/* Source hierarchy, official supplements, and background references. */

.source-stack,
.official-supplement,
.optimization-supplement,
.source-lineage-attribution {
  margin: 4rem 0;
}

.source-stack-grid,
.supplement-grid,
.optimization-crosswalk,
.source-lineage-grid {
  display: grid;
  gap: 1rem;
}

.source-stack-grid,
.source-lineage-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.source-stack-card,
.supplement-card,
.optimization-crosswalk article,
.optimization-chapter-supplement,
.source-lineage-card {
  min-width: 0;
  padding: 1.25rem 1.35rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.source-stack-card.primary,
.supplement-card.official,
.optimization-chapter-supplement {
  border-left: 4px solid var(--accent);
}

.source-stack-role,
.supplement-source-id,
.lineage-role {
  display: block;
  margin-bottom: 0.45rem;
  color: var(--accent);
  font: 650 0.72rem var(--font-code);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.source-stack-card h3,
.supplement-card h3,
.optimization-crosswalk h3,
.optimization-chapter-supplement h2,
.source-lineage-card h3 {
  margin: 0.35rem 0 0.65rem;
}

.source-stack-card p,
.supplement-card p,
.optimization-crosswalk p,
.optimization-chapter-supplement p,
.source-lineage-card p {
  color: var(--muted);
}

.source-stack-card ul,
.supplement-card ul,
.source-lineage-card ul {
  margin-bottom: 0;
}

.supplement-header,
.optimization-supplement-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  align-items: end;
  margin-bottom: 1.5rem;
}

.supplement-header .section-heading,
.optimization-supplement-header .section-heading {
  margin-bottom: 0;
}

.supplement-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.supplement-page-link,
.lineage-source-link {
  display: inline-flex;
  margin-top: 0.5rem;
  font-weight: 650;
}

.optimization-crosswalk {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.optimization-crosswalk article > span {
  color: var(--accent);
  font: 650 0.72rem var(--font-code);
}

.optimization-chapter-supplement {
  margin: 2.5rem 0;
}

.source-hierarchy-note {
  padding: 1rem 1.15rem;
  border-left: 4px solid var(--accent);
  background: var(--surface-2);
}

.source-lineage-card.wide {
  grid-column: 1 / -1;
}

@media (max-width: 900px) {
  .source-stack-grid,
  .source-lineage-grid,
  .supplement-grid,
  .optimization-crosswalk {
    grid-template-columns: 1fr;
  }
}