Codex now defines font sizes everywhere as var(--font-size-medium, 1rem) but many skins do not have CSS variable defined so it falls back to that size. Clear regression that shouldn’t have happened with whatever the intention was. I suppose it is caused by https://www.mediawiki.org/wiki/Codex/Release_Timeline/2.0

This should be resolved by T394685. If that doesn't work, we'll revisit how else we can mitigate the impact of the scaled components.

While Vector 2010 is obviously the most important skin, I hope you folks also look at other skins and adjust that variable in them, since the issue is exactly the same in Monobook.

In T394468#10840907, @stjn wrote:

While Vector 2010 is obviously the most important skin, I hope you folks also look at other skins and adjust that variable in them, since the issue is exactly the same in Monobook.

We're using the small size in Monobook already. This results in some elements being larger than before, but still as small as could be in the new font system. This was a known compromise (see https://www.mediawiki.org/wiki/Codex/Release_Timeline/2.0#MonoBook). Everything should look appropriately scaled in Vector 2010 after integrating the small mode.

I see. I assumed the size isn’t adjusted there because it is much bigger than the rest of the skin. Ultimately, I always thought that it would be better if Monobook got adjusted to 14px/0.875rem baseline that other skins use for consistency and reducing such differences (so then people could just use zoom to adjust the entire interface), but I understand no one taking that communication work up.

An example of the kind of bug this causes:

The buttons on the history page in legacy Vector have 16px text, which is too large relative to its surroundings.

Fixing this bug would make it look like Vector-2022, where the button font size is correctly set to 14px (though not because font modes are integrated there, but with Vector-2022-specific hacks).