.demo_img_bg {
    display:none;
	position: fixed;
	z-index:9000;
	top:0;
	left:0;
	right:0;
	margin:auto;
	width:100%;
	height:100%;
	text-align:center;
	background-color:rgba(0,0,0,0.7);
}
.demo_bg {
	width:9rem;
	margin-top:0.8rem;
}
.demo_close {
	width:1rem;
	margin-top:0.3rem;
}