- Introduce FastNext Design System based on `shadcn/ui` and `Tailwind CSS 4`.
- Detail semantic color tokens using the OKLCH color space for better accessibility.
- Define typography, spacing, shadows, and border radius standards.
- Provide component usage guidelines for consistent and accessible design.
- Outline responsive design, performance, and accessibility best practices.
- Add dark mode implementation strategy and tooling references.
- Include a version history for change tracking and future updates.