impeccable-deterministic-zero-llm-design-scanner-pattern
npx impeccable provides a 3,590-line JS detection engine with 25 rules (13 AI slop tells + 12 general quality) at zero LLM token cost. Correct integration pattern: wire as PostToolUse hook on Write/Edit to .html/.css/.tsx/.jsx/.svelte/.astro files running npx impeccable detect --json <file>. Key rules include: 22-font rejection list (Inter, Roboto, Poppins etc.), OKLCH-first color enforcement, glassmorphism detection, card-in-card nesting, identical border-radius, gradient text, centered-everything layout.