style.css

/* The Falling Grid — product-grade UI */

:root {
    --bg: #000000;
    --bg-elevated: #0c0c0e;
    --surface: #141416;
    --surface-raised: #1c1c1f;
    --surface-hover: #242428;
    --border: rgba(255, 255, 255, 0.08);
    --border-strong: rgba(255, 255, 255, 0.14);
    --text: #ffffff;
    --text-secondary: #a1a1aa;
    --text-tertiary: #71717a;
    --accent: #0a84ff;
    --accent-hover: #409cff;
    --accent-muted: rgba(10, 132, 255, 0.18);
    --accent-glow: rgba(10, 132, 255, 0.35);
    --danger: #ff453a;
    --warning: #ff9f0a;
    --success: #30d158;
    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-xl: 24px;
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, sans-serif;
    --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
    --ease-spring: cubic-bezier(0.34, 1.2, 0.64, 1);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.55);
    --shadow-board: 0 20px 50px rgba(0, 0, 0, 0.5), inset 0 1px 0 rgba(255, 255, 255, 0.04);
    --coral: #ff6b6b;
    --sky: #5ac8fa;
    --amber: #ffd60a;
    --violet: #bf5af2;
    --mint: #63e6a8;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    min-height: 100dvh;
    min-height: 100svh;
    font-size: 15px;
    line-height: 1.47;
    letter-spacing: -0.01em;
    overflow-x: hidden;
    overscroll-behavior: none;
}

body.modal-open {
    overflow: hidden;
}

.noscript {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    text-align: center;
    background: var(--bg);
    color: var(--text-secondary);
}

button {
    font: inherit;
    cursor: pointer;
    border: none;
    background: none;
    color: inherit;
    -webkit-tap-highlight-color: transparent;
}

button:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.hidden { display: none !important; }

/* —— Ambient background —— */
.page-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(10, 132, 255, 0.12), transparent 55%),
        radial-gradient(ellipse 60% 40% at 100% 100%, rgba(191, 90, 242, 0.06), transparent 50%),
        var(--bg);
    pointer-events: none;
}

/* —— App shell —— */
.app {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: min(440px, 100%);
    margin: 0 auto;
    padding:
        max(var(--space-3), env(safe-area-inset-top))
        max(var(--space-4), env(safe-area-inset-right))
        max(var(--space-5), env(safe-area-inset-bottom))
        max(var(--space-4), env(safe-area-inset-left));
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    min-height: 100dvh;
    min-height: 100svh;
    user-select: none;
    -webkit-user-select: none;
    animation: app-enter 0.5s var(--ease) backwards;
}

@keyframes app-enter {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* —— Header (iOS app bar) —— */
.header {
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    gap: var(--space-3) var(--space-4);
    align-items: center;
    padding-bottom: var(--space-2);
}

.header__brand {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    grid-column: 1;
}

.header__mark {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(145deg, var(--surface-raised) 0%, var(--surface) 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--accent);
    box-shadow: var(--shadow-sm);
}

.header__brand h1 {
    font-size: 1.0625rem;
    font-weight: 600;
    letter-spacing: -0.025em;
    line-height: 1.2;
}

.header__brand span {
    display: block;
    margin-top: 2px;
    font-size: 0.6875rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    color: var(--text-tertiary);
}

.header__scores {
    grid-column: 1;
    display: flex;
    gap: var(--space-6);
}

.score-block .label {
    display: block;
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--text-tertiary);
    margin-bottom: 2px;
}

.score-block .value {
    font-size: 1.25rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.03em;
}

.score-block--dim .value {
    color: var(--text-secondary);
    font-weight: 500;
}

.score-block--pulse .value {
    animation: score-pop 0.45s var(--ease-spring);
}

.score-block--highlight .value {
    color: var(--accent);
}

@keyframes score-pop {
    0% { transform: scale(1); }
    40% { transform: scale(1.12); }
    100% { transform: scale(1); }
}

.header__actions {
    grid-column: 2;
    grid-row: 1 / 3;
    display: flex;
    gap: var(--space-2);
    align-self: start;
}

.icon-btn {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    transition: background 0.2s var(--ease), color 0.2s var(--ease), transform 0.15s var(--ease), border-color 0.2s var(--ease);
}

.icon-btn:hover {
    background: var(--surface-hover);
    color: var(--text);
    border-color: var(--border-strong);
}

.icon-btn:active {
    transform: scale(0.94);
}

.icon-btn[aria-pressed="true"] {
    background: var(--accent-muted);
    border-color: rgba(10, 132, 255, 0.35);
    color: var(--accent);
}

.icon-btn__glyph {
    display: block;
}

/* —— Metrics —— */
.metrics {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3);
}

.metric {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    box-shadow: var(--shadow-sm);
    transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.metric--hero {
    grid-column: 1 / -1;
    padding: var(--space-5) var(--space-4);
    background: linear-gradient(180deg, var(--surface-raised) 0%, var(--surface) 100%);
}

.metric--compact {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    min-height: 88px;
}

.metric--level { grid-column: span 1; }

.metric--urgent {
    border-color: rgba(255, 159, 10, 0.35);
    box-shadow: 0 0 0 1px rgba(255, 159, 10, 0.12);
}

.metric--hero.metric--urgent .metric__hero-value {
    color: var(--warning);
}

#shift-metric.metric--urgent .metric__value {
    color: var(--warning);
}

.metric__row {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    width: 100%;
    margin-bottom: var(--space-3);
}

.metric .label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-tertiary);
}

.metric .label strong {
    color: var(--text);
    font-weight: 600;
}

.metric__hero-value {
    font-size: 2rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.04em;
    line-height: 1;
    color: var(--text);
}

.metric__value {
    font-size: 1.5rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.03em;
    margin-top: var(--space-1);
}

.metric__sub {
    display: flex;
    margin-top: auto;
    padding-top: var(--space-2);
    color: var(--text-secondary);
}

.level-xp {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
}

.level-bonus {
    display: block;
    margin-top: var(--space-2);
    font-size: 0.6875rem;
    color: var(--text-tertiary);
}

.bar {
    height: 6px;
    background: rgba(255, 255, 255, 0.06);
    border-radius: 99px;
    overflow: hidden;
}

.bar--hero { height: 8px; }

.bar--thin {
    height: 4px;
    width: 100%;
    margin-top: var(--space-2);
}

.bar__fill {
    height: 100%;
    width: 100%;
    background: var(--text);
    border-radius: 99px;
    transition: width 0.15s linear, background 0.25s var(--ease);
}

.bar__fill--accent {
    background: linear-gradient(90deg, var(--accent) 0%, #5ac8fa 100%);
}

/* —— Board —— */
.board-wrap {
    position: relative;
    width: min(100%, min(70dvh, 500px));
    aspect-ratio: 1;
    margin: 0 auto;
    padding: var(--space-3);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-board);
    transition: border-color 0.4s var(--ease), box-shadow 0.4s var(--ease);
}

.board-wrap.freeze-active {
    border-color: rgba(10, 132, 255, 0.5);
    box-shadow: var(--shadow-board), 0 0 0 3px var(--accent-muted);
}

.board-wrap.shift-warning {
    border-color: rgba(255, 159, 10, 0.45);
    animation: shift-pulse 2s var(--ease) infinite;
}

@keyframes shift-pulse {
    0%, 100% { box-shadow: var(--shadow-board); }
    50% { box-shadow: var(--shadow-board), 0 0 0 3px rgba(255, 159, 10, 0.15); }
}

#particle-canvas {
    position: absolute;
    inset: var(--space-3);
    width: calc(100% - var(--space-6));
    height: calc(100% - var(--space-6));
    pointer-events: none;
    z-index: 2;
    border-radius: var(--radius-md);
}

.board-grid {
    position: relative;
    z-index: 1;
    width: 100%;
    height: 100%;
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    grid-template-rows: repeat(8, 1fr);
    gap: 5px;
    padding: 6px;
    background: #08080a;
    border-radius: var(--radius-md);
    transform-origin: center center;
    transition: transform 0.55s var(--ease-spring);
}

.cell {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 6px;
    transition: background 0.12s var(--ease), box-shadow 0.12s var(--ease);
}

.cell.hover-valid {
    background: var(--accent-muted);
    box-shadow: inset 0 0 0 1.5px rgba(10, 132, 255, 0.5);
}

.cell.hover-invalid {
    background: rgba(255, 69, 58, 0.12);
    box-shadow: inset 0 0 0 1.5px rgba(255, 69, 58, 0.35);
}

.block-element {
    border-radius: 6px;
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.28),
        0 2px 4px rgba(0, 0, 0, 0.25);
    animation: block-settle 0.35s var(--ease-spring) backwards;
}

.block-element.falling {
    animation: block-fall 0.26s var(--ease) forwards;
}

@keyframes block-fall {
    from { transform: translateY(-6px); opacity: 0.85; }
    to { transform: translateY(0); opacity: 1; }
}

@keyframes block-settle {
    from { opacity: 0; transform: scale(0.88); }
    to { opacity: 1; transform: scale(1); }
}

.cell[data-color="coral"], .color-coral {
    background: linear-gradient(165deg, #ff8585 0%, var(--coral) 100%) !important;
}
.cell[data-color="sky"], .color-sky {
    background: linear-gradient(165deg, #7dd3fc 0%, var(--sky) 100%) !important;
}
.cell[data-color="amber"], .color-amber {
    background: linear-gradient(165deg, #ffe566 0%, var(--amber) 100%) !important;
}
.cell[data-color="violet"], .color-violet {
    background: linear-gradient(165deg, #d4a5ff 0%, var(--violet) 100%) !important;
}
.cell[data-color="mint"], .color-mint {
    background: linear-gradient(165deg, #86efac 0%, var(--mint) 100%) !important;
}

.rotate-cw { transform: rotate(90deg) !important; }
.rotate-ccw { transform: rotate(-90deg) !important; }

/* —— Tray —— */
.tray {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-4);
    box-shadow: var(--shadow-sm);
}

.tray__meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    margin-bottom: var(--space-3);
}

.tray__cost {
    font-weight: 500;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
}

.pieces-shelf {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-3);
    min-height: 76px;
    margin-bottom: var(--space-4);
}

.draggable-piece-container {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: grab;
    touch-action: none;
    transition: border-color 0.2s var(--ease), transform 0.25s var(--ease), opacity 0.25s var(--ease), background 0.2s var(--ease);
}

.draggable-piece-container:hover:not(.placed):not(.empty-slot) {
    border-color: var(--border-strong);
    background: var(--surface-raised);
}

.draggable-piece-container:active:not(.placed) {
    cursor: grabbing;
    transform: scale(0.98);
}

.draggable-piece-container.is-dragging {
    opacity: 0.35;
}

.draggable-piece-container.placed {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.85);
}

.draggable-piece-container.empty-slot {
    opacity: 0.35;
    border-style: dashed;
    border-color: rgba(255, 255, 255, 0.06);
    pointer-events: none;
}

.piece-grid {
    display: grid;
    gap: 2px;
    transform: scale(0.52);
    transform-origin: center;
    pointer-events: none;
}

.floating-drag-piece {
    position: fixed;
    z-index: 500;
    pointer-events: none;
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.55));
}

.floating-drag-piece .piece-grid {
    transform: scale(1);
    gap: 3px;
}

.tray__tools {
    display: grid;
    grid-template-columns: 1.15fr 1fr 1fr;
    gap: var(--space-2);
    align-items: end;
}

.hold {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.hold-slot {
    height: 48px;
    background: var(--bg-elevated);
    border: 1.5px dashed var(--border-strong);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.chip {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 12px 10px;
    border-radius: var(--radius-sm);
    background: var(--surface-raised);
    border: 1px solid var(--border);
    font-size: 0.8125rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text);
    transition: background 0.2s var(--ease), transform 0.15s var(--ease), opacity 0.2s var(--ease);
}

.chip__cost {
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--text-tertiary);
}

.chip:hover:not(:disabled) {
    background: var(--surface-hover);
}

.chip:active:not(:disabled) {
    transform: scale(0.97);
}

.chip:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.streak-line {
    text-align: center;
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    padding-top: var(--space-1);
}

.streak-line strong {
    color: var(--text-secondary);
    font-weight: 600;
}

.game-footer {
    margin-top: auto;
    padding-top: var(--space-2);
    text-align: center;
}

.game-footer p {
    font-size: 0.6875rem;
    color: var(--text-tertiary);
    letter-spacing: 0.02em;
}

.badge-new-best {
    display: inline-block;
    margin: var(--space-2) 0 var(--space-3);
    padding: 6px 12px;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--success);
    background: rgba(48, 209, 88, 0.12);
    border: 1px solid rgba(48, 209, 88, 0.25);
    border-radius: 99px;
}

.result-card--best {
    border-color: rgba(48, 209, 88, 0.35);
    background: rgba(48, 209, 88, 0.08);
}

/* —— Buttons —— */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 24px;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    transition: background 0.2s var(--ease), transform 0.15s var(--ease), box-shadow 0.2s var(--ease);
}

.btn--primary {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 4px 14px var(--accent-glow);
}

.btn--primary:hover {
    background: var(--accent-hover);
}

.btn--primary:active {
    transform: scale(0.98);
}

.btn--block {
    display: flex;
    width: 100%;
}

/* —— Event popup —— */
.event-popup {
    position: fixed;
    inset: 0;
    z-index: 150;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-6);
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s var(--ease);
}

.event-popup.visible {
    opacity: 1;
    pointer-events: auto;
}

.event-popup__card {
    width: 100%;
    max-width: 320px;
    padding: var(--space-6) var(--space-5);
    text-align: center;
    background: var(--surface-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    transform: scale(0.92) translateY(8px);
    transition: transform 0.4s var(--ease-spring);
}

.event-popup.visible .event-popup__card {
    transform: scale(1) translateY(0);
}

.event-popup__icon {
    width: 56px;
    height: 56px;
    margin: 0 auto var(--space-4);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    background: var(--accent-muted);
    border-radius: 50%;
    color: var(--accent);
}

.event-popup__card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-2);
}

.event-popup__card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.event-popup__bonus {
    margin-top: var(--space-3);
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent);
}

.event-popup--shift .event-popup__icon { background: rgba(255, 159, 10, 0.15); color: var(--warning); }
.event-popup--chroma .event-popup__icon { background: rgba(191, 90, 242, 0.15); color: var(--violet); }
.event-popup--level .event-popup__icon { background: var(--accent-muted); color: var(--accent); }
.event-popup--combo .event-popup__icon { background: rgba(48, 209, 88, 0.15); color: var(--success); }
.event-popup--match .event-popup__icon { background: var(--accent-muted); color: var(--accent); }

.event-popup .btn--primary {
    margin-top: var(--space-5);
    width: 100%;
}

/* —— Modals (sheet style) —— */
.modal {
    position: fixed;
    inset: 0;
    z-index: 200;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.35s var(--ease);
}

@media (min-width: 600px) {
    .modal {
        align-items: center;
        padding: var(--space-6);
    }
}

.modal.active {
    opacity: 1;
    pointer-events: auto;
}

.modal__sheet {
    width: 100%;
    max-width: 400px;
    max-height: 92dvh;
    overflow-y: auto;
    padding: var(--space-4) var(--space-5) max(var(--space-6), env(safe-area-inset-bottom));
    background: var(--surface-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    box-shadow: var(--shadow-lg);
    transform: translateY(100%);
    transition: transform 0.45s var(--ease-spring);
}

.modal.active .modal__sheet {
    transform: translateY(0);
}

@media (min-width: 600px) {
    .modal__sheet {
        border-radius: var(--radius-xl);
        transform: scale(0.94) translateY(12px);
    }

    .modal.active .modal__sheet {
        transform: scale(1) translateY(0);
    }
}

.modal__sheet--compact {
    padding-top: var(--space-6);
    text-align: center;
}

.modal__handle {
    width: 36px;
    height: 5px;
    margin: 0 auto var(--space-4);
    background: rgba(255, 255, 255, 0.2);
    border-radius: 99px;
}

@media (min-width: 600px) {
    .modal__handle { display: none; }
}

.modal__hero {
    text-align: center;
    margin-bottom: var(--space-6);
}

.modal__logo {
    width: 72px;
    height: 72px;
    margin: 0 auto var(--space-4);
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(145deg, var(--accent-muted) 0%, transparent 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    color: var(--accent);
}

.modal__hero h2,
.modal__title-center {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.15;
}

.modal__title-center {
    margin-bottom: var(--space-2);
}

.modal__tagline {
    margin-top: var(--space-2);
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.5;
    max-width: 280px;
    margin-left: auto;
    margin-right: auto;
}

.modal__subtitle {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: var(--space-6);
}

.modal__reason {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin: var(--space-2) 0 var(--space-5);
    line-height: 1.5;
}

.rules {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    margin-bottom: var(--space-6);
}

.rule {
    padding: var(--space-4);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    text-align: left;
    transition: border-color 0.2s var(--ease);
}

.rule:hover {
    border-color: var(--border-strong);
}

.rule__title {
    font-size: 0.8125rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text);
    margin-bottom: var(--space-1);
}

.rule__text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.45;
}

.results {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-3);
    margin-bottom: var(--space-6);
}

.result-card {
    padding: var(--space-4) var(--space-3);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
}

.result-card span {
    display: block;
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--text-tertiary);
    margin-bottom: var(--space-1);
}

.result-card strong {
    font-size: 1.25rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.03em;
}

.shake-animation {
    animation: shake 0.35s ease-in-out infinite;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    50% { transform: translateX(2px); }
}

/* —— Responsive —— */
@media (max-width: 380px) {
    .header__scores { gap: var(--space-4); }
    .score-block .value { font-size: 1.125rem; }
    .metric__hero-value { font-size: 1.75rem; }
    .metrics { grid-template-columns: 1fr; }
    .metric--compact { min-height: auto; flex-direction: row; flex-wrap: wrap; align-items: center; gap: var(--space-2); }
    .metric__sub { margin-top: 0; padding-top: 0; margin-left: auto; }
    .tray__tools { grid-template-columns: 1fr 1fr; }
    .hold {
        grid-column: 1 / -1;
        display: grid;
        grid-template-columns: 1fr auto;
        gap: var(--space-2);
        align-items: center;
    }
    .hold-slot { height: 52px; }
    .hold .chip { align-self: stretch; }
    .results { grid-template-columns: 1fr; }
}

@media (max-height: 520px) and (orientation: landscape) {
    body { overflow-y: auto; }
    .app { min-height: auto; gap: var(--space-2); padding-top: var(--space-2); }
    .board-wrap { width: min(100%, min(44dvh, 300px)); }
    .pieces-shelf { min-height: 56px; }
    .draggable-piece-container { min-height: 52px; }
    .modal__sheet { max-height: 94vh; }
}

@media (min-width: 600px) {
    .app {
        max-width: 480px;
        gap: var(--space-5);
        padding-left: var(--space-6);
        padding-right: var(--space-6);
    }

    .header {
        grid-template-columns: 1fr auto auto;
        grid-template-rows: auto;
        align-items: center;
    }

    .header__brand { grid-column: 1; }
    .header__scores { grid-column: 2; justify-content: flex-end; }
    .header__actions { grid-column: 3; grid-row: 1; }

    .metrics {
        grid-template-columns: 1.4fr 0.8fr 0.8fr;
        grid-template-rows: auto;
    }

    .metric--hero { grid-column: 1; grid-row: 1; }
    .metrics .metric--compact:nth-child(2) { grid-column: 2; }
    .metric--level { grid-column: 3; }

    .board-wrap { width: min(100%, min(58dvh, 520px)); }
}

@media (min-width: 1024px) {
    .app { max-width: 500px; }

    .page-bg {
        background:
            radial-gradient(ellipse 50% 40% at 15% 0%, rgba(10, 132, 255, 0.1), transparent 50%),
            radial-gradient(ellipse 40% 35% at 85% 100%, rgba(191, 90, 242, 0.06), transparent 50%),
            var(--bg);
    }
}

@media (hover: none) and (pointer: coarse) {
    .icon-btn { width: 44px; height: 44px; }
    .chip { min-height: 48px; }
    .btn--primary { min-height: 52px; }
    .draggable-piece-container { min-height: 76px; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}