利用浮动元素实现自适应布局

1.两侧固定，中间自适应

    <style>
        .left {
            float: left;
            width: 100px;
            height: 200px;
            background: red;
        }

        .right {
            float: right;
            width: 200px;
            height: 200px;
            background: blue;
        }

        .center {
            margin-left: 100px;
            margin-right: 200px;
            height: 300px;
            background: green;
        }
    </style>



    <div class="container">
        <div class="left"></div>
        <div class="right"></div>
        <div class="center"></div>
    </div>
</body>

2.左侧固定，右侧自适应

    <style>
        .left {
            float: left;
            width: 200px;
            height: 200px;
        background-color: red;
        }

        .right {
            height: 300px;
            background-color:lime;
            margin-left: 200px;
        }

    </style>


    <div class="container">
        <div class="left"></div>
        <div class="right"></div>
    </div>

3.右侧固定，左侧自适应

    <style>
        .left {
            height: 300px;
            background-color:lime;
            margin-right: 200px;
        }
        .right {
            float: right;
            width: 200px;
            height: 200px;
            background-color: red;
        }

    </style>



    <div class="container">
        <div class="right"></div>
        <div class="left"></div>
        
    </div>