**List of steps to reproduce** (step by step, including full links if applicable):
* Visit https://en.m.wikipedia.org/wiki/Main_Page
**What happens?**:
<h2>s (inside a table?) apparently get a new class `in-block` which sets `display: table`. Effect, the lack of full-width titles on the main page:
{F34940176}
Occurs only on mobile domain, all skins; all skins on desktop fine.
**What should have happened instead?**:
Don't do that. I have no idea why this is happening (I'm guessing as some sort of mitigation for tables on mobile) but pretty sure it's also not good for the uses in the wild of headings inside tables (yes, that's a thing, as a work around for lack of sticky table headers). I honestly can't fathom why this was done, but regardless, it shouldn't be done for headings.
**Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc.**:
1.38.0-wmf.19 (664d5ad)
16:10, 24 January 2022