/*
 * 03-layout.css — page and shell structure
 * ---------------------------------------------------------------------------
 * Structural containers only: no colour decisions, no component styling.
 * ---------------------------------------------------------------------------
 */

/* ── Authenticated content area ───────────────────────────────────────────── */
.aura-page {
  padding: 2rem 2.5rem;
  max-width: 1200px;
}
@media (max-width: 768px) {
  .aura-page { padding: 1.5rem 1rem; }
}

/* ── App shell ────────────────────────────────────────────────────────────── */
.aura-shell        { display: flex; height: 100%; }
.aura-shell__main  { flex: 1 1 0%; min-width: 0; display: flex; flex-direction: column; overflow: hidden; }
.aura-shell__body  { flex: 1 1 0%; overflow-y: auto; }

.aura-sidebar {
  position: fixed;
  inset-block: 0;
  left: 0;
  z-index: 30;
  display: flex;
  flex-direction: column;
  width: var(--aura-sidebar-width);
  flex-shrink: 0;
  background: var(--aura-sidebar-bg);
  border-right: 1px solid var(--aura-sidebar-border);
  transition: transform 200ms var(--aura-ease);
}
@media (min-width: 1024px) {
  .aura-sidebar { position: relative; transform: none; }
}

/* ── Reading column ───────────────────────────────────────────────────────────
   Long-form lesson text. Capped at the measure token so lines stay in the
   45–75 character range; wider elements (video, quiz, nav) sit outside this. */
.aura-read {
  max-width: var(--aura-measure);
}

/* ── Simple responsive grid helper ────────────────────────────────────────── */
.aura-grid       { display: grid; gap: 1rem; }
.aura-grid--2    { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.aura-grid--3    { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.aura-grid--4    { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }

/* Wide content must scroll inside its own container, never the page body. */
.aura-scroll-x { overflow-x: auto; }