A public design system (oklch tokens, CSS primitives, a Tailwind preset) extracted from eight of my projects. A script evaluates the WCAG contrast budget over 8 themes x 2 grounds, 814 assertions (text at 4.5:1, graphics at 3:1), and fails CI on any regression, proving the ratios rather than asserting them. Stack: CSS, design tokens, oklch, Tailwind CSS, Node.js, GitHub Actions.