width设置与不设置为什么效果不一样
<!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>混合布局编程挑战</title>
<style type="text/css">
body{ margin:0; padding:0; font-size:30px; color:#fff}
.top{width:80%; height:30px; margin:0 auto; background-color: silver;}
.main{width:80%; height:300px; margin:0 auto; position:relative; background-color: red;}
.left{width:190px; height:300px; position:absolute; left:0; top:0; background-color: blue;}
.right{width:100%; height:300px; margin:0 0 0 200px; background-color: green;}
.foot{width:80%; height:30px; margin:0 auto; background-color: orange;}
</style>
</head>
<body>
<div class="top">top</div>
<div class="main">
<div class="right">right</div>
<div class="left">left</div>
</div>
<div class="foot">foot</div>
</body>
</html>
天生我才必有用哈1回答
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Html/CSS