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 {
	position: fixed;
	left: 1%;
	right: 1%;
	width: 763px;
	margin: 50px auto 0;
	text-align: center;
	z-index: 2000;

}

.btn_close{
margin: 20px auto;
}