CSS Token System for a Cartography Studio

Problem/Feature Description

A professional cartography studio has finalized its visual direction with a designer: archival precision meets modern data science. The designer has handed off a brief (inputs/theme-brief.md) that documents the typography choices, color palette, composition approach, and motion intent. The studio is now ready to build.

The developer needs more than a brief — they need a CSS file they can actually use. The designer's decisions live in prose right now, and every time a developer implements a component they have to re-derive the same values from the brief. The team wants a canonical CSS token file that captures repeated design decisions in one place, plus clear rules for how future component authors should apply those values consistently without inventing local exceptions.

Read the brief at inputs/theme-brief.md and produce a complete, implementation-ready CSS token file. The file should make it easy for a developer to build any component without inventing new values or duplicating decisions. The studio's clients include professionals with accessibility needs — the implementation must account for this throughout, not as an afterthought.

Output Specification

Produce tokens.css and implementation-notes.md for a frontend developer. The CSS should be usable as the studio's source of truth, and the notes should explain how to extend the system without re-deriving values from the prose brief.