Improvements in tags and styles highlighting

[stolar-xyz]

While testing this extension, I noticed small differences with tags and styles highlighting that could potentially confuse things a bit

(subsections indicate differences in the attached image)

1. In my opinion, tags is css should be highlighted the same way as in html, not like a normal class (same color as universal selector *)
2. Countable values like px, rem, % etc. - assigned to a variable in mixins, do not have highlighting
3. The values assigned to the variable in mixins have the same highlighting as the css properties. I think it should have like a property value - dark orange
4. fyi: I don't really know if pseudo-classes shouldn't have the same color as normal properties ;)
5. Some css properties (like filter, mask, content etc.) have the same highlighting as classes

It's possible that a couple of things I've highlighted are features rather than a bugs ;D
Let me know what you think!