.footer_nav { width: 100%; position: fixed; z-index: 2000; bottom: 0; background: #fff; height: 50px;}
.footer_nav a { display: block; width: 20%; height: 50px; text-align: center;  float: left;}  
.footer_nav a img { margin-top: 5.5px;}
.footer_nav a span {color: #666;display: block;}
.active { background-color: inherit;}