@media (min-width: 600px) {
    body .wp-block-gallery.has-nested-images.columns-5 figure.wp-block-image:not(#individual-image) {
        width: calc(20% - 16px);
    }
    body .wp-block-gallery.has-nested-images.columns-4 figure.wp-block-image:not(#individual-image) {
        width: calc(25% - 16px);
    }
    body .wp-block-gallery.has-nested-images.columns-3 figure.wp-block-image:not(#individual-image) {
        width: calc(33.333% - 16px);
    }
    body .wp-block-gallery.has-nested-images.columns-default figure.wp-block-image:not(#individual-image) {
        width: calc(33.333% - 16px);
    }
}