[Meta] CSS Nesting

[black7375]

Description

Suggestions for better nesting and referencing.

Related RFC

https://github.com/mincho-js/working-group/blob/main/text/001-css-nesting.md

Task or issue list

• [x] 1. Simple Attribute Selectors
  • [x] #14
• [x] 2. Nested Properties
  • [x] #18
  • [x] #23
• [x] 3. Property based condition
  • [x] #20
  • [x] #22
• [x] 4. Nested Selectors
  • [x] #24
  • [x] #26
• [x] 5. Nested At-Rules
  • [x] #25
  • [x] #26
• [x] 6. Property Reference (WIP) #46
  • [x] #47
• [x] #50

Additional context

Others

• 21