/* Persistent navigation; shared offsets keep secondary rails below the header. */
.brand-site { --site-header-height: 116px; }
.brand-site .site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  height: var(--site-header-height);
  background: #171719;
  border-bottom: 1px solid #b6a89426;
}
.brand-site :where(main[id], section[id]) { scroll-margin-top: calc(var(--site-header-height) + 24px); }
.brand-site .insights-bar,
.brand-site .chapter-nav { top: var(--site-header-height); }
.brand-site .approach-heading { top: calc(var(--site-header-height) + 32px); }
.brand-site .portrait-wrap,
.brand-site .about-story h2 { top: calc(var(--site-header-height) + 32px); }
.brand-site .brief-date time { top: calc(var(--site-header-height) + 100px); }
.brand-site :is(.phase, .ai-contact, .article-body h2, .article-body h3, .news-body .news-section-heading) {
  scroll-margin-top: calc(var(--site-header-height) + 100px);
}
.brand-site .case-chapter { scroll-margin-top: calc(var(--site-header-height) + 85px); }
@media (max-width: 760px) {
  .brand-site { --site-header-height: 90px; }
  .brand-site .mobile-nav {
    position: fixed;
    top: var(--site-header-height);
    z-index: 59;
    max-height: calc(100dvh - var(--site-header-height));
    overflow-y: auto;
    overscroll-behavior: contain;
  }
  .brand-site .approach-layout .approach-heading { top: var(--site-header-height); }
  .brand-site .approach-layout .phase {
    scroll-margin-top: calc(var(--site-header-height) + var(--phase-rail-height) + 24px);
  }
}