* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        :root {
            --primary: #3a6ea5;
            --secondary: #c0d6df;
            --accent: #ff6b6b;
            --dark: #2a3d45;
            --light: #f8f9fa;
            --text: #333333;
            --gray: #6c757d;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.8;
            color: var(--text);
            background-color: #fff;
            max-width: 1920px;
            margin: 0 auto;
            overflow-x: hidden;
        }
        h1, h2, h3, h4 {
            font-family: 'Georgia', serif;
            color: var(--dark);
            margin-bottom: 1.5rem;
            line-height: 1.3;
        }
        h1 {
            font-size: clamp(2.5rem, 5vw, 3.5rem);
            border-left: 6px solid var(--accent);
            padding-left: 1.5rem;
            margin-top: 2rem;
        }
        h2 {
            font-size: clamp(1.8rem, 4vw, 2.5rem);
            padding-bottom: 0.5rem;
            border-bottom: 3px solid var(--secondary);
            margin-top: 3rem;
        }
        h3 {
            font-size: clamp(1.4rem, 3vw, 1.8rem);
            color: var(--primary);
            margin-top: 2.5rem;
        }
        p {
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        header {
            background-color: var(--light);
            box-shadow: 0 4px 12px rgba(0,0,0,0.08);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 0;
        }
        .logo a {
            font-size: 2.2rem;
            font-weight: 700;
            color: var(--primary);
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .logo-icon {
            color: var(--accent);
            font-size: 2.5rem;
        }
        .desktop-nav {
            display: flex;
            gap: 2rem;
        }
        .desktop-nav a {
            text-decoration: none;
            color: var(--dark);
            font-weight: 600;
            font-size: 1.1rem;
            padding: 0.5rem 1rem;
            border-radius: 4px;
            transition: var(--transition);
        }
        .desktop-nav a:hover {
            background-color: var(--secondary);
            color: var(--primary);
        }
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 1.8rem;
            color: var(--primary);
            cursor: pointer;
        }
        .mobile-nav {
            display: none;
            flex-direction: column;
            background-color: var(--light);
            padding: 1.5rem;
            position: absolute;
            top: 100%;
            left: 0;
            right: 0;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        .mobile-nav.active {
            display: flex;
        }
        .mobile-nav a {
            padding: 1rem;
            text-decoration: none;
            color: var(--dark);
            font-weight: 600;
            border-bottom: 1px solid #eee;
        }
        .mobile-nav a:last-child {
            border-bottom: none;
        }
        .mobile-nav a:hover {
            background-color: var(--secondary);
            padding-left: 1.5rem;
        }
        .breadcrumb {
            padding: 1.5rem 0;
            background-color: #f5f7fa;
            margin-bottom: 2rem;
        }
        .breadcrumb ul {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 0.8rem;
        }
        .breadcrumb li:not(:last-child)::after {
            content: "›";
            margin-left: 0.8rem;
            color: var(--gray);
        }
        .breadcrumb a {
            text-decoration: none;
            color: var(--primary);
            transition: var(--transition);
        }
        .breadcrumb a:hover {
            text-decoration: underline;
        }
        .search-container {
            background: linear-gradient(135deg, var(--secondary), #e1ecf4);
            padding: 2.5rem;
            border-radius: 12px;
            margin: 3rem 0;
            text-align: center;
        }
        .search-form {
            max-width: 700px;
            margin: 0 auto;
            display: flex;
            gap: 10px;
        }
        .search-input {
            flex: 1;
            padding: 1.2rem 1.5rem;
            border: 2px solid var(--primary);
            border-radius: 8px;
            font-size: 1.1rem;
            transition: var(--transition);
        }
        .search-input:focus {
            outline: none;
            border-color: var(--accent);
            box-shadow: 0 0 0 3px rgba(255,107,107,0.2);
        }
        .search-btn {
            background-color: var(--primary);
            color: white;
            border: none;
            padding: 0 2rem;
            border-radius: 8px;
            cursor: pointer;
            font-size: 1.1rem;
            font-weight: 600;
            transition: var(--transition);
        }
        .search-btn:hover {
            background-color: #2d5985;
            transform: translateY(-2px);
        }
        .content-grid {
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 3rem;
            margin: 3rem 0;
        }
        @media (max-width: 992px) {
            .content-grid {
                grid-template-columns: 1fr;
            }
        }
        main {
            min-height: 2000px;
        }
        .article-intro {
            background: linear-gradient(to right, #f8f9fa, #ffffff);
            padding: 2.5rem;
            border-radius: 10px;
            margin-bottom: 3rem;
            border-left: 5px solid var(--accent);
        }
        .highlight-box {
            background-color: #fff9e6;
            border: 2px dashed #ffcc00;
            padding: 2rem;
            border-radius: 10px;
            margin: 2.5rem 0;
        }
        .puzzle-image {
            width: 100%;
            max-width: 800px;
            height: auto;
            border-radius: 12px;
            margin: 2.5rem auto;
            display: block;
            box-shadow: 0 10px 30px rgba(0,0,0,0.15);
            transition: var(--transition);
        }
        .puzzle-image:hover {
            transform: scale(1.01);
            box-shadow: 0 15px 40px rgba(0,0,0,0.2);
        }
        .image-caption {
            text-align: center;
            font-style: italic;
            color: var(--gray);
            margin-top: 0.5rem;
            font-size: 0.95rem;
        }
        sidebar {
            background-color: var(--light);
            padding: 2rem;
            border-radius: 12px;
            height: fit-content;
            position: sticky;
            top: 120px;
            box-shadow: 0 5px 20px rgba(0,0,0,0.05);
        }
        .sidebar-section {
            margin-bottom: 2.5rem;
        }
        .sidebar-section h3 {
            font-size: 1.3rem;
            color: var(--dark);
            margin-bottom: 1.2rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--secondary);
        }
        .sidebar-list {
            list-style: none;
        }
        .sidebar-list li {
            padding: 0.8rem 0;
            border-bottom: 1px dashed #ddd;
        }
        .sidebar-list li:last-child {
            border-bottom: none;
        }
        .sidebar-list a {
            text-decoration: none;
            color: var(--text);
            transition: var(--transition);
            display: block;
        }
        .sidebar-list a:hover {
            color: var(--primary);
            padding-left: 8px;
        }
        .user-interaction {
            background-color: #f8fafc;
            border-radius: 12px;
            padding: 2.5rem;
            margin: 4rem 0;
            border: 1px solid #e2e8f0;
        }
        .interaction-tabs {
            display: flex;
            border-bottom: 2px solid var(--secondary);
            margin-bottom: 2rem;
        }
        .tab-btn {
            padding: 1rem 2rem;
            background: none;
            border: none;
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--gray);
            cursor: pointer;
            transition: var(--transition);
            position: relative;
        }
        .tab-btn.active {
            color: var(--primary);
        }
        .tab-btn.active::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            right: 0;
            height: 3px;
            background-color: var(--primary);
        }
        .tab-content {
            display: none;
        }
        .tab-content.active {
            display: block;
            animation: fadeIn 0.5s ease;
        }
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        .comment-form, .rating-form {
            display: flex;
            flex-direction: column;
            gap: 1.5rem;
        }
        .form-group {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }
        .form-group label {
            font-weight: 600;
            color: var(--dark);
        }
        .form-input, .form-textarea {
            padding: 1rem;
            border: 2px solid #ddd;
            border-radius: 8px;
            font-size: 1rem;
            transition: var(--transition);
        }
        .form-input:focus, .form-textarea:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(58,110,165,0.1);
        }
        .form-textarea {
            min-height: 150px;
            resize: vertical;
        }
        .rating-stars {
            display: flex;
            gap: 0.5rem;
            font-size: 2rem;
            color: #ffd700;
            margin: 0.5rem 0;
        }
        .star {
            cursor: pointer;
            transition: var(--transition);
        }
        .star:hover {
            transform: scale(1.2);
        }
        .submit-btn {
            background-color: var(--primary);
            color: white;
            border: none;
            padding: 1.2rem 2.5rem;
            border-radius: 8px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            align-self: flex-start;
        }
        .submit-btn:hover {
            background-color: #2d5985;
            transform: translateY(-3px);
            box-shadow: 0 7px 15px rgba(0,0,0,0.1);
        }
        .long-tail-links {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 4rem 0;
            padding: 2.5rem;
            background-color: #f0f7ff;
            border-radius: 12px;
        }
        .web-link {
            background-color: white;
            padding: 1.5rem;
            border-radius: 8px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
            transition: var(--transition);
        }
        .web-link:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 20px rgba(0,0,0,0.1);
        }
        .web-link a {
            text-decoration: none;
            color: var(--primary);
            font-weight: 600;
            display: block;
            line-height: 1.6;
        }
        .web-link a:hover {
            text-decoration: underline;
            color: #2d5985;
        }
        footer {
            background-color: var(--dark);
            color: white;
            padding: 4rem 0 2rem;
            margin-top: 4rem;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 3rem;
            margin-bottom: 3rem;
        }
        .footer-section h3 {
            color: white;
            font-size: 1.4rem;
            margin-bottom: 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--primary);
        }
        .footer-links {
            list-style: none;
        }
        .footer-links li {
            margin-bottom: 0.8rem;
        }
        .footer-links a {
            color: #c0d6df;
            text-decoration: none;
            transition: var(--transition);
        }
        .footer-links a:hover {
            color: white;
            padding-left: 5px;
        }
        .copyright {
            text-align: center;
            padding-top: 2rem;
            border-top: 1px solid #4a5c66;
            color: #a0b3bc;
            font-size: 0.95rem;
        }
        @media (max-width: 768px) {
            .desktop-nav {
                display: none;
            }
            .mobile-menu-btn {
                display: block;
            }
            .search-form {
                flex-direction: column;
            }
            .search-btn {
                padding: 1.2rem;
            }
            .interaction-tabs {
                flex-direction: column;
            }
            .tab-btn {
                text-align: left;
                border-bottom: 1px solid #eee;
            }
            .tab-btn.active::after {
                width: 5px;
                height: 100%;
                bottom: 0;
                left: 0;
                right: auto;
            }
            .long-tail-links {
                grid-template-columns: 1fr;
                padding: 1.5rem;
            }
            .footer-content {
                grid-template-columns: 1fr;
                gap: 2rem;
            }
        }
        @media (min-width: 769px) and (max-width: 992px) {
            .content-grid {
                grid-template-columns: 1fr;
            }
            sidebar {
                position: static;
                margin-top: 2rem;
            }
        }
        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }
        a:focus, button:focus, input:focus, textarea:focus {
            outline: 3px solid var(--accent);
            outline-offset: 3px;
        }
        @media print {
            .mobile-menu-btn, .search-container, .user-interaction, .long-tail-links, footer {
                display: none;
            }
        }