@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% {
        @include 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% {
        @include 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% {
        @include translate3d(0, 700px, 0);
        opacity: 0;
    }
}

.hinge {
    -webkit-animation-name: hinge;
    animation-name: hinge;
    -webkit-animation-duration: 2s;
    animation-duration: 2s;
}