server {
    listen 3000;
    server_name _;
    root /usr/share/nginx/html;
    index index.html;

    # Serve client-metadata.json with correct Content-Type
    location = /client-metadata.json {
        add_header Access-Control-Allow-Origin *;
    }

    # SPA fallback
    location / {
        try_files $uri $uri/ /index.html;
    }

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

    # No cache for service worker
    location = /sw.js {
        add_header Cache-Control "no-store";
    }

    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml;
}