ai-agent-book/extras/lang-switcher.css

/* ── Custom language dropdown in the header bar ──────────── */

.lang-switcher {
  position: relative;
  display: inline-flex;
  flex-shrink: 0;
  margin-inline-start: 0.5rem;
}

.lang-select {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.3rem;
  min-height: 1.9rem;
  padding: 0.32rem 0.48rem;
  color: var(--fenix-ink, var(--md-default-fg-color));
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  cursor: pointer;
  font: inherit;
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  line-height: 1;
  white-space: nowrap;
  transition: background-color 0.15s ease, border-color 0.15s ease,
              color 0.15s ease;
}

.lang-select:hover,
.lang-select[aria-expanded="true"] {
  color: var(--fenix-link-hover, var(--md-accent-fg-color));
  background: var(--fenix-bg-soft, rgba(128, 128, 128, 0.08));
  border-color: var(--fenix-border, rgba(128, 128, 128, 0.25));
}

.lang-select:focus-visible {
  outline: 2px solid var(--fenix-link-hover, var(--md-accent-fg-color));
  outline-offset: 2px;
}

.lang-select__icon,
.lang-select__chevron {
  display: inline-flex;
  flex: 0 0 auto;
}

.lang-select__icon svg {
  width: 0.92rem;
  height: 0.92rem;
  fill: currentcolor;
}

.lang-select__chevron svg {
  width: 0.68rem;
  height: 0.68rem;
  fill: currentcolor;
  transition: transform 0.15s ease;
}

.lang-select[aria-expanded="true"] .lang-select__chevron svg {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  z-index: 20;
  inset-block-start: calc(100% + 0.42rem);
  inset-inline-end: 0;
  width: max-content;
  min-width: 11.5rem;
  max-height: min(25rem, calc(100vh - 4.5rem));
  overflow-y: auto;
  padding: 0.35rem;
  color: var(--fenix-ink, var(--md-default-fg-color));
  background: var(--fenix-bg, var(--md-default-bg-color));
  border: 1px solid var(--fenix-border, rgba(128, 128, 128, 0.25));
  border-radius: 8px;
  box-shadow: 0 12px 32px rgba(27, 31, 35, 0.14),
              0 2px 8px rgba(27, 31, 35, 0.08);
  animation: lang-menu-enter 0.14s ease-out;
}

.lang-menu[hidden] {
  display: none;
}

.lang-menu__option {
  display: grid;
  grid-template-columns: 0.8rem minmax(0, 1fr);
  align-items: center;
  gap: 0.48rem;
  width: 100%;
  padding: 0.48rem 0.58rem;
  color: inherit;
  background: transparent;
  border: 0;
  border-radius: 5px;
  cursor: pointer;
  font: inherit;
  font-size: 0.68rem;
  line-height: 1.35;
  text-align: start;
}

.lang-menu__option:hover,
.lang-menu__option:focus-visible {
  color: var(--fenix-link-hover, var(--md-accent-fg-color));
  background: var(--fenix-bg-soft, rgba(128, 128, 128, 0.08));
  outline: none;
}

.lang-menu__option[aria-checked="true"] {
  color: var(--fenix-link-hover, var(--md-accent-fg-color));
  background: rgba(66, 185, 131, 0.1);
  font-weight: 600;
}

.lang-menu__check {
  width: 0.55rem;
  height: 0.3rem;
  border-bottom: 2px solid currentcolor;
  border-left: 2px solid currentcolor;
  opacity: 0;
  transform: translateY(-0.08rem) rotate(-45deg);
}

.lang-menu__option[aria-checked="true"] .lang-menu__check {
  opacity: 1;
}

.lang-menu__label {
  white-space: nowrap;
}

[data-md-color-scheme="slate"] .lang-menu {
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.42),
              0 2px 8px rgba(0, 0, 0, 0.3);
}

@keyframes lang-menu-enter {
  from {
    opacity: 0;
    transform: translateY(-0.25rem) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@media (prefers-reduced-motion: reduce) {
  .lang-menu,
  .lang-select__chevron svg {
    animation: none;
    transition: none;
  }
}

@media screen and (max-width: 44.984375em) {
  .lang-switcher {
    margin-inline-start: 0.15rem;
  }

  .lang-select {
    width: 2rem;
    min-height: 2rem;
    padding: 0.4rem;
  }

  .lang-select__label,
  .lang-select__chevron {
    display: none;
  }
}