为什么这个foot显示不出来呢
<!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:100%; height:100px; background-color:#999;}
.main{height:600px;background-color:red;}
.left{width:30%; height:600px; background-color:blue; float:left; }
.right{width:65%; height:600px; background-color:green; float:right; }}
.foot{width:100%; height:50px; background-color:#000; overflow:hidden; clear:both;}
</style>
</head>
<body>
<div class="top">top</div>
<div class="main">
<div class="right">right</div>
<div class="left">left</div>
</div>
<div class="foot">foot</div>
