/* 清除浮动 */html body div.clear, html body span.clear {    background: none;    border: 0;    clear: both;    display: block;    float: none;    font-size: 0;    margin: 0;    padding: 0;    position: static;    overflow: hidden;    visibility: hidden;    width: 0;    height: 0;    line-height: 0;}.clearfix:after {    clear: both;    content: ".";    height: 0;    display: block;    overflow: hidden;    visibility: hidden;}.clearfix {    height: 1%;    display: inline-block; /* for IE/Mac */    zoom: 1; /* for ie6 & ie7 */}