.hinge-top-fast-enter-active, .hinge-top-fast-leave-active {
    transition: opacity $t-fast-standard, transform $t-fast-standard;
    transform-origin: top center;
    transform: rotateX(0);
    opacity: 1;
}
.hinge-top-fast-enter, .hinge-top-fast-leave-to {
    transform: rotateX(-64deg);
    opacity: 0;
}