.nav_box{width:100%;height:77px;background:url(../images/nav_box.jpg) repeat-x bottom;}.nav_box .nav{width:1003px;height:77px;margin:0 auto;}.nav_box .nav ul{width:1003px;height:77px;background:url(../images/nav_li_bg.jpg) no-repeat -3px bottom;z-index:50;}.nav_box .nav ul li{position:relative;float:left;width:143px;height:77px;background:url(../images/nav_li_bg.jpg) no-repeat bottom right;z-index:50;}.nav_box .nav ul li a{display:block;width:140px;height:77px;margin:0 auto;font-size:17px;color:#fff;text-align:center;z-index:50;}.nav_box .nav ul li a span{display:block;height:67px;line-height:67px;padding-top:10px;}.nav_box .nav ul li a:hover{background:url(../images/nav_hover.jpg) no-repeat right;height:77px;width:140px;z-index:50;}.nav_box .nav ul li ul{width:120px;height:auto;display:none;position:absolute;top:77px;left:1px;background-image:none;z-index:50;}.nav_box .nav ul li ul li{width:120px;height:36px;background:url(../images/nav_li.jpg) no-repeat bottom;z-index:50;}.nav_box .nav ul li ul li a{height:35px;display:block;background:url(../images/nav_sub_a.jpg) no-repeat left center;text-align:left;padding-left:28px;width:92px;z-index:50;line-height:35px;font-size:14px;color:#fff;}.nav_box .nav ul li ul li a:hover{height:35px;background:url(../images/nav_a_hover.jpg) no-repeat left center;width:92px;padding-left:28px;line-height:35px;z-index:50;}.nav_box .nav ul li ul .nav_sub_li{background:url(../images/nav_sub_li.jpg) no-repeat;width:120px;height:16px;border:none;z-index:50;}.ppp{background:url(../images/nav_hover.jpg) no-repeat right;}