Confusion of the official document site and the spectre css itself
As a normal user, i expect the official document site is built with the spectre css itself without a lot customization. But the site has custom style docs.min.css (with many class name prefixed with doc-), it makes the document site looks different (more beautiful) than the site we built with pure spectre css. Same thing happens to your https://rework.tools.
is it possible to merge docs.min.css (and probably https://rework.tools too) to spectre css?
That's exactly the strong point of Spectre. We use it because it's lightweight providing a base for modern web applications which can be customized to have any other look without major issues.
I think that adding more and more classes that are probably going to be overrided is only going to make spectre bloated.