.scroll-bottom {
    position: fixed;
    bottom: 3em;
    left: 0;
    right: 0;
    width: 100px;
    margin: 0 auto;
    text-align: center;
    z-index: 10;
    -webkit-transition: opacity 1s;
    transition: opacity 1s;
    -webkit-animation-duration: 1s;
    animation-duration: 1s;
    -webkit-animation-name: slidein;
    animation-name: slidein;
    -webkit-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
}

.scroll-bottom.hidden {
    opacity: 0;
}

@-webkit-keyframes slidein {
    from {
        -webkit-transform: translate3d(0, 0, 0);
        transform: translate3d(0, 0, 0);
    }
    to {
        -webkit-transform: translate3d(0, 50px, 0);
        transform: translate3d(0, 50px, 0);
    }
}

@keyframes slidein {
    from {
        -webkit-transform: translate3d(0, 0, 0);
        transform: translate3d(0, 0, 0);
    }
    to {
        -webkit-transform: translate3d(0, 50px, 0);
        transform: translate3d(0, 50px, 0);
    }
}