* { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, 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; }
        h1, h2, h3, h4 { color: #1a365d; margin-bottom: 0.75rem; font-weight: 700; line-height: 1.3; }
        h1 { font-size: 2.8rem; margin-top: 1.5rem; border-bottom: 4px solid #e53e3e; padding-bottom: 0.5rem; }
        h2 { font-size: 2.2rem; margin-top: 2.5rem; padding-left: 0.5rem; border-left: 5px solid #4299e1; }
        h3 { font-size: 1.8rem; margin-top: 2rem; color: #2d3748; }
        h4 { font-size: 1.4rem; margin-top: 1.5rem; color: #4a5568; }
        p { margin-bottom: 1.5rem; text-align: justify; }
        a { color: #2b6cb0; text-decoration: none; transition: color 0.3s ease; }
        a:hover { color: #e53e3e; text-decoration: underline; }
        strong { color: #2d3748; font-weight: 700; }
        em { font-style: italic; color: #718096; }
        .container {
            width: 100%;
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 1.5rem;
        }
        main.container { padding-top: 2rem; padding-bottom: 3rem; }
        .site-header {
            background: linear-gradient(135deg, #1a365d 0%, #2d3748 100%);
            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 {
            font-size: 2.2rem;
            font-weight: 900;
            color: #fff;
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 0.75rem;
        }
        .my-logo:hover { color: #63b3ed; text-decoration: none; }
        .my-logo i { color: #e53e3e; }
        .breadcrumb {
            background-color: #edf2f7;
            padding: 0.8rem 1.5rem;
            font-size: 0.9rem;
            border-bottom: 1px solid #cbd5e0;
        }
        .breadcrumb a { color: #4a5568; }
        .breadcrumb a:hover { color: #1a365d; }
        .breadcrumb span { color: #718096; }
        .main-nav ul {
            display: flex;
            list-style: none;
            gap: 2rem;
        }
        .main-nav a {
            color: #cbd5e0;
            font-weight: 600;
            padding: 0.5rem 0;
            position: relative;
        }
        .main-nav a:hover,
        .main-nav a.active { color: white; text-decoration: none; }
        .main-nav a.active::after {
            content: '';
            position: absolute;
            bottom: -5px;
            left: 0;
            width: 100%;
            height: 3px;
            background-color: #e53e3e;
            border-radius: 2px;
        }
        .hamburger {
            display: none;
            font-size: 1.8rem;
            background: none;
            border: none;
            color: white;
            cursor: pointer;
            padding: 0.5rem;
        }
        .search-box {
            display: flex;
            max-width: 400px;
            margin: 2rem auto;
            border: 2px solid #cbd5e0;
            border-radius: 50px;
            overflow: hidden;
            background: white;
        }
        .search-box input {
            flex-grow: 1;
            padding: 0.9rem 1.5rem;
            border: none;
            outline: none;
            font-size: 1rem;
        }
        .search-box button {
            background-color: #2b6cb0;
            color: white;
            border: none;
            padding: 0 1.8rem;
            cursor: pointer;
            font-size: 1.1rem;
            transition: background 0.3s;
        }
        .search-box button:hover { background-color: #1a365d; }
        article {
            background: white;
            padding: 2.5rem;
            border-radius: 12px;
            box-shadow: 0 6px 20px rgba(0,0,0,0.08);
            margin-bottom: 2.5rem;
        }
        .article-meta {
            display: flex;
            justify-content: space-between;
            align-items: center;
            color: #718096;
            font-size: 0.95rem;
            margin-bottom: 2rem;
            padding-bottom: 1rem;
            border-bottom: 1px dashed #cbd5e0;
        }
        .last-updated i { color: #e53e3e; margin-right: 0.5rem; }
        .featured-img {
            width: 100%;
            max-height: 500px;
            object-fit: cover;
            border-radius: 10px;
            margin: 2rem 0;
            border: 1px solid #e2e8f0;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }
        .highlight-box {
            background: linear-gradient(to right, #ebf8ff, #bee3f8);
            border-left: 5px solid #3182ce;
            padding: 1.5rem;
            margin: 2rem 0;
            border-radius: 0 8px 8px 0;
        }
        .tip { background-color: #f0fff4; border-color: #38a169; }
        .warning { background-color: #fff5f5; border-color: #e53e3e; }
        .comparison-table {
            width: 100%;
            border-collapse: collapse;
            margin: 2.5rem 0;
            box-shadow: 0 4px 10px rgba(0,0,0,0.05);
        }
        .comparison-table th, .comparison-table td {
            border: 1px solid #cbd5e0;
            padding: 1rem;
            text-align: left;
        }
        .comparison-table th {
            background-color: #2d3748;
            color: white;
            font-weight: 600;
        }
        .comparison-table tr:nth-child(even) { background-color: #f7fafc; }
        .comparison-table tr:hover { background-color: #ebf8ff; }
        .user-interaction {
            background-color: #f7fafc;
            padding: 2.5rem;
            border-radius: 12px;
            margin-top: 3rem;
            border: 1px solid #e2e8f0;
        }
        .interaction-title { text-align: center; margin-bottom: 2rem; }
        .rating-form, .comment-form {
            display: grid;
            gap: 1.5rem;
            margin-bottom: 2.5rem;
        }
        .stars {
            display: flex;
            justify-content: center;
            gap: 0.5rem;
            font-size: 2rem;
            color: #cbd5e0;
            margin-bottom: 1rem;
        }
        .stars i { cursor: pointer; transition: color 0.2s, transform 0.2s; }
        .stars i:hover { transform: scale(1.2); }
        .stars i.active { color: #f6ad55; }
        .form-group { display: flex; flex-direction: column; }
        .form-group label { margin-bottom: 0.5rem; font-weight: 600; color: #4a5568; }
        .form-group input,
        .form-group textarea,
        .form-group select {
            padding: 0.9rem;
            border: 1px solid #cbd5e0;
            border-radius: 8px;
            font-size: 1rem;
            font-family: inherit;
            transition: border 0.3s;
        }
        .form-group input:focus,
        .form-group textarea:focus,
        .form-group select:focus {
            outline: none;
            border-color: #4299e1;
            box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.15);
        }
        .submit-btn {
            background: linear-gradient(to right, #2b6cb0, #1a365d);
            color: white;
            border: none;
            padding: 1rem 2rem;
            border-radius: 8px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: transform 0.3s, box-shadow 0.3s;
            justify-self: start;
        }
        .submit-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 6px 12px rgba(43, 108, 176, 0.3);
        }
        .site-footer {
            background-color: #1a202c;
            color: #a0aec0;
            padding: 3rem 0 1.5rem;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2.5rem;
            margin-bottom: 2.5rem;
        }
        .footer-section h4 {
            color: #e2e8f0;
            margin-bottom: 1.2rem;
            font-size: 1.3rem;
        }
        .footer-links { list-style: none; }
        .footer-links li { margin-bottom: 0.8rem; }
        .footer-links a { color: #a0aec0; }
        .footer-links a:hover { color: #63b3ed; }
        friend-link {
            display: block;
            padding: 1rem;
            background-color: #2d3748;
            border-radius: 8px;
            margin-bottom: 1rem;
            transition: background 0.3s;
        }
        friend-link:hover { background-color: #4a5568; }
        friend-link a { color: #90cdf4; font-weight: 600; }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid #2d3748;
            font-size: 0.9rem;
            color: #718096;
        }
        @media (max-width: 992px) {
            h1 { font-size: 2.4rem; }
            h2 { font-size: 2rem; }
            h3 { font-size: 1.6rem; }
            .header-content { flex-direction: column; align-items: flex-start; gap: 1rem; }
            .main-nav { width: 100%; }
            .main-nav ul { flex-direction: column; gap: 0; display: none; }
            .main-nav.active ul {
                display: flex;
                background-color: #2d3748;
                padding: 1rem 0;
                border-radius: 8px;
                margin-top: 1rem;
            }
            .main-nav a { display: block; padding: 0.8rem 1.5rem; }
            .hamburger { display: block; }
            .search-box { max-width: 100%; }
            article { padding: 1.8rem; }
        }
        @media (max-width: 768px) {
            .container { padding: 0 1rem; }
            h1 { font-size: 2rem; }
            h2 { font-size: 1.8rem; }
            .article-meta { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
            .footer-content { grid-template-columns: 1fr; }
            .comparison-table { display: block; overflow-x: auto; }
        }