This looks like it should be so simple; and I have found where I think I should be able to make this adjustment. But absolutely nothing happens

I am trying to increase the size of the font of the primary menu (transparent menu), as well as bold face it.

In the panel, I go from Appearance and Customize, then Header, then Transparent Header
I click on the Design tab. There is nothing there that says “font control”.

So I go back to Header and select “Primary Navigation”, then the Design tab. There I see “Navigation Font”. It currently says “Inherit”, “Inherit”, “Inherit”.
I click on the middle “inherit” and change the style to “Ultra-Bold 900”.
I click on the size tab, and change the font size from 17 to 24.

I click on Publish – and nothing changes anywhere.

The page I need help with: [log in to see the link]