<html>
<head>
<style type="text/css">
* {margin:0; padding:0; list-style:none; }
.page { 100%; }
.left {200px; position:absolute; left:0 ;z-index:1; background-color:Red;}
.right {100%; position:absolute; left:0; background-color:Black; color:White;}
.content {margin-left:210px; }
</style>
</head>
<body>
<div class="page">
<div class="left">左侧
</div>
<div class="right">
<div class="content">
右侧
</div>
</div>
</div>
</body>
</html>