#mainImg .navi-image { position:relative;}
#mainImg .navi-image a { display:block; }
#mainImg .navi-image a { position:absolute; top:0; left:0; z-index:8; }
#mainImg .navi-image a.active { z-index:10; }
#mainImg .navi-image a.last-active { z-index:9; }