a.jingtao-nav-extra {
  position: relative;
}

a.jingtao-nav-extra::after {
  content: "";
  position: absolute;
  left: 0.35em;
  right: 0.35em;
  bottom: 0.15em;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, #38bdf8, #818cf8);
  opacity: 0.85;
}

html.dark a.jingtao-nav-extra::after,
body[theme-mode="dark"] a.jingtao-nav-extra::after {
  background: linear-gradient(90deg, #7dd3fc, #a5b4fc);
}