Wordpress-plugin-Gutenberg-Block/src/block/editor.scss

/**
 * #.# Editor Styles
 *
 * CSS for just Backend enqueued after style.scss
 * which makes it higher in priority.
 */

 .wp-block-cgb-block-mobilizon  {
  // background: $green;
  // border: 0.2rem solid $black;
  // color: $black;
  margin: 0 auto;
  max-width: 600px;
  padding: 1rem;
  img.wp-block-cgb-mobilizon-icon {
    height: 5rem;
    width: 5rem;
    margin-right: 0.7rem;
  }
}