这种布局有以下几个难点：
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
.main,.sitebar {
height: 300px;
font: bolder 20px/300px ‘微软雅黑‘;
color: #fff;
text-align: center;
}
.main {
width: 100%;
float: left;
}
.main .content {
margin-left: 200px;
background-color: red;
}
.sitebar {
width: 200px;
float: left;
margin-left: -100%;
background-color: green;
}
</style>
</head>
<body>
<div class="main">
<div class="content">右侧主体自适应区块</div>
</div>
<div class="sitebar">左侧定宽200px区块</div>
</body>
</html>
原文：http://www.cnblogs.com/lishuaihaoqiang/p/4979715.html