I use a clean (and minimal) old-school themed design from Curiositry (https://news.ycombinator.com/user?id=curiositry) for my blog @ oddlinks.com.
I'm quite biased, but rather like the elegantly simple and retro style.
https://www.curiositry.com/weblog-ghost-theme/about/index.ht...
I enjoyed https://shipilev.net/labs/network-de/
It's similar to my own personal knowledge base (non-public at the moment), but I like it enough that I used it as a reference to tweak my own a bit. The output seems to come from Asciidoctor, but I don't know if it's been modified.
Definitely a biased opinion, but I don't mind my collection of notes. As a sample: https://simple.industries/notes/counting.html
I've been slowly hacking at a system that lets me jot things down with markdown and latex in Obsidian, then render in a mostly clean and lightweight form. The build pipeline is just a bash script and pandoc to keep tooling as thin as possible too.
I hope to have time to expose the underlying graph in yet to be defined way, but have neither the time or amount of content to warrant that yet. A source of inspiration and admiration for that is definitely https://notes.andymatuschak.org/.
I love this jekyll theme called "sidey" and whenever I need one I just use this https://github.com/ronv/sidey
my blog using a little bit cleaned version https://umtksa.github.io/
The typography plugin which comes out of tailwind gives a clean readable experience in my opinion. https://tailwindcss.com/docs/typography-plugin
Not many, but some people have emailed me with compliments about the functional desing of this post:
https://edwardtufte.github.io/tufte-css/