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+# Código0 Nuevo
+
+## What This Is
+
+A refactored, modernized version of the original Código0 application - a comprehensive medical reference tool for emergency medical services. The project separates frontend (React/Vite), backend (Node.js/Express), and promotional site into a modular architecture while preserving the original clinical functionality.
+
+## Core Value
+
+Provide medical professionals with instant, reliable access to emergency protocols, drug information, and clinical calculators in a fast, offline-capable web application.
+
+## Requirements
+
+### Validated
+
+- ✓ Modular architecture with separate frontend/backend — existing
+- ✓ React/Vite frontend with TailwindCSS — existing
+- ✓ Node.js/Express backend with REST API — existing
+- ✓ Telephone protocols backend endpoint — existing
+- ✓ Clinical pages migrated (RCP, Ictus, Shock, Via Aerea, etc.) — existing
+- ✓ Layout components (Header, Footer, BottomNav, etc.) — existing
+- ✓ Protocol viewer system with Markdown support — existing
+
+### Active
+
+- [ ] Complete backend API integration for all frontend pages
+- [ ] Implement remaining pages (Ajustes, Galeria)
+- [ ] Add PWA service worker for offline capability
+- [ ] Implement calculators in Herramientas page
+- [ ] Evaluate and implement alternative protocol presentation options (CMS, Docusaurus, specialized viewer)
+- [ ] Connect frontend to backend API (replace mocked data)
+
+### Out of Scope
+
+- Deployment to local environment — user has VPS, local-only development
+- Mobile app (web-first approach)
+- Real-time features
+- Complex global state management (keep simple for now)
+
+## Context
+
+This is a brownfield project refactoring an existing medical reference application. The original código0 was a full-stack React/Express app with a specific clinical directory structure. The new version aims to:
+
+1. Separate concerns into clear modules (frontend, backend, promo site)
+2. Keep build/deploy scripts outside the app in `/scripts`
+3. Evaluate multiple protocol presentation methods
+4. Maintain the original clinical functionality and data structure
+
+The project uses Bun for package management, TailwindCSS for styling, and TypeScript for type safety.
+
+## Constraints
+
+- **Architecture**: Modular monorepo with frontend-backend separation
+- **Frontend**: React 18, Vite, TailwindCSS, React Router DOM
+- **Backend**: Node.js, Express, TypeScript
+- **Protocol Data**: JSON-like objects with steps, warnings, variations
+- **Development**: Local-only, no deployment to local environment
+- **State Management**: Simple local state (no complex global libraries)
+
+## Key Decisions
+
+| Decision | Rationale | Outcome |
+|----------|-----------|---------|
+| Separate frontend/backend into different folders | Clear separation of concerns, independent deployment | — Pending |
+| Keep scripts in `/scripts` directory | Keep main repository clean, easy to find dev tools | — Pending |
+| Use Markdown/MDX for protocol content | Simple, version-controllable, easy to edit | — Pending |
+| Evaluate multiple protocol presentation options | Find best fit for medical protocol display | — Pending |
+| No complex global state management | Keep it simple until needed | — Pending |
+| Local-only development | User has VPS, doesn't want local deployment | — Pending |
+
+---
+*Last updated: 2026-03-13 after initialization*