.geometry-main { --geo-purple: #696281; }
.geometry-intro { display: flex; gap: 32px; align-items: center; justify-content: space-between; margin-block: 44px 30px; }
.geometry-intro h1 { font-size: clamp(2rem, 4vw, 3.3rem); }
.geometry-intro .lead { max-width: 760px; margin-top: 14px; font-size: 1.05rem; }
.geometry-count { flex: 0 0 auto; display: flex; gap: 14px; align-items: center; color: var(--accent-dark); }
.geometry-count strong { font: 600 3.4rem var(--font-display); }
.geometry-count span { font-size: .8rem; line-height: 1.5; }
.geometry-workspace { margin-block: 0 54px; }
.geometry-toolbar { display: flex; align-items: center; gap: 10px; margin-bottom: 18px; }
.geometry-search { flex: 1; display: flex; align-items: center; min-width: 0; gap: 10px; padding: 11px 16px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
.geometry-search svg { width: 20px; height: 20px; fill: none; stroke: var(--muted); stroke-width: 1.7; flex-shrink: 0; }
.geometry-search input { width: 100%; min-width: 0; border: 0; outline: 0; background: transparent; font-size: .9rem; color: var(--ink); }
.geometry-search:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.geometry-control { background: var(--surface); border: 1px solid var(--line); color: var(--accent-dark); font-size: .8rem; padding: 12px 15px; border-radius: 12px; cursor: pointer; white-space: nowrap; }
.geometry-control:hover, .geometry-control[aria-pressed="true"] { background: var(--surface-green); border-color: var(--accent); }
.geometry-split { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(330px, 1fr); align-items: start; gap: 22px; }
.geometry-map-shell { border: 1px solid var(--line); background: var(--surface); border-radius: 18px; overflow: hidden; }
.geometry-map-top { display: flex; justify-content: space-between; gap: 12px; align-items: center; padding: 15px 18px; border-bottom: 1px solid var(--line); }
.geometry-map-top span { display: flex; align-items: center; gap: 8px; font-size: .85rem; font-weight: 600; }
.geometry-map-top i { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); }
.geometry-map-top small { color: var(--muted); font-size: .72rem; }
.geometry-map-scroll { height: 575px; overflow: auto; overscroll-behavior: contain; background: radial-gradient(circle, #dfe4de .7px, transparent .7px) 0 0 / 22px 22px; scrollbar-width: thin; scrollbar-color: #b5c5ba #f3f5f1; }
.geometry-map { position: relative; width: max-content; min-width: 100%; min-height: 100%; padding: 28px; display: flex; align-items: center; }
.geometry-map-scroll { cursor: grab; }
.geometry-map-scroll.is-panning, .geometry-map-scroll.is-panning * { cursor: grabbing; user-select: none; }
#geometry-connections { position: absolute; left: 0; top: 0; width: 100%; height: 100%; pointer-events: none; }
#geometry-connections path { fill: none; stroke: #9eb6aa; stroke-width: 1.4; }
.map-list { list-style: none; margin: 0; padding: 0; }
.map-item { display: flex; align-items: center; gap: 42px; }
.map-children { display: flex; flex-direction: column; gap: 12px; }
.map-node { position: relative; z-index: 1; display: flex; align-items: center; justify-content: space-between; gap: 8px; width: 178px; min-height: 46px; padding: 11px 13px; background: var(--surface-green); color: var(--accent-dark); border: 1px solid #cfddd3; border-radius: 10px; text-align: left; font-size: .78rem; line-height: 1.4; cursor: pointer; flex: 0 0 auto; }
.map-node:hover { border-color: var(--accent); background: var(--accent-soft); }
.map-node:focus-visible, .geometry-control:focus-visible, .geometry-detail button:focus-visible { outline: 3px solid #c0d5c6; outline-offset: 3px; }
.map-node[aria-expanded="true"] { background: var(--accent-dark); color: #fff; border-color: var(--accent-dark); }
.map-node.root { width: 153px; background: var(--geo-purple); border-color: var(--geo-purple); color: #fff; font-weight: 600; }
.map-node.leaf { width: 207px; background: #fff; color: var(--ink); border-color: var(--line); }
.map-node.leaf.selected { border-color: var(--accent); color: var(--accent-dark); background: var(--surface-green); box-shadow: 0 0 0 2px var(--accent-soft); }
.map-node.advanced { border-style: dashed; }
.map-node-count { font-size: .65rem; border-radius: 6px; padding: 2px 5px; background: rgba(100,130,113,.1); flex: 0 0 auto; }
.map-node[aria-expanded="true"] .map-node-count { background: rgba(255,255,255,.13); }
.map-node-arrow { font-size: 1rem; opacity: .75; }
.geometry-map-hint { margin: 0; padding: 12px 18px; color: var(--muted); font-size: .72rem; border-top: 1px solid var(--line); }
.geometry-detail { position: sticky; top: 18px; border: 1px solid var(--line); background: var(--surface); border-radius: 18px; padding: 24px; min-width: 0; }
.geometry-detail-empty { padding: 24px 0; }
.geometry-empty-icon { display: block; color: var(--accent); font-size: 4rem; line-height: 1; margin-bottom: 22px; }
.geometry-detail-empty h2 { font-size: 1.6rem; margin-bottom: 14px; }
.geometry-detail-empty p { color: var(--muted); font-size: .9rem; }
.geometry-detail-empty ol { padding-left: 20px; color: var(--muted); font-size: .83rem; margin: 22px 0; }
.geometry-detail-empty button, .geometry-back { background: var(--surface-green); color: var(--accent-dark); border: 0; border-radius: 8px; padding: 10px 12px; font-size: .8rem; cursor: pointer; }
.geometry-back { margin-bottom: 18px; }
.theorem-path { color: var(--muted); font-size: .7rem; line-height: 1.5; margin-bottom: 10px; }
.theorem-card h2 { font-size: 1.55rem; }
.theorem-card h3 { font: 600 .77rem var(--font-body); color: var(--accent); letter-spacing: .04em; margin: 20px 0 7px; }
.theorem-card p { font-size: .87rem; line-height: 1.65; }
.theorem-card .theorem-path { font-size: .7rem; }
.theorem-level { display: inline-block; font-size: .68rem; margin-top: 10px; padding: 4px 8px; border-radius: 5px; background: #f1edf5; color: var(--geo-purple); }
.theorem-diagram { margin: 20px 0 8px; padding: 15px 8px 10px; background: #fafbf8; border: 1px solid #edf0e8; border-radius: 10px; }
.theorem-diagram img { width: 100%; height: 210px; object-fit: contain; }
.theorem-diagram figcaption { margin-top: 10px; font-size: .65rem; color: var(--muted); text-align: center; }
.theorem-formula { background: var(--surface-green); border-radius: 10px; padding: 14px 10px; overflow-x: auto; }
.theorem-formula img { max-width: 100%; width: auto; height: auto; min-height: 24px; max-height: 120px; margin-inline: auto; }
.theorem-card .theorem-notation { color: var(--muted); font-size: .8rem; }
.theorem-note { padding: 12px; background: #f7f2e8; border-radius: 8px; margin-top: 18px; }
.theorem-note strong { font-size: .75rem; color: #776044; }
.theorem-note p { font-size: .77rem; margin-top: 4px; }
.theorem-card .theorem-source { margin-top: 20px; padding-top: 12px; border-top: 1px solid var(--line); color: var(--muted); font-size: .66rem; }
.theorem-permalink { display: inline-block; font-size: .73rem; margin-top: 12px; }
.geometry-search-results { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 8px; padding: 14px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); margin-bottom: 18px; }
.geometry-search-results button { display: block; text-align: left; min-width: 0; padding: 10px 12px; background: var(--surface-green); border: 0; border-radius: 8px; color: var(--accent-dark); font-size: .8rem; cursor: pointer; }
.geometry-search-results small { display: block; color: var(--muted); font-size: .67rem; margin-top: 3px; }
.geometry-search-results p { grid-column: 1/-1; font-size: .85rem; color: var(--muted); }
.geometry-reference { max-width: 900px; margin-inline: auto; }
.geometry-reference-intro { color: var(--muted); font-size: .9rem; margin-bottom: 22px; }
.reference-section { margin: 26px 0; }
.reference-section > h2 { font-size: 1.5rem; margin-bottom: 18px; }
.reference-section > h3 { font: 600 .9rem var(--font-body); margin: 20px 0 9px; color: var(--accent-dark); }
.reference-item { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; margin-bottom: 7px; }
.reference-item > summary { cursor: pointer; padding: 12px 16px; font-size: .9rem; }
.reference-item .theorem-card { padding: 8px 22px 22px; }
.reference-item .theorem-diagram img { height: 260px; }
.reference-item .theorem-formula { max-width: 620px; }
.geometry-about { display: grid; grid-template-columns: 1.1fr 1fr; gap: 50px; padding: 28px 0; border-top: 1px solid var(--line); margin-block: 45px; }
.geometry-about h2 { font-size: 1.65rem; margin-bottom: 15px; }
.geometry-about h3 { margin-bottom: 12px; }
.geometry-about p { color: var(--muted); font-size: .86rem; margin-top: 12px; }
.geometry-page .final-cta { margin-block: 35px 60px; }
.geometry-page .visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
@media (max-width: 1200px) and (min-width: 901px) {
  .geometry-page .nav { gap: 12px; }
  .geometry-page .nav a { font-size: .77rem; }
  .geometry-page .header-inner { gap: 16px; }
  .geometry-page .brand { font-size: 1.08rem; }
}
@media (max-width: 1050px) {
  .geometry-split { grid-template-columns: minmax(0,1.2fr) minmax(310px,1fr); gap: 16px; }
  .geometry-detail { padding: 20px; }
  .geometry-map-top { flex-wrap: wrap; }
}
@media (max-width: 760px) {
  .geometry-intro { margin-block: 30px 24px; gap: 14px; }
  .geometry-count { display: none; }
  .geometry-intro .lead { font-size: .9rem; }
  .geometry-toolbar { flex-wrap: wrap; }
  .geometry-search { flex-basis: 100%; }
  .geometry-control { flex: 1; font-size: .73rem; padding: 10px; }
  .geometry-split { grid-template-columns: minmax(0,1fr); }
  .geometry-map-scroll { height: auto; max-height: 530px; }
  .geometry-map { width: 100%; padding: 16px; min-height: 0; align-items: flex-start; }
  #geometry-tree, .map-list, .map-item { width: 100%; }
  .map-item { flex-direction: column; align-items: stretch; gap: 8px; }
  .map-children { gap: 8px; padding-left: 14px; border-left: 1px solid #c4d6cb; margin-left: 10px; width: calc(100% - 10px); }
  .map-node, .map-node.root, .map-node.leaf { width: 100%; min-height: 44px; font-size: .78rem; }
  #geometry-connections { display: none; }
  .geometry-map-top { padding: 12px 16px; }
  .geometry-map-hint { padding: 10px 16px; }
  .geometry-detail { position: static; }
  .geometry-detail-empty { padding: 0; }
  .geometry-detail-empty ol { margin: 14px 0; }
  .geometry-empty-icon { font-size: 2.5rem; margin-bottom: 14px; }
  .geometry-detail-empty h2 { font-size: 1.35rem; }
  .geometry-search-results { grid-template-columns: 1fr; }
  .geometry-about { grid-template-columns: 1fr; gap: 20px; }
  .theorem-diagram img { height: 220px; }
  .reference-item .theorem-card { padding: 8px 16px 16px; }
}
.geometry-section-back {display:inline-block;margin-top:24px;color:var(--accent-dark);}