html {
 background-color: #000;
}

.ui-full {
  position: relative;
  display: block;
  margin: auto;
}

.ui-full img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
}

.ui-full img:nth-child(2) {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: -1;
}

.ui-link:hover ~ img:nth-child(2) {
  z-index: 2;
}

.ui-link {
  display: block;
  position: absolute;
  z-index: 99;
  width: 50%;
  height: 90%;
}