.focus{
    width:100%;
    height:320px;
    overflow:hidden;
    position:relative;
    background: url(/resources/images/index_banner1.jpg) center top / 100% no-repeat;
}
.focus ul{height:380px;position:absolute;}
.focus ul li{float:left;width:1200px;height:280px;overflow:hidden;position:relative;background:#000;}
.focus ul li div{position:absolute;overflow:hidden;}
.focus ul li img{display: inline-block;
    height: auto;
    max-width: 100%;}
.focus .btn{position:absolute;width:1200px;padding:5px 10px;right:0;bottom:5px;text-align:center;}
.focus .btn span{display:inline-block;_display:inline;_zoom:1;width:13px;height:13px;_font-size:0;margin-left:5px;cursor:pointer;background:#fff;border-radius:50%;}
.focus .btn span.on{background:yellow;}
.focus .preNext{width:45px;height:100px;position:absolute;top:90px;background:url(img/sprite.png) no-repeat 0 0;cursor:pointer;display:none;}
.focus .pre{left:0;}
.focus .next{right:0;background-position:right top;}