#main_gangqin{margin:0 auto;width:600px;height:420px;position:relative}.key{position:absolute;float:left;top:40px;text-align:center;font-size:16px;background-position:bottom left;background-repeat:repeat-x}.whiteKey{width:60px;height:360px;color:#666;background-color:#eee;border:2px solid #999;background-image:url("../image/key_back_white.png")}.blackKey{width:36px;height:200px;color:#ccc;background-color:#666;border:2px solid #666;background-image:url("../image/key_back_black.png")}.whiteKey span{background-color:#444;position:relative;top:500px}.blackKey span{position:relative;top:-50px}