.mouse {
    width: 50px;
    height: 100px;
    border: 3px solid white;
    border-radius: 50px;
    position: absolute;
    left: 50%;
    bottom: 50px;
    transform: translate(-50%, 0);
}

.mouse::before {
    position: absolute;
    content: "";
    width: 10px;
    height: 10px;
    background-color: white;
    left: 50%;
    transform: translate(-50%, 0);
    top: 20px;
    border-radius: 50%;
    animation: scroll 2s infinite;
}

@keyframes scroll {
    from {
        top: 20px;
        opacity: 1;
    }
    to {
        top: 80px;
        opacity: 0;
    }
}