The default Breeze theme for SDDM on KDE uses default fonts from somewhere I don't know of. In earlier versions of KDE/SDDM, there used to be specific files in the SDDM themes where a font could be set (using something like
PlasmaComponents.Label). However, in newer versions (Plasma/sddm-breeze 5.10.1-1, sddm 0.14.0-10 on Fedora 26) everything seems to have been rearranged and I can't find any file(s) where the font can clearly/obviously be set.
I would like to change the font for preferably all UI elements. I found this post but couldn't glean much useful information from it. One option in particular, got by following a link in that post, is to just change the system's default (fallback) fonts, and that is something I definitely don't want to do (I need the default fonts as they are for other reasons). I also tried the option mentioned in the original post, by the author of an SDDM theme, of setting the font in the
theme.conf file, but to no avail. (To be fair, the author does mention that this technique won't work with other themes. :( )
Is there really a way to change the SDDM font, particularly for the Breeze theme?