In MacOS System Prefereces on the 'Displays' pane you can select various scaling. By defaul the font is quite large, smaller text = more space. Or as another us

In MacOS System Prefereces on the 'Displays' pane you can select various scaling. By defaul the font is quite large, smaller text = more space. Or as another user commented you can select the zoom level in your browser. Or of course the developer can move things (HTML?) around in the navbar. I hope you were not looking for validation from others to fire a developer over this small issue.