<!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>无标题文档</title>
<style type="text/css">
.div1{
border:1px solid red;
width:300px;
height:200px;
float:left;
margin-bottom:3px;}
.div2{
border:1px solid red;
width:300px;
height:300px;
float:left;
clear:both;
}
.div3{
position:relative;
top:-205px;
border:1px solid red;
width:550px;
height:505px;
float:left;
margin-left:5px;
}
</style>
</head>
<body>
<div class="div1"></div>
<div class="div2"></div>
<div class="div3"></div>
</body>
</html>
原文：http://www.cnblogs.com/jiangwenli/p/4924501.html