#back2Top {
    width: 40px;
    height: 40px;
    line-height: 2;
    margin-right: 10px;
    overflow: hidden;
    z-index: 999;
    display: none;
    cursor: pointer;
    -moz-transform: rotate(270deg);
    -webkit-transform: rotate(270deg);
    -o-transform: rotate(270deg);
    -ms-transform: rotate(270deg);
    transform: rotate(270deg);
    position: fixed;
    bottom: 50px;
    right: 0;
    background-color: #DDD;
    color: #111;
    text-align: center;
    font-size: 20px;
    text-decoration: none;
}
#back2Top:hover {
    background-color: var(--back2top_bg_color_on_hover);
    color: var(--back2top_color_on_hover)
}