.top_nav{ background-color:#fff; height:62px;}
 .bannerbox {width:100%;position:relative;overflow:hidden;height:1872px;}
.banner {width:3000px;position:absolute;left:50%;margin-left:-1500px;}

.about_nav{ float:left; width:190px; background-color:#fff; border:1px solid #bebebe; border-radius:3px;}
.about_nav li{ padding:20px 4px; text-align:center; border-bottom:1px solid #e9e9e9; font-size:16px; color:#555; cursor: pointer;}
.about_nav li.on{ background-color:#FF6161; color:#fff;}
.about_nav li:hover{color:#fff; background-color:#EC3C3C;}
.about_main{ float:right;background-color:#fff;border:1px solid #bebebe;border-radius:3px; width:800px; padding:30px;}