CSS 3栏自适应布局

绝对定位

css
        html,body{margin: 0px;height:100%;}
        div{height: 100%;}
        .left,.right {top: 0px;position: absolute;width: 200px;background-color: black;}
        .left {left: 0px;}
        .right {right: 0px;}
        .center {margin: 0px 200px;background-color: red;}
html
        <div class='left'></div>
        <div class="center"></div>
        <div class='right'></div>

浮动

css
        html,body{margin: 0px;padding: 0px;height:%;}
        div{height:%;}
        .left,.right {width: 200px;background-color: black;}
    　　 .left {float: left;}
        .right {float:right;}
    　　.center {margin: 0px 200px;background-color: red;}
html
        <div class='left'></div>
        <div class='right'></div>
        <div class="center"></div>