/* Locked mobile chrome. Desktop keeps the left rail; phones use a bottom bar
 * + More sheet. Same structure on every hub — see MOBILE.md.
 */

.hub-mobile-nav {
  display: none;
}

.hub-more-sheet {
  margin: 0;
  padding: 0;
  border: 0;
  max-width: none;
  max-height: none;
  width: 100%;
  height: 100%;
  background: transparent;
  color: var(--ink);
}

.hub-more-sheet::backdrop {
  background: rgba(10, 21, 54, 0.35);
  backdrop-filter: blur(6px);
}

.hub-more-sheet__panel {
  position: fixed;
  inset: auto 0 0;
  z-index: 40;
  padding: var(--space-5) var(--space-4) calc(var(--space-5) + env(safe-area-inset-bottom, 0px));
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  background: var(--warm-white, #fbfaf5);
  box-shadow: 0 -1rem 3rem rgba(10, 21, 54, 0.14);
  max-height: min(85dvh, 40rem);
  overflow: auto;
}

.hub-more-sheet__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.hub-more-sheet__head h2 {
  margin: 0;
  font-family: var(--font-ui);
  font-size: var(--text-md);
  font-weight: var(--weight-bold);
  color: var(--depth, var(--navy));
}

.hub-more-sheet__close {
  min-height: 44px;
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--depth, var(--navy));
  background: rgba(255, 255, 255, 0.92);
  font-family: var(--font-ui);
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  cursor: pointer;
}

.hub-more-sheet__nav {
  display: grid;
  gap: var(--space-2);
}

.hub-more-sheet__section {
  margin: var(--space-3) 0 0;
  padding: 0 var(--space-1);
  font-family: var(--font-ui);
  font-size: var(--text-2xs);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-caps);
  text-transform: uppercase;
  color: var(--muted);
}

.hub-more-sheet__section:first-child {
  margin-top: 0;
}

.hub-more-sheet__nav a,
.hub-more-sheet__nav button {
  min-height: 48px;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin: 0;
  padding: var(--space-3) var(--space-4);
  border: 0;
  border-radius: var(--radius-md);
  color: var(--depth, var(--navy));
  background: rgba(255, 255, 255, 0.72);
  font-family: var(--font-ui);
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  text-align: left;
  text-decoration: none;
  cursor: pointer;
}

.hub-more-sheet__nav a:active,
.hub-more-sheet__nav button:active {
  background: rgba(55, 111, 183, 0.1);
}

.hub-more-sheet__glyph {
  display: grid;
  place-items: center;
  width: 1.125rem;
  height: 1.125rem;
  flex: 0 0 1.125rem;
  color: var(--muted);
}

.hub-more-sheet__glyph svg,
.hub-more-sheet__glyph img,
.hub-more-sheet__icon {
  width: 1.125rem;
  height: 1.125rem;
  display: block;
  object-fit: contain;
}

@media (max-width: 720px) {
  /* Canvas clears the fixed bottom bar. */
  .hub-layout,
  .hub-shell,
  .app-shell,
  .teacher-layout,
  .page-frame {
    padding-bottom: calc(5.5rem + env(safe-area-inset-bottom, 0px));
  }

  .hub-mobile-nav {
    position: fixed;
    z-index: 30;
    inset: auto 0 0;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--space-1);
    min-height: calc(4.65rem + env(safe-area-inset-bottom, 0px));
    margin: 0;
    padding: var(--space-2) var(--space-3) env(safe-area-inset-bottom, 0px);
    border-top: 1px solid rgba(255, 255, 255, 0.75);
    background: rgba(250, 248, 242, 0.92);
    box-shadow: 0 -1rem 3rem rgba(10, 21, 54, 0.08);
    backdrop-filter: blur(12px);
  }

  .hub-mobile-nav a,
  .hub-mobile-nav button {
    min-height: 44px;
    display: grid;
    place-items: center;
    align-content: center;
    gap: 0.2rem;
    margin: 0;
    padding: var(--space-1);
    border: 0;
    border-radius: var(--radius-sm);
    color: var(--muted);
    background: transparent;
    font-family: var(--font-ui);
    font-size: var(--text-2xs);
    font-weight: var(--weight-bold);
    text-decoration: none;
    cursor: pointer;
  }

  .hub-mobile-nav a[aria-current="page"],
  .hub-mobile-nav a.is-current,
  .hub-mobile-nav button[aria-current="page"],
  .hub-mobile-nav button.is-current,
  .hub-mobile-nav button.is-active {
    color: var(--depth, var(--navy));
    background: rgba(55, 111, 183, 0.08);
  }

  .hub-mobile-nav__glyph {
    width: 1.25rem;
    height: 1.25rem;
    color: inherit;
  }

  .hub-mobile-nav__glyph svg,
  .hub-mobile-nav__glyph img {
    width: 1.25rem;
    height: 1.25rem;
    display: block;
    object-fit: contain;
  }
}

@supports not (backdrop-filter: blur(1px)) {
  .hub-mobile-nav {
    background: #fff;
  }
}