/* roulang page: index */
:root {
            --primary-color: #007bff;
            --secondary-color: #6c757d;
            --accent-color: #ffc107;
            --background-color: #f8f9fa;
            --card-background: #ffffff;
            --text-color: #343a40;
            --muted-text-color: #6c757d;
            --border-color: #dee2e6;
            --border-radius: 8px;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
            --container-max-width: 1200px;
            --spacing-xs: 8px;
            --spacing-sm: 16px;
            --spacing-md: 24px;
            --spacing-lg: 32px;
            --spacing-xl: 48px;
        }

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
            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 0.2s ease-in-out;
        }

        a:hover {
            color: #0056b3;
            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(--card-background);
            padding: var(--spacing-sm) 0;
            box-shadow: var(--shadow);
            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);
            text-decoration: none;
        }

        .nav-links a {
            margin-left: var(--spacing-lg);
            color: var(--text-color);
            font-weight: 500;
            padding: var(--spacing-sm) var(--spacing-md);
            border-radius: var(--border-radius);
            transition: background-color 0.2s ease-in-out, color 0.2s ease-in-out;
        }

        .nav-links a:hover,
        .nav-links a.active {
            background-color: var(--primary-color);
            color: #fff;
            text-decoration: none;
        }

        /* Mobile Navigation */
        .mobile-nav-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.8em;
            cursor: pointer;
            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(--card-background);
                padding: var(--spacing-md);
                box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
                border-top: 1px solid var(--border-color);
            }
            .nav-links.open {
                display: flex;
            }
            .nav-links a {
                margin: var(--spacing-sm) 0;
                padding: var(--spacing-md);
                width: 100%;
                text-align: center;
            }
            .mobile-nav-toggle {
                display: block;
            }
        }

        /* 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-xl) 0;
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 60vh;
        }

        .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: 3.5em;
            margin-bottom: var(--spacing-md);
            line-height: 1.2;
        }

        .hero p {
            font-size: 1.4em;
            margin-bottom: var(--spacing-lg);
            color: rgba(255, 255, 255, 0.9);
        }

        .btn {
            display: inline-block;
            padding: var(--spacing-sm) var(--spacing-lg);
            background-color: var(--accent-color);
            color: var(--text-color);
            font-size: 1.1em;
            font-weight: bold;
            border: none;
            border-radius: var(--border-radius);
            cursor: pointer;
            transition: background-color 0.2s ease-in-out, transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
            text-decoration: none;
        }

        .btn:hover {
            background-color: #e0a800;
            transform: translateY(-2px);
            box-shadow: var(--shadow);
            text-decoration: none;
        }

        .btn-primary {
            background-color: var(--primary-color);
            color: #fff;
        }

        .btn-primary:hover {
            background-color: #0056b3;
        }

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

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

        .section-subtitle {
            text-align: center;
            font-size: 1.3em;
            color: var(--muted-text-color);
            margin-bottom: var(--spacing-xl);
        }

        /* Content Blocks / Cards */
        .content-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: var(--spacing-lg);
        }

        .card {
            background-color: var(--card-background);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            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 20px rgba(0, 0, 0, 0.12);
        }

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

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

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

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

        .card-meta {
            font-size: 0.85em;
            color: var(--muted-text-color);
            display: flex;
            justify-content: space-between;
            margin-top: auto;
        }

        .card-link {
            display: block;
            text-align: right;
            margin-top: var(--spacing-sm);
        }

        /* Category Links */
        .category-section {
            background-color: var(--card-background);
            padding: var(--spacing-xl) 0;
        }

        .category-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: var(--spacing-md);
        }

        .category-card {
            background-color: var(--background-color);
            border: 1px solid var(--border-color);
            border-radius: var(--border-radius);
            padding: var(--spacing-md);
            text-align: center;
            transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out, background-color 0.2s ease-in-out;
        }

        .category-card:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow);
            background-color: var(--card-background);
        }

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

        .category-card p {
            font-size: 0.95em;
            color: var(--muted-text-color);
        }

        /* FAQ Section */
        .faq-section {
            background-color: rgba(255, 255, 255, 0.5); /* Slightly different background */
        }

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

        .faq-question {
            font-size: 1.2em;
            font-weight: bold;
            color: var(--primary-color);
            cursor: pointer;
            padding: var(--spacing-md);
            position: relative;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: background-color 0.2s ease-in-out;
        }

        .faq-question::after {
            content: '+';
            font-size: 1.5em;
            transition: transform 0.2s ease-in-out;
        }

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

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

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

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

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

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

        /* Footer */
        footer {
            background-color: #343a40;
            color: rgba(255, 255, 255, 0.7);
            padding: var(--spacing-xl) 0;
            margin-top: auto;
        }

        .footer-content {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: var(--spacing-lg);
        }

        .footer-brand {
            font-size: 1.8em;
            font-weight: bold;
            color: #fff;
            margin-bottom: var(--spacing-sm);
        }

        .footer-links a {
            color: rgba(255, 255, 255, 0.7);
            display: block;
            margin-bottom: var(--spacing-sm);
        }

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

        .copyright {
            text-align: center;
            padding: var(--spacing-md) 0;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            font-size: 0.9em;
        }

        /* Responsive Adjustments */
        @media (max-width: 992px) {
            .hero h1 {
                font-size: 3em;
            }
            .hero p {
                font-size: 1.2em;
            }
            h2 {
                font-size: 2.2em;
            }
        }

        @media (max-width: 768px) {
            .hero {
                min-height: 40vh;
            }
            .hero h1 {
                font-size: 2.5em;
            }
            .hero p {
                font-size: 1.1em;
            }
            h2 {
                font-size: 2em;
            }
            .section-subtitle {
                font-size: 1.1em;
            }
            .content-grid {
                grid-template-columns: 1fr;
            }
            .category-grid {
                grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
            }
            .footer-content {
                flex-direction: column;
                text-align: center;
            }
            .footer-brand {
                font-size: 1.6em;
            }
            .footer-links {
                margin-bottom: var(--spacing-md);
            }
        }

        @media (max-width: 576px) {
            .hero h1 {
                font-size: 2em;
            }
            .hero p {
                font-size: 1em;
            }
            h2 {
                font-size: 1.8em;
            }
            .cta-section h2 {
                font-size: 2.2em;
            }
            .cta-section p {
                font-size: 1em;
            }
        }

/* roulang page: article */
:root {
            --primary-color: #ff6f61;
            --secondary-color: #ff9a8b;
            --accent-color: #4a90e2;
            --background-color: #f4f4f4;
            --text-color: #333;
            --light-text-color: #777;
            --border-color: #ddd;
            --card-background: #fff;
            --header-footer-bg: #333;
            --header-footer-text: #fff;
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --border-radius: 8px;
            --box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: '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: 90%;
            max-width: var(--container-max-width);
            margin: 0 auto;
            padding: var(--spacing-unit) 0;
        }
        a {
            color: var(--accent-color);
            text-decoration: none;
            transition: color 0.3s ease;
        }
        a:hover {
            color: var(--primary-color);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button {
            cursor: pointer;
            border: none;
            background: none;
            font-size: 1rem;
        }

        /* Header & Nav */
        header {
            background-color: var(--header-footer-bg);
            color: var(--header-footer-text);
            padding: var(--spacing-unit) 0;
            box-shadow: 0 2px 5px rgba(0,0,0,0.2);
        }
        header nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        header .logo {
            font-size: 1.8rem;
            font-weight: bold;
            color: var(--secondary-color);
        }
        .nav-links a {
            color: var(--header-footer-text);
            margin-left: calc(var(--spacing-unit) * 1.5);
            font-size: 1.1rem;
            transition: color 0.3s ease;
        }
        .nav-links a:hover, .nav-links a.active {
            color: var(--secondary-color);
            font-weight: bold;
        }
        .mobile-nav-toggle {
            display: none;
            font-size: 2rem;
            color: var(--header-footer-text);
        }

        /* Main Content Area */
        main {
            flex-grow: 1;
            padding: calc(var(--spacing-unit) * 3) 0;
        }
        .article-content {
            background-color: var(--card-background);
            padding: calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }
        .article-title {
            font-size: 2.5rem;
            font-weight: bold;
            color: var(--primary-color);
            margin-bottom: var(--spacing-unit);
            text-align: center;
        }
        .article-meta {
            text-align: center;
            color: var(--light-text-color);
            font-size: 0.9rem;
            margin-bottom: calc(var(--spacing-unit) * 2);
        }
        .article-meta span {
            margin: 0 var(--spacing-unit);
        }
        .article-body {
            font-size: 1.1rem;
            color: var(--text-color);
            margin-top: calc(var(--spacing-unit) * 2);
            line-height: 1.8;
        }
        .article-body p {
            margin-bottom: calc(var(--spacing-unit) * 1.5);
        }
        .article-body h2, .article-body h3 {
            color: var(--primary-color);
            margin-top: calc(var(--spacing-unit) * 2);
            margin-bottom: var(--spacing-unit);
            line-height: 1.3;
        }
        .article-body h2 { font-size: 2rem; }
        .article-body h3 { font-size: 1.6rem; }
        .article-body img {
            border-radius: var(--border-radius);
            margin: var(--spacing-unit) auto;
        }
        .article-body a {
            font-weight: bold;
        }
        .no-content {
            text-align: center;
            padding: calc(var(--spacing-unit) * 5) 0;
            font-size: 1.5rem;
            color: var(--light-text-color);
        }
        .no-content a {
            display: inline-block;
            margin-top: var(--spacing-unit);
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 2.5);
            background-color: var(--primary-color);
            color: white;
            border-radius: var(--border-radius);
            transition: background-color 0.3s ease;
        }
        .no-content a:hover {
            background-color: var(--secondary-color);
        }

        /* Section Specifics (Example for a more complete article structure) */
        .hero-section {
            background-image: url('/assets/images/backpic/back-1.webp'); /* Example background */
            background-size: cover;
            background-position: center;
            color: var(--header-footer-text);
            text-align: center;
            padding: calc(var(--spacing-unit) * 8) var(--spacing-unit);
            position: relative;
        }
        .hero-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.6);
            z-index: 1;
        }
        .hero-content {
            position: relative;
            z-index: 2;
        }
        .hero-title {
            font-size: 3rem;
            font-weight: bold;
            margin-bottom: var(--spacing-unit);
        }
        .hero-subtitle {
            font-size: 1.5rem;
            color: var(--secondary-color);
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        .section {
            padding: calc(var(--spacing-unit) * 3) 0;
        }
        .section h2 {
            font-size: 2rem;
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 2);
            color: var(--primary-color);
        }
        .card-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, 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 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 8px 16px rgba(0,0,0,0.2);
        }
        .card img {
            width: 100%;
            height: 200px; /* Fixed height for card images */
            object-fit: cover;
        }
        .card-content {
            padding: calc(var(--spacing-unit) * 1.5);
            flex-grow: 1;
        }
        .card-title {
            font-size: 1.3rem;
            font-weight: bold;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
        }
        .card-text {
            font-size: 1rem;
            color: var(--light-text-color);
            margin-bottom: calc(var(--spacing-unit) * 1.5);
        }
        .card-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: white;
            padding: calc(var(--spacing-unit) * 0.8) calc(var(--spacing-unit) * 1.5);
            border-radius: var(--border-radius);
            margin-top: auto; /* Pushes button to the bottom */
            transition: background-color 0.3s ease;
        }
        .card-button:hover {
            background-color: var(--primary-color);
        }

        .faq-section {
            background-color: var(--card-background);
            padding: calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }
        .faq-item {
            margin-bottom: var(--spacing-unit);
            border-bottom: 1px solid var(--border-color);
            padding-bottom: var(--spacing-unit);
        }
        .faq-item:last-child {
            border-bottom: none;
            padding-bottom: 0;
        }
        .faq-question {
            font-size: 1.2rem;
            font-weight: bold;
            color: var(--primary-color);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            transition: transform 0.3s ease;
        }
        .faq-item.open .faq-question::after {
            transform: rotate(45deg);
        }
        .faq-answer {
            font-size: 1.1rem;
            color: var(--text-color);
            margin-top: var(--spacing-unit);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out;
        }
        .faq-item.open .faq-answer {
            max-height: 200px; /* Adjust as needed */
        }

        .cta-section {
            text-align: center;
            background-color: var(--primary-color);
            color: white;
            padding: calc(var(--spacing-unit) * 5) var(--spacing-unit);
        }
        .cta-section h2 {
            font-size: 2.5rem;
            margin-bottom: var(--spacing-unit);
            color: white;
        }
        .cta-section p {
            font-size: 1.2rem;
            margin-bottom: calc(var(--spacing-unit) * 2);
        }
        .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: white;
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            font-size: 1.2rem;
            font-weight: bold;
            transition: background-color 0.3s ease;
        }
        .cta-button:hover {
            background-color: var(--secondary-color);
        }

        /* Footer */
        footer {
            background-color: var(--header-footer-bg);
            color: var(--header-footer-text);
            padding: calc(var(--spacing-unit) * 3) 0;
            margin-top: auto; /* Pushes footer to the bottom */
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: calc(var(--spacing-unit) * 3);
        }
        .footer-brand {
            font-size: 2rem;
            font-weight: bold;
            color: var(--secondary-color);
            margin-bottom: var(--spacing-unit);
        }
        .footer-links h4 {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-unit);
            color: var(--secondary-color);
        }
        .footer-links a, .footer-links p {
            display: block;
            margin-bottom: calc(var(--spacing-unit) * 0.8);
            color: var(--header-footer-text);
            font-size: 0.95rem;
        }
        .footer-links a:hover {
            color: var(--secondary-color);
        }
        .copyright {
            text-align: center;
            padding-top: calc(var(--spacing-unit) * 2);
            border-top: 1px solid rgba(255, 255, 255, 0.2);
            margin-top: calc(var(--spacing-unit) * 3);
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            header nav {
                flex-wrap: wrap;
            }
            .nav-links {
                display: none; /* Hidden by default on mobile */
                width: 100%;
                flex-direction: column;
                text-align: center;
                background-color: var(--header-footer-bg);
                padding: var(--spacing-unit) 0;
                position: absolute;
                top: 70px; /* Adjust based on header height */
                left: 0;
                z-index: 10;
            }
            .nav-links.active {
                display: flex;
            }
            .nav-links a {
                margin: var(--spacing-unit) 0;
                font-size: 1.2rem;
            }
            .mobile-nav-toggle {
                display: block;
                order: 1; /* Move toggle to the right */
            }
            header .logo {
                order: 0; /* Logo to the left */
            }

            .article-title {
                font-size: 2rem;
            }
            .article-body {
                font-size: 1rem;
            }
            .hero-title {
                font-size: 2.5rem;
            }
            .hero-subtitle {
                font-size: 1.2rem;
            }
            .section h2 {
                font-size: 1.8rem;
            }
            .card-container {
                grid-template-columns: 1fr;
            }
            .cta-section h2 {
                font-size: 2rem;
            }
            .cta-section p {
                font-size: 1.1rem;
            }
            .footer-content {
                grid-template-columns: 1fr;
            }
        }

/* roulang page: category1 */
:root {
            --primary-color: #e91e63; /* 品牌主色，例如深粉色 */
            --secondary-color: #f50057; /* 品牌强调色 */
            --background-color: #f8f9fa; /* 浅灰色背景 */
            --text-color: #333; /* 主文字颜色 */
            --light-text-color: #6c757d; /* 弱文字颜色 */
            --border-color: #dee2e6; /* 边框颜色 */
            --card-bg: #ffffff; /* 卡片背景 */
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --rounded-md: 8px;
            --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
            --transition-fast: all 0.3s ease-in-out;
        }

        body {
            font-family: 'Arial', sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background-color: var(--background-color);
            margin: 0;
            padding: 0;
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        .container {
            width: 90%;
            max-width: var(--container-max-width);
            margin: 0 auto;
            padding: calc(var(--spacing-unit) * 2) 0;
        }

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

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

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

        button {
            cursor: pointer;
            border: none;
            background: none;
            padding: 0;
        }

        /* Header & Navigation */
        header {
            background-color: #ffffff;
            box-shadow: var(--shadow-md);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        nav.container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: var(--spacing-unit) 0;
        }

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

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

        .nav-links {
            display: flex;
            gap: calc(var(--spacing-unit) * 2);
        }

        .nav-links a {
            color: var(--text-color);
            font-weight: 500;
            padding: 0.5rem 1rem;
            border-radius: var(--rounded-md);
            transition: var(--transition-fast);
        }

        .nav-links a.active {
            background-color: var(--primary-color);
            color: #ffffff;
        }

        .nav-links a:hover {
            background-color: rgba(233, 30, 99, 0.1);
            color: var(--primary-color);
            text-decoration: none;
        }

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

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-2.webp');
            background-size: cover;
            background-position: center;
            color: #ffffff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 8) 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: 3.5rem;
            margin-bottom: var(--spacing-unit);
            line-height: 1.2;
        }

        .hero p {
            font-size: 1.3rem;
            color: rgba(255, 255, 255, 0.9);
        }

        /* Section Title */
        .section-title {
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 4);
            padding-top: calc(var(--spacing-unit) * 2);
        }

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

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

        /* Content Cards */
        .cards-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: calc(var(--spacing-unit) * 2.5);
        }

        .card {
            background-color: var(--card-bg);
            border-radius: var(--rounded-md);
            box-shadow: var(--shadow-md);
            overflow: hidden;
            transition: var(--transition-fast);
            display: flex;
            flex-direction: column;
        }

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

        .card img {
            width: 100%;
            height: 220px; /* Fixed height for consistency */
            object-fit: cover;
        }

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

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

        .card-content p {
            font-size: 0.95rem;
            color: var(--light-text-color);
            margin-bottom: calc(var(--spacing-unit) * 1.5);
            flex-grow: 1; /* Allow description to take available space */
        }

        .card-content .btn {
            display: inline-block;
            background-color: var(--secondary-color);
            color: #ffffff;
            padding: 0.8rem 1.8rem;
            border-radius: var(--rounded-md);
            font-weight: bold;
            text-align: center;
            transition: var(--transition-fast);
            margin-top: auto; /* Push to bottom */
        }

        .card-content .btn:hover {
            background-color: var(--primary-color);
            text-decoration: none;
        }

        /* Feature Section */
        .feature-section {
            background-color: #ffffff;
            border-radius: var(--rounded-md);
            box-shadow: var(--shadow-md);
            margin-top: calc(var(--spacing-unit) * 5);
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: calc(var(--spacing-unit) * 4);
            align-items: center;
        }

        .feature-content {
            padding: calc(var(--spacing-unit) * 5);
        }

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

        .feature-content p {
            font-size: 1.1rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-unit);
        }

        .feature-image {
            text-align: center;
            padding: calc(var(--spacing-unit) * 3);
        }

        .feature-image img {
            border-radius: var(--rounded-md);
            max-width: 100%;
            height: auto;
            box-shadow: var(--shadow-md);
        }

        /* CTA Section */
        .cta-section {
            background-color: var(--primary-color);
            color: #ffffff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 6) 0;
            margin-top: calc(var(--spacing-unit) * 5);
            border-radius: var(--rounded-md);
        }

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

        .cta-section p {
            font-size: 1.2rem;
            margin-bottom: calc(var(--spacing-unit) * 3);
            opacity: 0.9;
        }

        .cta-section .btn {
            display: inline-block;
            background-color: #ffffff;
            color: var(--primary-color);
            padding: 1rem 2.5rem;
            border-radius: var(--rounded-md);
            font-weight: bold;
            font-size: 1.1rem;
            box-shadow: var(--shadow-md);
            transition: var(--transition-fast);
        }

        .cta-section .btn:hover {
            background-color: var(--secondary-color);
            color: #ffffff;
            text-decoration: none;
            box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
        }

        /* FAQ Section */
        .faq-section {
            margin-top: calc(var(--spacing-unit) * 5);
            padding: calc(var(--spacing-unit) * 4) 0;
            background-color: #ffffff;
            border-radius: var(--rounded-md);
            box-shadow: var(--shadow-md);
        }

        .faq-item {
            margin-bottom: var(--spacing-unit);
            border-bottom: 1px solid var(--border-color);
            padding-bottom: var(--spacing-unit);
        }
        .faq-item:last-child {
            border-bottom: none;
            padding-bottom: 0;
        }

        .faq-question {
            font-size: 1.2rem;
            font-weight: 500;
            color: var(--text-color);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: var(--spacing-unit) 0;
        }

        .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            color: var(--primary-color);
            transition: var(--transition-fast);
        }

        .faq-item.active .faq-question::after {
            content: '-';
        }

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

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


        /* Footer */
        footer {
            background-color: #333;
            color: rgba(255, 255, 255, 0.8);
            margin-top: auto; /* Push to bottom */
            padding-top: calc(var(--spacing-unit) * 4);
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: calc(var(--spacing-unit) * 3);
            padding-bottom: calc(var(--spacing-unit) * 3);
            border-bottom: 1px solid rgba(255, 255, 255, 0.2);
        }

        .footer-brand {
            font-size: 2rem;
            font-weight: bold;
            color: #ffffff;
            grid-column: span 2;
        }

        .footer-links h4 {
            font-size: 1.2rem;
            color: #ffffff;
            margin-bottom: var(--spacing-unit);
        }

        .footer-links a, .footer-links p {
            display: block;
            margin-bottom: 0.7rem;
            color: rgba(255, 255, 255, 0.7);
            font-size: 0.95rem;
            transition: var(--transition-fast);
        }

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

        .copyright {
            text-align: center;
            padding: calc(var(--spacing-unit) * 2) 0;
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.6);
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            nav.container {
                flex-wrap: wrap;
            }

            .nav-links {
                display: none;
                flex-direction: column;
                width: 100%;
                text-align: center;
                padding-top: var(--spacing-unit);
            }

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

            .nav-links a {
                padding: 1rem 0;
                margin: 0.5rem 0;
                border-bottom: 1px solid var(--border-color);
            }
            .nav-links a:last-child {
                border-bottom: none;
            }

            .mobile-nav-toggle {
                display: block;
                order: 1; /* Place toggle button next to logo */
            }

            .logo {
                order: 0; /* Ensure logo is first */
                flex-grow: 1;
            }

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

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

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

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

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

            .feature-content, .feature-image {
                padding: calc(var(--spacing-unit) * 3);
            }

            .feature-image img {
                max-width: 80%;
            }

            .footer-content {
                grid-template-columns: 1fr 1fr;
            }
            .footer-brand {
                grid-column: span 2;
            }
            .footer-links:nth-of-type(2),
            .footer-links:nth-of-type(3) {
                grid-column: span 1;
            }
        }

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

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

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

            .section-title h2 {
                font-size: 1.8rem;
            }

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

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

            .cta-section .btn {
                padding: 0.8rem 1.8rem;
                font-size: 1rem;
            }

            .footer-content {
                grid-template-columns: 1fr;
            }
            .footer-brand, .footer-links {
                grid-column: span 1 !important;
                text-align: center;
            }
            .footer-links h4 {
                margin-top: var(--spacing-unit);
            }
        }

/* roulang page: category2 */
:root {
            --primary-color: #d9534f;
            --secondary-color: #f0ad4e;
            --background-color: #f8f9fa;
            --text-color: #333;
            --text-muted-color: #666;
            --border-color: #dee2e6;
            --card-background: #fff;
            --footer-background: #343a40;
            --footer-text-color: #fff;
            --container-max-width: 1140px;
            --spacing-unit: 1rem;
            --border-radius: 0.25rem;
            --box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
        }

        * {
            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);
            scroll-behavior: smooth;
        }

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

        a:hover {
            color: #c94542;
            text-decoration: underline;
        }

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

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

        header {
            background-color: var(--card-background);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
            padding: var(--spacing-unit) 0;
        }

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

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

        .nav-links {
            display: flex;
            gap: var(--spacing-unit) * 2;
        }

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

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

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

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

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

        .hero {
            background-image: url('/assets/images/backpic/back-3.webp');
            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);
        }

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

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

        .hero p {
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto;
        }

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

        .section h2 {
            text-align: center;
            font-size: 2.5rem;
            margin-bottom: calc(var(--spacing-unit) * 3);
            color: var(--text-color);
        }

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

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

        .content-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1);
        }

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

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

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

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

        .card-content a.btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: #fff;
            padding: 0.75rem 1.5rem;
            border-radius: var(--border-radius);
            text-decoration: none;
            font-weight: bold;
            transition: background-color 0.2s ease-in-out;
            align-self: flex-start;
            margin-top: auto;
        }

        .card-content a.btn:hover {
            background-color: #c94542;
            text-decoration: none;
        }

        .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) * 2;
            color: #fff;
        }

        .cta-section p {
            font-size: 1.1rem;
            margin-bottom: var(--spacing-unit) * 3;
        }

        .cta-section a.btn {
            display: inline-block;
            background-color: var(--secondary-color);
            color: var(--text-color);
            padding: 1rem 2rem;
            border-radius: var(--border-radius);
            text-decoration: none;
            font-weight: bold;
            font-size: 1.1rem;
            transition: background-color 0.2s ease-in-out;
        }

        .cta-section a.btn:hover {
            background-color: #e0a040;
        }

        .faq-section {
            background-color: var(--card-background);
        }

        .faq-section h2 {
            color: var(--text-color);
        }

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

        .faq-question {
            background-color: #fdfdfd;
            padding: var(--spacing-unit) * 1.5;
            cursor: pointer;
            font-weight: bold;
            display: flex;
            justify-content: space-between;
            align-items: center;
            position: relative;
        }

        .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            transition: transform 0.2s ease-in-out;
        }

        .faq-item.open .faq-question::after {
            content: '-';
            transform: rotate(0deg);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-in-out;
            padding: 0 var(--spacing-unit) * 1.5;
            background-color: var(--card-background);
        }

        .faq-answer p {
            padding: var(--spacing-unit) * 1.5 0;
        }

        footer {
            background-color: var(--footer-background);
            color: var(--footer-text-color);
            padding: calc(var(--spacing-unit) * 4) 0;
        }

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

        .footer-brand {
            font-size: 2rem;
            font-weight: bold;
            margin-bottom: var(--spacing-unit);
        }

        .footer-links h4 {
            margin-bottom: var(--spacing-unit) * 1.5;
            font-size: 1.2rem;
            border-bottom: 2px solid var(--secondary-color);
            padding-bottom: var(--spacing-unit) * 0.5;
            display: inline-block;
        }

        .footer-links a,
        .footer-links p {
            color: rgba(255, 255, 255, 0.8);
            margin-bottom: var(--spacing-unit);
            display: block;
            text-decoration: none;
        }

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

        .copyright {
            text-align: center;
            padding-top: calc(var(--spacing-unit) * 2);
            margin-top: calc(var(--spacing-unit) * 3);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
        }

        @media (max-width: 992px) {
            .nav-links {
                gap: var(--spacing-unit) * 1.5;
            }
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero p {
                font-size: 1.1rem;
            }
            .section h2 {
                font-size: 2.2rem;
            }
            .cta-section h2 {
                font-size: 2.4rem;
            }
        }

        @media (max-width: 768px) {
            .mobile-nav-toggle {
                display: block;
            }
            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 70px; /* Adjust based on header height */
                left: 0;
                width: 100%;
                background-color: var(--card-background);
                box-shadow: 0 4px 8px rgba(0,0,0,0.1);
                padding: var(--spacing-unit) 0;
                z-index: 1000;
            }
            .nav-links.active {
                display: flex;
            }
            .nav-links a {
                padding: var(--spacing-unit) * 1.5 var(--spacing-unit) * 2;
                width: 100%;
                text-align: center;
            }
            .nav-links a.active::after {
                display: none;
            }
            .hero {
                padding: calc(var(--spacing-unit) * 6) 0;
            }
            .hero h1 {
                font-size: 2.2rem;
            }
            .section {
                padding: calc(var(--spacing-unit) * 3) 0;
            }
            .section h2 {
                font-size: 2rem;
                margin-bottom: var(--spacing-unit) * 2;
            }
            .content-grid {
                grid-template-columns: 1fr;
            }
            .cta-section {
                padding: calc(var(--spacing-unit) * 4) 0;
            }
            .cta-section h2 {
                font-size: 2.2rem;
            }
            .footer-content {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .footer-links h4 {
                margin-bottom: var(--spacing-unit);
            }
            .footer-links a,
            .footer-links p {
                margin-bottom: var(--spacing-unit) * 0.8;
            }
            .copyright {
                padding-top: var(--spacing-unit);
                margin-top: var(--spacing-unit) * 2;
            }
        }

/* roulang page: category3 */
/* --- CSS Variables (Design Tokens) --- */
        :root {
            --color-primary: #e91e63; /* Pink */
            --color-secondary: #f50057; /* Deep Pink */
            --color-accent: #ffc107; /* Amber */
            --color-background: #f8f9fa;
            --color-surface: #ffffff;
            --color-text-primary: #212529;
            --color-text-secondary: #495057;
            --color-text-disabled: #6c757d;
            --color-border: #dee2e6;
            --color-link: var(--color-secondary);
            --color-hover-overlay: rgba(0, 0, 0, 0.05);
            --color-focus-outline: rgba(233, 30, 99, 0.5);

            --font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            --font-size-base: 1rem;
            --line-height-base: 1.6;

            --spacing-unit: 1rem;
            --container-max-width: 1200px;

            --radius-sm: 0.25rem;
            --radius-md: 0.5rem;
            --radius-lg: 1rem;

            --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
            --shadow-md: 0 4px 8px rgba(0,0,0,0.1);
            --shadow-lg: 0 12px 24px rgba(0,0,0,0.15);

            --header-height: 70px;
            --footer-height: auto;
        }

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

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

        h1, h2, h3, h4, h5, h6 {
            margin-bottom: var(--spacing-unit);
            line-height: 1.3;
            font-weight: 600;
            color: var(--color-text-primary);
        }

        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);
            color: var(--color-text-secondary);
        }

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

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

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

        button, input, select, textarea {
            font-family: inherit;
            font-size: inherit;
            color: inherit;
        }

        button {
            cursor: pointer;
            border: none;
            background: none;
            outline: none;
        }

        input, textarea {
            width: 100%;
            padding: calc(var(--spacing-unit) * 0.75);
            border: 1px solid var(--color-border);
            border-radius: var(--radius-sm);
            background-color: var(--color-surface);
        }

        textarea {
            min-height: 150px;
            resize: vertical;
        }

        /* --- Utilities --- */
        .container {
            width: 90%;
            max-width: var(--container-max-width);
            margin-left: auto;
            margin-right: auto;
            padding-left: var(--spacing-unit);
            padding-right: var(--spacing-unit);
        }

        .btn {
            display: inline-block;
            padding: calc(var(--spacing-unit) * 0.75) calc(var(--spacing-unit) * 1.5);
            border-radius: var(--radius-md);
            font-weight: 500;
            text-decoration: none;
            transition: all 0.2s ease-in-out;
            cursor: pointer;
            border: none;
        }

        .btn-primary {
            background-color: var(--color-primary);
            color: #fff;
        }

        .btn-primary:hover,
        .btn-primary:focus {
            background-color: var(--color-secondary);
            color: #fff;
            text-decoration: none;
            box-shadow: var(--shadow-md);
        }

        .btn-secondary {
            background-color: transparent;
            color: var(--color-primary);
            border: 2px solid var(--color-primary);
        }

        .btn-secondary:hover,
        .btn-secondary:focus {
            background-color: var(--color-primary);
            color: #fff;
            text-decoration: none;
            box-shadow: var(--shadow-md);
        }

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

        .section-title {
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 2);
            font-size: 2rem;
            color: var(--color-text-primary);
        }

        .section-subtitle {
            text-align: center;
            color: var(--color-text-secondary);
            margin-bottom: calc(var(--spacing-unit) * 3);
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

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

        .card-image {
            width: 100%;
            height: 250px; /* Fixed height for consistency */
            background-size: cover;
            background-position: center;
        }

        .card-content {
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .card-title {
            font-size: 1.3rem;
            color: var(--color-text-primary);
            margin-bottom: calc(var(--spacing-unit) * 0.5);
        }

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

        .card-footer {
            padding: calc(var(--spacing-unit) * 0.75) calc(var(--spacing-unit) * 1.5);
            background-color: var(--color-background);
            border-top: 1px solid var(--color-border);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .badge {
            display: inline-block;
            padding: 0.25em 0.75em;
            font-size: 0.8rem;
            font-weight: 500;
            border-radius: var(--radius-sm);
            margin-right: var(--spacing-unit);
        }

        .badge-primary {
            background-color: var(--color-primary);
            color: #fff;
        }

        .badge-secondary {
            background-color: var(--color-secondary);
            color: #fff;
        }

        /* --- Header & Navigation --- */
        header {
            background-color: var(--color-surface);
            box-shadow: var(--shadow-sm);
            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;
        }

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

        .nav-links {
            display: flex;
            gap: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
        }

        .nav-links a {
            color: var(--color-text-secondary);
            font-weight: 500;
            padding: calc(var(--spacing-unit) * 0.5) 0;
            position: relative;
            transition: color 0.2s ease-in-out;
        }

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

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

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

        /* --- Hero Section --- */
        .hero {
            background-image: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
            color: #fff;
            padding: calc(var(--spacing-unit) * 6) 0;
            text-align: center;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 60vh;
            position: relative;
            overflow: hidden;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: inherit; /* Inherit background image */
            z-index: -1;
            filter: blur(10px); /* Apply blur */
            transform: scale(1.1); /* Slightly scale up to cover edges */
        }

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

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

        .hero p {
            font-size: 1.2rem;
            color: rgba(255, 255, 255, 0.9);
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        /* --- Category Specific Content --- */
        .category-intro {
            text-align: center;
            padding: calc(var(--spacing-unit) * 4) 0;
            background-color: var(--color-surface);
        }

        .category-title {
            font-size: 2.8rem;
            color: var(--color-primary);
            margin-bottom: var(--spacing-unit);
        }

        .category-subtitle {
            font-size: 1.3rem;
            color: var(--color-text-secondary);
            max-width: 700px;
            margin: 0 auto;
        }

        .category-features {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: calc(var(--spacing-unit) * 2);
            margin-top: calc(var(--spacing-unit) * 3);
        }

        .feature-item {
            text-align: center;
            padding: var(--spacing-unit);
        }

        .feature-icon {
            font-size: 2.5rem;
            color: var(--color-primary);
            margin-bottom: var(--spacing-unit);
        }

        .feature-item h4 {
            font-size: 1.3rem;
            color: var(--color-text-primary);
            margin-bottom: calc(var(--spacing-unit) * 0.5);
        }

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

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

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

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

        .content-card-image {
            width: 100%;
            height: 200px;
            background-size: cover;
            background-position: center;
        }

        .content-card-body {
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .content-card-title {
            font-size: 1.2rem;
            color: var(--color-text-primary);
            margin-bottom: calc(var(--spacing-unit) * 0.5);
        }

        .content-card-meta {
            font-size: 0.85rem;
            color: var(--color-text-disabled);
            margin-bottom: var(--spacing-unit);
        }

        .content-card-description {
            font-size: 0.9rem;
            color: var(--color-text-secondary);
            margin-bottom: var(--spacing-unit);
        }

        .content-card-footer {
            padding: calc(var(--spacing-unit) * 0.75) calc(var(--spacing-unit) * 1.5);
            background-color: var(--color-background);
            border-top: 1px solid var(--color-border);
            display: flex;
            justify-content: flex-end;
            align-items: center;
        }

        /* --- FAQ Section --- */
        .faq-section {
            background-color: var(--color-background);
            padding: calc(var(--spacing-unit) * 4) 0;
        }

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

        .faq-question {
            background-color: var(--color-surface);
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 500;
            transition: background-color 0.2s ease-in-out;
        }

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

        .faq-question::after {
            content: '+';
            font-size: 1.5rem;
            transition: transform 0.2s ease-in-out;
        }

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

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-in-out, padding 0.3s ease-in-out;
            background-color: var(--color-surface);
            padding: 0 var(--spacing-unit) calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 1.5); /* Top padding is 0 */
            padding-left: calc(var(--spacing-unit) * 1.5); /* Left padding for content */
        }

        .faq-item.active .faq-answer {
            max-height: 500px; /* Sufficient height to show content */
            padding-top: var(--spacing-unit); /* Add top padding when active */
        }

        .faq-answer p {
            margin-bottom: 0;
        }

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

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

        .cta-section p {
            font-size: 1.2rem;
            color: rgba(255, 255, 255, 0.9);
            margin-bottom: calc(var(--spacing-unit) * 2);
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

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

        .cta-section .btn-primary:hover,
        .cta-section .btn-primary:focus {
            background-color: var(--color-accent);
            color: var(--color-text-primary);
        }

        /* --- Footer --- */
        footer {
            background-color: var(--color-text-primary);
            color: rgba(255, 255, 255, 0.7);
            padding: calc(var(--spacing-unit) * 4) 0;
            font-size: 0.9rem;
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: calc(var(--spacing-unit) * 2);
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .footer-brand {
            font-size: 2rem;
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: var(--spacing-unit);
        }

        .footer-links h4 {
            color: #fff;
            margin-bottom: calc(var(--spacing-unit) * 1.5);
            font-size: 1.1rem;
        }

        .footer-links a {
            display: block;
            color: rgba(255, 255, 255, 0.7);
            margin-bottom: var(--spacing-unit);
            transition: color 0.2s ease-in-out;
        }

        .footer-links a:hover {
            color: #fff;
            text-decoration: none;
        }

        .footer-links p {
            color: rgba(255, 255, 255, 0.7);
            line-height: 1.7;
        }

        .copyright {
            text-align: center;
            padding-top: var(--spacing-unit);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            font-size: 0.85rem;
        }

        /* --- Responsive Design --- */
        @media (max-width: 992px) {
            h1 { font-size: 2.25rem; }
            h2 { font-size: 1.75rem; }
            .hero h1 { font-size: 2.5rem; }
            .hero p { font-size: 1.1rem; }
            .category-title { font-size: 2.2rem; }
            .section-title { font-size: 1.8rem; }
            .section-subtitle { font-size: 1.1rem; }
            .cta-section h2 { font-size: 2rem; }

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

        @media (max-width: 768px) {
            .nav-links {
                display: none; /* Hide navigation links by default on mobile */
                flex-direction: column;
                position: absolute;
                top: var(--header-height);
                left: 0;
                right: 0;
                background-color: var(--color-surface);
                padding: var(--spacing-unit);
                box-shadow: var(--shadow-md);
            }

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

            .nav-links a {
                width: 100%;
                padding: var(--spacing-unit);
                text-align: center;
                border-bottom: 1px solid var(--color-border);
            }

            .nav-links a:last-child {
                border-bottom: none;
            }

            .nav-links a.active::after {
                display: none; /* No underline on mobile nav */
            }

            .mobile-nav-toggle {
                display: block; /* Show hamburger icon */
            }

            .hero {
                min-height: 40vh;
                padding: calc(var(--spacing-unit) * 4) 0;
            }

            .hero h1 { font-size: 2rem; }
            .hero p { font-size: 1rem; }

            .category-features, .content-grid {
                grid-template-columns: 1fr;
            }

            .footer-content {
                grid-template-columns: 1fr;
                text-align: center;
            }

            .footer-brand {
                font-size: 1.8rem;
            }

            .footer-links {
                margin-bottom: var(--spacing-unit);
            }
        }

        @media (max-width: 576px) {
            h1 { font-size: 2rem; }
            h2 { font-size: 1.5rem; }
            .hero h1 { font-size: 2rem; }
            .hero p { font-size: 1rem; }
            .category-title { font-size: 2rem; }
            .section-title { font-size: 1.6rem; }
            .section-subtitle { font-size: 1rem; }
            .cta-section h2 { font-size: 1.8rem; }
            .cta-section p { font-size: 1rem; }

            .container {
                width: 95%;
            }

            .card-image, .content-card-image {
                height: 180px;
            }
        }

/* roulang page: category4 */
:root {
            --primary-color: #007bff;
            --secondary-color: #6c757d;
            --background-color: #f8f9fa;
            --text-color: #333;
            --weak-text-color: #666;
            --border-color: #ddd;
            --card-background: #fff;
            --footer-background: #343a40;
            --footer-text-color: #f8f9fa;
            --hover-color: #0056b3;
            --focus-outline-color: rgba(0, 123, 255, 0.5);
            --border-radius: 8px;
            --shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
            --container-width: 1140px;
            --spacing-sm: 10px;
            --spacing-md: 20px;
            --spacing-lg: 30px;
        }

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

        body {
            font-family: 'Arial', sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background-color: var(--background-color);
        }

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

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

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

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

        h1, h2, h3, h4 {
            margin-bottom: var(--spacing-md);
            line-height: 1.4;
        }

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

        .btn {
            display: inline-block;
            padding: var(--spacing-sm) var(--spacing-md);
            border: none;
            border-radius: var(--border-radius);
            background-color: var(--primary-color);
            color: white;
            font-size: 1rem;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease;
        }

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

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

        /* Header */
        header {
            background-color: var(--card-background);
            padding: var(--spacing-md) 0;
            box-shadow: var(--shadow);
            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(--text-color);
            text-decoration: none;
        }

        .nav-links {
            display: flex;
            gap: var(--spacing-md);
        }

        .nav-links a {
            color: var(--text-color);
            font-size: 1.1rem;
            padding: var(--spacing-sm) 0;
            position: relative;
        }

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

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

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

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

        /* Hero Section */
        .hero {
            background-image: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
            color: white;
            padding: var(--spacing-lg) 0;
            text-align: center;
            min-height: 60vh;
            display: flex;
            justify-content: center;
            align-items: center;
        }

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

        .hero h1 {
            font-size: 3.5rem;
            margin-bottom: var(--spacing-sm);
        }

        .hero p {
            font-size: 1.3rem;
            margin-bottom: var(--spacing-lg);
            opacity: 0.9;
        }

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

        .section-title {
            text-align: center;
            margin-bottom: var(--spacing-lg);
            font-size: 2.25rem;
            color: var(--text-color);
        }

        .section-subtitle {
            text-align: center;
            color: var(--weak-text-color);
            font-size: 1.25rem;
            margin-bottom: var(--spacing-lg);
        }

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

        .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 16px rgba(0, 0, 0, 0.15);
        }

        .card-image {
            width: 100%;
            height: 200px; /* Fixed height for consistency */
            object-fit: cover; /* Ensures image covers the area */
        }

        .card-content {
            padding: var(--spacing-md);
            flex-grow: 1; /* Allows content to take up available space */
            display: flex;
            flex-direction: column;
            justify-content: space-between; /* Pushes button to bottom if needed */
        }

        .card-title {
            font-size: 1.5rem;
            margin-bottom: var(--spacing-sm);
            color: var(--text-color);
        }

        .card-description {
            font-size: 0.95rem;
            color: var(--weak-text-color);
            margin-bottom: var(--spacing-md);
        }

        .card-btn {
            margin-top: auto; /* Pushes button to the bottom */
            display: block;
            width: 100%;
            text-align: center;
        }

        /* FAQ Section */
        .faq-section {
            background-color: #fff;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            padding: var(--spacing-lg);
        }

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

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

        .faq-question {
            font-size: 1.25rem;
            font-weight: bold;
            cursor: pointer;
            position: relative;
            padding-left: 30px; /* Space for icon */
        }

        .faq-question::before {
            content: '+';
            position: absolute;
            left: 0;
            font-size: 1.5rem;
            color: var(--primary-color);
            transition: transform 0.3s ease;
        }

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

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

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

        /* CTA Section */
        .cta-section {
            background-color: var(--primary-color);
            color: white;
            text-align: center;
            padding: var(--spacing-lg) 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);
            opacity: 0.9;
        }

        .cta-section .btn {
            background-color: white;
            color: var(--primary-color);
            font-weight: bold;
            padding: var(--spacing-sm) var(--spacing-lg);
        }

        .cta-section .btn:hover {
            background-color: var(--hover-color);
            color: white;
        }

        /* Footer */
        footer {
            background-color: var(--footer-background);
            color: var(--footer-text-color);
            padding: var(--spacing-lg) 0;
        }

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

        .footer-brand {
            font-size: 2rem;
            font-weight: bold;
            margin-bottom: var(--spacing-md);
        }

        .footer-links h4 {
            color: white;
            margin-bottom: var(--spacing-md);
        }

        .footer-links a, .footer-links p {
            color: rgba(255, 255, 255, 0.7);
            display: block;
            margin-bottom: var(--spacing-sm);
            font-size: 0.95rem;
        }

        .footer-links a:hover {
            color: white;
        }

        .copyright {
            text-align: center;
            padding-top: var(--spacing-lg);
            margin-top: var(--spacing-lg);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.6);
        }

        /* Responsive */
        @media (max-width: 768px) {
            h1 { font-size: 2rem; }
            h2 { font-size: 1.75rem; }
            .hero h1 { font-size: 2.8rem; }
            .hero p { font-size: 1.1rem; }
            .section-title { font-size: 2rem; }

            .nav-links {
                display: none; /* Hidden by default on mobile */
                flex-direction: column;
                position: absolute;
                top: 70px; /* Adjust based on header height */
                right: var(--spacing-md);
                background-color: var(--card-background);
                width: 200px;
                box-shadow: var(--shadow);
                padding: var(--spacing-md);
                border-radius: var(--border-radius);
            }
            .nav-links.active {
                display: flex;
            }
            .nav-links a {
                width: 100%;
                text-align: left;
                margin-bottom: var(--spacing-sm);
            }
            .mobile-nav-toggle {
                display: block;
            }

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

            .footer-content {
                grid-template-columns: 1fr;
                text-align: center;
            }
        }

        @media (max-width: 576px) {
            .hero {
                min-height: 40vh;
            }
            .hero h1 {
                font-size: 2rem;
            }
            .hero p {
                font-size: 1rem;
            }
            .section {
                padding: var(--spacing-lg) 0;
            }
            .cta-section h2 {
                font-size: 2rem;
            }
            .cta-section p {
                font-size: 1rem;
            }
        }