* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.8;
            color: #333;
            background-color: #f9f9f9;
            max-width: 100%;
            overflow-x: hidden;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: color 0.3s;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        header {
            background: linear-gradient(135deg, #2c3e50, #4a6491);
            color: #fff;
            padding: 1rem 0;
            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;
        }
        .logo a {
            font-size: 2.2rem;
            font-weight: 800;
            letter-spacing: 1px;
            background: linear-gradient(to right, #ffcc00, #ff9900);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            display: flex;
            align-items: center;
        }
        .logo i {
            margin-right: 10px;
            font-size: 2.5rem;
            color: #ffcc00;
        }
        .logo-text {
            font-family: 'Arial Black', sans-serif;
        }
        nav ul {
            display: flex;
            list-style: none;
        }
        nav ul li {
            margin-left: 2rem;
        }
        nav ul li a {
            font-weight: 600;
            font-size: 1.1rem;
            padding: 0.5rem 1rem;
            border-radius: 5px;
        }
        nav ul li a:hover {
            background-color: rgba(255, 255, 255, 0.15);
            color: #ffcc00;
        }
        .hamburger {
            display: none;
            cursor: pointer;
            font-size: 1.8rem;
        }
        .breadcrumb {
            background-color: #e9ecef;
            padding: 1rem 0;
            font-size: 0.95rem;
        }
        .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: #666;
        }
        .breadcrumb a:hover {
            color: #2c3e50;
            text-decoration: underline;
        }
        main {
            padding: 2rem 0;
            background-color: #fff;
            box-shadow: 0 0 15px rgba(0,0,0,0.05);
            border-radius: 10px;
            margin: 2rem auto;
        }
        article {
            padding: 0 2rem;
        }
        h1, h2, h3, h4 {
            color: #2c3e50;
            margin-bottom: 1rem;
            line-height: 1.4;
        }
        h1 {
            font-size: 2.8rem;
            border-bottom: 3px solid #ffcc00;
            padding-bottom: 0.5rem;
            margin-bottom: 2rem;
        }
        h2 {
            font-size: 2.2rem;
            margin-top: 2.5rem;
            background-color: #f1f8ff;
            padding: 1rem;
            border-left: 5px solid #4a6491;
        }
        h3 {
            font-size: 1.8rem;
            margin-top: 2rem;
            color: #4a6491;
        }
        h4 {
            font-size: 1.5rem;
            margin-top: 1.5rem;
            color: #666;
        }
        p {
            margin-bottom: 1.5rem;
            text-align: justify;
            font-size: 1.15rem;
        }
        .highlight {
            background-color: #fffacd;
            padding: 1.5rem;
            border-left: 4px solid #ffcc00;
            margin: 2rem 0;
            border-radius: 0 8px 8px 0;
        }
        .tip-box {
            background-color: #e6f7ff;
            border: 1px solid #91d5ff;
            padding: 1.5rem;
            border-radius: 8px;
            margin: 2rem 0;
        }
        .tip-box i {
            color: #1890ff;
            margin-right: 10px;
        }
        .puzzle-image {
            text-align: center;
            margin: 3rem 0;
        }
        .puzzle-image img {
            border-radius: 10px;
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            border: 5px solid #fff;
            max-width: 800px;
            margin: 0 auto;
        }
        .puzzle-image figcaption {
            font-style: italic;
            margin-top: 0.5rem;
            color: #666;
        }
        .difficulty-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
        }
        .difficulty-card {
            background: #f8f9fa;
            padding: 2rem;
            border-radius: 10px;
            text-align: center;
            transition: transform 0.3s, box-shadow 0.3s;
            border-top: 5px solid #4a6491;
        }
        .difficulty-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }
        .difficulty-card i {
            font-size: 3rem;
            margin-bottom: 1rem;
            color: #4a6491;
        }
        .download-btn {
            display: inline-block;
            background: linear-gradient(to right, #28a745, #20c997);
            color: white;
            padding: 0.8rem 1.8rem;
            border-radius: 50px;
            font-weight: bold;
            margin-top: 1rem;
            transition: all 0.3s;
        }
        .download-btn:hover {
            background: linear-gradient(to right, #20c997, #28a745);
            box-shadow: 0 5px 15px rgba(32, 201, 151, 0.4);
        }
        .user-actions {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
            padding: 2rem;
            background-color: #f1f8ff;
            border-radius: 10px;
        }
        .search-box, .comment-box, .rating-box {
            background: white;
            padding: 2rem;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }
        .search-box h3, .comment-box h3, .rating-box h3 {
            margin-top: 0;
            display: flex;
            align-items: center;
        }
        .search-box h3 i, .comment-box h3 i, .rating-box h3 i {
            margin-right: 10px;
            color: #4a6491;
        }
        form input, form textarea, form select {
            width: 100%;
            padding: 1rem;
            margin-bottom: 1rem;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-size: 1rem;
            font-family: inherit;
        }
        form button {
            background: #4a6491;
            color: white;
            border: none;
            padding: 1rem 2rem;
            border-radius: 5px;
            cursor: pointer;
            font-weight: bold;
            transition: background 0.3s;
            width: 100%;
        }
        form button:hover {
            background: #2c3e50;
        }
        .stars {
            display: flex;
            justify-content: center;
            margin: 1rem 0;
        }
        .stars i {
            font-size: 2rem;
            color: #ddd;
            cursor: pointer;
            margin: 0 5px;
            transition: color 0.3s;
        }
        .stars i:hover,
        .stars i.active {
            color: #ffcc00;
        }
        .footer-links {
            background-color: #2c3e50;
            padding: 3rem 0;
            color: #ccc;
        }
        .web-link {
            display: inline-block;
            margin: 0.8rem;
            padding: 0.8rem 1.5rem;
            background-color: rgba(255,255,255,0.1);
            border-radius: 5px;
            transition: all 0.3s;
        }
        .web-link:hover {
            background-color: rgba(255,255,255,0.2);
            color: #ffcc00;
        }
        .footer-links-container {
            text-align: center;
        }
        footer {
            background-color: #1a252f;
            color: #aaa;
            text-align: center;
            padding: 2rem 0;
            font-size: 0.95rem;
        }
        .copyright a {
            color: #ffcc00;
        }
        .copyright a:hover {
            text-decoration: underline;
        }
        @media (max-width: 992px) {
            h1 { font-size: 2.4rem; }
            h2 { font-size: 2rem; }
            h3 { font-size: 1.6rem; }
            .header-container { flex-wrap: wrap; }
            nav ul { display: none; flex-direction: column; width: 100%; margin-top: 1rem; }
            nav ul.active { display: flex; }
            nav ul li { margin: 0.5rem 0; }
            .hamburger { display: block; }
        }
        @media (max-width: 768px) {
            .container { padding: 0 15px; }
            article { padding: 0 1rem; }
            h1 { font-size: 2rem; }
            h2 { font-size: 1.8rem; }
            .difficulty-grid { grid-template-columns: 1fr; }
            .user-actions { grid-template-columns: 1fr; }
            .logo a { font-size: 1.8rem; }
        }