server {
    listen 80;
    server_name _;

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

    # Proxy API requests to backend service
    location /api {
        proxy_pass http://backend:8000;
        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;
    }

    # Cache static assets with content hash (JS, CSS) indefinitely
    location ~* \.(js|css)$ {
        try_files $uri =404;
        add_header Cache-Control "public, max-age=31536000, immutable";
    }

    # SPA routing - index.html must never be cached
    location / {
        try_files $uri $uri/ /index.html;
        add_header Cache-Control "no-cache, no-store, must-revalidate";
    }
}