Toggle theme option when signed out

I would appreciate if GitHub could have a toggle button in order to change between themes when signed out. I use Windows, and have my OS settings set to complete dark mode but I don’t want websites to be dark as well as I can’t really read or focus on the text.
Most websites sync with my OS which isn’t really a problem if there’s a button somewhere to toggle off, however, this doesn’t happen on GitHub if you’re signed out, which I face a lot.