.banner_box{width:100%;text-align:center;}
.banner_box img{vertical-align:middle;}
.roll_img_mb_01{overflow:hidden;position:relative;}
.roll_img_mb_01 .img_box{overflow:hidden;text-align:center;}
.roll_img_mb_01 .img_box img{vertical-align:middle;width:100%;}
.roll_img_mb_01 .nav_box{overflow:hidden;height:20px;position:absolute;right:10px;bottom:0px;}
.roll_img_mb_01 .nav_box li{width:10px;height:10px;font-size:1px;overflow:hidden;background:#ccc;border-radius:50px;float:left;margin:4px;}
.roll_img_mb_01 .nav_box .li_on{background:#C00;}