Description

The responsive hide feature uses media queries. If there is no wrapper tag, the class is not added, and the hide CSS will not be applied.

A support flag like

"visibility": {
  "viewport": false
}

might be necessary in block.json's supports property.

This feature will be introduced from WordPress 7.0, so a backport might be necessary.

Step-by-step reproduction instructions

1. Go to post or page.
2. Insert custom html block.
3. Hide on Desktop
4. You will see that the content of the custom HTML block is displayed on desktop as well.

Screenshots, screen recording, code snippet

Environment info

• WordPress beta 2

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure