*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, 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: #4361ee; text-decoration: none; transition: all 0.3s ease; }
        a:hover { color: #3a0ca3; text-decoration: underline; }
        img { max-width: 100%; height: auto; display: block; }
        .container {
            width: 100%;
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .site-header {
            background: #1a1a2e;
            color: white;
            padding: 1.5rem 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-family: 'Arial Black', sans-serif;
            font-size: 2.2rem;
            font-weight: 900;
            background: linear-gradient(90deg, #7209b7, #f72585);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            text-decoration: none;
        }
        .my-logo:hover { text-decoration: none; opacity: 0.9; }
        .main-nav ul {
            display: flex;
            list-style: none;
            gap: 2rem;
        }
        .main-nav a {
            color: #e2e8f0;
            font-weight: 600;
            padding: 0.5rem 1rem;
            border-radius: 6px;
        }
        .main-nav a:hover {
            background: rgba(255,255,255,0.1);
            text-decoration: none;
        }
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
        }
        .breadcrumb {
            padding: 1rem 0;
            background: #f1f5f9;
            font-size: 0.9rem;
        }
        .breadcrumb a { color: #64748b; }
        .breadcrumb a:hover { color: #4361ee; }
        main { flex: 1; padding: 2rem 0; }
        .article-header { text-align: center; margin-bottom: 3rem; }
        .article-header h1 {
            font-size: clamp(2.5rem, 5vw, 3.8rem);
            color: #1a1a2e;
            margin-bottom: 1rem;
            line-height: 1.2;
        }
        .article-meta {
            color: #64748b;
            font-size: 0.95rem;
            display: flex;
            justify-content: center;
            gap: 1.5rem;
            flex-wrap: wrap;
            margin-top: 1rem;
        }
        .article-content {
            background: white;
            border-radius: 16px;
            padding: 3rem;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            margin-bottom: 3rem;
        }
        .article-content h2 {
            color: #3a0ca3;
            font-size: 2.2rem;
            margin: 2.5rem 0 1rem;
            padding-bottom: 0.5rem;
            border-bottom: 3px solid #4cc9f0;
        }
        .article-content h3 {
            color: #4361ee;
            font-size: 1.8rem;
            margin: 2rem 0 1rem;
        }
        .article-content h4 {
            color: #7209b7;
            font-size: 1.4rem;
            margin: 1.5rem 0 0.8rem;
        }
        .article-content p {
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
            text-align: justify;
        }
        .article-content strong {
            color: #f72585;
            font-weight: 700;
        }
        .article-content em { color: #06d6a0; font-style: italic; }
        .highlight-box {
            background: linear-gradient(120deg, #e0f7fa, #bbdefb);
            border-left: 5px solid #0288d1;
            padding: 1.5rem;
            margin: 2rem 0;
            border-radius: 0 12px 12px 0;
        }
        .feature-img {
            width: 80%;
            margin: 2.5rem auto;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 15px 35px rgba(0,0,0,0.15);
        }
        .user-interaction {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
        }
        .interaction-card {
            background: white;
            padding: 2rem;
            border-radius: 12px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.06);
        }
        .interaction-card h3 { margin-top: 0; }
        form label {
            display: block;
            margin: 1rem 0 0.5rem;
            font-weight: 600;
        }
        form input, form textarea, form select {
            width: 100%;
            padding: 0.8rem;
            border: 2px solid #cbd5e1;
            border-radius: 8px;
            font-family: inherit;
            transition: border 0.3s;
        }
        form input:focus, form textarea:focus {
            border-color: #4361ee;
            outline: none;
        }
        form button {
            background: linear-gradient(90deg, #4361ee, #3a0ca3);
            color: white;
            border: none;
            padding: 1rem 2rem;
            border-radius: 8px;
            font-weight: bold;
            cursor: pointer;
            margin-top: 1rem;
            transition: transform 0.3s, box-shadow 0.3s;
        }
        form button:hover {
            transform: translateY(-3px);
            box-shadow: 0 7px 14px rgba(67, 97, 238, 0.3);
        }
        .stars { display: flex; gap: 0.5rem; margin: 1rem 0; }
        .star { font-size: 1.8rem; color: #e2e8f0; cursor: pointer; }
        .star:hover, .star.active { color: #ffd700; }
        .site-footer {
            background: #1a1a2e;
            color: #cbd5e1;
            padding: 3rem 0 1.5rem;
            margin-top: auto;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2.5rem;
            margin-bottom: 2rem;
        }
        .footer-section h4 {
            color: white;
            margin-bottom: 1.5rem;
            font-size: 1.3rem;
        }
        friend-link {
            display: block;
            margin-bottom: 0.8rem;
        }
        friend-link a {
            color: #94a3b8;
            text-decoration: none;
        }
        friend-link a:hover { color: #60a5fa; }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid #334155;
            font-size: 0.9rem;
            color: #94a3b8;
        }
        @media (max-width: 768px) {
            .hamburger { display: block; }
            .main-nav ul {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 100%;
                left: 0;
                right: 0;
                background: #1a1a2e;
                padding: 1rem;
                box-shadow: 0 10px 15px rgba(0,0,0,0.2);
            }
            .main-nav.active ul { display: flex; }
            .header-content { flex-wrap: wrap; }
            .article-content { padding: 1.5rem; }
            .article-header h1 { font-size: 2.2rem; }
            .article-content h2 { font-size: 1.8rem; }
            .article-content h3 { font-size: 1.5rem; }
            .user-interaction { grid-template-columns: 1fr; }
        }