editor.css

.prose {
  :not(:where($(where-not))) {
    /**
     * Without Preflight, Tailwind doesn't apply a default border
     * style of `solid` to all elements, so the border doesn't
     * appear in the editor without these additions.
     */
    &:where(blockquote) {
      border-left-style: solid;
    }

    &:where(tbody tr) {
      border-bottom-style: solid;
    }
  }

  .wp-block-table td,
  .wp-block-table th {
    border: 1px dashed rgb(0 0 0 / 0.075);
    border-top: 0;
    border-bottom: 0;
  }

  .wp-block-table td:first-child,
  .wp-block-table th:first-child {
    border-left: 0;
  }

  .wp-block-table td:last-child,
  .wp-block-table th:last-child {
    border-right: 0;
  }
}