Totally feel you there — I’m studying too, and puzzles are my go-to brain reset. I use
https://puzzlefree.game/
almost every evening. It’s all in-browser, no downloads or registrations, and it works like a charm even on my old laptop. You can pick from tons of images and choose the difficulty depending on how much brainpower you have left. It’s super relaxing and ad-free. Honestly, it’s my favorite little study break activity now.