Create, update, apply, and validate a repository's DESIGN.md, the token-and-prose file that is a repository's living source of truth for its visual identity. Use when building or restyling UI, components, layouts, colors, typography, spacing, or themes in a repository that has, or should have, a DESIGN.md, including using its tokens and identity to guide external visual assets such as a logo or marketing material that need to stay on-brand. Use when starting a design system for a repository, when defining or changing design tokens that DESIGN.md should record, or when reading DESIGN.md and keeping it in sync with the implemented UI.
2026-07-20