This looks pretty great and smart to split the CSS into separate pages!
Do you have any advice on how to get started with theming? Did you just look at what variables are available and where they are used or is there some documentation available to make this easier to do?
(Off-topic: you have many icons in the top bar, I recognize Git, but what do the others link to?)
Being able to split the CSS into separate files, as well as being able to even further break them down into blocks of space-style with markdown between (Jupyter Notebook style) is a hidden super power of SilverBullet, I’d say.
I pretty much went element by element by inspecting it with the browser dev tools and tweaking the values. I don’t think there is dedicated documentation to themeing – or I haven’t found it at least