.top{width:100%;height:100px;background:#ccc;}

.main{width:100%;height:500px;background:red;}

.left{ width:200px;height:500px;background:blue;float:left;}

.right{margin:0 0 50px 210px;width:100%;height:500px;background:green;}

.foot{width:100%;height:50px;background:#369;}