.site-overlay {
	height: 200%;
	width: 100%;
	position: fixed;
	z-index: 2;
	top: 0;
	left: 0;
	background: rgba(0, 0, 0, .6);
	opacity: 0;
	visibility: hidden;
	transition: all .2s linear;
}

.site-nav-open .site-overlay {
	opacity: 1;
	visibility: visible;
}