New concepts
Non-colour tokens (--space-*, --max, --radius, --bp-*, --motion) and reading them with var().
What changes after Naming?
Chapter 16 taught colour roles. Catalogs such as ui/navbars already ship a fuller token set. This chapter is the bridge.
Lessons
Related follow-on in Chapter 16: HTML→CSS custom-property data channel.
Checkpoint
Define a small :root scale for space, max-width, radius, and motion. Build one card that uses only those tokens for spacing and transition timing.