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

@include keyframes(hinge) {
  0% {
    -webkit-transform-origin: top left;
    transform-origin: top left;
    -webkit-animation-timing-function: ease-in-out;
    animation-timing-function: ease-in-out;
  }

  20%, 60% {
    -webkit-transform: rotate3d(0, 0, 1, 80deg);
    transform: rotate3d(0, 0, 1, 80deg);
    -webkit-transform-origin: top left;
    transform-origin: top left;
    -webkit-animation-timing-function: ease-in-out;
    animation-timing-function: ease-in-out;
  }

  40%, 80% {
    -webkit-transform: rotate3d(0, 0, 1, 60deg);
    transform: rotate3d(0, 0, 1, 60deg);
    -webkit-transform-origin: top left;
    transform-origin: top left;
    -webkit-animation-timing-function: ease-in-out;
    animation-timing-function: ease-in-out;
    opacity: 1;
  }

  100% {
    -webkit-transform: translate3d(0, 700px, 0);
    transform: translate3d(0, 700px, 0);
    opacity: 0;
  }
}