* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        :root {
            --primary-color: #3a7bd5;
            --secondary-color: #00d2ff;
            --accent-color: #ff6b6b;
            --dark-color: #2c3e50;
            --light-color: #f8f9fa;
            --text-color: #333;
            --text-light: #666;
            --border-color: #e1e5eb;
            --shadow: 0 4px 12px rgba(0,0,0,0.1);
            --transition: all 0.3s ease;
            --border-radius: 8px;
            --max-width: 1200px;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
        }
        header {
            background: linear-gradient(to right, var(--dark-color), var(--primary-color));
            color: white;
            padding: 1rem 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: var(--shadow);
        }
        .header-container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 2rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .my-logo {
            font-family: 'Arial Rounded MT Bold', sans-serif;
            font-size: 2.2rem;
            font-weight: 900;
            color: white;
            text-decoration: none;
            letter-spacing: 2px;
            display: flex;
            align-items: center;
            gap: 10px;
            transition: var(--transition);
        }
        .my-logo:hover {
            transform: scale(1.05);
            color: var(--secondary-color);
        }
        .logo-letters {
            display: inline-flex;
            gap: 3px;
        }
        .logo-letters span {
            display: inline-block;
            width: 40px;
            height: 40px;
            background: white;
            color: var(--primary-color);
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 900;
            border-radius: 6px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.2);
        }
        nav {
            display: flex;
            align-items: center;
        }
        .nav-links {
            display: flex;
            list-style: none;
            gap: 1.8rem;
        }
        .nav-links a {
            color: white;
            text-decoration: none;
            font-weight: 600;
            font-size: 1.05rem;
            padding: 0.5rem 0;
            position: relative;
            transition: var(--transition);
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background: var(--secondary-color);
            transition: var(--transition);
        }
        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }
        .nav-links a:hover {
            color: var(--secondary-color);
        }
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
            padding: 0.5rem;
        }
        .breadcrumb {
            max-width: var(--max-width);
            margin: 1.5rem auto;
            padding: 0 2rem;
            font-size: 0.9rem;
        }
        .breadcrumb a {
            color: var(--primary-color);
            text-decoration: none;
        }
        .breadcrumb a:hover {
            text-decoration: underline;
        }
        .main-container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 2rem 3rem;
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 2.5rem;
        }
        article {
            background: white;
            border-radius: var(--border-radius);
            padding: 2.5rem;
            box-shadow: var(--shadow);
            margin-bottom: 2rem;
        }
        h1 {
            font-size: 2.8rem;
            color: var(--dark-color);
            margin-bottom: 1.5rem;
            line-height: 1.2;
            background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        h2 {
            font-size: 2rem;
            color: var(--dark-color);
            margin: 2.5rem 0 1.2rem;
            padding-bottom: 0.5rem;
            border-bottom: 3px solid var(--border-color);
        }
        h3 {
            font-size: 1.6rem;
            color: var(--primary-color);
            margin: 2rem 0 1rem;
        }
        h4 {
            font-size: 1.3rem;
            color: var(--text-color);
            margin: 1.5rem 0 0.8rem;
        }
        p {
            margin-bottom: 1.2rem;
            font-size: 1.08rem;
        }
        .lead {
            font-size: 1.3rem;
            font-weight: 500;
            color: var(--dark-color);
            line-height: 1.5;
            margin-bottom: 2rem;
            padding: 1.5rem;
            background: linear-gradient(90deg, #f8f9fa 0%, #e9ecef 100%);
            border-left: 5px solid var(--primary-color);
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
        }
        .highlight {
            background: linear-gradient(120deg, #a1c4fd 0%, #c2e9fb 100%);
            padding: 1.5rem;
            border-radius: var(--border-radius);
            margin: 2rem 0;
            border-left: 5px solid var(--primary-color);
        }
        .content-img {
            width: 100%;
            max-width: 800px;
            height: auto;
            border-radius: var(--border-radius);
            margin: 2rem auto;
            display: block;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        .content-img:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 20px rgba(0,0,0,0.15);
        }
        .img-caption {
            text-align: center;
            font-style: italic;
            color: var(--text-light);
            margin-top: 0.5rem;
            font-size: 0.95rem;
        }
        .feature-card {
            background: white;
            border-radius: var(--border-radius);
            padding: 2rem;
            margin: 2.5rem 0;
            box-shadow: var(--shadow);
            border-top: 5px solid var(--accent-color);
        }
        .feature-card h3 {
            margin-top: 0;
        }
        form {
            display: flex;
            flex-direction: column;
            gap: 1.2rem;
            margin-top: 1.5rem;
        }
        .form-group {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }
        label {
            font-weight: 600;
            color: var(--dark-color);
        }
        input, textarea, select {
            padding: 0.9rem 1.2rem;
            border: 2px solid var(--border-color);
            border-radius: var(--border-radius);
            font-family: inherit;
            font-size: 1rem;
            transition: var(--transition);
        }
        input:focus, textarea:focus, select:focus {
            outline: none;
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(58, 123, 213, 0.2);
        }
        button, .btn {
            background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
            color: white;
            border: none;
            padding: 1rem 2rem;
            border-radius: var(--border-radius);
            font-weight: 700;
            font-size: 1.05rem;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
            text-decoration: none;
            display: inline-block;
        }
        button:hover, .btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 6px 15px rgba(58, 123, 213, 0.3);
        }
        .rating {
            display: flex;
            gap: 0.5rem;
            margin: 1rem 0;
        }
        .star {
            font-size: 1.8rem;
            color: #ddd;
            cursor: pointer;
            transition: var(--transition);
        }
        .star:hover,
        .star.active {
            color: #ffc107;
        }
        sidebar {
            background: white;
            border-radius: var(--border-radius);
            padding: 2rem;
            box-shadow: var(--shadow);
            height: fit-content;
            position: sticky;
            top: 120px;
        }
        .sidebar-widget {
            margin-bottom: 2.5rem;
        }
        .sidebar-widget h3 {
            font-size: 1.4rem;
            margin-bottom: 1.2rem;
            color: var(--dark-color);
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--border-color);
        }
        .related-links {
            list-style: none;
        }
        .related-links li {
            margin-bottom: 1rem;
            padding-bottom: 1rem;
            border-bottom: 1px solid var(--border-color);
        }
        .related-links a {
            color: var(--text-color);
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 10px;
            transition: var(--transition);
        }
        .related-links a:hover {
            color: var(--primary-color);
            transform: translateX(5px);
        }
        .related-links i {
            color: var(--primary-color);
        }
        footer {
            background: var(--dark-color);
            color: white;
            padding: 3rem 0 2rem;
            margin-top: 3rem;
        }
        .footer-container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 2rem;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 3rem;
        }
        .footer-section h3 {
            color: white;
            margin-bottom: 1.5rem;
            font-size: 1.4rem;
        }
        friend-link {
            display: block;
            margin-bottom: 0.8rem;
        }
        friend-link a {
            color: #a0c3ff;
            text-decoration: none;
            transition: var(--transition);
        }
        friend-link a:hover {
            color: white;
            text-decoration: underline;
        }
        .copyright {
            text-align: center;
            padding-top: 2rem;
            margin-top: 2rem;
            border-top: 1px solid rgba(255,255,255,0.1);
            color: #aaa;
            font-size: 0.95rem;
        }
        @media (max-width: 992px) {
            .main-container {
                grid-template-columns: 1fr;
            }
            sidebar {
                position: static;
                margin-top: 2rem;
            }
            h1 {
                font-size: 2.4rem;
            }
            h2 {
                font-size: 1.8rem;
            }
        }
        @media (max-width: 768px) {
            .header-container {
                padding: 0 1.5rem;
            }
            .hamburger {
                display: block;
            }
            .nav-links {
                position: fixed;
                top: 80px;
                left: 0;
                width: 100%;
                background: var(--dark-color);
                flex-direction: column;
                padding: 2rem;
                gap: 0;
                transform: translateY(-100%);
                opacity: 0;
                transition: var(--transition);
                pointer-events: none;
                box-shadow: var(--shadow);
                z-index: 999;
            }
            .nav-links.active {
                transform: translateY(0);
                opacity: 1;
                pointer-events: all;
            }
            .nav-links li {
                width: 100%;
                margin-bottom: 0.5rem;
            }
            .nav-links a {
                display: block;
                padding: 1rem;
                border-radius: var(--border-radius);
                background: rgba(255,255,255,0.05);
            }
            .main-container, .breadcrumb, .footer-container {
                padding-left: 1.5rem;
                padding-right: 1.5rem;
            }
            article {
                padding: 1.8rem;
            }
            h1 {
                font-size: 2rem;
            }
            h2 {
                font-size: 1.6rem;
            }
        }
        @media (max-width: 480px) {
            .my-logo {
                font-size: 1.8rem;
            }
            .logo-letters span {
                width: 32px;
                height: 32px;
                font-size: 0.9rem;
            }
            article {
                padding: 1.5rem;
            }
            .lead {
                font-size: 1.1rem;
                padding: 1.2rem;
            }
            .feature-card {
                padding: 1.5rem;
            }
        }
        .term {
            background: #e8f4fc;
            padding: 0.2rem 0.5rem;
            border-radius: 4px;
            font-weight: 600;
            color: var(--primary-color);
        }
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
            margin: 2rem 0;
        }
        .stat-card {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 1.5rem;
            border-radius: var(--border-radius);
            text-align: center;
        }
        .stat-number {
            font-size: 2.5rem;
            font-weight: 900;
            margin-bottom: 0.5rem;
        }
        .stat-label {
            font-size: 1rem;
            opacity: 0.9;
        }
        .quote {
            font-style: italic;
            font-size: 1.2rem;
            color: var(--dark-color);
            padding: 2rem;
            margin: 2rem 0;
            background: #f8f9fa;
            border-left: 5px solid var(--accent-color);
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
        }
        .quote-author {
            text-align: right;
            font-weight: 600;
            margin-top: 1rem;
            color: var(--text-light);
        }
        .tooltip {
            position: relative;
            display: inline-block;
            border-bottom: 1px dotted var(--primary-color);
            cursor: help;
        }
        .tooltip .tooltiptext {
            visibility: hidden;
            width: 200px;
            background-color: var(--dark-color);
            color: white;
            text-align: center;
            border-radius: var(--border-radius);
            padding: 0.8rem;
            position: absolute;
            z-index: 1;
            bottom: 125%;
            left: 50%;
            transform: translateX(-50%);
            opacity: 0;
            transition: opacity 0.3s;
            font-size: 0.9rem;
            font-weight: normal;
        }
        .tooltip:hover .tooltiptext {
            visibility: visible;
            opacity: 1;
        }
        .emoji {
            font-size: 1.2em;
            margin: 0 0.2rem;
        }
        .content-link {
            color: var(--primary-color);
            text-decoration: none;
            font-weight: 600;
            transition: var(--transition);
        }
        .content-link:hover {
            color: var(--secondary-color);
            text-decoration: underline;
        }