两栏布局

CSS

.right{
    position: absolute;
    right: 0px;
    width: 100px;
    height: 100px;
    background-color: #fcc;
    opacity: 0.5;
}
.left{
    margin-right: 100px;
    height: 100px;
    background-color: #123; 
}

HTML

<div class="right"></div>
<div class="left"></div>

两栏布局1.jpg

div出生顺序不能变

<div class="left"></div>
<div class="right"></div>

两栏布局2.jpg