#background {
	position: fixed;
	height: 200%;
	width: 200%;
	left: -50%;
	top: -50%;
}
#background img {
	margin: auto;
	position: absolute;
	left: 0px;
	top: 0px;
	right: 0px;
	bottom: 0px;
	min-width: 50%;
	min-height: 50%;
}
#interface {
	z-index: 2;
	position: relative;
}