<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
div{
height: 500px;
}
.left{
width: 200px;
background-color: red;
position: absolute;
left: 0;
top: 0;
}
.right{
width: 200px;
background-color: yellow;
position: absolute;
right: 0;
top: 0;
}
.center{
margin: 0 200px;
background-color: green;
}
</style>
</head>
<body>
<div class="center"></div>
<div class="left"></div>
<div class="right"></div>
</body>
</html>
原文：http://www.cnblogs.com/pan-hello/p/4562679.html