carr c3 a9 css

1.square {
2  position: relative;
3  width: 50%;
4}
5
6.square:after {
7  content: "";
8  display: block;
9  padding-bottom: 100%;
10}
11
12.content {
13  position: absolute;
14  width: 100%;
15  height: 100%;
16}