I’ve spent the last few weeks writing a browser extension that lets users write their own HN themes using Handlebars and CSS. It works by converting the current Hacker News page’s content into an object that is made available to the user-defined Handlebars templates. There is a built-in code editor that makes writing themes super easy and you can see changes in real-time. If you don’t want to write a theme from scratch, there are premade themes available or you may import one made by somebody else.
It is shipped with Bootstrap so you can get pretty far without needing to write a lot of custom CSS. Material icons are also included so your themes get iconography out of the box. Any theme can be toggled into dark mode with a single click.
It is open-sourced under the MIT license so feel free to use any of the code in the linked repo[0]. Additionally, I’ve put together a short demo video on YouTube[1]. If you decide to check it out, let me know of any feedback and please share any themes you create! I’d be happy to answer any questions.