/* sections.css — content sections (T11): M3 structure zones + diagram,
   M4 fact cards, M7 source list + disclaimer, per-section error placeholder,
   one-shot entrance animation.
   Grid breakpoints are mobile-first (design-spec 3.2): 1 column base,
   2 columns >= 768px, 3 columns >= 1280px (card grid itself in layout.css).
   Motion rules live only inside the no-preference media (design-spec 5.3). */

/* ---- M3: structure layout (diagram + zone list) ---- */

.structure-layout {
  display: grid;
  gap: var(--gs-space-5);
  margin-top: var(--gs-space-5);
}

.structure-figure {
  margin: 0;
}

.structure-diagram {
  width: 100%;
  height: auto;
}

.structure-zones {
  display: grid;
  gap: var(--gs-space-4);
  align-content: start;
}

.structure-zone {
  padding: var(--gs-space-5);
  background-color: var(--gs-color-surface);
  border: 1px solid var(--gs-color-border);
  border-radius: var(--gs-card-radius);
}

.structure-zone-title {
  display: flex;
  align-items: center;
  gap: var(--gs-space-2);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
}

/* Numbered badge mirrors the diagram annotation and the "order" data field */
.structure-zone-index {
  display: inline-grid;
  place-items: center;
  min-width: 24px;
  height: 24px;
  color: var(--gs-color-accent-purple);
  font-family: var(--gs-font-display);
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
  background-color: var(--gs-color-surface-hover);
  border: 1px solid var(--gs-color-border-strong);
  border-radius: 999px;
}

.structure-zone-text {
  margin-top: var(--gs-space-3);
  color: var(--gs-color-text-secondary);
}

/* ---- External source links (M3 zones / M4 cards / M7 list, design-spec 4.1) ---- */

.source-link {
  display: inline-flex;
  align-items: center;
  gap: var(--gs-space-1);
  /* Oversized hit area via symmetric padding + negative margins (44px touch
     target, design-spec section 6) without shifting the surrounding layout. */
  padding-block: 12px;
  margin-block: -12px;
  color: var(--gs-color-accent-blue);
  font-size: 0.8125rem;
}

.source-link-arrow {
  font-size: 0.75em;
}

/* ---- M4: fact cards (design-spec 4.1) ---- */

.card {
  display: flex;
  flex-direction: column;
  gap: var(--gs-space-3);
  padding: var(--gs-space-5);
  background-color: var(--gs-color-surface);
  border: 1px solid var(--gs-color-border);
  border-radius: var(--gs-card-radius);
}

.card-title {
  color: var(--gs-color-text-primary);
}

.card-text {
  color: var(--gs-color-text-secondary);
}

.card-source {
  margin-top: auto;
  padding-top: var(--gs-space-2);
  border-top: 1px solid var(--gs-color-border);
}

/* ---- M7: source list + disclaimer ---- */

.source-list {
  display: grid;
  gap: var(--gs-space-4);
  margin-top: var(--gs-space-5);
}

.source-item {
  padding: var(--gs-space-4) var(--gs-space-5);
  background-color: var(--gs-color-surface);
  border: 1px solid var(--gs-color-border);
  border-radius: var(--gs-card-radius);
}

.source-item-title {
  display: inline-block;
  /* Oversized hit area (44px touch target) via padding + negative margins. */
  padding-block: 10px;
  margin-block: -10px;
  font-weight: 600;
}

.source-item-title:hover {
  text-decoration: underline;
}

.source-item-desc {
  margin-top: var(--gs-space-2);
  color: var(--gs-color-text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
}

.source-item-org {
  margin-top: var(--gs-space-2);
  color: var(--gs-color-text-tertiary);
}

.sources-disclaimer-box {
  margin-top: var(--gs-space-5);
  padding: var(--gs-space-4) var(--gs-space-5);
  background-color: var(--gs-color-bg-elevated);
  border: 1px solid var(--gs-color-border);
  border-left: 3px solid var(--gs-color-accent-gold);
  border-radius: 8px;
}

.sources-disclaimer-title {
  font-size: 1rem;
  font-weight: 600;
}

.sources-disclaimer-text {
  margin-top: var(--gs-space-2);
  color: var(--gs-color-text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
}

/* ---- Per-section error placeholder (flows.md exception table, T11) ---- */

.content-error {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--gs-space-3);
  margin-top: var(--gs-space-5);
  padding: var(--gs-space-4) var(--gs-space-5);
  background-color: var(--gs-color-surface);
  border: 1px solid var(--gs-color-border-strong);
  border-left: 3px solid var(--gs-color-danger);
  border-radius: 8px;
}

.content-error-text {
  color: var(--gs-color-text-secondary);
  font-size: 0.875rem;
}

.content-error-retry {
  padding: var(--gs-space-3) var(--gs-space-4); /* 44px hit area (design-spec 6) */
  color: var(--gs-color-bg);
  font-size: 0.875rem;
  background-color: var(--gs-color-accent-blue);
  border: 0;
  border-radius: 6px;
  cursor: pointer;
}

.content-error-retry:hover {
  background-color: var(--gs-color-focus);
}

/* Hover color change (no motion) also applies under reduced motion */
.card:hover {
  background-color: var(--gs-color-surface-hover);
}

/* ---- One-shot entrance animation + card hover motion (design-spec 5.2:
   opacity/transform only, all inside no-preference; reduced-motion users get
   the content directly visible — nothing outside this media query hides or
   moves anything) ---- */

@media (prefers-reduced-motion: no-preference) {
  .gs-reveal {
    opacity: 0;
    transform: translateY(16px);
    transition:
      opacity var(--gs-duration-slow) var(--gs-ease-out),
      transform var(--gs-duration-slow) var(--gs-ease-out);
  }

  .gs-reveal.gs-in-view {
    opacity: 1;
    transform: none;
  }

  .card {
    transition:
      background-color var(--gs-duration-fast) var(--gs-ease-standard),
      transform var(--gs-duration-fast) var(--gs-ease-standard),
      box-shadow var(--gs-duration-fast) var(--gs-ease-standard);
  }

  .card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgb(0 0 0 / 40%);
  }
}

/* ---- Tablet breakpoint: >= 768 (design-spec 3.2) ---- */

@media (width >= 768px) {
  .structure-layout {
    grid-template-columns: minmax(0, 2fr) minmax(0, 3fr);
    align-items: start;
  }

  .structure-figure {
    position: sticky;
    top: calc(var(--gs-scroll-margin-top) + var(--gs-space-4));
  }

  .source-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ---- Desktop breakpoint: >= 1280 (design-spec 3.2) ---- */

@media (width >= 1280px) {
  .source-list {
    gap: var(--gs-space-5);
  }
}