#gallery {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    column-gap: 10px;
    column-count: 2;
}

#gallery * {
    box-sizing: inherit;
}

#gallery div.img-container {
    padding: 0;
    margin-bottom: 10px;
    width: 100%;
}

#gallery div.img-container img {
    width: 100%;
    height: auto;
    display: block;
    cursor: pointer;
    margin: 0 auto;
    image-orientation: from-image;
}

#gallery-showcase {
    position: fixed;
    padding: 10px;
    width: 100%;
    height: 100%;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: rgba(0,0,0,0.75);
    display: none;
    grid-template-rows: 100%;
    grid-template-columns: auto auto auto;
    justify-content: space-between;
    z-index: 2;
}

#gallery-showcase-img {
    max-width: 100%;
    max-height: 100%;
    align-self: center;
    justify-self: center;
}

#left, #right {
    cursor: pointer;
    z-index: 1;
    color: white;
    align-self: center;
    font-size: 5em;
}

@media screen and (min-width: 525px) {

    #gallery {
        column-count: 3;
    }
}

@media screen and (min-width: 825px) {

    #gallery {
        column-count: 4;
    }
}

@media screen and (min-width: 1150px) {

    #gallery {
        column-count: 5;
    }
}

@media screen and (min-width: 1450px) {

    #gallery {
        column-count: 6;
    }
}