I hope that the official can come up with a CSS specification to help novices use it quickly
You need to explain better what you mean with this. Who is “the official”? And the CSS specification exists already.
I guess what we need and what you probably want is this:
- An “official” documentation of the plugin API and CSS classes used by Obsidian
- Tutorials for novices to write plugins and themes for Obsidian
While 1. can only be done by the developers, I think 2. should be done by the community, so that the developers have more time for their real work.