/* Header group */
hgroup {
  padding: 0.25rem 0.5rem;
  border-left: 0.25rem solid currentColor;
  margin: 0 0 1rem;
}

hgroup > :is(h1, h2, h3, h4, h5, h6)[id] > a:hover::before {
  right: calc(100% + 1.25rem);
}

/* Headings */
h1,
h2,
h3,
h4,
h5,
h6 {
  border-bottom: 1px solid transparent;
  margin: 0 0 1rem;
  line-height: 1.25;
}

:not(:is(dialog, article, body) > header:first-child) > :is(h1, h2) {
  border-color: var(--bd-muted);
}

:not(hgroup, blockquote, header) > :is(h1, h2, h3, h4, h5, h6):first-child {
  margin-top: 1.5rem;
}

:is(h1, h2, h3, h4, h5, h6):last-child {
  margin-bottom: 0;
}

h1 {
  font-size: 2rem;
}

h2 {
  font-size: 1.5rem;
}

h3 {
  font-size: 1.25rem;
}

h4 {
  font-size: 1rem;
}

h5 {
  font-size: 0.875rem;
}

h6 {
  color: var(--muted);
  font-size: 0.85rem;
}

:is(h1, h2, h3, h4, h5, h6)[id] > a {
  position: relative;
  color: inherit;
}

:is(h1, h2, h3, h4, h5, h6)[id] > a:hover {
  text-decoration: none;
}

:is(h1, h2, h3, h4, h5, h6)[id] > a:hover::before {
  position: absolute;
  top: 0.125rem;
  right: calc(100% + 0.25rem);
  color: var(--muted);
  content: "#";
}

:is(h1, h2, h3, h4, h5, h6)[id]:has(> a:hover) {
  border-color: currentColor;
}