.img-50 {
  height: 0;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  padding-top: 100%;
    position: relative;
}
.img-50 img {
    position: absolute;
    top: 0;
    right: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}