* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
            background: #fafafa;
            color: #1a1a2e;
            line-height: 1.7;
            font-size: 16px;
        }
        a {
            color: #0f4c75;
            text-decoration: none;
            transition: color 0.2s;
        }
        a:hover {
            color: #1b98a0;
            text-decoration: underline;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
            border-radius: 12px;
        }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        header {
            background: linear-gradient(135deg, #0f4c75 0%, #1b98a0 100%);
            color: #fff;
            padding: 16px 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 12px;
        }
        .my-logo {
            font-size: 1.8rem;
            font-weight: 800;
            letter-spacing: -0.5px;
            color: #fff;
            background: rgba(255, 255, 255, 0.12);
            padding: 6px 18px;
            border-radius: 40px;
            display: inline-block;
            transition: background 0.3s;
            text-decoration: none !important;
        }
        .my-logo:hover {
            background: rgba(255, 255, 255, 0.25);
            text-decoration: none !important;
        }
        .my-logo span {
            color: #f9c74f;
        }
        .nav-wrapper {
            display: flex;
            align-items: center;
            gap: 20px;
        }
        .nav-list {
            display: flex;
            list-style: none;
            gap: 8px;
            flex-wrap: wrap;
        }
        .nav-list li a {
            color: #fff;
            padding: 8px 16px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 0.92rem;
            transition: background 0.25s, transform 0.2s;
            display: inline-block;
            text-decoration: none !important;
        }
        .nav-list li a:hover {
            background: rgba(255, 255, 255, 0.2);
            transform: translateY(-1px);
            text-decoration: none !important;
        }
        .nav-list li a i {
            margin-right: 6px;
        }
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: #fff;
            font-size: 1.8rem;
            cursor: pointer;
            padding: 4px 8px;
            border-radius: 8px;
            transition: background 0.2s;
        }
        .hamburger:hover {
            background: rgba(255, 255, 255, 0.15);
        }
        .breadcrumb {
            background: #fff;
            padding: 12px 0;
            border-bottom: 1px solid #e9ecef;
            font-size: 0.88rem;
        }
        .breadcrumb ol {
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            gap: 6px 12px;
            align-items: center;
        }
        .breadcrumb ol li+li::before {
            content: "›";
            margin-right: 12px;
            color: #999;
            font-size: 1.2rem;
        }
        .breadcrumb a {
            color: #0f4c75;
        }
        .breadcrumb .current {
            color: #666;
            font-weight: 500;
        }
        main {
            padding: 40px 0 60px;
        }
        h1 {
            font-size: 2.8rem;
            font-weight: 800;
            color: #0f4c75;
            line-height: 1.2;
            margin-bottom: 16px;
            letter-spacing: -1px;
        }
        h2 {
            font-size: 2rem;
            font-weight: 700;
            color: #1a1a2e;
            margin-top: 56px;
            margin-bottom: 20px;
            border-left: 6px solid #1b98a0;
            padding-left: 20px;
        }
        h3 {
            font-size: 1.5rem;
            font-weight: 600;
            color: #0f4c75;
            margin-top: 36px;
            margin-bottom: 14px;
        }
        h4 {
            font-size: 1.2rem;
            font-weight: 600;
            color: #2d4059;
            margin-top: 24px;
            margin-bottom: 10px;
        }
        p {
            margin-bottom: 18px;
            color: #2d3436;
        }
        .lead {
            font-size: 1.2rem;
            color: #444;
            font-weight: 400;
            margin-bottom: 30px;
            line-height: 1.8;
        }
        .content-grid {
            display: grid;
            grid-template-columns: 1fr 300px;
            gap: 48px;
        }
        @media (max-width: 992px) {
            .content-grid {
                grid-template-columns: 1fr;
            }
        }
        .article-body {
            background: #fff;
            padding: 40px 40px 50px;
            border-radius: 20px;
            box-shadow: 0 2px 30px rgba(0, 0, 0, 0.05);
        }
        @media (max-width: 768px) {
            .article-body {
                padding: 24px 18px;
            }
            h1 {
                font-size: 1.9rem;
            }
            h2 {
                font-size: 1.5rem;
                padding-left: 14px;
            }
            h3 {
                font-size: 1.25rem;
            }
        }
        .sidebar {
            position: sticky;
            top: 100px;
            align-self: start;
        }
        .sidebar-card {
            background: #fff;
            border-radius: 16px;
            padding: 24px;
            box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
            margin-bottom: 24px;
        }
        .sidebar-card h4 {
            margin-top: 0;
            font-size: 1.1rem;
            border-bottom: 2px solid #1b98a0;
            padding-bottom: 10px;
            margin-bottom: 14px;
        }
        .sidebar-card ul {
            list-style: none;
            padding: 0;
        }
        .sidebar-card ul li {
            padding: 8px 0;
            border-bottom: 1px solid #f0f0f0;
        }
        .sidebar-card ul li a {
            font-weight: 500;
        }
        .featured-image {
            margin: 30px 0 36px;
            border-radius: 16px;
            overflow: hidden;
            box-shadow: 0 4px 30px rgba(0, 0, 0, 0.08);
        }
        .featured-image figcaption {
            background: #f8f9fa;
            padding: 12px 20px;
            font-size: 0.88rem;
            color: #555;
            font-style: italic;
        }
        .search-box {
            background: #f0f7fb;
            border-radius: 16px;
            padding: 28px 30px;
            margin: 32px 0 24px;
        }
        .search-box form {
            display: flex;
            gap: 12px;
            flex-wrap: wrap;
            align-items: center;
        }
        .search-box input[type="text"] {
            flex: 1;
            min-width: 200px;
            padding: 14px 20px;
            border: 2px solid #dce8f0;
            border-radius: 50px;
            font-size: 1rem;
            outline: none;
            transition: border 0.3s;
        }
        .search-box input[type="text"]:focus {
            border-color: #1b98a0;
        }
        .search-box button {
            padding: 14px 32px;
            background: #0f4c75;
            color: #fff;
            border: none;
            border-radius: 50px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: background 0.3s, transform 0.2s;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .search-box button:hover {
            background: #1b98a0;
            transform: translateY(-2px);
        }
        .user-feedback {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 28px;
            margin: 40px 0 20px;
        }
        @media (max-width: 700px) {
            .user-feedback {
                grid-template-columns: 1fr;
            }
        }
        .feedback-card {
            background: #f8faff;
            border-radius: 18px;
            padding: 28px 30px;
            border: 1px solid #e8f0f8;
        }
        .feedback-card h4 {
            margin-top: 0;
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.2rem;
        }
        .feedback-card form {
            display: flex;
            flex-direction: column;
            gap: 14px;
            margin-top: 10px;
        }
        .feedback-card textarea {
            padding: 14px 16px;
            border: 2px solid #dce8f0;
            border-radius: 12px;
            font-size: 0.95rem;
            resize: vertical;
            min-height: 90px;
            font-family: inherit;
            outline: none;
            transition: border 0.3s;
        }
        .feedback-card textarea:focus {
            border-color: #1b98a0;
        }
        .feedback-card input[type="text"],
        .feedback-card input[type="number"] {
            padding: 12px 16px;
            border: 2px solid #dce8f0;
            border-radius: 12px;
            font-size: 0.95rem;
            outline: none;
            transition: border 0.3s;
            width: 100%;
        }
        .feedback-card input:focus {
            border-color: #1b98a0;
        }
        .feedback-card .star-row {
            display: flex;
            gap: 6px;
            font-size: 1.6rem;
            color: #f9c74f;
        }
        .feedback-card button {
            padding: 12px 24px;
            background: #0f4c75;
            color: #fff;
            border: none;
            border-radius: 50px;
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: background 0.3s, transform 0.2s;
            align-self: flex-start;
        }
        .feedback-card button:hover {
            background: #1b98a0;
            transform: translateY(-2px);
        }
        .last-updated {
            display: inline-block;
            background: #eef5f9;
            padding: 8px 20px;
            border-radius: 40px;
            font-size: 0.85rem;
            color: #0f4c75;
            font-weight: 500;
            margin-bottom: 24px;
        }
        .last-updated i {
            margin-right: 6px;
        }
        footer {
            background: #0f1b2d;
            color: #ccddee;
            padding: 48px 0 30px;
            margin-top: 40px;
        }
        footer a {
            color: #88c0d0;
        }
        footer a:hover {
            color: #f9c74f;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 36px;
        }
        @media (max-width: 768px) {
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 28px;
            }
        }
        .footer-grid h5 {
            color: #f9c74f;
            font-size: 1.1rem;
            margin-bottom: 16px;
            letter-spacing: 0.5px;
        }
        .footer-grid p {
            color: #aabccd;
            font-size: 0.92rem;
        }
        .footer-links {
            list-style: none;
            padding: 0;
        }
        .footer-links li {
            padding: 5px 0;
        }
        .footer-links li a {
            font-size: 0.92rem;
        }
        friend-link {
            display: block;
            background: #152238;
            padding: 22px 28px;
            border-radius: 14px;
            margin: 20px 0 28px;
            font-size: 0.95rem;
            color: #aabccd;
        }
        friend-link a {
            color: #88c0d0;
            margin: 0 6px;
            font-weight: 500;
        }
        friend-link a:hover {
            color: #f9c74f;
        }
        .copyright {
            border-top: 1px solid #1e3450;
            padding-top: 24px;
            text-align: center;
            font-size: 0.85rem;
            color: #7a95af;
        }
        .copyright a {
            color: #88c0d0;
        }
        .highlight-box {
            background: #f0f9f9;
            border-left: 6px solid #1b98a0;
            padding: 20px 28px;
            border-radius: 0 16px 16px 0;
            margin: 28px 0;
        }
        .highlight-box p:last-child {
            margin-bottom: 0;
        }
        .emoji-big {
            font-size: 1.8rem;
            display: inline-block;
            margin-right: 6px;
        }
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
            gap: 16px;
            margin: 24px 0;
        }
        .stat-item {
            background: #f4f9fc;
            padding: 18px 14px;
            border-radius: 14px;
            text-align: center;
            font-weight: 600;
        }
        .stat-item .num {
            font-size: 2rem;
            color: #0f4c75;
            display: block;
        }
        .stat-item .label {
            font-size: 0.85rem;
            color: #555;
            margin-top: 4px;
        }
        @media (max-width: 768px) {
            .hamburger {
                display: block;
            }
            .nav-list {
                display: none;
                width: 100%;
                flex-direction: column;
                background: rgba(255, 255, 255, 0.06);
                padding: 16px 12px;
                border-radius: 16px;
                margin-top: 8px;
            }
            .nav-list.active {
                display: flex;
            }
            .nav-list li a {
                padding: 10px 14px;
                width: 100%;
            }
            .nav-wrapper {
                flex-wrap: wrap;
            }
        }
        @media (max-width: 480px) {
            .header-inner {
                flex-direction: column;
                align-items: stretch;
            }
            .my-logo {
                text-align: center;
                font-size: 1.4rem;
            }
            .search-box form {
                flex-direction: column;
            }
            .search-box input[type="text"] {
                min-width: auto;
                width: 100%;
            }
            .search-box button {
                width: 100%;
                justify-content: center;
            }
            .feedback-card button {
                width: 100%;
                text-align: center;
            }
        }
        html {
            scroll-behavior: smooth;
        }
        .toc {
            background: #f4f9fc;
            border-radius: 16px;
            padding: 24px 28px;
            margin: 24px 0 32px;
        }
        .toc h4 {
            margin-top: 0;
        }
        .toc ul {
            columns: 2;
            column-gap: 30px;
            list-style: none;
            padding: 0;
        }
        .toc ul li {
            padding: 4px 0;
            break-inside: avoid;
        }
        .toc ul li a {
            font-weight: 500;
        }
        @media (max-width: 600px) {
            .toc ul {
                columns: 1;
            }
        }
        .btn-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background: #0f4c75;
            color: #fff;
            width: 48px;
            height: 48px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.4rem;
            box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
            transition: background 0.3s, transform 0.2s;
            z-index: 999;
            border: none;
            cursor: pointer;
            text-decoration: none !important;
        }
        .btn-top:hover {
            background: #1b98a0;
            transform: translateY(-3px);
            text-decoration: none !important;
        }