/* System UI stack — no custom webfonts.
   San Francisco on Apple, Segoe UI on Windows, Roboto on Android. */
:root {
  --serif: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}