Generate a project-specific web design reference sheet (docs/design/design-reference.md) and companion enforcement skill for any website codebase. Extracts CSS custom properties, validates against a JSON schema scratchpad, inspects components, and produces a 12-section document covering colours, typography, spacing, layout, borders, shadows, motion, accessibility, dark mode, and Figma sync notes. Use when starting a new project, onboarding a design system, creating a Figma reference sheet, porting design tokens, or auditing existing styles. Triggers on: create a design reference, generate a style guide, document the design tokens, make a brand reference sheet, port design tokens, audit existing styles.