#gallery .tile .caption {
position: absolute;
display: block;
left: 0;
top: 0;
width: 100%;
height: 100%;
opacity: 0;
-webkit-transition: opacity 0.3s;
-moz-transition: opacity 0.3s;
-o-transition: opacity 0.3s;
transition: opacity 0.3s;
background: rgba(0,0,0,.4);
}
#gallery .tile:hover .caption {
opacity: 1;
}
#gallery .tile:hover {
cursor: pointer;;
}