onders.org_zola_theme/sass/onders.org/_gallery.scss

div.gallery {
    width: calc(100% + 10px);
    margin-left: -5px;
    line-height: 0;
    margin-bottom: 2.5rem;
}

div.gallery img.thumbnail {
    padding: 5px;
}

div.gallery a img.thumbnail:hover {
    box-shadow: 0 0 0px $color-tertiary !important;
    transform: scale(1.1);
    transition: transform .2s;
}

div.lightbox {
    opacity: 0;
    z-index: 700;
    transition: opacity 0.2s linear;
    position: fixed;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    background-color: rgba($color-black, 0.7);
    overflow: auto;
    display: flex;
    justify-content: center;
    align-items: center;
    pointer-events: none;
    @supports ((-webkit-backdrop-filter: none) or (backdrop-filter: none)) {
        -webkit-backdrop-filter: blur(5px);
        backdrop-filter: blur(5px);
    }
}

div.lightbox:target {
    opacity: 1;
    pointer-events: auto;
}

div.lightbox a.full {
    height: 100%;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

div.lightbox span {
    font-size: 2em;
    line-height: normal;
    position: absolute;
    color: $color-tertiary;
    cursor: pointer;
}

div.lightbox span:hover {
    color: $color-secondary;
}


div.lightbox span.close {
    z-index: 900;
    top: 0;
    right: 0;
    padding: .7em 1em;
}

div.lightbox span.close:before {
    content: "✖";
    font-size: 1.2em;
}

div.lightbox span.prev {
    z-index: 800;
    top: 0;
    left: 0;
    display: inline-flex;
    align-items: center;
    font-size: 6em;
    height: 100%;
    padding: 0 .3em;
}

div.lightbox span.prev:before {
    content: "‹";
}

div.lightbox span.end:before {
    content:  "⟳";
    font-size: .7em;
}

div.lightbox span.next {
    z-index: 800;
    top: 0;
    right: 0;
    display: inline-flex;
    align-items: center;
    font-size: 6em;
    height: 100%;
    padding: 0 .3em;
}

div.lightbox span.next:before {
    content: "›";
}

div.lightbox span.start:before {
    content:  "⟲";
    font-size: .7em;
}

div.lightbox div.image {
    display: flex;
    justify-content: center;
    width: 80%;
    height: 80%;
}

div.lightbox div.image img {
    filter: drop-shadow(0 0 10px $color-black);
    object-fit: contain;
    max-height: 100%;
    max-width: 100%;
    width: 100%;
    height: auto;
}