@charset "utf-8";

#btn {
    width: 60px;
    position: fixed;
    z-index: 10;
    bottom: 100px;
    right: 50px;
    cursor: pointer;
}

#btn img {
    width: 100%;
    margin-bottom: 20px;
}

#top {
    transition: background 0.2s;
}