#scroll_div .arrow-up, #scroll_div .arrow-down {
    position: fixed;
    right: 0;
    top: 50%;
    cursor: pointer;
    opacity: 0.5;
    display: none;
}

#scroll_div .arrow-up {
    margin-top: -50px;
}

#scroll_div .arrow-down {
    margin-top: 5px;
}

#scroll_div .arrow-up:hover, #scroll_div .arrow-down:hover {
    opacity: 1;
}