Built a 48‑token design system on the platform's own glass material and wrote the linter that rejects a magic number, a hardcoded font size, or an animation that ignores the reduce‑motion preference.

Situation. An interface built by adding views accumulates values: a corner radius here, a fourteen‑point font there, a two‑tenths‑of‑a‑second animation somewhere else. Individually each is reasonable and collectively they are a design that cannot be changed, because there is no such thing as “the corner radius” to change — there are forty of them, slightly different, spread across fifty files.

Task. The visual vocabulary had to be reduced to a named set, expressed against the platform’s own material rather than reinvented, and defended by a check so it stays reduced.

Action. The system is forty‑eight tokens in six groups: spacing, typography, colour, radius, elevation and motion. Colour and material are built on the platform’s semantic colours and its glass material rather than fixed values, which is what makes the interface follow the system appearance, the accent colour and the contrast settings without any code that watches for them. Typography maps to the platform’s text styles so it scales with the user’s size preference instead of pinning a point value. The linter rejects three things: a numeric literal where a spacing or radius token belongs, a hardcoded font size anywhere, and an animation declared without honouring the reduce‑motion preference. The third is the one that would otherwise erode fastest, because an animation is added in a moment of polish and the preference check is the part that gets skipped — so the rule makes the animation itself impossible to write without it, rather than asking anyone to remember.

Result. Forty‑eight tokens describe the whole interface, the appearance follows the system, and none of the three erosions can be committed. The limit is that a token system constrains consistency and not quality — everything now matches, and matching is not the same as being well designed, which is a judgement no linter in this project makes.