<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
*{ margin:0; padding:0;}
body{ font-family:微软雅黑; text-align:center;}
a{ color:#f60; text-decoration:none;}
hgroup{ margin-bottom:10px;}
nav{ height:48px; background:#ff6600;}
nav li{ float:left; background:#000; border-radius:5px; padding:5px 10px; margin:10px; list-style:none;}
</style>
</head>
<body>
<header>
<hgroup>
<h1>HTML5</h1>
<a href="###">[手机版]</a>
<a href="###">[电脑版]</a>
</hgroup>
<nav>
<ul>
<li><a href="###">首页</a></li>
<li><a href="###">手机版</a></li>
<li><a href="###">电脑版</a></li>
</ul>
</nav>
</header>
</body>
</html>
效果图：