txwx_mobile/special_course/assets/animate/source/specials/hinge.css

@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;
}