* { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
            line-height: 1.6;
            color: #333;
            background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
            min-height: 100vh;
            overflow-x: hidden;
        }
        img { max-width: 100%; height: auto; display: block; }
        :root {
            --primary: #ff6b35; 
            --secondary: #1a237e; 
            --accent: #00acc1; 
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
            --shadow: 0 5px 15px rgba(0,0,0,0.08);
            --radius: 8px;
            --transition: all 0.3s ease;
        }
        .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-color: var(--secondary);
            color: white;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: var(--shadow);
        }
        .header-inner {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 0;
        }
        .my-logo {
            font-size: 1.8rem;
            font-weight: 800;
            color: white;
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 10px;
            transition: var(--transition);
        }
        .my-logo:hover { color: var(--primary); transform: scale(1.05); }
        .my-logo i { color: var(--primary); }
        .breadcrumb {
            background-color: rgba(255,255,255,0.1);
            padding: 0.8rem 0;
            font-size: 0.9rem;
        }
        .breadcrumb ol {
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
        }
        .breadcrumb a { color: #ccc; text-decoration: none; }
        .breadcrumb a:hover { color: white; text-decoration: underline; }
        .breadcrumb li:not(:last-child)::after { content: '/'; margin-left: 0.5rem; color: var(--gray); }
        .main-nav ul {
            display: flex;
            list-style: none;
            gap: 1.5rem;
        }
        .main-nav a {
            color: white;
            text-decoration: none;
            font-weight: 600;
            padding: 0.5rem 0;
            position: relative;
            transition: var(--transition);
        }
        .main-nav a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background-color: var(--primary);
            transition: width 0.3s;
        }
        .main-nav a:hover::after,
        .main-nav a:focus::after { width: 100%; }
        .main-nav a:hover { color: var(--primary); }
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
            padding: 0.5rem;
        }
        .hamburger:focus { outline: 2px solid var(--primary); }
        .main-content {
            padding: 3rem 0;
            background-color: white;
            box-shadow: 0 0 30px rgba(0,0,0,0.05);
            border-radius: var(--radius);
            margin: 2rem auto;
        }
        article { max-width: 900px; margin: 0 auto; padding: 0 20px; }
        h1, h2, h3, h4 {
            color: var(--secondary);
            line-height: 1.2;
            margin-top: 2rem;
            margin-bottom: 1rem;
        }
        h1 {
            font-size: clamp(2.5rem, 5vw, 3.5rem);
            color: var(--primary);
            text-align: center;
            border-bottom: 4px solid var(--accent);
            padding-bottom: 1rem;
            margin-top: 1rem;
        }
        h2 { font-size: 2.2rem; border-left: 5px solid var(--primary); padding-left: 1rem; }
        h3 { font-size: 1.8rem; color: var(--accent); }
        h4 { font-size: 1.4rem; color: var(--dark); }
        p { margin-bottom: 1.5rem; font-size: 1.1rem; }
        .intro { font-size: 1.3rem; font-weight: 500; color: var(--dark); background: #f0f8ff; padding: 1.5rem; border-radius: var(--radius); border-left: 4px solid var(--accent); }
        strong, b { color: var(--secondary); }
        em { font-style: italic; color: var(--gray); }
        .highlight {
            background: linear-gradient(120deg, #ffecb3 0%, #ffecb3 100%);
            padding: 0.2rem 0.5rem;
            border-radius: 4px;
        }
        blockquote {
            border-left: 4px solid var(--primary);
            padding: 1rem 1.5rem;
            margin: 2rem 0;
            background: #f9f9f9;
            font-style: italic;
            color: #555;
        }
        .feature-img {
            margin: 3rem auto;
            text-align: center;
            max-width: 800px;
        }
        .feature-img img {
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            transition: transform 0.5s;
        }
        .feature-img img:hover { transform: scale(1.02); }
        .img-caption { font-size: 0.95rem; color: var(--gray); margin-top: 0.5rem; font-style: italic; }
        .content-link {
            color: var(--accent);
            text-decoration: none;
            font-weight: 600;
            border-bottom: 1px dotted var(--accent);
            transition: var(--transition);
        }
        .content-link:hover {
            color: var(--primary);
            border-bottom-style: solid;
        }
        .interaction-module {
            background: #f8f9fa;
            border-radius: var(--radius);
            padding: 2rem;
            margin: 3rem 0;
            border: 1px solid #dee2e6;
        }
        .module-title { margin-top: 0; color: var(--secondary); text-align: center; }
        .form-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin-top: 1.5rem;
        }
        .form-group label { display: block; margin-bottom: 0.5rem; font-weight: 600; color: var(--dark); }
        .form-control {
            width: 100%;
            padding: 0.8rem 1rem;
            border: 1px solid #ced4da;
            border-radius: var(--radius);
            font-size: 1rem;
            transition: var(--transition);
        }
        .form-control:focus {
            outline: none;
            border-color: var(--accent);
            box-shadow: 0 0 0 3px rgba(0,172,193,0.2);
        }
        textarea.form-control { min-height: 120px; resize: vertical; }
        .rating {
            display: flex;
            gap: 0.5rem;
            justify-content: center;
            margin: 1rem 0;
        }
        .rating input { display: none; }
        .rating label {
            font-size: 2rem;
            color: #ddd;
            cursor: pointer;
            transition: var(--transition);
        }
        .rating input:checked ~ label,
        .rating label:hover,
        .rating label:hover ~ label { color: #ffc107; }
        .btn {
            display: inline-block;
            background-color: var(--primary);
            color: white;
            padding: 0.9rem 2rem;
            border: none;
            border-radius: var(--radius);
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
            text-decoration: none;
        }
        .btn:hover, .btn:focus {
            background-color: #e55a2b;
            transform: translateY(-3px);
            box-shadow: 0 7px 14px rgba(255,107,53,0.3);
        }
        .btn-block { width: 100%; }
        .site-footer {
            background-color: var(--secondary);
            color: white;
            padding: 3rem 0 1.5rem;
            margin-top: 4rem;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin-bottom: 2rem;
        }
        .footer-logo { font-size: 1.8rem; font-weight: 800; margin-bottom: 1rem; }
        .footer-links h4 { color: white; margin-bottom: 1rem; }
        .footer-links ul { list-style: none; }
        .footer-links li { margin-bottom: 0.7rem; }
        .footer-links a {
            color: #ccc;
            text-decoration: none;
            transition: var(--transition);
        }
        .footer-links a:hover { color: var(--primary); padding-left: 5px; }
        friend-link {
            display: block;
            background: rgba(255,255,255,0.05);
            padding: 1.5rem;
            border-radius: var(--radius);
            margin-top: 2rem;
        }
        friend-link h4 { color: var(--primary); margin-top: 0; }
        friend-link ul { list-style: none; display: flex; flex-wrap: wrap; gap: 1rem; }
        friend-link a {
            color: white;
            text-decoration: none;
            background: rgba(255,255,255,0.1);
            padding: 0.5rem 1rem;
            border-radius: 50px;
            transition: var(--transition);
        }
        friend-link a:hover { background: var(--primary); color: var(--secondary); }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid rgba(255,255,255,0.1);
            color: #aaa;
            font-size: 0.9rem;
        }
        .update-time { color: var(--accent); font-weight: bold; }
        @media (max-width: 992px) {
            .main-nav ul { gap: 1rem; }
        }
        @media (max-width: 768px) {
            .hamburger { display: block; }
            .main-nav {
                position: fixed;
                top: 100%;
                left: 0;
                width: 100%;
                background-color: var(--secondary);
                transition: var(--transition);
                opacity: 0;
                visibility: hidden;
                box-shadow: 0 10px 20px rgba(0,0,0,0.2);
            }
            .main-nav.active {
                top: 100%;
                opacity: 1;
                visibility: visible;
            }
            .main-nav ul {
                flex-direction: column;
                padding: 2rem;
                gap: 0;
            }
            .main-nav li { margin-bottom: 1rem; }
            .main-nav a { display: block; padding: 0.8rem 0; border-bottom: 1px solid rgba(255,255,255,0.1); }
            .main-nav a::after { display: none; }
            h2 { font-size: 1.8rem; }
            h3 { font-size: 1.5rem; }
            .form-grid { grid-template-columns: 1fr; }
        }
        @media (max-width: 480px) {
            .container { padding: 0 15px; }
            h1 { font-size: 2.2rem; }
            .interaction-module { padding: 1.5rem; }
        }