html,body{height:100%}* html .layer_board_bg,* html .layer_board{position:absolute}.layer_board_bg{position:fixed;width:100%;height:100%;z-index:1000;top:0;left:0;display:none;cursor:pointer;background:#000}.layer_board{display:none;position:fixed;text-align:center;z-index:2000;top:25%;left:0;right:0}