.mouse-scroll {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    pointer-events: none;
}

.mouse-shell {
    position: relative;
    width: 20px;
    height: 30px;
    border: 1px solid white;
    border-radius: 20px;
}

.mouse-wheel {
    position: absolute;
    left: 50%;
    margin-left: -4px;
    top: 6px;
    width: 5px;
    height: 8px;
    border: 1px solid white;
    border-radius: 20px;
    
    transform: translateY(4px);

    animation-duration: 1.0s;
    animation-name: mouse-scroll-anim;
    animation-iteration-count: infinite;
    animation-direction: alternate;
    animation-timing-function: ease-in-out;
}

@keyframes mouse-scroll-anim {
    from {
        transform: translateY(-2px);
    }
    to {
        transform: translateY(2px);
    }
}