[matt_LLVW]

stylus extension let you write styles per sites. there's also a centralized place to find already written styles. I use https://userstyles.org/styles/161954/hackernews-one-dark

[DHPersonal]

I tweaked and combined two existing Stylus entries called "Hacker News Readable" and "Hacker News Readable Dark" to make a layout that changes from light to dark mode with the system settings. https://jsfiddle.net/DHepworth/e4kwpr9j/2/