Where is the rich_doc CSS class defined?

[neverlink]

I see this class appears in a few PRs, also in the source code, but with no definition?

Context: I want to improve the style of Makrdown tables, as described in this comment.

• Is this dead code or does it stem from a different codebase?
• Where should this class be modified?

[neverlink]

Regarding my specific use case - at this rate, raw HTML is being removed on the next release.
This means Markdown tables will be rendered with no style, except for the inherited font.

[neverlink]

Closing because this will probably be tackled or at the very least change with Airflow 3.0's new UI