/* Appearance and language controls live in the top bar. Both palettes come from the
   tokens in styles.css, so dark mode needs only a few surface-specific adjustments. */
:root {
  color-scheme: light;
}
html[data-theme='dark'] {
  color-scheme: dark;
}
.theme-control {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: none;
}
.theme-control label {
  font: 500 10px var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--subtle);
}
.theme-control select {
  min-height: 36px;
  width: 112px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  padding: 6px 8px 6px 12px;
  background-color: var(--white);
  color: var(--ink);
  font: 500 12px var(--sans);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
}
.theme-control select:hover {
  border-color: var(--subtle);
}

/* Language switch: a two-state segmented control beside the appearance setting. */
.breadcrumb .breadcrumb-root {
  padding: 0;
  color: inherit;
}
.language-control {
  display: flex;
  flex: none;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  background: var(--surface-raised);
}
.language-control button {
  min-height: 30px;
  min-width: 36px;
  padding: 0 9px;
  border: none;
  border-radius: 6px;
  background: none;
  color: var(--muted);
  font: 600 11px var(--mono);
  letter-spacing: 0.06em;
  cursor: pointer;
  transition:
    background 0.15s,
    color 0.15s;
}
.language-control button[aria-pressed='true'] {
  background: var(--white);
  color: var(--green);
  box-shadow: var(--shadow-sm);
}
.language-control button:hover:not([aria-pressed='true']) {
  color: var(--ink);
}
.language-control button:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 0;
}
.resources .resources-note {
  display: block;
  margin-top: 8px;
  font-size: 12px;
}

/* Dark mode: a deeper navigation rail and code wells that stay distinct from cards. */
html[data-theme='dark'] .sidebar {
  background: #0d1321;
}
html[data-theme='dark'] .search-form kbd {
  background: var(--surface-raised);
}
html[data-theme='dark'] .language-control button[aria-pressed='true'] {
  background: var(--surface-hover);
  color: var(--primary-strong);
}
html[data-theme='dark'] .project-brief,
html[data-theme='dark'] .diagnostic-result {
  border: 1px solid var(--line);
}
html[data-theme='dark'] .lesson-card.done {
  background: linear-gradient(180deg, var(--emerald-soft), var(--white) 70%);
}

/* Keep search and a labeled appearance setting available at every viewport. */
@media (min-width: 651px) and (max-width: 1000px) {
  .topbar {
    min-height: 104px;
    height: auto;
    padding-block: 12px;
    flex-wrap: wrap;
    gap: 10px 14px;
  }
  .breadcrumb {
    flex-basis: 100%;
  }
  .search-form {
    margin-left: 0;
    flex: 1;
  }
}
@media (max-width: 650px) {
  /* The top bar shrinks to the brand and scrolls away; the bottom bar takes over. */
  .topbar {
    position: relative;
    height: auto;
    padding: calc(env(safe-area-inset-top) + 14px) 16px 14px;
    background: var(--white);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
  .topbar-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.02em;
    color: var(--ink);
  }
  .topbar-brand .brand-mark {
    width: 28px;
    height: 28px;
  }
  .breadcrumb,
  .search-form {
    display: none;
  }
  /* Search opens as a floating field at the top, clear of the on-screen keyboard. */
  html.search-open .search-form {
    display: flex;
    position: fixed;
    top: calc(env(safe-area-inset-top) + 12px);
    left: 12px;
    right: 12px;
    z-index: 46;
    height: 48px;
    margin: 0;
    background: var(--white);
    box-shadow: var(--shadow-lg);
  }
  .search-form input {
    font-size: 16px;
  }
}