*,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        html {
            scroll-behavior: smooth;
            font-size: 16px;
        }
        body {
            font-family: 'Segoe UI', Roboto, -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial, sans-serif;
            background: #f4f7fc;
            color: #1a2639;
            line-height: 1.7;
            padding: 0;
            margin: 0;
        }
        a {
            color: #1a5276;
            text-decoration: none;
            transition: color 0.2s;
        }
        a:hover {
            color: #f39c12;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        ul,
        ol {
            padding-left: 1.5rem;
        }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 1.5rem;
        }
        header {
            background: linear-gradient(135deg, #0d2137 0%, #1a5276 100%);
            color: #fff;
            padding: 1rem 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: 0.75rem;
        }
        .my-logo {
            font-size: 1.8rem;
            font-weight: 800;
            letter-spacing: 1px;
            color: #fff;
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .my-logo i {
            color: #f39c12;
            font-size: 2rem;
        }
        .my-logo span {
            color: #f39c12;
        }
        .my-logo:hover {
            color: #f39c12;
        }
        .nav-toggle {
            display: none;
            font-size: 1.6rem;
            background: none;
            border: none;
            color: #fff;
            cursor: pointer;
            padding: 0.25rem 0.5rem;
            border-radius: 6px;
            transition: background 0.2s;
        }
        .nav-toggle:hover {
            background: rgba(255, 255, 255, 0.1);
        }
        .main-nav {
            display: flex;
            align-items: center;
            gap: 1.2rem;
            flex-wrap: wrap;
        }
        .main-nav a {
            color: #e0e8f0;
            font-weight: 500;
            font-size: 0.95rem;
            padding: 0.4rem 0.2rem;
            border-bottom: 2px solid transparent;
            transition: all 0.2s;
        }
        .main-nav a:hover {
            color: #f39c12;
            border-bottom-color: #f39c12;
        }
        .main-nav a i {
            margin-right: 0.35rem;
        }
        .breadcrumb {
            background: #eaf0f8;
            padding: 0.65rem 0;
            font-size: 0.9rem;
            border-bottom: 1px solid #d0dce8;
        }
        .breadcrumb ol {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            padding: 0;
            gap: 0.3rem 0.6rem;
        }
        .breadcrumb li+li::before {
            content: "›";
            color: #7f8c9b;
            margin-right: 0.6rem;
            font-weight: 600;
        }
        .breadcrumb a {
            color: #1a5276;
        }
        .breadcrumb .current {
            color: #7f8c9b;
            font-weight: 500;
        }
        main {
            padding: 2.5rem 0 3rem;
        }
        .hero {
            text-align: center;
            padding: 2rem 0 2.5rem;
            background: linear-gradient(180deg, #eaf0f8 0%, #f4f7fc 100%);
            border-radius: 20px;
            margin-bottom: 2.5rem;
        }
        .hero h1 {
            font-size: 2.8rem;
            font-weight: 800;
            color: #0d2137;
            line-height: 1.2;
            margin-bottom: 0.75rem;
        }
        .hero h1 i {
            color: #f39c12;
        }
        .hero .subtitle {
            font-size: 1.2rem;
            color: #2c3e50;
            max-width: 750px;
            margin: 0 auto 1rem;
        }
        .hero .meta {
            font-size: 0.95rem;
            color: #5d6d7e;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 1.5rem;
        }
        .hero .meta i {
            margin-right: 0.4rem;
            color: #1a5276;
        }
        .content-section {
            background: #fff;
            border-radius: 18px;
            padding: 2.2rem 2.5rem;
            margin-bottom: 2.2rem;
            box-shadow: 0 6px 24px rgba(0, 0, 0, 0.04);
            transition: box-shadow 0.25s;
        }
        .content-section:hover {
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.07);
        }
        .content-section h2 {
            font-size: 2rem;
            font-weight: 700;
            color: #0d2137;
            border-left: 6px solid #f39c12;
            padding-left: 1.2rem;
            margin-bottom: 1.5rem;
        }
        .content-section h2 i {
            color: #1a5276;
            margin-right: 0.5rem;
        }
        .content-section h3 {
            font-size: 1.5rem;
            font-weight: 600;
            color: #1a5276;
            margin-top: 2rem;
            margin-bottom: 0.8rem;
        }
        .content-section h4 {
            font-size: 1.2rem;
            font-weight: 600;
            color: #2c3e50;
            margin-top: 1.5rem;
            margin-bottom: 0.5rem;
        }
        .content-section p {
            margin-bottom: 1.2rem;
            color: #2c3e50;
        }
        .content-section p strong {
            color: #0d2137;
        }
        .content-section ul,
        .content-section ol {
            margin-bottom: 1.2rem;
            color: #2c3e50;
        }
        .content-section li {
            margin-bottom: 0.4rem;
        }
        .feature-img {
            border-radius: 16px;
            margin: 1.8rem auto;
            box-shadow: 0 8px 28px rgba(0, 0, 0, 0.08);
            max-width: 100%;
        }
        .img-caption {
            text-align: center;
            font-size: 0.9rem;
            color: #5d6d7e;
            margin-top: -0.8rem;
            margin-bottom: 1.8rem;
        }
        .highlight-box {
            background: #eaf4fc;
            border-left: 6px solid #1a5276;
            padding: 1.5rem 2rem;
            border-radius: 12px;
            margin: 1.8rem 0;
        }
        .highlight-box h4 {
            margin-top: 0;
            color: #0d2137;
        }
        .highlight-box i {
            color: #f39c12;
            margin-right: 0.5rem;
        }
        .search-block {
            background: #fff;
            border-radius: 18px;
            padding: 2rem 2.5rem;
            margin-bottom: 2.2rem;
            box-shadow: 0 6px 24px rgba(0, 0, 0, 0.04);
        }
        .search-block h2 {
            font-size: 1.8rem;
            font-weight: 700;
            color: #0d2137;
            margin-bottom: 1rem;
        }
        .search-form {
            display: flex;
            gap: 0.8rem;
            flex-wrap: wrap;
        }
        .search-form input[type="text"] {
            flex: 1 1 280px;
            padding: 0.85rem 1.2rem;
            border: 2px solid #d0dce8;
            border-radius: 40px;
            font-size: 1rem;
            outline: none;
            transition: border 0.25s;
        }
        .search-form input[type="text"]:focus {
            border-color: #1a5276;
        }
        .search-form button {
            background: #1a5276;
            color: #fff;
            border: none;
            padding: 0.85rem 2rem;
            border-radius: 40px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: background 0.25s, transform 0.15s;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .search-form button:hover {
            background: #0d2137;
            transform: translateY(-2px);
        }
        .feedback-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
            margin-top: 1.5rem;
        }
        .feedback-card {
            background: #f8faff;
            border-radius: 16px;
            padding: 1.8rem 2rem;
            border: 1px solid #e0e8f0;
        }
        .feedback-card h3 {
            font-size: 1.4rem;
            margin-top: 0;
            margin-bottom: 1rem;
            color: #0d2137;
        }
        .feedback-card h3 i {
            color: #f39c12;
            margin-right: 0.5rem;
        }
        .feedback-card form {
            display: flex;
            flex-direction: column;
            gap: 0.9rem;
        }
        .feedback-card label {
            font-weight: 600;
            color: #2c3e50;
        }
        .feedback-card textarea,
        .feedback-card input[type="number"],
        .feedback-card input[type="text"] {
            padding: 0.75rem 1rem;
            border: 2px solid #d0dce8;
            border-radius: 12px;
            font-size: 0.95rem;
            font-family: inherit;
            outline: none;
            transition: border 0.25s;
            width: 100%;
        }
        .feedback-card textarea:focus,
        .feedback-card input:focus {
            border-color: #1a5276;
        }
        .feedback-card textarea {
            min-height: 100px;
            resize: vertical;
        }
        .feedback-card .star-select {
            display: flex;
            gap: 0.6rem;
            font-size: 1.8rem;
            color: #d0dce8;
            cursor: pointer;
            flex-wrap: wrap;
        }
        .feedback-card .star-select i {
            transition: color 0.2s, transform 0.15s;
        }
        .feedback-card .star-select i:hover,
        .feedback-card .star-select i.active {
            color: #f39c12;
            transform: scale(1.15);
        }
        .feedback-card button {
            background: #1a5276;
            color: #fff;
            border: none;
            padding: 0.85rem 1.8rem;
            border-radius: 40px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: background 0.25s, transform 0.15s;
            align-self: flex-start;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .feedback-card button:hover {
            background: #0d2137;
            transform: translateY(-2px);
        }
        .toc {
            background: #eaf4fc;
            border-radius: 16px;
            padding: 1.8rem 2.2rem;
            margin-bottom: 2.5rem;
            border: 1px solid #d0dce8;
        }
        .toc h2 {
            font-size: 1.6rem;
            margin-bottom: 1rem;
            color: #0d2137;
            border-left: 6px solid #f39c12;
            padding-left: 1rem;
        }
        .toc ol {
            columns: 2 280px;
            column-gap: 2rem;
            list-style: none;
            counter-reset: toc-counter;
            padding: 0;
        }
        .toc ol li {
            counter-increment: toc-counter;
            margin-bottom: 0.5rem;
            break-inside: avoid;
        }
        .toc ol li::before {
            content: counter(toc-counter) ". ";
            font-weight: 700;
            color: #1a5276;
        }
        .toc ol li a {
            color: #1a5276;
            font-weight: 500;
        }
        .toc ol li a:hover {
            color: #f39c12;
            text-decoration: underline;
        }
        footer {
            background: #0d2137;
            color: #c8d8e8;
            padding: 2.5rem 0 1.5rem;
            margin-top: 1.5rem;
        }
        .footer-inner {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
        }
        footer h3 {
            color: #fff;
            font-size: 1.3rem;
            margin-bottom: 0.8rem;
            font-weight: 600;
        }
        footer a {
            color: #a0b8d0;
        }
        footer a:hover {
            color: #f39c12;
        }
        friend-link {
            display: block;
            margin-bottom: 0.5rem;
        }
        friend-link a {
            display: inline-block;
            padding: 0.3rem 0.8rem;
            background: rgba(255, 255, 255, 0.06);
            border-radius: 30px;
            font-size: 0.95rem;
            transition: background 0.2s, color 0.2s;
        }
        friend-link a:hover {
            background: rgba(255, 255, 255, 0.12);
            color: #f39c12;
        }
        .copyright {
            text-align: center;
            padding-top: 1.8rem;
            margin-top: 1.8rem;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
            font-size: 0.9rem;
            color: #8899aa;
            grid-column: 1 / -1;
        }
        .copyright strong {
            color: #d0dce8;
        }
        @media (max-width: 900px) {
            .feedback-grid {
                grid-template-columns: 1fr;
            }
            .footer-inner {
                grid-template-columns: 1fr;
                gap: 1.5rem;
            }
            .hero h1 {
                font-size: 2rem;
            }
            .content-section {
                padding: 1.5rem 1.2rem;
            }
            .search-block {
                padding: 1.5rem 1.2rem;
            }
        }
        @media (max-width: 700px) {
            .header-inner {
                flex-wrap: wrap;
            }
            .nav-toggle {
                display: block;
            }
            .main-nav {
                display: none;
                width: 100%;
                flex-direction: column;
                align-items: flex-start;
                gap: 0.5rem;
                padding: 1rem 0 0.5rem;
                border-top: 1px solid rgba(255, 255, 255, 0.1);
                margin-top: 0.5rem;
            }
            .main-nav.open {
                display: flex;
            }
            .main-nav a {
                padding: 0.4rem 0;
                width: 100%;
                border-bottom: 1px solid rgba(255, 255, 255, 0.05);
            }
            .hero h1 {
                font-size: 1.7rem;
            }
            .hero .subtitle {
                font-size: 1rem;
            }
            .toc ol {
                columns: 1;
            }
            .container {
                padding: 0 1rem;
            }
            .content-section {
                padding: 1.2rem 1rem;
                border-radius: 14px;
            }
            .search-block {
                padding: 1.2rem 1rem;
            }
            .feedback-card {
                padding: 1.2rem 1rem;
            }
            .highlight-box {
                padding: 1.2rem 1.2rem;
            }
        }
        @media (max-width: 480px) {
            .my-logo {
                font-size: 1.4rem;
            }
            .my-logo i {
                font-size: 1.5rem;
            }
            .hero h1 {
                font-size: 1.4rem;
            }
            .content-section h2 {
                font-size: 1.5rem;
                padding-left: 0.8rem;
            }
            .content-section h3 {
                font-size: 1.2rem;
            }
            .search-form button {
                padding: 0.7rem 1.2rem;
                font-size: 0.9rem;
            }
            .search-form input[type="text"] {
                padding: 0.7rem 1rem;
                font-size: 0.9rem;
            }
        }
        .text-center {
            text-align: center;
        }
        .mt-1 {
            margin-top: 1rem;
        }
        .mb-1 {
            margin-bottom: 1rem;
        }
        .flex-center {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
        }
        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            border: 0;
        }