Soft Grid CSS Framework is a 12 column grid system.

        <div class="container">
            <div class="row">
                <div class="one colon">.one.colon</div>
                <div class="eleven colon">.eleven.colon</div>
            </div>
    
            <div class="row">
                <div class="two colon">.one.colon</div>
                <div class="ten colon">.ten.colon</div>
            </div>
    
            <div class="row">
                <div class="three colon">.three.colon</div>
                <div class="nine colon">.nine.colon</div>
            </div>
        </div>

Demo: http://baransomakli.com/demo/softgridfw/