.lightbox-visible {
    display: block;
}

.lightbox-hidden {
    display: none;
}

.lightbox {
    position: fixed;
    z-index: 999;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 1em;
    background: rgba(0, 0, 0, 0.8);
}

.lightbox div {
    display: block;
    width: 100%;
    height: 100%;
    background-position: center;
    background-repeat: no-repeat;
    background-size: contain;
}