Nucleus CSS.
A polished, accessible CSS framework with 697 documented classes and zero runtime JavaScript.
npm install @navitallabs/nucleus-cssClasses
Tokens
Components
Runtime JS
Nucleus started as the shared CSS foundation for LeadScrapper Pro and Itiner. It's public because a framework only stays honest about 'no invented classes' if the manifest it's checked against is available for anyone to read, not just used internally.
Nucleus publishes llms.txt, a full class reference, and a JSON manifest alongside the human documentation. `npx @navitallabs/nucleus-css ai-setup <tool>` writes the right project rules for Claude Code, Codex, Cursor, or Antigravity, so a coding assistant uses the framework correctly from the first prompt instead of guessing.
A CLI validator (`npx @navitallabs/nucleus-css validate ./src`) checks a project's markup against the manifest and flags anything that isn't a real Nucleus class.
Layout primitives (grid, stack, cluster, split), a full component set (alerts, tables, navigation, avatars, feedback), accessible forms, and utilities for spacing, type, and color, every class prefixed `n-` so it never collides with application CSS. Version 2.0.0, semantically versioned so pinning a version in production is safe.