#prev,
#next {
    position: fixed;
    top: 50%;
    width: 64px;
    opacity: 0.0;
    transition: opacity 0.5s ease;
    visibility: visible;
}

#prev {
    left: 0;
    transform: scaleX(-1);
}

#next {
    right: 0;
}

#prev_m, #next_m {
    height: 0px;
    width: 0px;
 }

#prev_m {
    transform: scaleX(-1);
}

@media (pointer:none), (pointer:coarse) {

    #prev_m, #next_m {
        height: 64px;
        width: 64px;
    }
}