diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..973a5ca
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,42 @@
+# Stage 1: Build frontend
+FROM node:20-alpine AS frontend-build
+
+WORKDIR /app/frontend
+
+COPY frontend/package.json frontend/package-lock.json ./
+RUN npm ci
+
+COPY frontend/ ./
+RUN npm run build
+
+# Stage 2: Production runtime
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    tini \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Python dependencies
+COPY backend/requirements.txt ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy backend source
+COPY backend/ ./
+
+# Copy built frontend from stage 1
+COPY --from=frontend-build /app/frontend/dist ./frontend/dist
+
+# Create data directories
+RUN mkdir -p /app/chroma_db /app/document_chunk /app/data /app/app/log
+
+# Expose port
+EXPOSE 8000
+
+# Use tini as init to handle signals properly
+ENTRYPOINT ["tini", "--"]
+
+# Start uvicorn
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..446ab43
--- /dev/null
+++ b/README.md
@@ -0,0 +1,125 @@
+# LegCo Reranker
+
+RAG-powered document Q&A app. Upload PDFs, ask questions in Cantonese, get bullet-point answers with citations.
+
+## Quick Start (Dev)
+
+```bash
+# Backend
+cd backend
+cp .env.example .env    # edit .env with your LLM API key
+pip install -r requirements.txt
+uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload
+
+# Frontend
+cd frontend
+npm install
+npm run dev
+```
+
+Backend → `http://localhost:8000` | Frontend → `http://localhost:5173`
+
+## Deploy with Docker
+
+### Prerequisites
+
+- Docker 24+ and Docker Compose v2
+- OpenRouter API key (or compatible LLM provider)
+
+### Setup
+
+```bash
+# 1. Configure environment
+cp backend/.env.example backend/.env
+# Edit backend/.env with your API keys and model names
+
+# 2. Build and start
+docker compose up -d --build
+
+# 3. Check health
+curl http://localhost:8000/health
+```
+
+The app is served at `http://localhost:8000` — both the API and the frontend UI.
+
+### Volumes
+
+| Volume | Purpose |
+|--------|---------|
+| `chroma_data` | ChromaDB vector store (persistent) |
+| `chunk_data` | Extracted PDF page files |
+| `sqlite_data` | Prompt templates and query history |
+
+### Environment Variables
+
+All configurable via `backend/.env`:
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `LLM_BASE_URL` | `https://openrouter.ai/api/v1` | LLM API endpoint |
+| `LLM_API_KEY` | — | API key for LLM provider |
+| `LLM_MODEL_NAME` | `qwen/qwen3.5-35b-a3b` | Chat model |
+| `EMBEDDING_MODEL` | `qwen/qwen3-embedding-4b` | Embedding model |
+| `EMBEDDING_API_KEY` | — | API key for embeddings (falls back to `LLM_API_KEY`) |
+| `RETRIEVAL_N_RESULTS` | `10` | Chunks per sub-question |
+| `RELEVANCE_THRESHOLD` | `7.0` | Min relevance score (0-10) |
+| `LLM_TIMEOUT` | `60.0` | LLM request timeout in seconds |
+
+### Production: Nginx Reverse Proxy
+
+```nginx
+# Include nginx.conf in your site config
+# Key settings:
+# - client_max_body_size 350M   (allow large PDF uploads)
+# - proxy_read_timeout 300s     (LLM calls can take minutes)
+```
+
+```bash
+# Install nginx
+sudo apt install nginx
+
+# Copy config
+sudo cp nginx.conf /etc/nginx/sites-available/legco
+sudo ln -s /etc/nginx/sites-available/legco /etc/nginx/sites-enabled/
+sudo nginx -t && sudo systemctl reload nginx
+```
+
+### Stopping
+
+```bash
+docker compose down
+```
+
+### Updating
+
+```bash
+git pull
+docker compose up -d --build
+```
+
+## Architecture
+
+```
+User → Nginx (80) → Uvicorn (8000)
+                         ├── FastAPI API (/api/v1/*)
+                         └── Static Frontend (/*)
+                              └── React 18 + Vite + Tailwind
+```
+
+### RAG Pipeline (Per-Sub-Question)
+
+```
+User Question
+  → [LLM] Decompose into 2-5 sub-questions
+  → [ChromaDB] Retrieve 10 chunks per sub-question
+  → [LLM] Score all chunks against their own sub-question (single call)
+  → [LLM] Generate markdown response per sub-question
+  → SSE stream with per-sub-question sources
+```
+
+## Notes
+
+- PDF upload limit: 300MB
+- Desktop only (not mobile-optimized)
+- No authentication (public demo)
+- All LLM calls routed through configurable base URL
diff --git a/backend/app/main.py b/backend/app/main.py
index 9717ead..bf8e62f 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -5,6 +5,7 @@ from pathlib import Path
 
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import FileResponse
 
 from app.routers import ingest, query, documents, prompts, history
 from app.core.config import get_settings
@@ -68,3 +69,12 @@ _history_conn.close()
 @app.get("/health")
 def health_check():
     return {"status": "ok"}
+
+_frontend_dist = Path(__file__).resolve().parent.parent / "frontend" / "dist"
+if _frontend_dist.is_dir():
+    @app.get("/{full_path:path}")
+    async def serve_frontend(full_path: str):
+        path = _frontend_dist / (full_path or "index.html")
+        if path.is_file():
+            return FileResponse(str(path))
+        return FileResponse(str(_frontend_dist / "index.html"))
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..92c69e0
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,26 @@
+version: "3.8"
+
+services:
+  app:
+    build: .
+    container_name: legco_reranker
+    ports:
+      - "8000:8000"
+    env_file:
+      - ./backend/.env
+    volumes:
+      - chroma_data:/app/chroma_db
+      - chunk_data:/app/document_chunk
+      - sqlite_data:/app/data
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8000/health"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 10s
+
+volumes:
+  chroma_data:
+  chunk_data:
+  sqlite_data:
diff --git a/nginx.conf b/nginx.conf
new file mode 100644
index 0000000..3b12a13
--- /dev/null
+++ b/nginx.conf
@@ -0,0 +1,18 @@
+server {
+    listen 80;
+    server_name _;
+
+    client_max_body_size 350M;
+
+    location / {
+        proxy_pass http://127.0.0.1:8000;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_read_timeout 300s;
+    }
+}