@keyframes flipOutX {
  0% {
    transform: perspective(400px) rotateX(0deg);
    opacity: 1;
  }

  100% {
    transform: perspective(400px) rotateX(90deg);
    opacity: 0;
  }
}

.flipOutX {
  animation-name: flipOutX;
  backface-visibility: visible !important;
}