style.css

.photo-grid figcaption {
	background: rgba(0,0,0,0.8);
	color: white;
	display: table;
	height: 100%;
	left: 0;
	opacity: 0;
	position: absolute;
	right: 0;
	top: 0;
	-webkit-transition: all 300ms;
	-moz-transition: all 300ms;
	transition: all 300ms;
	-webkit-transition-delay: 100ms;
	-moz-transition-delay: 100ms;
	transition-delay: 100ms;
	z-index: 100;
}