**Steps to replicate the issue** (include links if applicable):
* Navigate to https://pl.wikipedia.org/w/index.php?title=Wikipedia&diff=67420508&oldid=66986323&diffmode=source&uselang=en&useskin=vector-2022
* Scroll below the side-by-side comparison
**What happens?**:
The table of contents is unstyled and shown inline:
{F35485426}
**What should have happened instead?**:
The TOC should look like the one on article pages and be floating at the left-hand side.
**Software version** (skip for WMF-hosted wikis like Wikipedia): plwiki
**Other information** (browser name/version, screenshots, etc.):
The issue seems to appear on all special pages that have ToC, for example: Diff, EditWatchlist (only if 31+ pages on the watchlist from 2 or more namespaces).
The issue affects also the main page (and AFAIK only the main page apart from specials) at https://pl.wikimedia.org/wiki/Strona_g%C5%82%C3%B3wna?useskin=vector-2022&uselang=en
This seems to be related to T308216