:root {
    --primary: #6C63FF;
    --primary-light: #8A84FF;
    --primary-dark: #4B44CC;
    --accent: #E94070;
    --accent2: #12B76A;
    --accent3: #9B51E0;
    --bg: #F7F8FC;
    --bg2: #EDEEF7;
    --bg3: #E4E5F0;
    --card: #FFFFFF;
    --card2: #F2F3FA;
    --border: rgba(108,99,255,0.15);
    --border2: rgba(0,0,0,0.07);
    --text: #1A1B2E;
    --text2: #4A4B6A;
    --text3: #8A8BA8;
    --success: #12B76A;
    --warning: #D97706;
    --danger: #E94070;
    --info: #0EA5E9;
    --shadow: 0 4px 24px rgba(108,99,255,0.1);
    --shadow-glow: 0 0 40px rgba(108,99,255,0.12);
    --radius: 16px;
    --radius-sm: 10px;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }
  @media print {
    :root {
      --bg: #fff; --bg2: #f8f9ff; --bg3: #f0f1ff;
      --card: #ffffff; --card2: #f5f5ff;
      --text: #1a1b2e; --text2: #4a4b6a; --text3: #8a8ba8;
      --border: rgba(108,99,255,0.2); --border2: rgba(0,0,0,0.07);
      --shadow: none; --shadow-glow: none;
    }
    body { background: #fff !important; }
    .page-break { page-break-before: always; }
    .section { break-inside: avoid; }
    .card { break-inside: avoid; }
  }
  html { scroll-behavior: smooth; }
  body { font-family: 'Inter', system-ui, sans-serif; background: var(--bg); color: var(--text); line-height: 1.7; font-size: 15px; }

  /* ── Cover ── */
  .cover {
    min-height: 100vh;
    background: radial-gradient(ellipse at 30% 20%, rgba(108,99,255,0.12) 0%, transparent 60%),
                radial-gradient(ellipse at 80% 80%, rgba(155,81,224,0.08) 0%, transparent 50%),
                linear-gradient(160deg, #f0f1ff 0%, #f7f8fc 60%, #fdf4ff 100%);
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    text-align: center; padding: 60px 40px; position: relative; overflow: hidden;
  }
  .cover-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: rgba(108,99,255,0.1); border: 1px solid rgba(108,99,255,0.3);
    border-radius: 100px; padding: 6px 18px; font-size: 12px; font-weight: 600;
    letter-spacing: 2px; text-transform: uppercase; color: var(--primary); margin-bottom: 32px;
  }
  .cover-badge::before { content: '◉'; font-size: 10px; animation: pulse 2s infinite; }
  @keyframes pulse { 0%,100%{opacity:1} 50%{opacity:0.4} }
  .cover h1 {
    font-size: clamp(36px, 5vw, 64px); font-weight: 900; line-height: 1.1; letter-spacing: -2px;
    background: linear-gradient(135deg, #3730a3 0%, var(--primary) 45%, var(--accent3) 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin-bottom: 16px;
  }
  .cover-sub { font-size: 20px; color: var(--text2); font-weight: 400; margin-bottom: 48px; max-width: 700px; }
  .cover-stats { display: flex; gap: 24px; flex-wrap: wrap; justify-content: center; margin-top: 48px; }
  .stat-pill {
    background: var(--card); border: 1px solid var(--border); border-radius: 100px;
    padding: 10px 24px; display: flex; align-items: center; gap: 10px;
    font-size: 13px; font-weight: 500; color: var(--text2);
    box-shadow: 0 2px 12px rgba(108,99,255,0.08);
  }
  .stat-pill strong { color: var(--primary); font-size: 15px; }
  .cover-meta { display: flex; gap: 40px; flex-wrap: wrap; justify-content: center; margin-top: 40px; }
  .cover-meta-item .label { font-size: 11px; font-weight: 600; letter-spacing: 1.5px; text-transform: uppercase; color: var(--text3); margin-bottom: 4px; }
  .cover-meta-item .value { font-size: 14px; color: var(--text2); font-weight: 500; }

  .container { max-width: 1100px; margin: 0 auto; padding: 0 40px; }

  /* ── TOC ── */
  .toc-section { background: var(--bg2); border-bottom: 1px solid var(--border2); padding: 60px 40px; }
  .toc-grid { max-width: 1100px; margin: 32px auto 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
  .toc-item {
    display: flex; align-items: flex-start; gap: 14px;
    background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius-sm);
    padding: 18px 20px; text-decoration: none; transition: all 0.2s; color: var(--text);
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  }
  .toc-item:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow-glow); }
  .toc-num { font-size: 11px; font-weight: 700; color: var(--primary); background: rgba(108,99,255,0.1); border-radius: 6px; padding: 4px 8px; flex-shrink: 0; }
  .toc-title { font-size: 13px; font-weight: 600; line-height: 1.4; }
  .toc-desc { font-size: 11px; color: var(--text3); margin-top: 4px; }

  /* ── Sections ── */
  .section { padding: 80px 0; border-bottom: 1px solid var(--border2); }
  .section:last-child { border-bottom: none; }
  .section-label { font-size: 11px; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; color: var(--primary); margin-bottom: 8px; }
  .section-header { display: flex; align-items: flex-start; gap: 20px; margin-bottom: 48px; }
  .section-number { font-size: 11px; font-weight: 700; color: var(--primary); background: rgba(108,99,255,0.1); border: 1px solid rgba(108,99,255,0.2); border-radius: 8px; padding: 6px 12px; white-space: nowrap; margin-top: 6px; }
  .section-title-wrap h2 { font-size: 32px; font-weight: 800; letter-spacing: -1px; line-height: 1.2; }
  .section-title-wrap p { font-size: 15px; color: var(--text2); margin-top: 8px; max-width: 700px; line-height: 1.6; }

  /* ── Cards ── */
  .card { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 28px; position: relative; overflow: hidden; box-shadow: 0 2px 12px rgba(0,0,0,0.04); }
  .card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px; background: linear-gradient(90deg, var(--primary) 0%, var(--accent3) 100%); opacity: 0; transition: opacity 0.3s; }
  .card:hover::before { opacity: 1; }
  .card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 20px; }
  .card-title { font-size: 16px; font-weight: 700; margin-bottom: 12px; display: flex; align-items: center; gap: 10px; }
  .card-icon { width: 36px; height: 36px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; }
  .card ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
  .card ul li { display: flex; align-items: flex-start; gap: 8px; font-size: 13px; color: var(--text2); line-height: 1.5; }
  .card ul li::before { content: '›'; color: var(--primary); font-weight: 700; flex-shrink: 0; }

  /* ── Highlights ── */
  .highlight { border-radius: var(--radius); padding: 24px 28px; margin: 24px 0; border-left: 3px solid; }
  .highlight.purple { background: rgba(108,99,255,0.06); border-color: var(--primary); }
  .highlight.green { background: rgba(18,183,106,0.06); border-color: var(--success); }
  .highlight.red { background: rgba(233,64,112,0.06); border-color: var(--danger); }
  .highlight.yellow { background: rgba(217,119,6,0.06); border-color: var(--warning); }
  .highlight.blue { background: rgba(14,165,233,0.06); border-color: var(--info); }
  .highlight-title { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 8px; }
  .highlight.purple .highlight-title { color: var(--primary); }
  .highlight.green .highlight-title { color: var(--success); }
  .highlight.red .highlight-title { color: var(--danger); }
  .highlight.yellow .highlight-title { color: var(--warning); }
  .highlight.blue .highlight-title { color: var(--info); }
  .highlight p { font-size: 13px; color: var(--text2); line-height: 1.6; }

  /* ── Vector grid ── */
  .vector-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; margin-top: 28px; }
  .vector-card {
    background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius-sm);
    padding: 20px; transition: all 0.2s; box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  }
  .vector-card:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow); }
  .vector-card-header { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
  .vector-icon { width: 36px; height: 36px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; }
  .vector-num { font-size: 10px; font-weight: 700; color: var(--text3); text-transform: uppercase; letter-spacing: 1px; }
  .vector-name { font-size: 14px; font-weight: 700; color: var(--text); }
  .vector-desc { font-size: 12px; color: var(--text2); line-height: 1.6; margin-bottom: 10px; }
  .vector-tags { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 10px; }
  .vector-tag { font-size: 10px; font-weight: 600; padding: 2px 8px; border-radius: 100px; background: var(--bg3); color: var(--text3); border: 1px solid var(--border2); }
  .vector-weight { margin-top: 10px; display: flex; align-items: center; gap: 8px; font-size: 11px; color: var(--text3); }
  .weight-bar { flex: 1; height: 3px; background: var(--bg3); border-radius: 2px; overflow: hidden; }
  .weight-fill { height: 100%; border-radius: 2px; }
  .vector-group-label {
    grid-column: 1 / -1; font-size: 12px; font-weight: 700; letter-spacing: 2px;
    text-transform: uppercase; color: var(--primary); padding: 16px 0 4px;
    border-top: 1px solid var(--border2); margin-top: 8px;
  }
  .vector-group-label:first-child { border-top: none; margin-top: 0; }

  /* ── Central diagram ── */
  .graph-container { background: linear-gradient(135deg, rgba(108,99,255,0.04) 0%, rgba(155,81,224,0.04) 100%); border: 1px solid var(--border); border-radius: var(--radius); padding: 40px; margin: 32px 0; text-align: center; position: relative; overflow: hidden; }
  .vd-center { width: 160px; height: 160px; border-radius: 50%; background: linear-gradient(135deg, rgba(108,99,255,0.12) 0%, rgba(155,81,224,0.08) 100%); border: 2px solid rgba(108,99,255,0.4); display: flex; align-items: center; justify-content: center; text-align: center; font-size: 12px; font-weight: 700; color: var(--primary); line-height: 1.4; position: relative; z-index: 2; }
  .vd-ring { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; max-width: 900px; }
  .vector-diagram { display: flex; flex-direction: column; align-items: center; gap: 20px; }
  .vd-node { background: var(--card); border: 1px solid var(--border2); border-radius: 100px; padding: 8px 18px; font-size: 12px; font-weight: 600; color: var(--text2); white-space: nowrap; transition: all 0.2s; }
  .vd-node.primary { border-color: var(--primary); color: var(--primary); background: rgba(108,99,255,0.07); }
  .vd-node.accent { border-color: var(--accent); color: #b8204e; background: rgba(233,64,112,0.07); }
  .vd-node.green { border-color: var(--success); color: #0a6641; background: rgba(18,183,106,0.07); }
  .vd-node.violet { border-color: var(--accent3); color: #6b2fa0; background: rgba(155,81,224,0.07); }

  /* ── Tables ── */
  .table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border2); box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
  table { width: 100%; border-collapse: collapse; font-size: 13px; }
  thead { background: var(--card2); }
  th { padding: 14px 18px; text-align: left; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: var(--text3); border-bottom: 1px solid var(--border2); }
  td { padding: 14px 18px; color: var(--text2); border-bottom: 1px solid var(--border2); vertical-align: top; line-height: 1.5; }
  tr:last-child td { border-bottom: none; }
  tr:hover td { background: rgba(108,99,255,0.03); }
  .tag { display: inline-block; padding: 3px 10px; border-radius: 100px; font-size: 11px; font-weight: 600; }
  .tag.purple { background: rgba(108,99,255,0.1); color: var(--primary); border: 1px solid rgba(108,99,255,0.2); }
  .tag.green { background: rgba(18,183,106,0.1); color: #0a6641; border: 1px solid rgba(18,183,106,0.2); }
  .tag.red { background: rgba(233,64,112,0.1); color: #b8204e; border: 1px solid rgba(233,64,112,0.2); }
  .tag.blue { background: rgba(14,165,233,0.1); color: #0369a1; border: 1px solid rgba(14,165,233,0.2); }
  .tag.yellow { background: rgba(217,119,6,0.1); color: #92400e; border: 1px solid rgba(217,119,6,0.2); }

  /* ── Code block ── */
  .code-block { background: #f0f1f9; border: 1px solid rgba(108,99,255,0.18); border-radius: var(--radius-sm); padding: 24px; margin: 20px 0; overflow-x: auto; font-family: 'JetBrains Mono', monospace; font-size: 12px; line-height: 1.8; color: #2d2e52; }
  .code-block .key { color: #5c4fd6; }
  .code-block .val { color: #1a7a4a; }
  .code-block .str { color: #c0392b; }
  .code-block .comment { color: #9899b8; font-style: italic; }
  .code-block .fn { color: #3b5fc2; }
  .code-block .type { color: #b45309; }
  .code-block .num { color: #d4501b; }

  /* ── Agents ── */
  .agent-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; margin-top: 32px; }
  .agent-card { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 24px; transition: all 0.3s; box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
  .agent-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--border); }
  .agent-card-top { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
  .agent-avatar { width: 48px; height: 48px; border-radius: 14px; display: flex; align-items: center; justify-content: center; font-size: 22px; flex-shrink: 0; }
  .agent-card-name { font-size: 15px; font-weight: 700; }
  .agent-card-role { font-size: 11px; color: var(--text3); font-weight: 500; }
  .agent-card p { font-size: 12px; color: var(--text2); line-height: 1.6; margin-bottom: 14px; }
  .agent-card-tags { display: flex; flex-wrap: wrap; gap: 6px; }

  /* ── Flow ── */
  .flow { display: flex; flex-direction: column; gap: 4px; margin: 24px 0; }
  .flow-step { display: flex; align-items: flex-start; gap: 16px; padding: 16px 20px; background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius-sm); transition: all 0.2s; }
  .flow-step:hover { border-color: var(--primary); }
  .flow-num { width: 30px; height: 30px; border-radius: 50%; background: var(--primary); color: #fff; font-size: 12px; font-weight: 700; display: flex; align-items: center; justify-content: center; flex-shrink: 0; margin-top: 2px; }
  .flow-content h4 { font-size: 14px; font-weight: 700; margin-bottom: 4px; }
  .flow-content p { font-size: 12px; color: var(--text2); line-height: 1.5; }
  .flow-arrow { text-align: center; color: var(--text3); font-size: 18px; padding: 2px 0; }

  /* ── Algo ── */
  .algo-box { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 28px; box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
  .algo-box h3 { font-size: 18px; font-weight: 700; margin-bottom: 6px; }
  .algo-steps { display: flex; flex-direction: column; gap: 4px; margin-top: 20px; }
  .algo-step { display: flex; align-items: flex-start; gap: 14px; padding: 14px 18px; background: var(--bg2); border-radius: var(--radius-sm); }
  .algo-step-num { width: 28px; height: 28px; border-radius: 50%; background: var(--primary); color: #fff; font-size: 11px; font-weight: 700; display: flex; align-items: center; justify-content: center; flex-shrink: 0; margin-top: 2px; }
  .algo-step-content h4 { font-size: 13px; font-weight: 700; margin-bottom: 4px; }
  .algo-step-content p { font-size: 12px; color: var(--text2); line-height: 1.5; }

  /* ── Roles ── */
  .role-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-bottom: 32px; }
  @media (max-width: 700px) { .role-grid { grid-template-columns: 1fr; } }
  .role-col-title { font-size: 13px; font-weight: 700; margin-bottom: 16px; }
  .role-item { display: flex; gap: 12px; padding: 14px; background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius-sm); margin-bottom: 10px; }
  .role-item-icon { font-size: 20px; flex-shrink: 0; }
  .role-item-name { font-size: 13px; font-weight: 700; margin-bottom: 4px; }
  .role-item-desc { font-size: 12px; color: var(--text2); line-height: 1.5; }

  /* ── Misc ── */
  .formula { background: var(--card2); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 20px 24px; font-family: 'JetBrains Mono', monospace; font-size: 13px; line-height: 1.8; color: var(--text2); margin: 20px 0; }
  .formula .type { color: var(--primary); font-weight: 600; }
  .formula .var { color: #c0392b; }
  .formula .op { color: var(--text3); }
  .formula .comment { color: var(--text3); font-style: italic; }
  .divider { height: 1px; background: var(--border2); margin: 32px 0; }
  .privacy-section { padding: 24px; background: var(--card); border-radius: var(--radius); border: 1px solid var(--border2); margin-bottom: 32px; }
  .privacy-section h3 { font-size: 16px; font-weight: 700; margin-bottom: 20px; }
  .privacy-section .card-grid { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
  .matrix-table th, .matrix-table td { text-align: center; }
  .matrix-table td:first-child { text-align: left; font-weight: 600; }
  .dot { width: 8px; height: 8px; border-radius: 50%; display: inline-block; }
  .dot.high { background: var(--success); }
  .dot.med { background: var(--warning); }
  .dot.low { background: var(--danger); }
  .risk-row-high td { background: rgba(233,64,112,0.03); }
  .risk-row-med td { background: rgba(217,119,6,0.03); }
  .risk-row-low td { background: rgba(18,183,106,0.03); }
  .doc-footer { background: var(--bg2); border-top: 1px solid var(--border2); padding: 40px; text-align: center; font-size: 13px; color: var(--text3); line-height: 1.8; }

  /* Floating Back Navigation Bar */
  .nav-back-bar {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 10000;
    display: flex;
    gap: 12px;
    pointer-events: none;
  }
  .nav-back-link {
    pointer-events: auto;
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
    background: rgba(255, 255, 255, 0.75);
    border: 1px solid var(--border);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    padding: 8px 16px;
    border-radius: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.25s ease;
  }
  .nav-back-link:hover {
    background: #fff;
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(108, 99, 255, 0.15);
    border-color: rgba(108, 99, 255, 0.4);
    color: var(--primary);
  }
  .nav-back-link:active {
    transform: translateY(0);
  }
  
  @media print {
    .nav-back-bar { display: none !important; }
  }
  @media (max-width: 600px) {
    .nav-back-bar {
      top: 12px;
      left: 12px;
      gap: 8px;
    }
    .nav-back-link {
      padding: 6px 12px;
      font-size: 11px;
    }
  }

/* Language Selector Styles */
.lang-select-wrap {
  display: flex;
  align-items: center;
}
.lang-select {
  background: rgba(108, 99, 255, 0.05);
  border: 1px solid rgba(108,92,231,0.25);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  outline: none;
  transition: all 0.2s;
  font-family: inherit;
}
.lang-select:hover {
  border-color: rgba(108,92,231,0.4);
  background: rgba(108,92,231,0.1);
}
.lang-select option {
  background: var(--card);
  color: var(--text);
}

/* Floating Right Navigation Bar */
.nav-right-bar {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 10000;
  pointer-events: none;
}
.btn-sandbox {
  pointer-events: auto;
  background: linear-gradient(135deg, var(--primary) 0%, #a29bfe 100%);
  color: white !important;
  border: none;
  padding: 8px 18px;
  border-radius: 20px;
  cursor: pointer;
  font-weight: 700;
  font-family: inherit;
  font-size: 13px;
  box-shadow: 0 4px 12px rgba(108,99,255,0.25);
  transition: all 0.2s;
  outline: none;
  display: flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
}
.btn-sandbox:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(108,99,255,0.4);
}
.btn-sandbox:active {
  transform: translateY(0);
}

@media (max-width: 600px) {
  .nav-right-bar {
    top: 12px;
    right: 12px;
  }
  .btn-sandbox {
    padding: 6px 12px;
    font-size: 11px;
  }
}