:root{
  --bg:#f4f6fb; --card:#ffffff; --ink:#1e293b; --sub:#64748b;
  --line:#e6ebf2; --brand:#2563eb; --brand-soft:#eff6ff;
  --ok:#059669; --warn:#d97706; --red:#dc2626;
  --radius:14px;
  --shadow:0 1px 3px rgba(15,23,42,.06), 0 8px 24px rgba(15,23,42,.06);
}
*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{
  background:var(--bg); color:var(--ink);
  font:14px/1.65 "Microsoft YaHei","PingFang SC","Hiragino Sans GB",system-ui,sans-serif;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}

/* ---------- 顶栏 ---------- */
.top{background:var(--card);border-bottom:1px solid var(--line);padding:10px 18px 0;position:sticky;top:0;z-index:20}
.top-row{display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.logo{font-size:16px;font-weight:700;letter-spacing:.5px;display:flex;align-items:center;gap:8px}
.logo i{width:24px;height:24px;border-radius:7px;background:linear-gradient(135deg,#2563eb,#06b6d4);
  display:inline-block;color:#fff;font-style:normal;font-size:13px;line-height:24px;text-align:center}
.badge{font-size:12px;color:var(--sub);background:#f1f5f9;border-radius:999px;padding:2px 10px}
.home{font-size:13px;color:var(--brand)}
.chapters{display:flex;gap:4px;overflow-x:auto;padding:8px 0 0;flex-wrap:wrap}
.chapters a{font-size:13px;padding:6px 12px;border-radius:9px;color:var(--sub);white-space:nowrap}
.chapters a:hover{background:#f1f5f9}
.chapters a.on{background:var(--brand-soft);color:var(--brand);font-weight:600}

/* ---------- 布局 ---------- */
.app{display:grid;grid-template-columns:216px minmax(320px,1fr) 296px;gap:14px;padding:14px;align-items:start}
@media (max-width:1180px){ .app{grid-template-columns:190px 1fr} .panel{grid-column:1 / -1} }
@media (max-width:820px){ .app{grid-template-columns:1fr} .side{max-height:150px} }

.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow)}
.side{padding:8px;position:sticky;top:110px;max-height:calc(100vh - 130px);overflow:auto}
.side h4{margin:8px 10px 6px;font-size:12px;color:var(--sub);font-weight:600;letter-spacing:1px}
.side a{display:block;padding:8px 11px;border-radius:9px;font-size:13.5px;color:var(--ink);margin-bottom:2px}
.side a:hover{background:#f1f5f9}
.side a.on{background:var(--brand);color:#fff;font-weight:600}
.side a small{display:block;font-size:11.5px;opacity:.72;font-weight:400}

.stage-wrap{display:flex;flex-direction:column;gap:12px;min-width:0}
.canvas-card{position:relative;padding:10px;height:clamp(420px,62vh,620px)}
.canvas-card canvas{display:block;width:100%;height:100%;border-radius:8px;background:#fdfdff;cursor:crosshair;
  touch-action:none;-webkit-user-select:none;user-select:none}

/* ---------- 画布缩放工具条（触控友好：44px 大按钮） ---------- */
.zoombar{
  position:absolute;right:18px;bottom:18px;z-index:5;display:flex;align-items:center;gap:4px;
  background:rgba(255,255,255,.94);border:1px solid var(--line);border-radius:14px;
  box-shadow:0 2px 10px rgba(15,23,42,.14);padding:5px;
  -webkit-user-select:none;user-select:none;
}
.zoombar button{
  width:44px;height:44px;padding:0;font-size:22px;line-height:1;border-radius:11px;
  border:1px solid var(--line);background:#fff;color:#1e293b;
  touch-action:manipulation;display:flex;align-items:center;justify-content:center;
}
.zoombar button.mini{width:auto;min-width:44px;padding:0 12px;font-size:14px}
.zoombar button:hover{background:#f1f5f9}
.zoombar button:active{background:var(--brand);border-color:var(--brand);color:#fff}
.zoombar .zoomval{
  min-width:60px;text-align:center;font-size:14px;font-weight:700;color:var(--brand);
  font-variant-numeric:tabular-nums;
}
.zoombar.zoomed{border-color:var(--brand)}
.zoombar.zoomed .zoomval{color:var(--brand)}

/* 全屏演示（教室大屏） */
.canvas-card:fullscreen{height:100%;padding:0;background:#fff;display:block}
.canvas-card:fullscreen canvas{height:100%;width:100%;border-radius:0}
.canvas-card:fullscreen .zoombar{right:22px;bottom:22px;transform:scale(1.15);transform-origin:right bottom}
.canvas-card:-webkit-full-screen{height:100%;padding:0;background:#fff}
.canvas-card:-webkit-full-screen canvas{height:100%;width:100%;border-radius:0}
.stage-head{display:flex;justify-content:space-between;align-items:baseline;gap:10px;padding:2px 6px 0}
.stage-head h2{margin:0;font-size:16px}
.stage-head .no{font-size:12px;color:var(--sub)}
.tip{padding:12px 16px;font-size:13.2px;color:#475569;background:var(--card);border-radius:var(--radius);
  box-shadow:var(--shadow);border-left:4px solid var(--brand)}
.tip b{color:var(--ink)}
.tip .k{color:var(--brand);font-weight:600}

/* ---------- 参数面板 ---------- */
.panel{padding:12px 14px 16px;position:sticky;top:110px;max-height:calc(100vh - 130px);overflow:auto}
.panel h3{margin:0 0 4px;font-size:14px}
.panel .hint{font-size:12px;color:var(--sub);margin-bottom:10px}
.ctl{margin-bottom:11px}
.ctl-h{display:flex;justify-content:space-between;align-items:baseline;gap:6px;margin-bottom:3px}
.ctl-name{font-size:12.8px;color:#334155}
.ctl-val{font-size:12.5px;font-weight:700;color:var(--brand);font-variant-numeric:tabular-nums}
input[type=range]{width:100%;accent-color:var(--brand);height:20px;margin:0}
input[type=number],input[type=text],select{
  width:100%;padding:6px 8px;border:1px solid var(--line);border-radius:8px;font-size:13px;
  font-family:inherit;color:var(--ink);background:#fff;outline:none}
input[type=number]:focus,select:focus{border-color:var(--brand)}
.ctl-check{display:flex;align-items:center;gap:7px;font-size:13px;color:#334155;padding:2px 0}
.ctl-check input{accent-color:var(--brand);width:15px;height:15px}
.btns{display:flex;gap:6px;flex-wrap:wrap;margin:10px 0 4px}
button{padding:6px 12px;border-radius:9px;border:1px solid var(--line);background:#fff;color:#334155;
  font-size:13px;font-family:inherit;cursor:pointer}
button:hover{background:#f8fafc;border-color:#cbd5e1}
button.pri{background:var(--brand);border-color:var(--brand);color:#fff}
button.pri:hover{background:#1d4ed8}
.note{font-size:12.2px;color:var(--sub);line-height:1.6;background:#f8fafc;border-radius:9px;padding:8px 10px;margin:8px 0}
.divider{height:1px;background:var(--line);margin:12px 0}
.readout{background:#0f172a;color:#cbd5e1;border-radius:10px;padding:10px 12px;font:12.6px/1.7 "Cascadia Mono",Consolas,monospace;
  white-space:pre-wrap;margin-top:6px;max-height:220px;overflow:auto}
.readout b{color:#7dd3fc;font-weight:600}
.readout .g{color:#86efac}
.readout .r{color:#fca5a5}

/* ---------- 触摸屏（教学一体机）适配：控件加大 ---------- */
@media (pointer: coarse){
  .side a{padding:12px 13px;font-size:14.5px}
  .side a small{font-size:12.2px}
  button{min-height:44px;padding:8px 16px;font-size:14px}
  .zoombar button{width:52px;height:52px;font-size:26px}
  .zoombar button.mini{min-width:52px;font-size:15px}
  input[type=range]{height:30px}
  input[type=number],input[type=text],select{padding:10px 12px;font-size:14px}
  .ctl-check input{width:20px;height:20px}
  .chapters a{padding:9px 14px;font-size:14px}
}

/* ---------- 首页 ---------- */
.hero{padding:26px 22px 18px;text-align:center}
.hero h1{margin:0 0 6px;font-size:24px}
.hero p{margin:0;color:var(--sub);font-size:13.5px}
.wrap{max-width:1080px;margin:0 auto;padding:8px 18px 40px}
.ch-card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px 18px;margin-bottom:14px}
.ch-card h2{margin:0 0 2px;font-size:17px;display:flex;align-items:center;gap:9px}
.ch-card h2 span{font-size:12px;font-weight:400;color:var(--sub)}
.ch-card .desc{color:var(--sub);font-size:12.8px;margin:0 0 12px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(228px,1fr));gap:10px}
.grid a{display:block;border:1px solid var(--line);border-radius:11px;padding:10px 12px;font-size:13.4px;transition:.15s}
.grid a:hover{border-color:var(--brand);background:var(--brand-soft);transform:translateY(-1px)}
.grid a em{display:block;font-style:normal;font-size:11.6px;color:var(--sub);margin-top:2px}
.foot{text-align:center;color:var(--sub);font-size:12.5px;padding:10px 0 30px}