.flip-container {
  background: transparent;
  display: inline-block;
}

.flip-this {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}

.flip-container:hover .flip-this {
  transition: 0.9s;
  transform: rotateY(180deg);
}