if you’re wanting to increase the logo size without effecting the height of the nav, the best thing to do would be crop the original logo image. Let me know if i have misunderstood..
Sorry if this is not clear, I want to keep the logo size the same but make the navigation bar smaller, when I try to make the navigation bar smaller it automatically makes the logo smaller as well making too hard to see.
Your logo image is square with a lot of white space above and below it. Try cropping the image to remove the white space. Then you will be able to reduce the nav height without it considerably reducing the logo size.