Comment by Volker-E

You can try https://en.wikipedia.org/wiki/User:Volker_E._(WMF)/dark-mode for now. It's a black/night mode at the moment. And (not yet) an official option with some technical acceptance issues like lazy-loading, therefore flicker on load. – I work for the Wikimedia Foundation. This wish has been stated as part of the Community Wishlist survey 2019. https://meta.wikimedia.org/wiki/Community_Wishlist_Survey_20...