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

  add_header X-Content-Type-Options "nosniff" always;
  add_header Referrer-Policy "strict-origin-when-cross-origin" always;
  add_header Cache-Control "public, max-age=300";

  location = /healthz {
    access_log off;
    try_files /healthz =200;
  }

  location / {
    try_files $uri $uri/ =404;
  }

  error_page 404 /404.html;

  # NOTE: an add_header inside a location drops ALL server-level add_headers, so each block below
  # repeats the security headers.

  # Content-hashed file names (Astro bundles, scripts/optimize-images.mjs output): a changed file
  # gets a new URL, so these can be cached forever.
  location ~* ^/(?:_astro|assets/opt)/ {
    try_files $uri =404;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Cache-Control "public, max-age=31536000, immutable";
  }

  # Other static files keep a fixed URL when replaced (favicon, original JPEGs, logo), so cache
  # them for a week, not forever.
  location ~* \.(?:css|js|jpg|jpeg|png|webp|avif|svg|ico|woff2)$ {
    try_files $uri =404;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Cache-Control "public, max-age=604800";
  }
}