[half-kh-hacker]

Which dark mode are you talking about? As far as I can tell the page (& demos) don't ship any styles for prefers-color-scheme: dark at all

[rtkwe]

Reminds me of the meme of the person shoving a stick into their bikes wheel then complaining about ______. Used to get it a lot here with people complaining about sites being broken because they were hard blocking essentially all javascript, the issues are your own making here...

[shrx]

In my case firefox used the OS's (Windows 10) dark mode preference.

In about:config the layout.css.prefers-color-scheme.content-override setting was on 2 (system). Setting it to 3 (browser) turned the dark mode off.