/* Reset and Base Styles */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Vazirmatn', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        :root {
            --primary: #1a5276;
            --secondary: #2980b9;
            --accent: #e74c3c;
            --light: #ecf0f1;
            --dark: #2c3e50;
            --success: #27ae60;
            --warning: #f39c12;
            --info: #17a2b8;
            --transition: all 0.3s ease;
            --shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            --radius: 10px;
        }
        
        [data-theme="dark"] {
            --primary: #3498db;
            --secondary: #2c8ac9;
            --accent: #e74c3c;
            --light: #2c3e50;
            --dark: #ecf0f1;
            --success: #2ecc71;
            --warning: #f1c40f;
            --info: #1abc9c;
        }
        
        body {
            background-color: #f8f9fa;
            color: #333;
            line-height: 1.8;
            font-size: 16px;
            counter-reset: section;
            transition: var(--transition);
        }
        
        body.dark-mode {
            background-color: #1a1a2e;
            color: #e6e6e6;
        }
        
        /* New Modern Header Styles */
        :root {
            --primary-color: #2c3e50;
            --secondary-color: #3498db;
            --accent-color: #e74c3c;
            --light-color: #ecf0f1;
            --dark-color: #2c3e50;
            --text-color: #333;
            --text-light: #7f8c8d;
            --white: #ffffff;
            --shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }
        
        /* Dark Theme Variables */
        [data-theme="dark"] {
            --primary-color: #1a1a2e;
            --secondary-color: #0f3460;
            --accent-color: #e94560;
            --light-color: #16213e;
            --dark-color: #0f3460;
            --text-color: #f1f1f1;
            --text-light: #bdc3c7;
        }
        
        /* Header Styles */
        .site-header {
            background-color: var(--white);
            box-shadow: var(--shadow);
            position: fixed;
            width: 100%;
            top: 0;
            left: 0;
            z-index: 1000;
            transition: var(--transition);
            font-family: 'Vazirmatn', sans-serif;
        }
        
        .header-container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 70px;
        }
        
        /* Brand Section */
        .brand-section {
            display: flex;
            align-items: center;
        }
        
        .logo {
            display: flex;
            align-items: center;
            text-decoration: none;
            color: var(--text-color);
            font-weight: 700;
            font-size: 1.3rem;
            transition: var(--transition);
        }
        
        .logo:hover {
            color: var(--secondary-color);
        }
        
        .logo-icon {
            color: var(--accent-color);
            margin-left: 10px;
            font-size: 1.6rem;
        }
        
        /* Navigation */
        .main-nav {
            flex: 1;
            display: flex;
            justify-content: center;
        }
        
        .nav-list {
            display: flex;
            list-style: none;
            margin: 0;
            padding: 0;
        }
        
        .nav-item {
            margin: 0 5px;
        }
        
        .nav-link {
            display: flex;
            align-items: center;
            padding: 10px 18px;
            color: var(--text-color);
            text-decoration: none;
            border-radius: 6px;
            transition: var(--transition);
            font-weight: 500;
            font-size: 0.95rem;
        }
        
        .nav-link i {
            margin-left: 8px;
            font-size: 1.1em;
            color: var(--accent-color);
        }
        
        .nav-link:hover {
            background-color: rgba(52, 152, 219, 0.1);
            color: var(--secondary-color);
        }
        
        .nav-link.active {
            background-color: var(--secondary-color);
            color: white !important;
        }
        
        .nav-link.active i {
            color: white;
        }
        
        /* Header Actions */
        .header-actions {
            display: flex;
            align-items: center;
            gap: 15px;
        }
        
        /* Search Box */
        .search-box {
            position: relative;
            display: flex;
            align-items: center;
        }
        
        .search-input {
            padding: 8px 15px;
            border: 1px solid #ddd;
            border-radius: 20px;
            width: 200px;
            font-family: 'Vazirmatn', sans-serif;
            transition: var(--transition);
            padding-left: 40px;
        }
        
        .search-input:focus {
            outline: none;
            border-color: var(--secondary-color);
            box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
        }
        
        .search-btn {
            position: absolute;
            left: 10px;
            background: none;
            border: none;
            color: var(--text-light);
            cursor: pointer;
            transition: var(--transition);
        }
        
        .search-btn:hover {
            color: var(--secondary-color);
        }
        
        /* Theme Toggle */
        .theme-toggle {
            display: flex;
            align-items: center;
            gap: 8px;
            background: var(--light-color);
            padding: 6px 12px;
            border-radius: 20px;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .theme-toggle:hover {
            background: #e0e0e0;
        }
        
        .theme-toggle i {
            color: var(--text-color);
            font-size: 1.1rem;
        }
        
        .theme-toggle .fa-sun {
            color: #f1c40f;
        }
        
        .switch {
            position: relative;
            display: inline-block;
            width: 50px;
            height: 24px;
        }
        
        .switch input {
            opacity: 0;
            width: 0;
            height: 0;
        }
        
        .slider {
            position: absolute;
            cursor: pointer;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-color: #ccc;
            transition: .4s;
            border-radius: 34px;
        }
        
        .slider:before {
            position: absolute;
            content: "";
            height: 16px;
            width: 16px;
            left: 4px;
            bottom: 4px;
            background-color: white;
            transition: .4s;
            border-radius: 50%;
        }
        
        input:checked + .slider {
            background-color: #2196F3;
        }
        
        input:focus + .slider {
            box-shadow: 0 0 1px #2196F3;
        }
        
        input:checked + .slider:before {
            transform: translateX(26px);
        }
        
        /* Mobile Menu Toggle */
        .mobile-menu-toggle {
            display: none;
            flex-direction: column;
            justify-content: space-between;
            width: 30px;
            height: 21px;
            background: none;
            border: none;
            cursor: pointer;
            padding: 0;
            margin-right: 15px;
        }
        
        .menu-bar {
            width: 100%;
            height: 3px;
            background-color: var(--text-color);
            border-radius: 2px;
            transition: var(--transition);
        }
        
        /* Responsive Styles */
        @media (max-width: 992px) {
            .header-container {
                padding: 0 15px;
            }
            
            .main-nav {
                position: fixed;
                top: 70px;
                right: -100%;
                width: 80%;
                max-width: 400px;
                height: calc(100vh - 70px);
                background-color: var(--white);
                box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
                transition: var(--transition);
                padding: 20px;
                overflow-y: auto;
                z-index: 999;
            }
            
            .main-nav.active {
                right: 0;
            }
            
            .nav-list {
                flex-direction: column;
                width: 100%;
            }
            
            .nav-item {
                margin: 5px 0;
                width: 100%;
            }
            
            .nav-link {
                padding: 12px 15px;
                border-radius: 8px;
            }
            
            .mobile-menu-toggle {
                display: flex;
            }
            
            .header-actions {
                margin-right: auto;
                margin-left: 15px;
            }
            
            .search-box {
                display: none;
            }
        }
        
        @media (max-width: 576px) {
            .logo-text {
                display: none;
            }
            
            .theme-toggle span {
                display: none;
            }
        }
        
        .container {
            width: 90%;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            display: flex;
            align-items: center;
        }
        
        .logo h1 {
            font-size: 1.6rem;
            margin-right: 10px;
        }
        
        .logo-icon {
            font-size: 2rem;
            color: var(--accent);
        }
        
        nav ul {
            display: flex;
            list-style: none;
        }
        
        nav ul li {
            margin: 0 8px;
        }
        
        nav ul li a {
            color: white;
            text-decoration: none;
            padding: 8px 15px;
            border-radius: 5px;
            transition: var(--transition);
            font-weight: 500;
            font-size: 0.95rem;
        }
        
        nav ul li a:hover {
            background-color: rgba(255, 255, 255, 0.2);
        }
        
        .theme-toggle {
            background: none;
            border: none;
            color: white;
            font-size: 1.2rem;
            cursor: pointer;
            margin-right: 15px;
        }
        
        .mobile-menu {
            display: none;
            font-size: 1.5rem;
            cursor: pointer;
        }
        
        /* Hero Section */
        .hero {
            background: linear-gradient(135deg, var(--secondary), var(--primary));
            color: white;
            padding: 100px 0;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        
        .hero::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path d="M0,0 L100,0 L100,100 Z" fill="rgba(255,255,255,0.1)"/></svg>');
            background-size: cover;
        }
        
        .hero h2 {
            font-size: 2.8rem;
            margin-bottom: 20px;
            position: relative;
        }
        
        .hero p {
            font-size: 1.2rem;
            max-width: 800px;
            margin: 0 auto 30px;
            position: relative;
        }
        
        .btn {
            display: inline-block;
            background-color: var(--accent);
            color: white;
            padding: 12px 30px;
            border-radius: 5px;
            text-decoration: none;
            font-weight: bold;
            transition: var(--transition);
            border: none;
            cursor: pointer;
            font-size: 1rem;
            position: relative;
        }
        
        .btn:hover {
            background-color: #c0392b;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        }
        
        /* Main Content */
        .main-content {
            padding: 80px 0;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 50px;
            position: relative;
        }
        
        .section-title h2 {
            font-size: 2.3rem;
            color: var(--primary);
            display: inline-block;
            padding-bottom: 15px;
        }
        
        .section-title h2:after {
            content: '';
            position: absolute;
            width: 100px;
            height: 4px;
            background-color: var(--accent);
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
        }
        
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
            margin-bottom: 50px;
        }
        
        .card {
            background-color: white;
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            height: 100%;
            display: flex;
            flex-direction: column;
        }
        
        .dark-mode .card {
            background-color: #2c3e50;
            color: #e6e6e6;
        }
        
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        
        .card-img {
            height: 180px;
            background: linear-gradient(135deg, var(--secondary), var(--primary));
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 3rem;
        }
        
        .card-content {
            padding: 25px;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }
        
        .card h3 {
            color: var(--primary);
            margin-bottom: 15px;
            font-size: 1.5rem;
            border-bottom: 2px solid var(--light);
            padding-bottom: 10px;
        }
        
        .card p {
            margin-bottom: 15px;
            flex-grow: 1;
        }
        
        .card-meta {
            margin-top: auto;
            padding-top: 15px;
            border-top: 1px solid #eee;
            font-size: 0.9rem;
            color: #666;
        }
        
        /* Page Content Styles */
        .page-content {
            padding: 50px 0;
        }
        
        .page-content h2 {
            color: var(--primary);
            margin: 40px 0 20px;
            padding-bottom: 10px;
            border-bottom: 2px solid var(--light);
            font-size: 1.8rem;
            counter-increment: section;
            position: relative;
            padding-right: 40px;
        }
        
        .page-content h2:before {
            content: counter(section) ".";
            position: absolute;
            right: 0;
            color: var(--accent);
            font-weight: bold;
        }
        
        .page-content h3 {
            color: var(--secondary);
            margin: 30px 0 15px;
            font-size: 1.5rem;
            position: relative;
            padding-right: 30px;
        }
        
        .page-content h3:before {
            content: "•";
            position: absolute;
            right: 0;
            color: var(--accent);
            font-weight: bold;
        }
        
        .page-content h4 {
            color: var(--dark);
            margin: 25px 0 12px;
            font-size: 1.3rem;
        }
        
        .page-content p {
            margin-bottom: 20px;
            text-align: justify;
            line-height: 1.8;
        }
        
        .page-content ul, .page-content ol {
            margin: 20px 0;
            padding-right: 25px;
        }
        
        .page-content li {
            margin-bottom: 12px;
            position: relative;
        }
        
        .page-content ul li:before {
            content: "▪";
            color: var(--accent);
            font-weight: bold;
            display: inline-block;
            width: 1em;
            margin-right: 5px;
        }
        
        .highlight-box {
            background-color: var(--light);
            padding: 25px;
            border-radius: var(--radius);
            border-right: 5px solid var(--secondary);
            margin: 25px 0;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
        }
        
        .info-box {
            background-color: #e8f4fc;
            border: 1px solid var(--secondary);
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
        }
        
        .dark-mode .info-box {
            background-color: #1a3a4e;
        }
        
        .warning-box {
            background-color: #fef9e7;
            border: 1px solid var(--warning);
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
        }
        
        .dark-mode .warning-box {
            background-color: #4a3c1a;
        }
        
        table {
            width: 100%;
            border-collapse: collapse;
            margin: 25px 0;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            border-radius: 8px;
            overflow: hidden;
        }
        
        table th, table td {
            padding: 15px;
            text-align: right;
            border-bottom: 1px solid #ddd;
        }
        
        table th {
            background-color: var(--primary);
            color: white;
            font-weight: 600;
        }
        
        table tr:nth-child(even) {
            background-color: #f8f9fa;
        }
        
        .dark-mode table tr:nth-child(even) {
            background-color: #2c3e50;
        }
        
        table tr:hover {
            background-color: #e9f7fe;
        }
        
        .dark-mode table tr:hover {
            background-color: #34495e;
        }
        
        /* Team Section */
        .team {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 40px;
            margin-top: 50px;
        }
        
        .team-member {
            text-align: center;
            max-width: 280px;
            background: white;
            padding: 25px;
            border-radius: var(--radius);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            transition: var(--transition);
        }
        
        .dark-mode .team-member {
            background: #2c3e50;
        }
        
        .team-member:hover {
            transform: translateY(-10px);
        }
        
        .team-member .avatar {
            width: 150px;
            height: 150px;
            border-radius: 50%;
            margin-bottom: 15px;
            background: linear-gradient(135deg, var(--secondary), var(--primary));
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 3rem;
            margin: 0 auto 15px;
        }
        
        .team-member h3 {
            color: var(--primary);
            margin-bottom: 5px;
            font-size: 1.4rem;
        }
        
        .team-member p {
            color: var(--secondary);
            margin-bottom: 15px;
        }
        
        /* Footer */
        footer {
            background-color: var(--dark);
            color: white;
            padding: 60px 0 20px;
        }
        
        .footer-content {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 40px;
            margin-bottom: 40px;
        }
        
        .footer-section {
            flex: 1;
            min-width: 250px;
        }
        
        .footer-section h3 {
            font-size: 1.5rem;
            margin-bottom: 20px;
            position: relative;
            padding-bottom: 10px;
        }
        
        .footer-section h3:after {
            content: '';
            position: absolute;
            width: 50px;
            height: 2px;
            background-color: var(--accent);
            bottom: 0;
            right: 0;
        }
        
        .footer-section p {
            margin-bottom: 15px;
            line-height: 1.7;
        }
        
        .footer-bottom {
            text-align: center;
            padding-top: 20px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            font-size: 0.9rem;
            color: #ccc;
        }
        
        /* New Features */
        
        /* Progress Bar */
        .progress-container {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 5px;
            background: transparent;
            z-index: 1001;
        }
        
        .progress-bar {
            height: 5px;
            background: var(--accent);
            width: 0%;
            transition: width 0.3s ease;
        }
        
        /* Back to Top Button */
        .back-to-top {
            position: fixed;
            bottom: 30px;
            left: 30px;
            background: var(--accent);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
            transition: var(--transition);
            opacity: 0;
            visibility: hidden;
            z-index: 999;
        }
        
        .back-to-top.show {
            opacity: 1;
            visibility: visible;
        }
        
        .back-to-top:hover {
            background: #c0392b;
            transform: translateY(-3px);
        }
        
        /* Search Bar */
        .search-container {
            margin: 20px 0;
            display: flex;
            justify-content: center;
        }
        
        .search-box {
            width: 100%;
            max-width: 500px;
            position: relative;
        }
        
        .search-input {
            width: 100%;
            padding: 12px 50px 12px 20px;
            border: 2px solid var(--secondary);
            border-radius: 30px;
            font-size: 1rem;
            transition: var(--transition);
        }
        
        .search-input:focus {
            outline: none;
            box-shadow: 0 0 10px rgba(41, 128, 185, 0.3);
        }
        
        .search-btn {
            position: absolute;
            left: 10px;
            top: 50%;
            transform: translateY(-50%);
            background: var(--secondary);
            color: white;
            border: none;
            border-radius: 50%;
            width: 35px;
            height: 35px;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .search-btn:hover {
            background: var(--primary);
        }
        
        /* Quiz Section */
        .quiz-container {
            background: white;
            border-radius: var(--radius);
            padding: 30px;
            margin: 30px 0;
            box-shadow: var(--shadow);
        }
        
        .dark-mode .quiz-container {
            background: #2c3e50;
        }
        
        .quiz-question {
            font-size: 1.2rem;
            margin-bottom: 20px;
            color: var(--primary);
        }
        
        .quiz-options {
            list-style: none;
            padding: 0;
        }
        
        .quiz-options li {
            margin-bottom: 10px;
            padding: 10px;
            background: #f8f9fa;
            border-radius: 5px;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .dark-mode .quiz-options li {
            background: #34495e;
        }
        
        .quiz-options li:hover {
            background: #e9ecef;
        }
        
        .dark-mode .quiz-options li:hover {
            background: #3d5166;
        }
        
        .quiz-options li.selected {
            background: var(--secondary);
            color: white;
        }
        
        .quiz-result {
            margin-top: 20px;
            padding: 15px;
            border-radius: 5px;
            text-align: center;
            font-weight: bold;
            display: none;
        }
        
        .quiz-result.correct {
            background: #d4edda;
            color: #155724;
            border: 1px solid #c3e6cb;
        }
        
        .quiz-result.incorrect {
            background: #f8d7da;
            color: #721c24;
            border: 1px solid #f5c6cb;
        }
        
        /* Interactive Gallery */
        .gallery {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 15px;
            margin: 20px 0;
        }
        
        .gallery-item {
            position: relative;
            overflow: hidden;
            border-radius: var(--radius);
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
            cursor: pointer;
        }
        
        .gallery-img {
            width: 100%;
            height: 200px;
            object-fit: cover;
            transition: var(--transition);
        }
        
        .gallery-item:hover .gallery-img {
            transform: scale(1.05);
        }
        
        .gallery-caption {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            background: rgba(0, 0, 0, 0.7);
            color: white;
            padding: 10px;
            transform: translateY(100%);
            transition: var(--transition);
        }
        
        .gallery-item:hover .gallery-caption {
            transform: translateY(0);
        }
        
        /* Modal for Gallery */
        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            z-index: 1100;
            align-items: center;
            justify-content: center;
        }
        
        .modal-content {
            max-width: 90%;
            max-height: 90%;
            border-radius: var(--radius);
            overflow: hidden;
            position: relative;
        }
        
        .modal-img {
            width: 100%;
            height: auto;
            display: block;
        }
        
        .modal-close {
            position: absolute;
            top: 15px;
            left: 15px;
            background: rgba(0, 0, 0, 0.5);
            color: white;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .modal-close:hover {
            background: rgba(0, 0, 0, 0.8);
        }
        
        /* Responsive Design */
        @media (max-width: 992px) {
            .hero h2 {
                font-size: 2.3rem;
            }
            
            .section-title h2 {
                font-size: 2rem;
            }
        }
        
        @media (max-width: 768px) {
            .header-content {
                flex-direction: column;
                text-align: center;
            }
            
            nav ul {
                margin-top: 20px;
                flex-wrap: wrap;
                justify-content: center;
            }
            
            .mobile-menu {
                display: block;
                position: absolute;
                top: 20px;
                left: 20px;
            }
            
            .hero h2 {
                font-size: 2rem;
            }
            
            .hero p {
                font-size: 1.1rem;
            }
            
            .section-title h2 {
                font-size: 1.8rem;
            }
            
            .card-grid {
                grid-template-columns: 1fr;
            }
            
            .footer-content {
                flex-direction: column;
            }
        }
        
        @media (max-width: 576px) {
            .hero {
                padding: 80px 0;
            }
            
            .hero h2 {
                font-size: 1.8rem;
            }
            
            .main-content {
                padding: 60px 0;
            }
            
            .page-content h2 {
                font-size: 1.6rem;
            }
            
            .page-content h3 {
                font-size: 1.4rem;
            }
            
            .back-to-top {
                bottom: 20px;
                left: 20px;
                width: 45px;
                height: 45px;
            }
        }
        
        /* Print Styles */
        @media print {
            header, footer, .btn, .hero, .search-container, .quiz-container, .back-to-top {
                display: none;
            }
            
            body {
                font-size: 12pt;
                line-height: 1.4;
                color: #000;
                background: #fff;
            }
            
            .container {
                width: 100%;
                max-width: none;
            }
            
            .page-content {
                padding: 0;
            }
            
            .card {
                break-inside: avoid;
                box-shadow: none;
                border: 1px solid #ddd;
            }
            
            table {
                break-inside: avoid;
            }
            
            .main-content {
                padding: 20px 0;
            }
            
            .research-section {
                box-shadow: none;
                border: 1px solid #ddd;
            }
        }
        
        /* Additional Research Styles */
        .research-section {
            background: white;
            border-radius: var(--radius);
            padding: 30px;
            margin-bottom: 40px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
        }
        
        .dark-mode .research-section {
            background: #2c3e50;
        }
        
        .chapter-title {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            color: white;
            padding: 20px;
            border-radius: var(--radius);
            margin: 40px 0 25px;
            text-align: center;
            font-size: 1.8rem;
            counter-reset: subsection;
        }
        
        .reference {
            background: #f9f9f9;
            border-right: 3px solid var(--accent);
            padding: 15px;
            margin: 15px 0;
            border-radius: 5px;
        }
        
        .dark-mode .reference {
            background: #34495e;
        }
        
        .figure {
            text-align: center;
            margin: 25px 0;
        }
        
        .figure .placeholder {
            background-color: #e9ecef;
            height: 250px;
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 10px;
        }
        
        .dark-mode .figure .placeholder {
            background-color: #34495e;
        }
        
        .caption {
            font-style: italic;
            margin-top: 10px;
            color: #666;
            text-align: center;
        }
        
        .definition {
            background: #f0f7ff;
            border: 1px dashed var(--secondary);
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
        }
        
        .dark-mode .definition {
            background: #1a3a4e;
        }
        
        .teacher-info {
            background: linear-gradient(135deg, var(--info), var(--secondary));
            color: white;
            padding: 20px;
            border-radius: var(--radius);
            margin: 30px 0;
            text-align: center;
        }
        
        .teacher-info h3 {
            margin-bottom: 10px;
            font-size: 1.6rem;
        }
        
        .timeline {
            position: relative;
            max-width: 800px;
            margin: 40px auto;
        }
        
        .timeline::after {
            content: '';
            position: absolute;
            width: 6px;
            background-color: var(--secondary);
            top: 0;
            bottom: 0;
            right: 50%;
            margin-right: -3px;
        }
        
        .timeline-item {
            padding: 10px 40px;
            position: relative;
            width: 50%;
            box-sizing: border-box;
        }
        
        .timeline-item::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            background-color: white;
            border: 4px solid var(--accent);
            top: 15px;
            border-radius: 50%;
            z-index: 1;
        }
        
        .left {
            right: 0;
        }
        
        .left::after {
            left: -10px;
        }
        
        .right {
            right: 50%;
        }
        
        .right::after {
            left: -10px;
        }
        
        .timeline-content {
            padding: 20px;
            background-color: white;
            border-radius: 6px;
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
        }
        
        .dark-mode .timeline-content {
            background-color: #2c3e50;
        }
        
        .timeline-content h4 {
            margin-top: 0;
            color: var(--primary);
        }
        
        .stats {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-around;
            margin: 30px 0;
        }
        
        .stat-item {
            text-align: center;
            padding: 20px;
            flex: 1;
            min-width: 150px;
        }
        
        .stat-value {
            font-size: 2.5rem;
            font-weight: bold;
            color: var(--primary);
            display: block;
        }
        
        .stat-label {
            font-size: 1rem;
            color: var(--dark);
        }
        
        .tool-category {
            margin: 30px 0;
            padding: 20px;
            background: #f8f9fa;
            border-radius: 8px;
        }
        
        .dark-mode .tool-category {
            background: #34495e;
        }
        
        .tool-list {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 15px;
            margin-top: 15px;
        }
        
        .tool-item {
            background: white;
            padding: 15px;
            border-radius: 6px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
            border-right: 3px solid var(--secondary);
        }
        
        .dark-mode .tool-item {
            background: #2c3e50;
        }
        
        .market-analysis {
            background: white;
            border-radius: var(--radius);
            padding: 25px;
            margin: 25px 0;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }
        
        .dark-mode .market-analysis {
            background: #2c3e50;
        }
        
        .opportunity-card {
            background: white;
            border-radius: 8px;
            padding: 20px;
            margin: 15px 0;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            border-right: 4px solid var(--success);
        }
        
        .dark-mode .opportunity-card {
            background: #2c3e50;
        }
        
        .comparison-table {
            width: 100%;
            border-collapse: collapse;
            margin: 20px 0;
        }
        
        .comparison-table th, .comparison-table td {
            padding: 12px 15px;
            text-align: center;
            border: 1px solid #ddd;
        }
        
        .comparison-table th {
            background-color: var(--primary);
            color: white;
        }
        
        .comparison-table tr:nth-child(even) {
            background-color: #f8f9fa;
        }
        
        .dark-mode .comparison-table tr:nth-child(even) {
            background-color: #34495e;
        }
        
        .step-by-step {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
        }
        
        .dark-mode .step-by-step {
            background: #34495e;
        }
        
        .step {
            margin-bottom: 15px;
            padding-right: 20px;
            position: relative;
        }
        
        .step:before {
            content: counter(step);
            counter-increment: step;
            position: absolute;
            right: 0;
            top: 0;
            background: var(--accent);
            color: white;
            width: 25px;
            height: 25px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
        }
        
        .case-study {
            background: white;
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            border-left: 4px solid var(--warning);
        }
        
        .dark-mode .case-study {
            background: #2c3e50;
        }
        
        .faq-section {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
        }
        
        .dark-mode .faq-section {
            background: #34495e;
        }
        
        .faq-item {
            margin-bottom: 15px;
            padding-bottom: 15px;
            border-bottom: 1px solid #ddd;
        }
        
        .faq-question {
            font-weight: bold;
            color: var(--primary);
            margin-bottom: 5px;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .faq-question:after {
            content: '+';
            font-size: 1.2rem;
        }
        
        .faq-question.active:after {
            content: '-';
        }
        
        .faq-answer {
            display: none;
            padding-top: 10px;
        }
        
        .faq-answer.show {
            display: block;
        }
        
        .glossary {
            background: white;
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
        }
        
        .dark-mode .glossary {
            background: #2c3e50;
        }
        
        .glossary-term {
            font-weight: bold;
            color: var(--primary);
            margin-bottom: 5px;
        }
        
        .appendix {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 20px;
            margin: 20px 0;
        }
        
        .dark-mode .appendix {
            background: #34495e;
        }