#downloadb{width:1280px;height:121px;position:absolute;top:70px;left:50%;margin-left:-950px;z-index:1500;}

/*下载*/


#downloadab .btn_downa{float:left;width:254px;height:268px;;position:relative;text-indent:-9999em;background:url(btn-1.png) no-repeat left bottom;display:block;}



#downloadc{width:1280px;height:121px;position:absolute;top:25px;left:50%;margin-left:610px;z-index:1500;}

/*下载*/


#downloadac .btn_downa{float:left;width:400px;height:400px;;position:relative;text-indent:-9999em;background:url(2.gif) no-repeat left bottom;display:block;}