<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<title> 左右浮动</title>
<style type="text/css">
#nav{height:30px;border:1px solid red;}
#content{border:1px solid black;}
#footer{position:absolute;bottom:0px;height: 20px;border:1px solid red; 100%;}
</style>
</head>
<body>
<div id="nav">sdfs</div>
<div id="content">
<div style="border:1px solid red;float:left;300px;height:300px;">sdfsd</div>
<div style="border:1px solid red;float:right;400px;height:300px;">sdfs</div>
<span style="clear:both"></span>
</div>
<div id="footer">sdflksdjflskdjflksdjflskdjflksjdlfjsldkfjld</div>
</body>
</html>
样式：
