CSS Sticky Footer

HTML

<div id="wrap">
    <div id="main" class="clearfix">
        <div id="content">
        </div>
        <div id="side">
        </div>
    </div>
</div>
<div id="footer">
</div>

CSS

.clearfix:after {content: ".";
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;}
.clearfix {display: inline-block;}
/* Hides from IE-mac \*/
* html .clearfix { height: 1%;}
.clearfix {display: block;}
/* End hide from IE-mac */
html, body, #wrap {height: 100%;}
body > #wrap {height: auto; min-height: 100%;}
#main {padding-bottom: 150px;}  /* 必须使用和footer相同的高度 */
#footer {position: relative;
    margin-top: -150px; /* footer高度的负值 */
    height: 150px;
    clear:both;}