* { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
            line-height: 1.7;
            color: #333;
            background-color: #f8f9fa;
            max-width: 100vw;
            overflow-x: hidden;
        }
        img { max-width: 100%; height: auto; display: block; }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .text-center { text-align: center; }
        .bold { font-weight: 700; }
        .highlight { background: linear-gradient(90deg, #ffde7d, #f8a5c2); padding: 2px 6px; border-radius: 3px; }
        .emoji { font-size: 1.2em; margin-right: 5px; }
        .site-header {
            background: linear-gradient(135deg, #1a237e, #4a148c);
            color: white;
            padding: 1rem 0;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .my-logo a {
            font-size: 1.8rem;
            font-weight: 800;
            color: white;
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .my-logo i { color: #00e5ff; }
        .nav-desktop {
            display: flex;
            gap: 2rem;
        }
        @media (max-width: 768px) {
            .nav-desktop { display: none; }
        }
        .nav-desktop a {
            color: #e0e0e0;
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s;
            padding: 5px 0;
            border-bottom: 2px solid transparent;
        }
        .nav-desktop a:hover,
        .nav-desktop a.active {
            color: #00e5ff;
            border-bottom-color: #00e5ff;
        }
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
        }
        @media (max-width: 768px) {
            .hamburger { display: block; }
        }
        .nav-mobile {
            display: none;
            flex-direction: column;
            background: #2d3748;
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            padding: 1rem;
            box-shadow: 0 10px 15px rgba(0,0,0,0.2);
        }
        .nav-mobile.active { display: flex; }
        .nav-mobile a {
            color: #cbd5e0;
            padding: 0.8rem;
            text-decoration: none;
            border-bottom: 1px solid #4a5568;
        }
        .nav-mobile a:hover { background: #4a5568; color: white; }
        .breadcrumb {
            padding: 1rem 0;
            background-color: #e9ecef;
            font-size: 0.9rem;
        }
        .breadcrumb a {
            color: #6c757d;
            text-decoration: none;
        }
        .breadcrumb a:hover { text-decoration: underline; }
        .breadcrumb span { color: #495057; }
        main { padding: 2rem 0; background: white; }
        article { max-width: 900px; margin: 0 auto; padding: 0 20px; }
        h1 {
            font-size: 2.8rem;
            margin-bottom: 1.5rem;
            color: #1a237e;
            line-height: 1.2;
            border-bottom: 4px solid #ffde7d;
            padding-bottom: 0.5rem;
        }
        @media (max-width: 768px) { h1 { font-size: 2.2rem; } }
        h2 {
            font-size: 2rem;
            margin: 2.5rem 0 1rem;
            color: #4a148c;
            padding-left: 10px;
            border-left: 5px solid #00e5ff;
        }
        h3 {
            font-size: 1.6rem;
            margin: 2rem 0 0.8rem;
            color: #6a1b9a;
        }
        h4 {
            font-size: 1.3rem;
            margin: 1.5rem 0 0.6rem;
            color: #8e24aa;
        }
        p {
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
            text-align: justify;
            hyphens: auto;
        }
        .intro {
            font-size: 1.3rem;
            color: #555;
            background: #f1f8ff;
            padding: 1.5rem;
            border-radius: 10px;
            margin-bottom: 2.5rem;
            border-left: 5px solid #1a237e;
        }
        .key-point {
            background: linear-gradient(to right, #e3f2fd, #f3e5f5);
            padding: 1.5rem;
            border-radius: 8px;
            margin: 2rem 0;
            border: 1px dashed #ba68c8;
        }
        .article-img {
            margin: 2.5rem auto;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 25px rgba(0,0,0,0.15);
            max-width: 800px;
        }
        .article-img figcaption {
            text-align: center;
            font-style: italic;
            color: #666;
            padding: 0.8rem;
            background: #f9f9f9;
        }
        .interactive-box {
            background: #f8f9fa;
            border: 2px solid #dee2e6;
            border-radius: 12px;
            padding: 2rem;
            margin: 3rem 0;
        }
        .interactive-box h3 { margin-top: 0; color: #1a237e; }
        form { display: grid; gap: 1rem; }
        input, textarea, select {
            padding: 0.8rem 1rem;
            border: 1px solid #ced4da;
            border-radius: 8px;
            font-family: inherit;
            font-size: 1rem;
            transition: border 0.3s;
        }
        input:focus, textarea:focus, select:focus {
            outline: none;
            border-color: #4a148c;
            box-shadow: 0 0 0 3px rgba(74, 20, 140, 0.2);
        }
        button, .btn {
            background: linear-gradient(90deg, #6a11cb, #2575fc);
            color: white;
            border: none;
            padding: 1rem 1.8rem;
            border-radius: 8px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            text-decoration: none;
            display: inline-block;
            text-align: center;
        }
        button:hover, .btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 7px 14px rgba(106, 17, 203, 0.3);
        }
        .rating {
            display: flex;
            gap: 5px;
            margin: 1rem 0;
        }
        .star {
            font-size: 1.8rem;
            color: #ddd;
            cursor: pointer;
            transition: color 0.2s;
        }
        .star:hover,
        .star.active { color: #ffc107; }
        .content-link {
            color: #6a11cb;
            text-decoration: none;
            border-bottom: 1px dotted currentColor;
            font-weight: 500;
        }
        .content-link:hover {
            color: #2575fc;
            border-bottom-style: solid;
        }
        .site-footer {
            background: #1a202c;
            color: #cbd5e0;
            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 h4 {
            color: #fff;
            margin-bottom: 1.2rem;
            font-size: 1.2rem;
        }
        friend-link {
            display: block;
            margin-bottom: 0.8rem;
        }
        friend-link a {
            color: #90cdf4;
            text-decoration: none;
        }
        friend-link a:hover { color: #63b3ed; text-decoration: underline; }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid #2d3748;
            font-size: 0.9rem;
            color: #a0aec0;
        }
        .last-updated {
            font-size: 0.9rem;
            color: #718096;
            text-align: right;
            margin-top: 3rem;
            padding-top: 1rem;
            border-top: 1px solid #e2e8f0;
        }