*{ margin:0; padding:0; list-style:none;}
.lrtk{ width:100%; height:500px; margin:0 auto; overflow:hidden; display:none; background:url(../image/20th.jpg) no-repeat center top #00aaee; text-align:center; position:relative;}
.lrtk .link{ width:100%; height:500px; display:block; z-index:10;}
.lrtk .up{ display:block; width:120px; height:12px; background:url(../image/arrow.png) no-repeat left bottom; position:absolute; left:50%; bottom:0; z-index:20; margin-left:-60px;}
.lrtk .down{ display:block; width:120px; height:12px; background:url(../image/arrow.png) no-repeat left top; position:absolute; left:50%; top:8px; z-index:20; margin-left:-60px;}