:root{
  --ink:#33281e;
  --ink-2:#5c4b39;
  --muted:#8a7860;
  --accent:#7d9a46;
  --accent-2:#b07b3f;
  --line:rgba(120,95,65,.18);
  --card:rgba(255,252,246,.88);
  --shadow:0 18px 40px rgba(74,54,28,.16), 0 2px 6px rgba(74,54,28,.08);
}
*{box-sizing:border-box}
html,body{margin:0;height:100%;overflow:hidden}
body{
  font-family:"PingFang SC","Microsoft YaHei","Source Han Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  color:var(--ink);
  background:
    radial-gradient(1200px 800px at 22% 10%, #fffaf0 0%, rgba(255,250,240,0) 60%),
    radial-gradient(900px 700px at 84% 90%, #efdfc5 0%, rgba(239,223,197,0) 62%),
    linear-gradient(160deg,#fbf6ec 0%,#f4ebda 55%,#ebddc5 100%);
  -webkit-tap-highlight-color:transparent;
}

#scene{position:fixed;inset:0;width:100%;height:100%;display:block;touch-action:none;cursor:grab;z-index:1}
#scene:active{cursor:grabbing}

/* ---------- 标题 ---------- */
.hud{position:fixed;left:28px;top:22px;z-index:5;pointer-events:none;max-width:min(52vw,540px)}
.hud h1{margin:0;font-size:21px;letter-spacing:.02em;font-weight:700;display:flex;align-items:center;gap:9px}
.hud h1::before{content:"";width:9px;height:9px;border-radius:50%;background:var(--accent-2);flex:none;box-shadow:0 0 0 4px rgba(176,123,63,.16)}
.hud p{margin:7px 0 0;font-size:12.5px;color:var(--muted);letter-spacing:.04em}

/* ---------- 右上工具 ---------- */
.toolbar{position:fixed;right:24px;top:20px;z-index:6;display:flex;gap:8px}
.tool{
  display:inline-flex;align-items:center;gap:6px;
  border:1px solid var(--line);background:rgba(255,255,255,.66);color:var(--ink-2);
  padding:8px 12px;border-radius:999px;font-size:12.5px;cursor:pointer;font-family:inherit;
  backdrop-filter:blur(8px);transition:background .18s,color .18s,transform .12s;
}
.tool:hover{background:#fff}
.tool:active{transform:scale(.97)}
.tool.on{background:var(--ink);color:#fff5e6;border-color:transparent}
.tool .ico{font-size:13px;line-height:1}

/* ---------- 3D 标注 ---------- */
#labels{position:fixed;inset:0;z-index:3;pointer-events:none}
#leaders{position:absolute;inset:0;width:100%;height:100%;overflow:visible;pointer-events:none}
.lbl{
  position:absolute;transform:translate(-50%,-50%);
  display:inline-flex;align-items:center;gap:7px;
  border:1px solid rgba(120,95,65,.22);background:rgba(255,253,247,.93);color:#4a3826;
  padding:6px 12px;border-radius:999px;font-size:13px;font-weight:600;font-family:inherit;
  cursor:pointer;white-space:nowrap;line-height:1;
  box-shadow:0 6px 16px rgba(74,54,28,.13);
  transition:opacity .2s, transform .15s, background .15s;
  pointer-events:auto;
}
.lbl::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--accent-2);flex:none}
.lbl:hover{background:#fff;transform:translate(-50%,-50%) scale(1.05)}

/* ---------- 讲解卡片 ---------- */
.card{
  position:fixed;right:24px;top:86px;z-index:4;width:306px;
  max-height:calc(100vh - 210px);display:flex;flex-direction:column;
  background:var(--card);border:1px solid rgba(255,255,255,.72);border-radius:18px;
  box-shadow:var(--shadow);backdrop-filter:blur(16px);
  padding:14px 16px 12px;overflow:hidden;
  transition:max-height .26s ease;
}
.card.min{max-height:108px}
.card.min .chips,.card.min .card-body,.card.min .card-foot{display:none}
.card-head{display:flex;align-items:center;justify-content:space-between;gap:8px}
.card h2{margin:0;font-size:16px;font-weight:700}
.card-toggle{border:none;background:transparent;font-size:15px;color:var(--muted);cursor:pointer;padding:2px 4px;font-family:inherit;transition:transform .2s}
.card.min .card-toggle{transform:rotate(180deg)}
.chips{display:flex;flex-wrap:wrap;gap:5px;margin:11px 0 2px}
.chips button{
  border:1px solid var(--line);background:rgba(255,255,255,.55);color:var(--ink-2);
  font-size:11.5px;padding:4px 9px;border-radius:999px;cursor:pointer;font-family:inherit;transition:background .15s,color .15s;
}
.chips button:hover{background:#fff}
.chips button.on{background:var(--accent);color:#fff;border-color:transparent}
.card-body{overflow:auto;font-size:13px;line-height:1.74;color:#423325;margin-top:8px}
.card-body p{margin:0}
.card-body b{color:#2b2015;font-weight:700}
.card-body .tip{display:block;margin-top:9px;padding:7px 10px;border-radius:10px;background:rgba(125,154,70,.13);color:#4f6329;font-size:12px;line-height:1.62}
.card-foot{margin:11px 0 0;padding-top:9px;border-top:1px dashed var(--line);font-size:11.5px;color:var(--muted);line-height:1.6}

/* ---------- 底部步骤 ---------- */
.steps{
  position:fixed;left:50%;bottom:66px;transform:translateX(-50%);z-index:6;
  display:flex;gap:4px;background:rgba(255,253,247,.82);border:1px solid rgba(255,255,255,.85);
  border-radius:999px;padding:5px;box-shadow:var(--shadow);backdrop-filter:blur(12px);
}
.step{
  border:none;background:transparent;color:var(--ink-2);font-family:inherit;font-size:13px;
  padding:8px 14px;border-radius:999px;cursor:pointer;display:inline-flex;align-items:center;gap:7px;
  transition:background .18s,color .18s;white-space:nowrap;
}
.step i{
  font-style:normal;width:17px;height:17px;border-radius:50%;background:rgba(120,95,65,.14);color:#6b5540;
  font-size:11px;display:inline-flex;align-items:center;justify-content:center;flex:none;
}
.step.on{background:var(--ink);color:#fff6e8}
.step.on i{background:rgba(255,255,255,.22);color:#fff}
.hint{
  position:fixed;left:50%;bottom:30px;transform:translateX(-50%);z-index:5;margin:0;
  font-size:11.5px;color:var(--muted);letter-spacing:.05em;white-space:nowrap;
}

/* ---------- 加载 ---------- */
#loading{
  position:fixed;inset:0;z-index:20;display:flex;align-items:center;justify-content:center;
  background:#f8f2e6;color:var(--muted);font-size:14px;letter-spacing:.05em;
  transition:opacity .5s;
}
#loading.hide{opacity:0;pointer-events:none}

/* ---------- 手机 ---------- */
@media (max-width:760px){
  .hud{left:16px;top:13px;max-width:62vw}
  .hud h1{font-size:16.5px;gap:7px}
  .hud p{font-size:10.5px;margin-top:4px}
  .toolbar{right:10px;top:11px;gap:6px}
  .tool{padding:7px 9px;font-size:12px}
  .tool span:not(.ico){display:none}
  .card{left:10px;right:10px;top:auto;bottom:120px;width:auto;max-height:40vh;padding:12px 14px 10px;border-radius:16px}
  .card.min{max-height:100px}
  .card h2{font-size:15px}
  .card-body{font-size:12.5px}
  .steps{bottom:66px;gap:2px;padding:4px}
  .step{font-size:12px;padding:7px 10px;gap:5px}
  .step i{width:15px;height:15px;font-size:10px}
  .hint{bottom:36px;font-size:10.5px}
  .lbl{font-size:12px;padding:5px 10px}
}

/* ---------- 两个模型互链 ---------- */
.xlink{
  position:fixed;left:28px;top:80px;z-index:5;display:inline-flex;align-items:center;gap:6px;
  padding:6px 12px;border-radius:999px;background:rgba(255,255,255,.72);
  border:1px solid var(--line);color:var(--ink-2);font-size:12px;text-decoration:none;
  backdrop-filter:blur(8px);transition:background .15s,transform .12s;
}
.xlink:hover{background:#fff}
.xlink:active{transform:scale(.97)}
@media (max-width:760px){
  .xlink{left:16px;top:58px;font-size:11px;padding:5px 10px}
}