:root {
            --primary: #5156be;
            --primary-hover: #3b3f94;
            --text-dark: #2d3748;
            --text-body: #4a5568;
            --text-muted: #6c7293;
            --bg-light: #f8f9fa;
            --border-color: #e2e8f0;
            --card-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            color: var(--text-body);
            background: var(--bg-light);
            font-size: 16px;
            line-height: 1.6;
        }

        /* Navigation */
        .navbar {
            background: white;
            box-shadow: var(--card-shadow);
            padding: 0;
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        .nav-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 64px;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            text-decoration: none;
            color: var(--text-dark);
            font-size: 24px;
            font-weight: 600;
        }

        /* Documentation Layout */
        .doc-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 40px 20px;
        }

        .doc-sidebar {
            position: sticky;
            top: 100px;
            height: fit-content;
            background: white;
            border-radius: 8px;
            padding: 20px;
            box-shadow: var(--card-shadow);
        }

        .doc-nav {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .doc-nav li {
            margin-bottom: 10px;
        }

        .doc-nav a {
            color: var(--text-body);
            text-decoration: none;
            display: block;
            padding: 8px 15px;
            border-radius: 6px;
            transition: all 0.2s;
            font-size: 14px;
        }

        .doc-nav a:hover {
            background: var(--bg-light);
            color: var(--primary);
        }

        .doc-nav a.active {
            background: rgba(81, 86, 190, 0.1);
            color: var(--primary);
            font-weight: 500;
        }

        .doc-nav .nav-section {
            font-weight: 600;
            color: var(--text-dark);
            padding: 12px 15px 8px;
            font-size: 12px;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }

        .doc-content {
            background: white;
            border-radius: 8px;
            padding: 40px;
            box-shadow: var(--card-shadow);
        }

        .doc-content h1 {
            font-size: 36px;
            font-weight: 700;
            color: var(--text-dark);
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 2px solid var(--border-color);
        }

        .doc-content h2 {
            font-size: 28px;
            font-weight: 600;
            color: var(--text-dark);
            margin-top: 40px;
            margin-bottom: 20px;
            padding-top: 20px;
        }

        .doc-content h3 {
            font-size: 22px;
            font-weight: 600;
            color: var(--text-dark);
            margin-top: 30px;
            margin-bottom: 15px;
        }

        .doc-content h4 {
            font-size: 18px;
            font-weight: 600;
            color: var(--text-dark);
            margin-top: 25px;
            margin-bottom: 15px;
        }

        .doc-content p {
            margin-bottom: 20px;
            line-height: 1.8;
        }

        .doc-content ul, .doc-content ol {
            margin-bottom: 20px;
            padding-left: 30px;
        }

        .doc-content li {
            margin-bottom: 10px;
        }

        /* Code blocks */
        .code-block {
            background: #f4f4f4;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 20px;
            margin: 20px 0;
            font-family: 'Consolas', 'Monaco', monospace;
            font-size: 14px;
            overflow-x: auto;
            position: relative;
        }

        .code-block code {
            color: #333;
            background: none;
            padding: 0;
        }

        .copy-btn {
            position: absolute;
            top: 10px;
            right: 10px;
            background: var(--primary);
            color: white;
            border: none;
            padding: 5px 15px;
            border-radius: 4px;
            font-size: 12px;
            cursor: pointer;
            transition: all 0.2s;
        }

        .copy-btn:hover {
            background: var(--primary-hover);
        }

        /* Alert boxes */
        .alert-box {
            padding: 20px;
            border-radius: 6px;
            margin: 20px 0;
            display: flex;
            align-items: start;
            gap: 15px;
        }

        .alert-info {
            background: rgba(81, 86, 190, 0.1);
            border-left: 4px solid var(--primary);
        }

        .alert-warning {
            background: rgba(245, 158, 11, 0.1);
            border-left: 4px solid #f59e0b;
        }

        .alert-success {
            background: rgba(16, 185, 129, 0.1);
            border-left: 4px solid #10b981;
        }

        .alert-box i {
            font-size: 20px;
            flex-shrink: 0;
            margin-top: 2px;
        }

        /* Feature cards */
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            margin: 30px 0;
        }

        .feature-item {
            background: var(--bg-light);
            padding: 25px;
            border-radius: 8px;
            border: 1px solid var(--border-color);
        }

        .feature-item h4 {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 15px;
            color: var(--text-dark);
        }

        .feature-item i {
            color: var(--primary);
        }

        /* Steps */
        .steps {
            margin: 30px 0;
        }

        .step {
            display: flex;
            gap: 20px;
            margin-bottom: 30px;
        }

        .step-number {
            width: 40px;
            height: 40px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 600;
            flex-shrink: 0;
        }

        .step-content h4 {
            margin-top: 0;
        }

        /* Tables */
        .doc-table {
            width: 100%;
            margin: 20px 0;
            border-collapse: collapse;
            overflow-x: auto;
            display: block;
        }

        .doc-table table {
            width: 100%;
            min-width: 600px;
        }

        .doc-table th {
            background: var(--bg-light);
            padding: 12px 20px;
            text-align: left;
            font-weight: 600;
            border: 1px solid var(--border-color);
        }

        .doc-table td {
            padding: 12px 20px;
            border: 1px solid var(--border-color);
        }

        .doc-table code {
            background: rgba(81, 86, 190, 0.1);
            padding: 2px 6px;
            border-radius: 3px;
            font-size: 13px;
            color: var(--primary);
        }

        /* Image containers */
        .img-container {
            margin: 30px 0;
            text-align: center;
        }

        .img-container img {
            max-width: 100%;
            border-radius: 8px;
            box-shadow: var(--card-shadow);
        }

        .img-caption {
            margin-top: 10px;
            font-size: 14px;
            color: var(--text-muted);
            font-style: italic;
        }

        /* Responsive */
        @media (max-width: 992px) {
            .doc-sidebar {
                position: relative;
                margin-bottom: 30px;
            }
            
            .doc-content {
                padding: 30px 20px;
            }
        }

        /* Smooth scroll */
        html {
            scroll-behavior: smooth;
        }

        /* Parameter Flow Diagrams */
        .param-flow {
            margin: 40px 0;
            background: var(--bg-light);
            border-radius: 12px;
            padding: 40px;
        }

        .flow-diagram {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 20px;
        }

        .flow-step {
            background: white;
            border: 2px solid var(--border-color);
            border-radius: 10px;
            padding: 25px;
            width: 100%;
            max-width: 500px;
            text-align: center;
            transition: all 0.3s;
        }

        .flow-step:hover {
            border-color: var(--primary);
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(81, 86, 190, 0.1);
        }

        .flow-icon {
            width: 50px;
            height: 50px;
            background: rgba(81, 86, 190, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 15px;
        }

        .flow-icon i {
            font-size: 24px;
            color: var(--primary);
        }

        .flow-step h5 {
            margin-bottom: 10px;
            color: var(--text-dark);
        }

        .flow-step code {
            background: var(--bg-light);
            padding: 10px;
            border-radius: 6px;
            display: block;
            font-size: 13px;
            word-break: break-all;
        }

        .flow-arrow {
            font-size: 30px;
            color: var(--primary);
            animation: bounce 2s infinite;
        }

        @keyframes bounce {
            0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
            40% { transform: translateY(-10px); }
            60% { transform: translateY(-5px); }
        }

        /* Email Example */
        .email-example {
            background: white;
            border: 2px solid var(--primary);
            border-radius: 12px;
            padding: 30px;
            margin: 30px 0;
        }

        .email-example h4 {
            color: var(--primary);
            margin-bottom: 25px;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .example-flow {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 20px;
        }

        .example-box {
            flex: 1;
            min-width: 200px;
            text-align: center;
        }

        .example-box h5 {
            color: var(--text-dark);
            margin-bottom: 15px;
        }

        .form-visual {
            background: var(--bg-light);
            border-radius: 8px;
            padding: 20px;
            display: inline-block;
        }

        .form-input {
            background: white;
            border: 1px solid var(--border-color);
            padding: 10px 15px;
            border-radius: 4px;
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 10px;
        }

        .form-btn {
            background: var(--primary);
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 4px;
            cursor: pointer;
        }

        .arrow-right {
            font-size: 24px;
            color: var(--primary);
            font-weight: bold;
        }

        .highlight {
            background: rgba(81, 86, 190, 0.2);
            padding: 2px 4px;
            border-radius: 3px;
            color: var(--primary);
            font-weight: 600;
        }

        .success-msg {
            color: #10b981;
            font-weight: 600;
            margin-top: 10px;
        }

        /* Use Cases Grid */
        .use-cases-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 25px;
            margin: 30px 0;
        }

        .use-case-card {
            background: white;
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 25px;
            text-align: center;
            transition: all 0.3s;
        }

        .use-case-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
            border-color: var(--primary);
        }

        .use-case-icon {
            width: 60px;
            height: 60px;
            background: rgba(81, 86, 190, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
        }

        .use-case-icon i {
            font-size: 28px;
            color: var(--primary);
        }

        .use-case-card h4 {
            color: var(--text-dark);
            margin-bottom: 15px;
        }

        .param-example {
            background: var(--bg-light);
            padding: 15px;
            border-radius: 6px;
            margin: 15px 0;
            text-align: left;
        }

        .param-example code {
            font-size: 12px;
            color: var(--text-dark);
        }

        /* Strategy Flow */
        .strategy-section {
            background: var(--bg-light);
            border-radius: 12px;
            padding: 30px;
            margin: 30px 0;
        }

        .strategy-flow {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-top: 25px;
            flex-wrap: wrap;
            gap: 20px;
        }

        .strategy-step {
            flex: 1;
            min-width: 200px;
            display: flex;
            align-items: flex-start;
            gap: 15px;
        }

        .step-num {
            width: 35px;
            height: 35px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 600;
            flex-shrink: 0;
        }

        .step-content h5 {
            margin-bottom: 8px;
            color: var(--text-dark);
        }

        .step-content p {
            font-size: 14px;
            margin: 0;
        }

        .strategy-arrow {
            font-size: 24px;
            color: var(--primary);
            flex-shrink: 0;
        }

        /* TOC mobile toggle */
        .toc-toggle {
            display: none;
            background: var(--primary);
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 6px;
            margin-bottom: 20px;
            width: 100%;
            font-weight: 500;
        }

        @media (max-width: 767px) {
            .toc-toggle {
                display: block;
            }
            
            .doc-sidebar {
                display: none;
            }
            
            .doc-sidebar.show {
                display: block;
            }
        }