:root {
            --primary: #2c3e50;
            --secondary: #e67e22;
            --accent: #16a085;
            --light: #ecf0f1;
            --dark: #2c3e50;
            --text: #333;
            --text-light: #7f8c8d;
            --shadow: 0 4px 12px rgba(0,0,0,0.08);
            --border-radius: 10px;
            --transition: all 0.3s ease;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            line-height: 1.7;
            color: var(--text);
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
        }
        .container {
            width: 100%;
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 20px;
        }
        header {
            background-color: var(--primary);
            color: white;
            padding: 1rem 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: var(--shadow);
        }
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .logo a {
            color: white;
            text-decoration: none;
            font-size: 2.2rem;
            font-weight: 800;
            letter-spacing: -1px;
            display: flex;
            align-items: center;
        }
        .logo span {
            color: var(--secondary);
        }
        .logo i {
            margin-right: 10px;
            font-size: 2rem;
        }
        .breadcrumb {
            background-color: #34495e;
            padding: 0.8rem 0;
            font-size: 0.9rem;
            margin-bottom: 2rem;
        }
        .breadcrumb ol {
            display: flex;
            list-style: none;
            flex-wrap: wrap;
        }
        .breadcrumb li {
            margin-right: 0.5rem;
        }
        .breadcrumb li:not(:last-child)::after {
            content: '›';
            margin-left: 0.5rem;
            color: var(--light);
        }
        .breadcrumb a {
            color: var(--light);
            text-decoration: none;
            transition: var(--transition);
        }
        .breadcrumb a:hover {
            color: var(--secondary);
            text-decoration: underline;
        }
        .main-nav ul {
            display: flex;
            list-style: none;
        }
        .main-nav li {
            margin-left: 2rem;
        }
        .main-nav a {
            color: white;
            text-decoration: none;
            font-weight: 600;
            font-size: 1.1rem;
            padding: 0.5rem 0;
            position: relative;
            transition: var(--transition);
        }
        .main-nav a:hover,
        .main-nav a.active {
            color: var(--secondary);
        }
        .main-nav a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background-color: var(--secondary);
            transition: width 0.3s ease;
        }
        .main-nav a:hover::after {
            width: 100%;
        }
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
        }
        .search-container {
            margin: 2rem auto;
            max-width: 600px;
            padding: 0 1rem;
        }
        .search-form {
            display: flex;
            box-shadow: var(--shadow);
            border-radius: 50px;
            overflow: hidden;
        }
        .search-form input {
            flex-grow: 1;
            padding: 1rem 1.5rem;
            border: none;
            font-size: 1.1rem;
        }
        .search-form input:focus {
            outline: 2px solid var(--accent);
            outline-offset: -2px;
        }
        .search-form button {
            background-color: var(--accent);
            color: white;
            border: none;
            padding: 0 2rem;
            cursor: pointer;
            font-size: 1.2rem;
            transition: var(--transition);
        }
        .search-form button:hover {
            background-color: #138a72;
        }
        main {
            padding: 2rem 0;
        }
        article {
            background-color: white;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            padding: 3rem;
            margin-bottom: 2rem;
        }
        .article-header {
            text-align: center;
            margin-bottom: 3rem;
            padding-bottom: 2rem;
            border-bottom: 2px dashed var(--accent);
        }
        .article-header h1 {
            font-size: 2.8rem;
            color: var(--primary);
            margin-bottom: 1rem;
            line-height: 1.2;
        }
        .article-header .meta {
            color: var(--text-light);
            font-style: italic;
            font-size: 1.1rem;
        }
        .content-section {
            margin-bottom: 3rem;
        }
        h2 {
            font-size: 2.2rem;
            color: var(--primary);
            margin: 2.5rem 0 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--secondary);
        }
        h3 {
            font-size: 1.8rem;
            color: var(--dark);
            margin: 2rem 0 1rem;
        }
        h4 {
            font-size: 1.4rem;
            color: #555;
            margin: 1.5rem 0 1rem;
        }
        p {
            margin-bottom: 1.5rem;
            font-size: 1.15rem;
            text-align: justify;
        }
        .lead {
            font-size: 1.4rem;
            color: var(--primary);
            font-weight: 600;
            line-height: 1.8;
            padding: 1.5rem;
            background-color: #f8f9fa;
            border-left: 5px solid var(--accent);
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
            margin: 2rem 0;
        }
        .highlight {
            background-color: #fff9e6;
            padding: 2rem;
            border-radius: var(--border-radius);
            border-left: 5px solid var(--secondary);
            margin: 2rem 0;
        }
        .highlight strong {
            color: var(--secondary);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
            margin: 2rem auto;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
        }
        .float-left {
            float: left;
            margin: 1rem 2rem 1rem 0;
            max-width: 50%;
        }
        .float-right {
            float: right;
            margin: 1rem 0 1rem 2rem;
            max-width: 50%;
        }
        .clearfix::after {
            content: "";
            clear: both;
            display: table;
        }
        ul, ol {
            margin-left: 2rem;
            margin-bottom: 1.5rem;
        }
        li {
            margin-bottom: 0.8rem;
        }
        .user-interaction {
            background-color: #f8f9fa;
            border-radius: var(--border-radius);
            padding: 2rem;
            margin: 3rem 0;
            border-top: 5px solid var(--accent);
        }
        .interaction-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
        }
        .interaction-box {
            background-color: white;
            padding: 2rem;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        .interaction-box:hover {
            transform: translateY(-10px);
            box-shadow: 0 12px 20px rgba(0,0,0,0.12);
        }
        .interaction-box h3 {
            color: var(--accent);
            margin-top: 0;
            display: flex;
            align-items: center;
        }
        .interaction-box h3 i {
            margin-right: 10px;
        }
        .rating-stars {
            color: #f1c40f;
            font-size: 1.8rem;
            margin: 1rem 0;
            cursor: pointer;
        }
        .rating-stars span {
            margin-right: 5px;
            transition: var(--transition);
        }
        .rating-stars span:hover {
            transform: scale(1.2);
        }
        .rating-stars span:hover ~ span {
            color: #ddd;
        }
        form {
            margin-top: 1.5rem;
        }
        .form-group {
            margin-bottom: 1.5rem;
        }
        label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
        }
        input, textarea, select {
            width: 100%;
            padding: 0.8rem 1rem;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-size: 1rem;
            transition: var(--transition);
        }
        input:focus, textarea:focus, select:focus {
            border-color: var(--accent);
            outline: none;
            box-shadow: 0 0 0 3px rgba(22, 160, 133, 0.2);
        }
        button[type="submit"] {
            background-color: var(--secondary);
            color: white;
            border: none;
            padding: 1rem 2.5rem;
            border-radius: 50px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
        }
        button[type="submit"]:hover {
            background-color: #d35400;
            transform: translateY(-3px);
            box-shadow: 0 7px 14px rgba(230, 126, 34, 0.3);
        }
        button[type="submit"] i {
            margin-right: 10px;
        }
        .long-tail-links {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 3rem 0;
        }
        .web-link {
            background-color: white;
            padding: 1.5rem;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        .web-link:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 18px rgba(0,0,0,0.12);
        }
        .web-link a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 600;
            font-size: 1.1rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            transition: var(--transition);
        }
        .web-link a:hover {
            color: var(--accent);
        }
        .web-link a i {
            color: var(--accent);
            opacity: 0;
            transform: translateX(-10px);
            transition: var(--transition);
        }
        .web-link:hover a i {
            opacity: 1;
            transform: translateX(0);
        }
        footer {
            background-color: var(--primary);
            color: var(--light);
            padding: 3rem 0 1.5rem;
            margin-top: 3rem;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin-bottom: 2rem;
        }
        .footer-section h3 {
            color: white;
            font-size: 1.5rem;
            margin-bottom: 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--accent);
            display: inline-block;
        }
        .footer-links {
            list-style: none;
        }
        .footer-links li {
            margin-bottom: 0.8rem;
        }
        .footer-links a {
            color: #bdc3c7;
            text-decoration: none;
            transition: var(--transition);
            display: inline-block;
        }
        .footer-links a:hover {
            color: var(--secondary);
            transform: translateX(5px);
        }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid #34495e;
            color: #95a5a6;
            font-size: 0.95rem;
        }
        @media (max-width: 992px) {
            .article-header h1 {
                font-size: 2.4rem;
            }
            h2 {
                font-size: 2rem;
            }
            .float-left,
            .float-right {
                float: none;
                margin: 1.5rem auto;
                max-width: 100%;
            }
        }
        @media (max-width: 768px) {
            .hamburger {
                display: block;
            }
            .main-nav {
                position: fixed;
                top: 80px;
                left: -100%;
                width: 100%;
                background-color: var(--primary);
                transition: var(--transition);
                padding: 2rem;
                box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            }
            .main-nav.active {
                left: 0;
            }
            .main-nav ul {
                flex-direction: column;
            }
            .main-nav li {
                margin: 1rem 0;
            }
            .article-header h1 {
                font-size: 2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            article {
                padding: 2rem;
            }
            .interaction-grid {
                grid-template-columns: 1fr;
            }
        }
        @media (max-width: 576px) {
            .article-header h1 {
                font-size: 1.8rem;
            }
            h2 {
                font-size: 1.6rem;
            }
            .search-form {
                flex-direction: column;
                border-radius: var(--border-radius);
            }
            .search-form input,
            .search-form button {
                width: 100%;
                border-radius: 0;
            }
            .search-form input {
                border-radius: var(--border-radius) var(--border-radius) 0 0;
            }
            .search-form button {
                border-radius: 0 0 var(--border-radius) var(--border-radius);
            }
        }