/* extracted from inline <style> block 1 in docs/how-it-works.html */
* { margin: 0; padding: 0; box-sizing: border-box; }
    :root {
      --bg-primary: #0f172a;
      --bg-secondary: #1e293b;
      --bg-code: #0d1117;
      --accent: #10b981;
      --text-primary: #f8fafc;
      --text-secondary: #94a3b8;
      --border: rgba(255,255,255,0.1);
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: var(--bg-primary);
      color: var(--text-primary);
      line-height: 1.7;
      min-height: 100vh;
    }
    .layout {
      display: grid;
      grid-template-columns: 280px 1fr;
      min-height: 100vh;
    }
    .sidebar {
      background: var(--bg-secondary);
      border-right: 1px solid var(--border);
      padding: 24px;
      position: sticky;
      top: 0;
      height: 100vh;
      overflow-y: auto;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 800;
      color: var(--accent);
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 8px;
      margin-bottom: 32px;
    }
    .nav-section { margin-bottom: 24px; }
    .nav-section h4 {
      font-size: 0.75rem;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      color: var(--text-secondary);
      margin-bottom: 12px;
    }
    .nav-section ul { list-style: none; }
    .nav-section li { margin-bottom: 8px; }
    .nav-section a {
      color: var(--text-secondary);
      text-decoration: none;
      font-size: 0.95rem;
      transition: color 0.2s;
    }
    .nav-section a:hover, .nav-section li.active a {
      color: var(--accent);
    }
    .content {
      padding: 48px 64px;
      max-width: 900px;
    }
    .content h1 {
      font-size: 2.5rem;
      font-weight: 800;
      margin-bottom: 24px;
      color: var(--text-primary);
    }
    .content h2 {
      font-size: 1.5rem;
      font-weight: 700;
      margin: 40px 0 16px;
      color: var(--text-primary);
    }
    .content h3 {
      font-size: 1.2rem;
      font-weight: 600;
      margin: 32px 0 12px;
      color: var(--text-primary);
    }
    .content p {
      color: var(--text-secondary);
      margin-bottom: 16px;
    }
    .content ul, .content ol {
      color: var(--text-secondary);
      margin: 16px 0;
      padding-left: 24px;
    }
    .content li { margin-bottom: 8px; }
    .content code {
      background: var(--bg-code);
      padding: 2px 6px;
      border-radius: 4px;
      font-family: 'SF Mono', Monaco, monospace;
      font-size: 0.9em;
    }
    .content pre {
      background: var(--bg-code);
      border: 1px solid var(--border);
      border-radius: 8px;
      padding: 20px;
      overflow-x: auto;
      margin: 20px 0;
    }
    .content pre code {
      background: none;
      padding: 0;
      font-size: 0.85rem;
      line-height: 1.6;
    }
    .content strong { color: var(--text-primary); }
    .content a { color: var(--accent); }
    .back-link {
      display: inline-block;
      margin-bottom: 24px;
      color: var(--text-secondary);
      text-decoration: none;
      font-size: 0.9rem;
    }
    .back-link:hover { color: var(--accent); }

    /* Layer Cards */
    .layer-card {
      background: var(--bg-secondary);
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 24px;
      margin: 24px 0;
    }
    .layer-card h3 {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 0;
    }
    .layer-number {
      width: 36px;
      height: 36px;
      background: rgba(16, 185, 129, 0.15);
      border: 2px solid var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1rem;
      font-weight: 800;
      color: var(--accent);
      flex-shrink: 0;
    }
    .layer-tag {
      display: inline-block;
      padding: 4px 10px;
      background: rgba(16, 185, 129, 0.1);
      border-radius: 100px;
      font-size: 0.75rem;
      font-weight: 600;
      color: var(--accent);
      margin-top: 12px;
    }
    .highlight-box {
      background: rgba(16, 185, 129, 0.05);
      border: 1px solid rgba(16, 185, 129, 0.2);
      border-radius: 12px;
      padding: 24px;
      margin: 32px 0;
      text-align: center;
    }
    .highlight-box p {
      font-size: 1.25rem;
      font-weight: 600;
      color: var(--text-primary);
      font-style: italic;
      margin: 0;
    }
    .highlight-box p span {
      color: var(--accent);
    }
    .flow-diagram {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      margin: 32px 0;
      flex-wrap: wrap;
    }
    .flow-step {
      background: var(--bg-secondary);
      border: 1px solid var(--border);
      border-radius: 8px;
      padding: 12px 20px;
      font-size: 0.9rem;
      color: var(--text-secondary);
    }
    .flow-step.highlight {
      border-color: var(--accent);
      color: var(--accent);
    }
    .flow-arrow {
      color: var(--accent);
      font-size: 1.2rem;
    }

    @media (max-width: 900px) {
      .layout { grid-template-columns: 1fr; }
      .sidebar { display: none !important; }
      .content { padding: 24px; }
    }