#top-link {
    --scroll: 0%;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    position: fixed;
    right: 20px;
    bottom: 20px;

    background:
        conic-gradient(
            #7a2ee7 var(--scroll),
            rgba(0,0,0,.15) 0%
        );

    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    cursor: pointer;
}

/* Tạo nút bên trong */
#top-link::before {
    content: "";
    position: absolute;
    inset: 4px;
    background: #fff;
    border-radius: 50%;
    z-index: -1;
}

/* Icon mũi tên */
#top-link i {
    font-size: 18px;
    color: #333;
    position: relative;
    z-index: 2;
}