:root {
            --primary: #FF6B35; 
            --primary-dark: #E55A2B;
            --secondary: #2A3D66; 
            --accent: #00C9B7; 
            --light: #F7F9FC;
            --dark: #1A1A2E;
            --gray: #6C757D;
            --shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
            --border-radius: 12px;
        }
        * {
            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: #333;
            background-color: #fefefe;
            overflow-x: hidden;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }
        ul {
            list-style: none;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
            border-radius: var(--border-radius);
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .btn {
            display: inline-block;
            padding: 12px 28px;
            background: linear-gradient(to right, var(--primary), var(--primary-dark));
            color: white;
            border-radius: 50px;
            font-weight: 600;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
        }
        .btn:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow);
            background: linear-gradient(to right, var(--primary-dark), var(--primary));
        }
        .btn-secondary {
            background: var(--secondary);
        }
        .btn-secondary:hover {
            background: #1e2d4d;
        }
        .site-header {
            background-color: white;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 20px;
        }
        .logo a {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--primary);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .logo i {
            color: var(--accent);
        }
        .desktop-nav ul {
            display: flex;
            gap: 30px;
        }
        .desktop-nav a {
            font-weight: 600;
            color: var(--dark);
            padding: 8px 0;
            position: relative;
        }
        .desktop-nav a:hover {
            color: var(--primary);
        }
        .desktop-nav a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background: var(--primary);
            transition: width 0.3s;
        }
        .desktop-nav a:hover::after {
            width: 100%;
        }
        .mobile-toggle {
            display: none;
            font-size: 1.5rem;
            cursor: pointer;
            color: var(--dark);
        }
        .mobile-nav {
            position: fixed;
            top: 70px;
            left: 0;
            width: 100%;
            background: white;
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            padding: 20px;
            transform: translateY(-150%);
            opacity: 0;
            transition: transform 0.5s ease, opacity 0.3s;
            z-index: 999;
        }
        .mobile-nav.active {
            transform: translateY(0);
            opacity: 1;
        }
        .mobile-nav ul {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }
        .mobile-nav a {
            display: block;
            padding: 12px;
            border-radius: 8px;
            font-weight: 600;
            color: var(--dark);
            border-left: 4px solid transparent;
        }
        .mobile-nav a:hover,
        .mobile-nav a.active {
            background: var(--light);
            border-left-color: var(--primary);
            color: var(--primary);
        }
        .breadcrumb {
            padding: 15px 0;
            background-color: var(--light);
            font-size: 0.9rem;
            margin-bottom: 30px;
        }
        .breadcrumb ol {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
        }
        .breadcrumb li:not(:last-child)::after {
            content: '/';
            margin-left: 10px;
            color: var(--gray);
        }
        .breadcrumb a {
            color: var(--gray);
        }
        .breadcrumb a:hover {
            color: var(--primary);
        }
        .breadcrumb .current {
            color: var(--primary);
            font-weight: 600;
        }
        .main-content {
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 40px;
            padding: 30px 0 50px;
        }
        @media (max-width: 992px) {
            .main-content {
                grid-template-columns: 1fr;
            }
        }
        .article-content {
            background: white;
            padding: 30px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
        }
        .article-header {
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 2px solid var(--light);
        }
        h1 {
            font-size: 2.5rem;
            color: var(--dark);
            margin-bottom: 15px;
            line-height: 1.2;
        }
        .article-meta {
            display: flex;
            gap: 20px;
            color: var(--gray);
            font-size: 0.9rem;
        }
        .article-meta span {
            display: flex;
            align-items: center;
            gap: 5px;
        }
        h2 {
            font-size: 1.8rem;
            color: var(--secondary);
            margin: 40px 0 20px;
            padding-bottom: 10px;
            border-bottom: 1px dashed #ddd;
        }
        h3 {
            font-size: 1.4rem;
            color: var(--primary);
            margin: 30px 0 15px;
        }
        h4 {
            font-size: 1.2rem;
            color: var(--accent);
            margin: 25px 0 10px;
        }
        p {
            margin-bottom: 20px;
            text-align: justify;
        }
        .highlight {
            background-color: #fff9e6;
            border-left: 4px solid #ffc107;
            padding: 20px;
            margin: 25px 0;
            border-radius: 0 8px 8px 0;
        }
        .image-caption {
            text-align: center;
            font-style: italic;
            color: var(--gray);
            margin-top: 10px;
            font-size: 0.9rem;
        }
        .featured-image {
            margin: 30px 0;
        }
        ul.content-list {
            list-style: disc inside;
            margin-left: 20px;
            margin-bottom: 20px;
        }
        .content-list li {
            margin-bottom: 10px;
            padding-left: 5px;
        }
        .tip-box {
            background: #e8f4fd;
            border: 1px solid #b6e0fe;
            border-radius: var(--border-radius);
            padding: 20px;
            margin: 25px 0;
            display: flex;
            gap: 15px;
            align-items: flex-start;
        }
        .tip-box i {
            color: var(--accent);
            font-size: 1.5rem;
            flex-shrink: 0;
        }
        .note-box {
            background: #f0f7ff;
            border-left: 4px solid var(--accent);
            padding: 15px 20px;
            margin: 25px 0;
        }
        .key-term {
            font-weight: bold;
            color: var(--primary-dark);
        }
        .sidebar {
            display: flex;
            flex-direction: column;
            gap: 30px;
        }
        .sidebar-widget {
            background: white;
            padding: 25px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
        }
        .widget-title {
            font-size: 1.3rem;
            color: var(--secondary);
            margin-bottom: 20px;
            padding-bottom: 10px;
            border-bottom: 2px solid var(--light);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .widget-title i {
            color: var(--primary);
        }
        .search-form {
            display: flex;
        }
        .search-form input {
            flex: 1;
            padding: 12px 15px;
            border: 1px solid #ddd;
            border-radius: 50px 0 0 50px;
            outline: none;
            font-size: 1rem;
        }
        .search-form button {
            background: var(--primary);
            color: white;
            border: none;
            padding: 0 20px;
            border-radius: 0 50px 50px 0;
            cursor: pointer;
            transition: var(--transition);
        }
        .search-form button:hover {
            background: var(--primary-dark);
        }
        .related-links ul {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .related-links a {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 12px 15px;
            background: var(--light);
            border-radius: 8px;
            color: var(--dark);
        }
        .related-links a:hover {
            background: #e9ecef;
            transform: translateX(5px);
            color: var(--primary);
        }
        .related-links i {
            color: var(--accent);
        }
        .rating-widget {
            text-align: center;
        }
        .stars {
            display: flex;
            justify-content: center;
            gap: 5px;
            margin: 15px 0;
            font-size: 1.8rem;
            color: #ffc107;
        }
        .stars i {
            cursor: pointer;
            transition: var(--transition);
        }
        .stars i:hover {
            transform: scale(1.2);
        }
        .rating-form input,
        .rating-form textarea {
            width: 100%;
            padding: 12px;
            margin-bottom: 15px;
            border: 1px solid #ddd;
            border-radius: 8px;
            font-family: inherit;
        }
        .rating-form textarea {
            min-height: 100px;
            resize: vertical;
        }
        .comments-section {
            margin-top: 50px;
            background: white;
            padding: 30px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
        }
        .comments-list {
            margin-top: 30px;
        }
        .comment {
            padding: 20px;
            border-bottom: 1px solid #eee;
            display: flex;
            gap: 15px;
        }
        .comment:last-child {
            border-bottom: none;
        }
        .comment-avatar {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background: var(--light);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            color: var(--gray);
            flex-shrink: 0;
        }
        .comment-content h5 {
            color: var(--secondary);
            margin-bottom: 5px;
        }
        .comment-meta {
            color: var(--gray);
            font-size: 0.85rem;
            margin-bottom: 10px;
        }
        site-footer {
            background: var(--dark);
            color: white;
            padding: 50px 0 20px;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-bottom: 40px;
        }
        .footer-logo {
            font-size: 1.8rem;
            font-weight: 800;
            color: white;
            margin-bottom: 15px;
            display: block;
        }
        .footer-about p {
            color: #bbb;
            margin-bottom: 20px;
        }
        .social-links {
            display: flex;
            gap: 15px;
        }
        .social-links a {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: rgba(255,255,255,0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: var(--transition);
        }
        .social-links a:hover {
            background: var(--primary);
            transform: translateY(-5px);
        }
        .footer-links h4 {
            color: white;
            margin-bottom: 20px;
            font-size: 1.2rem;
        }
        .footer-links ul {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .footer-links a {
            color: #bbb;
        }
        .footer-links a:hover {
            color: var(--primary);
            padding-left: 5px;
        }
        friend-link {
            display: block;
            margin-top: 10px;
            padding-top: 10px;
            border-top: 1px solid rgba(255,255,255,0.1);
        }
        .copyright {
            text-align: center;
            padding-top: 20px;
            border-top: 1px solid rgba(255,255,255,0.1);
            color: #bbb;
            font-size: 0.9rem;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }
            h2 {
                font-size: 1.5rem;
            }
            .header-container {
                padding: 15px;
            }
            .desktop-nav {
                display: none;
            }
            .mobile-toggle {
                display: block;
            }
            .article-content,
            .sidebar-widget,
            .comments-section {
                padding: 20px;
            }
            .main-content {
                gap: 30px;
            }
            .footer-content {
                grid-template-columns: 1fr;
            }
        }