.perspectiveDown {
  -webkit-animation-name: perspectiveDown;
          animation-name: perspectiveDown;
}
@-webkit-keyframes perspectiveDown {
  0% {
    -webkit-transform-origin: 0 100%;
            transform-origin: 0 100%;
    -webkit-transform: perspective(800px) rotateX(0deg);
            transform: perspective(800px) rotateX(0deg);
  }

  100% {
    -webkit-transform-origin: 0 100%;
            transform-origin: 0 100%;
    -webkit-transform: perspective(800px) rotateX(-180deg);
            transform: perspective(800px) rotateX(-180deg);
  }
}
@keyframes perspectiveDown {
  0% {
    -webkit-transform-origin: 0 100%;
            transform-origin: 0 100%;
    -webkit-transform: perspective(800px) rotateX(0deg);
            transform: perspective(800px) rotateX(0deg);
  }

  100% {
    -webkit-transform-origin: 0 100%;
            transform-origin: 0 100%;
    -webkit-transform: perspective(800px) rotateX(-180deg);
            transform: perspective(800px) rotateX(-180deg);
  }
}