…
ul.img-list {
list-style-type: none;
margin: 0;
padding: 0;
text-align: center;
}
ul.img-list li {
display: inline-block;
height: 150px;
margin: 0 1em 1em 0;
position: relative;
width: 150px;
}
span.text-content {
background: rgba(0,0,0,0.5);
color: white;
cursor: pointer;
display: table;
height: 150px;
left: 0;
position: absolute;
top: 0;
width: 150px;
}
span.text-content span {
display: table-cell;
text-align: center;
vertical-align: middle;
}