server {
    listen 80;
    server_name _;

    root /usr/share/nginx/html;
    index index.html;

    # Proxy API calls to the backend container
    location /api/ {
        proxy_pass         http://backend:3001;
        proxy_http_version 1.1;
        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 60s;
    }

    # React app — all other routes serve index.html (client-side routing)
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Security headers
    add_header X-Frame-Options        "SAMEORIGIN"   always;
    add_header X-Content-Type-Options "nosniff"      always;
    add_header Referrer-Policy        "strict-origin" always;

    # Cache static assets
    location ~* \.(js|css|png|svg|ico|woff2?)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
}