* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        :root {
            --primary-color: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary-color: #64748b;
            --accent-color: #06b6d4;
            --success-color: #10b981;
            --warning-color: #f59e0b;
            --danger-color: #ef4444;
            --background: #ffffff;
            --surface: #f8fafc;
            --surface-hover: #f1f5f9;
            --text-primary: #1e293b;
            --text-secondary: #64748b;
            --border: #e2e8f0;
            --sidebar-width: 280px;
        }

        [data-theme="dark"] {
            --background: #0f172a;
            --surface: #1e293b;
            --surface-hover: #334155;
            --text-primary: #f8fafc;
            --text-secondary: #cbd5e1;
            --border: #334155;
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
            line-height: 1.6;
            color: var(--text-primary);
            background: var(--background);
            transition: all 0.3s ease;
        }

        .container {
            display: flex;
            min-height: 100vh;
        }

        /* Header */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            height: 60px;
            background: var(--background);
            border-bottom: 1px solid var(--border);
            z-index: 1000;
            display: flex;
            align-items: center;
            padding: 0 20px;
            gap: 20px;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 1.2rem;
            color: var(--primary-color);
            text-decoration: none;
        }

        .logo-icon {
            width: 32px;
            height: 32px;
            background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
        }

        .search-container {
            flex: 1;
            max-width: 500px;
            position: relative;
        }

        .search-input {
            width: 100%;
            padding: 10px 40px 10px 16px;
            border: 1px solid var(--border);
            border-radius: 8px;
            background: var(--surface);
            color: var(--text-primary);
            font-size: 14px;
        }

        .search-input:focus {
            outline: none;
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }

        .search-icon {
            position: absolute;
            right: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--text-secondary);
        }

        .theme-toggle {
            padding: 8px;
            border: 1px solid var(--border);
            border-radius: 6px;
            background: var(--surface);
            color: var(--text-primary);
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .theme-toggle:hover {
            background: var(--surface-hover);
        }

        /* Sidebar */
        .sidebar {
            position: fixed;
            left: 0;
            top: 60px;
            width: var(--sidebar-width);
            height: calc(100vh - 60px);
            background: var(--surface);
            border-right: 1px solid var(--border);
            overflow-y: auto;
            z-index: 100;
        }

        .sidebar-nav {
            padding: 20px 0;
        }

        .nav-section {
            margin-bottom: 24px;
        }

        .nav-section h3 {
            font-size: 12px;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: var(--text-secondary);
            padding: 0 20px 8px;
        }

        .nav-item {
            display: block;
            padding: 10px 20px;
            color: var(--text-primary);
            text-decoration: none;
            border-left: 3px solid transparent;
            transition: all 0.2s ease;
            cursor: pointer;
            position: relative;
        }

        .nav-item:hover {
            background: var(--surface-hover);
            border-left-color: var(--primary-color);
        }

        .nav-item.active {
            background: var(--primary-color);
            color: white;
            border-left-color: var(--primary-dark);
        }

        .nav-item .icon {
            width: 20px;
            height: 20px;
            margin-right: 10px;
            display: inline-block;
        }

        /* Main Content */
        .main-content {
            margin-left: var(--sidebar-width);
            margin-top: 60px;
            flex: 1;
            padding: 40px;
            width: calc(100vw - var(--sidebar-width));
            max-width: calc(100vw - var(--sidebar-width));
        }

        .content-header {
            margin-bottom: 32px;
        }

        .breadcrumb {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 14px;
            color: var(--text-secondary);
            margin-bottom: 16px;
        }

        .breadcrumb a {
            color: var(--text-secondary);
            text-decoration: none;
        }

        .breadcrumb a:hover {
            color: var(--primary-color);
        }

        h1 {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: 8px;
        }

        .subtitle {
            font-size: 1.2rem;
            color: var(--text-secondary);
            margin-bottom: 24px;
        }

        .content-section {
            display: none;
        }

        .content-section.active {
            display: block;
            animation: fadeIn 0.3s ease;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* Cards */
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 24px;
            margin-bottom: 40px;
        }

        .feature-card {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 12px;
            padding: 24px;
            transition: all 0.2s ease;
        }

        .feature-card:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }

        .feature-card h3 {
            font-size: 1.25rem;
            font-weight: 600;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .feature-card p {
            color: var(--text-secondary);
            margin-bottom: 16px;
        }

        .feature-card ul {
            list-style: none;
            margin-left: 0;
        }

        .feature-card li {
            padding: 4px 0;
            color: var(--text-secondary);
        }

        .feature-card li:before {
            content: "•";
            color: var(--primary-color);
            font-weight: bold;
            margin-right: 8px;
        }

        /* General list styles for content outside feature cards */
        .content-section ul:not(.feature-card ul) {
            list-style: none;
            margin: 16px 0;
            padding-left: 0;
        }

        .content-section ul:not(.feature-card ul) li {
            padding: 6px 0;
            color: var(--text-secondary);
            margin-left: 0;
        }

        .content-section ul:not(.feature-card ul) li:before {
            content: "•";
            color: var(--primary-color);
            font-weight: bold;
            margin-right: 10px;
        }

        .content-section ol {
            margin: 16px 0;
            padding-left: 20px;
            color: var(--text-secondary);
        }

        .content-section ol li {
            padding: 4px 0;
            margin-left: 0;
        }

        /* Badge */
        .badge {
            display: inline-block;
            padding: 4px 8px;
            border-radius: 4px;
            font-size: 12px;
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .badge-primary { background: var(--primary-color); color: white; }
        .badge-success { background: var(--success-color); color: white; }
        .badge-warning { background: var(--warning-color); color: white; }
        .badge-danger { background: var(--danger-color); color: white; }

        /* Code blocks */
        pre {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 8px;
            padding: 16px;
            margin: 16px 0;
            overflow-x: auto;
            font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
            font-size: 14px;
        }

        code {
            background: var(--surface);
            padding: 2px 6px;
            border-radius: 4px;
            font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
            font-size: 14px;
        }

        /* Tables */
        .table-container {
            overflow-x: auto;
            margin: 24px 0;
        }

        table {
            width: 100%;
            border-collapse: collapse;
            background: var(--surface);
            border-radius: 8px;
            overflow: hidden;
        }

        th, td {
            padding: 12px 16px;
            text-align: left;
            border-bottom: 1px solid var(--border);
        }

        th {
            background: var(--surface-hover);
            font-weight: 600;
            color: var(--text-primary);
        }

        /* Links */
        .content-section a {
            color: var(--primary-color);
            text-decoration: none;
            border-bottom: 1px solid transparent;
            transition: all 0.2s ease;
        }

        .content-section a:hover {
            color: var(--primary-dark);
            border-bottom-color: var(--primary-color);
        }

        .content-section a:focus {
            outline: 2px solid var(--primary-color);
            outline-offset: 2px;
        }

        /* External link indicator */
        .content-section a[href^="http"]:after {
            content: " ↗";
            font-size: 0.8em;
            color: var(--text-secondary);
            margin-left: 2px;
        }

        /* Alerts */
        .alert {
            padding: 16px;
            border-radius: 8px;
            margin: 16px 0;
            border-left: 4px solid;
        }

        .alert-info {
            background: rgba(37, 99, 235, 0.1);
            border-left-color: var(--primary-color);
            color: var(--text-primary);
        }

        .alert-success {
            background: rgba(16, 185, 129, 0.1);
            border-left-color: var(--success-color);
            color: var(--text-primary);
        }

        .alert-warning {
            background: rgba(245, 158, 11, 0.1);
            border-left-color: var(--warning-color);
            color: var(--text-primary);
        }

        /* Placeholder content styling */
        .placeholder-section {
            background: var(--surface);
            border: 2px dashed var(--border);
            border-radius: 12px;
            padding: 32px;
            margin: 24px 0;
            text-align: center;
            color: var(--text-secondary);
        }

        .placeholder-section h3 {
            color: var(--text-primary);
            margin-bottom: 16px;
            font-size: 1.3rem;
        }

        .placeholder-section .placeholder-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 16px;
            display: block;
        }

        .placeholder-section .placeholder-description {
            font-size: 1rem;
            line-height: 1.6;
            margin-bottom: 20px;
        }

        .placeholder-section .placeholder-help {
            font-size: 0.9rem;
            color: var(--text-secondary);
            font-style: italic;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .sidebar {
                transform: translateX(-100%);
                transition: transform 0.3s ease;
            }

            .sidebar.mobile-open {
                transform: translateX(0);
            }

            .main-content {
                margin-left: 0;
                padding: 20px;
            }

            /* When sidebar opens on mobile, dock (push) the main content and header smoothly
               Use transform to avoid layout reflow and sudden jumps. */
            body.sidebar-open {
                overflow-x: hidden; /* prevent horizontal scroll while docked */
            }

            body.sidebar-open .main-content {
                transform: translateX(var(--sidebar-width));
                max-width: calc(100vw - var(--sidebar-width) - 40px);
                transition: transform 0.3s ease, max-width 0.3s ease;
            }

            body.sidebar-open .header {
                transform: translateX(var(--sidebar-width));
                width: calc(100% - var(--sidebar-width));
                transition: transform 0.3s ease, width 0.3s ease;
            }

            .header {
                padding: 0 16px;
            }

            .search-container {
                display: none;
            }
        }