CSS实现响应式布局(自动拆分几列)

<style type="text/css">


        .container{
            margin-top: 10px;
        }

        .outerDiv{
            float:left;
            width:100%;
        }

        /* 大于648像素一行两个div，innerDiv两个宽度为：(300+4+20)*2 */
        @media screen and (min-width: 648px){
            .outerDiv {
                width: 50%
            }
        }

        .innerDiv{
            min-width: 300px;
            height: 80px;
            border-radius: 10px;
            border: 2px solid #4a403f;
            margin: 2px 10px;
            background-color: #99ccff;
            color:#beb2b2;
            font-family: Arial;
            font-size:18px;
        }


    </style>

<div class="container">

    <div class="outerDiv">
        <div class="innerDiv">

        </div>
    </div>

    <div class="outerDiv">
        <div class="innerDiv">

        </div>
    </div>

    <div class="outerDiv">
        <div class="innerDiv">

        </div>
    </div>

    <div class="outerDiv">
        <div class="innerDiv">

        </div>
    </div>

    <!-- 清除浮动 -->
    <div style="clear: both"></div>
</div>