.flash-card {
  background-color: transparent;
  width: 300px;
  height: 135px;
  perspective: 1000px;
}

.flash-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.7s;
  transform-style: preserve-3d;
  box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2);
}

.flash-card:hover .flash-card-inner {
  transform: rotateY(180deg);
}

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

.flash-card-front {
  color: white;
}

.flash-card-back {
  color: white;
  transform: rotateY(180deg);
}
