* { 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: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }
        a { color: #2c5282; text-decoration: none; transition: color 0.3s ease, transform 0.2s ease; }
        a:hover { color: #1a365d; transform: translateY(-1px); }
        img { max-width: 100%; height: auto; display: block; }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }
        .site-header {
            background: linear-gradient(90deg, #1a237e 0%, #283593 50%, #3949ab 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: 2rem;
            font-weight: 800;
            background: linear-gradient(to right, #4fc3f7, #00e5ff);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 0 2px 4px rgba(0,0,0,0.2);
            letter-spacing: -0.5px;
        }
        .my-logo:hover { transform: scale(1.03); }
        .nav-desktop { display: flex; gap: 1.5rem; }
        .nav-desktop a { color: #bbdefb; font-weight: 600; padding: 0.5rem 0; }
        .nav-desktop a:hover { color: white; border-bottom: 2px solid #00e5ff; }
        .hamburger-btn {
            display: none;
            background: none;
            border: none;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
            padding: 0.5rem;
        }
        .nav-mobile {
            display: none;
            flex-direction: column;
            background: #283593;
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            padding: 1rem;
            box-shadow: 0 6px 12px rgba(0,0,0,0.15);
        }
        .nav-mobile.active { display: flex; }
        .nav-mobile a { color: #e3f2fd; padding: 0.8rem; border-bottom: 1px solid #3949ab; }
        .nav-mobile a:last-child { border-bottom: none; }
        .nav-mobile a:hover { background: #3949ab; }
        .breadcrumb {
            padding: 1rem 0;
            background: #e8eaf6;
            font-size: 0.9rem;
        }
        .breadcrumb a { color: #5c6bc0; }
        .breadcrumb span { color: #78909c; }
        main { flex: 1; padding: 2rem 0; }
        article {
            background: white;
            border-radius: 16px;
            padding: 2.5rem;
            box-shadow: 0 8px 30px rgba(0, 0, 50, 0.08);
            margin-bottom: 2rem;
        }
        h1 {
            font-size: 2.8rem;
            color: #1a237e;
            margin-bottom: 1.5rem;
            line-height: 1.2;
            border-bottom: 3px solid #00e5ff;
            padding-bottom: 0.5rem;
        }
        h2 {
            font-size: 2rem;
            color: #283593;
            margin: 2.5rem 0 1rem;
            padding-left: 0.5rem;
            border-left: 5px solid #ff9800;
        }
        h3 {
            font-size: 1.6rem;
            color: #3949ab;
            margin: 2rem 0 0.8rem;
        }
        h4 {
            font-size: 1.3rem;
            color: #5c6bc0;
            margin: 1.5rem 0 0.6rem;
        }
        p {
            margin-bottom: 1.5rem;
            text-align: justify;
            font-size: 1.1rem;
        }
        .intro { font-size: 1.2rem; color: #555; font-weight: 500; background: #f3f8ff; padding: 1.5rem; border-radius: 10px; margin-bottom: 2rem; }
        .highlight { background: linear-gradient(120deg, #e1f5fe 0%, #f3e5f5 100%); padding: 2rem; border-radius: 12px; margin: 2rem 0; border-left: 6px solid #7b1fa2; }
        .key-point { font-weight: bold; color: #d81b60; }
        blockquote {
            font-style: italic;
            color: #546e7a;
            border-left: 4px solid #4db6ac;
            padding-left: 1.5rem;
            margin: 2rem 0;
        }
        .content-img {
            width: 80%;
            margin: 2rem auto;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 6px 20px rgba(0,0,0,0.1);
            border: 5px solid white;
        }
        .img-caption { text-align: center; font-style: italic; color: #666; margin-top: 0.5rem; font-size: 0.95rem; }
        ul, ol { margin: 1rem 0 1rem 2rem; }
        li { margin-bottom: 0.5rem; }
        .interactive-section {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
        }
        .feature-box {
            background: #f8fdff;
            border: 2px solid #bbdefb;
            border-radius: 12px;
            padding: 2rem;
            text-align: center;
            transition: all 0.3s ease;
        }
        .feature-box:hover {
            transform: translateY(-8px);
            box-shadow: 0 12px 24px rgba(30, 136, 229, 0.15);
            border-color: #2196f3;
        }
        .feature-box i { font-size: 2.5rem; color: #2196f3; margin-bottom: 1rem; }
        .feature-box h3 { color: #1565c0; margin-bottom: 0.8rem; }
        form { display: flex; flex-direction: column; gap: 1rem; }
        input, textarea, select {
            padding: 0.8rem;
            border: 1px solid #90a4ae;
            border-radius: 8px;
            font-family: inherit;
            font-size: 1rem;
            transition: border 0.3s;
        }
        input:focus, textarea:focus, select:focus { outline: none; border-color: #2196f3; box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.2); }
        button {
            background: linear-gradient(90deg, #2196f3, #0d47a1);
            color: white;
            border: none;
            padding: 1rem 1.5rem;
            border-radius: 8px;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s;
        }
        button:hover { background: linear-gradient(90deg, #0d47a1, #1565c0); transform: scale(1.03); }
        .stars { display: flex; justify-content: center; gap: 0.5rem; margin: 1rem 0; }
        .star { font-size: 1.8rem; color: #ddd; cursor: pointer; transition: color 0.2s; }
        .star.active, .star:hover { color: #ffc107; }
        .link-cloud {
            background: #e8f5e9;
            padding: 1.5rem;
            border-radius: 10px;
            margin: 2rem 0;
            display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center;
        }
        .link-cloud a {
            background: white;
            padding: 0.5rem 1rem;
            border-radius: 50px;
            border: 1px solid #81c784;
            font-weight: 600;
            color: #2e7d32;
        }
        .link-cloud a:hover { background: #c8e6c9; transform: translateY(-3px); }
        footer {
            background: #1a237e;
            color: #e8eaf6;
            padding: 3rem 0 1.5rem;
            margin-top: auto;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin-bottom: 2rem;
        }
        .footer-section h3 { color: #bbdefb; margin-bottom: 1rem; font-size: 1.3rem; }
        .footer-links { list-style: none; margin: 0; }
        .footer-links li { margin-bottom: 0.7rem; }
        .footer-links a { color: #c5cae9; }
        .footer-links a:hover { color: #00e5ff; }
        friend-link {
            display: block;
            background: #283593;
            padding: 1.5rem;
            border-radius: 8px;
            margin: 1rem 0;
            text-align: center;
            font-weight: bold;
            color: #bbdefb;
            border: 2px dashed #5c6bc0;
        }
        friend-link a { color: #00e5ff; font-size: 1.1rem; }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid #3949ab;
            font-size: 0.9rem;
            color: #9fa8da;
        }
        @media (max-width: 768px) {
            .header-content { flex-wrap: wrap; }
            .nav-desktop { display: none; }
            .hamburger-btn { display: block; }
            h1 { font-size: 2.2rem; }
            h2 { font-size: 1.8rem; }
            h3 { font-size: 1.4rem; }
            article { padding: 1.5rem; }
            .content-img { width: 100%; }
            .interactive-section { grid-template-columns: 1fr; }
        }
        @media (max-width: 480px) {
            .container { padding: 0 15px; }
            h1 { font-size: 1.9rem; }
            .feature-box { padding: 1.5rem; }
        }