<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style>
body{text-align: center;}
.nav{width: 165px;}
.nav li{width:50px;height: 30px;float: left;list-style: none;margin-left: 5px;}
.nav li a{width:50px;height: 30px;background-color: #ffff00;display: block;}
.box{width: 200px;height: 200px;overflow: hidden;}
.box li{width: 200px;height: 200px;float: left;background-color: #008000;list-style: none;}
.box li:nth-child(2){background-color: #0000ff;}
</style>
</head>
<body>
<ul class="nav">
<li><a href="#box1">1</a></li>
<li><a href="#box2">2</a></li>
<li><a href="#box3">3</a></li>
</ul>
<ul class="box">
<li id="box1">1</li>
<li id="box2">2</li>
<li id="box3">3</li>
</ul>
</body>
</html>
