/* roulang page: index */
:root {
            --primary-color: #007bff;
            --secondary-color: #6c757d;
            --background-color: #ffffff;
            --text-color: #333333;
            --light-text-color: #666666;
            --border-color: #dee2e6;
            --card-background: #f8f9fa;
            --hover-color: #0056b3;
            --focus-outline-color: rgba(0, 123, 255, 0.5);
            --border-radius: 8px;
            --box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
            --container-max-width: 1200px;
            --spacing-unit: 16px;
            --section-padding: 60px 0;
        }

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

        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);
            overflow-x: hidden;
        }

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

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

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

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

        /* Header & Navigation */
        header {
            background-color: var(--background-color);
            box-shadow: var(--box-shadow);
            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(--primary-color);
        }
        .logo span {
             color: var(--text-color);
        }

        nav ul {
            list-style: none;
            display: flex;
        }

        nav ul li {
            margin-left: var(--spacing-unit) * 2;
        }

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

        nav ul li a:hover,
        nav ul li a.active {
            color: var(--primary-color);
            text-decoration: none;
        }

        nav ul li a:hover::after,
        nav ul li a.active::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background-color: var(--primary-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: var(--spacing-unit) * 8 0;
            position: relative;
        }

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

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

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

        .hero p {
            font-size: 1.3rem;
            margin-bottom: var(--spacing-unit) * 2;
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
        }

        .btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: #fff;
            padding: var(--spacing-unit) var(--spacing-unit) * 2;
            border-radius: var(--border-radius);
            font-size: 1.1rem;
            font-weight: bold;
            transition: background-color 0.3s ease, transform 0.3s ease;
            border: none;
            cursor: pointer;
        }

        .btn:hover {
            background-color: var(--hover-color);
            color: #fff;
            text-decoration: none;
            transform: translateY(-2px);
        }

        .btn:focus {
            outline: 2px solid var(--focus-outline-color);
            outline-offset: 2px;
        }

        /* Section Title */
        .section-title {
            text-align: center;
            margin-bottom: var(--spacing-unit) * 4;
        }

        .section-title h2 {
            font-size: 2.5rem;
            margin-bottom: var(--spacing-unit);
        }

        .section-title p {
            font-size: 1.1rem;
            color: var(--light-text-color);
            max-width: 700px;
            margin: 0 auto;
        }

        /* Categories Section */
        .categories {
            padding: var(--section-padding);
            background-color: var(--card-background);
        }

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

        .category-card {
            background-color: var(--background-color);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            overflow: hidden;
            text-align: center;
            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 16px rgba(0, 0, 0, 0.15);
        }

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

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

        .category-card-content h3 {
            font-size: 1.5rem;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
        }

        .category-card-content p {
            font-size: 1rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-unit) * 2;
        }

        /* Latest Updates Section */
        .latest-updates {
            padding: var(--section-padding);
        }

        .latest-updates .container ul {
            list-style: none;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: var(--spacing-unit) * 2;
        }

        .latest-updates .container li {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            padding: var(--spacing-unit) * 2;
            box-shadow: var(--box-shadow);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .latest-updates .container li:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
        }

        .latest-updates .container li .update-title {
            font-size: 1.2rem;
            font-weight: bold;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
            display: block;
        }
        .latest-updates .container li .update-title:hover {
            text-decoration: underline;
        }

        .latest-updates .container li .update-meta {
            font-size: 0.9rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-unit);
        }
        .latest-updates .container li .update-excerpt {
            font-size: 1rem;
            color: var(--light-text-color);
            flex-grow: 1;
            margin-bottom: var(--spacing-unit) * 1.5;
        }

        /* Features Section */
        .features {
            padding: var(--section-padding);
            background-color: var(--background-color);
        }

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

        .feature-item {
            padding: var(--spacing-unit) * 2;
        }

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

        .feature-item h3 {
            font-size: 1.4rem;
            margin-bottom: var(--spacing-unit);
        }

        .feature-item p {
            font-size: 1rem;
            color: var(--light-text-color);
        }

        /* FAQ Section */
        .faq {
            padding: var(--section-padding);
            background-color: var(--card-background);
        }

        .faq .container {
            max-width: 800px;
        }

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

        .faq-question {
            background-color: var(--background-color);
            padding: var(--spacing-unit) * 1.5 var(--spacing-unit) * 2;
            font-size: 1.2rem;
            font-weight: bold;
            cursor: pointer;
            position: relative;
            transition: color 0.3s ease;
        }

        .faq-question::after {
            content: '+';
            position: absolute;
            right: var(--spacing-unit) * 2;
            font-size: 1.5rem;
            transition: transform 0.3s ease;
        }

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

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

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.5s ease;
            background-color: var(--background-color);
            padding: 0 var(--spacing-unit) * 2;
            font-size: 1rem;
            color: var(--light-text-color);
        }

        .faq-item.active .faq-answer {
            padding: var(--spacing-unit) * 1.5 var(--spacing-unit) * 2;
            max-height: 200px; /* Adjust as needed */
        }

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

        .cta h2 {
            font-size: 2.5rem;
            margin-bottom: var(--spacing-unit);
        }

        .cta p {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-unit) * 2;
        }

        /* Footer */
        footer {
            background-color: var(--text-color);
            color: #fff;
            padding: var(--spacing-unit) * 4 0 var(--spacing-unit) * 2;
            text-align: center;
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: var(--spacing-unit) * 3;
            margin-bottom: var(--spacing-unit) * 3;
        }

        .footer-section h3 {
            font-size: 1.3rem;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
        }

        .footer-section p, .footer-section a {
            font-size: 1rem;
            color: rgba(255, 255, 255, 0.8);
        }

        .footer-section a:hover {
            color: #fff;
            text-decoration: underline;
        }

        .footer-bottom {
            padding-top: var(--spacing-unit);
            border-top: 1px solid rgba(255, 255, 255, 0.2);
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero p {
                font-size: 1.1rem;
            }
            .features .container {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 768px) {
            nav {
                flex-wrap: wrap;
                justify-content: center;
            }
            nav .logo {
                width: 100%;
                text-align: center;
                margin-bottom: var(--spacing-unit) * 1;
            }
            nav ul {
                width: 100%;
                justify-content: center;
                margin-top: var(--spacing-unit);
            }
            nav ul li {
                margin: 0 var(--spacing-unit);
            }
            .hero {
                padding: var(--spacing-unit) * 6 0;
            }
            .hero h1 {
                font-size: 2.2rem;
            }
            .section-title h2 {
                font-size: 2rem;
            }
            .features .container {
                grid-template-columns: 1fr;
            }
            .footer-content {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 576px) {
            .hero {
                padding: var(--spacing-unit) * 5 0;
            }
            .hero h1 {
                font-size: 1.8rem;
            }
            .hero p {
                font-size: 1rem;
            }
            .btn {
                padding: var(--spacing-unit) * 0.8 var(--spacing-unit) * 1.6;
                font-size: 1rem;
            }
            .section-title h2 {
                font-size: 1.8rem;
            }
            .section-title p {
                font-size: 1rem;
            }
            .categories .container,
            .latest-updates .container ul {
                grid-template-columns: 1fr;
            }
            .category-card img, .latest-updates .container li {
                height: 180px;
            }
            .faq-question::after {
                right: var(--spacing-unit);
            }
            .faq-item.active .faq-answer {
                padding-bottom: var(--spacing-unit) * 1.5;
            }
        }

/* roulang page: article */
:root {
            --primary-color: #e91e63; /* Pink */
            --secondary-color: #f50057; /* Deep Pink */
            --accent-color: #ff4081; /* Light Pink */
            --background-color: #121212; /* Dark Background */
            --surface-color: #1e1e1e; /* Slightly lighter dark */
            --text-color: #ffffff;
            --text-muted-color: #b0b0b0;
            --border-color: #333333;
            --card-bg: #2a2a2a;
            --button-hover-bg: rgba(255, 255, 255, 0.1);
            --button-active-bg: rgba(255, 255, 255, 0.2);
            --radius-sm: 4px;
            --radius-md: 8px;
            --radius-lg: 12px;
            --shadow-md: 0 4px 10px rgba(0, 0, 0, 0.3);
            --container-width: 1200px;
            --spacing-md: 20px;
            --spacing-lg: 40px;
        }

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

        body {
            font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
            background-color: var(--background-color);
            color: var(--text-color);
            line-height: 1.6;
            overflow-x: hidden;
        }

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

        a:hover {
            color: var(--secondary-color);
        }

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

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

        header {
            background-color: var(--surface-color);
            padding: var(--spacing-md) 0;
            border-bottom: 1px solid var(--border-color);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

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

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

        .logo span {
            color: var(--accent-color);
        }

        nav ul {
            list-style: none;
            display: flex;
        }

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

        nav ul li a {
            color: var(--text-color);
            font-weight: bold;
            padding: 8px 15px;
            border-radius: var(--radius-sm);
            transition: background-color 0.3s ease, color 0.3s ease;
        }

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

        /* Hero Section */
        .hero {
            background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            height: 70vh;
            display: flex;
            justify-content: center;
            align-items: center;
            text-align: center;
            position: relative;
            color: var(--text-color);
            margin-bottom: var(--spacing-lg);
        }

        .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: 2;
        }

        .hero h1 {
            font-size: 3.5em;
            margin-bottom: var(--spacing-md);
            color: var(--primary-color);
            text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.5);
        }

        .hero p {
            font-size: 1.3em;
            max-width: 800px;
            margin: 0 auto var(--spacing-lg);
            color: var(--text-muted-color);
            text-shadow: 1px 1px 5px rgba(0, 0, 0, 0.5);
        }

        /* Main Content Section */
        .content-section {
            padding: var(--spacing-lg) 0;
        }

        .content-section h2 {
            text-align: center;
            font-size: 2.5em;
            margin-bottom: var(--spacing-lg);
            color: var(--primary-color);
        }

        /* Article Specific Styles */
        .article-title {
            font-size: 2.8em;
            margin-bottom: var(--spacing-md);
            line-height: 1.2;
            text-align: center;
        }

        .article-meta {
            text-align: center;
            color: var(--text-muted-color);
            margin-bottom: var(--spacing-lg);
            font-size: 0.9em;
        }

        .article-meta span {
            margin: 0 10px;
        }

        .article-content {
            font-size: 1.1em;
            max-width: 800px;
            margin: 0 auto;
            background-color: var(--surface-color);
            padding: var(--spacing-lg);
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-md);
        }

        .article-content h3 {
            color: var(--primary-color);
            margin-top: var(--spacing-lg);
            margin-bottom: var(--spacing-md);
            font-size: 1.8em;
        }

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

        .article-content ul,
        .article-content ol {
            margin-left: var(--spacing-md);
            margin-bottom: var(--spacing-md);
        }

        .article-content li {
            margin-bottom: 8px;
        }

        .article-content strong {
            color: var(--accent-color);
        }

        .article-content a {
            font-weight: bold;
        }

        .not-found {
            text-align: center;
            padding: var(--spacing-lg) 0;
            font-size: 1.2em;
        }

        .not-found a {
            display: inline-block;
            margin-top: var(--spacing-md);
            padding: 12px 25px;
            background-color: var(--primary-color);
            color: var(--text-color);
            border-radius: var(--radius-md);
            font-weight: bold;
            transition: background-color 0.3s ease, transform 0.3s ease;
        }

        .not-found a:hover {
            background-color: var(--secondary-color);
            transform: translateY(-2px);
        }


        /* Footer */
        footer {
            background-color: var(--surface-color);
            color: var(--text-muted-color);
            padding: var(--spacing-lg) 0;
            border-top: 1px solid var(--border-color);
            font-size: 0.9em;
        }

        .footer-content {
            display: flex;
            justify-content: space-around;
            flex-wrap: wrap;
            margin-bottom: var(--spacing-lg);
        }

        .footer-section {
            flex: 1;
            min-width: 200px;
            margin: var(--spacing-md);
        }

        .footer-section h3 {
            color: var(--primary-color);
            margin-bottom: var(--spacing-md);
            font-size: 1.3em;
        }

        .footer-section ul {
            list-style: none;
            padding: 0;
        }

        .footer-section ul li {
            margin-bottom: 8px;
        }

        .footer-section ul li a {
            color: var(--text-muted-color);
        }

        .footer-section ul li a:hover {
            color: var(--accent-color);
        }

        .footer-bottom {
            text-align: center;
            padding-top: var(--spacing-md);
            border-top: 1px solid var(--border-color);
        }

        .footer-bottom a {
            color: var(--text-muted-color);
            margin: 0 10px;
        }

        .footer-bottom a:hover {
            color: var(--accent-color);
        }

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

            nav ul {
                flex-direction: column;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background-color: var(--surface-color);
                padding: var(--spacing-md);
                display: none; /* Hidden by default, shown by JS toggle */
            }

            nav ul.open {
                display: flex;
            }

            nav ul li {
                margin: 10px 0;
            }

            .hero h1 {
                font-size: 2.8em;
            }

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

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

            .article-title {
                font-size: 2.2em;
            }

            .article-content {
                padding: var(--spacing-md);
            }

            .footer-content {
                flex-direction: column;
                align-items: center;
            }

            .footer-section {
                margin: var(--spacing-md) 0;
                text-align: center;
            }
        }

/* roulang page: category1 */
:root {
            --primary-color: #e74c3c; /* 主色调 - 鲜艳的红色 */
            --secondary-color: #34495e; /* 辅色调 - 深灰蓝 */
            --accent-color: #f39c12; /* 强调色 - 橙黄色 */
            --background-color: #f8f9fa; /* 背景色 - 浅灰 */
            --text-color: #333; /* 主要文字颜色 */
            --light-text-color: #777; /* 次要文字颜色 */
            --border-color: #ddd; /* 边框颜色 */
            --card-background: #fff; /* 卡片背景 */
            --container-max-width: 1200px;
            --spacing-xs: 8px;
            --spacing-sm: 16px;
            --spacing-md: 24px;
            --spacing-lg: 32px;
            --spacing-xl: 48px;
            --border-radius: 8px;
            --shadow-sm: 0 2px 4px rgba(0,0,0,.08);
            --shadow-md: 0 4px 8px rgba(0,0,0,.12);
        }

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

        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            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: color 0.3s ease;
        }

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

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

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

        /* Header & Navigation */
        header {
            background-color: var(--secondary-color);
            color: #fff;
            padding: var(--spacing-sm) 0;
            box-shadow: var(--shadow-sm);
        }

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

        .logo {
            font-size: 1.8em;
            font-weight: bold;
            color: #fff;
            letter-spacing: 1px;
        }

        .logo span {
            color: var(--accent-color);
        }

        header nav ul {
            list-style: none;
            display: flex;
        }

        header nav ul li {
            margin-left: var(--spacing-lg);
        }

        header nav ul li a {
            color: #fff;
            font-weight: 500;
            padding: var(--spacing-sm) var(--spacing-md);
            border-radius: var(--border-radius);
            transition: background-color 0.3s ease, color 0.3s ease;
            display: inline-block;
        }

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

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-2.webp'); /* 使用分类页对应的背景图 */
            background-size: cover;
            background-position: center;
            color: #fff;
            text-align: center;
            padding: var(--spacing-xl) var(--spacing-md);
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 400px; /* 确保有足够高度 */
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.5); /* 半透明遮罩层 */
        }

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

        .hero h1 {
            font-size: 3em;
            margin-bottom: var(--spacing-sm);
            line-height: 1.2;
        }

        .hero p {
            font-size: 1.3em;
            margin-bottom: var(--spacing-lg);
            color: rgba(255, 255, 255, 0.9);
        }

        /* Main Content Sections */
        .section {
            padding: var(--spacing-xl) 0;
        }

        .section h2 {
            text-align: center;
            font-size: 2.5em;
            margin-bottom: var(--spacing-lg);
            color: var(--secondary-color);
        }

        /* Video Grid */
        .video-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: var(--spacing-lg);
        }

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

        .video-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 16px rgba(0,0,0,.2);
        }

        .video-card img {
            width: 100%;
            height: 200px; /* 固定卡片图片高度 */
            object-fit: cover; /* 保持图片比例填充 */
        }

        .video-card-content {
            padding: var(--spacing-md);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .video-card h3 {
            font-size: 1.3em;
            margin-bottom: var(--spacing-sm);
            color: var(--secondary-color);
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }

        .video-card p {
            font-size: 0.95em;
            color: var(--light-text-color);
            display: -webkit-box;
            -webkit-line-clamp: 3; /* 限制3行 */
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .video-card .tags {
            margin-top: var(--spacing-sm);
            display: flex;
            flex-wrap: wrap;
            gap: var(--spacing-xs);
        }

        .video-card .tag {
            background-color: var(--primary-color);
            color: #fff;
            padding: 4px 10px;
            border-radius: 4px;
            font-size: 0.8em;
            display: inline-block;
        }

        /* Call to Action */
        .cta {
            background-color: var(--secondary-color);
            color: #fff;
            text-align: center;
            padding: var(--spacing-xl) var(--spacing-md);
        }

        .cta h2 {
            color: #fff;
            font-size: 2.5em;
            margin-bottom: var(--spacing-md);
        }

        .cta p {
            font-size: 1.2em;
            margin-bottom: var(--spacing-lg);
            color: rgba(255, 255, 255, 0.9);
        }

        .cta .btn {
            display: inline-block;
            background-color: var(--accent-color);
            color: #fff;
            padding: var(--spacing-sm) var(--spacing-lg);
            border-radius: var(--border-radius);
            font-size: 1.1em;
            font-weight: bold;
            transition: background-color 0.3s ease, transform 0.3s ease;
        }

        .cta .btn:hover {
            background-color: #e67e22; /* 鼠标悬停时的颜色 */
            transform: translateY(-3px);
            text-decoration: none;
        }

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

        .faq-item {
            margin-bottom: var(--spacing-md);
            border: 1px solid var(--border-color);
            border-radius: var(--border-radius);
            overflow: hidden;
            transition: box-shadow 0.3s ease;
        }

        .faq-item:hover {
            box-shadow: var(--shadow-md);
        }

        .faq-question {
            background-color: var(--background-color);
            padding: var(--spacing-md);
            font-size: 1.1em;
            font-weight: bold;
            cursor: pointer;
            position: relative;
            transition: background-color 0.3s ease;
        }

        .faq-question::after {
            content: '+';
            position: absolute;
            right: var(--spacing-md);
            font-size: 1.5em;
            transition: transform 0.3s ease;
        }

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

        .faq-answer {
            padding: var(--spacing-md);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
            background-color: #fff;
        }

        .faq-item.active .faq-answer {
            max-height: 200px; /* 根据内容调整 */
            padding: var(--spacing-md);
        }

        /* Footer */
        footer {
            background-color: var(--secondary-color);
            color: rgba(255, 255, 255, 0.7);
            padding: var(--spacing-xl) 0 var(--spacing-sm);
            margin-top: auto; /* 确保 footer 始终在底部 */
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: var(--spacing-lg);
            margin-bottom: var(--spacing-lg);
        }

        .footer-section h3 {
            color: #fff;
            font-size: 1.4em;
            margin-bottom: var(--spacing-sm);
        }

        .footer-section ul {
            list-style: none;
        }

        .footer-section ul li {
            margin-bottom: var(--spacing-sm);
        }

        .footer-section ul li a {
            color: rgba(255, 255, 255, 0.7);
            transition: color 0.3s ease;
        }

        .footer-section ul li a:hover {
            color: #fff;
            text-decoration: underline;
        }

        .footer-bottom {
            text-align: center;
            padding-top: var(--spacing-md);
            border-top: 1px solid rgba(255, 255, 255, 0.2);
            font-size: 0.9em;
        }

        .footer-bottom a {
            color: rgba(255, 255, 255, 0.7);
        }

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

        /* Responsive Design */
        @media (max-width: 992px) {
            .container {
                padding: 0 var(--spacing-sm);
            }
            .hero h1 {
                font-size: 2.5em;
            }
            .hero p {
                font-size: 1.1em;
            }
            .section h2 {
                font-size: 2em;
            }
            .video-grid {
                grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
            }
            .footer-content {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 768px) {
            header nav ul {
                display: none; /* 隐藏桌面导航，实际应使用移动端汉堡菜单 */
            }
            .hero h1 {
                font-size: 2em;
            }
            .hero p {
                font-size: 1em;
            }
            .cta h2 {
                font-size: 2em;
            }
        }

        @media (max-width: 576px) {
            .hero {
                min-height: 300px;
            }
            .hero h1 {
                font-size: 1.8em;
            }
            .video-grid {
                grid-template-columns: 1fr;
            }
            .video-card img {
                height: 180px;
            }
            .cta p {
                font-size: 1em;
            }
            .cta .btn {
                padding: var(--spacing-sm) var(--spacing-md);
                font-size: 1em;
            }
        }

/* roulang page: category2 */
:root {
            --primary-color: #ff6b6b; /* 主题亮红色 */
            --secondary-color: #f08080; /* 辅助暖红色 */
            --background-color: #f8f8f8; /* 浅灰色背景 */
            --text-color: #333; /* 深灰色文字 */
            --weak-text-color: #666; /* 浅灰色弱化文字 */
            --border-color: #ddd; /* 浅灰色边框 */
            --card-bg: #ffffff; /* 白色卡片背景 */
            --container-width: 1200px;
            --gutter: 20px;
            --border-radius: 8px;
            --box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            --transition-speed: 0.3s;
        }

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

        body {
            font-family: 'Microsoft YaHei', 'PingFang SC', 'Hiragino Sans GB', 'Segoe UI', Tahoma, Arial, sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background-color: var(--background-color);
            scroll-behavior: smooth;
        }

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

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

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

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

        .container {
            max-width: var(--container-width);
            margin: 0 auto;
            padding: 0 calc(var(--gutter) / 2);
        }

        /* Header & Nav */
        header {
            background-color: var(--card-bg);
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
            padding: calc(var(--gutter) * 1.5) 0;
            position: sticky;
            top: 0;
            z-index: 1000;
        }

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

        .logo {
            font-size: 2em;
            font-weight: bold;
            color: var(--primary-color);
        }

        .logo span {
            color: var(--text-color);
        }

        nav ul {
            list-style: none;
            display: flex;
        }

        nav ul li {
            margin-left: calc(var(--gutter) * 2);
        }

        nav ul li a {
            font-size: 1.1em;
            font-weight: 600;
            color: var(--weak-text-color);
            padding: 0.5em 0;
            position: relative;
            transition: color var(--transition-speed) ease;
        }

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

        nav ul li a.active::after,
        nav ul li a:hover::after,
        nav ul li a:focus::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: -2px;
            width: 100%;
            height: 2px;
            background-color: var(--primary-color);
        }

        /* Hero Section */
        .hero {
            background-color: var(--secondary-color);
            background-image: linear-gradient(rgba(255, 107, 107, 0.8), rgba(240, 128, 128, 0.8)), url('/assets/images/backpic/back-2.webp');
            background-size: cover;
            background-position: center;
            color: #fff;
            padding: calc(var(--gutter) * 5) 0;
            text-align: center;
        }

        .hero h1 {
            font-size: 3em;
            margin-bottom: var(--gutter);
            line-height: 1.3;
        }

        .hero p {
            font-size: 1.3em;
            opacity: 0.9;
            margin-bottom: calc(var(--gutter) * 2);
        }

        .hero .cta-button {
            display: inline-block;
            background-color: #fff;
            color: var(--primary-color);
            padding: 1em 2.5em;
            font-size: 1.2em;
            font-weight: bold;
            border-radius: var(--border-radius);
            transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
            box-shadow: 0 5px 20px rgba(0,0,0,0.1);
        }

        .hero .cta-button:hover,
        .hero .cta-button:focus {
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            text-decoration: none;
        }

        /* Section Styling */
        .section {
            padding: calc(var(--gutter) * 4) 0;
        }

        .section h2 {
            text-align: center;
            font-size: 2.5em;
            margin-bottom: calc(var(--gutter) * 2);
            color: var(--text-color);
        }

        .section p.subtitle {
            text-align: center;
            font-size: 1.2em;
            color: var(--weak-text-color);
            max-width: 700px;
            margin: 0 auto calc(var(--gutter) * 2) auto;
        }

        /* Content Cards */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: calc(var(--gutter) * 2);
        }

        .card {
            background-color: var(--card-bg);
            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: 0 8px 25px rgba(0, 0, 0, 0.15);
        }

        .card img {
            width: 100%;
            height: 200px; /* Fixed height for consistent card appearance */
            object-fit: cover; /* Cover the area, cropping if necessary */
            display: block;
        }

        .card-content {
            padding: calc(var(--gutter) * 1.5);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }

        .card-title {
            font-size: 1.4em;
            font-weight: bold;
            margin-bottom: var(--gutter);
            color: var(--text-color);
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .card-description {
            font-size: 0.95em;
            color: var(--weak-text-color);
            flex-grow: 1;
            margin-bottom: var(--gutter);
            display: -webkit-box;
            -webkit-line-clamp: 3;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .card-link {
            display: inline-block;
            margin-top: auto; /* Push link to the bottom */
            font-weight: 600;
            color: var(--primary-color);
            transition: color var(--transition-speed) ease;
        }

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

        /* Feature Section */
        .features-section .feature-item {
            display: flex;
            align-items: center;
            gap: var(--gutter);
            margin-bottom: calc(var(--gutter) * 2);
            padding: var(--gutter);
            background-color: var(--card-bg);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }

        .features-section .feature-item:hover {
            box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
        }

        .features-section .feature-icon {
            flex-shrink: 0;
            font-size: 2em;
            color: var(--primary-color);
            width: 50px;
            text-align: center;
        }

        .features-section .feature-content h3 {
            font-size: 1.4em;
            margin-bottom: calc(var(--gutter) / 2);
            color: var(--text-color);
        }

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

        /* FAQ Section */
        .faq-section .faq-item {
            margin-bottom: var(--gutter);
            border: 1px solid var(--border-color);
            border-radius: var(--border-radius);
            background-color: var(--card-bg);
        }

        .faq-section .faq-question {
            padding: 1em 1.5em;
            font-weight: bold;
            cursor: pointer;
            position: relative;
            background-color: var(--card-bg);
            border-radius: var(--border-radius);
            transition: background-color var(--transition-speed) ease;
        }

        .faq-section .faq-question::after {
            content: '+';
            position: absolute;
            right: 1.5em;
            font-size: 1.3em;
            transition: transform var(--transition-speed) ease;
        }

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

        .faq-section .faq-question:hover {
            background-color: #fcfcfc;
        }

        .faq-section .faq-answer {
            padding: 0 1.5em;
            max-height: 0;
            overflow: hidden;
            transition: max-height var(--transition-speed) ease-out, padding var(--transition-speed) ease-out;
        }

        .faq-section .faq-answer p {
            padding-bottom: 1em;
            font-size: 0.95em;
            color: var(--weak-text-color);
        }

        .faq-section .faq-item.active .faq-answer {
            max-height: 200px; /* Adjust as needed */
            padding: 0 1.5em 1em;
        }

        /* CTA Section */
        .cta-section {
            background-color: var(--primary-color);
            color: #fff;
            text-align: center;
            padding: calc(var(--gutter) * 4) 0;
            background-image: linear-gradient(rgba(255, 107, 107, 0.9), rgba(240, 128, 128, 0.9)), url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
        }

        .cta-section h2 {
            font-size: 2.8em;
            margin-bottom: var(--gutter);
            color: #fff;
        }

        .cta-section p {
            font-size: 1.2em;
            margin-bottom: calc(var(--gutter) * 2);
            opacity: 0.9;
        }

        .cta-button-secondary {
            display: inline-block;
            background-color: #fff;
            color: var(--primary-color);
            padding: 1em 2.5em;
            font-size: 1.2em;
            font-weight: bold;
            border-radius: var(--border-radius);
            transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
            box-shadow: 0 5px 20px rgba(0,0,0,0.1);
        }

        .cta-button-secondary:hover,
        .cta-button-secondary:focus {
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            text-decoration: none;
        }

        /* Footer */
        footer {
            background-color: #333;
            color: #bbb;
            padding: calc(var(--gutter) * 3) 0 calc(var(--gutter) * 1.5) 0;
            font-size: 0.9em;
        }

        .footer-content {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            margin-bottom: calc(var(--gutter) * 2);
            padding-bottom: var(--gutter);
            border-bottom: 1px solid #444;
        }

        .footer-section {
            flex: 1;
            min-width: 200px;
            margin-right: var(--gutter);
        }

        .footer-section h3 {
            color: #fff;
            font-size: 1.3em;
            margin-bottom: var(--gutter);
        }

        .footer-section ul {
            list-style: none;
        }

        .footer-section ul li {
            margin-bottom: calc(var(--gutter) / 2);
        }

        .footer-section ul li a {
            color: #bbb;
            transition: color var(--transition-speed) ease;
        }

        .footer-section ul li a:hover,
        .footer-section ul li a:focus {
            color: var(--secondary-color);
            text-decoration: none;
        }

        .footer-bottom {
            text-align: center;
            opacity: 0.7;
        }

        .footer-bottom a {
            color: #bbb;
            margin: 0 0.5em;
            transition: color var(--transition-speed) ease;
        }
        .footer-bottom a:hover,
        .footer-bottom a:focus {
            color: var(--secondary-color);
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            nav ul {
                flex-direction: column;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background-color: var(--card-bg);
                box-shadow: 0 5px 15px rgba(0,0,0,0.1);
                padding: var(--gutter) 0;
                display: none; /* Hidden by default, shown with JS for mobile menu */
            }

            nav ul.show {
                display: flex;
            }

            nav ul li {
                margin: 0;
                text-align: center;
                padding: 0.8em 0;
            }

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

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

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

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

            .footer-content {
                flex-direction: column;
                align-items: center;
                text-align: center;
            }

            .footer-section {
                margin-right: 0;
                margin-bottom: var(--gutter);
            }
        }

        @media (max-width: 768px) {
            .hero {
                padding: calc(var(--gutter) * 3) 0;
            }

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

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

            .section {
                padding: calc(var(--gutter) * 3) 0;
            }

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

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

            .features-section .feature-item {
                flex-direction: column;
                text-align: center;
            }

            .features-section .feature-icon {
                margin-bottom: var(--gutter);
            }
        }

        @media (max-width: 520px) {
            .logo {
                font-size: 1.8em;
            }

            .hero h1 {
                font-size: 1.8em;
            }

            .hero .cta-button {
                padding: 0.8em 1.8em;
                font-size: 1em;
            }

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

            .cta-section p {
                font-size: 1em;
            }

            .cta-button-secondary {
                padding: 0.8em 1.8em;
                font-size: 1em;
            }
        }

/* roulang page: category3 */
:root {
            --primary-color: #e91e63; /* Deep Pink */
            --secondary-color: #2196f3; /* Blue */
            --background-color: #f8f9fa; /* Light Gray */
            --text-color: #333;
            --muted-text-color: #6c757d; /* Muted Gray */
            --border-color: #dee2e6;
            --card-background: #fff;
            --button-hover-bg: #d32f2f; /* Darker Red */
            --button-active-bg: #c62828; /* Even Darker Red */
            --footer-background: #343a40; /* Dark Gray */
            --footer-text-color: #f8f9fa;
            --nav-hover-color: #f8bbd0; /* Lighter Pink */
            --shadow-light: 0 2px 4px rgba(0,0,0,.1);
            --shadow-medium: 0 4px 8px rgba(0,0,0,.15);
            --card-border-radius: 8px;
            --container-max-width: 1200px;
            --spacing-xs: 8px;
            --spacing-sm: 16px;
            --spacing-md: 24px;
            --spacing-lg: 32px;
            --spacing-xl: 48px;
        }

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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background-color: var(--background-color);
        }

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

        a {
            color: var(--secondary-color);
            text-decoration: none;
            transition: color 0.2s ease-in-out;
        }

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

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

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

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

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

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

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

        header nav ul {
            list-style: none;
            display: flex;
        }

        header nav ul li {
            margin-left: var(--spacing-md);
        }

        header nav ul li a {
            color: var(--text-color);
            font-weight: 500;
            padding: var(--spacing-sm) var(--spacing-md);
            transition: color 0.2s ease-in-out, background-color 0.2s ease-in-out;
            border-radius: var(--card-border-radius);
        }

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

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
            color: #fff;
            text-align: center;
            padding: var(--spacing-xl) 0;
            position: relative;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            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-sm);
            text-shadow: 2px 2px 8px rgba(0,0,0,0.7);
        }

        .hero p {
            font-size: 1.2rem;
            max-width: 800px;
            margin: 0 auto var(--spacing-lg);
            text-shadow: 1px 1px 4px rgba(0,0,0,0.7);
        }

        .btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: #fff;
            padding: var(--spacing-sm) var(--spacing-lg);
            border-radius: var(--card-border-radius);
            font-weight: bold;
            transition: background-color 0.2s ease-in-out, transform 0.2s ease-in-out;
            border: none;
            cursor: pointer;
            font-size: 1.1rem;
        }

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

        .btn:active {
            background-color: var(--button-active-bg);
            transform: translateY(0);
        }

        /* Content Sections */
        .section {
            padding: var(--spacing-xl) 0;
        }

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

        .section-subtitle {
            text-align: center;
            font-size: 1.3rem;
            color: var(--muted-text-color);
            max-width: 800px;
            margin: 0 auto var(--spacing-xl);
        }

        /* Card Grid */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: var(--spacing-lg);
        }

        .card {
            background-color: var(--card-background);
            border-radius: var(--card-border-radius);
            box-shadow: var(--shadow-medium);
            overflow: hidden;
            transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
            display: flex;
            flex-direction: column;
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 16px rgba(0,0,0,.2);
        }

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

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

        .card-content h3 {
            font-size: 1.4rem;
            margin-bottom: var(--spacing-sm);
            color: var(--secondary-color);
        }

        .card-content p {
            color: var(--muted-text-color);
            flex-grow: 1;
            margin-bottom: var(--spacing-md);
        }

        .card-content .btn {
            align-self: flex-start; /* Align button to the left */
            margin-top: auto; /* Push button to the bottom */
        }

        /* Feature Section */
        .feature-section {
            background-color: #fff;
        }

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

        .feature-item {
            padding: var(--spacing-md);
        }

        .feature-item i {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: var(--spacing-sm);
        }

        .feature-item h4 {
            font-size: 1.2rem;
            color: var(--text-color);
            margin-bottom: var(--spacing-xs);
        }

        .feature-item p {
            color: var(--muted-text-color);
        }

        /* FAQ Section */
        .faq-section {
            background-color: #fff;
        }
        .faq-list {
            max-width: 800px;
            margin: 0 auto;
        }

        .faq-item {
            margin-bottom: var(--spacing-md);
            border: 1px solid var(--border-color);
            border-radius: var(--card-border-radius);
            background-color: var(--card-background);
            box-shadow: var(--shadow-light);
        }

        .faq-question {
            background-color: var(--card-background);
            color: var(--text-color);
            padding: var(--spacing-md) var(--spacing-lg);
            cursor: pointer;
            font-weight: 500;
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-radius: var(--card-border-radius) var(--card-border-radius) 0 0;
        }

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

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

        .faq-answer {
            padding: var(--spacing-md) var(--spacing-lg);
            color: var(--muted-text-color);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-in-out, padding 0.3s ease-in-out;
            background-color: var(--background-color);
            border-radius: 0 0 var(--card-border-radius) var(--card-border-radius);
        }

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

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

        .cta-section h2 {
            font-size: 2.5rem;
            margin-bottom: var(--spacing-md);
        }

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

        .cta-section .btn {
            background-color: #fff;
            color: var(--primary-color);
            padding: var(--spacing-sm) var(--spacing-xl);
            font-size: 1.2rem;
        }

        .cta-section .btn:hover {
            background-color: var(--nav-hover-color);
            color: #fff;
        }

        /* Footer */
        footer {
            background-color: var(--footer-background);
            color: var(--footer-text-color);
            padding: var(--spacing-xl) 0 var(--spacing-sm);
            font-size: 0.9rem;
        }

        footer .container {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--spacing-lg);
        }

        .footer-section h3 {
            color: #fff;
            margin-bottom: var(--spacing-md);
            font-size: 1.3rem;
        }

        .footer-section p,
        .footer-section ul {
            margin-bottom: var(--spacing-md);
            color: var(--footer-text-color);
            opacity: 0.8;
        }

        .footer-section ul li {
            margin-bottom: var(--spacing-sm);
        }

        .footer-section ul li a {
            color: var(--footer-text-color);
            opacity: 0.9;
        }
        .footer-section ul li a:hover {
            color: #fff;
            opacity: 1;
        }

        .footer-bottom {
            text-align: center;
            padding-top: var(--spacing-md);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            margin-top: var(--spacing-lg);
        }

        .footer-bottom a {
            color: #fff;
            margin: 0 var(--spacing-sm);
        }

        /* Responsive Adjustments */
        @media (max-width: 992px) {
            header nav {
                flex-direction: column;
                align-items: flex-start;
            }
            header nav ul {
                margin-top: var(--spacing-md);
                flex-wrap: wrap;
                justify-content: center;
            }
            header nav ul li {
                margin: var(--spacing-xs) var(--spacing-sm);
            }

            .hero h1 { font-size: 2.5rem; }
            .hero p { font-size: 1.1rem; }

            .feature-grid {
                grid-template-columns: repeat(2, 1fr);
            }

            footer .container {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 768px) {
            h1 { font-size: 2rem; }
            h2 { font-size: 1.75rem; }
            .section-title { font-size: 2rem; }

            .hero { padding: var(--spacing-xl) 0; }
            .hero h1 { font-size: 2.2rem; }

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

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

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

        @media (max-width: 576px) {
            .logo { font-size: 1.5rem; }
            header nav ul li { margin: var(--spacing-xs) var(--spacing-sm); }

            .hero h1 { font-size: 2rem; }
            .hero p { font-size: 1rem; }
            .btn { padding: var(--spacing-sm) var(--spacing-lg); }

            .cta-section h2 { font-size: 2rem; }
            .cta-section p { font-size: 1.1rem; }
            .cta-section .btn { font-size: 1.1rem; }
        }

/* roulang page: category4 */
:root {
            --primary-color: #e91e63;
            --secondary-color: #ff9800;
            --background-color: #1e1e1e;
            --text-color: #ffffff;
            --sub-text-color: #cccccc;
            --border-color: #444444;
            --card-bg: #2c2c2c;
            --input-bg: #333333;
            --button-hover-bg: #f50057;
            --footer-bg: #111111;
            --nav-bg: #1a1a1a;
            --container-width: 1200px;
            --spacing-xs: 8px;
            --spacing-sm: 16px;
            --spacing-md: 24px;
            --spacing-lg: 32px;
            --spacing-xl: 48px;
            --radius-sm: 4px;
            --radius-md: 8px;
            --radius-lg: 12px;
            --shadow-sm: 0 2px 5px rgba(0, 0, 0, 0.2);
            --shadow-md: 0 4px 10px rgba(0, 0, 0, 0.3);
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: 'Microsoft YaHei', 'PingFang SC', 'Hiragino Sans GB', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: var(--background-color);
            color: var(--text-color);
            line-height: 1.6;
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

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

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

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

        .container {
            width: 90%;
            max-width: var(--container-width);
            margin: 0 auto;
        }

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

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

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

        header nav ul {
            list-style: none;
            display: flex;
        }

        header nav ul li {
            margin-left: var(--spacing-md);
        }

        header nav ul li a {
            color: var(--sub-text-color);
            font-weight: 500;
            padding: var(--spacing-sm) var(--spacing-md);
            transition: color 0.3s ease, background-color 0.3s ease;
            border-radius: var(--radius-sm);
        }

        header nav ul li a.active,
        header nav ul li a:hover,
        header nav ul li a:focus {
            color: var(--text-color);
            background-color: rgba(255, 255, 255, 0.1);
            text-decoration: none;
        }

        /* Hero Section */
        .hero {
            background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
            height: 70vh;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
            padding: var(--spacing-xl) var(--spacing-sm);
            position: relative;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.6);
            z-index: 1;
        }

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

        .hero h1 {
            font-size: 3em;
            margin-bottom: var(--spacing-md);
            color: var(--primary-color);
            text-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
        }

        .hero p {
            font-size: 1.4em;
            margin-bottom: var(--spacing-lg);
            color: var(--text-color);
            max-width: 800px;
            text-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
        }

        .cta-button {
            display: inline-block;
            background-color: var(--primary-color);
            color: var(--text-color);
            padding: var(--spacing-sm) var(--spacing-xl);
            font-size: 1.2em;
            font-weight: bold;
            border-radius: var(--radius-md);
            transition: background-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
            box-shadow: var(--shadow-md);
        }

        .cta-button:hover, .cta-button:focus {
            background-color: var(--button-hover-bg);
            transform: translateY(-3px);
            box-shadow: 0 6px 15px rgba(233, 30, 99, 0.5);
            text-decoration: none;
        }

        /* Section Styles */
        .section {
            padding: var(--spacing-xl) 0;
        }

        .section h2 {
            font-size: 2.5em;
            text-align: center;
            margin-bottom: var(--spacing-lg);
            color: var(--primary-color);
        }

        .section p {
            font-size: 1.1em;
            color: var(--sub-text-color);
            max-width: 800px;
            margin: 0 auto var(--spacing-lg);
            text-align: center;
        }

        /* Card Grid */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: var(--spacing-md);
        }

        .card {
            background-color: var(--card-bg);
            border-radius: var(--radius-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: var(--shadow-md);
        }

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

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

        .card-content h3 {
            font-size: 1.4em;
            margin-bottom: var(--spacing-sm);
            color: var(--primary-color);
        }

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

        .card-content .card-link {
            display: inline-block;
            background-color: var(--secondary-color);
            color: var(--text-color);
            padding: var(--spacing-xs) var(--spacing-md);
            border-radius: var(--radius-sm);
            font-weight: bold;
            text-align: center;
            transition: background-color 0.3s ease;
            margin-top: auto;
        }

        .card-content .card-link:hover, .card-content .card-link:focus {
            background-color: #e68a00;
            text-decoration: none;
        }

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

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

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

        .faq-question {
            font-size: 1.2em;
            font-weight: bold;
            color: var(--primary-color);
            cursor: pointer;
            position: relative;
            padding-right: var(--spacing-lg);
        }

        .faq-question::after {
            content: '+';
            position: absolute;
            right: 0;
            font-size: 1.3em;
            transition: transform 0.3s ease;
        }

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

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

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

        /* Footer */
        footer {
            background-color: var(--footer-bg);
            color: var(--sub-text-color);
            padding: var(--spacing-xl) 0 var(--spacing-sm);
            margin-top: auto;
            font-size: 0.9em;
        }

        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            margin-bottom: var(--spacing-md);
        }

        .footer-section {
            flex: 1;
            min-width: 200px;
            margin: var(--spacing-md);
        }

        .footer-section h3 {
            color: var(--text-color);
            margin-bottom: var(--spacing-sm);
            font-size: 1.3em;
        }

        .footer-section ul {
            list-style: none;
        }

        .footer-section ul li {
            margin-bottom: var(--spacing-xs);
        }

        .footer-section ul li a {
            color: var(--sub-text-color);
        }

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

        .footer-bottom {
            text-align: center;
            padding-top: var(--spacing-md);
            border-top: 1px solid var(--border-color);
            font-size: 0.85em;
        }

        .footer-bottom a {
            color: var(--sub-text-color);
        }

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

        /* Responsive */
        @media (max-width: 768px) {
            header nav {
                flex-direction: column;
            }
            header nav ul {
                flex-direction: column;
                align-items: center;
                margin-top: var(--spacing-sm);
            }
            header nav ul li {
                margin: var(--spacing-xs) 0;
            }

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

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

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

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

            .footer-content {
                flex-direction: column;
                align-items: center;
                text-align: center;
            }
            .footer-section {
                margin: var(--spacing-sm);
            }
        }

        @media (max-width: 520px) {
             .logo {
                font-size: 1.5em;
            }
            .hero h1 {
                font-size: 1.8em;
            }
            .hero p {
                font-size: 1em;
            }
            .cta-button {
                padding: var(--spacing-sm) var(--spacing-lg);
                font-size: 1em;
            }
            .section h2 {
                font-size: 1.8em;
            }
            .faq-question {
                font-size: 1.1em;
            }
            .footer-bottom {
                font-size: 0.8em;
            }
        }