.hidden {
    display: none;
}

div.slideshow {
    display: flex;
    justify-content: center;
    align-items: center;
    background: gray;
    color: white;
}

div.slideshow img {
    width: calc(100% - 2 * 100px);
}

div.slideshow img.arrow {
    width: 100px;
}

div.slideshow img.arrow.previous {
    transform: rotate(180deg);
}