css去浮動代碼經典版

.clearfix {
    *zoom:1;
}
.clearfix:before {
    content: ".";
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;
}
.clearfix:after {
    content: ".";
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;
}