.block-editor-block-list__block.wp-block-mvc-archive-image {
    border: 2px dashed #999;
    padding: 1rem;
    background: #fcfcfc;
    text-align: center;
}
.mvc-archive-image-wrapper img.mvc-archive-featured-image {
    width: 100%;
    height: auto;
    display: block;
}