.mouse {
    width: 2em;
    height: 3em;
    font-size: 18px;
    border: 0.25em solid #fff;
    border-radius: 1em;
}

.mouse::before {
    content: '';
    display: block;
    width: 0.3em;
    height: 0.5em;
    margin-left: calc(50% - 0.15em);
    margin-top: 0.6em;
    background-color: #fff;
    border-radius: 0.15em;
    animation-name: scroll;
    animation-duration: 0.9s;
    animation-iteration-count: infinite;
}
.mouse:hover::before {
    animation-play-state: paused;
}

@keyframes scroll {
    0% {
        margin-top: 0.6em;
    }
    100% {
        margin-top: 1.5em;
    }
}