server {
    listen       80;
    server_name  _;
    root         /usr/share/nginx/html;
    index        index.html;

    gzip            on;
    gzip_types      text/css application/javascript image/svg+xml;
    gzip_min_length 256;

    # Assets use stable filenames and we redeploy in place, so revalidate on
    # every load (cheap — tiny files, 304s) instead of caching for a week.
    # A week-long cache here means redeploys leave returning players on stale
    # CSS/JS until expiry; no-cache avoids that footgun.
    location ~* \.(css|js|svg|png|ico)$ {
        add_header X-Content-Type-Options "nosniff" always;
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header Referrer-Policy "no-referrer-when-downgrade" always;
        add_header Cache-Control "no-cache" always;
    }

    # HTML entry point: always revalidate so redeploys show up immediately.
    location / {
        add_header X-Content-Type-Options "nosniff" always;
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header Referrer-Policy "no-referrer-when-downgrade" always;
        add_header Cache-Control "no-cache" always;
        try_files $uri $uri/ /index.html;
    }
}