:root {
            --primary-color: #1a365d;
            --secondary-color: #e53e3e;
            --accent-color: #38b2ac;
            --light-bg: #f7fafc;
            --dark-text: #2d3748;
            --light-text: #718096;
            --border-color: #e2e8f0;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--dark-text);
            background-color: var(--light-bg);
            max-width: 100vw;
            overflow-x: hidden;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }
        .container {
            width: 100%;
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .visually-hidden {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }
        header {
            background-color: white;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .top-bar {
            background: linear-gradient(to right, var(--primary-color), #2d4a8a);
            color: white;
            padding: 8px 0;
            font-size: 0.9rem;
        }
        .top-bar .container {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .last-updated {
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .utility-nav a {
            margin-left: 15px;
            color: #cbd5e0;
        }
        .utility-nav a:hover {
            color: white;
        }
        .main-header {
            padding: 15px 0;
        }
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .my-logo {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--primary-color);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .my-logo i {
            color: var(--secondary-color);
        }
        .my-logo span {
            background: linear-gradient(45deg, var(--primary-color), var(--accent-color));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .search-box {
            display: flex;
            max-width: 400px;
            flex-grow: 1;
            margin: 0 30px;
        }
        .search-box input {
            flex-grow: 1;
            padding: 12px 20px;
            border: 2px solid var(--border-color);
            border-radius: 50px 0 0 50px;
            font-size: 1rem;
            outline: none;
            transition: var(--transition);
        }
        .search-box input:focus {
            border-color: var(--accent-color);
        }
        .search-box button {
            background-color: var(--primary-color);
            color: white;
            border: none;
            padding: 0 25px;
            border-radius: 0 50px 50px 0;
            cursor: pointer;
            transition: var(--transition);
        }
        .search-box button:hover {
            background-color: var(--secondary-color);
        }
        .desktop-nav {
            display: flex;
            gap: 25px;
        }
        @media (min-width: 1025px) {
            .desktop-nav {
                display: flex;
            }
            .hamburger {
                display: none;
            }
        }
        .desktop-nav a {
            font-weight: 600;
            color: var(--dark-text);
            position: relative;
            padding: 5px 0;
        }
        .desktop-nav a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background-color: var(--secondary-color);
            transition: var(--transition);
        }
        .desktop-nav a:hover::after,
        .desktop-nav a.active::after {
            width: 100%;
        }
        .desktop-nav a:hover {
            color: var(--secondary-color);
        }
        .hamburger {
            background: none;
            border: none;
            font-size: 1.8rem;
            color: var(--primary-color);
            cursor: pointer;
            display: none;
        }
        .mobile-nav {
            position: fixed;
            top: 0;
            right: -300px;
            width: 280px;
            height: 100vh;
            background-color: white;
            box-shadow: -5px 0 15px rgba(0,0,0,0.1);
            padding: 20px;
            z-index: 1001;
            transition: var(--transition);
            overflow-y: auto;
        }
        .mobile-nav.active {
            right: 0;
        }
        .mobile-nav-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 30px;
            padding-bottom: 15px;
            border-bottom: 1px solid var(--border-color);
        }
        .close-menu {
            background: none;
            border: none;
            font-size: 1.5rem;
            color: var(--dark-text);
            cursor: pointer;
        }
        .mobile-nav-links {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }
        .mobile-nav-links a {
            padding: 12px 15px;
            border-radius: 8px;
            font-weight: 600;
        }
        .mobile-nav-links a:hover {
            background-color: var(--light-bg);
            color: var(--secondary-color);
        }
        .overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0,0,0,0.5);
            z-index: 1000;
            display: none;
        }
        .overlay.active {
            display: block;
        }
        @media (max-width: 1024px) {
            .desktop-nav {
                display: none;
            }
            .hamburger {
                display: block;
            }
            .search-box {
                margin: 0 15px;
                max-width: 300px;
            }
        }
        @media (max-width: 768px) {
            .header-content {
                flex-wrap: wrap;
                gap: 15px;
            }
            .search-box {
                order: 3;
                width: 100%;
                max-width: 100%;
                margin: 10px 0 0 0;
            }
        }
        .breadcrumb {
            padding: 15px 0;
            background-color: #edf2f7;
            font-size: 0.9rem;
        }
        .breadcrumb .container {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 8px;
        }
        .breadcrumb a {
            color: var(--light-text);
        }
        .breadcrumb a:hover {
            color: var(--secondary-color);
        }
        .breadcrumb i {
            margin: 0 5px;
            color: var(--light-text);
            font-size: 0.8rem;
        }
        main {
            padding: 40px 0;
        }
        .article-header {
            text-align: center;
            margin-bottom: 50px;
            padding-bottom: 30px;
            border-bottom: 1px solid var(--border-color);
        }
        h1 {
            font-size: 2.8rem;
            color: var(--primary-color);
            margin-bottom: 20px;
            line-height: 1.2;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
        }
        .article-meta {
            display: flex;
            justify-content: center;
            align-items: center;
            flex-wrap: wrap;
            gap: 20px;
            color: var(--light-text);
            font-size: 0.95rem;
        }
        .article-meta span {
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .content-grid {
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 40px;
        }
        @media (max-width: 1024px) {
            .content-grid {
                grid-template-columns: 1fr;
            }
        }
        .article-content {
            background-color: white;
            padding: 40px;
            border-radius: 12px;
            box-shadow: var(--shadow);
        }
        h2 {
            font-size: 2rem;
            color: var(--primary-color);
            margin: 40px 0 20px;
            padding-bottom: 10px;
            border-bottom: 3px solid var(--accent-color);
        }
        h3 {
            font-size: 1.6rem;
            color: var(--dark-text);
            margin: 30px 0 15px;
        }
        h4 {
            font-size: 1.3rem;
            color: var(--secondary-color);
            margin: 25px 0 12px;
        }
        p {
            margin-bottom: 20px;
            text-align: justify;
        }
        .lead {
            font-size: 1.2rem;
            font-weight: 500;
            color: var(--primary-color);
            background-color: #ebf8ff;
            padding: 20px;
            border-left: 5px solid var(--accent-color);
            border-radius: 0 8px 8px 0;
            margin-bottom: 30px;
        }
        .highlight {
            background-color: #fff5f5;
            padding: 20px;
            border-radius: 8px;
            margin: 25px 0;
            border-left: 5px solid var(--secondary-color);
        }
        .highlight p:last-child {
            margin-bottom: 0;
        }
        .info-box {
            background-color: #f0fff4;
            border-left: 5px solid #38a169;
            padding: 20px;
            border-radius: 0 8px 8px 0;
            margin: 25px 0;
        }
        .img-container {
            margin: 30px 0;
            text-align: center;
        }
        .featured-img {
            max-width: 100%;
            height: auto;
            border-radius: 12px;
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            transition: var(--transition);
        }
        .featured-img:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .img-caption {
            font-size: 0.9rem;
            color: var(--light-text);
            margin-top: 10px;
            font-style: italic;
        }
        ul, ol {
            margin-left: 25px;
            margin-bottom: 20px;
        }
        li {
            margin-bottom: 8px;
        }
        blockquote {
            font-style: italic;
            color: var(--primary-color);
            border-left: 4px solid var(--accent-color);
            padding-left: 20px;
            margin: 25px 0;
        }
        .quote-author {
            text-align: right;
            font-weight: 600;
            color: var(--secondary-color);
            margin-top: 10px;
        }
        .key-term {
            font-weight: 700;
            color: var(--secondary-color);
        }
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin: 30px 0;
        }
        .stat-card {
            background: white;
            padding: 20px;
            border-radius: 10px;
            text-align: center;
            box-shadow: var(--shadow);
            border-top: 5px solid var(--accent-color);
        }
        .stat-number {
            font-size: 2.5rem;
            font-weight: 800;
            color: var(--primary-color);
            line-height: 1;
            margin-bottom: 10px;
        }
        .stat-label {
            color: var(--light-text);
            font-size: 0.95rem;
        }
        .link-list {
            background-color: #f8f9fa;
            padding: 25px;
            border-radius: 10px;
            margin: 30px 0;
        }
        .link-list h4 {
            margin-top: 0;
        }
        .link-list ul {
            columns: 2;
            column-gap: 30px;
        }
        @media (max-width: 768px) {
            .link-list ul {
                columns: 1;
            }
        }
        .link-list a {
            color: var(--primary-color);
            text-decoration: underline;
        }
        .link-list a:hover {
            color: var(--secondary-color);
        }
        .sidebar {
            display: flex;
            flex-direction: column;
            gap: 30px;
        }
        .sidebar-widget {
            background-color: white;
            padding: 25px;
            border-radius: 12px;
            box-shadow: var(--shadow);
        }
        .sidebar-widget h3 {
            font-size: 1.4rem;
            margin-top: 0;
            padding-bottom: 15px;
            border-bottom: 2px solid var(--border-color);
        }
        .rating-widget {
            text-align: center;
        }
        .stars {
            font-size: 2rem;
            color: #ffd700;
            margin: 15px 0;
            cursor: pointer;
        }
        .stars i {
            margin: 0 3px;
            transition: var(--transition);
        }
        .stars i:hover {
            transform: scale(1.2);
        }
        .rating-form input, .comment-form input, .comment-form textarea {
            width: 100%;
            padding: 12px 15px;
            margin-bottom: 15px;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            font-size: 1rem;
            transition: var(--transition);
        }
        .rating-form input:focus, .comment-form input:focus, .comment-form textarea:focus {
            outline: none;
            border-color: var(--accent-color);
        }
        .rating-form button, .comment-form button {
            width: 100%;
            padding: 14px;
            background-color: var(--primary-color);
            color: white;
            border: none;
            border-radius: 8px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
        }
        .rating-form button:hover, .comment-form button:hover {
            background-color: var(--secondary-color);
        }
        .toc {
            position: sticky;
            top: 120px;
        }
        .toc ul {
            list-style: none;
            margin-left: 0;
        }
        .toc li {
            margin-bottom: 12px;
        }
        .toc a {
            display: block;
            padding: 10px 15px;
            border-radius: 8px;
            color: var(--dark-text);
            border-left: 3px solid transparent;
        }
        .toc a:hover, .toc a.active {
            background-color: var(--light-bg);
            border-left-color: var(--secondary-color);
            color: var(--secondary-color);
        }
        .popular-links ul {
            list-style: none;
            margin-left: 0;
        }
        .popular-links li {
            padding: 12px 0;
            border-bottom: 1px dashed var(--border-color);
        }
        .popular-links li:last-child {
            border-bottom: none;
        }
        .popular-links a {
            color: var(--dark-text);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .popular-links a:hover {
            color: var(--secondary-color);
        }
        .popular-links i {
            color: var(--accent-color);
        }
        .comments-section {
            margin-top: 60px;
            background-color: white;
            padding: 40px;
            border-radius: 12px;
            box-shadow: var(--shadow);
        }
        .comment {
            padding: 25px 0;
            border-bottom: 1px solid var(--border-color);
        }
        .comment:last-child {
            border-bottom: none;
        }
        .comment-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 15px;
            flex-wrap: wrap;
            gap: 10px;
        }
        .comment-author {
            font-weight: 700;
            color: var(--primary-color);
        }
        .comment-date {
            color: var(--light-text);
            font-size: 0.9rem;
        }
        .comment-rating {
            color: #ffd700;
        }
        footer {
            background-color: var(--primary-color);
            color: white;
            padding: 60px 0 30px;
            margin-top: 60px;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 40px;
            margin-bottom: 40px;
        }
        @media (max-width: 992px) {
            .footer-content {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        @media (max-width: 576px) {
            .footer-content {
                grid-template-columns: 1fr;
            }
        }
        .footer-logo {
            font-size: 1.8rem;
            font-weight: 800;
            margin-bottom: 20px;
            display: block;
        }
        .footer-about p {
            color: #cbd5e0;
        }
        .footer-links h4, .footer-social h4 {
            font-size: 1.2rem;
            margin-bottom: 25px;
            position: relative;
            padding-bottom: 10px;
        }
        .footer-links h4::after, .footer-social h4::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 50px;
            height: 3px;
            background-color: var(--secondary-color);
        }
        .footer-links ul {
            list-style: none;
            margin-left: 0;
        }
        .footer-links li {
            margin-bottom: 12px;
        }
        .footer-links a {
            color: #cbd5e0;
        }
        .footer-links a:hover {
            color: white;
            padding-left: 8px;
        }
        .social-icons {
            display: flex;
            gap: 15px;
            margin-top: 20px;
        }
        .social-icons a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background-color: rgba(255,255,255,0.1);
            border-radius: 50%;
            color: white;
            font-size: 1.2rem;
            transition: var(--transition);
        }
        .social-icons a:hover {
            background-color: var(--secondary-color);
            transform: translateY(-5px);
        }
        .friend-links {
            background-color: rgba(255,255,255,0.05);
            padding: 25px;
            border-radius: 10px;
            margin-bottom: 30px;
        }
        friend-link {
            display: inline-block;
            margin-right: 20px;
            margin-bottom: 10px;
        }
        friend-link a {
            color: #90cdf4;
        }
        friend-link a:hover {
            color: white;
            text-decoration: underline;
        }
        .copyright {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(255,255,255,0.1);
            color: #a0aec0;
            font-size: 0.9rem;
        }