Where can you spend the day in Geneva without constantly having to spend money?

I’m feeling a bit cooped up in my room, but I don’t want to spend the whole day in cafés or other places where you’re expected to keep ordering something. I’m looking for good spots in Geneva where you can just spend some time working or just reading and relaxing without having to constantly spend money. Do you have any recommendations for 'third places' that would be good for this?