<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32">
  <!-- the fella mark: a lowercase "f" on the brand teal. No icon, no period. -->
  <rect x="0" y="0" width="32" height="32" rx="9" fill="#008080"/>
  <text x="16" y="23" text-anchor="middle"
        font-family="'Geist', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif"
        font-size="21" font-weight="600" letter-spacing="-1" fill="#ffffff">f</text>
</svg>
