css高度塌陷
<style>
/*.clear{clear:both;}*/
.per{
width: 300px;
height: auto;
border:2px solid #aaa;
/*overflow:hidden;
zoom:1;*/
}
.li{
width: 100px;
height: 100px;
background: red;
margin: 5px;
float: left;
}
.cleared:after{
content:".";
display:block;
height:0;
visibility:hidden;
clear:both;
}
.cleared{
zoom:1;
}
/*此处写代码*/
</style>
</head>
<body>
<div class="per cleared">
<div class="li"></div>
<div class="li"></div>
<div class="clear"></div>
<!-- 此处写代码 -->
</div>
