When scaling screen size down, my primary menu is switched to a hamburger mobile view too quickly. How do I change this so the desktop view is visible longer? For example, if the hamburger kicks in at 1024px, I want to change it so it kicks in at 960px. I have a lot of custom CSS on this site, but I can't find the setting to make this work. The site is https://www.gentryfoto.com/

Thanks!