),
+            ),
+          ),
+        ),
+
+        Expanded(
+          child: ListView(
+            padding: const EdgeInsets.fromLTRB(20, 12, 20, 24),
+            children: [
+              // Prompt card
+              Container(
+                width: double.infinity,
+                padding: const EdgeInsets.all(24),
+                decoration: BoxDecoration(
+                  color: theme.brightness == Brightness.dark
+                      ? AppColors.surfaceDarkMuted
+                      : Colors.white,
+                  borderRadius: BorderRadius.circular(20),
+                  border: Border.all(color: theme.colorScheme.outlineVariant),
+                ),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      promptLabel,
+                      style: TextStyle(
+                        fontSize: 13,
+                        fontWeight: FontWeight.w600,
+                        letterSpacing: 0.4,
+                        color: theme.colorScheme.onSurfaceVariant,
+                      ),
+                    ),
+                    const SizedBox(height: 12),
+                    Text(
+                      question.prompt,
+                      style: TextStyle(
+                        fontSize: isTerm ? 28 : 20,
+                        height: 1.4,
+                        fontWeight:
+                            isTerm ? FontWeight.bold : FontWeight.w500,
+                        color: theme.colorScheme.onSurface,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+
+              const SizedBox(height: 24),
+
+              Text(
+                'vocabQuiz.chooseCorrect'.tr(),
+                style: TextStyle(
+                  fontSize: 14,
+                  fontWeight: FontWeight.w600,
+                  color: theme.colorScheme.onSurfaceVariant,
+                ),
+              ),
+              const SizedBox(height: 8),
+
+              ...List.generate(question.options.length, (i) {
+                final option = question.options[i];
+                return QuizOptionCard(
+                  index: i + 1,
+                  text: option.text,
+                  answered: answered,
+                  isCorrect: option.isCorrect,
+                  isSelected: provider.selectedIndex == i,
+                  onTap: answered ? null : () => provider.answer(i),
+                );
+              }),
+            ],
+          ),
+        ),
+
+        // Feedback + continue
+        if (answered) _FeedbackBar(provider: provider, onAdvance: onAdvance),
+      ],
+    );
+  }
+}
+
+class _FeedbackBar extends StatelessWidget {
+  final QuizProvider provider;
+  final VoidCallback onAdvance;
+
+  const _FeedbackBar({required this.provider, required this.onAdvance});
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final selected = provider.selectedIndex;
+    final isCorrect = selected != null &&
+        provider.currentQuestion!.options[selected].isCorrect;
+    final color =
+        isCorrect ? AppColors.greenSuccessBright : AppColors.errorBright;
+    final isLast =
+        provider.currentQuestionNumber >= provider.totalQuestions;
+
+    return Container(
+      padding: EdgeInsets.fromLTRB(
+        20,
+        16,
+        20,
+        16 + MediaQuery.of(context).padding.bottom,
+      ),
+      decoration: BoxDecoration(
+        color: theme.brightness == Brightness.dark
+            ? AppColors.surfaceDarkMuted
+            : Colors.white,
+        borderRadius: const BorderRadius.vertical(top: Radius.circular(24)),
+        boxShadow: [
+          BoxShadow(
+            color: Colors.black.withValues(alpha: 0.05),
+            blurRadius: 10,
+            offset: const Offset(0, -5),
+          ),
+        ],
+      ),
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Row(
+            children: [
+              Icon(
+                isCorrect
+                    ? Icons.check_circle_rounded
+                    : Icons.cancel_rounded,
+                color: color,
+              ),
+              const SizedBox(width: 8),
+              Text(
+                isCorrect
+                    ? 'vocabQuiz.correct'.tr()
+                    : 'vocabQuiz.incorrect'.tr(),
+                style: TextStyle(
+                  fontSize: 16,
+                  fontWeight: FontWeight.bold,
+                  color: color,
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 12),
+          SizedBox(
+            width: double.infinity,
+            child: ElevatedButton(
+              onPressed: onAdvance,
+              style: ElevatedButton.styleFrom(
+                backgroundColor: color,
+                foregroundColor: Colors.white,
+                padding: const EdgeInsets.symmetric(vertical: 16),
+                shape: RoundedRectangleBorder(
+                  borderRadius: BorderRadius.circular(14),
+                ),
+              ),
+              child: Text(
+                isLast
+                    ? 'vocabQuiz.finish'.tr()
+                    : 'vocabQuiz.continueLabel'.tr(),
+                style: const TextStyle(
+                  fontSize: 16,
+                  fontWeight: FontWeight.bold,
+                ),
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _ErrorState extends StatelessWidget {
+  final String message;
+  final VoidCallback onRetry;
+
+  const _ErrorState({required this.message, required this.onRetry});
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(24),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            const Icon(Icons.error_outline, size: 64, color: AppColors.orange),
+            const SizedBox(height: 16),
+            Text(
+              message,
+              textAlign: TextAlign.center,
+              style: const TextStyle(fontSize: 16),
+            ),
+            const SizedBox(height: 24),
+            ElevatedButton(
+              onPressed: onRetry,
+              child: Text('vocabQuiz.tryAgain'.tr()),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/vocabulary/presentation/widgets/daily_review_card.dart b/flutter-app/lib/features/vocabulary/presentation/widgets/daily_review_card.dart
index aed2678a..a77158a7 100644
--- a/flutter-app/lib/features/vocabulary/presentation/widgets/daily_review_card.dart
+++ b/flutter-app/lib/features/vocabulary/presentation/widgets/daily_review_card.dart
@@ -2,9 +2,12 @@ import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
+import 'package:lexilingo_app/core/widgets/game_icon.dart';
 import 'package:lexilingo_app/features/vocabulary/domain/repositories/vocabulary_repository.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/providers/flashcard_provider.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/providers/quiz_provider.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/screens/flashcard_review_screen.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/screens/quiz_review_screen.dart';
 import 'package:lexilingo_app/features/vocabulary/vocabulary_di.dart'
     as vocab_di;
 
@@ -43,7 +46,7 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
     }
   }
 
-  void _startReview() {
+  void _startFlashcards() {
     Navigator.of(context).push(
       MaterialPageRoute(
         builder: (_) => ChangeNotifierProvider(
@@ -54,6 +57,65 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
     );
   }
 
+  void _startQuiz() {
+    Navigator.of(context).push(
+      MaterialPageRoute(
+        builder: (_) => ChangeNotifierProvider(
+          create: (_) => vocab_di.getIt<QuizProvider>(),
+          child: const QuizReviewScreen(),
+        ),
+      ),
+    );
+  }
+
+  void _startReview() {
+    showModalBottomSheet<void>(
+      context: context,
+      backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+      shape: const RoundedRectangleBorder(
+        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
+      ),
+      builder: (sheetContext) => SafeArea(
+        child: Padding(
+          padding: const EdgeInsets.fromLTRB(20, 20, 20, 24),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Text(
+                'vocabQuiz.chooseMode'.tr(),
+                style: const TextStyle(
+                  fontSize: 18,
+                  fontWeight: FontWeight.bold,
+                ),
+              ),
+              const SizedBox(height: 16),
+              _ReviewModeTile(
+                icon: Icons.quiz_rounded,
+                title: 'vocabQuiz.modeQuizTitle'.tr(),
+                subtitle: 'vocabQuiz.modeQuizSubtitle'.tr(),
+                onTap: () {
+                  Navigator.of(sheetContext).pop();
+                  _startQuiz();
+                },
+              ),
+              const SizedBox(height: 12),
+              _ReviewModeTile(
+                icon: Icons.style_rounded,
+                title: 'vocabQuiz.modeFlashcardTitle'.tr(),
+                subtitle: 'vocabQuiz.modeFlashcardSubtitle'.tr(),
+                onTap: () {
+                  Navigator.of(sheetContext).pop();
+                  _startFlashcards();
+                },
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
   void _handleCardTap() {
     if (_isLoading) return;
     if (_dueCount > 0) {
@@ -79,8 +141,8 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
         onTap: _handleCardTap,
         borderRadius: BorderRadius.circular(20),
         child: Container(
-          margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
-          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
+          margin: const EdgeInsets.symmetric(horizontal: 20, vertical: 12),
+          padding: const EdgeInsets.all(20),
           decoration: BoxDecoration(
             gradient: LinearGradient(
               colors: [
@@ -92,14 +154,14 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
               begin: Alignment.topLeft,
               end: Alignment.bottomRight,
             ),
-            borderRadius: BorderRadius.circular(16),
+            borderRadius: BorderRadius.circular(20),
             boxShadow: [
               BoxShadow(
                 color: (isDark ? accent : AppColors.primary).withValues(
-                  alpha: 0.25,
+                  alpha: 0.3,
                 ),
-                blurRadius: 8,
-                offset: const Offset(0, 4),
+                blurRadius: 12,
+                offset: const Offset(0, 6),
               ),
             ],
           ),
@@ -107,22 +169,21 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
             children: [
               // Icon
               Container(
-                width: 44,
-                height: 44,
+                width: 60,
+                height: 60,
                 decoration: BoxDecoration(
                   color: Theme.of(
                     context,
                   ).colorScheme.surface.withValues(alpha: 0.2),
-                  borderRadius: BorderRadius.circular(12),
+                  borderRadius: BorderRadius.circular(16),
                 ),
-                child: Icon(
-                  Icons.style,
-                  color: Theme.of(context).colorScheme.surface,
-                  size: 24,
+                child: const AppGameIcon(
+                  GameIcon.flashcards,
+                  size: 32,
                 ),
               ),
 
-              const SizedBox(width: 12),
+              const SizedBox(width: 16),
 
               // Content
               Expanded(
@@ -133,14 +194,14 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
                       'home.dailyReview'.tr(),
                       style: TextStyle(
                         color: Theme.of(context).colorScheme.surface,
-                        fontSize: 15,
+                        fontSize: 18,
                         fontWeight: FontWeight.bold,
                       ),
                     ),
-                    const SizedBox(height: 2),
+                    const SizedBox(height: 4),
                     _isLoading
                         ? const SizedBox(
-                            width: 80,
+                            width: 100,
                             child: LinearProgressIndicator(
                               backgroundColor: Colors.white24,
                               valueColor: AlwaysStoppedAnimation(Colors.white),
@@ -156,7 +217,7 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
                               color: Theme.of(
                                 context,
                               ).colorScheme.surface.withValues(alpha: 0.9),
-                              fontSize: 12,
+                              fontSize: 14,
                             ),
                           ),
                   ],
@@ -167,20 +228,20 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
               if (!_isLoading && _dueCount > 0)
                 Material(
                   color: Theme.of(context).colorScheme.surface,
-                  borderRadius: BorderRadius.circular(8),
+                  borderRadius: BorderRadius.circular(12),
                   child: InkWell(
-                    onTap: _startReview,
-                    borderRadius: BorderRadius.circular(8),
+                    onTap: _handleCardTap,
+                    borderRadius: BorderRadius.circular(12),
                     child: Container(
                       padding: const EdgeInsets.symmetric(
-                        horizontal: 14,
-                        vertical: 8,
+                        horizontal: 20,
+                        vertical: 12,
                       ),
                       child: Text(
                         'home.startReview'.tr(),
                         style: const TextStyle(
                           color: AppColors.slate900,
-                          fontSize: 13,
+                          fontSize: 16,
                           fontWeight: FontWeight.bold,
                         ),
                       ),
@@ -194,3 +255,79 @@ class _DailyReviewCardState extends State<DailyReviewCard> {
     );
   }
 }
+
+class _ReviewModeTile extends StatelessWidget {
+  final IconData icon;
+  final String title;
+  final String subtitle;
+  final VoidCallback onTap;
+
+  const _ReviewModeTile({
+    required this.icon,
+    required this.title,
+    required this.subtitle,
+    required this.onTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final isDark = theme.brightness == Brightness.dark;
+    final accent = AppColorRoles.primary(isDark);
+    return Material(
+      color: isDark ? AppColors.surfaceDarkMuted : Colors.white,
+      borderRadius: BorderRadius.circular(16),
+      child: InkWell(
+        onTap: onTap,
+        borderRadius: BorderRadius.circular(16),
+        child: Container(
+          padding: const EdgeInsets.all(16),
+          decoration: BoxDecoration(
+            borderRadius: BorderRadius.circular(16),
+            border: Border.all(color: theme.colorScheme.outlineVariant),
+          ),
+          child: Row(
+            children: [
+              Container(
+                width: 48,
+                height: 48,
+                decoration: BoxDecoration(
+                  color: accent.withValues(alpha: 0.15),
+                  borderRadius: BorderRadius.circular(12),
+                ),
+                child: Icon(icon, color: accent),
+              ),
+              const SizedBox(width: 14),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      title,
+                      style: const TextStyle(
+                        fontSize: 16,
+                        fontWeight: FontWeight.bold,
+                      ),
+                    ),
+                    const SizedBox(height: 2),
+                    Text(
+                      subtitle,
+                      style: TextStyle(
+                        fontSize: 13,
+                        color: theme.colorScheme.onSurfaceVariant,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+              Icon(
+                Icons.chevron_right_rounded,
+                color: theme.colorScheme.onSurfaceVariant,
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/vocabulary/presentation/widgets/quiz_option_card.dart b/flutter-app/lib/features/vocabulary/presentation/widgets/quiz_option_card.dart
new file mode 100644
index 00000000..01e37cbe
--- /dev/null
+++ b/flutter-app/lib/features/vocabulary/presentation/widgets/quiz_option_card.dart
@@ -0,0 +1,123 @@
+import 'package:flutter/material.dart';
+import 'package:lexilingo_app/core/theme/app_theme.dart';
+
+/// A single multiple-choice option in the vocabulary quiz.
+/// Renders neutral / selected / correct / wrong states after answering.
+class QuizOptionCard extends StatelessWidget {
+  final int index;
+  final String text;
+  final bool answered;
+  final bool isCorrect;
+  final bool isSelected;
+  final VoidCallback? onTap;
+
+  const QuizOptionCard({
+    super.key,
+    required this.index,
+    required this.text,
+    required this.answered,
+    required this.isCorrect,
+    required this.isSelected,
+    this.onTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final isDark = theme.brightness == Brightness.dark;
+    final baseSurface =
+        isDark ? AppColors.surfaceDarkMuted : Colors.white;
+
+    Color borderColor = theme.colorScheme.outlineVariant;
+    Color background = baseSurface;
+    Color numberColor = theme.colorScheme.onSurfaceVariant;
+    Color numberBg = theme.colorScheme.surfaceContainerHighest;
+    IconData? trailingIcon;
+    Color? trailingColor;
+
+    if (answered) {
+      if (isCorrect) {
+        borderColor = AppColors.greenSuccessBright;
+        background = AppColors.greenSuccessBright.withValues(alpha: 0.12);
+        numberColor = Colors.white;
+        numberBg = AppColors.greenSuccessBright;
+        trailingIcon = Icons.check_circle_rounded;
+        trailingColor = AppColors.greenSuccessBright;
+      } else if (isSelected) {
+        borderColor = AppColors.errorBright;
+        background = AppColors.errorBright.withValues(alpha: 0.10);
+        numberColor = Colors.white;
+        numberBg = AppColors.errorBright;
+        trailingIcon = Icons.cancel_rounded;
+        trailingColor = AppColors.errorBright;
+      } else {
+        borderColor = theme.colorScheme.outlineVariant.withValues(alpha: 0.4);
+        background = baseSurface.withValues(alpha: 0.5);
+      }
+    }
+
+    return Semantics(
+      button: true,
+      selected: isSelected,
+      label: text,
+      child: AnimatedContainer(
+        duration: const Duration(milliseconds: 180),
+        curve: Curves.easeOut,
+        margin: const EdgeInsets.symmetric(vertical: 6),
+        child: Material(
+          color: background,
+          borderRadius: BorderRadius.circular(16),
+          child: InkWell(
+            onTap: onTap,
+            borderRadius: BorderRadius.circular(16),
+            child: Container(
+              constraints: const BoxConstraints(minHeight: 64),
+              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
+              decoration: BoxDecoration(
+                borderRadius: BorderRadius.circular(16),
+                border: Border.all(color: borderColor, width: 2),
+              ),
+              child: Row(
+                children: [
+                  Container(
+                    width: 32,
+                    height: 32,
+                    alignment: Alignment.center,
+                    decoration: BoxDecoration(
+                      color: numberBg,
+                      shape: BoxShape.circle,
+                    ),
+                    child: Text(
+                      '$index',
+                      style: TextStyle(
+                        color: numberColor,
+                        fontWeight: FontWeight.bold,
+                        fontSize: 14,
+                      ),
+                    ),
+                  ),
+                  const SizedBox(width: 14),
+                  Expanded(
+                    child: Text(
+                      text,
+                      style: TextStyle(
+                        fontSize: 16,
+                        height: 1.35,
+                        fontWeight: FontWeight.w500,
+                        color: theme.colorScheme.onSurface,
+                      ),
+                    ),
+                  ),
+                  if (trailingIcon != null) ...[
+                    const SizedBox(width: 10),
+                    Icon(trailingIcon, color: trailingColor, size: 24),
+                  ],
+                ],
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter-app/lib/features/vocabulary/presentation/widgets/word_of_day_card.dart b/flutter-app/lib/features/vocabulary/presentation/widgets/word_of_day_card.dart
index 33c6d1bb..ab1e9a70 100644
--- a/flutter-app/lib/features/vocabulary/presentation/widgets/word_of_day_card.dart
+++ b/flutter-app/lib/features/vocabulary/presentation/widgets/word_of_day_card.dart
@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
 import 'package:lexilingo_app/core/widgets/cefr_badge.dart';
+import 'package:lexilingo_app/core/widgets/game_icon.dart';
 import 'package:lexilingo_app/core/widgets/skeleton_loading.dart';
 import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
 import 'package:lexilingo_app/features/vocabulary/domain/entities/vocabulary_item_entity.dart';
@@ -67,9 +68,8 @@ class _WordCard extends StatelessWidget {
                     shape: BoxShape.circle,
                     color: Colors.white.withValues(alpha: 0.2),
                   ),
-                  child: const Icon(
-                    Icons.auto_awesome_rounded,
-                    color: Colors.white,
+                  child: const AppGameIcon(
+                    GameIcon.sparkle,
                     size: 22,
                   ),
                 ),
diff --git a/flutter-app/lib/features/vocabulary/vocabulary_di.dart b/flutter-app/lib/features/vocabulary/vocabulary_di.dart
index fedf3c27..efcc7986 100644
--- a/flutter-app/lib/features/vocabulary/vocabulary_di.dart
+++ b/flutter-app/lib/features/vocabulary/vocabulary_di.dart
@@ -7,6 +7,7 @@ import 'package:lexilingo_app/features/vocabulary/domain/usecases/submit_review_
 import 'package:lexilingo_app/features/vocabulary/domain/usecases/get_user_collection_usecase.dart';
 import 'package:lexilingo_app/features/vocabulary/domain/usecases/add_to_collection_usecase.dart';
 import 'package:lexilingo_app/features/vocabulary/presentation/providers/flashcard_provider.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/providers/quiz_provider.dart';
 import 'package:lexilingo_app/core/network/api_client.dart';
 
 /// Vocabulary Dependency Injection Setup
@@ -52,4 +53,12 @@ void setupVocabularyDependencies() {
       vocabularyRepository: getIt<VocabularyRepository>(),
     ),
   );
+
+  getIt.registerFactory(
+    () => QuizProvider(
+      getDueVocabularyUseCase: getIt<GetDueVocabularyUseCase>(),
+      submitReviewUseCase: getIt<SubmitReviewUseCase>(),
+      vocabularyRepository: getIt<VocabularyRepository>(),
+    ),
+  );
 }
diff --git a/flutter-app/lib/features/voice/presentation/screens/voice_practice_screen.dart b/flutter-app/lib/features/voice/presentation/screens/voice_practice_screen.dart
index 653224bd..a776cba4 100644
--- a/flutter-app/lib/features/voice/presentation/screens/voice_practice_screen.dart
+++ b/flutter-app/lib/features/voice/presentation/screens/voice_practice_screen.dart
@@ -35,6 +35,8 @@ class VoicePracticeScreen extends StatefulWidget {
 }
 
 class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
+  static const Duration _maxRecordingDuration = Duration(seconds: 20);
+
   final TextEditingController _phraseController = TextEditingController();
   final AudioRecorder _recorder = AudioRecorder();
   final AudioPlayer _player = AudioPlayer();
@@ -45,7 +47,12 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
   bool _isRecording = false;
   bool _isPlaying = false;
   bool _isProcessing = false;
+  bool _isPreparingExample = false;
   bool _hasRecorderPermission = false;
+  Uint8List? _lastRecordingAudioData;
+  String _lastRecordingFilename = 'recording.wav';
+
+  bool get _isBusy => _isProcessing || _isPreparingExample;
 
   // Sample phrases for practice
   final List<String> _samplePhrases = [
@@ -67,7 +74,9 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
 
     _playerStateSub = _player.playerStateStream.listen((state) {
       if (state.processingState == ProcessingState.completed) {
+        if (!mounted) return;
         setState(() => _isPlaying = false);
+        context.read<VoiceProvider>().onPlaybackComplete();
       }
     });
   }
@@ -94,8 +103,17 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
   }
 
   Future<void> _startRecording() async {
+    if (_phraseController.text.trim().isEmpty) {
+      _showError('voice.enterPhraseFirst'.tr());
+      return;
+    }
+
+    if (_isBusy) return;
+    if (_isPlaying) _stopPlaying();
+
     if (!_hasRecorderPermission) {
       await _checkPermission();
+      if (!mounted) return;
       if (!_hasRecorderPermission) {
         _showError('voice.microphonePermissionDenied'.tr());
         return;
@@ -124,13 +142,19 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
         _recordingDuration = Duration.zero;
       });
 
-      context.read<VoiceProvider>().startRecording();
+      final provider = context.read<VoiceProvider>();
+      provider.clearResults();
+      provider.startRecording();
 
       _recordingTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
-        setState(() => _recordingDuration += const Duration(seconds: 1));
-        context.read<VoiceProvider>().updateRecordingDuration(
-          _recordingDuration,
-        );
+        if (!mounted) return;
+        final duration = _recordingDuration + const Duration(seconds: 1);
+        setState(() => _recordingDuration = duration);
+        context.read<VoiceProvider>().updateRecordingDuration(duration);
+        if (duration >= _maxRecordingDuration) {
+          timer.cancel();
+          unawaited(_stopRecording());
+        }
       });
     } catch (e) {
       _showError('voice.failedToStartRecording'.tr(namedArgs: {'error': '$e'}));
@@ -138,26 +162,44 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
   }
 
   Future<void> _stopRecording() async {
+    if (!_isRecording) return;
+
     _recordingTimer?.cancel();
+    setState(() {
+      _isRecording = false;
+      _isProcessing = true;
+    });
 
     try {
       final path = await _recorder.stop();
 
       if (!mounted) return;
 
-      setState(() => _isRecording = false);
-
       if (path != null) {
         final audioData = await _readRecordedAudio(path);
+        if (!mounted) return;
         if (audioData != null && audioData.isNotEmpty) {
-          await _assessPronunciation(audioData, 'recording.wav');
+          _lastRecordingAudioData = audioData;
+          _lastRecordingFilename = 'recording.wav';
+          await _assessPronunciation(audioData, _lastRecordingFilename);
         } else {
+          setState(() => _isProcessing = false);
+          context.read<VoiceProvider>().resetState();
           _showError('voice.recordedAudioUnreadable'.tr());
         }
       } else {
+        setState(() => _isProcessing = false);
+        context.read<VoiceProvider>().resetState();
         _showError('voice.noRecordedAudioReturned'.tr());
       }
     } catch (e) {
+      if (mounted) {
+        setState(() {
+          _isRecording = false;
+          _isProcessing = false;
+        });
+        context.read<VoiceProvider>().resetState();
+      }
       _showError('voice.failedToStopRecording'.tr(namedArgs: {'error': '$e'}));
     }
   }
@@ -166,6 +208,12 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
     Uint8List audioData,
     String filename,
   ) async {
+    final targetText = _phraseController.text.trim();
+    if (targetText.isEmpty) {
+      _showError('voice.enterPhraseFirst'.tr());
+      return;
+    }
+
     setState(() => _isProcessing = true);
 
     try {
@@ -173,7 +221,7 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
       await provider.assessPronunciation(
         audioData: audioData,
         filename: filename,
-        targetText: _phraseController.text.trim(),
+        targetText: targetText,
         language: widget.language,
       );
     } catch (e) {
@@ -189,12 +237,18 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
       return;
     }
 
-    setState(() => _isProcessing = true);
+    if (_isPlaying) {
+      _stopPlaying();
+      return;
+    }
+
+    setState(() => _isPreparingExample = true);
 
     final provider = context.read<VoiceProvider>();
     final result = await provider.synthesizeAndPlay(
       text: _phraseController.text.trim(),
     );
+    if (!mounted) return;
 
     if (result != null && result.audioData.isNotEmpty) {
       try {
@@ -214,29 +268,49 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
 
         setState(() {
           _isPlaying = true;
-          _isProcessing = false;
+          _isPreparingExample = false;
         });
       } catch (e) {
-        setState(() => _isProcessing = false);
+        if (!mounted) return;
+        provider.resetState();
+        setState(() => _isPreparingExample = false);
         _showError('voice.failedToPlayAudio'.tr(namedArgs: {'error': '$e'}));
       }
     } else {
-      setState(() => _isProcessing = false);
+      provider.resetState();
+      setState(() => _isPreparingExample = false);
     }
   }
 
   void _stopPlaying() {
     _player.stop();
     setState(() => _isPlaying = false);
+    context.read<VoiceProvider>().onPlaybackComplete();
   }
 
   void _selectRandomPhrase() {
+    if (_isBusy || _isRecording) return;
     final random = (_samplePhrases.toList()..shuffle()).first;
-    _phraseController.text = random;
+    setState(() {
+      _phraseController.text = random;
+      _lastRecordingAudioData = null;
+    });
     context.read<VoiceProvider>().clearResults();
   }
 
+  Future<void> _retryAssessment() async {
+    final audioData = _lastRecordingAudioData;
+    if (audioData == null || audioData.isEmpty) {
+      _showError('voice.noRecordedAudioReturned'.tr());
+      return;
+    }
+
+    context.read<VoiceProvider>().resetState();
+    await _assessPronunciation(audioData, _lastRecordingFilename);
+  }
+
   void _showError(String message) {
+    if (!mounted) return;
     ScaffoldMessenger.of(context).showSnackBar(
       SnackBar(content: Text(message), backgroundColor: AppColors.errorBright),
     );
@@ -258,6 +332,430 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
     return file.readAsBytes();
   }
 
+  Widget _buildGuideCard(BuildContext context, VoiceProvider voiceProvider) {
+    return Container(
+      width: double.infinity,
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        gradient: LinearGradient(
+          colors: [
+            AppColors.primary.withValues(alpha: 0.12),
+            AppColors.accentMint.withValues(alpha: 0.08),
+          ],
+        ),
+        borderRadius: BorderRadius.circular(20),
+        border: Border.all(color: AppColors.primary.withValues(alpha: 0.12)),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Container(
+                width: 42,
+                height: 42,
+                decoration: BoxDecoration(
+                  color: AppColors.primary.withValues(alpha: 0.12),
+                  shape: BoxShape.circle,
+                ),
+                child: Icon(Icons.lightbulb_outline, color: AppColors.primary),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Text(
+                  'voice.instructions'.tr(),
+                  style: Theme.of(context).textTheme.bodyLarge?.copyWith(
+                    height: 1.45,
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 14),
+          Wrap(
+            spacing: 8,
+            runSpacing: 8,
+            children: [
+              _buildStepChip(
+                context,
+                number: 1,
+                icon: Icons.volume_up,
+                label: 'voice.listen'.tr(),
+                active: _isPreparingExample || _isPlaying,
+                done: voiceProvider.lastAudioSynthesis != null,
+              ),
+              _buildStepChip(
+                context,
+                number: 2,
+                icon: Icons.mic,
+                label: 'voice.speak'.tr(),
+                active: _isRecording,
+                done: _lastRecordingAudioData != null,
+              ),
+              _buildStepChip(
+                context,
+                number: 3,
+                icon: Icons.insights,
+                label: 'voice.pronunciation'.tr(),
+                active: _isProcessing,
+                done: voiceProvider.lastPronunciationScore != null,
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildStepChip(
+    BuildContext context, {
+    required int number,
+    required IconData icon,
+    required String label,
+    required bool active,
+    required bool done,
+  }) {
+    final color = done
+        ? AppColors.greenSuccessBright
+        : active
+        ? AppColors.primary
+        : AppColors.textGrey;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: done || active ? 0.12 : 0.08),
+        borderRadius: BorderRadius.circular(999),
+        border: Border.all(color: color.withValues(alpha: 0.22)),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Text(
+            '$number',
+            style: Theme.of(context).textTheme.labelMedium?.copyWith(
+              color: color,
+              fontWeight: FontWeight.bold,
+            ),
+          ),
+          const SizedBox(width: 6),
+          Icon(done ? Icons.check_circle : icon, size: 16, color: color),
+          const SizedBox(width: 6),
+          Text(
+            label,
+            style: Theme.of(context).textTheme.labelMedium?.copyWith(
+              color: color,
+              fontWeight: FontWeight.w700,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildPhraseSection(
+    BuildContext context,
+    VoiceProvider voiceProvider,
+  ) {
+    final selectedPhrase = _phraseController.text.trim();
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        TextField(
+          controller: _phraseController,
+          enabled: !_isRecording && !_isBusy,
+          maxLines: 3,
+          decoration: InputDecoration(
+            labelText: 'voice.phraseToPractice'.tr(),
+            hintText: 'voice.enterPhraseHint'.tr(),
+            filled: true,
+            fillColor: Theme.of(context).cardColor,
+            border: OutlineInputBorder(borderRadius: BorderRadius.circular(16)),
+            prefixIcon: const Icon(Icons.short_text),
+            suffixIcon: IconButton(
+              icon: const Icon(Icons.clear),
+              onPressed: _isRecording || _isBusy
+                  ? null
+                  : () {
+                      _phraseController.clear();
+                      _lastRecordingAudioData = null;
+                      voiceProvider.clearResults();
+                    },
+            ),
+          ),
+          onChanged: (_) {
+            _lastRecordingAudioData = null;
+            voiceProvider.clearResults();
+          },
+        ),
+        const SizedBox(height: 12),
+        SingleChildScrollView(
+          scrollDirection: Axis.horizontal,
+          child: Row(
+            children: _samplePhrases.take(4).map((phrase) {
+              final selected = phrase == selectedPhrase;
+              return Padding(
+                padding: const EdgeInsets.only(right: 8),
+                child: ActionChip(
+                  label: Text(phrase),
+                  avatar: selected ? const Icon(Icons.check, size: 16) : null,
+                  backgroundColor: selected
+                      ? AppColors.primary.withValues(alpha: 0.12)
+                      : Theme.of(context).cardColor,
+                  side: BorderSide(
+                    color: selected
+                        ? AppColors.primary.withValues(alpha: 0.35)
+                        : AppColors.grey300,
+                  ),
+                  onPressed: _isRecording || _isBusy
+                      ? null
+                      : () {
+                          setState(() {
+                            _phraseController.text = phrase;
+                            _lastRecordingAudioData = null;
+                          });
+                          voiceProvider.clearResults();
+                        },
+                ),
+              );
+            }).toList(),
+          ),
+        ),
+      ],
+    );
+  }
+
+  Widget _buildListenControls(BuildContext context) {
+    return Row(
+      children: [
+        Expanded(
+          child: ElevatedButton.icon(
+            onPressed: _isRecording || _isProcessing || _isPreparingExample
+                ? null
+                : (_isPlaying ? _stopPlaying : _playExample),
+            icon: _isPreparingExample
+                ? SizedBox(
+                    width: 18,
+                    height: 18,
+                    child: CircularProgressIndicator(
+                      strokeWidth: 2,
+                      color: Theme.of(context).colorScheme.surface,
+                    ),
+                  )
+                : Icon(_isPlaying ? Icons.stop : Icons.volume_up),
+            label: Text(
+              _isPreparingExample
+                  ? 'voice.processing'.tr()
+                  : (_isPlaying
+                        ? 'voice.stop'.tr()
+                        : 'voice.listenToExample'.tr()),
+            ),
+            style: ElevatedButton.styleFrom(
+              backgroundColor: AppColors.primary,
+              foregroundColor: Colors.white,
+              minimumSize: const Size.fromHeight(50),
+              padding: const EdgeInsets.symmetric(horizontal: 18, vertical: 14),
+              shape: RoundedRectangleBorder(
+                borderRadius: BorderRadius.circular(18),
+              ),
+            ),
+          ),
+        ),
+        const SizedBox(width: 10),
+        IconButton(
+          onPressed: _isRecording || _isBusy ? null : _selectRandomPhrase,
+          icon: const Icon(Icons.shuffle),
+          tooltip: 'voice.randomPhrase'.tr(),
+          style: IconButton.styleFrom(
+            backgroundColor: AppColors.primary.withValues(alpha: 0.1),
+            foregroundColor: AppColors.primary,
+            minimumSize: const Size(50, 50),
+          ),
+        ),
+      ],
+    );
+  }
+
+  Widget _buildRecordingSection(
+    BuildContext context,
+    VoiceProvider voiceProvider,
+  ) {
+    final status = _isProcessing
+        ? 'voice.analyzingPronunciation'.tr()
+        : (_isRecording
+              ? 'voice.recording'.tr()
+              : (voiceProvider.lastPronunciationScore != null
+                    ? 'voice.goodJob'.tr()
+                    : 'voice.tapToRecord'.tr()));
+
+    return Container(
+      width: double.infinity,
+      padding: const EdgeInsets.all(20),
+      decoration: BoxDecoration(
+        color: Theme.of(context).cardColor,
+        borderRadius: BorderRadius.circular(24),
+        border: Border.all(color: AppColors.grey300.withValues(alpha: 0.8)),
+        boxShadow: [
+          BoxShadow(
+            color: AppColors.primary.withValues(alpha: 0.06),
+            blurRadius: 20,
+            offset: const Offset(0, 10),
+          ),
+        ],
+      ),
+      child: Column(
+        children: [
+          Align(
+            alignment: Alignment.centerLeft,
+            child: Text(
+              'voice.yourTurn'.tr(),
+              style: Theme.of(
+                context,
+              ).textTheme.headlineSmall?.copyWith(fontWeight: FontWeight.bold),
+            ),
+          ),
+          const SizedBox(height: 8),
+          Align(
+            alignment: Alignment.centerLeft,
+            child: Container(
+              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
+              decoration: BoxDecoration(
+                color:
+                    (_isRecording ? AppColors.errorBright : AppColors.primary)
+                        .withValues(alpha: 0.1),
+                borderRadius: BorderRadius.circular(999),
+              ),
+              child: Text(
+                status,
+                style: Theme.of(context).textTheme.labelMedium?.copyWith(
+                  color: _isRecording
+                      ? AppColors.errorBright
+                      : AppColors.primary,
+                  fontWeight: FontWeight.bold,
+                ),
+              ),
+            ),
+          ),
+          const SizedBox(height: 24),
+          if (!_hasRecorderPermission)
+            ElevatedButton.icon(
+              onPressed: _checkPermission,
+              icon: const Icon(Icons.mic_off),
+              label: Text('voice.grantMicrophonePermission'.tr()),
+              style: ElevatedButton.styleFrom(
+                backgroundColor: AppColors.orange,
+                foregroundColor: Colors.white,
+              ),
+            )
+          else if (_isProcessing)
+            _buildProcessingState(context)
+          else
+            RecordButton(
+              isRecording: _isRecording,
+              isProcessing: false,
+              recordingDuration: _recordingDuration,
+              maxDuration: _maxRecordingDuration,
+              onPressed: _isRecording ? _stopRecording : _startRecording,
+            ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildProcessingState(BuildContext context) {
+    return Column(
+      children: [
+        const LottieAnimationWidget.pulse(width: 92, height: 92),
+        const SizedBox(height: 6),
+        Text(
+          'voice.analyzingPronunciation'.tr(),
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+            color: AppColors.textGrey,
+            fontWeight: FontWeight.w600,
+          ),
+        ),
+      ],
+    );
+  }
+
+  Widget _buildErrorCard(BuildContext context, VoiceProvider voiceProvider) {
+    final canRetry =
+        _lastRecordingAudioData != null && !_isBusy && !_isRecording;
+
+    return Container(
+      width: double.infinity,
+      padding: const EdgeInsets.all(14),
+      decoration: BoxDecoration(
+        color: AppColors.errorBg,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(
+          color: AppColors.errorBright.withValues(alpha: 0.45),
+        ),
+      ),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.center,
+        children: [
+          Icon(Icons.error_outline, color: AppColors.errorBright),
+          const SizedBox(width: 10),
+          Expanded(
+            child: Text(
+              voiceProvider.errorMessage!,
+              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: AppColors.errorDark,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ),
+          if (canRetry)
+            TextButton(
+              onPressed: _retryAssessment,
+              child: Text('voice.tryAgain'.tr()),
+            ),
+          IconButton(
+            onPressed: voiceProvider.resetState,
+            icon: const Icon(Icons.close),
+            color: AppColors.errorDark,
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildTranscriptionCard(
+    BuildContext context,
+    VoiceProvider voiceProvider,
+  ) {
+    return Container(
+      width: double.infinity,
+      padding: const EdgeInsets.all(16),
+      decoration: BoxDecoration(
+        color: Theme.of(context).cardColor,
+        borderRadius: BorderRadius.circular(16),
+        border: Border.all(color: AppColors.grey300),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            'voice.youSaid'.tr(),
+            style: Theme.of(
+              context,
+            ).textTheme.titleSmall?.copyWith(color: AppColors.textGrey),
+          ),
+          const SizedBox(height: 8),
+          Text(
+            voiceProvider.lastTranscription!.text,
+            style: Theme.of(context).textTheme.bodyLarge,
+          ),
+        ],
+      ),
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -266,7 +764,7 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
         actions: [
           IconButton(
             icon: const Icon(Icons.shuffle),
-            onPressed: _selectRandomPhrase,
+            onPressed: _isBusy || _isRecording ? null : _selectRandomPhrase,
             tooltip: 'voice.randomPhrase'.tr(),
           ),
         ],
@@ -276,167 +774,27 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
           return SingleChildScrollView(
             padding: const EdgeInsets.all(20),
             child: Column(
-              crossAxisAlignment: CrossAxisAlignment.center,
+              crossAxisAlignment: CrossAxisAlignment.stretch,
               children: [
-                // Instructions
-                Container(
-                  padding: const EdgeInsets.all(16),
-                  decoration: BoxDecoration(
-                    color: AppColors.primary.withValues(alpha: 0.1),
-                    borderRadius: BorderRadius.circular(12),
-                  ),
-                  child: Row(
-                    children: [
-                      Icon(Icons.lightbulb_outline, color: AppColors.primary),
-                      const SizedBox(width: 12),
-                      Expanded(
-                        child: Text(
-                          'voice.instructions'.tr(),
-                          style: Theme.of(context).textTheme.bodyMedium,
-                        ),
-                      ),
-                    ],
-                  ),
-                ),
+                _buildGuideCard(context, voiceProvider),
                 const SizedBox(height: 24),
-
-                // Phrase input
-                TextField(
-                  controller: _phraseController,
-                  maxLines: 3,
-                  decoration: InputDecoration(
-                    labelText: 'voice.phraseToPractice'.tr(),
-                    hintText: 'voice.enterPhraseHint'.tr(),
-                    border: OutlineInputBorder(
-                      borderRadius: BorderRadius.circular(12),
-                    ),
-                    suffixIcon: IconButton(
-                      icon: const Icon(Icons.clear),
-                      onPressed: () {
-                        _phraseController.clear();
-                        voiceProvider.clearResults();
-                      },
-                    ),
-                  ),
-                  onChanged: (_) => voiceProvider.clearResults(),
-                ),
+                _buildPhraseSection(context, voiceProvider),
+                const SizedBox(height: 18),
+                _buildListenControls(context),
                 const SizedBox(height: 24),
-
-                // Listen to example button
-                ElevatedButton.icon(
-                  onPressed: _isPlaying || _isRecording
-                      ? null
-                      : (_isPlaying ? _stopPlaying : _playExample),
-                  icon: Icon(_isPlaying ? Icons.stop : Icons.volume_up),
-                  label: Text(
-                    _isPlaying
-                        ? 'voice.stop'.tr()
-                        : 'voice.listenToExample'.tr(),
-                  ),
-                  style: ElevatedButton.styleFrom(
-                    backgroundColor: AppColors.primary,
-                    foregroundColor: Colors.white,
-                    padding: const EdgeInsets.symmetric(
-                      horizontal: 24,
-                      vertical: 12,
-                    ),
-                  ),
-                ),
-                const SizedBox(height: 40),
-
-                // Recording section
-                if (!_hasRecorderPermission) ...[
-                  ElevatedButton.icon(
-                    onPressed: _checkPermission,
-                    icon: const Icon(Icons.mic_off),
-                    label: Text('voice.grantMicrophonePermission'.tr()),
-                    style: ElevatedButton.styleFrom(
-                      backgroundColor: AppColors.orange,
-                      foregroundColor: Colors.white,
-                    ),
-                  ),
-                ] else ...[
-                  Text(
-                    'voice.yourTurn'.tr(),
-                    style: Theme.of(context).textTheme.titleLarge?.copyWith(
-                      fontWeight: FontWeight.bold,
-                    ),
-                  ),
-                  const SizedBox(height: 20),
-                  if (_isProcessing) ...[
-                    const LottieAnimationWidget.pulse(width: 88, height: 88),
-                    const SizedBox(height: 4),
-                    Text(
-                      'voice.analyzingPronunciation'.tr(),
-                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
-                        color: AppColors.textGrey,
-                      ),
-                    ),
-                    const SizedBox(height: 16),
-                  ],
-                  RecordButton(
-                    isRecording: _isRecording,
-                    isProcessing: _isProcessing,
-                    recordingDuration: _recordingDuration,
-                    onPressed: _isRecording ? _stopRecording : _startRecording,
-                  ),
-                ],
-                const SizedBox(height: 32),
-
-                // Error message
+                _buildRecordingSection(context, voiceProvider),
                 if (voiceProvider.hasError &&
-                    voiceProvider.errorMessage != null)
-                  Container(
-                    padding: const EdgeInsets.all(12),
-                    decoration: BoxDecoration(
-                      color: Colors.red.shade50,
-                      borderRadius: BorderRadius.circular(8),
-                      border: Border.all(color: Colors.red.shade200),
-                    ),
-                    child: Row(
-                      children: [
-                        Icon(Icons.error_outline, color: AppColors.errorBright),
-                        const SizedBox(width: 8),
-                        Expanded(
-                          child: Text(
-                            voiceProvider.errorMessage!,
-                            style: TextStyle(color: Colors.red.shade700),
-                          ),
-                        ),
-                      ],
-                    ),
-                  ),
-
-                // Transcription result
+                    voiceProvider.errorMessage != null) ...[
+                  const SizedBox(height: 18),
+                  _buildErrorCard(context, voiceProvider),
+                ],
                 if (voiceProvider.lastTranscription != null &&
                     voiceProvider.lastPronunciationScore == null) ...[
-                  Container(
-                    padding: const EdgeInsets.all(16),
-                    decoration: BoxDecoration(
-                      color: Theme.of(context).cardColor,
-                      borderRadius: BorderRadius.circular(12),
-                      border: Border.all(color: AppColors.grey300),
-                    ),
-                    child: Column(
-                      crossAxisAlignment: CrossAxisAlignment.start,
-                      children: [
-                        Text(
-                          'voice.youSaid'.tr(),
-                          style: Theme.of(context).textTheme.titleSmall
-                              ?.copyWith(color: AppColors.textGrey),
-                        ),
-                        const SizedBox(height: 8),
-                        Text(
-                          voiceProvider.lastTranscription!.text,
-                          style: Theme.of(context).textTheme.bodyLarge,
-                        ),
-                      ],
-                    ),
-                  ),
+                  const SizedBox(height: 18),
+                  _buildTranscriptionCard(context, voiceProvider),
                 ],
-
-                // Pronunciation score
                 if (voiceProvider.lastPronunciationScore != null) ...[
+                  const SizedBox(height: 24),
                   if (voiceProvider.lastPronunciationScore!.overallScore >=
                       80) ...[
                     const LottieAnimationWidget.success(
@@ -457,13 +815,13 @@ class _VoicePracticeScreenState extends State<VoicePracticeScreen> {
                   PronunciationScoreCard(
                     score: voiceProvider.lastPronunciationScore!,
                     onTryAgain: () {
+                      setState(() => _lastRecordingAudioData = null);
                       voiceProvider.clearResults();
                     },
                     onListenExample: _playExample,
                   ),
                 ],
-
-                const SizedBox(height: 40),
+                const SizedBox(height: 28),
               ],
             ),
           );
diff --git a/flutter-app/lib/features/voice/presentation/widgets/record_button.dart b/flutter-app/lib/features/voice/presentation/widgets/record_button.dart
index 65f357da..b843779b 100644
--- a/flutter-app/lib/features/voice/presentation/widgets/record_button.dart
+++ b/flutter-app/lib/features/voice/presentation/widgets/record_button.dart
@@ -1,7 +1,6 @@
 import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
-import 'package:lexilingo_app/core/widgets/lottie_loading_widget.dart';
 
 /// Record Button Widget
 /// Animated button for recording audio
@@ -10,6 +9,7 @@ class RecordButton extends StatefulWidget {
   final bool isProcessing;
   final VoidCallback onPressed;
   final Duration recordingDuration;
+  final Duration? maxDuration;
 
   const RecordButton({
     super.key,
@@ -17,6 +17,7 @@ class RecordButton extends StatefulWidget {
     required this.isProcessing,
     required this.onPressed,
     this.recordingDuration = Duration.zero,
+    this.maxDuration,
   });
 
   @override
@@ -65,6 +66,16 @@ class _RecordButtonState extends State<RecordButton>
 
   @override
   Widget build(BuildContext context) {
+    final maxDuration = widget.maxDuration;
+    final recordingLabel = widget.isRecording && maxDuration != null
+        ? '${_formatDuration(widget.recordingDuration)} / ${_formatDuration(maxDuration)}'
+        : _formatDuration(widget.recordingDuration);
+    final progress = maxDuration == null || maxDuration.inMilliseconds == 0
+        ? null
+        : (widget.recordingDuration.inMilliseconds / maxDuration.inMilliseconds)
+              .clamp(0.0, 1.0)
+              .toDouble();
+
     return Column(
       mainAxisSize: MainAxisSize.min,
       children: [
@@ -72,7 +83,7 @@ class _RecordButtonState extends State<RecordButton>
           Padding(
             padding: const EdgeInsets.only(bottom: 12),
             child: Text(
-              _formatDuration(widget.recordingDuration),
+              recordingLabel,
               style: Theme.of(context).textTheme.titleMedium?.copyWith(
                 color: AppColors.errorBright,
                 fontWeight: FontWeight.bold,
@@ -109,12 +120,10 @@ class _RecordButtonState extends State<RecordButton>
                     ],
                   ),
                   child: widget.isProcessing
-                      ? Center(
-                          child: SizedBox(
-                            width: 32,
-                            height: 32,
-                            child: LottieLoadingWidget.tiny(),
-                          ),
+                      ? Icon(
+                          Icons.hourglass_top,
+                          color: Theme.of(context).colorScheme.surface,
+                          size: 32,
                         )
                       : Icon(
                           widget.isRecording ? Icons.stop : Icons.mic,
@@ -126,6 +135,23 @@ class _RecordButtonState extends State<RecordButton>
             },
           ),
         ),
+        if (widget.isRecording && progress != null) ...[
+          const SizedBox(height: 14),
+          SizedBox(
+            width: 132,
+            child: ClipRRect(
+              borderRadius: BorderRadius.circular(999),
+              child: LinearProgressIndicator(
+                value: progress,
+                minHeight: 6,
+                backgroundColor: AppColors.errorBright.withValues(alpha: 0.14),
+                valueColor: const AlwaysStoppedAnimation<Color>(
+                  AppColors.errorBright,
+                ),
+              ),
+            ),
+          ),
+        ],
         const SizedBox(height: 12),
         Text(
           widget.isProcessing
diff --git a/flutter-app/lib/main.dart b/flutter-app/lib/main.dart
index 559932bb..ad243821 100644
--- a/flutter-app/lib/main.dart
+++ b/flutter-app/lib/main.dart
@@ -31,6 +31,7 @@ import 'package:lexilingo_app/core/services/locale_service.dart';
 import 'package:lexilingo_app/core/services/language_flag_cache.dart';
 import 'package:lexilingo_app/core/services/sync_queue_lifecycle_runner.dart';
 import 'package:lexilingo_app/core/network/api_client.dart';
+import 'package:lexilingo_app/features/achievements/presentation/screens/achievements_screen.dart';
 import 'package:lexilingo_app/features/achievements/presentation/providers/achievement_provider.dart';
 import 'package:lexilingo_app/features/auth/presentation/providers/auth_provider.dart';
 import 'package:lexilingo_app/features/auth/presentation/pages/reset_password_page.dart';
@@ -40,7 +41,9 @@ import 'package:lexilingo_app/features/chat/presentation/providers/story_provide
 import 'package:lexilingo_app/features/course/presentation/providers/course_provider.dart';
 import 'package:lexilingo_app/features/gamification/presentation/providers/gamification_provider.dart';
 import 'package:lexilingo_app/features/learning/presentation/providers/learning_provider.dart';
+import 'package:lexilingo_app/features/level/presentation/pages/placement_test_page.dart';
 import 'package:lexilingo_app/features/level/presentation/providers/level_provider.dart';
+import 'package:lexilingo_app/features/level/presentation/providers/placement_test_provider.dart';
 import 'package:lexilingo_app/features/level/presentation/providers/proficiency_provider.dart';
 import 'package:lexilingo_app/features/notifications/presentation/providers/notification_provider.dart';
 import 'package:lexilingo_app/features/profile/presentation/providers/profile_provider.dart';
@@ -55,11 +58,13 @@ import 'package:lexilingo_app/features/vocabulary/vocabulary_di.dart'
 import 'package:lexilingo_app/features/user/presentation/providers/user_provider.dart';
 import 'package:lexilingo_app/features/user/presentation/providers/settings_provider.dart';
 import 'package:lexilingo_app/features/home/presentation/providers/home_provider.dart';
+import 'package:lexilingo_app/features/home/presentation/pages/today_plan_page.dart';
 import 'package:lexilingo_app/features/voice/presentation/providers/voice_provider.dart';
 import 'package:lexilingo_app/features/voice/presentation/providers/tts_settings_provider.dart';
 import 'package:lexilingo_app/features/voice/presentation/providers/speech_recognition_provider.dart';
 import 'package:lexilingo_app/features/progress/presentation/providers/streak_provider.dart';
 import 'package:lexilingo_app/features/progress/presentation/providers/daily_challenges_provider.dart';
+import 'package:lexilingo_app/features/social/presentation/screens/social_screen.dart';
 import 'package:lexilingo_app/features/youtube/presentation/providers/youtube_provider.dart';
 import 'package:lexilingo_app/features/youtube/presentation/screens/youtube_explore_screen.dart';
 import 'package:lexilingo_app/features/youtube/presentation/screens/youtube_player_screen.dart';
@@ -78,8 +83,13 @@ import 'package:lexilingo_app/features/podcast/presentation/screens/podcast_play
 import 'package:lexilingo_app/features/podcast/domain/entities/podcast_entities.dart';
 import 'package:lexilingo_app/features/books/presentation/providers/book_provider.dart';
 import 'package:lexilingo_app/features/books/presentation/screens/book_library_screen.dart';
+import 'package:lexilingo_app/features/mistakes/presentation/pages/mistake_notebook_page.dart';
+import 'package:lexilingo_app/features/offline/presentation/pages/offline_sync_center_page.dart';
+import 'package:lexilingo_app/features/practice/presentation/pages/practice_lab_page.dart';
+import 'package:lexilingo_app/features/premium/presentation/screens/paywall_screen.dart';
 import 'package:lexilingo_app/features/lexi_chat/presentation/providers/lexi_chat_provider.dart';
 import 'package:lexilingo_app/features/lexi_chat/presentation/pages/lexi_chat_page.dart';
+import 'package:lexilingo_app/features/home/presentation/pages/main_screen.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -452,6 +462,19 @@ class _LexiLingoAppState extends State<LexiLingoApp>
               },
               // Phase 3: English Games
               '/games': (context) => const GamesHubScreen(),
+              '/courses': (context) => const MainScreen(initialIndex: 1),
+              '/today-plan': (context) => const TodayPlanPage(),
+              '/practice-lab': (context) => const PracticeLabPage(),
+              '/mistake-notebook': (context) => const MistakeNotebookPage(),
+              '/profile': (context) => const MainScreen(initialIndex: 4),
+              '/achievements': (context) => const AchievementsScreen(),
+              '/social': (context) => const SocialScreen(),
+              '/premium': (context) => const PaywallScreen(),
+              '/offline-sync': (context) => const OfflineSyncCenterPage(),
+              '/placement-test': (context) => ChangeNotifierProvider(
+                create: (_) => di.sl<PlacementTestProvider>(),
+                child: const PlacementTestPage(),
+              ),
               '/vocabulary/review': (context) => ChangeNotifierProvider(
                 create: (_) => vocab_di.getIt<FlashcardProvider>(),
                 child: const FlashcardReviewScreen(),
diff --git a/flutter-app/pubspec.lock b/flutter-app/pubspec.lock
index 8a302ccb..49f76934 100644
--- a/flutter-app/pubspec.lock
+++ b/flutter-app/pubspec.lock
@@ -1325,14 +1325,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "7.0.1"
-  phosphor_flutter:
-    dependency: "direct main"
-    description:
-      name: phosphor_flutter
-      sha256: "8a14f238f28a0b54842c5a4dc20676598dd4811fcba284ed828bd5a262c11fde"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.1.0"
   pinput:
     dependency: "direct main"
     description:
diff --git a/flutter-app/pubspec.yaml b/flutter-app/pubspec.yaml
index 6a0578c3..37557582 100644
--- a/flutter-app/pubspec.yaml
+++ b/flutter-app/pubspec.yaml
@@ -100,7 +100,6 @@ dependencies:
   
   # SVG support
   flutter_svg: ^2.0.10+1
-  phosphor_flutter: ^2.1.0
   cached_network_image: ^3.4.1
   flutter_cache_manager: ^3.4.1
 
@@ -175,9 +174,6 @@ flutter:
     - assets/sounds/
     - assets/logo/
     - assets/out-app/
-    - assets/icon-library/
-    - assets/icon-library/learning-icons/
-    - assets/icon-library/button/
 
   # An image asset can refer to one or more resolution-specific "variants", see
   # https://flutter.dev/to/resolution-aware-images
diff --git a/flutter-app/test/core/l10n/i18n_assets_test.dart b/flutter-app/test/core/l10n/i18n_assets_test.dart
new file mode 100644
index 00000000..f072c071
--- /dev/null
+++ b/flutter-app/test/core/l10n/i18n_assets_test.dart
@@ -0,0 +1,57 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('i18n asset files keep matching keys and placeholders', () {
+    const locales = ['en', 'vi', 'ja', 'ko', 'zh', 'fr', 'es'];
+
+    final translations = <String, Map<String, String>>{};
+    for (final locale in locales) {
+      final file = File('assets/i18n/$locale.json');
+      expect(file.existsSync(), isTrue, reason: '$locale.json is missing');
+
+      final json = jsonDecode(file.readAsStringSync()) as Map<String, dynamic>;
+      translations[locale] = _flatten(json);
+    }
+
+    final english = translations['en']!;
+    final englishKeys = english.keys.toSet();
+    for (final entry in translations.entries) {
+      expect(
+        entry.value.keys.toSet(),
+        englishKeys,
+        reason: '${entry.key}.json must match en.json keys',
+      );
+
+      for (final key in englishKeys) {
+        expect(
+          _placeholders(entry.value[key]!),
+          _placeholders(english[key]!),
+          reason: '${entry.key}.$key placeholders must match en.$key',
+        );
+      }
+    }
+  });
+}
+
+Map<String, String> _flatten(Map<String, dynamic> json, [String prefix = '']) {
+  final result = <String, String>{};
+  for (final entry in json.entries) {
+    final key = prefix.isEmpty ? entry.key : '$prefix.${entry.key}';
+    final value = entry.value;
+    if (value is Map<String, dynamic>) {
+      result.addAll(_flatten(value, key));
+    } else {
+      result[key] = value.toString();
+    }
+  }
+  return result;
+}
+
+Set<String> _placeholders(String value) {
+  return RegExp(
+    r'\{[A-Za-z0-9_]+\}',
+  ).allMatches(value).map((match) => match.group(0)!).toSet();
+}
diff --git a/flutter-app/test/core/widgets/cefr_badge_test.dart b/flutter-app/test/core/widgets/cefr_badge_test.dart
index a8a6323f..bbcd40ff 100644
--- a/flutter-app/test/core/widgets/cefr_badge_test.dart
+++ b/flutter-app/test/core/widgets/cefr_badge_test.dart
@@ -4,10 +4,10 @@ import 'package:lexilingo_app/core/widgets/cefr_badge.dart';
 import 'package:lexilingo_app/core/theme/app_theme.dart';
 
 void main() {
-  Widget _wrap(Widget child) => MaterialApp(
-        theme: ThemeData.light(),
-        home: Scaffold(body: Center(child: child)),
-      );
+  Widget wrap(Widget child) => MaterialApp(
+    theme: ThemeData.light(),
+    home: Scaffold(body: Center(child: child)),
+  );
 
   group('CefrBadge', () {
     test('isMilestone returns true for A1/A2', () {
@@ -37,20 +37,20 @@ void main() {
     });
 
     testWidgets('renders level text', (tester) async {
-      await tester.pumpWidget(_wrap(const CefrBadge(level: 'B2')));
+      await tester.pumpWidget(wrap(const CefrBadge(level: 'B2')));
       expect(find.text('B2'), findsOneWidget);
     });
 
     testWidgets('small size renders without overflow', (tester) async {
       await tester.pumpWidget(
-        _wrap(const CefrBadge(level: 'A1', size: CefrBadgeSize.small)),
+        wrap(const CefrBadge(level: 'A1', size: CefrBadgeSize.small)),
       );
       expect(tester.takeException(), isNull);
     });
 
     testWidgets('large size renders without overflow', (tester) async {
       await tester.pumpWidget(
-        _wrap(const CefrBadge(level: 'C2', size: CefrBadgeSize.large)),
+        wrap(const CefrBadge(level: 'C2', size: CefrBadgeSize.large)),
       );
       expect(tester.takeException(), isNull);
     });
diff --git a/flutter-app/test/features/auth/data/models/user_model_test.dart b/flutter-app/test/features/auth/data/models/user_model_test.dart
index a77a29ad..8f3f0cd2 100644
--- a/flutter-app/test/features/auth/data/models/user_model_test.dart
+++ b/flutter-app/test/features/auth/data/models/user_model_test.dart
@@ -14,6 +14,7 @@ void main() {
       'is_verified': true,
       'role_slug': 'admin',
       'cefr_level': 'B1',
+      'native_language': 'ja',
       'total_xp': 500,
       'numeric_level': 3,
       'current_streak': 7,
@@ -38,6 +39,7 @@ void main() {
       expect(user.roleSlug, 'admin');
       expect(user.canAccessAdminPanel, true);
       expect(user.cefrLevel, 'B1');
+      expect(user.nativeLanguage, 'ja');
       expect(user.totalXp, 500);
       expect(user.numericLevel, 3);
       expect(user.currentStreak, 7);
@@ -55,6 +57,7 @@ void main() {
         isVerified: false,
         roleSlug: 'super_admin',
         cefrLevel: 'A1',
+        nativeLanguage: 'ko',
         totalXp: 0,
         numericLevel: 1,
         currentStreak: 0,
@@ -73,6 +76,7 @@ void main() {
       expect(json['is_verified'], false);
       expect(json['role_slug'], 'super_admin');
       expect(json['level'], 'A1');
+      expect(json['native_language'], 'ko');
       expect(json['total_xp'], 0);
       expect(json['numeric_level'], 1);
     });
@@ -118,6 +122,7 @@ void main() {
         isVerified: true,
         roleSlug: 'admin',
         cefrLevel: 'B2',
+        nativeLanguage: 'zh',
         totalXp: 1000,
         numericLevel: 4,
         currentStreak: 10,
@@ -134,6 +139,7 @@ void main() {
       expect(model.provider, 'google');
       expect(model.roleSlug, 'admin');
       expect(model.cefrLevel, 'B2');
+      expect(model.nativeLanguage, 'zh');
       expect(model.totalXp, 1000);
       expect(model.numericLevel, 4);
     });
@@ -157,6 +163,7 @@ void main() {
       expect(user.roleSlug, 'user'); // Default
       expect(user.canAccessAdminPanel, false);
       expect(user.cefrLevel, 'A1'); // Default
+      expect(user.nativeLanguage, 'vi'); // Default
       expect(user.totalXp, 0); // Default
       expect(user.numericLevel, 1); // Default
       expect(user.currentStreak, 0); // Default
diff --git a/flutter-app/test/features/chat/quick_save_chat_widgets_test.dart b/flutter-app/test/features/chat/quick_save_chat_widgets_test.dart
index 0ceb3dee..8bd54d83 100644
--- a/flutter-app/test/features/chat/quick_save_chat_widgets_test.dart
+++ b/flutter-app/test/features/chat/quick_save_chat_widgets_test.dart
@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:lexilingo_app/core/widgets/quick_save_selection_area.dart';
-import 'package:lexilingo_app/features/chat/data/models/story_model.dart';
+import 'package:lexilingo_app/features/chat/domain/entities/story.dart';
 import 'package:lexilingo_app/features/chat/presentation/pages/topic_chat_page.dart';
 import 'package:lexilingo_app/features/lexi_chat/domain/entities/lexi_message.dart';
 import 'package:lexilingo_app/features/lexi_chat/presentation/widgets/lexi_dialogue_bubble.dart';
diff --git a/flutter-app/test/features/games/presentation/helpers/game_mistake_recorder_test.dart b/flutter-app/test/features/games/presentation/helpers/game_mistake_recorder_test.dart
new file mode 100644
index 00000000..f2139b69
--- /dev/null
+++ b/flutter-app/test/features/games/presentation/helpers/game_mistake_recorder_test.dart
@@ -0,0 +1,119 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
+import 'package:lexilingo_app/features/games/presentation/helpers/game_mistake_recorder.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  group('GameMistakeRecorder', () {
+    setUp(() {
+      SharedPreferences.setMockInitialValues({});
+    });
+
+    test('records fill blank misses as grammar notebook entries', () async {
+      final repository = MistakeNotebookRepository();
+      final recorder = GameMistakeRecorder(
+        repository: repository,
+        now: () => DateTime(2026, 7, 2),
+      );
+
+      await recorder.recordFillBlankMiss(
+        question: const FillBlankQuestion(
+          id: 'fb-1',
+          sentence: 'She ___ to school every day.',
+          options: ['go', 'goes', 'went', 'gone'],
+          correctAnswer: 'goes',
+          grammarTip: 'Use third-person singular in present simple.',
+        ),
+        sessionId: 'fill-session',
+        questionIndex: 0,
+        selectedAnswer: 'go',
+      );
+
+      final entries = await repository.getEntries();
+
+      expect(entries, hasLength(1));
+      expect(entries.single.sourceType, 'game_fill_blank');
+      expect(entries.single.sourceTitle, 'Fill in the Blank');
+      expect(entries.single.question, 'She ___ to school every day.');
+      expect(entries.single.selectedAnswer, 'go');
+      expect(entries.single.correctAnswer, 'goes');
+      expect(
+        entries.single.explanation,
+        'Use third-person singular in present simple.',
+      );
+      expect(entries.single.skill, 'grammar');
+      expect(entries.single.createdAt, DateTime(2026, 7, 2));
+    });
+
+    test('records grammar quiz misses with topic metadata', () async {
+      final repository = MistakeNotebookRepository();
+      final recorder = GameMistakeRecorder(repository: repository);
+
+      await recorder.recordGrammarQuizMiss(
+        question: const GrammarQuizQuestion(
+          id: 'gq-1',
+          question: 'Choose the correct modal verb.',
+          options: ['must', 'might', 'can', 'should'],
+          correctAnswer: 'should',
+          explanation: 'Should is used for advice.',
+          topic: 'modal_verbs',
+        ),
+        sessionId: 'grammar-session',
+        questionIndex: 0,
+        selectedAnswer: 'must',
+      );
+
+      final entries = await repository.getEntries();
+
+      expect(entries.single.sourceType, 'game_grammar_quiz');
+      expect(entries.single.sourceTitle, 'Grammar Quiz - Modal Verbs');
+      expect(entries.single.skill, 'modal_verbs');
+      expect(entries.single.explanation, 'Should is used for advice.');
+    });
+
+    test(
+      'does not record correct answers and upserts repeated misses',
+      () async {
+        final repository = MistakeNotebookRepository();
+        final recorder = GameMistakeRecorder(repository: repository);
+        const question = FillBlankQuestion(
+          id: 'fb-2',
+          sentence: 'They ___ dinner now.',
+          options: ['eat', 'ate', 'are eating', 'eats'],
+          correctAnswer: 'are eating',
+        );
+
+        await recorder.recordFillBlankMiss(
+          question: question,
+          sessionId: 'session',
+          questionIndex: 0,
+          selectedAnswer: 'are eating',
+        );
+        expect(await repository.getEntries(), isEmpty);
+
+        await recorder.recordFillBlankMiss(
+          question: question,
+          sessionId: 'session',
+          questionIndex: 0,
+          selectedAnswer: 'eat',
+        );
+        await repository.markReviewed(
+          (await repository.getEntries()).single.id,
+        );
+        await recorder.recordFillBlankMiss(
+          question: question,
+          sessionId: 'session',
+          questionIndex: 0,
+          selectedAnswer: 'eat',
+        );
+
+        final entries = await repository.getEntries();
+
+        expect(entries, hasLength(1));
+        expect(entries.single.isReviewed, isFalse);
+        expect(entries.single.reviewCount, 1);
+      },
+    );
+  });
+}
diff --git a/flutter-app/test/features/games/presentation/screens/game_accessibility_test.dart b/flutter-app/test/features/games/presentation/screens/game_accessibility_test.dart
index 312c9384..0c671db6 100644
--- a/flutter-app/test/features/games/presentation/screens/game_accessibility_test.dart
+++ b/flutter-app/test/features/games/presentation/screens/game_accessibility_test.dart
@@ -8,15 +8,22 @@
 /// - GameLoadState button accessible via semantics
 library;
 
+import 'package:dartz/dartz.dart';
+import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/semantics.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/core/error/failures.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
 import 'package:lexilingo_app/features/games/data/repositories/games_repository.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/streak_entity.dart';
+import 'package:lexilingo_app/features/progress/domain/repositories/progress_repository.dart';
+import 'package:lexilingo_app/features/progress/presentation/providers/streak_provider.dart';
 import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 // ── Fakes ─────────────────────────────────────────────────────────────────────
 
@@ -27,14 +34,77 @@ class _FakeGamesRepository extends GamesRepository {
     required List<Map<String, String>> answers,
     int? clientDurationSeconds,
     int hintsUsed = 0,
-  }) async =>
-      throw UnimplementedError();
+  }) async => throw UnimplementedError();
+}
+
+class _FakeProgressRepository implements ProgressRepository {
+  @override
+  Future<Either<Failure, StreakUpdateResult>> updateStreak() async =>
+      const Right(
+        StreakUpdateResult(
+          currentStreak: 1,
+          longestStreak: 1,
+          totalDaysActive: 1,
+          freezeCount: 0,
+          streakIncreased: false,
+          streakSaved: false,
+        ),
+      );
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 // ── Helpers ───────────────────────────────────────────────────────────────────
 
+class _GameTestAssetLoader extends AssetLoader {
+  const _GameTestAssetLoader();
+
+  @override
+  Future<Map<String, dynamic>?> load(String path, Locale locale) async {
+    return const {
+      'gameResult': {
+        'xpNotAwarded': 'XP was not awarded. Your game result is preserved.',
+        'retryXp': 'Retry XP award',
+        'accuracyLabel': 'Accuracy',
+        'correctLabel': 'Correct',
+        'scoreLabel': 'Score',
+        'durationLabel': 'Duration',
+        'levelLabel': 'Level',
+        'xpEarnedLabel': 'XP Earned',
+        'totalXpLabel': 'Total XP',
+        'dailyXpLabel': 'Daily XP',
+        'streakLabel': 'Streak',
+        'streakBonusLabel': 'Streak bonus: {multiplier}x',
+        'playAgainButton': 'Play Again',
+        'backToGamesButton': 'Back to Games',
+      },
+      'games': {'retryLoad': 'Try again'},
+    };
+  }
+}
+
+Widget _localizedApp({required Widget home}) {
+  return EasyLocalization(
+    supportedLocales: const [Locale('en')],
+    path: 'assets/i18n',
+    fallbackLocale: const Locale('en'),
+    startLocale: const Locale('en'),
+    useOnlyLangCode: true,
+    assetLoader: const _GameTestAssetLoader(),
+    child: Builder(
+      builder: (context) => MaterialApp(
+        locale: context.locale,
+        supportedLocales: context.supportedLocales,
+        localizationsDelegates: context.localizationDelegates,
+        home: home,
+      ),
+    ),
+  );
+}
+
 Widget _wrapWithSize(Widget child, Size size) {
-  return MaterialApp(
+  return _localizedApp(
     home: MediaQuery(
       data: MediaQueryData(size: size),
       child: child,
@@ -43,9 +113,16 @@ Widget _wrapWithSize(Widget child, Size size) {
 }
 
 Widget _wrapWithProvider(Widget child) {
-  return MaterialApp(
-    home: ChangeNotifierProvider<GamesProvider>.value(
-      value: GamesProvider(repository: _FakeGamesRepository()),
+  return _localizedApp(
+    home: MultiProvider(
+      providers: [
+        ChangeNotifierProvider<GamesProvider>.value(
+          value: GamesProvider(repository: _FakeGamesRepository()),
+        ),
+        ChangeNotifierProvider<StreakProvider>.value(
+          value: StreakProvider(repository: _FakeProgressRepository()),
+        ),
+      ],
       child: child,
     ),
   );
@@ -73,17 +150,22 @@ GameResult _makeResult({XPAwardResult? xpResult}) => GameResult(
 // ── Tests ─────────────────────────────────────────────────────────────────────
 
 void main() {
+  setUpAll(() async {
+    TestWidgetsFlutterBinding.ensureInitialized();
+    SharedPreferences.setMockInitialValues({});
+    EasyLocalization.logger.enableLevels = [];
+    await EasyLocalization.ensureInitialized();
+  });
+
   group('GameLoadState — accessibility', () {
     testWidgets('retry button is semantically a button', (tester) async {
       await tester.pumpWidget(
         _wrapWithSize(
-          GameLoadState(
-            message: 'Could not load game.',
-            onRetry: () async {},
-          ),
+          GameLoadState(message: 'Could not load game.', onRetry: () async {}),
           const Size(390, 844),
         ),
       );
+      await tester.pumpAndSettle();
 
       final semantics = tester.getSemantics(find.byIcon(Icons.refresh_rounded));
       // The button has tap action via semantics
@@ -97,40 +179,34 @@ void main() {
     testWidgets('error icon does not block tappable controls', (tester) async {
       await tester.pumpWidget(
         _wrapWithSize(
-          GameLoadState(
-            message: 'Error.',
-            onRetry: () async {},
-          ),
+          GameLoadState(message: 'Error.', onRetry: () async {}),
           const Size(390, 844),
         ),
       );
+      await tester.pumpAndSettle();
 
       // Error icon is decorative, not tappable
       final errorIcon = find.byIcon(Icons.error_outline_rounded);
       expect(errorIcon, findsOneWidget);
     });
 
-    testWidgets('retry button has adequate minimum height (≥40px M3 standard)',
-        (tester) async {
+    testWidgets('retry button has adequate minimum height (≥40px M3 standard)', (
+      tester,
+    ) async {
       await tester.pumpWidget(
         _wrapWithSize(
-          GameLoadState(
-            message: 'Error.',
-            onRetry: () async {},
-          ),
+          GameLoadState(message: 'Error.', onRetry: () async {}),
           const Size(390, 844),
         ),
       );
+      await tester.pumpAndSettle();
 
       // FilledButton.icon uses _InputPadding which pads the hit region to 48px.
       // The render size of the visible button is 40px (Material 3 default).
       // We verify the button renders at the expected minimum logical height.
       final retryButton = find.byIcon(Icons.refresh_rounded);
       final renderBox = tester.renderObject<RenderBox>(
-        find.ancestor(
-          of: retryButton,
-          matching: find.byType(InkWell),
-        ).first,
+        find.ancestor(of: retryButton, matching: find.byType(InkWell)).first,
       );
       expect(
         renderBox.size.height,
@@ -150,9 +226,7 @@ void main() {
       final result = _makeResult(xpResult: _award);
 
       await tester.pumpWidget(
-        _wrapWithProvider(
-          GameResultScreen(result: result, xpResult: _award),
-        ),
+        _wrapWithProvider(GameResultScreen(result: result, xpResult: _award)),
       );
       await tester.pump(const Duration(milliseconds: 400));
       await tester.pump(const Duration(milliseconds: 1400));
@@ -163,14 +237,13 @@ void main() {
       expect(playAgainButtons, findsWidgets);
     });
 
-    testWidgets('cloud_off error icon has no tap action (decorative)',
-        (tester) async {
+    testWidgets('cloud_off error icon has no tap action (decorative)', (
+      tester,
+    ) async {
       final result = _makeResult(xpResult: null);
 
       await tester.pumpWidget(
-        _wrapWithProvider(
-          GameResultScreen(result: result, xpResult: null),
-        ),
+        _wrapWithProvider(GameResultScreen(result: result, xpResult: null)),
       );
       await tester.pump(const Duration(milliseconds: 400));
       await tester.pump(const Duration(milliseconds: 1400));
@@ -185,9 +258,7 @@ void main() {
       final result = _makeResult(xpResult: null);
 
       await tester.pumpWidget(
-        _wrapWithProvider(
-          GameResultScreen(result: result, xpResult: null),
-        ),
+        _wrapWithProvider(GameResultScreen(result: result, xpResult: null)),
       );
       await tester.pump(const Duration(milliseconds: 400));
       await tester.pump(const Duration(milliseconds: 1400));
@@ -211,8 +282,9 @@ void main() {
       (label: 'standard 390px', width: 390.0, height: 844.0),
       (label: 'tablet 768px', width: 768.0, height: 1024.0),
     ]) {
-      testWidgets('renders without overflow at ${testCase.label}',
-          (tester) async {
+      testWidgets('renders without overflow at ${testCase.label}', (
+        tester,
+      ) async {
         await tester.pumpWidget(
           _wrapWithSize(
             GameLoadState(
@@ -238,16 +310,26 @@ void main() {
       (label: 'standard 390px', width: 390.0, height: 844.0),
       (label: 'tablet 768px', width: 768.0, height: 1024.0),
     ]) {
-      testWidgets('renders without overflow at ${testCase.label}',
-          (tester) async {
+      testWidgets('renders without overflow at ${testCase.label}', (
+        tester,
+      ) async {
         final result = _makeResult(xpResult: _award);
 
         await tester.pumpWidget(
           MaterialApp(
             home: MediaQuery(
               data: MediaQueryData(size: Size(testCase.width, testCase.height)),
-              child: ChangeNotifierProvider<GamesProvider>.value(
-                value: GamesProvider(repository: _FakeGamesRepository()),
+              child: MultiProvider(
+                providers: [
+                  ChangeNotifierProvider<GamesProvider>.value(
+                    value: GamesProvider(repository: _FakeGamesRepository()),
+                  ),
+                  ChangeNotifierProvider<StreakProvider>.value(
+                    value: StreakProvider(
+                      repository: _FakeProgressRepository(),
+                    ),
+                  ),
+                ],
                 child: GameResultScreen(result: result, xpResult: _award),
               ),
             ),
@@ -264,8 +346,9 @@ void main() {
   });
 
   group('SpellingBee listen button — semantics', () {
-    testWidgets('listen button has a semantic label via Semantics widget',
-        (tester) async {
+    testWidgets('listen button has a semantic label via Semantics widget', (
+      tester,
+    ) async {
       // Test the Semantics wrapping we added in spelling_bee_screen.dart
       // by checking that a GestureDetector inside a Semantics(button: true)
       // is correctly labeled.
@@ -285,8 +368,9 @@ void main() {
   });
 
   group('reduced motion', () {
-    testWidgets('AnimatedContainer uses Duration.zero when disableAnimations',
-        (tester) async {
+    testWidgets('AnimatedContainer uses Duration.zero when disableAnimations', (
+      tester,
+    ) async {
       // Simulate reduced motion preference
       await tester.pumpWidget(
         MaterialApp(
diff --git a/flutter-app/test/features/games/presentation/screens/game_completion_test.dart b/flutter-app/test/features/games/presentation/screens/game_completion_test.dart
index c2c881d7..eed33814 100644
--- a/flutter-app/test/features/games/presentation/screens/game_completion_test.dart
+++ b/flutter-app/test/features/games/presentation/screens/game_completion_test.dart
@@ -9,13 +9,20 @@ library;
 
 import 'dart:async';
 
+import 'package:dartz/dartz.dart';
+import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/core/error/failures.dart';
 import 'package:lexilingo_app/features/games/data/repositories/games_repository.dart';
 import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
 import 'package:lexilingo_app/features/games/presentation/providers/games_provider.dart';
 import 'package:lexilingo_app/features/games/presentation/screens/game_result_screen.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/streak_entity.dart';
+import 'package:lexilingo_app/features/progress/domain/repositories/progress_repository.dart';
+import 'package:lexilingo_app/features/progress/presentation/providers/streak_provider.dart';
 import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 // ── Fakes ─────────────────────────────────────────────────────────────────────
 
@@ -42,6 +49,24 @@ class _FakeGamesRepository extends GamesRepository {
   }
 }
 
+class _FakeProgressRepository implements ProgressRepository {
+  @override
+  Future<Either<Failure, StreakUpdateResult>> updateStreak() async =>
+      const Right(
+        StreakUpdateResult(
+          currentStreak: 1,
+          longestStreak: 1,
+          totalDaysActive: 1,
+          freezeCount: 0,
+          streakIncreased: false,
+          streakSaved: false,
+        ),
+      );
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
 // ── Constants ─────────────────────────────────────────────────────────────────
 
 const _award = XPAwardResult(
@@ -59,10 +84,61 @@ const _answers = [
 
 // ── Helpers ───────────────────────────────────────────────────────────────────
 
+class _GameTestAssetLoader extends AssetLoader {
+  const _GameTestAssetLoader();
+
+  @override
+  Future<Map<String, dynamic>?> load(String path, Locale locale) async {
+    return const {
+      'gameResult': {
+        'xpNotAwarded': 'XP was not awarded. Your game result is preserved.',
+        'retryXp': 'Retry XP award',
+        'accuracyLabel': 'Accuracy',
+        'correctLabel': 'Correct',
+        'scoreLabel': 'Score',
+        'durationLabel': 'Duration',
+        'levelLabel': 'Level',
+        'xpEarnedLabel': 'XP Earned',
+        'totalXpLabel': 'Total XP',
+        'dailyXpLabel': 'Daily XP',
+        'streakLabel': 'Streak',
+        'streakBonusLabel': 'Streak bonus: {multiplier}x',
+        'playAgainButton': 'Play Again',
+        'backToGamesButton': 'Back to Games',
+      },
+      'games': {'retryLoad': 'Try again'},
+    };
+  }
+}
+
+Widget _localizedApp({required Widget home}) {
+  return EasyLocalization(
+    supportedLocales: const [Locale('en')],
+    path: 'assets/i18n',
+    fallbackLocale: const Locale('en'),
+    startLocale: const Locale('en'),
+    useOnlyLangCode: true,
+    assetLoader: const _GameTestAssetLoader(),
+    child: Builder(
+      builder: (context) => MaterialApp(
+        locale: context.locale,
+        supportedLocales: context.supportedLocales,
+        localizationsDelegates: context.localizationDelegates,
+        home: home,
+      ),
+    ),
+  );
+}
+
 Widget _wrap(Widget child, GamesProvider provider) {
-  return MaterialApp(
-    home: ChangeNotifierProvider<GamesProvider>.value(
-      value: provider,
+  return _localizedApp(
+    home: MultiProvider(
+      providers: [
+        ChangeNotifierProvider<GamesProvider>.value(value: provider),
+        ChangeNotifierProvider<StreakProvider>(
+          create: (_) => StreakProvider(repository: _FakeProgressRepository()),
+        ),
+      ],
       child: child,
     ),
   );
@@ -90,8 +166,11 @@ Future<void> _drainTimers(WidgetTester tester) async {
 // ── Widget Tests ──────────────────────────────────────────────────────────────
 
 void main() {
-  setUpAll(() {
+  setUpAll(() async {
     TestWidgetsFlutterBinding.ensureInitialized();
+    SharedPreferences.setMockInitialValues({});
+    EasyLocalization.logger.enableLevels = [];
+    await EasyLocalization.ensureInitialized();
   });
 
   group('GameResultScreen — award succeeded', () {
@@ -112,8 +191,9 @@ void main() {
       expect(find.byIcon(Icons.cloud_off_rounded), findsNothing);
     });
 
-    testWidgets('does not show error card when xpResult is present',
-        (tester) async {
+    testWidgets('does not show error card when xpResult is present', (
+      tester,
+    ) async {
       final result = _makeResult(xpResult: _award);
 
       await tester.pumpWidget(
@@ -129,8 +209,9 @@ void main() {
   });
 
   group('GameResultScreen — award failed', () {
-    testWidgets('shows error card with cloud_off icon when xpResult is null',
-        (tester) async {
+    testWidgets('shows error card with cloud_off icon when xpResult is null', (
+      tester,
+    ) async {
       final result = _makeResult(xpResult: null);
 
       await tester.pumpWidget(
@@ -144,8 +225,9 @@ void main() {
       expect(find.byIcon(Icons.cloud_off_rounded), findsOneWidget);
     });
 
-    testWidgets('retry button (refresh icon) is visible in error state',
-        (tester) async {
+    testWidgets('retry button (refresh icon) is visible in error state', (
+      tester,
+    ) async {
       final result = _makeResult(xpResult: null);
 
       await tester.pumpWidget(
@@ -160,8 +242,9 @@ void main() {
       expect(find.byIcon(Icons.refresh_rounded), findsAtLeastNWidgets(1));
     });
 
-    testWidgets('tapping retry triggers second completion and awards XP',
-        (tester) async {
+    testWidgets('tapping retry triggers second completion and awards XP', (
+      tester,
+    ) async {
       final repo = _FakeGamesRepository(
         outcomes: [Exception('network error'), _award],
       );
@@ -203,47 +286,45 @@ void main() {
 
   group('GameResultScreen — already awarded', () {
     testWidgets(
-        'result screen renders without resubmitting when already awarded',
-        (tester) async {
-      final repository = _FakeGamesRepository(outcomes: [_award]);
-      final provider = GamesProvider(repository: repository);
-
-      // Award once
-      await provider.completeGame(
-        gameType: GameType.wordScramble,
-        score: 10,
-        totalQuestions: 10,
-        correctAnswers: 10,
-        answers: _answers,
-        sessionId: 'session-z',
-      );
-      // Try to award again — should hit alreadyAwarded path
-      await provider.completeGame(
-        gameType: GameType.wordScramble,
-        score: 10,
-        totalQuestions: 10,
-        correctAnswers: 10,
-        answers: _answers,
-        sessionId: 'session-z',
-      );
-      expect(provider.awardStatus, GameAwardStatus.alreadyAwarded);
-      expect(repository.completionCalls, 1);
-
-      final result = _makeResult(xpResult: _award);
-
-      await tester.pumpWidget(
-        _wrap(
-          GameResultScreen(result: result, xpResult: _award),
-          provider,
-        ),
-      );
-      await _drainTimers(tester);
-
-      // Still only one network call
-      expect(repository.completionCalls, 1);
-      // Result screen shows correctly (no error state)
-      expect(find.byIcon(Icons.cloud_off_rounded), findsNothing);
-    });
+      'result screen renders without resubmitting when already awarded',
+      (tester) async {
+        final repository = _FakeGamesRepository(outcomes: [_award]);
+        final provider = GamesProvider(repository: repository);
+
+        // Award once
+        await provider.completeGame(
+          gameType: GameType.wordScramble,
+          score: 10,
+          totalQuestions: 10,
+          correctAnswers: 10,
+          answers: _answers,
+          sessionId: 'session-z',
+        );
+        // Try to award again — should hit alreadyAwarded path
+        await provider.completeGame(
+          gameType: GameType.wordScramble,
+          score: 10,
+          totalQuestions: 10,
+          correctAnswers: 10,
+          answers: _answers,
+          sessionId: 'session-z',
+        );
+        expect(provider.awardStatus, GameAwardStatus.alreadyAwarded);
+        expect(repository.completionCalls, 1);
+
+        final result = _makeResult(xpResult: _award);
+
+        await tester.pumpWidget(
+          _wrap(GameResultScreen(result: result, xpResult: _award), provider),
+        );
+        await _drainTimers(tester);
+
+        // Still only one network call
+        expect(repository.completionCalls, 1);
+        // Result screen shows correctly (no error state)
+        expect(find.byIcon(Icons.cloud_off_rounded), findsNothing);
+      },
+    );
   });
 
   // ── Unit tests for provider answer payloads ────────────────────────────────
@@ -299,7 +380,9 @@ void main() {
         score: 10,
         totalQuestions: 1,
         correctAnswers: 1,
-        answers: [{'id': 'h1', 'answer': 'elephant'}],
+        answers: [
+          {'id': 'h1', 'answer': 'elephant'},
+        ],
         sessionId: 'hangman-session-1',
         hintsUsed: 2,
       );
diff --git a/flutter-app/test/features/games/presentation/screens/game_load_state_test.dart b/flutter-app/test/features/games/presentation/screens/game_load_state_test.dart
index 601c1267..734f0273 100644
--- a/flutter-app/test/features/games/presentation/screens/game_load_state_test.dart
+++ b/flutter-app/test/features/games/presentation/screens/game_load_state_test.dart
@@ -10,26 +10,63 @@ library;
 
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:easy_localization/easy_localization.dart';
 import 'package:lexilingo_app/features/games/presentation/widgets/game_load_state.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 // ── Helpers ───────────────────────────────────────────────────────────────────
 
+class _GameTestAssetLoader extends AssetLoader {
+  const _GameTestAssetLoader();
+
+  @override
+  Future<Map<String, dynamic>> load(String path, Locale locale) async {
+    return {
+      'games': {'retryLoad': 'Try again'},
+    };
+  }
+}
+
 Widget _wrap(Widget child) {
-  return MaterialApp(home: child);
+  return EasyLocalization(
+    supportedLocales: const [Locale('en')],
+    path: 'assets/i18n',
+    fallbackLocale: const Locale('en'),
+    startLocale: const Locale('en'),
+    useOnlyLangCode: true,
+    assetLoader: const _GameTestAssetLoader(),
+    child: Builder(
+      builder: (context) => MaterialApp(
+        locale: context.locale,
+        supportedLocales: context.supportedLocales,
+        localizationsDelegates: context.localizationDelegates,
+        home: child,
+      ),
+    ),
+  );
+}
+
+Future<void> _pumpWrapped(WidgetTester tester, Widget child) async {
+  await tester.pumpWidget(_wrap(child));
+  await tester.pump();
+  await tester.pump(const Duration(milliseconds: 1));
 }
 
 // ── Tests ─────────────────────────────────────────────────────────────────────
 
 void main() {
+  setUpAll(() async {
+    TestWidgetsFlutterBinding.ensureInitialized();
+    SharedPreferences.setMockInitialValues({});
+    EasyLocalization.logger.enableLevels = [];
+    await EasyLocalization.ensureInitialized();
+  });
+
   group('GameLoadState', () {
     testWidgets('shows error_outline icon', (tester) async {
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Network error occurred.',
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: 'Network error occurred.', onRetry: () async {}),
       );
 
       expect(find.byIcon(Icons.error_outline_rounded), findsOneWidget);
@@ -37,23 +74,18 @@ void main() {
 
     testWidgets('displays the provided message text', (tester) async {
       const msg = 'Unable to load this game.';
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(message: msg, onRetry: () async {}),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: msg, onRetry: () async {}),
       );
 
       expect(find.text(msg), findsOneWidget);
     });
 
     testWidgets('shows a retry button with refresh icon', (tester) async {
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Failed to load.',
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: 'Failed to load.', onRetry: () async {}),
       );
 
       // Retry button identified by its refresh icon
@@ -63,13 +95,9 @@ void main() {
     testWidgets('retry callback is invoked on button tap', (tester) async {
       int retryCount = 0;
 
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Error.',
-            onRetry: () async => retryCount++,
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: 'Error.', onRetry: () async => retryCount++),
       );
 
       await tester.tap(find.byIcon(Icons.refresh_rounded));
@@ -81,13 +109,9 @@ void main() {
     testWidgets('retry callback can be called multiple times', (tester) async {
       int retryCount = 0;
 
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Error.',
-            onRetry: () async => retryCount++,
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: 'Error.', onRetry: () async => retryCount++),
       );
 
       await tester.tap(find.byIcon(Icons.refresh_rounded));
@@ -100,13 +124,9 @@ void main() {
 
     testWidgets('renders with network error message', (tester) async {
       const networkMessage = 'Unable to load this game. Please try again.';
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: networkMessage,
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: networkMessage, onRetry: () async {}),
       );
 
       expect(find.text(networkMessage), findsOneWidget);
@@ -115,13 +135,9 @@ void main() {
 
     testWidgets('renders with empty payload message', (tester) async {
       const emptyMessage = 'This game has no playable content right now.';
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: emptyMessage,
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: emptyMessage, onRetry: () async {}),
       );
 
       expect(find.text(emptyMessage), findsOneWidget);
@@ -130,26 +146,18 @@ void main() {
 
     testWidgets('renders with malformed payload message', (tester) async {
       const malformedMessage = 'Unexpected game data received.';
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: malformedMessage,
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: malformedMessage, onRetry: () async {}),
       );
 
       expect(find.text(malformedMessage), findsOneWidget);
     });
 
     testWidgets('layout is constrained to maxWidth 360', (tester) async {
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Error.',
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: 'Error.', onRetry: () async {}),
       );
 
       // Find the ConstrainedBox with the 360 max width
@@ -158,66 +166,54 @@ void main() {
       );
       final maxWidthBox = constrainedBoxes.firstWhere(
         (cb) => cb.constraints.maxWidth == 360,
-        orElse: () => throw TestFailure(
-          'No ConstrainedBox with maxWidth 360 found',
-        ),
+        orElse: () =>
+            throw TestFailure('No ConstrainedBox with maxWidth 360 found'),
       );
       expect(maxWidthBox.constraints.maxWidth, 360);
     });
 
-    testWidgets('stale error from one game does not leak to next game state',
-        (tester) async {
+    testWidgets('stale error from one game does not leak to next game state', (
+      tester,
+    ) async {
       // Simulate showing error for game A
       const errorMsgA = 'Word Scramble failed to load.';
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: errorMsgA,
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: errorMsgA, onRetry: () async {}),
       );
       expect(find.text(errorMsgA), findsOneWidget);
 
       // Swap to loading state (game B starts loading)
-      await tester.pumpWidget(
-        _wrap(
-          const Scaffold(
-            body: Center(child: CircularProgressIndicator()),
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        const Scaffold(body: Center(child: CircularProgressIndicator())),
       );
-      await tester.pump();
 
       // Error A message must not be in the tree
       expect(find.text(errorMsgA), findsNothing);
 
       // Show error for game B — independent message
       const errorMsgB = 'Hangman failed to load.';
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: errorMsgB,
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: errorMsgB, onRetry: () async {}),
       );
       expect(find.text(errorMsgB), findsOneWidget);
       expect(find.text(errorMsgA), findsNothing);
     });
 
-    testWidgets('retry callback triggers reload and clears error state',
-        (tester) async {
+    testWidgets('retry callback triggers reload and clears error state', (
+      tester,
+    ) async {
       bool reloaded = false;
 
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Game failed to load.',
-            onRetry: () async {
-              reloaded = true;
-            },
-          ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(
+          message: 'Game failed to load.',
+          onRetry: () async {
+            reloaded = true;
+          },
         ),
       );
 
@@ -229,42 +225,33 @@ void main() {
   });
 
   group('GameLoadState — loading state (Scaffold + indicator)', () {
-    testWidgets('loading indicator is visible when isLoading is true',
-        (tester) async {
+    testWidgets('loading indicator is visible when isLoading is true', (
+      tester,
+    ) async {
       // Simulate loading state with a progress indicator (as used in game screens)
-      await tester.pumpWidget(
-        _wrap(
-          const Scaffold(
-            body: Center(child: CircularProgressIndicator()),
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        const Scaffold(body: Center(child: CircularProgressIndicator())),
       );
-      await tester.pump();
 
       expect(find.byType(CircularProgressIndicator), findsOneWidget);
     });
 
-    testWidgets('GameLoadState replaces loading indicator on error', (tester) async {
+    testWidgets('GameLoadState replaces loading indicator on error', (
+      tester,
+    ) async {
       // Loading state
-      await tester.pumpWidget(
-        _wrap(
-          const Scaffold(
-            body: Center(child: CircularProgressIndicator()),
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        const Scaffold(body: Center(child: CircularProgressIndicator())),
       );
       expect(find.byType(CircularProgressIndicator), findsOneWidget);
 
       // Error state replaces it
-      await tester.pumpWidget(
-        _wrap(
-          GameLoadState(
-            message: 'Failed to load.',
-            onRetry: () async {},
-          ),
-        ),
+      await _pumpWrapped(
+        tester,
+        GameLoadState(message: 'Failed to load.', onRetry: () async {}),
       );
-      await tester.pump();
 
       expect(find.byType(CircularProgressIndicator), findsNothing);
       expect(find.byIcon(Icons.error_outline_rounded), findsOneWidget);
diff --git a/flutter-app/test/features/games/presentation/widgets/daily_challenge_mapper_test.dart b/flutter-app/test/features/games/presentation/widgets/daily_challenge_mapper_test.dart
new file mode 100644
index 00000000..3fc1f491
--- /dev/null
+++ b/flutter-app/test/features/games/presentation/widgets/daily_challenge_mapper_test.dart
@@ -0,0 +1,60 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/games/domain/entities/game_entities.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/daily_challenge_mapper.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/daily_challenge_entity.dart';
+
+DailyChallengeEntity _challenge({
+  String title = 'Practice words',
+  String description = 'Complete a vocabulary word challenge',
+  String category = 'vocabulary',
+  int xpReward = 30,
+  bool isCompleted = false,
+}) {
+  return DailyChallengeEntity(
+    id: 'daily-1',
+    title: title,
+    description: description,
+    icon: 'word',
+    category: category,
+    target: 5,
+    current: isCompleted ? 5 : 2,
+    xpReward: xpReward,
+    isCompleted: isCompleted,
+    expiresAt: DateTime(2026, 7, 2),
+  );
+}
+
+void main() {
+  test('maps vocabulary daily challenge to word scramble', () {
+    final challenge = _challenge();
+
+    expect(gameTypeForDailyChallenge(challenge), GameType.wordScramble);
+    expect(
+      toGameDailyChallenge(challenge).gameType,
+      GameType.wordScramble.apiKey,
+    );
+  });
+
+  test('maps grammar daily challenge to grammar quiz', () {
+    final challenge = _challenge(
+      title: 'Grammar sprint',
+      description: 'Answer 5 grammar questions',
+      category: 'lesson',
+    );
+
+    expect(gameTypeForDailyChallenge(challenge), GameType.grammarQuiz);
+  });
+
+  test(
+    'preserves completion and raises bonus multiplier for larger rewards',
+    () {
+      final mapped = toGameDailyChallenge(
+        _challenge(xpReward: 50, isCompleted: true),
+      );
+
+      expect(mapped.completed, isTrue);
+      expect(mapped.bonusMultiplier, 2);
+      expect(mapped.targetScore, 5);
+    },
+  );
+}
diff --git a/flutter-app/test/features/games/presentation/widgets/game_powerup_tray_test.dart b/flutter-app/test/features/games/presentation/widgets/game_powerup_tray_test.dart
new file mode 100644
index 00000000..f7d7d876
--- /dev/null
+++ b/flutter-app/test/features/games/presentation/widgets/game_powerup_tray_test.dart
@@ -0,0 +1,270 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:provider/provider.dart';
+import 'package:lexilingo_app/features/games/presentation/widgets/game_powerup_tray.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/inventory_item.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/leaderboard_entry.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/starter_reward.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/wallet.dart';
+import 'package:lexilingo_app/features/gamification/domain/repositories/gamification_repository.dart';
+import 'package:lexilingo_app/features/gamification/presentation/providers/gamification_provider.dart';
+
+class _FakeRepository implements GamificationRepository {
+  _FakeRepository({this.items = const [], this.useItemEffects});
+
+  final List<InventoryItemEntity> items;
+  final Map<String, dynamic>? useItemEffects;
+  String? lastUsedInventoryId;
+
+  @override
+  Future<List<InventoryItemEntity>> getInventory() async => items;
+
+  @override
+  Future<Map<String, dynamic>?> useItem(String inventoryId) async {
+    lastUsedInventoryId = inventoryId;
+    return useItemEffects;
+  }
+
+  @override
+  Future<WalletEntity> getWallet() async => throw UnimplementedError();
+  @override
+  Future<List<WalletTransactionEntity>> getTransactions({
+    int limit = 50,
+  }) async => [];
+  @override
+  Future<StarterRewardEntity?> getPendingStarterReward() async => null;
+  @override
+  Future<bool> acknowledgeStarterReward() async => false;
+  @override
+  Future<List<ShopItemEntity>> getShopItems() async => [];
+  @override
+  Future<bool> purchaseItem(String itemId, {int quantity = 1}) async => false;
+  @override
+  Future<String?> equipAvatar(String inventoryId) async => null;
+  @override
+  Future<LeaderboardEntity> getLeaderboard(String league) async =>
+      throw UnimplementedError();
+  @override
+  Future<LeagueStatusEntity> getLeagueStatus() async =>
+      throw UnimplementedError();
+}
+
+InventoryItemEntity _powerUpItem({
+  required String id,
+  required String itemType,
+  required int quantity,
+}) => InventoryItemEntity.fromJson({
+  'id': id,
+  'item': {
+    'id': 'item_$id',
+    'name': 'Test Power-Up',
+    'description': 'desc',
+    'category': 'power_ups',
+    'price_gems': 10,
+    'icon_url': '',
+    'effect_type': itemType,
+    'effects': {'seconds': 10},
+    'is_available': true,
+  },
+  'quantity': quantity,
+  'is_active': false,
+  'purchased_at': DateTime.now().toIso8601String(),
+});
+
+Widget _wrap(GamificationProvider provider, Widget child) =>
+    MaterialApp(
+      home: ChangeNotifierProvider<GamificationProvider>.value(
+        value: provider,
+        child: Scaffold(body: child),
+      ),
+    );
+
+void main() {
+  testWidgets('renders nothing when no power-ups are owned', (tester) async {
+    final provider = GamificationProvider(repository: _FakeRepository());
+    await provider.loadInventory();
+
+    await tester.pumpWidget(
+      _wrap(
+        provider,
+        GamePowerUpTray(
+          availableTypes: const [ShopItemEntity.effectTimeFreeze],
+          onUse: (_, __) {},
+        ),
+      ),
+    );
+
+    expect(find.byType(SizedBox), findsWidgets);
+    expect(find.text('1'), findsNothing);
+  });
+
+  testWidgets('shows the owned quantity badge for an available power-up', (
+    tester,
+  ) async {
+    final provider = GamificationProvider(
+      repository: _FakeRepository(
+        items: [
+          _powerUpItem(
+            id: 'a',
+            itemType: ShopItemEntity.effectTimeFreeze,
+            quantity: 3,
+          ),
+        ],
+      ),
+    );
+    await provider.loadInventory();
+
+    await tester.pumpWidget(
+      _wrap(
+        provider,
+        GamePowerUpTray(
+          availableTypes: const [ShopItemEntity.effectTimeFreeze],
+          onUse: (_, __) {},
+        ),
+      ),
+    );
+    await tester.pump();
+
+    expect(find.text('3'), findsOneWidget);
+  });
+
+  testWidgets('omits power-up types that are owned but not in availableTypes', (
+    tester,
+  ) async {
+    final provider = GamificationProvider(
+      repository: _FakeRepository(
+        items: [
+          _powerUpItem(
+            id: 'a',
+            itemType: ShopItemEntity.effectSkipToken,
+            quantity: 1,
+          ),
+        ],
+      ),
+    );
+    await provider.loadInventory();
+
+    await tester.pumpWidget(
+      _wrap(
+        provider,
+        GamePowerUpTray(
+          availableTypes: const [ShopItemEntity.effectTimeFreeze],
+          onUse: (_, __) {},
+        ),
+      ),
+    );
+    await tester.pump();
+
+    expect(find.text('1'), findsNothing);
+  });
+
+  testWidgets('tapping a power-up calls onUse with the effects payload', (
+    tester,
+  ) async {
+    final repository = _FakeRepository(
+      items: [
+        _powerUpItem(
+          id: 'a',
+          itemType: ShopItemEntity.effectTimeFreeze,
+          quantity: 1,
+        ),
+      ],
+      useItemEffects: {'seconds': 10, 'item_type': 'time_freeze'},
+    );
+    final provider = GamificationProvider(repository: repository);
+    await provider.loadInventory();
+
+    String? usedType;
+    Map<String, dynamic>? usedEffects;
+
+    await tester.pumpWidget(
+      _wrap(
+        provider,
+        GamePowerUpTray(
+          availableTypes: const [ShopItemEntity.effectTimeFreeze],
+          onUse: (type, effects) {
+            usedType = type;
+            usedEffects = effects;
+          },
+        ),
+      ),
+    );
+    await tester.pump();
+
+    await tester.tap(find.byType(GestureDetector).first);
+    await tester.pumpAndSettle();
+
+    expect(repository.lastUsedInventoryId, 'a');
+    expect(usedType, ShopItemEntity.effectTimeFreeze);
+    expect(usedEffects?['seconds'], 10);
+  });
+
+  testWidgets('tapping does not invoke onUse when the repository fails', (
+    tester,
+  ) async {
+    final provider = GamificationProvider(
+      repository: _FakeRepository(
+        items: [
+          _powerUpItem(
+            id: 'a',
+            itemType: ShopItemEntity.effectTimeFreeze,
+            quantity: 1,
+          ),
+        ],
+        useItemEffects: null,
+      ),
+    );
+    await provider.loadInventory();
+
+    var called = false;
+
+    await tester.pumpWidget(
+      _wrap(
+        provider,
+        GamePowerUpTray(
+          availableTypes: const [ShopItemEntity.effectTimeFreeze],
+          onUse: (_, __) => called = true,
+        ),
+      ),
+    );
+    await tester.pump();
+
+    await tester.tap(find.byType(GestureDetector).first);
+    await tester.pumpAndSettle();
+
+    expect(called, isFalse);
+  });
+
+  testWidgets('disables tapping when enabled is false', (tester) async {
+    final repository = _FakeRepository(
+      items: [
+        _powerUpItem(
+          id: 'a',
+          itemType: ShopItemEntity.effectTimeFreeze,
+          quantity: 1,
+        ),
+      ],
+      useItemEffects: {'seconds': 10},
+    );
+    final provider = GamificationProvider(repository: repository);
+    await provider.loadInventory();
+
+    await tester.pumpWidget(
+      _wrap(
+        provider,
+        GamePowerUpTray(
+          availableTypes: const [ShopItemEntity.effectTimeFreeze],
+          onUse: (_, __) {},
+          enabled: false,
+        ),
+      ),
+    );
+    await tester.pump();
+
+    await tester.tap(find.byType(GestureDetector).first);
+    await tester.pumpAndSettle();
+
+    expect(repository.lastUsedInventoryId, isNull);
+  });
+}
diff --git a/flutter-app/test/features/gamification/gamification_provider_active_boosts_test.dart b/flutter-app/test/features/gamification/gamification_provider_active_boosts_test.dart
index b5cce347..ee060965 100644
--- a/flutter-app/test/features/gamification/gamification_provider_active_boosts_test.dart
+++ b/flutter-app/test/features/gamification/gamification_provider_active_boosts_test.dart
@@ -28,7 +28,7 @@ class _FakeRepository implements GamificationRepository {
   @override
   Future<bool> purchaseItem(String itemId, {int quantity = 1}) async => false;
   @override
-  Future<bool> useItem(String inventoryId) async => false;
+  Future<Map<String, dynamic>?> useItem(String inventoryId) async => null;
   @override
   Future<String?> equipAvatar(String inventoryId) async => null;
   @override
diff --git a/flutter-app/test/features/gamification/gamification_provider_powerups_test.dart b/flutter-app/test/features/gamification/gamification_provider_powerups_test.dart
new file mode 100644
index 00000000..e44648d8
--- /dev/null
+++ b/flutter-app/test/features/gamification/gamification_provider_powerups_test.dart
@@ -0,0 +1,167 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/inventory_item.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/leaderboard_entry.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/shop_item.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/starter_reward.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/wallet.dart';
+import 'package:lexilingo_app/features/gamification/domain/repositories/gamification_repository.dart';
+import 'package:lexilingo_app/features/gamification/presentation/providers/gamification_provider.dart';
+
+class _FakeRepository implements GamificationRepository {
+  _FakeRepository({required this.items, this.useItemEffects});
+
+  final List<InventoryItemEntity> items;
+
+  /// When set, `useItem` returns this payload and succeeds; null = failure.
+  final Map<String, dynamic>? useItemEffects;
+  String? lastUsedInventoryId;
+
+  @override
+  Future<List<InventoryItemEntity>> getInventory() async => items;
+
+  @override
+  Future<Map<String, dynamic>?> useItem(String inventoryId) async {
+    lastUsedInventoryId = inventoryId;
+    return useItemEffects;
+  }
+
+  @override
+  Future<WalletEntity> getWallet() async => throw UnimplementedError();
+  @override
+  Future<List<WalletTransactionEntity>> getTransactions({
+    int limit = 50,
+  }) async => [];
+  @override
+  Future<StarterRewardEntity?> getPendingStarterReward() async => null;
+  @override
+  Future<bool> acknowledgeStarterReward() async => false;
+  @override
+  Future<List<ShopItemEntity>> getShopItems() async => [];
+  @override
+  Future<bool> purchaseItem(String itemId, {int quantity = 1}) async => false;
+  @override
+  Future<String?> equipAvatar(String inventoryId) async => null;
+  @override
+  Future<LeaderboardEntity> getLeaderboard(String league) async =>
+      throw UnimplementedError();
+  @override
+  Future<LeagueStatusEntity> getLeagueStatus() async =>
+      throw UnimplementedError();
+}
+
+InventoryItemEntity _powerUpItem({
+  required String id,
+  required String itemType,
+  required int quantity,
+}) => InventoryItemEntity.fromJson({
+  'id': id,
+  'item': {
+    'id': 'item_$id',
+    'name': 'Test Power-Up',
+    'description': 'desc',
+    'category': 'power_ups',
+    'price_gems': 10,
+    'icon_url': '',
+    'effect_type': itemType,
+    'effects': {'seconds': 10},
+    'is_available': true,
+  },
+  'quantity': quantity,
+  'is_active': false,
+  'purchased_at': DateTime.now().toIso8601String(),
+});
+
+void main() {
+  group('GamificationProvider.powerUpsOf', () {
+    test('returns only owned items matching the requested item type', () async {
+      final provider = GamificationProvider(
+        repository: _FakeRepository(
+          items: [
+            _powerUpItem(
+              id: 'a',
+              itemType: ShopItemEntity.effectTimeFreeze,
+              quantity: 2,
+            ),
+            _powerUpItem(
+              id: 'b',
+              itemType: ShopItemEntity.effectSkipToken,
+              quantity: 1,
+            ),
+          ],
+        ),
+      );
+
+      await provider.loadInventory();
+      final timeFreezes = provider.powerUpsOf(ShopItemEntity.effectTimeFreeze);
+      expect(timeFreezes.length, 1);
+      expect(timeFreezes.first.id, 'a');
+      provider.dispose();
+    });
+
+    test('excludes owned items with zero quantity', () async {
+      final provider = GamificationProvider(
+        repository: _FakeRepository(
+          items: [
+            _powerUpItem(
+              id: 'a',
+              itemType: ShopItemEntity.effectMistakeShield,
+              quantity: 0,
+            ),
+          ],
+        ),
+      );
+
+      await provider.loadInventory();
+      expect(provider.powerUpsOf(ShopItemEntity.effectMistakeShield), isEmpty);
+      provider.dispose();
+    });
+  });
+
+  group('GamificationProvider.useItemWithEffects', () {
+    test('returns the effects payload and refreshes inventory on success', () async {
+      final repository = _FakeRepository(
+        items: [
+          _powerUpItem(
+            id: 'a',
+            itemType: ShopItemEntity.effectTimeFreeze,
+            quantity: 1,
+          ),
+        ],
+        useItemEffects: {'seconds': 10, 'item_type': 'time_freeze'},
+      );
+      final provider = GamificationProvider(repository: repository);
+
+      await provider.loadInventory();
+      final effects = await provider.useItemWithEffects('a');
+
+      expect(effects, isNotNull);
+      expect(effects!['seconds'], 10);
+      expect(repository.lastUsedInventoryId, 'a');
+      provider.dispose();
+    });
+
+    test('returns null when the repository reports failure', () async {
+      final provider = GamificationProvider(
+        repository: _FakeRepository(items: [], useItemEffects: null),
+      );
+
+      final effects = await provider.useItemWithEffects('missing');
+      expect(effects, isNull);
+      provider.dispose();
+    });
+
+    test('useItem (legacy bool API) reflects success/failure of the new path', () async {
+      final successProvider = GamificationProvider(
+        repository: _FakeRepository(items: [], useItemEffects: {}),
+      );
+      expect(await successProvider.useItem('a'), isTrue);
+      successProvider.dispose();
+
+      final failureProvider = GamificationProvider(
+        repository: _FakeRepository(items: [], useItemEffects: null),
+      );
+      expect(await failureProvider.useItem('a'), isFalse);
+      failureProvider.dispose();
+    });
+  });
+}
diff --git a/flutter-app/test/features/gamification/gamification_provider_starter_reward_test.dart b/flutter-app/test/features/gamification/gamification_provider_starter_reward_test.dart
index 846e8edb..d41ce377 100644
--- a/flutter-app/test/features/gamification/gamification_provider_starter_reward_test.dart
+++ b/flutter-app/test/features/gamification/gamification_provider_starter_reward_test.dart
@@ -33,7 +33,7 @@ class _FakeRepository implements GamificationRepository {
   @override
   Future<List<InventoryItemEntity>> getInventory() async => [];
   @override
-  Future<bool> useItem(String inventoryId) async => false;
+  Future<Map<String, dynamic>?> useItem(String inventoryId) async => null;
   @override
   Future<String?> equipAvatar(String inventoryId) async => null;
   @override
diff --git a/flutter-app/test/features/gamification/shop_item_test.dart b/flutter-app/test/features/gamification/shop_item_test.dart
index f56aa401..7e8d73c8 100644
--- a/flutter-app/test/features/gamification/shop_item_test.dart
+++ b/flutter-app/test/features/gamification/shop_item_test.dart
@@ -46,4 +46,22 @@ void main() {
       expect(item.category, ShopItemEntity.categoryPowerUps);
     }
   });
+
+  test('maps all in-game power-up item types into power ups category', () {
+    for (final type in ShopItemEntity.gamePowerUpEffectTypes) {
+      final item = ShopItemEntity.fromJson({
+        'id': type,
+        'name': type,
+        'description': type,
+        'item_type': type,
+        'price_gems': 15,
+      });
+      expect(
+        item.category,
+        ShopItemEntity.categoryPowerUps,
+        reason: '$type should map to categoryPowerUps',
+      );
+      expect(item.effectType, type);
+    }
+  });
 }
diff --git a/flutter-app/test/features/gamification/wallet_entity_test.dart b/flutter-app/test/features/gamification/wallet_entity_test.dart
new file mode 100644
index 00000000..57e4e381
--- /dev/null
+++ b/flutter-app/test/features/gamification/wallet_entity_test.dart
@@ -0,0 +1,34 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/gamification/domain/entities/wallet.dart';
+
+void main() {
+  test('wallet maps backend gem totals and updated timestamp', () {
+    final wallet = WalletEntity.fromJson({
+      'id': 'wallet-1',
+      'user_id': 'user-1',
+      'gems': 75,
+      'total_gems_earned': 125,
+      'total_gems_spent': 50,
+      'updated_at': '2026-06-06T00:00:00Z',
+    });
+
+    expect(wallet.userId, 'user-1');
+    expect(wallet.gems, 75);
+    expect(wallet.totalEarned, 125);
+    expect(wallet.totalSpent, 50);
+    expect(wallet.lastUpdated, DateTime.parse('2026-06-06T00:00:00Z'));
+  });
+
+  test('wallet transaction maps backend transaction_type', () {
+    final transaction = WalletTransactionEntity.fromJson({
+      'id': 'tx-1',
+      'transaction_type': 'spend',
+      'amount': -20,
+      'description': 'Purchased avatar',
+      'created_at': '2026-06-06T00:00:00Z',
+    });
+
+    expect(transaction.type, 'spend');
+    expect(transaction.isSpending, isTrue);
+  });
+}
diff --git a/flutter-app/test/features/home/today_plan_models_test.dart b/flutter-app/test/features/home/today_plan_models_test.dart
new file mode 100644
index 00000000..40e90bc6
--- /dev/null
+++ b/flutter-app/test/features/home/today_plan_models_test.dart
@@ -0,0 +1,115 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/course/domain/entities/course_entity.dart';
+import 'package:lexilingo_app/features/home/presentation/widgets/home_page/today_plan_models.dart';
+import 'package:lexilingo_app/features/level/domain/entities/proficiency_entity.dart';
+import 'package:lexilingo_app/features/progress/domain/entities/daily_challenge_entity.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  setUpAll(() async {
+    SharedPreferences.setMockInitialValues({});
+    EasyLocalization.logger.enableLevels = [];
+    await EasyLocalization.ensureInitialized();
+  });
+
+  group('buildTodayPlanSnapshot', () {
+    test('builds the default daily learning sequence from available data', () {
+      final snapshot = buildTodayPlanSnapshot(
+        dueVocabularyCount: 4,
+        enrolledCourses: [_course(progress: 0.35)],
+        weakestSkills: [_skill(SkillType.listening, score: 42)],
+        challenges: [_challenge(category: 'vocabulary', current: 1, target: 3)],
+      );
+
+      expect(snapshot.totalCount, 5);
+      expect(snapshot.tasks.map((task) => task.type), [
+        TodayPlanTaskType.vocabulary,
+        TodayPlanTaskType.course,
+        TodayPlanTaskType.skill,
+        TodayPlanTaskType.challenge,
+        TodayPlanTaskType.conversation,
+      ]);
+      expect(
+        snapshot.tasks[0].destination,
+        TodayPlanDestination.vocabularyReview,
+      );
+      expect(snapshot.tasks[2].destination, TodayPlanDestination.podcast);
+      expect(
+        snapshot.tasks[3].destination,
+        TodayPlanDestination.vocabularyReview,
+      );
+      expect(snapshot.completedCount, 0);
+    });
+
+    test('falls back to starter tasks when learner data is empty', () {
+      final snapshot = buildTodayPlanSnapshot(
+        dueVocabularyCount: 0,
+        enrolledCourses: const [],
+        weakestSkills: const [],
+        challenges: const [],
+      );
+
+      expect(snapshot.totalCount, 5);
+      expect(snapshot.tasks[0].isCompleted, isTrue);
+      expect(snapshot.tasks[1].destination, TodayPlanDestination.courseList);
+      expect(snapshot.tasks[2].destination, TodayPlanDestination.voice);
+      expect(snapshot.tasks[3].destination, TodayPlanDestination.games);
+      expect(snapshot.tasks[4].destination, TodayPlanDestination.lexi);
+      expect(snapshot.nextTask, snapshot.tasks[1]);
+    });
+  });
+}
+
+CourseEntity _course({required double progress}) {
+  final now = DateTime(2026, 6, 30);
+  return CourseEntity(
+    id: 'course-1',
+    title: 'A2 Daily English',
+    description: 'Everyday English practice',
+    language: 'en',
+    level: 'A2',
+    tags: const ['daily'],
+    totalXp: 120,
+    estimatedDuration: 30,
+    totalLessons: 8,
+    isPublished: true,
+    createdAt: now,
+    updatedAt: now,
+    isEnrolled: true,
+    userProgress: progress,
+  );
+}
+
+SkillScore _skill(SkillType skill, {required double score}) {
+  return SkillScore(
+    skill: skill,
+    score: score,
+    confidence: 0.8,
+    estimatedLevel: 'A2',
+    accuracy: 0.7,
+    trend: 'stable',
+    exercisesCompleted: 12,
+  );
+}
+
+DailyChallengeEntity _challenge({
+  required String category,
+  required int current,
+  required int target,
+}) {
+  return DailyChallengeEntity(
+    id: 'challenge-1',
+    title: 'Review words',
+    description: 'Review 3 due words',
+    icon: 'style',
+    category: category,
+    target: target,
+    current: current,
+    xpReward: 20,
+    isCompleted: current >= target,
+    expiresAt: DateTime(2026, 7, 1),
+  );
+}
diff --git a/flutter-app/test/features/level/placement_test_payload_test.dart b/flutter-app/test/features/level/placement_test_payload_test.dart
new file mode 100644
index 00000000..4959d0f0
--- /dev/null
+++ b/flutter-app/test/features/level/placement_test_payload_test.dart
@@ -0,0 +1,27 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/level/data/datasources/proficiency_data_source.dart';
+
+void main() {
+  group('buildPlacementAnswerPayload', () {
+    test(
+      'converts answer map into backend list contract sorted by question id',
+      () {
+        final payload = buildPlacementAnswerPayload({'10': 2, '2': 0, '1': 3});
+
+        expect(payload, [
+          {'question_id': 1, 'selected_option': 3},
+          {'question_id': 2, 'selected_option': 0},
+          {'question_id': 10, 'selected_option': 2},
+        ]);
+      },
+    );
+
+    test('skips non-numeric question ids', () {
+      final payload = buildPlacementAnswerPayload({'intro': 1, '3': 2});
+
+      expect(payload, [
+        {'question_id': 3, 'selected_option': 2},
+      ]);
+    });
+  });
+}
diff --git a/flutter-app/test/features/lexi_chat/data/repositories/lexi_chat_repository_impl_metadata_test.dart b/flutter-app/test/features/lexi_chat/data/repositories/lexi_chat_repository_impl_metadata_test.dart
index 24f6a076..eece1442 100644
--- a/flutter-app/test/features/lexi_chat/data/repositories/lexi_chat_repository_impl_metadata_test.dart
+++ b/flutter-app/test/features/lexi_chat/data/repositories/lexi_chat_repository_impl_metadata_test.dart
@@ -180,6 +180,23 @@ void main() {
       expect(dataSource.lastPagedSessionId, 'session_1');
     });
 
+    test(
+      'rethrows forbidden metadata errors without calling paged endpoint',
+      () async {
+        dataSource.metadataError = Exception(
+          'Request /lexi/sessions/session_1/messages/metadata failed with status 403',
+        );
+
+        await expectLater(
+          repository.getMessagesPaged(sessionId: 'session_1'),
+          throwsA(isA<Exception>()),
+        );
+
+        expect(dataSource.metadataCalls, 1);
+        expect(dataSource.pagedCalls, 0);
+      },
+    );
+
     test('skips metadata check when cursor is provided', () async {
       dataSource.pagedResult = const LexiMessagesPage(
         messages: [],
diff --git a/flutter-app/test/features/lexi_chat/presentation/providers/lexi_chat_provider_test.dart b/flutter-app/test/features/lexi_chat/presentation/providers/lexi_chat_provider_test.dart
index 9585c1be..0214f289 100644
--- a/flutter-app/test/features/lexi_chat/presentation/providers/lexi_chat_provider_test.dart
+++ b/flutter-app/test/features/lexi_chat/presentation/providers/lexi_chat_provider_test.dart
@@ -12,6 +12,9 @@ class _FakeLexiChatRepository implements LexiChatRepository {
   int sendCalls = 0;
   int streamCalls = 0;
   String? lastIdempotencyKey;
+  String? lastNativeLanguage;
+  String? lastStreamNativeLanguage;
+  Object? pagedError;
   Stream<LexiStreamEvent> Function()? streamFactory;
 
   @override
@@ -39,6 +42,7 @@ class _FakeLexiChatRepository implements LexiChatRepository {
     int limit = 50,
     String? cursor,
   }) async {
+    if (pagedError != null) throw pagedError!;
     return const LexiMessagesPage(
       messages: [],
       hasMore: false,
@@ -67,11 +71,13 @@ class _FakeLexiChatRepository implements LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
     String? idempotencyKey,
   }) async {
     sendCalls += 1;
     lastIdempotencyKey = idempotencyKey;
+    lastNativeLanguage = nativeLanguage;
     return LexiMessage(
       id: 'assistant-$sendCalls',
       role: 'assistant',
@@ -89,9 +95,11 @@ class _FakeLexiChatRepository implements LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
   }) {
     streamCalls += 1;
+    lastStreamNativeLanguage = nativeLanguage;
     return streamFactory?.call() ??
         Stream<LexiStreamEvent>.fromIterable([
           const LexiStreamChunk('ok'),
@@ -146,6 +154,39 @@ void main() {
       expect(provider.messages.last.content, 'ok');
     });
 
+    test('defaults nativeLanguage to vi and forwards setNativeLanguage', () async {
+      final repo = _FakeLexiChatRepository();
+      final provider = LexiChatProvider(repository: repo, aiClient: AiApiClient());
+      addTearDown(provider.dispose);
+
+      expect(provider.nativeLanguage, 'vi');
+
+      await provider.sendMessage('hello', userId: 'user-1');
+      expect(repo.lastNativeLanguage, 'vi');
+
+      provider.setNativeLanguage('ja');
+      expect(provider.nativeLanguage, 'ja');
+
+      await provider.sendMessage('hello again', userId: 'user-1');
+      expect(repo.lastNativeLanguage, 'ja');
+    });
+
+    test('forwards nativeLanguage to streaming send', () async {
+      final repo = _FakeLexiChatRepository();
+      final provider = LexiChatProvider(repository: repo, aiClient: AiApiClient());
+      addTearDown(provider.dispose);
+
+      provider.setNativeLanguage('ko');
+      await provider.sendMessageStreaming('hello', userId: 'user-1');
+
+      expect(repo.lastStreamNativeLanguage, 'ko');
+
+      // Let the constructor's fire-and-forget _loadSavedSessions() finish
+      // before addTearDown disposes the provider (it calls notifyListeners()
+      // on completion, which throws if disposal already happened).
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+    });
+
     test('keeps streamed text when SSE has chunks but no done event', () async {
       final repo = _FakeLexiChatRepository()
         ..streamFactory = () => Stream<LexiStreamEvent>.fromIterable([
@@ -167,5 +208,32 @@ void main() {
       expect(provider.messages.last.content, 'Hi there');
       expect(provider.messages.last.syncStatus, 'synced');
     });
+
+    test('clears selected session when backend returns forbidden', () async {
+      final repo = _FakeLexiChatRepository()
+        ..pagedError = Exception(
+          'Request /lexi/sessions/old/messages/metadata failed with status 403',
+        );
+      final provider = LexiChatProvider(
+        repository: repo,
+        aiClient: AiApiClient(),
+      );
+      addTearDown(provider.dispose);
+
+      await provider.selectSession(
+        LexiSessionSummary(
+          sessionId: 'old',
+          userId: 'other-user',
+          title: 'Old session',
+          createdAt: DateTime.parse('2026-05-30T00:00:00Z'),
+          updatedAt: DateTime.parse('2026-05-30T00:00:00Z'),
+          messageCount: 1,
+        ),
+      );
+
+      expect(provider.session, isNull);
+      expect(provider.messages, isEmpty);
+      expect(provider.error, contains('another account'));
+    });
   });
 }
diff --git a/flutter-app/test/features/mistakes/mistake_notebook_remote_datasource_test.dart b/flutter-app/test/features/mistakes/mistake_notebook_remote_datasource_test.dart
new file mode 100644
index 00000000..500770ce
--- /dev/null
+++ b/flutter-app/test/features/mistakes/mistake_notebook_remote_datasource_test.dart
@@ -0,0 +1,143 @@
+import 'dart:convert';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/testing.dart';
+import 'package:lexilingo_app/core/network/api_client.dart';
+import 'package:lexilingo_app/core/network/network_info.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_remote_datasource.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+
+void main() {
+  group('ApiMistakeNotebookRemoteDataSource', () {
+    test(
+      'posts Flutter mistake payload to backend mistakes endpoint',
+      () async {
+        late http.Request capturedRequest;
+        final dataSource = _dataSource(
+          MockClient((request) async {
+            capturedRequest = request;
+            final body = jsonDecode(request.body) as Map<String, dynamic>;
+            expect(request.method, 'POST');
+            expect(request.url.path, '/api/v1/mistakes');
+            expect(body['id'], 'mistake_remote');
+            expect(body['source_type'], 'news_quiz');
+            expect(body['selected_answer'], 'A');
+
+            return _jsonResponse({
+              'data': _entryJson(id: body['id'] as String),
+            });
+          }),
+        );
+
+        final saved = await dataSource.saveMistake(
+          _entry(id: 'mistake_remote'),
+        );
+
+        expect(
+          capturedRequest.headers['content-type'],
+          contains('application/json'),
+        );
+        expect(saved.id, 'mistake_remote');
+      },
+    );
+
+    test('lists entries from envelope list response', () async {
+      final dataSource = _dataSource(
+        MockClient((request) async {
+          expect(request.method, 'GET');
+          expect(request.url.path, '/api/v1/mistakes');
+          expect(request.url.queryParameters['status'], 'all');
+          expect(request.url.queryParameters['limit'], '100');
+          expect(request.url.queryParameters['offset'], '0');
+
+          return _jsonResponse({
+            'data': [_entryJson(id: 'remote-1')],
+          });
+        }),
+      );
+
+      final entries = await dataSource.getEntries();
+
+      expect(entries.map((entry) => entry.id), ['remote-1']);
+    });
+
+    test('patches review and deletes by id', () async {
+      final requests = <String>[];
+      final dataSource = _dataSource(
+        MockClient((request) async {
+          requests.add('${request.method} ${request.url.path}');
+          if (request.method == 'PATCH') {
+            return _jsonResponse({'data': _entryJson(id: 'remote-1')});
+          }
+          return _jsonResponse({'message': 'Mistake deleted'});
+        }),
+      );
+
+      final reviewed = await dataSource.markReviewed('remote/1');
+      await dataSource.delete('remote/1');
+
+      expect(reviewed.id, 'remote-1');
+      expect(requests, [
+        'PATCH /api/v1/mistakes/remote%2F1/review',
+        'DELETE /api/v1/mistakes/remote%2F1',
+      ]);
+    });
+  });
+}
+
+ApiMistakeNotebookRemoteDataSource _dataSource(http.Client client) {
+  return ApiMistakeNotebookRemoteDataSource(
+    apiClient: ApiClient(
+      client: client,
+      baseUrl: 'https://api.example.test/api/v1',
+      enableLogging: false,
+      networkInfo: _AlwaysConnectedNetworkInfo(),
+    ),
+  );
+}
+
+http.Response _jsonResponse(Map<String, dynamic> body) {
+  return http.Response(
+    jsonEncode(body),
+    200,
+    headers: {'content-type': 'application/json'},
+  );
+}
+
+MistakeNotebookEntry _entry({required String id}) {
+  return MistakeNotebookEntry(
+    id: id,
+    sourceType: 'news_quiz',
+    sourceId: 'article-1',
+    sourceTitle: 'Demo article',
+    question: 'What happened?',
+    selectedAnswer: 'A',
+    correctAnswer: 'B',
+    explanation: 'Because the text says so.',
+    skill: 'reading',
+    createdAt: DateTime(2026),
+  );
+}
+
+Map<String, dynamic> _entryJson({required String id}) => {
+  'id': id,
+  'source_type': 'news_quiz',
+  'source_id': 'article-1',
+  'source_title': 'Demo article',
+  'question': 'What happened?',
+  'selected_answer': 'A',
+  'correct_answer': 'B',
+  'explanation': 'Because the text says so.',
+  'skill': 'reading',
+  'status': 'open',
+  'created_at': DateTime(2026).toIso8601String(),
+  'updated_at': DateTime(2026).toIso8601String(),
+  'review_count': 0,
+  'attempt_count': 1,
+};
+
+class _AlwaysConnectedNetworkInfo implements NetworkInfo {
+  @override
+  Future<bool> get isConnected async => true;
+}
diff --git a/flutter-app/test/features/mistakes/mistake_notebook_repository_test.dart b/flutter-app/test/features/mistakes/mistake_notebook_repository_test.dart
new file mode 100644
index 00000000..4ecc27b4
--- /dev/null
+++ b/flutter-app/test/features/mistakes/mistake_notebook_repository_test.dart
@@ -0,0 +1,240 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/core/services/user_scope_service.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_remote_datasource.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:lexilingo_app/features/mistakes/domain/mistake_notebook_entry.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  group('MistakeNotebookRepository', () {
+    setUp(() {
+      SharedPreferences.setMockInitialValues({});
+    });
+
+    test('saves entries sorted by review state and recency', () async {
+      final repository = MistakeNotebookRepository();
+      final older = _entry(id: 'older', createdAt: DateTime(2026));
+      final newer = _entry(id: 'newer', createdAt: DateTime(2026, 1, 2));
+
+      await repository.saveMistake(older);
+      await repository.saveMistake(newer);
+
+      final entries = await repository.getEntries();
+
+      expect(entries.map((entry) => entry.id), ['newer', 'older']);
+    });
+
+    test('upserts repeated mistake and makes it unreviewed again', () async {
+      final repository = MistakeNotebookRepository();
+      final mistake = _entry(id: 'repeat', createdAt: DateTime(2026));
+
+      await repository.saveMistake(mistake);
+      await repository.markReviewed('repeat');
+      await repository.saveMistake(
+        mistake.copyWith(selectedAnswer: 'C', createdAt: DateTime(2026, 1, 3)),
+      );
+
+      final entries = await repository.getEntries();
+
+      expect(entries, hasLength(1));
+      expect(entries.single.selectedAnswer, 'C');
+      expect(entries.single.isReviewed, isFalse);
+      expect(entries.single.reviewCount, 1);
+    });
+
+    test('marks entries reviewed and clears reviewed items', () async {
+      final repository = MistakeNotebookRepository();
+
+      await repository.saveMistake(_entry(id: 'a'));
+      await repository.saveMistake(_entry(id: 'b'));
+      await repository.markReviewed('a');
+
+      var entries = await repository.getEntries();
+      expect(entries.first.id, 'b');
+      expect(entries.last.id, 'a');
+      expect(entries.last.reviewCount, 1);
+
+      await repository.clearReviewed();
+      entries = await repository.getEntries();
+
+      expect(entries.map((entry) => entry.id), ['b']);
+    });
+
+    test('buildId is stable for identical quiz context', () {
+      final first = MistakeNotebookEntry.buildId(
+        sourceType: 'book_quiz',
+        sourceId: 'book-1',
+        questionId: 'q1',
+        selectedAnswer: 'A',
+      );
+      final second = MistakeNotebookEntry.buildId(
+        sourceType: 'book_quiz',
+        sourceId: 'book-1',
+        questionId: 'q1',
+        selectedAnswer: 'A',
+      );
+
+      expect(first, second);
+    });
+
+    test('syncs saved mistakes to remote datasource when available', () async {
+      final remote = _FakeMistakeRemoteDataSource();
+      final repository = MistakeNotebookRepository(remoteDataSource: remote);
+      final mistake = _entry(id: 'remote-save');
+
+      await repository.saveMistake(mistake);
+
+      expect(remote.saved.map((entry) => entry.id), ['remote-save']);
+      final entries = await repository.getEntries();
+      expect(entries.map((entry) => entry.id), ['remote-save']);
+    });
+
+    test('queues failed remote saves and retries on next load', () async {
+      final remote = _FakeMistakeRemoteDataSource(shouldFail: true);
+      final repository = MistakeNotebookRepository(remoteDataSource: remote);
+      final mistake = _entry(id: 'queued');
+
+      await repository.saveMistake(mistake);
+
+      expect(remote.saved, isEmpty);
+      remote.shouldFail = false;
+
+      final entries = await repository.getEntries();
+
+      expect(entries.map((entry) => entry.id), ['queued']);
+      expect(remote.saved.map((entry) => entry.id), ['queued']);
+      expect(remote.saveCalls, 2);
+    });
+
+    test(
+      'does not flush queued user A operations while user B is active',
+      () async {
+        final remote = _FakeMistakeRemoteDataSource(shouldFail: true);
+        final repository = MistakeNotebookRepository(remoteDataSource: remote);
+
+        await UserScopeService.setActiveUserId('user-a');
+        await repository.saveMistake(_entry(id: 'queued-user-a'));
+        expect(remote.saveCalls, 1);
+
+        remote.shouldFail = false;
+        await UserScopeService.setActiveUserId('user-b');
+        await repository.getEntries();
+        expect(remote.saveCalls, 1);
+        expect(remote.saved, isEmpty);
+
+        await UserScopeService.setActiveUserId('user-a');
+        await repository.getEntries();
+        expect(remote.saveCalls, 2);
+        expect(remote.saved.map((entry) => entry.id), ['queued-user-a']);
+      },
+    );
+
+    test('suppresses remote entries while delete is still pending', () async {
+      final remote = _FakeMistakeRemoteDataSource();
+      remote.saved.add(_entry(id: 'delete-pending'));
+      final repository = MistakeNotebookRepository(remoteDataSource: remote);
+
+      await repository.getEntries();
+      remote.failDeletes = true;
+      await repository.delete('delete-pending');
+
+      final entries = await repository.getEntries();
+
+      expect(entries, isEmpty);
+      expect(remote.saved.map((entry) => entry.id), ['delete-pending']);
+    });
+
+    test('syncs review and delete operations to remote datasource', () async {
+      final remote = _FakeMistakeRemoteDataSource();
+      final repository = MistakeNotebookRepository(remoteDataSource: remote);
+
+      await repository.saveMistake(_entry(id: 'review-delete'));
+      await repository.markReviewed('review-delete');
+      await repository.delete('review-delete');
+
+      expect(remote.reviewedIds, ['review-delete']);
+      expect(remote.deletedIds, ['review-delete']);
+    });
+
+    test('scopes local entries by active user', () async {
+      final repository = MistakeNotebookRepository();
+
+      await UserScopeService.setActiveUserId('user-a');
+      await repository.saveMistake(_entry(id: 'user-a-entry'));
+
+      await UserScopeService.setActiveUserId('user-b');
+      expect(await repository.getEntries(), isEmpty);
+
+      await repository.saveMistake(_entry(id: 'user-b-entry'));
+      expect((await repository.getEntries()).map((entry) => entry.id), [
+        'user-b-entry',
+      ]);
+
+      await UserScopeService.setActiveUserId('user-a');
+      expect((await repository.getEntries()).map((entry) => entry.id), [
+        'user-a-entry',
+      ]);
+    });
+  });
+}
+
+MistakeNotebookEntry _entry({required String id, DateTime? createdAt}) {
+  return MistakeNotebookEntry(
+    id: id,
+    sourceType: 'book_quiz',
+    sourceId: 'book-1',
+    sourceTitle: 'Demo book',
+    question: 'What happened?',
+    selectedAnswer: 'A',
+    correctAnswer: 'B',
+    explanation: 'Because the text says so.',
+    skill: 'reading',
+    createdAt: createdAt ?? DateTime(2026),
+  );
+}
+
+class _FakeMistakeRemoteDataSource implements MistakeNotebookRemoteDataSource {
+  final saved = <MistakeNotebookEntry>[];
+  final reviewedIds = <String>[];
+  final deletedIds = <String>[];
+  bool shouldFail;
+  bool failDeletes = false;
+  int saveCalls = 0;
+
+  _FakeMistakeRemoteDataSource({this.shouldFail = false});
+
+  @override
+  Future<List<MistakeNotebookEntry>> getEntries({String status = 'all'}) async {
+    if (shouldFail) throw Exception('offline');
+    return saved;
+  }
+
+  @override
+  Future<MistakeNotebookEntry> saveMistake(MistakeNotebookEntry entry) async {
+    saveCalls++;
+    if (shouldFail) throw Exception('offline');
+    saved.removeWhere((item) => item.id == entry.id);
+    saved.add(entry);
+    return entry;
+  }
+
+  @override
+  Future<MistakeNotebookEntry> markReviewed(String id) async {
+    if (shouldFail) throw Exception('offline');
+    reviewedIds.add(id);
+    return saved.firstWhere((entry) => entry.id == id);
+  }
+
+  @override
+  Future<MistakeNotebookEntry> reopen(String id) async {
+    if (shouldFail) throw Exception('offline');
+    return saved.firstWhere((entry) => entry.id == id);
+  }
+
+  @override
+  Future<void> delete(String id) async {
+    if (shouldFail || failDeletes) throw Exception('offline');
+    deletedIds.add(id);
+    saved.removeWhere((entry) => entry.id == id);
+  }
+}
diff --git a/flutter-app/test/features/news/presentation/providers/news_provider_mistakes_test.dart b/flutter-app/test/features/news/presentation/providers/news_provider_mistakes_test.dart
new file mode 100644
index 00000000..f2843559
--- /dev/null
+++ b/flutter-app/test/features/news/presentation/providers/news_provider_mistakes_test.dart
@@ -0,0 +1,62 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/mistakes/data/mistake_notebook_repository.dart';
+import 'package:lexilingo_app/features/news/data/repositories/news_repository.dart';
+import 'package:lexilingo_app/features/news/domain/entities/news_entities.dart';
+import 'package:lexilingo_app/features/news/presentation/providers/news_provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  group('NewsProvider mistake capture', () {
+    setUp(() {
+      SharedPreferences.setMockInitialValues({});
+    });
+
+    test(
+      'uses requested article id when quiz article metadata is unavailable',
+      () async {
+        final repository = MistakeNotebookRepository();
+        final provider = NewsProvider(
+          repository: _FakeNewsRepository(
+            quiz: const NewsQuiz(
+              questions: [
+                QuizQuestion(
+                  id: 1,
+                  type: 'reading',
+                  question: 'What is the main idea?',
+                  options: ['A', 'B', 'C'],
+                  correctIndex: 1,
+                  explanation: 'The article supports B.',
+                ),
+              ],
+              totalQuestions: 1,
+            ),
+          ),
+          mistakeRepository: repository,
+        );
+
+        await provider.loadQuiz('article-123');
+        provider.answerQuestion(1, 0);
+        provider.submitQuiz();
+        await Future<void>.delayed(Duration.zero);
+
+        final entries = await repository.getEntries();
+
+        expect(entries, hasLength(1));
+        expect(entries.single.sourceType, 'news_quiz');
+        expect(entries.single.sourceId, 'article-123');
+        expect(entries.single.sourceTitle, 'News quiz');
+        expect(entries.single.selectedAnswer, 'A');
+        expect(entries.single.correctAnswer, 'B');
+      },
+    );
+  });
+}
+
+class _FakeNewsRepository extends NewsRepository {
+  final NewsQuiz quiz;
+
+  _FakeNewsRepository({required this.quiz});
+
+  @override
+  Future<NewsQuiz?> getQuiz(String articleId) async => quiz;
+}
diff --git a/flutter-app/test/features/notifications/notification_entity_test.dart b/flutter-app/test/features/notifications/notification_entity_test.dart
index db926e30..98107042 100644
--- a/flutter-app/test/features/notifications/notification_entity_test.dart
+++ b/flutter-app/test/features/notifications/notification_entity_test.dart
@@ -265,6 +265,30 @@ void main() {
       expect(notification.iconIdentifier, 'schedule');
     });
 
+    test('should parse common achievement aliases', () {
+      for (final type in ['achievement_unlocked', 'achievements']) {
+        final notification = NotificationEntity.fromFcm(
+          id: type,
+          title: 'Achievement',
+          body: 'Body',
+          data: {'type': type},
+        );
+
+        expect(notification.type, NotificationType.achievement);
+      }
+    });
+
+    test('should parse new_content_available alias', () {
+      final notification = NotificationEntity.fromFcm(
+        id: '1',
+        title: 'New content',
+        body: 'Body',
+        data: {'type': 'new_content_available'},
+      );
+
+      expect(notification.type, NotificationType.newContent);
+    });
+
     test('should default to general type for unknown', () {
       final notification = NotificationEntity.fromFcm(
         id: '1',
@@ -327,6 +351,95 @@ void main() {
     });
   });
 
+  group('NotificationEntity - navigation destination', () {
+    test('destinationRoute should prefer explicit data route', () {
+      final notification = NotificationEntity(
+        id: '1',
+        type: NotificationType.achievement,
+        title: 'Test',
+        body: 'Body',
+        timestamp: DateTime.now(),
+        data: {'route': '/custom-route'},
+      );
+
+      expect(notification.destinationRoute, '/custom-route');
+      expect(notification.opensRoot, false);
+    });
+
+    test('opensRoot should be true for root route aliases', () {
+      for (final route in ['/', '/home', 'home', 'root']) {
+        final notification = NotificationEntity(
+          id: route,
+          type: NotificationType.general,
+          title: 'Test',
+          body: 'Body',
+          timestamp: DateTime.now(),
+          data: {'route': route},
+        );
+
+        expect(notification.opensRoot, true);
+        expect(notification.destinationRoute, isNull);
+      }
+    });
+
+    test('opensRoot should be true for starter reward payloads', () {
+      final notification = NotificationEntity.fromFcm(
+        id: 'starter',
+        title: 'Starter reward',
+        body: 'Claim your reward',
+        data: {'type': 'starter_reward'},
+      );
+
+      expect(notification.opensRoot, true);
+      expect(notification.destinationRoute, isNull);
+    });
+
+    test('destinationRoute should map known notification types', () {
+      final expectedRoutes = {
+        NotificationType.streakReminder: '/today-plan',
+        NotificationType.lessonReminder: '/courses',
+        NotificationType.vocabularyReviewReminder: '/vocabulary/review',
+        NotificationType.achievement: '/achievements',
+        NotificationType.newContent: '/courses',
+        NotificationType.weeklySummary: '/profile',
+        NotificationType.social: '/social',
+      };
+
+      for (final entry in expectedRoutes.entries) {
+        final notification = NotificationEntity(
+          id: entry.key.name,
+          type: entry.key,
+          title: 'Test',
+          body: 'Body',
+          timestamp: DateTime.now(),
+        );
+
+        expect(notification.destinationRoute, entry.value);
+      }
+    });
+
+    test(
+      'destinationRoute should be null for general/system without route',
+      () {
+        for (final type in [
+          NotificationType.general,
+          NotificationType.system,
+        ]) {
+          final notification = NotificationEntity(
+            id: type.name,
+            type: type,
+            title: 'Test',
+            body: 'Body',
+            timestamp: DateTime.now(),
+          );
+
+          expect(notification.destinationRoute, isNull);
+          expect(notification.opensRoot, false);
+        }
+      },
+    );
+  });
+
   group('NotificationGroup', () {
     test('should create NotificationGroup with notifications', () {
       final notifications = [
diff --git a/flutter-app/test/features/offline/offline_sync_snapshot_test.dart b/flutter-app/test/features/offline/offline_sync_snapshot_test.dart
new file mode 100644
index 00000000..7ea03232
--- /dev/null
+++ b/flutter-app/test/features/offline/offline_sync_snapshot_test.dart
@@ -0,0 +1,31 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/core/services/background_sync_queue_service.dart';
+import 'package:lexilingo_app/features/offline/presentation/pages/offline_sync_center_page.dart';
+
+void main() {
+  group('OfflineSyncSnapshot', () {
+    test('reports active user scope when user id is present', () {
+      const snapshot = OfflineSyncSnapshot(
+        isOnline: true,
+        cacheSize: 3,
+        cacheCountsByType: {'news': 2, 'book': 1},
+        activeUserScope: 'user-123',
+        queueSummary: SyncQueueSummary.unsupported,
+      );
+
+      expect(snapshot.hasActiveUser, isTrue);
+    });
+
+    test('reports no active user scope when user id is missing', () {
+      const snapshot = OfflineSyncSnapshot(
+        isOnline: false,
+        cacheSize: 0,
+        cacheCountsByType: {},
+        activeUserScope: null,
+        queueSummary: SyncQueueSummary.unsupported,
+      );
+
+      expect(snapshot.hasActiveUser, isFalse);
+    });
+  });
+}
diff --git a/flutter-app/test/features/practice/practice_lab_models_test.dart b/flutter-app/test/features/practice/practice_lab_models_test.dart
new file mode 100644
index 00000000..81c4f5dc
--- /dev/null
+++ b/flutter-app/test/features/practice/practice_lab_models_test.dart
@@ -0,0 +1,89 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/features/level/domain/entities/proficiency_entity.dart';
+import 'package:lexilingo_app/features/practice/presentation/widgets/practice_lab_models.dart';
+
+void main() {
+  group('Practice Lab models', () {
+    test('buildPracticeLabItems returns skill labs plus mistake notebook', () {
+      final items = buildPracticeLabItems();
+
+      expect(items, hasLength(7));
+      expect(items.map((item) => item.destination), [
+        PracticeLabDestination.vocabularyReview,
+        PracticeLabDestination.voicePractice,
+        PracticeLabDestination.podcast,
+        PracticeLabDestination.news,
+        PracticeLabDestination.games,
+        PracticeLabDestination.mistakeNotebook,
+        PracticeLabDestination.lexi,
+      ]);
+      expect(items.map((item) => item.skill), [
+        SkillType.vocabulary,
+        SkillType.speaking,
+        SkillType.listening,
+        SkillType.reading,
+        SkillType.grammar,
+        SkillType.reading,
+        SkillType.writing,
+      ]);
+    });
+
+    test('marks weakest skills as recommended', () {
+      final items = buildPracticeLabItems(
+        weakestSkills: const [
+          SkillScore(
+            skill: SkillType.grammar,
+            score: 32,
+            confidence: 0.8,
+            estimatedLevel: 'A2',
+            accuracy: 0.64,
+            trend: 'stable',
+            exercisesCompleted: 12,
+          ),
+          SkillScore(
+            skill: SkillType.writing,
+            score: 41,
+            confidence: 0.7,
+            estimatedLevel: 'B1',
+            accuracy: 0.68,
+            trend: 'declining',
+            exercisesCompleted: 9,
+          ),
+        ],
+      );
+
+      final recommended = items
+          .where((item) => item.recommended)
+          .map((item) => item.skill)
+          .toList();
+
+      expect(recommended, [SkillType.grammar, SkillType.writing]);
+    });
+
+    test(
+      'recommendedPracticeItems falls back to first items without scores',
+      () {
+        final items = buildPracticeLabItems();
+
+        final recommended = recommendedPracticeItems(items: items);
+
+        expect(recommended, hasLength(2));
+        expect(recommended.map((item) => item.skill), [
+          SkillType.vocabulary,
+          SkillType.speaking,
+        ]);
+      },
+    );
+
+    test('marks writing practice as premium-only soft gate', () {
+      final items = buildPracticeLabItems();
+
+      final premiumItems = items
+          .where((item) => item.premiumOnly)
+          .map((item) => item.skill)
+          .toList();
+
+      expect(premiumItems, [SkillType.writing]);
+    });
+  });
+}
diff --git a/flutter-app/test/features/progress/streak_provider_milestone_test.dart b/flutter-app/test/features/progress/streak_provider_milestone_test.dart
index ec326653..aa7df0dc 100644
--- a/flutter-app/test/features/progress/streak_provider_milestone_test.dart
+++ b/flutter-app/test/features/progress/streak_provider_milestone_test.dart
@@ -20,16 +20,16 @@ class _StubProgressRepository implements ProgressRepository {
 
   @override
   Future<Either<Failure, StreakEntity>> getMyStreak() async => Right(
-        StreakEntity(
-          currentStreak: updateResult.currentStreak,
-          longestStreak: updateResult.longestStreak,
-          totalDaysActive: updateResult.totalDaysActive,
-          lastActivityDate: DateTime.now().toIso8601String(),
-          freezeCount: updateResult.freezeCount,
-          isActiveToday: true,
-          streakAtRisk: false,
-        ),
-      );
+    StreakEntity(
+      currentStreak: updateResult.currentStreak,
+      longestStreak: updateResult.longestStreak,
+      totalDaysActive: updateResult.totalDaysActive,
+      lastActivityDate: DateTime.now().toIso8601String(),
+      freezeCount: updateResult.freezeCount,
+      isActiveToday: true,
+      streakAtRisk: false,
+    ),
+  );
 
   @override
   Future<Either<Failure, ProgressStatsEntity>> getMyProgress() async =>
@@ -37,19 +37,17 @@ class _StubProgressRepository implements ProgressRepository {
 
   @override
   Future<Either<Failure, CourseProgressWithUnits>> getCourseProgress(
-          String courseId) async =>
-      throw UnimplementedError();
+    String courseId,
+  ) async => throw UnimplementedError();
 
   @override
   Future<Either<Failure, LessonCompletionResult>> completeLesson({
     required String lessonId,
     required double score,
-  }) async =>
-      throw UnimplementedError();
+  }) async => throw UnimplementedError();
 
   @override
-  Future<Either<Failure, int>> getTotalXp() async =>
-      throw UnimplementedError();
+  Future<Either<Failure, int>> getTotalXp() async => throw UnimplementedError();
 
   @override
   Future<Either<Failure, WeeklyProgressEntity>> getWeeklyProgress() async =>
@@ -73,18 +71,18 @@ class _StubProgressRepository implements ProgressRepository {
 
   @override
   Future<Either<Failure, Map<String, dynamic>>> claimChallengeReward(
-          String challengeId) async =>
-      throw UnimplementedError();
+    String challengeId,
+  ) async => throw UnimplementedError();
 }
 
 StreakUpdateResult _result(int streak) => StreakUpdateResult(
-      currentStreak: streak,
-      longestStreak: streak,
-      totalDaysActive: streak,
-      freezeCount: 0,
-      streakIncreased: true,
-      streakSaved: false,
-    );
+  currentStreak: streak,
+  longestStreak: streak,
+  totalDaysActive: streak,
+  freezeCount: 0,
+  streakIncreased: true,
+  streakSaved: false,
+);
 
 void main() {
   group('StreakProvider.milestoneJustReached', () {
@@ -150,25 +148,25 @@ void main() {
   });
 
   group('StreakEntity.isMilestone', () {
-    StreakEntity _entity(int streak) => StreakEntity(
-          currentStreak: streak,
-          longestStreak: streak,
-          totalDaysActive: streak,
-          lastActivityDate: DateTime.now().toIso8601String(),
-          freezeCount: 0,
-          isActiveToday: true,
-          streakAtRisk: false,
-        );
+    StreakEntity entity(int streak) => StreakEntity(
+      currentStreak: streak,
+      longestStreak: streak,
+      totalDaysActive: streak,
+      lastActivityDate: DateTime.now().toIso8601String(),
+      freezeCount: 0,
+      isActiveToday: true,
+      streakAtRisk: false,
+    );
 
     for (final days in [7, 14, 30, 60, 100, 365]) {
       test('returns true for $days days', () {
-        expect(_entity(days).isMilestone, isTrue);
+        expect(entity(days).isMilestone, isTrue);
       });
     }
 
     for (final days in [1, 6, 8, 29, 31, 101]) {
       test('returns false for $days days', () {
-        expect(_entity(days).isMilestone, isFalse);
+        expect(entity(days).isMilestone, isFalse);
       });
     }
   });
diff --git a/flutter-app/test/features/vocabulary/data/datasources/vocabulary_remote_datasource_test.dart b/flutter-app/test/features/vocabulary/data/datasources/vocabulary_remote_datasource_test.dart
index 6008a272..6a5c74c4 100644
--- a/flutter-app/test/features/vocabulary/data/datasources/vocabulary_remote_datasource_test.dart
+++ b/flutter-app/test/features/vocabulary/data/datasources/vocabulary_remote_datasource_test.dart
@@ -58,4 +58,55 @@ void main() {
       expect(items.single.vietnameseTranslation, 'khám phá');
     });
   });
+
+  group('VocabularyRemoteDataSourceImpl.getDeckItems', () {
+    test(
+      'parses a backend list wrapped by ApiClient in the data field',
+      () async {
+        final httpClient = MockClient((request) async {
+          expect(request.url.path, '/vocabulary/decks/deck-1/items');
+
+          return http.Response(
+            jsonEncode([
+              {
+                'id': '1a6f7e8e-6e18-49e5-88a4-4e82d8db56e0',
+                'user_id': '2b6f7e8e-6e18-49e5-88a4-4e82d8db56e0',
+                'vocabulary_id': '3c6f7e8e-6e18-49e5-88a4-4e82d8db56e0',
+                'status': 'learning',
+                'ease_factor': 2.5,
+                'interval': 1,
+                'repetitions': 0,
+                'next_review_date': '2026-06-06T00:00:00Z',
+                'last_reviewed_at': null,
+                'total_reviews': 0,
+                'correct_reviews': 0,
+                'streak': 0,
+                'longest_streak': 0,
+                'total_xp_earned': 0,
+                'notes': null,
+                'added_at': '2026-06-05T00:00:00Z',
+              },
+            ]),
+            200,
+            headers: {'content-type': 'application/json'},
+          );
+        });
+        final apiClient = ApiClient(
+          client: httpClient,
+          baseUrl: 'http://test.local',
+          networkInfo: _AlwaysConnectedNetworkInfo(),
+          enableLogging: false,
+        );
+        final dataSource = VocabularyRemoteDataSourceImpl(apiClient: apiClient);
+
+        final items = await dataSource.getDeckItems('deck-1');
+
+        expect(items, hasLength(1));
+        expect(
+          items.single.vocabularyId,
+          '3c6f7e8e-6e18-49e5-88a4-4e82d8db56e0',
+        );
+      },
+    );
+  });
 }
diff --git a/flutter-app/test/features/vocabulary/presentation/providers/quiz_provider_test.dart b/flutter-app/test/features/vocabulary/presentation/providers/quiz_provider_test.dart
new file mode 100644
index 00000000..21f60c33
--- /dev/null
+++ b/flutter-app/test/features/vocabulary/presentation/providers/quiz_provider_test.dart
@@ -0,0 +1,257 @@
+import 'package:dartz/dartz.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lexilingo_app/core/error/failures.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/quiz_question_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/review_session_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/user_vocabulary_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/entities/vocabulary_item_entity.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/repositories/vocabulary_repository.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/usecases/get_due_vocabulary_usecase.dart';
+import 'package:lexilingo_app/features/vocabulary/domain/usecases/submit_review_usecase.dart';
+import 'package:lexilingo_app/features/vocabulary/presentation/providers/quiz_provider.dart';
+
+VocabularyItemEntity _item(String id, String word, String definition) =>
+    VocabularyItemEntity(
+      id: id,
+      word: word,
+      definition: definition,
+      partOfSpeech: 'noun',
+      difficultyLevel: 'B1',
+      createdAt: DateTime.utc(2026, 6, 8),
+    );
+
+UserVocabularyEntity _userVocab(String id, String vocabId) =>
+    UserVocabularyEntity(
+      id: id,
+      userId: 'user-1',
+      vocabularyId: vocabId,
+      status: VocabularyStatus.reviewing,
+      nextReviewDate: DateTime.utc(2026, 6, 8),
+      addedAt: DateTime.utc(2026, 6, 1),
+    );
+
+class _FakeQuizRepository extends Fake implements VocabularyRepository {
+  final List<UserVocabularyEntity> due;
+  final Map<String, VocabularyItemEntity> items;
+  final List<VocabularyItemEntity> pool;
+
+  /// Records each submitted review as (userVocabularyId, quality).
+  final List<(String, ReviewQuality)> submissions = [];
+
+  _FakeQuizRepository({
+    required this.due,
+    required this.items,
+    required this.pool,
+  });
+
+  @override
+  Future<Either<Failure, List<UserVocabularyEntity>>> getDueVocabulary({
+    int limit = 20,
+  }) async =>
+      Right(due);
+
+  @override
+  Future<Either<Failure, VocabularyItemEntity>> getVocabularyItem(
+    String vocabularyId,
+  ) async {
+    final item = items[vocabularyId];
+    return item == null
+        ? const Left(NotFoundFailure())
+        : Right(item);
+  }
+
+  List<UserVocabularyEntity> deckItems = [];
+  List<UserVocabularyEntity> collection = [];
+  final List<String> addedToCollection = [];
+
+  @override
+  Future<Either<Failure, List<VocabularyItemEntity>>> getVocabularyItems({
+    String? courseId,
+    String? lessonId,
+    String? difficultyLevel,
+    String? tag,
+    String? search,
+    int limit = 50,
+    int offset = 0,
+  }) async =>
+      Right(pool);
+
+  @override
+  Future<Either<Failure, List<UserVocabularyEntity>>> getDeckItems(
+    String deckId,
+  ) async =>
+      Right(deckItems);
+
+  @override
+  Future<Either<Failure, List<UserVocabularyEntity>>> getUserCollection({
+    VocabularyStatus? status,
+    int limit = 50,
+    int offset = 0,
+  }) async =>
+      Right(collection);
+
+  @override
+  Future<Either<Failure, UserVocabularyEntity>> addToCollection(
+    String vocabularyId,
+  ) async {
+    addedToCollection.add(vocabularyId);
+    return Right(_userVocab('uv-$vocabularyId', vocabularyId));
+  }
+
+  @override
+  Future<Either<Failure, ReviewResultEntity>> submitReview(
+    String userVocabularyId,
+    ReviewQuality quality, {
+    int? timeSpentMs,
+  }) async {
+    submissions.add((userVocabularyId, quality));
+    return Right(
+      ReviewResultEntity(
+        userVocabularyId: userVocabularyId,
+        quality: quality,
+        xpEarned: 10,
+        newEaseFactor: 2.5,
+        newInterval: 3,
+        newRepetitions: 2,
+        nextReviewDate: DateTime.utc(2026, 6, 11),
+        reviewedAt: DateTime.utc(2026, 6, 8),
+      ),
+    );
+  }
+}
+
+QuizProvider _build(_FakeQuizRepository repo) => QuizProvider(
+      getDueVocabularyUseCase: GetDueVocabularyUseCase(repo),
+      submitReviewUseCase: SubmitReviewUseCase(repo),
+      vocabularyRepository: repo,
+    );
+
+void main() {
+  group('QuizProvider', () {
+    late _FakeQuizRepository repo;
+
+    setUp(() {
+      final w1 = _item('v1', 'serene', 'calm, peaceful, and untroubled');
+      final w2 = _item('v2', 'candid', 'truthful and straightforward');
+      final fillers = [
+        _item('v3', 'lucid', 'expressed clearly; easy to understand'),
+        _item('v4', 'frugal', 'sparing or economical with money'),
+        _item('v5', 'vivid', 'producing powerful, clear images'),
+      ];
+      repo = _FakeQuizRepository(
+        due: [_userVocab('uv1', 'v1'), _userVocab('uv2', 'v2')],
+        items: {'v1': w1, 'v2': w2},
+        pool: [w1, w2, ...fillers],
+      );
+    });
+
+    test('generates two-directional questions for each due word', () async {
+      final provider = _build(repo);
+      await provider.startQuizSession();
+
+      expect(provider.errorMessage, isNull);
+      // 2 words × 2 directions
+      expect(provider.totalQuestions, 4);
+
+      final directions = <QuizDirection>{};
+      final wordIds = <String>{};
+      while (provider.currentQuestion != null) {
+        final q = provider.currentQuestion!;
+        directions.add(q.direction);
+        wordIds.add(q.card.userVocabulary.id);
+        expect(q.options.length, greaterThanOrEqualTo(2));
+        expect(q.options.where((o) => o.isCorrect).length, 1);
+        provider.answer(q.correctIndex!);
+        provider.next();
+      }
+      await provider.finishPending();
+
+      expect(directions, {
+        QuizDirection.termToMeaning,
+        QuizDirection.meaningToTerm,
+      });
+      expect(wordIds, {'uv1', 'uv2'});
+      provider.dispose();
+    });
+
+    test('correct answers map a word to easy quality and award XP', () async {
+      final provider = _build(repo);
+      await provider.startQuizSession();
+
+      while (provider.currentQuestion != null) {
+        final correct = provider.currentQuestion!.correctIndex!;
+        provider.answer(correct);
+        provider.next();
+      }
+      await provider.finishPending();
+
+      // One review submitted per word, both fully correct → easy(4)
+      expect(repo.submissions.length, 2);
+      expect(
+        repo.submissions.map((s) => s.$2).toList(),
+        everyElement(ReviewQuality.easy),
+      );
+      expect(provider.totalXpEarned, 20);
+      expect(provider.wordsMastered, 2);
+      provider.dispose();
+    });
+
+    test('a partially-correct word maps to good quality', () async {
+      final provider = _build(repo);
+      await provider.startQuizSession();
+
+      var wrongedUv2 = false;
+      while (provider.currentQuestion != null) {
+        final q = provider.currentQuestion!;
+        final correct = q.correctIndex!;
+        final isUv2 = q.card.userVocabulary.id == 'uv2';
+        if (isUv2 && !wrongedUv2) {
+          wrongedUv2 = true;
+          provider.answer((correct + 1) % q.options.length); // wrong
+        } else {
+          provider.answer(correct);
+        }
+        provider.next();
+      }
+      await provider.finishPending();
+
+      final byWord = {for (final s in repo.submissions) s.$1: s.$2};
+      expect(byWord['uv1'], ReviewQuality.easy);
+      expect(byWord['uv2'], ReviewQuality.good);
+      expect(provider.wordsMastered, 1);
+      provider.dispose();
+    });
+
+    test('deck session builds a quiz from deck items', () async {
+      repo.deckItems = [_userVocab('uv1', 'v1'), _userVocab('uv2', 'v2')];
+      final provider = _build(repo);
+      await provider.startDeckSession(deckId: 'deck-1');
+
+      expect(provider.errorMessage, isNull);
+      expect(provider.totalQuestions, 4);
+      provider.dispose();
+    });
+
+    test('topic session adds uncollected words then quizzes them', () async {
+      // 'v1' already in collection; 'v2' must be added on the fly.
+      repo.collection = [_userVocab('uv1', 'v1')];
+      final provider = _build(repo);
+      await provider.startTopicSession(tag: 'general');
+
+      expect(provider.errorMessage, isNull);
+      expect(repo.addedToCollection, contains('v2'));
+      expect(provider.hasSession, isTrue);
+      provider.dispose();
+    });
+
+    test('surfaces an error when no words are due', () async {
+      final emptyRepo = _FakeQuizRepository(due: [], items: {}, pool: []);
+      final provider = _build(emptyRepo);
+      await provider.startQuizSession();
+
+      expect(provider.hasSession, isFalse);
+      expect(provider.errorMessage, isNotNull);
+      provider.dispose();
+    });
+  });
+}
diff --git a/flutter-app/test/smoke/vocab_and_lexi_offline_smoke_test.dart b/flutter-app/test/smoke/vocab_and_lexi_offline_smoke_test.dart
index 582e2d9d..8c009197 100644
--- a/flutter-app/test/smoke/vocab_and_lexi_offline_smoke_test.dart
+++ b/flutter-app/test/smoke/vocab_and_lexi_offline_smoke_test.dart
@@ -67,6 +67,7 @@ class _FakeLexiRepo implements LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
     String? idempotencyKey,
   }) async {
@@ -99,6 +100,7 @@ class _FakeLexiRepo implements LexiChatRepository {
     String? audioBase64,
     bool enableTts = true,
     String learnerLevel = 'B1',
+    String nativeLanguage = 'vi',
     String? storyContext,
   }) {
     return Stream.empty();
@@ -138,7 +140,10 @@ void main() {
         ],
       );
 
-      final provider = LexiChatProvider(repository: fakeRepo, aiClient: AiApiClient());
+      final provider = LexiChatProvider(
+        repository: fakeRepo,
+        aiClient: AiApiClient(),
+      );
       final summary = LexiSessionSummary(
         sessionId: 's-1',
         userId: 'smoke-user-1',
diff --git a/scripts/data-pipeline/translate_gemini.py b/scripts/data-pipeline/translate_gemini.py
index 2a7da180..33ec028a 100644
--- a/scripts/data-pipeline/translate_gemini.py
+++ b/scripts/data-pipeline/translate_gemini.py
@@ -1,16 +1,20 @@
 import json
+import os
 import time
 import requests
 import sys
 import random
 import re
 
-API_KEYS = [
-    "AIzaSyA7KgjM3Jt3E09RudKLUcA6e0WO4YOW2vY",
-    "AIzaSyCiKyxQERiVTEmlwa4euWOlQdlFo6UKLSo",
-    "AIzaSyBGjPwt7QLrZz4NgLUHnRts1E12yJEVgNQ",
-    "AIzaSyB_tii-C0tZEr4yEIsiCCtQQ_kx1o-SJLw"
-]
+def _load_api_keys():
+    raw_keys = os.getenv("GEMINI_API_KEYS") or os.getenv("GEMINI_API_KEY", "")
+    keys = [key.strip() for key in raw_keys.split(",") if key.strip()]
+    if not keys:
+        raise RuntimeError("Set GEMINI_API_KEYS or GEMINI_API_KEY before running translation")
+    return keys
+
+
+API_KEYS = _load_api_keys()
 
 FILE_PATH = "/opt/lexilingo/scripts/categorized_words_final.json"
 
diff --git a/scripts/data-pipeline/translate_missing_gemini.py b/scripts/data-pipeline/translate_missing_gemini.py
index 44c70e06..9f445cf0 100644
--- a/scripts/data-pipeline/translate_missing_gemini.py
+++ b/scripts/data-pipeline/translate_missing_gemini.py
@@ -5,7 +5,10 @@
 import os
 from aiohttp import ClientSession
 
-API_KEY = "AIzaSyA7KgjM3Jt3E09RudKLUcA6e0WO4YOW2vY"
+API_KEY = os.getenv("GEMINI_API_KEY", "").strip()
+if not API_KEY:
+    raise RuntimeError("Set GEMINI_API_KEY before running translation")
+
 FILE_PATH = "/opt/lexilingo/scripts/categorized_words_final.json"
 
 with open(FILE_PATH, "r", encoding="utf-8") as f:
@@ -13,4 +16,3 @@
 
 missing = [item for item in data if item.get("definition") == "#N/A yet" or not item.get("definition")]
 print(f"Found {len(missing)} items missing definitions.")
-