* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            background-color: #f5f7fa;
            color: #333;
            line-height: 1.7;
            max-width: 100vw;
            overflow-x: hidden;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: color 0.3s ease;
        }
        ul, ol {
            list-style-position: inside;
            margin-left: 1.5rem;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .text-center { text-align: center; }
        .bold { font-weight: 700; }
        .italic { font-style: italic; }
        .highlight {
            background-color: #fffacd;
            padding: 0 4px;
            border-radius: 3px;
        }
        .py-1 { padding-top: 1rem; padding-bottom: 1rem; }
        .py-2 { padding-top: 2rem; padding-bottom: 2rem; }
        .my-2 { margin-top: 2rem; margin-bottom: 2rem; }
        :root {
            --primary: #2c3e50; 
            --secondary: #e74c3c; 
            --accent: #3498db; 
            --light: #ecf0f1;
            --dark: #1a2530;
            --success: #27ae60;
        }
        .site-header {
            background-color: var(--primary);
            color: white;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 20px;
        }
        .logo a {
            font-size: 1.8rem;
            font-weight: 900;
            letter-spacing: 1px;
            color: white;
            display: flex;
            align-items: center;
        }
        .logo i {
            color: var(--secondary);
            margin-right: 10px;
        }
        .main-nav ul {
            display: flex;
            gap: 2rem;
        }
        .main-nav a {
            font-weight: 600;
            padding: 0.5rem 0;
            position: relative;
        }
        .main-nav a:hover {
            color: var(--accent);
        }
        .main-nav a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: var(--accent);
            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;
        }
        @media (max-width: 768px) {
            .hamburger { display: block; }
            .main-nav {
                position: fixed;
                top: 70px;
                left: -100%;
                width: 80%;
                height: calc(100vh - 70px);
                background-color: var(--dark);
                transition: left 0.4s ease;
                padding: 2rem;
                box-shadow: 4px 0 12px rgba(0,0,0,0.2);
                overflow-y: auto;
            }
            .main-nav.active {
                left: 0;
            }
            .main-nav ul {
                flex-direction: column;
                gap: 1.5rem;
            }
            .main-nav a {
                display: block;
                font-size: 1.2rem;
                border-bottom: 1px solid rgba(255,255,255,0.1);
                padding-bottom: 1rem;
            }
            .main-nav a::after {
                display: none;
            }
        }
        .breadcrumb {
            background-color: var(--light);
            padding: 0.8rem 20px;
            font-size: 0.9rem;
            border-bottom: 1px solid #ddd;
        }
        .breadcrumb a {
            color: var(--accent);
        }
        .breadcrumb a:hover {
            text-decoration: underline;
        }
        .breadcrumb span {
            color: #7f8c8d;
        }
        main {
            padding: 2rem 0;
            background-color: white;
            box-shadow: 0 0 20px rgba(0,0,0,0.05);
            border-radius: 8px;
            margin: 2rem auto;
        }
        .content-container {
            padding: 0 20px;
        }
        h1 {
            font-size: 2.8rem;
            color: var(--primary);
            margin-bottom: 1.5rem;
            line-height: 1.2;
        }
        h2 {
            font-size: 2.2rem;
            color: var(--secondary);
            margin-top: 3rem;
            margin-bottom: 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--light);
        }
        h3 {
            font-size: 1.8rem;
            color: var(--primary);
            margin-top: 2.5rem;
            margin-bottom: 1rem;
        }
        h4 {
            font-size: 1.4rem;
            color: var(--dark);
            margin-top: 2rem;
            margin-bottom: 0.8rem;
        }
        p {
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
        }
        .lead {
            font-size: 1.3rem;
            color: var(--dark);
            font-weight: 500;
            margin-bottom: 2rem;
        }
        .article-meta {
            color: #7f8c8d;
            font-size: 0.95rem;
            margin-bottom: 2rem;
            display: flex;
            gap: 1rem;
            flex-wrap: wrap;
        }
        .featured-image {
            margin: 2.5rem 0;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 8px 20px rgba(0,0,0,0.15);
        }
        .img-caption {
            text-align: center;
            font-style: italic;
            color: #666;
            margin-top: 0.5rem;
            font-size: 0.95rem;
        }
        .user-interaction {
            background-color: var(--light);
            padding: 2rem;
            border-radius: 10px;
            margin: 3rem 0;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
        }
        .interaction-box h3 {
            margin-top: 0;
            color: var(--secondary);
        }
        .form-group {
            margin-bottom: 1.2rem;
        }
        label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
        }
        input, textarea, select {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #bdc3c7;
            border-radius: 6px;
            font-size: 1rem;
            transition: border 0.3s ease;
        }
        input:focus, textarea:focus, select:focus {
            outline: none;
            border-color: var(--accent);
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
        }
        button, .btn {
            background-color: var(--accent);
            color: white;
            border: none;
            padding: 0.9rem 1.8rem;
            border-radius: 6px;
            font-weight: 600;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s;
            display: inline-block;
        }
        button:hover, .btn:hover {
            background-color: #2980b9;
            transform: translateY(-2px);
        }
        .stars {
            display: flex;
            gap: 0.5rem;
            margin: 1rem 0;
        }
        .star {
            font-size: 1.8rem;
            color: #ddd;
            cursor: pointer;
            transition: color 0.2s;
        }
        .star:hover,
        .star.active {
            color: #f39c12;
        }
        .content-links {
            background-color: #f9f9f9;
            border-left: 4px solid var(--accent);
            padding: 1.5rem;
            margin: 2rem 0;
        }
        .content-links h4 {
            margin-top: 0;
            color: var(--accent);
        }
        .content-links ul {
            list-style-type: none;
            margin-left: 0;
        }
        .content-links li {
            margin-bottom: 0.8rem;
            padding-left: 1.5rem;
            position: relative;
        }
        .content-links li::before {
            content: '🔗';
            position: absolute;
            left: 0;
        }
        .content-links a {
            color: var(--primary);
            text-decoration: underline;
            text-underline-offset: 3px;
        }
        .content-links a:hover {
            color: var(--secondary);
        }
        .site-footer {
            background-color: var(--dark);
            color: var(--light);
            padding: 3rem 0 1.5rem;
            margin-top: 4rem;
        }
        .footer-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin-bottom: 2rem;
        }
        .footer-section h4 {
            color: white;
            margin-bottom: 1.5rem;
            font-size: 1.3rem;
        }
        .footer-links a {
            display: block;
            margin-bottom: 0.8rem;
            color: #bdc3c7;
        }
        .footer-links a:hover {
            color: white;
            padding-left: 5px;
        }
        friend-link {
            display: block;
            margin-bottom: 0.8rem;
        }
        friend-link a {
            color: #bdc3c7;
        }
        friend-link a:hover {
            color: white;
        }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid rgba(255,255,255,0.1);
            color: #95a5a6;
            font-size: 0.9rem;
        }
        @media (max-width: 768px) {
            h1 { font-size: 2.2rem; }
            h2 { font-size: 1.9rem; }
            h3 { font-size: 1.6rem; }
            .user-interaction {
                grid-template-columns: 1fr;
            }
            .header-container {
                padding: 1rem;
            }
            .content-container {
                padding: 0 1rem;
            }
        }