<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>上下垂直居中 在线演示 DIVCSS5</title>
<style>
.Absolute-Center {
margin: auto;
position: absolute;
top: 0; left: 0; bottom: 0; right: 0;
width:400px;height:200px;border:1px solid #00F;
}
</style>
<body>
<div class="Absolute-Center">DIV水平居中和上下垂直居中</div>
</body>
</html>
原文：http://www.cnblogs.com/meidik/p/5859024.html