.flip-card-inner {
  transition: transform 0.6s;
  transform-style: preserve-3d;
  box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2);
}

.flip-card .flip-card-inner.flipped {
    -webkit-transform: rotatey(180deg);
    transform: rotateY(180deg);
}

.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  height: auto;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

.flip-card-front {
  background-color: #bbb;
}

.flip-card-back {
  transform: rotateY(180deg);
}