Every product team has a style guide. Six months in, the web team's components look one way, the iOS team has quietly diverged, the Android team is tracking a third set of design decisions, and the "single source of truth" has become three parallel versions of partial truth. The team knows this and has tried every fix — ran a design-system sprint, nominated a component steward, froze the Figma library. Drift resumes within a quarter.

The problem is not discipline. The problem is that style guides built for human upkeep cannot keep pace with the number of screens, variants, and platform-specific implementations a real product ships.…