Firefox: System theme — auto

[evgeniy-harchenko]

I use Qogir-manjaro theme, so I have applications with dark headerbar and light other part of window. I installed Firefox theme and selected this theme in Firefox:

Everything works well, but headerbar in Firefox is light (expected dark - as system theme). Here is comparison:

Left - my all apps appearance, right - Firefox. Also here you can see that private mode label is faded, like it from dark variant of theme.
Is it possible to fix this somehow? is it possible to make Firefox theme fully match the system theme?