.slideOutDown {
  -webkit-animation-name: slideOutDown;
  animation-name: slideOutDown;
}

@include keyframes(slideOutDown) {
  0% {
    -webkit-transform: translate3d(0, 0, 0);
    transform: translate3d(0, 0, 0);
  }

  100% {
    visibility: hidden;
    -webkit-transform: translate3d(0, 100%, 0);
    transform: translate3d(0, 100%, 0);
  }
}