.knowledge-guides { display: grid; gap: 16px; max-width: 900px; }
.knowledge-guide {
  border: 1px solid;
  border-color: #45556e #33435c #243147 #3c4f6c;
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}
.knowledge-guide > summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 23px;
  cursor: pointer;
}
.knowledge-guide > summary::-webkit-details-marker { display: none; }
.knowledge-guide > summary:focus-visible { outline: 2px solid var(--accent); outline-offset: -4px; border-radius: 22px; }
.knowledge-number { color: var(--warm); font-size: 1.25rem; font-variant-numeric: tabular-nums; }
.knowledge-summary { flex: 1; min-width: 0; }
.knowledge-summary h2 { font-size: 1.2rem; letter-spacing: -.02em; line-height: 1.35; }
.knowledge-summary > span { display: block; margin-top: 6px; color: var(--muted); font-size: .9375rem; line-height: 1.5; }
.knowledge-guide > summary > svg { flex: 0 0 22px; color: var(--accent); transition: transform .18s ease; }
.knowledge-guide[open] > summary > svg { transform: rotate(180deg); }
.knowledge-guide[open] { border-top-color: #6c85af; }
.knowledge-body { padding: 0 24px 24px; }
.knowledge-steps { margin: 0; padding: 18px 0 0 25px; border-top: 1px solid var(--line); }
.knowledge-steps li { padding-left: 7px; margin-bottom: 14px; font-size: 1rem; line-height: 1.75; }
.knowledge-steps li::marker { color: var(--accent); font-weight: 650; }
.knowledge-tip { border-left: 2px solid var(--warm); border-radius: 0 12px 12px 0; padding: 14px 17px; margin: 20px 0 16px; background: #223047; line-height: 1.65; font-size: 1rem; }
.knowledge-tip strong { display: block; color: var(--warm); margin-bottom: 4px; font-size: .875rem; }
.knowledge-narrative { margin: 0 0 22px; padding: 20px 0 0; border-top: 1px solid var(--line); }
.knowledge-narrative h3 { margin: 0 0 7px; color: var(--warm); font-size: 1rem; font-weight: 600; line-height: 1.5; }
.knowledge-narrative p { margin: 0; font-size: 1rem; line-height: 1.75; }
.knowledge-timeline { list-style: none; }
.knowledge-timeline > li { position: relative; margin-left: 6px; padding: 0 0 24px 24px; border-left: 1px solid var(--accent-border); }
.knowledge-timeline > li::before { content: ''; position: absolute; left: -5px; top: 6px; width: 9px; height: 9px; border-radius: 50%; background: var(--warm); box-shadow: 0 0 0 4px var(--surface); }
.knowledge-timeline > li:last-child { padding-bottom: 0; border-left-color: transparent; }
.knowledge-story { display: grid; gap: 22px; }
.knowledge-closing { margin: 0 0 22px; padding: 16px 18px; border-left: 2px solid var(--warm); border-radius: 0 12px 12px 0; background: #223047; font-size: 1.0625rem; line-height: 1.7; }
.knowledge-illustrated { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 20rem), 1fr)); gap: 24px; align-items: start; padding-top: 20px; margin-bottom: 22px; border-top: 1px solid var(--line); }
.knowledge-illustrated > div { min-width: 0; }
.knowledge-illustrated .knowledge-narrative { padding-top: 0; border-top: 0; margin-bottom: 0; }
.knowledge-history-images { display: grid; gap: 18px; min-width: 0; }
.knowledge-history-figure { margin: 0; border: 1px solid; border-color: #45556e #33435c #243147 #3c4f6c; border-radius: 16px; background: #111b2b; box-shadow: var(--shadow-card); overflow: hidden; }
.knowledge-history-picture { display: block; width: 100%; height: auto; }
.knowledge-history-figure figcaption { padding: 14px 16px 16px; }
.knowledge-history-figure figcaption > p { margin: 0; font-size: .9375rem; line-height: 1.6; }
.knowledge-history-figure figcaption > .knowledge-picture-credit { margin-top: 8px; font-size: .875rem; color: var(--muted); overflow-wrap: anywhere; }
.knowledge-picture-credit a { text-underline-offset: 3px; }
.knowledge-picture-fallback { padding: 22px 16px; margin: 0; color: var(--muted); }
.knowledge-history-figure [hidden] { display: none; }
.knowledge-source { font-size: .875rem; line-height: 1.6; color: var(--muted); overflow-wrap: anywhere; }
.knowledge-source a { text-underline-offset: 4px; }
.knowledge-comparison { margin: 0 0 22px; }
.knowledge-comparison table { width: 100%; border-collapse: collapse; table-layout: fixed; text-align: left; }
.knowledge-comparison caption { text-align: left; font-weight: 600; margin: 4px 0 14px; }
.knowledge-comparison th:first-child { width: 30%; }
.knowledge-comparison td, .knowledge-comparison th { padding: 15px 8px; border-bottom: 1px solid var(--line); font-size: 1rem; line-height: 1.65; vertical-align: top; overflow-wrap: anywhere; }
.knowledge-comparison thead th { font-size: .875rem; color: var(--muted); font-weight: 500; }
.knowledge-comparison tbody th { color: var(--accent); font-weight: 600; }
.knowledge-cut { display: block; width: 56px; height: 56px; margin-bottom: 8px; }
.knowledge-comparison .hint { margin-top: 10px; font-size: .875rem; }
.knowledge-media { margin: 0 0 24px; background: #111b2b; border: 1px solid var(--accent-border); border-radius: 18px; overflow: hidden; }
.knowledge-media-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; flex-wrap: wrap; padding: 16px 18px 0; font-size: .9375rem; font-weight: 600; }
.knowledge-view { color: var(--muted); font-size: .875rem; font-weight: 400; }
.knowledge-animation { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; object-fit: contain; }
.knowledge-media figcaption { padding: 16px 18px 18px; }
.knowledge-media-controls { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.knowledge-media-controls .btn { min-width: 108px; min-height: 44px; }
.knowledge-media-controls .hint { flex: 1 1 160px; font-size: .875rem; }
.knowledge-media-controls .btn[aria-pressed="true"] { border-color: var(--warm); color: var(--warm); }
.knowledge-media-steps { display: grid; gap: 8px; padding-left: 23px; margin: 18px 0 0; font-size: .9375rem; line-height: 1.6; }
.knowledge-media-steps li { padding-left: 4px; }
.knowledge-media-steps li::marker { color: var(--accent); font-weight: 600; }
.knowledge-media-error { margin-top: 12px; }
.knowledge-media [hidden] { display: none; }
@media (max-width: 760px) {
  .mobile-nav { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .topbar .avatar { display: flex; width: 44px; height: 44px; min-width: 44px; }
  .topbar .top-actions { gap: 8px; }
  .knowledge-guide > summary { padding: 20px 17px; gap: 12px; }
  .knowledge-body { padding: 0 18px 20px; }
  .knowledge-summary h2 { font-size: 1.125rem; }
}
@media (max-width: 420px) {
  .topbar .brand-place { display: none; }
  .topbar .brand-name { font-size: 1rem; }
  .topbar .brand { gap: 6px; }
  .topbar { padding-left: 12px; padding-right: 12px; }
  .knowledge-comparison th:first-child { width: 34%; }
}
@media (prefers-reduced-motion: reduce) { .knowledge-guide > summary > svg { transition: none; } }