I made a script you can save as a bookmark, that will allow you to toggle on/off dark mode on any website.

It doesn't always work flawlessly, but 90% of the time it works everytime. I think it works great on HN.

The script:

javascript:(()=>{const i="__dmcss__",s=document.querySelector("#"+i);s?s.remove():document.head.innerHTML += "<style id=\""+i+"\">html{background:white;filter:invert(0.92) hue-rotate(180deg);}img,video,object{filter:invert(1) hue-rotate(180deg);}</style>";})()

How to add: right click bookmarks bar => Add page => paste this in the URL input.