.swing-in-top-fwd, .dropdown-menu {
    -webkit-animation: swing-in-top-fwd 0.5s
        cubic-bezier(0.175, 0.885, 0.32, 1.275) both;
    animation: swing-in-top-fwd 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275)
        both;
}

@-webkit-keyframes swing-in-top-fwd {
    0% {
        -webkit-transform: rotateX(-100deg);
        transform: rotateX(-100deg);
        -webkit-transform-origin: top;
        transform-origin: top;
        opacity: 0;
    }
    100% {
        -webkit-transform: rotateX(0deg);
        transform: rotateX(0deg);
        -webkit-transform-origin: top;
        transform-origin: top;
        opacity: 1;
    }
}
@keyframes swing-in-top-fwd {
    0% {
        -webkit-transform: rotateX(-100deg);
        transform: rotateX(-100deg);
        -webkit-transform-origin: top;
        transform-origin: top;
        opacity: 0;
    }
    100% {
        -webkit-transform: rotateX(0deg);
        transform: rotateX(0deg);
        -webkit-transform-origin: top;
        transform-origin: top;
        opacity: 1;
    }
}