[interf4ce]

Whether this is actually beneficial (let alone possible) depends heavily on the type of site.

Web apps that are valuable to use offline also tend to be the kind that really do warrant client-side logic and rendering (a spreadsheet web app is a classic example).

If the site's focus is providing information (e.g. Wikipedia), then working offline really just means loading all the backing data into the browser, which quickly becomes impossible.

I'm sure there are cases where offline availability is a huge plus (your site might be a good example), I just don't think it's universally applicable.