GTK fonts in Firefox menus changed, after upgrade?

[nick_battle]

I’ve just done a “zypper dup” up to 20251121-3816.1. There is an annoying difference in the menu/toolbar fonts used by Firefox. KDE apps are fine.

My chosen general/menu font (in KDE) is “DejaVu Sans Condensed” 10pt, and that appears in both GTK3/4 settings.ini files. But Firefox looks like it is either falling back to Arial or perhaps the non-condensed DejaVu (hard to tell!).

gtk-font-name=DejaVu Sans Condensed, 10

Any ideas how to fix this, or what has happened?

[swannema]

That change happened with the update to plasma 6.5.3. You can try to change ~/.config/gtk-3.0/gtk.css.
The link gives you possible font settings.
I only had to adapt the font weight a little bit with

* { font-weight: 500; }

[nick_battle]

Thanks Stefan, that did the trick! The following gtk.css seems to look right to me:

@import 'colors.css';
* {
    font-family: "DejaVu Sans Condensed";
    font-weight: 500;
    font-stretch: semi-condensed;
    font-style: normal;
    font-size: 10pt;
}