.qrcode{
	position: fixed;
	left: 0;
	right: 0;
	top: 0;
	bottom: 0;
	background-color: rgba(0,0,0,0.5);
	z-index: 100;
	display: none;
}
.qrcode img{
	position: absolute;
	left: 50%;
	top: 50%;
	transform: translate(-50%,-50%);
	width: 50vmin;
	height: auto;
}