Stylus should rotate dark styles with normal styles based on geoposition and timezone by default. Similar to the https://addons.mozilla.org/en-US/firefox/addon/automatic-dark https://github.com/skhzhang/time-based-themes

I use this to write CSS to fix broken sites and remove overintrusive ads that escape ad blocker. Actually works, unlike new Stylish. Interface a bit clunky, hence 4 stars.

does not work on loaded local pdf files. stylus says "Firefox forbids access to the site, In Firefox 60 and newer you need to remove this domain from extensions.webextensions.restrictedDomains in about:config."

however the local files are not in any domain