#back-to-top button {
    color: #2f2f2f;
    border: 0;
    background: none;
    position: relative;
}

#back-to-top {
    position: fixed;
    right: 28px;
    top: auto;
    z-index: 99;
}

#back-to-top.affix {
    bottom: 56px;
}

#back-to-top a {
    outline: none;
}

#back-to-top i {
    font-size: 30px;
}