:root {
            --primary-color: #2c3e50;
            --secondary-color: #3498db;
            --accent-color: #e74c3c;
            --light-color: #ecf0f1;
            --dark-color: #2c3e50;
            --text-color: #333;
            --border-radius: 8px;
            --box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            --transition: all 0.3s ease;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Nirmala UI', 'Arial', sans-serif;
        }
        body {
            line-height: 1.7;
            color: var(--text-color);
            background-color: #f9f9f9;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        header {
            background-color: var(--primary-color);
            color: white;
            padding: 1rem 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            text-decoration: none;
            color: white;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .logo span {
            color: var(--secondary-color);
        }
        .logo:hover {
            color: var(--light-color);
        }
        .desktop-nav ul {
            display: flex;
            list-style: none;
            gap: 1.5rem;
        }
        .desktop-nav a {
            color: white;
            text-decoration: none;
            font-weight: 500;
            padding: 0.5rem 0.8rem;
            border-radius: var(--border-radius);
            transition: var(--transition);
        }
        .desktop-nav a:hover,
        .desktop-nav a.active {
            background-color: var(--secondary-color);
            color: white;
        }
        .hamburger {
            display: none;
            font-size: 1.5rem;
            background: none;
            border: none;
            color: white;
            cursor: pointer;
        }
        .mobile-nav {
            display: none;
            position: fixed;
            top: 70px;
            left: 0;
            width: 100%;
            background-color: var(--primary-color);
            padding: 1rem;
            box-shadow: 0 5px 10px rgba(0,0,0,0.1);
            z-index: 999;
        }
        .mobile-nav.active {
            display: block;
        }
        .mobile-nav ul {
            list-style: none;
        }
        .mobile-nav a {
            display: block;
            color: white;
            text-decoration: none;
            padding: 0.8rem 1rem;
            border-bottom: 1px solid rgba(255,255,255,0.1);
            transition: var(--transition);
        }
        .mobile-nav a:hover {
            background-color: var(--secondary-color);
            padding-left: 1.5rem;
        }
        .breadcrumb {
            padding: 1rem 0;
            background-color: var(--light-color);
            font-size: 0.9rem;
        }
        .breadcrumb ol {
            display: flex;
            list-style: none;
            flex-wrap: wrap;
            gap: 0.5rem;
        }
        .breadcrumb li {
            display: flex;
            align-items: center;
        }
        .breadcrumb a {
            color: var(--secondary-color);
            text-decoration: none;
        }
        .breadcrumb a:hover {
            text-decoration: underline;
        }
        .breadcrumb li:not(:last-child)::after {
            content: "›";
            margin-left: 0.5rem;
            color: #777;
        }
        main {
            padding: 2rem 0;
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 2rem;
        }
        .article-content {
            background-color: white;
            padding: 2rem;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }
        .article-content h1 {
            font-size: 2.2rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            line-height: 1.3;
        }
        .article-content h2 {
            font-size: 1.8rem;
            color: var(--dark-color);
            margin: 2rem 0 1rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--secondary-color);
        }
        .article-content h3 {
            font-size: 1.4rem;
            color: var(--dark-color);
            margin: 1.5rem 0 0.8rem;
        }
        .article-content p {
            margin-bottom: 1.2rem;
            text-align: justify;
        }
        .article-content strong {
            color: var(--primary-color);
            font-weight: 700;
        }
        .article-content em {
            color: var(--accent-color);
            font-style: italic;
        }
        .highlight-box {
            background-color: #f8f9fa;
            border-left: 4px solid var(--secondary-color);
            padding: 1.5rem;
            margin: 1.5rem 0;
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
        }
        .code-block {
            background-color: #2d2d2d;
            color: #f8f8f2;
            padding: 1.5rem;
            border-radius: var(--border-radius);
            overflow-x: auto;
            margin: 1.5rem 0;
            font-family: 'Consolas', 'Monaco', monospace;
            font-size: 0.95rem;
            line-height: 1.5;
        }
        .sudoku-grid {
            display: grid;
            grid-template-columns: repeat(9, 1fr);
            gap: 2px;
            max-width: 400px;
            margin: 1.5rem auto;
            background-color: #333;
            padding: 5px;
            border-radius: 4px;
        }
        .sudoku-cell {
            aspect-ratio: 1;
            background-color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            font-size: 1.2rem;
            border: 1px solid #ddd;
        }
        .sudoku-cell.fixed {
            background-color: #f0f0f0;
            color: #000;
        }
        aside {
            display: flex;
            flex-direction: column;
            gap: 1.5rem;
        }
        .sidebar-widget {
            background-color: white;
            padding: 1.5rem;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }
        .sidebar-widget h3 {
            color: var(--primary-color);
            margin-bottom: 1rem;
            padding-bottom: 0.5rem;
            border-bottom: 1px solid #eee;
        }
        .search-form {
            display: flex;
            margin-top: 1rem;
        }
        .search-form input {
            flex: 1;
            padding: 0.8rem;
            border: 1px solid #ddd;
            border-radius: var(--border-radius) 0 0 var(--border-radius);
            font-size: 1rem;
        }
        .search-form button {
            background-color: var(--secondary-color);
            color: white;
            border: none;
            padding: 0 1.2rem;
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
            cursor: pointer;
            transition: var(--transition);
        }
        .search-form button:hover {
            background-color: #2980b9;
        }
        .rating-widget {
            text-align: center;
        }
        .stars {
            display: flex;
            justify-content: center;
            gap: 0.3rem;
            margin: 1rem 0;
            font-size: 1.8rem;
            color: #ffd700;
        }
        .stars i {
            cursor: pointer;
            transition: var(--transition);
        }
        .stars i:hover {
            transform: scale(1.2);
        }
        .comment-form textarea {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #ddd;
            border-radius: var(--border-radius);
            font-size: 1rem;
            resize: vertical;
            min-height: 120px;
            margin-bottom: 1rem;
        }
        .comment-form button {
            background-color: var(--secondary-color);
            color: white;
            border: none;
            padding: 0.8rem 1.5rem;
            border-radius: var(--border-radius);
            cursor: pointer;
            font-weight: 600;
            transition: var(--transition);
            width: 100%;
        }
        .comment-form button:hover {
            background-color: #2980b9;
        }
        .article-image {
            width: 100%;
            max-width: 600px;
            height: auto;
            border-radius: var(--border-radius);
            margin: 1.5rem auto;
            display: block;
            box-shadow: var(--box-shadow);
        }
        .footer-links {
            background-color: var(--light-color);
            padding: 2rem 0;
            margin-top: 2rem;
        }
        .web-links-container {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 1rem;
        }
        .web-link {
            background-color: white;
            padding: 1rem;
            border-radius: var(--border-radius);
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
            transition: var(--transition);
        }
        .web-link:hover {
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .web-link a {
            color: var(--secondary-color);
            text-decoration: none;
            font-weight: 500;
            display: block;
        }
        .web-link a:hover {
            text-decoration: underline;
        }
        footer {
            background-color: var(--primary-color);
            color: white;
            padding: 2rem 0;
            text-align: center;
        }
        .footer-container {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 1rem;
        }
        .social-links {
            display: flex;
            gap: 1rem;
            margin: 1rem 0;
        }
        .social-links a {
            color: white;
            font-size: 1.5rem;
            transition: var(--transition);
        }
        .social-links a:hover {
            color: var(--secondary-color);
            transform: translateY(-3px);
        }
        .copyright {
            font-size: 0.9rem;
            color: #bbb;
            margin-top: 1rem;
        }
        @media (max-width: 992px) {
            main {
                grid-template-columns: 1fr;
            }
        }
        @media (max-width: 768px) {
            .desktop-nav {
                display: none;
            }
            .hamburger {
                display: block;
            }
            .article-content h1 {
                font-size: 1.8rem;
            }
            .article-content h2 {
                font-size: 1.5rem;
            }
            .sudoku-grid {
                max-width: 300px;
                grid-template-columns: repeat(9, 1fr);
            }
            .sudoku-cell {
                font-size: 0.9rem;
            }
            .header-container, .breadcrumb ol {
                padding: 0 15px;
            }
        }
        @media (max-width: 480px) {
            .article-content {
                padding: 1.5rem;
            }
            .sidebar-widget {
                padding: 1.2rem;
            }
            .web-links-container {
                grid-template-columns: 1fr;
            }
        }
        .interactive-demo {
            background-color: #f0f7ff;
            border: 2px dashed var(--secondary-color);
            border-radius: var(--border-radius);
            padding: 1.5rem;
            margin: 2rem 0;
            transition: var(--transition);
        }
        .interactive-demo:hover {
            background-color: #e1f0ff;
        }
        .btn {
            display: inline-block;
            background-color: var(--secondary-color);
            color: white;
            padding: 0.7rem 1.5rem;
            border-radius: var(--border-radius);
            text-decoration: none;
            font-weight: 600;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            margin: 0.5rem 0;
        }
        .btn:hover {
            background-color: #2980b9;
            transform: translateY(-2px);
            box-shadow: 0 5px 10px rgba(0,0,0,0.1);
        }
        .btn-accent {
            background-color: var(--accent-color);
        }
        .btn-accent:hover {
            background-color: #c0392b;
        }
        @media print {
            .sidebar-widget, .footer-links, .mobile-nav, .hamburger, .social-links {
                display: none !important;
            }
            main {
                display: block;
            }
            .article-content {
                box-shadow: none;
                padding: 0;
            }
        }