/* Shared topic discovery remains available in the header and footer. */
.expanded-nav { gap: 24px; }
.learn-disclosure { position: relative; }
.learn-disclosure summary { display: flex; gap: 8px; align-items: center; min-height: 44px; font-size: 13px; cursor: pointer; list-style: none; }
.learn-disclosure summary::-webkit-details-marker { display: none; }
.disclosure-chevron { transition: transform .15s ease; }
.learn-disclosure[open] .disclosure-chevron { transform: rotate(180deg); }
.learn-disclosure summary:hover { color: var(--accent); }
.learn-panel { position: absolute; top: calc(100% + 8px); right: -190px; width: 560px; max-width: calc(100vw - 40px); padding: 24px; background: var(--paper, #f7f9fb); border: 1px solid var(--line); box-shadow: 0 16px 36px #192b3618; border-radius: 6px; z-index: 30; }
.learn-panel-label { font: 11px 'Fragment Mono', monospace; color: var(--muted); margin: 0 0 14px; }
.learn-topic-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 6px 12px; }
.site-header .site-nav .learn-topic-grid a { display: flex; flex-direction: column; align-items: flex-start; gap: 6px; padding: 12px; border-radius: 4px; white-space: normal; }
.learn-topic-grid a:hover { background: var(--wash); }
.learn-topic-grid small { color: var(--muted); font-size: 11px; line-height: 1.5; }
.site-nav .learn-setup { display: flex; justify-content: space-between; border-top: 1px solid var(--line); margin-top: 14px; padding: 14px 12px 0; }
.site-footer.expanded-footer { display: grid; grid-template-columns: 1.4fr 1fr .8fr; align-items: start; gap: 48px; padding-top: 40px; padding-bottom: 44px; }
.expanded-footer .footer-identity p { max-width: 260px; margin: 18px 0 24px; font-size: 13px; line-height: 1.7; color: var(--muted); }
.site-footer.expanded-footer nav { display: flex; flex-direction: column; gap: 2px; margin: 0; }
.expanded-footer nav h2 { font: 11px 'Fragment Mono', monospace; color: var(--muted); margin: 0 0 12px; }
.site-footer.expanded-footer nav a { font-size: 13px; min-height: 36px; }
@media (max-width: 1000px) { .site-header:has(.expanded-nav) { flex-wrap: wrap; gap: 8px; padding-block: 20px; } .site-header .expanded-nav { width: 100%; justify-content: space-between; gap: 12px; } .learn-panel { right: auto; left: -160px; } }
@media (max-width: 640px) {
  .site-header .expanded-nav { flex-wrap: wrap; justify-content: flex-start; column-gap: 22px; row-gap: 0; position: relative; }
  .learn-disclosure { position: static; }
  .learn-disclosure summary { font-size: 12px; }
  .learn-panel { top: 100%; left: 0; width: 100%; max-width: none; padding: 16px; }
  .learn-topic-grid { grid-template-columns: 1fr; gap: 0; }
  .site-header .site-nav .learn-topic-grid a { padding: 10px 8px; }
  .site-footer.expanded-footer { grid-template-columns: 1fr 1fr; gap: 28px 20px; }
  .expanded-footer .footer-identity { grid-column: 1 / -1; }
}
@media (prefers-reduced-motion: reduce) { .disclosure-chevron { transition: none; } }
.site-header .expanded-nav .learn-setup { display: flex; width: 100%; }
.learn-panel { max-height: min(70vh, 560px); overflow-y: auto; }
@media (max-width: 640px) { .site-footer.expanded-footer nav a { min-height: 44px; } }