.media-gallery { max-height: 400px !important; }
.media-gallery__item-thumbnail img { object-fit: contain !important; }

div.focusable { border-top: 5ex solid black !important; }

div.columns-area__panels,
div.navigation-panel,
div.ui__header {
    background: black !important;
}

div.navigation-panel { border-left: 2ex solid black !important; }