<!DOCTYPE PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "w3.org/TR/x1/DTD/x1-transitional.dtd">
< xmlns"w3.org/1999/x">
<head>
<meta http-equiv"Content-Type" content"text/; charsetutf-8" />
<title>无标题文档</title>
<style>
*{margin:0; padding:0;}
.box{width:1200px; background:555; height:600px; margin:0px auto; }
</style>
</head>
<body>
<div class"box">
</div>
</body>
</>