server {
    listen 8080 http2; # HTTP/2 for efficient multiplexing
    listen 8080 quic reuseport; # HTTP/3 support
    http3_max_concurrent_streams 128;

    # Root directory for content
    root /usr/share/nginx/html;
    index index.html;

    # Server name (adjust as needed)
    server_name yourdomain.com www.yourdomain.com;

    # Security headers
    add_header X-Frame-Options "DENY" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "no-referrer" always;
    add_header Permissions-Policy "geolocation=(), microphone=(), camera=(), payment=()" always;

    # Content Security Policy (CSP) for js, css, and html only
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' https://trusted.cdn.com https://metrics.nixc.us; style-src 'self' 'unsafe-inline' https://trusted.cdn.com; connect-src 'self' https://metrics.nixc.us; frame-src 'self';";

    # Caching headers for JavaScript and CSS files
    location ~* \.(js|css|html)$ {
        expires 1y;
        add_header Cache-Control "public, max-age=31536000, immutable";
    }

    # Rate limiting to prevent abuse
    limit_req_zone $binary_remote_addr zone=default:10m rate=20r/s;
    limit_req_status 429;

    location / {
        limit_req zone=default burst=30;
        try_files $uri $uri/ =404;
    }

    # HTTP/3 advertisement header
    add_header Alt-Svc 'h3-29=":8080"; ma=86400';  # Advertise HTTP/3 to clients
}