Blurry logo in header - scaling?

I’m having an issue with the logo size on demoside.frikit.no:
Even if I add a larger logo file, it looks blurry. I suspect there is some sort of scaling of the logo going on, that I don’t manage to adjust. I’ve tried logo sizes from 600 - 2000 pixels wide. (I’m happy with the size it displays now, but the actual file is now being enlarged about 30-40 %)

Hello,

Please create a separate topic for each of your issues to keep forum in good order and make it easier to help you.

Kind Regards, Roman.