@heyzsh @Toni There is a clunky(image colors reversed) way to have a dark mode in Firefox here: https://www.reddit.com/r/firefox/comments/eztxrw/dark_mode_for_firefoxs_builtin_pdf_viewer/Basically, you create a subfolder named "chrome" in the Firefox...
@akincisorThere's an extension called SingleFile, which saves the current webpage as a single html file, viewable via the browser. I think this is what you're looking for. Or maybe you have other needs?