.single-gallery.mosaic .thumb-elem-header .image-title {
position: absolute;
z-index: 10;
color: white;
background: black;
top: 10px;
left: 5px;
}
.single-gallery.mosaic .thumb-elem-header .image-description {
position: absolute;
z-index: 10;
color: white;
background: black;
bottom: 10px;
left: 5px;
}