<!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=gb2312" />
<title>无标题文档</title>
<style type="text/css">
<!--
html,body{
height:100%;
}
.box1 {
background-color: #0000FF;
height:100%;
position:relative;
}
.box2 {
background-color: #00FFFF;
height:90%;
width:90%;
left:5%;
top:5%;
position:absolute;
}
.box3 {
background-color: #FFFF00;
height:20%;
width:20%;
right:5%;
bottom:5%;
position:absolute;
}
-->
</style>
</head>
<body>
<div class="box1">
<div class="box2">
<div class="box3"></div>
</div>
</div>
</body>
</html>