/* The hero owns learning links; the masthead only holds the letter and preferences. */
body > .sidebar {
  min-height: 60px;
  padding-block: 7px;
  flex-wrap: nowrap;
  gap: 24px;
  border-bottom: 1px solid color-mix(in srgb, var(--line) 45%, transparent);
}
:is(.sidebar, .page-header) .brand {
  flex: none;
  gap: 10px;
  font-size: 25px;
  line-height: 1.15;
  letter-spacing: 3px;
}

:is(.sidebar, .page-header) .brand .logo,
:is(.sidebar, .page-header) .brand .logo img {
  width: 32px;
  height: 32px;
}
:is(.sidebar, .page-header) .header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 14px;
  min-width: 0;
}
:is(.sidebar, .page-header) .header-letter,
:is(.sidebar, .page-header) .nav-letter-short {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--red);
  font: 500 14px/1.4 var(--reading-font, system-ui);
  white-space: nowrap;
}
:is(.sidebar, .page-header) .header-letter::before {
  content: "";
  width: 5px;
  height: 5px;
  margin-right: 8px;
  border-radius: 50%;
  background: currentColor;
}
:is(.sidebar, .page-header) .header-letter:hover,
:is(.sidebar, .page-header) .nav-letter-short:hover {
  text-decoration: underline;
  text-underline-offset: 5px;
}
:is(.sidebar, .page-header) .nav-letter-short {
  display: none;
}
:is(.sidebar, .page-header) .header-actions .theme-toggle {
  width: 44px;
  height: 44px;
  padding: 0;
  flex: none;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--ink);
}
:is(.sidebar, .page-header) .theme-toggle [data-theme-label] {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

:is(.sidebar, .page-header) .header-actions .theme-toggle {
  order: 2;
}
:is(.sidebar, .page-header) .language-picker {
  position: relative;
  flex: none;
}
:is(.sidebar, .page-header) .language-trigger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 44px;
  padding: 8px 10px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font: 500 13px/1.4 var(--reading-font, system-ui);
}
.language-chevron {
  display: inline-block;
  flex: none;
  width: 6px;
  height: 6px;
  margin-left: 2px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: translateY(-2px) rotate(45deg);
  opacity: 0.7;
}
.language-trigger[aria-expanded="true"] .language-chevron {
  transform: translateY(2px) rotate(225deg);
}
:is(.sidebar, .page-header) .theme-toggle:hover,
:is(.sidebar, .page-header) .language-trigger:hover,
:is(.sidebar, .page-header) .language-trigger[aria-expanded="true"] {
  background: color-mix(in srgb, var(--ink) 6%, transparent);
}
.sidebar {
  position: relative;
  z-index: 25;
}
:is(.sidebar, .page-header) .language-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px;
  width: 244px;
  max-width: calc(100vw - 28px);
  max-height: calc(100dvh - 84px);
  overflow-y: auto;
  padding: 8px;
  border: 1px solid color-mix(in srgb, var(--line) 35%, transparent);
  border-radius: 12px;
  background: var(--paper);
  box-shadow: 0 12px 32px #122c4020;
}
:is(.sidebar, .page-header) .language-menu button {
  min-height: 44px;
  padding: 10px 12px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--ink);
  text-align: left;
  font: 400 13px/1.4 var(--reading-font, system-ui);
}
:is(.sidebar, .page-header) .language-menu button:hover {
  background: color-mix(in srgb, var(--ink) 6%, transparent);
}
:is(.sidebar, .page-header) .language-menu button[aria-checked="true"] {
  color: var(--red);
  background: color-mix(in srgb, var(--red) 8%, transparent);
  font-weight: 600;
}
.sidebar :is(button, a):focus:not(:focus-visible) {
  outline: none;
}
.sidebar :is(button, a):focus-visible {
  outline: 2px solid var(--line);
  outline-offset: 2px;
}
@media (max-width: 760px) {
  body > .sidebar {
    min-height: 60px;
    padding: 7px 14px;
    gap: 10px;
  }
  :is(.sidebar, .page-header) .brand {
    gap: 7px;
    font-size: 23px;
  }
  :is(.sidebar, .page-header) .brand .logo,
  :is(.sidebar, .page-header) .brand .logo img {
    width: 28px;
    height: 28px;
  }
  :is(.sidebar, .page-header) .header-actions {
    gap: 3px;
  }
  :is(.sidebar, .page-header) .header-letter {
    display: none;
  }
  :is(.sidebar, .page-header) .nav-letter-short {
    display: inline-flex;
    padding: 6px;
    font-size: 13px;
  }
}
@media (max-width: 360px) {
  :is(.sidebar, .page-header) .brand {
    font-size: 21px;
    letter-spacing: 1px;
  }
  :is(.sidebar, .page-header) .brand .logo,
  :is(.sidebar, .page-header) .brand .logo img {
    width: 24px;
    height: 24px;
  }
  :is(.sidebar, .page-header) .header-actions .theme-toggle {
    width: 36px;
  }
}