console 命令行工具 X clear
console
<!DOCTYPE html>
<html>
 
<head>
    <meta charset="utf-8">
    <title>Layout</title>
    <style media="screen">
        html * {
            padding: 0;
            margin: 0;
        }
        .layout article div {
            min-height: 150px;
            color: #ffffff;
        }
        .layout.float .left {
            float: left;
            width: 300px;
            background: red;
        }
 
        .layout.float .center {
            background: yellow;
            color: #000000;
        }
 
        .layout.float .right {
            float: right;
            width: 300px;
            background: blue;
        }
    </style>
</head>
<body>
    <!--浮动布局  -->
    <section class="layout float">
        <h1>三栏布局</h1>
        <article class="left-right-center">
            <div class="left">left</div>
            <div class="right">right</div>
            <div class="center">
                center
            </div>
        </article>
    </section>
</body>
</html>