.figure {
position: relative;
float: left;
overflow: hidden;
margin: 1.5em;
}
.figcaption {
position: absolute;
bottom: 0;
left: 0;
width: 100%;
height: 100%;
background-color: #2ecc71;
color:#fff;
opacity: 0;
}
img {
display: block;
}