.dl-menu ul.nav >li >ul.sub-menu:before{content:'';display:block;width:0;height:0;border-style:solid;border-width:0 10px 10px 10px;border-color:transparent transparent #000000 transparent;position:absolute;top:-10px;left:30px}.dl-menu ul.nav >li >ul.sub-menu:before{left:50%;transform:translateX(-50%)}