两列或多列等高布局实现

<div class="mian">
<div class="left">左列</div>
<div class="middle">中列</div>
<div class="right">右列</div>
</div>
.mian {
width: 1360px;
overflow: hidden;
}
.mian .left,
.mian .right,
.mian .middle {
float: left;
padding-bottom: 9000px;
margin-bottom: -9000px;
}
.mian .left {
width: 180px;
height: 280px;
background-color: red;
}
.mian .middle {
margin-left: 10px;
background-color: blue;
}
.mian .right {
margin-left: 10px;
background-color: silver;
}