<body> <div class="left"></div> <div class="right"></div> </body>
html,body{
width: 100%;
height: 100%;
}
.left{
float:left;
width: 300px;
height: 100%;
background: red;
}
.right{
height: 100%;
background: blue;
}
html,body{
width: 100%;
height: 100%;
}
.left{
width: 300px;
position: absolute;
height: 100%;
background: red;
}
.right{
margin-left: 300px;
height: 100%;
background: blue;
}
原文：http://www.cnblogs.com/llauser/p/6832213.html