Menu font gets smaller and bar jumps down on smaller screens.

I’m working with this theme but am running into a small issue. I had to manually edit the header in order to use a .svg vector file for the logo since I can’t upload SVGs directly to a wordpress site.
On smaller screens <1024px the font size of the menu bar gets smaller (don’t mind this) but the entire menu bar also jumps down a bit. In the stock theme it’s not that much, it jumps about 10 pixels down, but with my custom header (I only removed the logo code and replaced it with an image tag) it jumps down about 70 pixels, which is a real issue.
Is there any way I can get this jump to not occur or be smaller again? Or is there a way to use an .svg through the main wordpress interface?