这题的 浮动 我改用了相对定位 看上去一样 新人 不知道是对是错
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>混合布局编程挑战</title>
<style type="text/css">
body{ margin:0; padding:0; font-size:30px; color:#fff}
.top{width:800px; height:200px; background: #ccc; margin:0 auto;}
.main{width:800px;height:600px; background: #cff; margin:0 auto;}
.left{width:200px; height:600px; background: #00f; float:left;}
.center{width:20px;height:600px; background: #f30; position:relative; left:180px;}
.right{width:600px; height:600px; background: #0c6;float:right;}
.foot{width:800px; height:100px; background: #f60; margin:0 auto;}
</style>
</head>
<body>
<div class="top">top</div>
<div class="main">
<div class="right">right</div>
<div class="left">
<div class="center"></div>
</div>
</div>
<div class="foot">foot</div>
</body>
</html>
