These values are the seed this system was derived from: styles.css, every page in this project and the guide in readme.md were built from them (the machine-readable copy is theme.json). If you retune the system by hand — palette, type, radii, spacing — do it in styles.css (the one place tokens live) and keep this page and theme.json in step so the record stays true. The data-theme-* attributes above mirror the ground / scheme / hue knobs for a future theme-controls surface; today they are documentation, nothing reads them.