背景层自适应高度
1
<div style=”overflow:hidden; _height:1%; border:1px#333 solid; width:600px; margin:auto;”>
<div style=”width:300px; float:left; height:100px; background:#f60;”></div>
<div style=”width:300px; float:left; height:300px; background:#ccc;”></div>
</div>
2
<div class=”m clear”>
<div>左</div>
<div>右</div>
</div>
.clear:after {
content: “.”;
display: block;
height: 0;
clear: both;
visibility: hidden;
}
关于after可以参考：http://www.blueidea.com/tech/web/2005/3065.asp