Aimed to be as striaght forward as possible to customize yourself.
I've designed all these themes to work with the standard root.css file so people can just change the colors as they wish.
You can use a browser extension like Stylus, here's their homepage.
The manifest.json file is the only thing related to the theme in Firefox that matches the root.css. You can load this file into Firefox without uploading it to the store
using the about:debugging url. My theme is available here, however if you use a custom css root and don't want
to use the about:debugging url every time Firefox boots you'll have to upload your manifest.json as a .zip to Firefox store.
Please refer to the Home Assistant official documentation ..
https://www.home-assistant.io/integrations/frontend/#themes
Using the same root configuration we can setup logseq to match everything. I've tried to make the custom.css simple, so this file only affects the dark theme. The export.css that I setup just hides things that aren't helpful in the html preview, it doesn't add any styling. If you have multiple graphs in LogSeq that you want to theme you can save the custom.css and export.css anywhere on your computer and then import the asset into each graphs custom.css and export.css by adding something like this line to them;
@import url('assets:////C:/Users/username/notes/custom.css');
Make sure to use the full path of the files and the correct filename for export or custom.