In any diff view (e.g. https://de.wikipedia.org/w/index.php?title=Wikipedia%3AHauptseite&type=revision&diff=152425751&oldid=151585132, for some reason I can't reproduce on en.wikipedia while logged in) the style for the comments is missing. The comments should be shown in italic.
This is caused by rMW9e458504c7b4: Move changeslist CSS classes from mediawiki.legacy.shared (or rather rMWb88cc6edd1be: Follow-up 6af8dcf: Remove duplicate styles in shared.css).