/* roulang page: index */
/* CSS Design System */
        :root {
            --primary-color: #007bff;
            --secondary-color: #6c757d;
            --accent-color: #28a745;
            --background-color: #f8f9fa;
            --surface-color: #ffffff;
            --text-color: #343a40;
            --muted-text-color: #6c757d;
            --border-color: #dee2e6;
            --border-radius: 8px;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
            --shadow-md: 0 4px 10px rgba(0, 0, 0, 0.15);
            --spacing-xs: 0.5rem;
            --spacing-sm: 1rem;
            --spacing-md: 1.5rem;
            --spacing-lg: 2rem;
            --container-max-width: 1200px;
            --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            --heading-font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            --transition-fast: 0.2s ease-in-out;
        }

        /* Reset & Base */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            font-size: 16px;
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-family);
            line-height: 1.7;
            color: var(--text-color);
            background-color: var(--background-color);
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        a {
            color: var(--primary-color);
            text-decoration: none;
            transition: var(--transition-fast);
        }

        a:hover {
            color: #0056b3;
            text-decoration: underline;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        button {
            font-family: var(--font-family);
            cursor: pointer;
            border: none;
            border-radius: var(--border-radius);
            transition: var(--transition-fast);
        }

        h1, h2, h3, h4, h5, h6 {
            font-family: var(--heading-font-family);
            line-height: 1.3;
            margin-bottom: var(--spacing-sm);
            color: var(--text-color);
        }

        h1 { font-size: 2.5rem; }
        h2 { font-size: 2rem; }
        h3 { font-size: 1.75rem; }
        h4 { font-size: 1.5rem; }
        h5 { font-size: 1.25rem; }
        h6 { font-size: 1rem; }

        .container {
            max-width: var(--container-max-width);
            margin-left: auto;
            margin-right: auto;
            padding-left: var(--spacing-md);
            padding-right: var(--spacing-md);
            width: 100%;
        }

        /* Header & Navigation */
        header {
            background-color: var(--surface-color);
            box-shadow: var(--shadow-sm);
            padding: var(--spacing-sm) 0;
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--primary-color);
            text-decoration: none;
        }

        .logo:hover {
            text-decoration: none;
            color: #0056b3;
        }

        .nav-links {
            display: flex;
            list-style: none;
        }

        .nav-links li {
            margin-left: var(--spacing-md);
        }

        .nav-links a {
            color: var(--text-color);
            font-weight: 500;
            padding: 0.5rem 0;
            position: relative;
            text-decoration: none;
            transition: var(--transition-fast);
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: var(--primary-color);
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: var(--primary-color);
            transition: var(--transition-fast);
        }

        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }

        /* Mobile Navigation */
        .mobile-nav-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.8rem;
            color: var(--text-color);
        }

        @media (max-width: 768px) {
            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background-color: var(--surface-color);
                box-shadow: var(--shadow-md);
                padding: var(--spacing-sm);
            }
            .nav-links.active {
                display: flex;
            }
            .nav-links li {
                margin: var(--spacing-sm) 0;
            }
            .mobile-nav-toggle {
                display: block;
            }
        }

        /* Hero Section */
        .hero {
            background-image: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            color: #ffffff;
            padding: var(--spacing-lg) 0;
            text-align: center;
            min-height: 60vh;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
        }

        .hero-content {
            max-width: 800px;
            z-index: 1;
        }

        .hero h1 {
            font-size: 3.5rem;
            margin-bottom: var(--spacing-sm);
            color: #ffffff;
            letter-spacing: 1px;
        }

        .hero p {
            font-size: 1.2rem;
            color: rgba(255, 255, 255, 0.9);
            margin-bottom: var(--spacing-lg);
            line-height: 1.5;
        }

        .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: #ffffff;
            padding: var(--spacing-sm) var(--spacing-lg);
            font-size: 1.1rem;
            font-weight: 600;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-sm);
            transition: var(--transition-fast);
            text-decoration: none;
        }

        .cta-button:hover {
            background-color: #218838;
            box-shadow: var(--shadow-md);
            text-decoration: none;
            transform: translateY(-2px);
        }

        /* Section Styling */
        section {
            padding: var(--spacing-lg) 0;
        }

        .section-title {
            text-align: center;
            margin-bottom: var(--spacing-lg);
            font-size: 2.2rem;
            color: var(--text-color);
        }

        .section-subtitle {
            text-align: center;
            color: var(--muted-text-color);
            font-size: 1.1rem;
            margin-bottom: var(--spacing-lg);
        }

        /* Content Blocks */
        .content-block {
            background-color: var(--surface-color);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-sm);
            padding: var(--spacing-lg);
            margin-bottom: var(--spacing-md);
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: var(--spacing-lg);
        }

        .content-block-text {
            flex: 1;
            min-width: 300px;
        }

        .content-block-image {
            flex: 1;
            min-width: 300px;
            text-align: center;
        }

        .content-block-image img {
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-md);
        }

        .content-block h3 {
            font-size: 1.8rem;
            margin-bottom: var(--spacing-sm);
            color: var(--primary-color);
        }

        .content-block p {
            margin-bottom: var(--spacing-md);
        }

        /* Feature Cards */
        .feature-cards {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: var(--spacing-lg);
        }

        .feature-card {
            background-color: var(--surface-color);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-sm);
            padding: var(--spacing-md);
            text-align: center;
            transition: var(--transition-fast);
            display: flex;
            flex-direction: column;
        }

        .feature-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-md);
        }

        .feature-card img {
            width: 60px;
            height: 60px;
            margin: 0 auto var(--spacing-md);
            object-fit: contain;
        }

        .feature-card h4 {
            font-size: 1.3rem;
            margin-bottom: var(--spacing-sm);
            color: var(--text-color);
        }

        .feature-card p {
            font-size: 0.95rem;
            color: var(--muted-text-color);
            flex-grow: 1;
            margin-bottom: var(--spacing-md);
        }

        /* Latest Posts Section */
        .latest-posts .section-title {
            color: var(--text-color);
        }
        .latest-posts .section-subtitle {
            color: var(--muted-text-color);
        }

        .post-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: var(--spacing-lg);
        }

        .post-item {
            background-color: var(--surface-color);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-sm);
            overflow: hidden;
            transition: var(--transition-fast);
            display: flex;
            flex-direction: column;
        }

        .post-item:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-md);
        }

        .post-item img {
            width: 100%;
            height: 200px;
            object-fit: cover;
        }

        .post-content {
            padding: var(--spacing-md);
            flex-grow: 1;
        }

        .post-content h4 {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-sm);
        }

        .post-meta {
            font-size: 0.85rem;
            color: var(--muted-text-color);
            margin-bottom: var(--spacing-sm);
            display: flex;
            justify-content: space-between;
        }

        .post-summary {
            font-size: 0.95rem;
            color: var(--muted-text-color);
            margin-bottom: var(--spacing-md);
        }

        .post-link {
            display: inline-block;
            font-weight: 600;
            color: var(--primary-color);
            margin-top: auto; /* Push to bottom */
        }
        .post-link:hover {
            color: #0056b3;
            text-decoration: none;
        }

        /* FAQ Section */
        .faq-section {
            background-color: var(--surface-color);
            padding: var(--spacing-lg) 0;
        }

        .faq-item {
            margin-bottom: var(--spacing-sm);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-sm);
        }

        .faq-question {
            background-color: var(--surface-color);
            color: var(--text-color);
            padding: var(--spacing-md) var(--spacing-lg);
            cursor: pointer;
            font-weight: 600;
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-radius: var(--border-radius);
            position: relative;
            transition: var(--transition-fast);
        }
        .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            transition: var(--transition-fast);
        }

        .faq-item.open .faq-question::after {
            content: '-';
        }
        .faq-item.open .faq-question {
            border-bottom-left-radius: 0;
            border-bottom-right-radius: 0;
        }


        .faq-answer {
            background-color: var(--background-color);
            color: var(--muted-text-color);
            padding: 0 var(--spacing-lg);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out;
            border-bottom-left-radius: var(--border-radius);
            border-bottom-right-radius: var(--border-radius);
        }
        .faq-item.open .faq-answer {
            max-height: 300px; /* Adjust as needed */
            padding: var(--spacing-md) var(--spacing-lg);
            border-bottom-left-radius: var(--border-radius);
            border-bottom-right-radius: var(--border-radius);
        }

        /* Call to Action */
        .cta-section {
            background-color: var(--primary-color);
            color: #ffffff;
            text-align: center;
            padding: var(--spacing-lg) 0;
        }

        .cta-section h2 {
            font-size: 2.5rem;
            margin-bottom: var(--spacing-sm);
            color: #ffffff;
        }

        .cta-section p {
            font-size: 1.1rem;
            margin-bottom: var(--spacing-lg);
            opacity: 0.9;
        }

        .cta-section .cta-button {
            background-color: var(--accent-color);
            color: #ffffff;
            padding: var(--spacing-sm) var(--spacing-lg);
            font-size: 1.2rem;
            font-weight: 700;
        }

        .cta-section .cta-button:hover {
            background-color: #218838;
            transform: translateY(-2px);
        }

        /* Footer */
        footer {
            background-color: var(--text-color);
            color: rgba(255, 255, 255, 0.7);
            padding: var(--spacing-lg) 0;
            margin-top: auto; /* Push footer to bottom */
        }

        .footer-content {
            text-align: center;
        }

        .footer-brand {
            font-size: 1.5rem;
            font-weight: 700;
            color: #ffffff;
            text-decoration: none;
            margin-bottom: var(--spacing-sm);
            display: inline-block;
        }

        .footer-links {
            list-style: none;
            padding: 0;
            margin-bottom: var(--spacing-md);
        }

        .footer-links li {
            display: inline-block;
            margin: 0 var(--spacing-sm);
        }

        .footer-links a {
            color: rgba(255, 255, 255, 0.7);
            transition: var(--transition-fast);
        }

        .footer-links a:hover {
            color: #ffffff;
            text-decoration: underline;
        }

        .copyright {
            font-size: 0.9rem;
        }
        .copyright a {
            color: rgba(255, 255, 255, 0.7);
        }
        .copyright a:hover {
            color: #ffffff;
        }

        /* Responsive adjustments */
        @media (max-width: 992px) {
            h1 { font-size: 2.2rem; }
            h2 { font-size: 1.8rem; }
            .hero h1 { font-size: 3rem; }
            .hero p { font-size: 1.1rem; }
            .content-block, .content-block-text, .content-block-image {
                flex-basis: 100%;
            }
        }

        @media (max-width: 768px) {
            .hero h1 { font-size: 2.5rem; }
            .hero p { font-size: 1rem; }
            .section-title { font-size: 2rem; }
            .content-block, .content-block-image {
                text-align: center;
            }
            .content-block-image img {
                max-width: 350px;
                margin: 0 auto;
            }
        }

        @media (max-width: 576px) {
            h1 { font-size: 2rem; }
            h2 { font-size: 1.6rem; }
            .hero h1 { font-size: 2rem; }
            .hero p { font-size: 0.95rem; }
            .cta-button, .cta-section .cta-button {
                padding: var(--spacing-sm) var(--spacing-lg);
                font-size: 1rem;
            }
            .footer-links li {
                display: block;
                margin: var(--spacing-xs) 0;
            }
        }

/* roulang page: article */
body{font-family:"Microsoft YaHei",system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.7;color:#1f2937;background:#f7f9fc}
  header,footer{background:#0f172a;color:#fff} header a,footer a{color:inherit;text-decoration:none}
  main section{padding:64px 0} .container{max-width:1180px}
  .hero,.site-hero{background:linear-gradient(135deg,#0f172a,#1d4ed8);color:#fff}
  .card,.feature-card,.service-card,.category-card{border:1px solid rgba(15,23,42,.08);box-shadow:0 12px 32px rgba(15,23,42,.08);border-radius:16px}
  .btn,.button,a[class*="btn"]{border-radius:999px;font-weight:700}
  img{max-width:100%;height:auto} @media(max-width:768px){main section{padding:42px 0} h1{font-size:2rem}}

/* roulang page: category1 */
:root {
            --primary-color: #d40d30; /* 鲜艳的红色 */
            --secondary-color: #2c3e50; /* 深邃的蓝色 */
            --accent-color: #e67e22; /* 暖橙色 */
            --background-color: #ffffff;
            --text-color: #333333;
            --light-text-color: #777777;
            --border-color: #eeeeee;
            --card-background: #f9f9f9;
            --footer-background: #2c3e50;
            --footer-text-color: #ffffff;
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --container-padding: var(--spacing-unit);
            --section-padding: calc(var(--spacing-unit) * 3) 0;
            --header-height: 80px;
            --footer-height: 100px;
            --border-radius: 8px;
            --box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            --hover-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
            --transition-speed: 0.3s;
        }

        /* Reset & Base Styles */
        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
            font-size: 16px; /* Base font size */
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background-color: var(--background-color);
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        .container {
            width: 100%;
            max-width: var(--container-max-width);
            margin: 0 auto;
            padding: var(--container-padding);
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        a {
            color: var(--primary-color);
            text-decoration: none;
            transition: color var(--transition-speed) ease;
        }

        a:hover, a:focus {
            color: var(--accent-color);
            text-decoration: underline;
        }

        h1, h2, h3, h4, h5, h6 {
            margin-bottom: var(--spacing-unit);
            line-height: 1.3;
            font-weight: 700;
        }

        h1 { font-size: 2.5rem; }
        h2 { font-size: 2rem; }
        h3 { font-size: 1.75rem; }
        h4 { font-size: 1.5rem; }
        h5 { font-size: 1.25rem; }
        h6 { font-size: 1rem; }

        p {
            margin-bottom: var(--spacing-unit);
        }

        button {
            cursor: pointer;
            border: none;
            background: none;
            font-family: inherit;
        }

        /* Header & Navigation */
        header {
            background-color: var(--background-color);
            padding: calc(var(--spacing-unit) * 0.5) 0;
            border-bottom: 1px solid var(--border-color);
            position: sticky;
            top: 0;
            z-index: 1000;
            height: var(--header-height);
            display: flex;
            align-items: center;
        }

        header .container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--secondary-color);
            letter-spacing: -0.5px;
        }

        .logo:hover {
            text-decoration: none;
            color: var(--primary-color);
        }

        nav ul.nav-links {
            list-style: none;
            display: flex;
            gap: calc(var(--spacing-unit) * 2);
        }

        nav ul.nav-links li a {
            font-size: 1.1rem;
            font-weight: 500;
            color: var(--text-color);
            padding: 0.5rem 0;
            position: relative;
            transition: color var(--transition-speed) ease;
        }

        nav ul.nav-links li a.active {
            color: var(--primary-color);
            font-weight: 700;
        }

        nav ul.nav-links li a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background-color: var(--primary-color);
            transform: scaleX(0);
            transform-origin: bottom right;
            transition: transform var(--transition-speed) ease-out;
        }

        nav ul.nav-links li a:hover::after,
        nav ul.nav-links li a:focus::after {
            transform: scaleX(1);
            transform-origin: bottom left;
        }
        
        .mobile-nav-toggle {
            display: none;
            font-size: 2rem;
            background: none;
            border: none;
            color: var(--text-color);
        }

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            color: #ffffff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 5) 0;
            position: relative;
            overflow: hidden;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.5);
            z-index: 1;
        }

        .hero .container {
            position: relative;
            z-index: 2;
        }

        .hero h1 {
            font-size: 3rem;
            margin-bottom: var(--spacing-unit);
            text-shadow: 2px 2px 8px rgba(0,0,0,0.7);
        }

        .hero p {
            font-size: 1.25rem;
            max-width: 800px;
            margin: 0 auto var(--spacing-unit);
            text-shadow: 1px 1px 5px rgba(0,0,0,0.7);
        }

        .hero .cta-button {
            display: inline-block;
            background-color: var(--primary-color);
            color: #ffffff;
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
            border-radius: var(--border-radius);
            font-size: 1.2rem;
            font-weight: 700;
            transition: background-color var(--transition-speed) ease, transform var(--transition-speed) ease;
            box-shadow: var(--box-shadow);
        }

        .hero .cta-button:hover,
        .hero .cta-button:focus {
            background-color: var(--accent-color);
            transform: translateY(-3px);
            box-shadow: var(--hover-shadow);
            text-decoration: none;
        }

        /* Content Sections */
        .content-section {
            padding: var(--section-padding);
        }

        .content-section h2 {
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 2);
            color: var(--secondary-color);
        }

        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: calc(var(--spacing-unit) * 2);
        }

        .card {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            overflow: hidden;
            transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
            display: flex;
            flex-direction: column;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: var(--hover-shadow);
        }

        .card img {
            width: 100%;
            height: 200px; /* Fixed height for consistent look */
            object-fit: cover;
            border-bottom: 1px solid var(--border-color);
        }

        .card .card-content {
            padding: var(--spacing-unit);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }

        .card h3 {
            font-size: 1.3rem;
            margin-bottom: var(--spacing-unit);
            color: var(--secondary-color);
        }

        .card p {
            font-size: 0.95rem;
            color: var(--light-text-color);
            flex-grow: 1;
        }

        .card .card-link {
            display: inline-block;
            margin-top: var(--spacing-unit);
            font-weight: 600;
            color: var(--primary-color);
            transition: color var(--transition-speed) ease;
        }

        .card .card-link:hover {
            color: var(--accent-color);
            text-decoration: none;
        }

        /* Feature Section */
        .feature-section {
            background-color: var(--card-background);
        }

        .feature-section .container {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: calc(var(--spacing-unit) * 2);
        }

        .feature-section .feature-text {
            flex: 1;
            min-width: 300px;
        }

        .feature-section .feature-image {
            flex: 1;
            min-width: 300px;
            text-align: center;
        }

        .feature-section .feature-image img {
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }

        .feature-section h2 {
            text-align: left;
            color: var(--secondary-color);
        }

        .feature-section ul {
            list-style: disc;
            margin-left: calc(var(--spacing-unit) * 2);
            color: var(--light-text-color);
        }

        .feature-section li {
            margin-bottom: var(--spacing-unit);
        }

        /* FAQ Section */
        .faq-section {
            background-color: #fefefe;
        }

        .faq-section .faq-item {
            margin-bottom: var(--spacing-unit);
            border: 1px solid var(--border-color);
            border-radius: var(--border-radius);
            overflow: hidden;
        }

        .faq-section .faq-question {
            background-color: var(--card-background);
            padding: var(--spacing-unit);
            font-weight: 600;
            cursor: pointer;
            position: relative;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: background-color var(--transition-speed) ease;
        }

        .faq-section .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            transition: transform var(--transition-speed) ease;
        }

        .faq-section .faq-item.open .faq-question::after {
            transform: rotate(45deg);
        }

        .faq-section .faq-answer {
            padding: var(--spacing-unit);
            max-height: 0;
            overflow: hidden;
            transition: max-height var(--transition-speed) ease-out, padding var(--transition-speed) ease-out;
            background-color: var(--background-color);
        }

        .faq-section .faq-item.open .faq-answer {
            max-height: 200px; /* Adjust as needed */
            padding: var(--spacing-unit);
        }

        /* CTA Section */
        .cta-section {
            background-color: var(--secondary-color);
            color: #ffffff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 4) 0;
        }

        .cta-section h2 {
            color: #ffffff;
            margin-bottom: var(--spacing-unit);
            font-size: 2.2rem;
        }

        .cta-section p {
            font-size: 1.1rem;
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        .cta-section .cta-button {
            display: inline-block;
            background-color: var(--primary-color);
            color: #ffffff;
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 2.5);
            border-radius: var(--border-radius);
            font-size: 1.3rem;
            font-weight: 700;
            transition: background-color var(--transition-speed) ease, transform var(--transition-speed) ease;
        }

        .cta-section .cta-button:hover,
        .cta-section .cta-button:focus {
            background-color: var(--accent-color);
            transform: translateY(-3px);
            box-shadow: var(--hover-shadow);
            text-decoration: none;
        }

        /* Footer */
        footer {
            background-color: var(--footer-background);
            color: var(--footer-text-color);
            padding: calc(var(--spacing-unit) * 3) 0;
            margin-top: auto; /* Pushes footer to the bottom */
        }

        footer .container {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: calc(var(--spacing-unit) * 1.5);
        }

        .footer-brand {
            font-size: 2rem;
            font-weight: 700;
            color: #ffffff;
        }

        .footer-brand:hover {
            color: var(--accent-color);
            text-decoration: none;
        }

        .footer-links {
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: calc(var(--spacing-unit) * 2);
        }

        .footer-links li a {
            color: #ffffff;
            font-size: 1.1rem;
            transition: color var(--transition-speed) ease;
        }

        .footer-links li a:hover {
            color: var(--accent-color);
            text-decoration: underline;
        }

        .copyright {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            :root {
                --header-height: 70px;
            }
            h1 { font-size: 2.2rem; }
            h2 { font-size: 1.8rem; }
            .hero h1 { font-size: 2.5rem; }
            .hero p { font-size: 1.1rem; }

            .feature-section .container,
            .card-grid {
                grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            }
        }

        @media (max-width: 768px) {
            :root {
                --header-height: 60px;
            }
            nav ul.nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: var(--header-height);
                left: 0;
                width: 100%;
                background-color: var(--background-color);
                padding: var(--spacing-unit) 0;
                box-shadow: 0 4px 10px rgba(0,0,0,0.1);
            }
            
            nav ul.nav-links.active {
                display: flex;
            }

            nav ul.nav-links li {
                text-align: center;
                padding: var(--spacing-unit);
            }

            nav ul.nav-links li a {
                display: block;
                width: 100%;
            }

            .mobile-nav-toggle {
                display: block;
            }
            
            header .container {
                flex-wrap: wrap;
            }
            
            .logo {
                flex-basis: 100%;
                text-align: center;
                margin-bottom: 0.5rem;
            }

            .hero {
                padding: calc(var(--spacing-unit) * 4) 0;
            }

            .hero h1 {
                font-size: 2.2rem;
            }

            .hero p {
                font-size: 1rem;
            }

            .cta-section {
                padding: calc(var(--spacing-unit) * 3) 0;
            }

            .cta-section h2 {
                font-size: 1.8rem;
            }
            
            .footer-links {
                flex-direction: column;
                text-align: center;
            }
            
            .feature-section .container {
                flex-direction: column;
            }
            .feature-section .feature-text,
            .feature-section .feature-image {
                width: 100%;
            }
            .card-grid {
                grid-template-columns: 1fr;
            }
        }

/* roulang page: category2 */
:root {
            --primary-color: #ff6b6b;
            --secondary-color: #48dbfb;
            --accent-color: #feca57;
            --background-color: #f8f9fa;
            --text-color: #333;
            --text-muted-color: #666;
            --border-color: #e0e0e0;
            --card-background: #fff;
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --border-radius: 8px;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
            --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
            --font-family: 'Helvetica Neue', Arial, sans-serif;
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: var(--font-family);
            line-height: 1.6;
            color: var(--text-color);
            background-color: var(--background-color);
            scroll-behavior: smooth;
        }

        .container {
            max-width: var(--container-max-width);
            margin: 0 auto;
            padding: 0 var(--spacing-unit);
        }

        a {
            color: var(--primary-color);
            text-decoration: none;
            transition: color 0.3s ease;
        }

        a:hover {
            color: #ff4757;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        /* Header & Navigation */
        header {
            background-color: #fff;
            box-shadow: var(--shadow-sm);
            padding: var(--spacing-unit) 0;
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: bold;
            color: var(--text-color);
        }

        .nav-links {
            list-style: none;
            display: flex;
            gap: calc(var(--spacing-unit) * 2);
        }

        .nav-links a {
            color: var(--text-color);
            font-weight: 500;
            padding: 0.5rem 0;
            position: relative;
        }

        .nav-links a.active {
            color: var(--primary-color);
            font-weight: bold;
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: var(--primary-color);
            transition: width 0.3s ease;
        }

        .nav-links a:hover::after {
            width: 100%;
        }

        .mobile-nav-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.8rem;
            cursor: pointer;
            color: var(--text-color);
        }

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            color: #fff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 8) var(--spacing-unit);
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 50vh;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.5);
        }

        .hero-content {
            position: relative;
            z-index: 1;
            max-width: 800px;
        }

        .hero h1 {
            font-size: 3rem;
            margin-bottom: calc(var(--spacing-unit) * 1.5);
            line-height: 1.2;
        }

        .hero p {
            font-size: 1.2rem;
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: var(--text-color);
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            font-size: 1.1rem;
            font-weight: bold;
            transition: transform 0.3s ease, background-color 0.3s ease;
            box-shadow: var(--shadow-md);
        }

        .cta-button:hover {
            transform: translateY(-3px);
            background-color: var(--primary-color);
            color: #fff;
        }

        /* Section Styling */
        .section {
            padding: calc(var(--spacing-unit) * 6) 0;
        }

        .section h2 {
            font-size: 2.5rem;
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 4);
            position: relative;
        }

        .section h2::after {
            content: '';
            position: absolute;
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 4px;
            background-color: var(--secondary-color);
            border-radius: 2px;
        }

        /* Content Cards */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: calc(var(--spacing-unit) * 3);
        }

        .card {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow-md);
            overflow: hidden;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 12px rgba(0, 0, 0, 0.15);
        }

        .card img {
            width: 100%;
            height: 200px;
            object-fit: cover;
        }

        .card-content {
            padding: calc(var(--spacing-unit) * 2);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .card-title {
            font-size: 1.4rem;
            margin-bottom: var(--spacing-unit);
            color: var(--text-color);
        }

        .card-description {
            font-size: 0.95rem;
            color: var(--text-muted-color);
            margin-bottom: var(--spacing-unit) * 1.5;
        }

        .card-link {
            display: inline-block;
            font-weight: bold;
            color: var(--primary-color);
            margin-top: auto;
        }

        /* Feature Section */
        .feature {
            background-color: #fff;
            padding: calc(var(--spacing-unit) * 4) 0;
        }

        .feature-content {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: calc(var(--spacing-unit) * 5);
            align-items: center;
        }

        .feature-content.reverse {
            grid-template-columns: 1fr 1fr; /* Keep same columns for consistency */
        }

        .feature-content.reverse .feature-text {
            order: 1;
        }

        .feature-content.reverse .feature-image {
            order: 2;
        }

        .feature-text h3 {
            font-size: 2rem;
            margin-bottom: var(--spacing-unit) * 2;
        }

        .feature-text p {
            font-size: 1.05rem;
            color: var(--text-muted-color);
            margin-bottom: var(--spacing-unit) * 2;
        }
        
        .feature-text .cta-button {
            font-size: 1rem;
            padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
        }

        /* FAQ Section */
        .faq-section {
            background-color: var(--card-background);
            padding: calc(var(--spacing-unit) * 6) 0;
        }

        .faq-item {
            border-bottom: 1px solid var(--border-color);
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        .faq-item:last-child {
            border-bottom: none;
            margin-bottom: 0;
        }

        .faq-question {
            font-size: 1.2rem;
            font-weight: bold;
            color: var(--text-color);
            cursor: pointer;
            padding: var(--spacing-unit) 0;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            transition: transform 0.3s ease;
        }

        .faq-question.active::after {
            transform: rotate(45deg);
        }

        .faq-answer {
            font-size: 1rem;
            color: var(--text-muted-color);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out;
            padding-top: 0;
        }

        .faq-question.active + .faq-answer {
            max-height: 200px; /* Adjust as needed */
            padding-top: var(--spacing-unit);
        }

        /* CTA Section */
        .cta-section {
            background-color: var(--primary-color);
            color: #fff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 6) 0;
        }

        .cta-section h2 {
            font-size: 2.8rem;
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        .cta-section p {
            font-size: 1.1rem;
            margin-bottom: calc(var(--spacing-unit) * 4);
        }

        .cta-section .cta-button {
            background-color: var(--accent-color);
            color: var(--text-color);
            font-size: 1.2rem;
            padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 4);
        }

        .cta-section .cta-button:hover {
            background-color: #e0c84a;
            color: #fff;
        }

        /* Footer */
        footer {
            background-color: #333;
            color: #fff;
            padding: calc(var(--spacing-unit) * 4) 0;
            text-align: center;
        }

        .footer-brand {
            font-size: 1.8rem;
            font-weight: bold;
            color: #fff;
            margin-bottom: var(--spacing-unit) * 2;
            display: block;
        }

        .footer-links {
            list-style: none;
            display: flex;
            justify-content: center;
            gap: calc(var(--spacing-unit) * 2);
            margin-bottom: var(--spacing-unit) * 2;
            flex-wrap: wrap;
        }

        .footer-links a {
            color: #bbb;
            transition: color 0.3s ease;
        }

        .footer-links a:hover {
            color: #fff;
        }

        .copyright {
            font-size: 0.9rem;
            color: #aaa;
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            .nav-links {
                gap: calc(var(--spacing-unit) * 1.5);
            }

            .hero h1 {
                font-size: 2.5rem;
            }

            .section h2 {
                font-size: 2rem;
            }

            .feature-content {
                grid-template-columns: 1fr;
                gap: calc(var(--spacing-unit) * 3);
            }
            
            .feature-content.reverse .feature-text,
            .feature-content.reverse .feature-image {
                order: unset; /* Reset order for single column layout */
            }

            .cta-section h2 {
                font-size: 2.2rem;
            }
        }

        @media (max-width: 768px) {
            .mobile-nav-toggle {
                display: block;
            }

            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 80px; /* Adjust based on header height */
                left: 0;
                width: 100%;
                background-color: #fff;
                box-shadow: var(--shadow-md);
                padding: var(--spacing-unit) 0;
                text-align: center;
            }

            .nav-links.active {
                display: flex;
            }

            .nav-links li {
                margin: var(--spacing-unit) 0;
            }

            .hero {
                padding: calc(var(--spacing-unit) * 6) var(--spacing-unit);
                min-height: 40vh;
            }

            .hero h1 {
                font-size: 2rem;
            }

            .hero p {
                font-size: 1rem;
            }

            .cta-button {
                font-size: 1rem;
                padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
            }

            .card-grid {
                grid-template-columns: 1fr;
            }

            .footer-links {
                flex-direction: column;
                gap: var(--spacing-unit);
            }
        }

/* roulang page: category3 */
:root {
            --primary-color: #ff6b6b;
            --secondary-color: #f0f0f0;
            --background-color: #ffffff;
            --text-color: #333333;
            --weak-text-color: #777777;
            --border-color: #dddddd;
            --card-background: #ffffff;
            --hover-color: #e55b5b;
            --focus-outline-color: rgba(255, 107, 107, 0.5);
            --border-radius: 8px;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            --container-max-width: 1200px;
            --spacing-unit: 16px;
            --nav-height: 70px;
            --footer-height: 100px;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background-color: var(--background-color);
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        .container {
            max-width: var(--container-max-width);
            margin: 0 auto;
            padding: 0 var(--spacing-unit);
            width: 100%;
        }

        header {
            background-color: var(--background-color);
            box-shadow: var(--shadow);
            height: var(--nav-height);
            display: flex;
            align-items: center;
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
        }

        .logo {
            font-size: 1.8em;
            font-weight: 700;
            color: var(--primary-color);
            text-decoration: none;
            letter-spacing: -1px;
        }

        .nav-links {
            list-style: none;
            display: flex;
            gap: var(--spacing-unit) * 2;
        }

        .nav-links li a {
            color: var(--text-color);
            text-decoration: none;
            font-weight: 500;
            padding: var(--spacing-unit) 0;
            transition: color 0.3s ease;
        }

        .nav-links li a:hover,
        .nav-links li a.active {
            color: var(--primary-color);
        }

        .mobile-nav-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 2em;
            cursor: pointer;
            color: var(--text-color);
        }

        main {
            flex: 1;
            padding: var(--spacing-unit) 0;
        }

        .hero-section {
            background-image: url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
            color: white;
            text-align: center;
            padding: var(--spacing-unit) * 8 var(--spacing-unit);
            min-height: 400px;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
            border-radius: var(--border-radius);
            margin-bottom: var(--spacing-unit) * 4;
        }

        .hero-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.5);
            border-radius: var(--border-radius);
        }

        .hero-content {
            position: relative;
            z-index: 1;
        }

        .hero-content h1 {
            font-size: 3em;
            margin-bottom: var(--spacing-unit);
            line-height: 1.2;
            letter-spacing: -1px;
        }

        .hero-content p {
            font-size: 1.3em;
            margin-bottom: var(--spacing-unit) * 3;
            color: var(--secondary-color);
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
        }

        .btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: white;
            padding: var(--spacing-unit) * 1.5 var(--spacing-unit) * 3;
            text-decoration: none;
            border-radius: var(--border-radius);
            font-weight: 600;
            font-size: 1.1em;
            transition: background-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
            border: none;
            cursor: pointer;
        }

        .btn:hover {
            background-color: var(--hover-color);
            transform: translateY(-2px);
            box-shadow: var(--shadow);
        }

        .btn:focus {
            outline: none;
            box-shadow: 0 0 0 3px var(--focus-outline-color);
        }

        .section {
            margin-bottom: var(--spacing-unit) * 6;
        }

        .section-title {
            text-align: center;
            font-size: 2.5em;
            margin-bottom: var(--spacing-unit) * 4;
            font-weight: 700;
            letter-spacing: -0.5px;
        }

        .content-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: var(--spacing-unit) * 3;
        }

        .card {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            overflow: hidden;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
        }

        .card img {
            width: 100%;
            height: 220px;
            object-fit: cover;
            display: block;
        }

        .card-content {
            padding: var(--spacing-unit) * 2;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }

        .card-content h3 {
            font-size: 1.5em;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
            line-height: 1.3;
        }

        .card-content p {
            font-size: 0.95em;
            color: var(--weak-text-color);
            flex-grow: 1;
            margin-bottom: var(--spacing-unit) * 2;
        }

        .card-content .btn {
            background-color: var(--text-color);
            padding: var(--spacing-unit) * 1 var(--spacing-unit) * 2;
            font-size: 1em;
            align-self: flex-start;
        }

        .card-content .btn:hover {
            background-color: var(--hover-color);
        }

        .feature-section {
            background-color: var(--secondary-color);
            padding: var(--spacing-unit) * 6 0;
        }

        .feature-list {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--spacing-unit) * 4;
            text-align: center;
        }

        .feature-item {
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        .feature-icon {
            font-size: 3em;
            color: var(--primary-color);
            margin-bottom: var(--spacing-unit) * 2;
        }

        .feature-item h4 {
            font-size: 1.3em;
            margin-bottom: var(--spacing-unit);
            color: var(--text-color);
        }

        .feature-item p {
            font-size: 0.95em;
            color: var(--weak-text-color);
        }

        .faq-section {
            padding: var(--spacing-unit) * 6 0;
        }

        .faq-list {
            max-width: 800px;
            margin: 0 auto;
        }

        .faq-item {
            border-bottom: 1px solid var(--border-color);
            padding: var(--spacing-unit) * 2 0;
        }

        .faq-question {
            font-size: 1.2em;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: color 0.3s ease;
        }

        .faq-question:hover {
            color: var(--primary-color);
        }

        .faq-question::after {
            content: '+';
            font-size: 1.5em;
            transition: transform 0.3s ease;
        }

        .faq-item.open .faq-question::after {
            transform: rotate(45deg);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out, padding 0.3s ease-out;
            font-size: 0.95em;
            color: var(--weak-text-color);
            padding-top: 0;
        }

        .faq-item.open .faq-answer {
            max-height: 200px; /* Adjust as needed */
            padding-top: var(--spacing-unit);
        }

        .cta-section {
            background-color: var(--primary-color);
            color: white;
            text-align: center;
            padding: var(--spacing-unit) * 6 0;
            border-radius: var(--border-radius);
            margin-top: var(--spacing-unit) * 4;
        }

        .cta-section h2 {
            font-size: 2.8em;
            margin-bottom: var(--spacing-unit) * 2;
            line-height: 1.2;
        }

        .cta-section p {
            font-size: 1.2em;
            margin-bottom: var(--spacing-unit) * 3;
            color: var(--secondary-color);
        }

        footer {
            background-color: var(--text-color);
            color: var(--secondary-color);
            padding: var(--spacing-unit) * 4 0;
            margin-top: auto; /* Pushes footer to the bottom */
            height: var(--footer-height);
            display: flex;
            align-items: center;
        }

        .footer-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
        }

        .footer-brand {
            font-size: 1.8em;
            font-weight: 700;
            color: white;
            text-decoration: none;
        }

        .footer-links {
            list-style: none;
            display: flex;
            gap: var(--spacing-unit) * 2;
        }

        .footer-links li a {
            color: var(--secondary-color);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s ease;
        }

        .footer-links li a:hover {
            color: var(--primary-color);
        }

        .copyright {
            font-size: 0.9em;
            color: var(--weak-text-color);
        }

        @media (max-width: 768px) {
            .logo {
                font-size: 1.5em;
            }

            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: var(--nav-height);
                left: 0;
                right: 0;
                background-color: var(--background-color);
                box-shadow: var(--shadow);
                padding: var(--spacing-unit) * 2;
                gap: var(--spacing-unit);
            }

            .nav-links.open {
                display: flex;
            }

            .nav-links li {
                width: 100%;
                text-align: center;
            }

            .mobile-nav-toggle {
                display: block;
            }

            .hero-content h1 {
                font-size: 2.5em;
            }

            .hero-content p {
                font-size: 1.1em;
            }

            .section-title {
                font-size: 2em;
            }

            .feature-list {
                grid-template-columns: 1fr;
            }

            .footer-content {
                flex-direction: column;
                text-align: center;
                gap: var(--spacing-unit) * 2;
            }

            .footer-links {
                flex-direction: column;
            }
        }

        @media (max-width: 520px) {
            .hero-content h1 {
                font-size: 2em;
            }

            .hero-section {
                min-height: 300px;
            }

            .card img {
                height: 180px;
            }

            .cta-section h2 {
                font-size: 2em;
            }
        }

/* roulang page: category4 */
:root {
            --primary-color: #ff6b6b; /* 主题红色 */
            --secondary-color: #48dbfb; /* 辅助蓝色 */
            --accent-color: #2ed573; /* 强调绿色 */
            --background-color: #f7f1e3; /* 浅米色背景 */
            --text-color: #333; /* 深灰色文字 */
            --light-text-color: #666; /* 浅灰色文字 */
            --border-color: #ccc; /* 边框灰色 */
            --card-background: #ffffff; /* 卡片白色背景 */
            --button-hover-bg: #e05252; /* 按钮悬停背景 */
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --font-family: 'Helvetica Neue', Arial, sans-serif;
            --border-radius: 8px;
            --box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            --header-height: 70px;
            --footer-height: 100px;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: var(--font-family);
            background-color: var(--background-color);
            color: var(--text-color);
            line-height: 1.6;
            scroll-behavior: smooth;
        }

        .container {
            max-width: var(--container-max-width);
            margin: 0 auto;
            padding: 0 calc(var(--spacing-unit) * 1.5);
        }

        a {
            color: var(--primary-color);
            text-decoration: none;
            transition: color 0.3s ease;
        }

        a:hover {
            color: var(--button-hover-bg);
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        /* Header */
        header {
            background-color: var(--card-background);
            padding: var(--spacing-unit) 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: bold;
            color: var(--primary-color);
        }

        .nav-links {
            list-style: none;
            display: flex;
            gap: var(--spacing-unit) * 2;
        }

        .nav-links li a {
            color: var(--text-color);
            font-weight: 500;
            padding: calc(var(--spacing-unit) / 2) calc(var(--spacing-unit));
            border-radius: var(--border-radius);
            transition: background-color 0.3s ease, color 0.3s ease;
        }

        .nav-links li a:hover,
        .nav-links li a.active {
            background-color: var(--primary-color);
            color: #fff;
        }

        .mobile-nav-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 2rem;
            cursor: pointer;
            color: var(--text-color);
        }

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-3.webp'); /* 替换为合适的背景图 */
            background-size: cover;
            background-position: center;
            color: #fff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 8) 0;
            position: relative;
            display: flex;
            justify-content: center;
            align-items: center;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.5);
            z-index: 1;
        }

        .hero .container {
            position: relative;
            z-index: 2;
        }

        .hero h1 {
            font-size: 3rem;
            margin-bottom: var(--spacing-unit);
        }

        .hero p {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-unit) * 2;
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
        }

        .hero .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: #fff;
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            font-weight: bold;
            font-size: 1.1rem;
            transition: background-color 0.3s ease, transform 0.3s ease;
        }

        .hero .cta-button:hover {
            background-color: var(--button-hover-bg);
            transform: translateY(-3px);
        }

        /* Main Content Area */
        main {
            padding: calc(var(--spacing-unit) * 4) 0;
        }

        .section-title {
            text-align: center;
            font-size: 2.5rem;
            margin-bottom: calc(var(--spacing-unit) * 3);
            color: var(--primary-color);
        }

        /* Category Showcase */
        .category-showcase {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: calc(var(--spacing-unit) * 2);
        }

        .category-card {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            overflow: hidden;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .category-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
        }

        .category-card img {
            width: 100%;
            height: 200px; /* Fixed height for consistent look */
            object-fit: cover;
        }

        .category-card .card-content {
            padding: calc(var(--spacing-unit) * 2);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .category-card h3 {
            font-size: 1.6rem;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
        }

        .category-card p {
            font-size: 0.95rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-unit) * 1.5;
        }

        .category-card .category-link {
            display: inline-block;
            background-color: var(--secondary-color);
            color: #fff;
            padding: calc(var(--spacing-unit) * 0.8) calc(var(--spacing-unit) * 1.5);
            border-radius: var(--border-radius);
            font-weight: bold;
            transition: background-color 0.3s ease;
            text-align: center;
        }

        .category-card .category-link:hover {
            background-color: #3aace0;
        }

        /* Feature Section */
        .feature-section {
            background-color: #fff;
            padding: calc(var(--spacing-unit) * 5) 0;
        }

        .feature-section .container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: calc(var(--spacing-unit) * 4);
            align-items: center;
        }

        .feature-section .feature-text h2 {
            font-size: 2.2rem;
            margin-bottom: var(--spacing-unit) * 2;
            color: var(--primary-color);
        }

        .feature-section .feature-text p {
            font-size: 1.1rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-unit);
        }
        .feature-section .feature-image img {
             border-radius: var(--border-radius);
             box-shadow: var(--box-shadow);
        }


        /* FAQ Section */
        .faq-section {
            padding: calc(var(--spacing-unit) * 5) 0;
        }

        .faq-list {
            list-style: none;
            display: grid;
            grid-template-columns: 1fr;
            gap: var(--spacing-unit);
        }

        .faq-item {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            padding: calc(var(--spacing-unit) * 1.5);
            cursor: pointer;
        }

        .faq-item .question {
            font-weight: bold;
            font-size: 1.2rem;
            color: var(--primary-color);
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: color 0.3s ease;
        }

        .faq-item .question:hover {
            color: var(--button-hover-bg);
        }

        .faq-item .question::after {
            content: '+';
            font-size: 1.5rem;
            transition: transform 0.3s ease;
        }

        .faq-item.open .question::after {
            content: '-';
            transform: rotate(180deg);
        }

        .faq-item .answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out, padding 0.3s ease-out;
            padding-top: 0;
            font-size: 1rem;
            color: var(--light-text-color);
            margin-top: var(--spacing-unit) * 1.5;
        }

        .faq-item.open .answer {
            max-height: 200px; /* Adjust as needed */
            padding-top: calc(var(--spacing-unit) * 1.5);
        }

        /* CTA Section */
        .cta-section {
            background-color: var(--primary-color);
            color: #fff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 5) 0;
        }

        .cta-section h2 {
            font-size: 2.8rem;
            margin-bottom: var(--spacing-unit) * 1.5;
        }

        .cta-section p {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-unit) * 3;
        }

        .cta-section .cta-button {
            display: inline-block;
            background-color: #fff;
            color: var(--primary-color);
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            font-weight: bold;
            font-size: 1.1rem;
            transition: background-color 0.3s ease, color 0.3s ease;
        }

        .cta-section .cta-button:hover {
            background-color: #eee;
            color: var(--button-hover-bg);
        }

        /* Footer */
        footer {
            background-color: #333;
            color: #ccc;
            padding: calc(var(--spacing-unit) * 3) 0;
            text-align: center;
            font-size: 0.9rem;
        }

        footer .footer-brand {
            font-size: 1.8rem;
            font-weight: bold;
            color: #fff;
            margin-bottom: var(--spacing-unit) * 2;
            display: block;
        }

        .footer-links {
            list-style: none;
            display: flex;
            justify-content: center;
            gap: var(--spacing-unit) * 2;
            margin-bottom: var(--spacing-unit) * 2;
            flex-wrap: wrap;
        }

        .footer-links li a {
            color: #ccc;
            transition: color 0.3s ease;
        }

        .footer-links li a:hover {
            color: #fff;
        }

        .copyright {
            margin-top: var(--spacing-unit) * 2;
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: var(--header-height);
                left: 0;
                width: 100%;
                background-color: var(--card-background);
                box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
                padding: var(--spacing-unit);
            }

            .nav-links.open {
                display: flex;
            }

            .nav-links li {
                text-align: center;
                margin-bottom: var(--spacing-unit);
            }

            .nav-links li a {
                padding: var(--spacing-unit);
                display: block;
            }

            .mobile-nav-toggle {
                display: block;
            }

            .hero h1 {
                font-size: 2.5rem;
            }

            .hero p {
                font-size: 1rem;
            }

            .section-title {
                font-size: 2rem;
            }

            .feature-section .container {
                grid-template-columns: 1fr;
            }

            .feature-section .feature-text {
                order: 2; /* Text below image on mobile */
            }
            .feature-section .feature-image {
                order: 1; /* Image above text on mobile */
            }
        }

        @media (max-width: 520px) {
            .logo {
                font-size: 1.5rem;
            }

            .hero h1 {
                font-size: 2rem;
            }
            .hero p {
                font-size: 0.9rem;
            }
            .hero .cta-button {
                padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
                font-size: 1rem;
            }
             .category-showcase {
                grid-template-columns: 1fr;
            }
            .cta-section h2 {
                font-size: 2rem;
            }
            .cta-section p {
                font-size: 1rem;
            }
            .footer-links {
                flex-direction: column;
                gap: var(--spacing-unit);
            }
        }