Design tokens are an API, not a stylesheet

A token is not a hex code. A token is a contract that says "this surface is the page background, and we have agreed to call it `brand.bg`. If we change `brand.bg` to a different hex tomorrow, every surface that calls itself the page background updates."

The team that treats tokens as a stylesheet ends up with brand-blue-1, brand-blue-2, brand-blue-3, brand-blue-darker, brand-blue-actually-darker. The team that treats tokens as an API ends up with semantic names that survive a redesign because the redesign just swaps the hex.

We name tokens by role, never by appearance. `brand.surface` not `brand.white`. `brand.fg-muted` not `brand.gray-500`. The hex moves; the role doesn't. That is what makes tokens an API.