@keyframes hinge {

  0% {

    transform-origin: top left;

    animation-timing-function: ease-in-out;

  }



  20%,

  60% {

    transform: rotate3d(0, 0, 1, 80deg);

    transform-origin: top left;

    animation-timing-function: ease-in-out;

  }



  40%,

  80% {

    transform: rotate3d(0, 0, 1, 60deg);

    transform-origin: top left;

    animation-timing-function: ease-in-out;

    opacity: 1;

  }



  to {

    transform: translate3d(0, 700px, 0);

    opacity: 0;

  }

}



.hinge {

  animation-duration: 2s;

  animation-name: hinge;

}

