/* CSS variables matching premium light-theme */
    :root {
        --bg: #f8fafc;
        --sidebar-bg: #ffffff;
        --surface: #ffffff;
        --border: #e2e8f0;
        --border-bright: #cbd5e1;
        --text: #0f172a;
        --text-dim: #64748b;
        --accent: #4f46e5; /* Indigo */
        --accent-dim: rgba(79, 70, 229, 0.08);
        --green: #059669; /* Emerald */
        --green-dim: rgba(5, 150, 105, 0.08);
        --amber: #d97706; /* Amber */
        --amber-dim: rgba(217, 119, 6, 0.08);
        --red: #dc2626; /* Red */
        --red-dim: rgba(220, 38, 38, 0.08);
        --font-sans: 'Plus Jakarta Sans', system-ui, sans-serif;
        --font-mono: 'JetBrains Mono', monospace;
    }

    * { box-sizing: border-box; margin: 0; padding: 0; }
    
    body {
        font-family: var(--font-sans);
        background: radial-gradient(ellipse at bottom right, #f1f5f9, var(--bg));
        color: var(--text);
        min-height: 100vh;
        display: grid;
        grid-template-columns: 280px 1fr;
        line-height: 1.6;
    }

    /* SIDEBAR STYLE */
    aside.app-sidebar {
        background: var(--sidebar-bg);
        border-right: 1px solid var(--border);
        padding: 1.5rem 1rem;
        display: flex;
        flex-direction: column;
        height: 100vh;
        position: sticky;
        top: 0;
        overflow-y: auto;
    }

    .sidebar-header {
        display: flex;
        align-items: center;
        gap: 0.75rem;
        padding-bottom: 1.25rem;
        border-bottom: 1px solid var(--border);
        margin-bottom: 1rem;
    }

    .logo-icon { font-size: 1.8rem; }

    .logo-text h1 {
        font-size: 1.05rem;
        font-weight: 800;
        background: linear-gradient(135deg, #4f46e5, #818cf8);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
    }

    .logo-text p {
        font-size: 0.62rem;
        color: var(--text-dim);
        letter-spacing: 0.5px;
        text-transform: uppercase;
    }

    .sidebar-nav {
        display: flex;
        flex-direction: column;
        gap: 0.35rem;
        flex-grow: 1;
    }

    .menu-title {
        font-size: 0.68rem;
        font-weight: 700;
        color: var(--text-dim);
        letter-spacing: 1px;
        margin: 0.75rem 0 0.35rem 0.25rem;
        text-transform: uppercase;
    }

    .nav-item {
        display: flex;
        align-items: center;
        gap: 0.65rem;
        padding: 0.65rem 0.75rem;
        border-radius: 0.5rem;
        color: var(--text-dim);
        text-decoration: none;
        font-size: 0.8rem;
        font-weight: 600;
        border: 1px solid transparent;
        transition: all 0.2s ease;
        cursor: pointer;
    }

    .nav-item:hover, .nav-item.active {
        background: rgba(0, 0, 0, 0.02);
        color: var(--text);
        border-color: var(--border);
    }

    .nav-item.active {
        background: var(--accent-dim);
        color: #4f46e5;
        border-color: rgba(79, 70, 229, 0.2);
    }

    /* MAIN APP CONTENT */
    main.app-main {
        display: flex;
        flex-direction: column;
        height: 100vh;
        overflow-y: auto;
    }

    .top-bar {
        background: rgba(248, 250, 252, 0.85);
        border-bottom: 1px solid var(--border);
        padding: 0.85rem 2rem;
        display: flex;
        justify-content: space-between;
        align-items: center;
        position: sticky;
        top: 0;
        backdrop-filter: blur(10px);
        z-index: 10;
    }

    .breadcrumb {
        font-weight: 700;
        font-size: 0.92rem;
        background: linear-gradient(135deg, #0f172a, #475569);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
    }

    .quick-links {
        display: flex;
        gap: 0.5rem;
    }

    .btn-link {
        font-size: 0.75rem;
        color: var(--text-dim);
        text-decoration: none;
        padding: 0.4rem 0.75rem;
        border: 1px solid var(--border);
        border-radius: 0.35rem;
        background: rgba(0, 0, 0, 0.02);
        transition: all 0.25s;
        font-weight: 600;
        display: inline-flex;
        align-items: center;
        gap: 4px;
    }

    .btn-link:hover {
        color: var(--text);
        border-color: var(--border-bright);
        background: rgba(0, 0, 0, 0.05);
    }

    .btn-link.highlight {
        color: var(--accent);
        border-color: rgba(79, 70, 229, 0.3);
        background: var(--accent-dim);
    }

    .btn-link.highlight:hover {
        background: rgba(79, 70, 229, 0.2);
        border-color: rgba(79, 70, 229, 0.5);
    }

    .content-area {
        padding: 2rem;
        max-width: 1000px;
        width: 100%;
        margin: 0 auto;
    }

    /* Glass Cards */
    .glass-card {
        background: var(--surface);
        border: 1px solid var(--border);
        border-radius: 0.75rem;
        padding: 1.5rem;
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.03);
        margin-bottom: 1.5rem;
        transition: border-color 0.25s ease;
    }

    .glass-card:hover {
        border-color: var(--border-bright);
    }

    .glass-card h2 {
        font-size: 1.2rem;
        font-weight: 700;
        margin-bottom: 1rem;
        display: flex;
        align-items: center;
        gap: 0.5rem;
        color: var(--text);
    }

    .intro-title h1 {
        font-size: 1.8rem;
        font-weight: 800;
        background: linear-gradient(135deg, #0f172a, #4f46e5, #818cf8);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        margin-bottom: 0.5rem;
    }

    .intro-title p {
        color: var(--text-dim);
        font-size: 0.9rem;
        margin-bottom: 1.5rem;
    }

    /* Data Tables */
    .table-wrap {
        border: 1px solid var(--border);
        border-radius: 0.5rem;
        overflow: hidden;
        background: #ffffff;
        margin-top: 0.5rem;
        margin-bottom: 1rem;
    }

    .data-table {
        width: 100%;
        border-collapse: collapse;
        font-size: 0.8rem;
        text-align: left;
    }

    .data-table th {
        background: rgba(0, 0, 0, 0.01);
        color: var(--text-dim);
        padding: 0.75rem 1rem;
        font-weight: 600;
        border-bottom: 1px solid var(--border);
    }

    .data-table td {
        padding: 0.75rem 1rem;
        border-bottom: 1px solid var(--border);
        color: var(--text);
        vertical-align: top;
    }

    .data-table tbody tr:hover {
        background: rgba(0, 0, 0, 0.005);
    }

    .data-table tr:last-child td {
        border-bottom: none;
    }

    .in-scope { color: var(--green); font-weight: bold; }
    .out-scope { color: var(--red); font-weight: bold; }

    /* Flow list & badges */
    .status-badge {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        padding: 0.2rem 0.5rem;
        border-radius: 9999px;
        font-size: 0.68rem;
        font-weight: 700;
        text-transform: uppercase;
        letter-spacing: 0.5px;
        border: 1px solid transparent;
    }

    .badge-indigo {
        background: var(--accent-dim);
        color: #4f46e5;
        border-color: rgba(79, 70, 229, 0.2);
    }

    .badge-green {
        background: var(--green-dim);
        color: #059669;
        border-color: rgba(5, 150, 105, 0.2);
    }

    .badge-amber {
        background: var(--amber-dim);
        color: #d97706;
        border-color: rgba(217, 119, 6, 0.2);
    }

    .badge-red {
        background: var(--red-dim);
        color: #dc2626;
        border-color: rgba(220, 38, 38, 0.2);
    }

    .happy-path-box {
        background: rgba(0, 0, 0, 0.005);
        border-left: 3px solid var(--accent);
        padding: 1rem;
        border-radius: 0 0.5rem 0.5rem 0;
        margin-bottom: 1rem;
        margin-top: 1rem;
    }

    .happy-path-box h4 {
        font-size: 0.88rem;
        font-weight: 700;
        margin-bottom: 0.5rem;
        color: var(--text);
    }

    .happy-path-flow {
        display: flex;
        align-items: center;
        gap: 8px;
        overflow-x: auto;
        padding: 0.5rem 0;
        font-size: 0.76rem;
    }

    .flow-node {
        background: #ffffff;
        border: 1px solid var(--border);
        padding: 0.5rem 0.75rem;
        border-radius: 0.35rem;
        white-space: nowrap;
        font-weight: 600;
        box-shadow: 0 2px 4px rgba(0,0,0,0.01);
    }

    .flow-arrow {
        color: var(--text-dim);
        font-weight: bold;
    }

    /* Modules spec grid */
    .module-group {
        border-bottom: 1px solid var(--border);
        padding: 1.25rem 0;
    }

    .module-group:last-child {
        border-bottom: none;
    }

    .module-header {
        font-size: 1rem;
        font-weight: 700;
        color: var(--accent);
        margin-bottom: 0.5rem;
        display: flex;
        align-items: center;
        gap: 6px;
    }

    .module-desc {
        font-size: 0.8rem;
        color: var(--text-dim);
        margin-bottom: 0.75rem;
    }

    .module-grid {
        display: flex;
        flex-direction: column;
        gap: 0.75rem;
        margin-top: 0.75rem;
        background: rgba(255, 255, 255, 0.4);
        border: 1px solid var(--border);
        border-radius: 0.75rem;
        padding: 1.25rem;
    }

    .grid-row {
        display: grid;
        grid-template-columns: 140px 1fr;
        gap: 1.25rem;
        align-items: start;
        font-size: 0.8rem;
    }

    .grid-label {
        font-weight: 700;
        color: var(--accent);
        text-transform: uppercase;
        font-size: 0.65rem;
        letter-spacing: 0.5px;
        background: var(--accent-dim);
        padding: 0.25rem 0.5rem;
        border-radius: 4px;
        text-align: center;
        border: 1px solid rgba(79, 70, 229, 0.08);
    }

    .grid-value {
        color: var(--text);
        padding-top: 0.1rem;
    }

    .code-block {
        font-family: var(--font-mono);
        font-size: 0.72rem;
        background: #0f172a;
        border: 1px solid var(--border);
        border-radius: 0.5rem;
        padding: 1rem;
        overflow-x: auto;
        margin: 1rem 0;
        color: #e2e8f0;
    }

    /* Pitch guide tabs */
    .tab-bar {
      display: flex;
      border-bottom: 1px solid var(--border);
      margin-bottom: 1rem;
      gap: 4px;
    }

    .tab-btn {
      padding: 8px 16px;
      border: 1px solid var(--border);
      border-bottom: none;
      border-radius: 6px 6px 0 0;
      background: rgba(0, 0, 0, 0.02);
      cursor: pointer;
      font-size: 0.75rem;
      font-weight: 700;
      transition: all 0.2s;
      color: var(--text-dim);
    }

    .tab-btn.active {
      background: #fff;
      color: var(--accent);
      border-color: var(--border);
      border-bottom: 2px solid #fff;
      position: relative;
      top: 1px;
      z-index: 2;
    }

    .tab-content {
      display: none;
      padding: 1.25rem;
      background: #fff;
      border: 1px solid var(--border);
      border-radius: 0 0 6px 6px;
      box-shadow: 0 4px 12px rgba(0,0,0,0.01);
      animation: fadeIn 0.3s ease;
    }

    .tab-content.active {
      display: block;
    }

    section {
        scroll-margin-top: 80px;
    }

    @media (max-width: 768px) {
        body { grid-template-columns: 1fr; }
        aside.app-sidebar { display: none; }
    }