Refactor CSS to be mobile first

[fulldecent]

Currently, CSS is factored to have the base case be desktops (i.e. mobile code is inside @media (max-width: 760px)).

However nowadays mobile traffic is the majority. So best practice is that the CSS be written smaller viewports first and then use more specificity for larger viewports (e.g. @media (min-width: 760px)).

[daveliepmann]

My work the last few years has been largely back-end, so I'm not familiar with that best practice. It sounds reasonable, but I'd like to see some sources. Regardless, I refer you (again) to Project Scope and Status from the README:

This project is maintained but not under active development. It is considered essentially feature-complete. Refactoring and new functionality are a very low priority. However, contributions are still welcome to fix bugs or add functionality.

I'm not going to spend the (substantial) time necessary to refactor tufte.css to fulfill a best-practices checkbox. The project works as-is and I don't plan to spend a lot of time on it unless funding is made available. If you're interested in providing funding, please contact me by email.

If you did the work and submitted a PR, I'd review it positively and it might get merged. But I'd need to see fairly comprehensive evidence showing that such a substantial change preserved functionality on a variety of devices and documents before moving forward, though. So that's a major prerequisite. Until then I'm going to close this.

[fulldecent]

FYI, I'm opening issues here to document initiatives for things I am implementing that may possibly be in project scope. I'm just deciding for myself which things to contribute upstream or which to keep for myself.