<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
.left,.right,.main{height: 400px;}
.left{width: 30%;background: red;position: absolute;top:0;left: 0;}
.main{margin:0 20%;background: pink;}
.right{width: 30%;background: blue;position:absolute;top:0;right: 0;}
</style>
</head>
<body>
<div>hhhhh</div>
<div>hhhhh</div>
<div>hhhhh</div>
</body>
</html>为啥还出现了覆盖？？？？？？
stone310