:root {
      --ink: #17263d;
      --muted: #627087;
      --paper: #f4f1e9;
      --card: rgba(255,255,255,.78);
      --line: rgba(23,38,61,.12);
      --teal: #0d8b82;
      --teal-dark: #07655f;
      --coral: #ef775c;
      --yellow: #f4c65e;
      --blue: #739fc9;
      --shadow: 0 18px 55px rgba(38,52,72,.11);
      --radius: 26px;
    }
    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      color: var(--ink);
      background:
        radial-gradient(circle at 9% 8%, rgba(244,198,94,.25), transparent 28rem),
        radial-gradient(circle at 92% 18%, rgba(13,139,130,.16), transparent 30rem),
        var(--paper);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.65;
    }
    a { color: inherit; text-decoration: none; }
    button { font: inherit; }
    .wrap { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
    .nav {
      position: sticky; top: 0; z-index: 20;
      backdrop-filter: blur(18px);
      background: rgba(244,241,233,.78);
      border-bottom: 1px solid rgba(23,38,61,.08);
    }
    .nav-inner { height: 70px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
    .brand { display: flex; align-items: center; gap: 11px; font-weight: 760; letter-spacing: .04em; }
    .brand-mark { width: 34px; height: 34px; border-radius: 50%; background: var(--ink); position: relative; box-shadow: inset 0 0 0 1px rgba(255,255,255,.15); }
    .brand-mark::before, .brand-mark::after { content: ""; position: absolute; border-radius: 50%; background: var(--yellow); }
    .brand-mark::before { width: 7px; height: 7px; left: 8px; top: 10px; box-shadow: 11px 7px 0 var(--coral); }
    .brand-mark::after { width: 4px; height: 4px; left: 16px; top: 7px; }
    .nav-links { display: flex; align-items: center; gap: 26px; color: var(--muted); font-size: 14px; }
    .nav-links a:hover { color: var(--teal-dark); }
    .status-pill { display: inline-flex; gap: 8px; align-items: center; padding: 8px 12px; background: rgba(13,139,130,.1); color: var(--teal-dark); border-radius: 999px; font-size: 13px; font-weight: 700; }
    .status-pill i { width: 7px; height: 7px; border-radius: 50%; background: var(--teal); box-shadow: 0 0 0 5px rgba(13,139,130,.1); }
    .hero { padding: 86px 0 54px; overflow: hidden; }
    .hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 56px; align-items: center; }
    .eyebrow { display: flex; align-items: center; gap: 10px; color: var(--teal-dark); font-size: 13px; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }
    .eyebrow::before { content: ""; width: 34px; height: 2px; background: var(--teal); }
    h1 { font-size: clamp(52px, 7vw, 86px); line-height: 1.02; letter-spacing: -.055em; margin: 24px 0 24px; }
    h1 span { color: var(--teal); position: relative; }
    .lead { font-size: clamp(18px, 2vw, 22px); color: #47566d; max-width: 690px; margin: 0; }
    .hero-actions { margin-top: 34px; display: flex; flex-wrap: wrap; gap: 13px; }
    .btn { border: 0; border-radius: 15px; padding: 13px 19px; cursor: pointer; display: inline-flex; align-items: center; gap: 9px; transition: transform .2s, box-shadow .2s, background .2s; }
    .btn:hover { transform: translateY(-2px); }
    .btn-primary { background: var(--ink); color: #fff; box-shadow: 0 10px 25px rgba(23,38,61,.2); }
    .btn-secondary { background: rgba(255,255,255,.72); color: var(--ink); border: 1px solid var(--line); }
    .microcopy { margin-top: 23px; color: var(--muted); font-size: 13px; display: flex; gap: 18px; flex-wrap: wrap; }
    .microcopy span::before { content: "✓"; color: var(--teal); font-weight: 800; margin-right: 7px; }
    .orbit-card { min-height: 500px; position: relative; display: grid; place-items: center; }
    .orbit-card::before { content: ""; position: absolute; inset: 7%; border: 1px dashed rgba(23,38,61,.18); border-radius: 50%; animation: spin 35s linear infinite; }
    .orbit-card::after { content: ""; position: absolute; inset: 20%; border: 1px solid rgba(13,139,130,.18); border-radius: 50%; }
    @keyframes spin { to { transform: rotate(360deg); } }
    .seed-core { width: 210px; aspect-ratio: 1; border-radius: 50%; background: var(--ink); color: #fff; display: grid; place-items: center; text-align: center; position: relative; z-index: 2; box-shadow: 0 30px 70px rgba(23,38,61,.25); }
    .seed-core strong { display: block; font-size: 28px; letter-spacing: -.03em; }
    .seed-core small { color: rgba(255,255,255,.66); }
    .node { position: absolute; z-index: 3; background: rgba(255,255,255,.88); border: 1px solid rgba(23,38,61,.08); border-radius: 17px; padding: 12px 15px; box-shadow: var(--shadow); font-size: 13px; font-weight: 720; }
    .node b { width: 9px; height: 9px; border-radius: 50%; display: inline-block; margin-right: 8px; }
    .n1 { top: 9%; left: 11%; } .n1 b { background: var(--coral); }
    .n2 { top: 20%; right: 2%; } .n2 b { background: var(--yellow); }
    .n3 { bottom: 16%; right: 6%; } .n3 b { background: var(--blue); }
    .n4 { bottom: 8%; left: 8%; } .n4 b { background: var(--teal); }
    .constellation { position: absolute; inset: 0; width: 100%; height: 100%; opacity: .55; }
    section { padding: 78px 0; }
    .section-head { display: flex; justify-content: space-between; gap: 30px; align-items: end; margin-bottom: 32px; }
    .section-head h2 { font-size: clamp(34px, 4.5vw, 54px); letter-spacing: -.045em; line-height: 1.08; margin: 7px 0 0; }
    .section-head p { max-width: 440px; color: var(--muted); margin: 0; }
    .demo-shell { background: #fff; border-radius: 32px; box-shadow: var(--shadow); border: 1px solid rgba(23,38,61,.08); overflow: hidden; }
    .demo-bar { height: 54px; display: flex; align-items: center; justify-content: space-between; padding: 0 22px; border-bottom: 1px solid var(--line); background: #fbfbf8; color: var(--muted); font-size: 13px; }
    .window-dots { display: flex; gap: 7px; }
    .window-dots i { width: 9px; height: 9px; border-radius: 50%; background: #e4e1d9; }
    .window-dots i:first-child { background: var(--coral); }
    .window-dots i:nth-child(2) { background: var(--yellow); }
    .window-dots i:nth-child(3) { background: var(--teal); }
    .demo-grid { display: grid; grid-template-columns: .9fr 1.1fr; min-height: 545px; }
    .seed-panel { background: #f7f5ef; padding: 28px; border-right: 1px solid var(--line); }
    .panel-label { font-size: 12px; color: var(--muted); font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
    .student-row { display: flex; align-items: center; gap: 14px; margin: 18px 0 25px; }
    .avatar { width: 52px; height: 52px; border-radius: 17px; background: linear-gradient(145deg, var(--yellow), var(--coral)); color: #fff; display: grid; place-items: center; font-weight: 850; font-size: 19px; }
    .student-row strong { display: block; font-size: 18px; }
    .student-row small { color: var(--muted); }
    .signal-group { margin-top: 21px; }
    .signal-group > strong { display: block; margin-bottom: 10px; font-size: 14px; }
    .tag-row { display: flex; flex-wrap: wrap; gap: 8px; }
    .tag { padding: 7px 10px; border-radius: 10px; background: #fff; border: 1px solid var(--line); color: #4d5b6f; font-size: 12px; }
    .tag.active { background: rgba(13,139,130,.1); border-color: rgba(13,139,130,.22); color: var(--teal-dark); }
    .meter { margin: 10px 0 17px; }
    .meter-top { display: flex; justify-content: space-between; font-size: 12px; color: var(--muted); }
    .track { height: 7px; background: #e7e4dc; border-radius: 999px; margin-top: 7px; overflow: hidden; }
    .track i { display: block; height: 100%; width: var(--w); background: var(--teal); border-radius: inherit; transition: width .4s ease; }
    .reaction-panel { padding: 30px; display: flex; flex-direction: column; }
    .signal-buttons { display: flex; flex-wrap: wrap; gap: 9px; margin: 17px 0 24px; }
    .signal-btn { border: 1px solid var(--line); background: #fff; color: var(--ink); padding: 9px 12px; border-radius: 11px; cursor: pointer; font-size: 13px; }
    .signal-btn:hover, .signal-btn.selected { border-color: var(--teal); background: rgba(13,139,130,.08); color: var(--teal-dark); }
    .message { background: #f7f8f8; border-radius: 18px; padding: 18px; color: #405068; border-left: 3px solid var(--teal); min-height: 82px; }
    .analysis-card { margin-top: 16px; border: 1px solid var(--line); border-radius: 18px; overflow: hidden; }
    .analysis-row { display: grid; grid-template-columns: 105px 1fr; gap: 14px; padding: 13px 16px; border-top: 1px solid var(--line); font-size: 13px; }
    .analysis-row:first-child { border-top: 0; }
    .analysis-row b { color: var(--muted); }
    .analysis-row span { color: #38485e; }
    .privacy-note { margin-top: auto; padding-top: 18px; color: var(--muted); font-size: 12px; }
    .privacy-note::before { content: "●"; color: var(--teal); margin-right: 7px; }
    .cap-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
    .cap { background: var(--card); border: 1px solid rgba(23,38,61,.08); border-radius: 22px; padding: 24px; min-height: 230px; transition: transform .2s, box-shadow .2s; }
    .cap:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
    .cap-num { color: var(--teal); font-size: 12px; font-weight: 850; letter-spacing: .14em; }
    .cap h3 { margin: 15px 0 9px; font-size: 21px; letter-spacing: -.02em; }
    .cap p { color: var(--muted); font-size: 14px; margin: 0; }
    .cap .mini { margin-top: 18px; color: var(--ink); font-size: 12px; font-weight: 700; }
    .flow { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0; background: var(--ink); color: #fff; border-radius: 28px; overflow: hidden; }
    .flow-step { padding: 27px 23px; min-height: 190px; position: relative; border-left: 1px solid rgba(255,255,255,.11); }
    .flow-step:first-child { border-left: 0; }
    .flow-step::after { content: "→"; position: absolute; right: -9px; top: 25px; color: var(--yellow); z-index: 2; font-size: 18px; }
    .flow-step:last-child::after { content: ""; }
    .flow-step small { color: var(--yellow); font-weight: 850; }
    .flow-step h3 { font-size: 18px; margin: 14px 0 8px; }
    .flow-step p { color: rgba(255,255,255,.62); margin: 0; font-size: 13px; }
    .case-card { background: #fff; border-radius: 30px; box-shadow: var(--shadow); padding: 34px; }
    .case-top { display: grid; grid-template-columns: 1fr auto; gap: 30px; align-items: start; }
    .case-top h3 { font-size: 30px; margin: 5px 0 10px; }
    .case-top p { color: var(--muted); margin: 0; max-width: 680px; }
    .score { border-radius: 18px; padding: 15px 20px; background: var(--ink); color: #fff; text-align: center; }
    .score strong { display: block; font-size: 30px; line-height: 1; }
    .score small { color: rgba(255,255,255,.62); }
    .timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 30px; }
    .time-card { background: #f7f5ef; border-radius: 17px; padding: 17px; border-top: 3px solid var(--blue); }
    .time-card:nth-child(2) { border-color: var(--yellow); }
    .time-card:nth-child(3) { border-color: var(--coral); }
    .time-card:nth-child(4) { border-color: var(--teal); }
    .time-card small { color: var(--muted); }
    .time-card strong { display: block; margin: 7px 0; }
    .time-card p { font-size: 12px; color: var(--muted); margin: 0; }
    .truth-box { margin-top: 20px; background: #fff3ee; color: #7d3e32; border: 1px solid rgba(239,119,92,.25); border-radius: 16px; padding: 15px 17px; font-size: 13px; }
    .truth-box strong { color: #612c22; }
    .boundary-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
    .boundary { border-radius: 24px; padding: 27px; }
    .boundary.done { background: rgba(13,139,130,.09); border: 1px solid rgba(13,139,130,.2); }
    .boundary.limit { background: rgba(244,198,94,.16); border: 1px solid rgba(203,153,42,.24); }
    .boundary h3 { margin-top: 0; }
    .check-list { list-style: none; padding: 0; margin: 16px 0 0; }
    .check-list li { position: relative; padding: 8px 0 8px 27px; color: #45536a; font-size: 14px; }
    .check-list li::before { position: absolute; left: 0; top: 8px; font-weight: 900; }
    .done .check-list li::before { content: "✓"; color: var(--teal); }
    .limit .check-list li::before { content: "→"; color: #b77b00; }
    footer { padding: 50px 0 70px; color: var(--muted); font-size: 13px; }
    .footer-inner { border-top: 1px solid var(--line); padding-top: 24px; display: flex; justify-content: space-between; gap: 20px; }
    @media (max-width: 900px) {
      .hero-grid, .demo-grid, .case-top { grid-template-columns: 1fr; }
      .orbit-card { min-height: 410px; }
      .seed-panel { border-right: 0; border-bottom: 1px solid var(--line); }
      .cap-grid { grid-template-columns: repeat(2, 1fr); }
      .flow { grid-template-columns: 1fr 1fr; }
      .flow-step { border-bottom: 1px solid rgba(255,255,255,.11); }
      .timeline { grid-template-columns: 1fr 1fr; }
      .boundary-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 620px) {
      .wrap { width: min(100% - 26px, 1180px); }
      .nav-links a { display: none; }
      .hero { padding-top: 58px; }
      .hero-grid { gap: 25px; }
      .orbit-card { min-height: 360px; transform: scale(.9); }
      section { padding: 58px 0; }
      .section-head { display: block; }
      .section-head p { margin-top: 14px; }
      .cap-grid, .flow, .timeline { grid-template-columns: 1fr; }
      .flow-step::after { content: "↓"; right: 22px; top: auto; bottom: -13px; }
      .analysis-row { grid-template-columns: 1fr; gap: 4px; }
      .footer-inner { display: block; }
    }
    @media (prefers-reduced-motion: reduce) {
      * { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
    }
  
.xinhai-demo-return {
  position: fixed;
  right: 18px;
  bottom: max(18px, env(safe-area-inset-bottom));
  z-index: 50;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 17px;
  border-radius: 999px;
  background: #17263d;
  color: #fff;
  box-shadow: 0 12px 32px rgba(23,38,61,.25);
  font-size: 13px;
  font-weight: 750;
}
.meter-value-initial { --w: 32%; }
.growth-input-form { margin-bottom: 26px; padding: 22px; border: 2px solid #0d756e; border-radius: 16px; background: #f1faf8; }
.growth-input-form h3 { margin: 0 0 10px; font-size: 1.25rem; }
.growth-input-form p { font-size: .875rem; line-height: 1.7; color: #475b60; }
.growth-input-form label { display: block; margin: 14px 0 7px; font-size: 1rem; font-weight: 700; }
.growth-input-form textarea, .growth-input-form select { width: 100%; min-width: 0; max-width: 100%; border: 1px solid #7d9c96; border-radius: 8px; background: white; color: #17263d; padding: 12px; font: inherit; font-size: 1rem; }
.growth-input-form textarea { resize: vertical; }
.growth-input-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.growth-input-actions button { min-height: 44px; padding: 10px 18px; border: 1px solid #0d756e; border-radius: 8px; background: #0d756e; color: white; font: inherit; font-weight: 700; cursor: pointer; }
.growth-input-actions button[type=button] { background: white; color: #075b55; }
.growth-input-form :focus-visible { outline: 3px solid #bc7518; outline-offset: 3px; }
.demo-grid.is-custom-input { grid-template-columns: 1fr; }
.demo-grid.is-custom-input .seed-panel, [hidden] { display: none !important; }
.message, .analysis-row span { overflow-wrap: anywhere; }
.signal-btn { min-height: 44px; font-size: .875rem; }
@media (max-width: 900px) { .reaction-panel { order: -1; min-width: 0; } .growth-input-form { padding: 16px; } }