I'm learning JavaScript/HTML/CSS and I want to develop a simple website for teachers to manage their students. However, I don't intend to host it on a server. Instead, I'd make the source code available so teachers could just download it, open the index.html file on their browsers and be good to go.

However, I need a way to store their data locally, but I don't want to use local-storage because they might lose their data if they switch browsers, for example. I was thinking of something like a JSON file that they could be stored locally or in the cloud, but I can't seem to get it working without additional libraries. The idea is that users must be able to just download the files and use them right away, without having to install anything else.

What should I look into in order to be able to do this?