float引起层飘出父层的解决方法

1.加clear空div
.clearfix:after{
content:“.”;display:block;
height:0;
clear:both;
visibility:hidden;}
.clearfix{display:inline-block;}
/*HidesfromIE-mac*/
*html.clearfix{height:1%;}
.clearfix{display:block;}/*EndhidefromIE-mac*/
.clearfix{
display:block;
margin:0px;
clear:both;
padding:0px;
visibility:hidden;
background-color:#666666;
border:0pxnone#FFFFFF;
}
.clearfix:after{height:1px;}

使用方法：
在所有浮动层之后加上这个层