docmost/apps/client/src/features/editor/styles/base-embed.css

.ProseMirror {
  .node-baseEmbed {
    /* Suppress the default ProseMirror atom-node selection outline —
     * the embed reads as a document block, not a focused widget. */
    &.ProseMirror-selectednode {
      outline: none;
    }
  }
}