:root {
  /* https://primer.style/octicons/icon/link-external-16 */
  --icon-external-link: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path d="M10.604 1h4.146a.25.25 0 01.25.25v4.146a.25.25 0 01-.427.177L13.03 4.03 9.28 7.78a.75.75 0 01-1.06-1.06l3.75-3.75-1.543-1.543A.25.25 0 0110.604 1zM3.75 2A1.75 1.75 0 002 3.75v8.5c0 .966.784 1.75 1.75 1.75h8.5A1.75 1.75 0 0014 12.25v-3.5a.75.75 0 00-1.5 0v3.5a.25.25 0 01-.25.25h-8.5a.25.25 0 01-.25-.25v-8.5a.25.25 0 01.25-.25h3.5a.75.75 0 000-1.5h-3.5z"></path></svg>');
}

/* Mark external links as such in nav */
a.md-nav__link[href^="https:"]::after {
  -webkit-mask-image: var(--icon-external-link);
  mask-image: var(--icon-external-link);
  background: var(--md-default-fg-color);
  opacity: 0.6;
  height: 1em;
  width: 1em;
  margin-top: auto;
  margin-bottom: auto;
  content: ' ';
}