How to decrease Font size KDE

how I can make the font size smaller/bigger for KDE?
it seems everything became bigger when I installed Nvidia drivers. When I go In the system settings and try to change the fonts and nothing at all happens.
Specifically Qube Os applications.

I cant help with Nvidia.
What fonts are you trying to change? In dom0 or in qubes?

I never presume to speak for the Qubes team. When I comment in the Forum I speak for myself.

Qubes os like dom0 system tools

You need to change size in the template so it is inherited by the
qubes that use it.
dom0 is simply displaying the output from the qubes.

I never presume to speak for the Qubes team.
When I comment in the Forum I speak for myself.