/* roulang page: index */
:root {
            --primary-color: #ff6f61;
            --secondary-color: #4a4a4a;
            --accent-color: #f9a825;
            --background-color: #f8f8f8;
            --text-color: #333;
            --light-text-color: #777;
            --border-color: #eee;
            --card-background: #fff;
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --border-radius: 8px;
            --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
        }

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

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

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

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

        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(--card-background);
            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);
        }

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

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

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

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

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

        nav ul li a:hover::after,
        nav ul li a.active::after {
            width: 100%;
        }

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

        .mobile-menu {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            background-color: var(--card-background);
            box-shadow: var(--box-shadow);
            padding: var(--spacing-unit);
            z-index: 999;
        }

        .mobile-menu ul {
            flex-direction: column;
            align-items: center;
        }

        .mobile-menu ul li {
            margin: var(--spacing-unit) 0;
        }

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            color: #fff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 6) var(--spacing-unit);
            position: relative;
            overflow: hidden;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.7));
        }

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

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

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

        .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: #fff;
            padding: var(--spacing-unit) calc(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;
            box-shadow: var(--box-shadow);
        }

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

        /* Section */
        .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(--secondary-color);
        }

        /* Content Cards */
        .card-grid {
            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(-5px);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
        }

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

        .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: 1.4rem;
            margin-bottom: var(--spacing-unit);
            color: var(--secondary-color);
            line-height: 1.3;
        }

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

        .card-meta {
            font-size: 0.85rem;
            color: var(--light-text-color);
            margin-top: auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

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

        /* Latest Updates Section */
        .latest-updates {
            background-color: #fff;
        }

        .latest-updates .card-grid {
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
        }

        .latest-updates .card-title {
            font-size: 1.2rem;
        }

        .latest-updates .card-description {
            font-size: 0.9rem;
        }

        .latest-updates .card-meta {
            font-size: 0.8rem;
        }

        /* Feature Section */
        .features {
            background-color: var(--background-color);
        }

        .features .feature-item {
            display: flex;
            align-items: center;
            margin-bottom: calc(var(--spacing-unit) * 3);
            gap: var(--spacing-unit) * 2;
            flex-wrap: wrap;
        }

        .features .feature-item.reverse {
            flex-direction: row-reverse;
        }

        .features .feature-image-wrapper {
            flex: 1 1 400px;
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: var(--box-shadow);
        }

        .features .feature-content {
            flex: 1 1 400px;
        }

        .features h3 {
            font-size: 2rem;
            margin-bottom: var(--spacing-unit) * 1.5;
            color: var(--secondary-color);
        }

        .features ul {
            list-style: disc;
            margin-left: calc(var(--spacing-unit) * 2);
        }

        .features ul li {
            margin-bottom: var(--spacing-unit);
            color: var(--light-text-color);
        }

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

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

        .faq-question {
            background-color: #fefefe;
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
            font-weight: bold;
            cursor: pointer;
            position: relative;
            color: var(--secondary-color);
        }

        .faq-question::after {
            content: '+';
            position: absolute;
            right: var(--spacing-unit) * 1.5;
            font-size: 1.2rem;
            transition: transform 0.3s ease;
        }

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

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            padding: 0 var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
            transition: max-height 0.3s ease, padding 0.3s ease;
        }

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

        .faq-answer p {
            color: var(--light-text-color);
        }

        /* Call to Action */
        .cta-section {
            background-color: var(--primary-color);
            color: #fff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 5) 0;
            position: relative;
        }

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

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

        .cta-section .cta-button {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 2.5);
            font-size: 1.2rem;
        }

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


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

        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: var(--spacing-unit) * 2;
        }

        .footer-logo {
            font-size: 1.8rem;
            font-weight: bold;
            color: var(--primary-color);
            margin-bottom: var(--spacing-unit);
        }

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

        .footer-links ul li {
            margin-bottom: 0.8rem;
        }

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

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

        .footer-contact p,
        .footer-contact span {
            margin-bottom: 0.5rem;
        }

        .footer-copyright {
            text-align: center;
            padding-top: calc(var(--spacing-unit) * 3);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            margin-top: calc(var(--spacing-unit) * 3);
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            .hero h1 {
                font-size: 2.8rem;
            }

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

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

            .features .feature-item {
                flex-direction: column;
            }

            .features .feature-item.reverse {
                flex-direction: column;
            }

            .features .feature-image-wrapper,
            .features .feature-content {
                flex-basis: 100%;
            }
        }

        @media (max-width: 768px) {
            nav ul {
                display: none;
            }

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

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

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

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

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

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

        @media (max-width: 576px) {
            .hero h1 {
                font-size: 2.2rem;
            }

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

            .cta-section h2 {
                font-size: 2.4rem;
            }
        }

/* roulang page: article */
:root {
            --primary-color: #007bff;
            --secondary-color: #6c757d;
            --background-color: #f8f9fa;
            --text-color: #212529;
            --light-text-color: #495057;
            --border-color: #dee2e6;
            --card-background: #ffffff;
            --border-radius: 8px;
            --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            --spacing-unit: 16px;
            --container-max-width: 1200px;
        }

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background-color: var(--background-color);
            scroll-behavior: smooth;
        }

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

        a:hover {
            color: #0056b3;
        }

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

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

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

        /* Header & Navigation */
        header {
            background-color: var(--card-background);
            box-shadow: 0 2px 8px rgba(0,0,0,.05);
            padding: var(--spacing-unit) 0;
            position: sticky;
            top: 0;
            z-index: 1000;
        }

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

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

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

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

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

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

        header nav ul li a:hover::after {
            width: 100%;
        }

        .mobile-nav-toggle {
            display: none;
            font-size: 1.8em;
            color: var(--text-color);
        }

        .mobile-menu {
            display: none;
            background-color: var(--card-background);
            padding: var(--spacing-unit);
            box-shadow: 0 4px 8px rgba(0,0,0,.05);
        }

        .mobile-menu ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: var(--spacing-unit);
        }

        .mobile-menu ul li a {
            display: block;
            padding: 0.8rem var(--spacing-unit);
            color: var(--light-text-color);
            font-weight: 500;
        }

        .mobile-menu ul li a.active {
            color: var(--primary-color);
            font-weight: bold;
        }

        /* 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: #ffffff;
            text-align: center;
            padding: calc(var(--spacing-unit) * 6) 0;
            margin-bottom: calc(var(--spacing-unit) * 4);
        }

        .hero h1 {
            font-size: 3em;
            margin-bottom: calc(var(--spacing-unit) * 1.5);
            line-height: 1.3;
        }

        .hero p {
            font-size: 1.2em;
            max-width: 800px;
            margin: 0 auto;
            opacity: 0.9;
        }

        /* Main Content Area */
        main .container {
            padding-top: calc(var(--spacing-unit) * 2);
            padding-bottom: calc(var(--spacing-unit) * 4);
        }

        .article-header {
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .article-header h1 {
            font-size: 2.8em;
            margin-bottom: calc(var(--spacing-unit) * 1);
            line-height: 1.2;
        }

        .article-meta {
            font-size: 0.9em;
            color: var(--secondary-color);
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        .article-meta span {
            margin: 0 var(--spacing-unit);
        }

        .article-content {
            margin-top: calc(var(--spacing-unit) * 2);
            background-color: var(--card-background);
            padding: calc(var(--spacing-unit) * 3);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }

        .article-content h2, .article-content h3 {
            margin-top: calc(var(--spacing-unit) * 2);
            margin-bottom: var(--spacing-unit);
            line-height: 1.4;
        }

        .article-content p {
            margin-bottom: var(--spacing-unit);
            font-size: 1.1em;
        }

        .article-content img {
            margin: calc(var(--spacing-unit) * 2) auto;
            border-radius: calc(var(--border-radius) / 2);
            box-shadow: 0 2px 8px rgba(0,0,0,.1);
        }

        .no-content {
            text-align: center;
            padding: calc(var(--spacing-unit) * 5) 0;
        }

        .no-content h2 {
            font-size: 2em;
            color: var(--secondary-color);
            margin-bottom: var(--spacing-unit);
        }

        .no-content p {
            font-size: 1.1em;
            margin-bottom: calc(var(--spacing-unit) * 2);
        }

        .cta-button {
            display: inline-block;
            background-color: var(--primary-color);
            color: #ffffff;
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 2.5);
            border-radius: var(--border-radius);
            font-size: 1.1em;
            font-weight: bold;
            transition: background-color 0.3s ease, transform 0.2s ease;
        }

        .cta-button:hover {
            background-color: #0056b3;
            transform: translateY(-2px);
        }

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

        .section-title {
            text-align: center;
            font-size: 2.2em;
            margin-bottom: calc(var(--spacing-unit) * 3);
            position: relative;
            padding-bottom: calc(var(--spacing-unit) * 1.5);
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 3px;
            background-color: var(--primary-color);
            border-radius: 2px;
        }

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

        .faq-question {
            background-color: #f0f2f5;
            padding: calc(var(--spacing-unit) * 1.5) var(--spacing-unit);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 500;
            transition: background-color 0.3s ease;
        }

        .faq-question:hover {
            background-color: #e9ecef;
        }

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

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

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

        .faq-answer p {
            padding: var(--spacing-unit) 0;
            color: var(--light-text-color);
        }

        /* Footer */
        footer {
            background-color: #343a40;
            color: #ffffff;
            padding: calc(var(--spacing-unit) * 4) 0 calc(var(--spacing-unit) * 2) 0;
            font-size: 0.9em;
        }

        .footer-content {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: calc(var(--spacing-unit) * 3);
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .footer-brand, .footer-links, .footer-contact {
            flex: 1;
            min-width: 200px;
        }

        .footer-logo {
            font-size: 1.8em;
            font-weight: bold;
            color: #ffffff;
            margin-bottom: var(--spacing-unit);
        }

        .footer-content p {
            opacity: 0.7;
        }

        .footer-links h4 {
            margin-bottom: var(--spacing-unit);
            color: #adb5bd;
            font-size: 1.2em;
        }

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

        .footer-links ul li {
            margin-bottom: calc(var(--spacing-unit) / 2);
        }

        .footer-links ul li a {
            color: #ffffff;
            opacity: 0.8;
            transition: opacity 0.3s ease;
        }

        .footer-links ul li a:hover {
            opacity: 1;
        }

        .footer-copyright {
            text-align: center;
            padding-top: calc(var(--spacing-unit) * 2);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            opacity: 0.7;
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            header nav ul {
                gap: calc(var(--spacing-unit) * 1.5);
            }
            .hero h1 {
                font-size: 2.5em;
            }
            .article-header h1 {
                font-size: 2.2em;
            }
        }

        @media (max-width: 768px) {
            .mobile-nav-toggle {
                display: block;
            }
            header nav ul {
                display: none;
            }
            .hero {
                padding: calc(var(--spacing-unit) * 4) 0;
            }
            .hero h1 {
                font-size: 2em;
            }
            .hero p {
                font-size: 1em;
            }
            .article-header h1 {
                font-size: 1.8em;
            }
            .article-content {
                padding: calc(var(--spacing-unit) * 2);
            }
            .section-title {
                font-size: 1.8em;
            }
            .footer-content {
                flex-direction: column;
                text-align: center;
            }
            .footer-brand, .footer-links, .footer-contact {
                width: 100%;
            }
        }

        @media (max-width: 576px) {
            :root {
                --spacing-unit: 14px;
                --border-radius: 6px;
            }
            .hero {
                padding: calc(var(--spacing-unit) * 3) 0;
            }
            .hero h1 {
                font-size: 1.8em;
            }
            .article-header h1 {
                font-size: 1.6em;
            }
            .article-meta {
                font-size: 0.8em;
            }
            .cta-button {
                padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
                font-size: 1em;
            }
        }

/* roulang page: category1 */
:root {
            --primary-color: #007bff;
            --secondary-color: #6c757d;
            --background-color: #f8f9fa;
            --text-color: #333;
            --weak-text-color: #777;
            --border-color: #dee2e6;
            --card-background: #fff;
            --button-hover-bg: #0056b3;
            --footer-background: #343a40;
            --footer-text-color: #e9ecef;
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --border-radius: 0.25rem;
            --box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            --hero-background-gradient: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
        }

        body {
            margin: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: var(--background-color);
            color: var(--text-color);
            line-height: 1.6;
            overflow-x: hidden;
        }

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

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

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

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

        h1, h2, h3, h4, h5, h6 {
            margin-top: calc(var(--spacing-unit) * 1.5);
            margin-bottom: var(--spacing-unit);
            line-height: 1.3;
        }

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

        header {
            background-color: #ffffff;
            box-shadow: var(--box-shadow);
            padding: var(--spacing-unit) 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);
        }

        header nav ul {
            list-style: none;
            margin: 0;
            padding: 0;
            display: flex;
        }

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

        header nav ul li a {
            color: var(--text-color);
            font-weight: 500;
            padding: 0.5rem 1rem;
            transition: color 0.3s ease, background-color 0.3s ease;
            border-radius: var(--border-radius);
        }

        header nav ul li a.active {
            color: #fff;
            background-color: var(--primary-color);
        }
        
        header nav ul li a:not(.active):hover {
            background-color: var(--primary-color-light);
            color: #fff;
        }

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

        .mobile-menu {
            display: none;
            background-color: #ffffff;
            padding: var(--spacing-unit);
            position: absolute;
            top: 100%;
            left: 0;
            right: 0;
            z-index: 999;
        }
        .mobile-menu ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        .mobile-menu ul li {
            margin-bottom: var(--spacing-unit);
        }
        .mobile-menu ul li a {
             display: block;
             padding: var(--spacing-unit);
             color: var(--text-color);
        }
        .mobile-menu ul li a.active {
            background-color: var(--primary-color);
            color: #fff;
        }


        .hero {
            background-image: url('/assets/images/backpic/back-2.webp');
            background-size: cover;
            background-position: center;
            color: #fff;
            padding: calc(var(--spacing-unit) * 8) 0 calc(var(--spacing-unit) * 4);
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            overflow: hidden;
        }

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

        .hero .hero-content {
            position: relative;
            z-index: 2;
            max-width: 800px;
        }

        .hero h1 {
            font-size: 3.5rem;
            margin-bottom: var(--spacing-unit);
            color: #fff;
        }

        .hero p {
            font-size: 1.3rem;
            margin-bottom: calc(var(--spacing-unit) * 2);
            color: rgba(255, 255, 255, 0.9);
        }

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

        .cta-button:hover, .cta-button:focus {
            background-color: var(--button-hover-bg);
            transform: translateY(-2px);
            text-decoration: none;
        }
        
        main {
            padding: calc(var(--spacing-unit) * 4) 0;
        }

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

        .section h2 {
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 3);
            font-size: 2.2rem;
            color: var(--text-color);
        }

        .category-grid {
            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(-5px);
            box-shadow: 0 8px 15px rgba(0,0,0,0.15);
        }

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

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

        .card .card-content h3 {
            margin-top: 0;
            font-size: 1.5rem;
            margin-bottom: var(--spacing-unit);
        }
        
        .card .card-content p {
            color: var(--weak-text-color);
            font-size: 0.95rem;
            flex-grow: 1;
            margin-bottom: var(--spacing-unit);
        }

        .card .card-content .card-tags {
            margin-top: auto;
            padding-top: var(--spacing-unit);
        }

        .card .card-content .card-tags span {
            background-color: #e9ecef;
            color: var(--text-color);
            padding: 0.3rem 0.7rem;
            border-radius: calc(var(--border-radius) / 2);
            font-size: 0.85rem;
            margin-right: 0.5rem;
            margin-bottom: 0.5rem;
            display: inline-block;
        }

        .feature-section {
            background-color: #fff;
            padding: calc(var(--spacing-unit) * 4) 0;
            text-align: center;
        }

        .feature-section h2 {
            font-size: 2.2rem;
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

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

        .feature-item {
            text-align: center;
        }

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

        .feature-item h3 {
            font-size: 1.4rem;
            margin-bottom: var(--spacing-unit) * 0.5;
        }

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

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

        .faq-section h2 {
            text-align: center;
            margin-bottom: calc(var(--spacing-unit) * 3);
            font-size: 2.2rem;
        }

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

        .faq-item .question {
            font-weight: bold;
            cursor: pointer;
            position: relative;
            padding-left: 30px;
            transition: color 0.3s ease;
        }
        .faq-item .question:hover {
            color: var(--primary-color);
        }

        .faq-item .question::before, .faq-item .question::after {
            content: '';
            position: absolute;
            top: 50%;
            transform: translateY(-50%);
            width: 15px;
            height: 2px;
            background-color: var(--text-color);
            transition: transform 0.3s ease;
        }
        .faq-item .question::before {
            left: 0;
            transform: translateY(-50%) rotate(90deg);
        }
        .faq-item .question::after {
            left: 0;
            transform: translateY(-50%);
        }

        .faq-item .question.active::before {
             transform: translateY(-50%) rotate(180deg);
        }
        .faq-item .question.active::after {
            transform: translateY(-50%) rotate(180deg);
        }

        .faq-item .answer {
            display: none;
            margin-top: var(--spacing-unit);
            color: var(--weak-text-color);
            font-size: 0.95rem;
            padding-left: 10px;
        }

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

        .cta-section h2 {
            font-size: 2.5rem;
            margin-bottom: var(--spacing-unit) * 2;
            color: #fff;
        }

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

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

        .cta-section .cta-button:hover, .cta-section .cta-button:focus {
            background-color: #e9ecef;
            transform: translateY(-2px);
        }

        footer {
            background-color: var(--footer-background);
            color: var(--footer-text-color);
            padding: calc(var(--spacing-unit) * 4) 0 calc(var(--spacing-unit) * 2);
            font-size: 0.9rem;
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: var(--spacing-unit) * 3;
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .footer-brand, .footer-links, .footer-contact {
            display: flex;
            flex-direction: column;
        }

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

        .footer-links h4 {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-unit);
            color: #fff;
            border-bottom: 1px solid var(--weak-text-color);
            padding-bottom: 0.5rem;
        }

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

        .footer-links ul li {
            margin-bottom: 0.7rem;
        }

        .footer-links ul li a {
            color: var(--footer-text-color);
            transition: color 0.3s ease;
        }

        .footer-links ul li a:hover {
            color: #fff;
        }
        
        .footer-contact p {
            margin-bottom: 0.7rem;
        }

        .footer-copyright {
            text-align: center;
            border-top: 1px solid var(--footer-background);
            padding-top: var(--spacing-unit);
            color: var(--weak-text-color);
        }

        @media (max-width: 992px) {
            .container {
                padding: 0 calc(var(--spacing-unit) * 1.5);
            }

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

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

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

            .footer-content {
                grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            }
        }

        @media (max-width: 768px) {
            header nav ul {
                display: none;
            }
            .mobile-nav-toggle {
                display: block;
            }

            .hero {
                padding: calc(var(--spacing-unit) * 6) 0 calc(var(--spacing-unit) * 3);
            }

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

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

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

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

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

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

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

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

            .footer-content {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .footer-brand, .footer-links, .footer-contact {
                align-items: center;
            }
        }

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

            .hero {
                padding: calc(var(--spacing-unit) * 4) 0 calc(var(--spacing-unit) * 2);
            }
             .hero h1 {
                font-size: 1.8rem;
            }
            .hero p {
                font-size: 0.9rem;
            }
            .cta-button {
                padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
                font-size: 1rem;
            }
            .section h2, .feature-section h2, .faq-section h2, .cta-section h2 {
                font-size: 1.8rem;
            }
             .card .card-content {
                padding: var(--spacing-unit) var(--spacing-unit);
            }
             .card .card-content h3 {
                font-size: 1.3rem;
            }
             .card img {
                height: 180px;
            }
        }

/* roulang page: category2 */
:root {
            --primary-color: #e91e63;
            --secondary-color: #f50057;
            --background-color: #121212;
            --text-color: #ffffff;
            --sub-text-color: #b3b3b3;
            --border-color: #424242;
            --card-background: #1e1e1e;
            --accent-color: #ff4081;
            --button-hover-bg: #d81b60;
            --container-width: 1200px;
            --spacing-unit: 16px;
            --border-radius: 8px;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
            --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-family);
            background-color: var(--background-color);
            color: var(--text-color);
            line-height: 1.6;
            overflow-x: hidden;
        }

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

        header {
            background-color: rgba(0, 0, 0, 0.7);
            padding: var(--spacing-unit) 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            backdrop-filter: blur(10px);
        }

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

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

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

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

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

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

        nav ul li 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;
            color: var(--text-color);
            font-size: 2em;
            cursor: pointer;
        }

        .mobile-menu {
            display: none;
            background-color: var(--card-background);
            padding: var(--spacing-unit);
            position: absolute;
            top: 100%;
            left: 0;
            right: 0;
            z-index: 999;
        }

        .mobile-menu ul {
            flex-direction: column;
        }

        .mobile-menu ul li {
            margin: var(--spacing-unit) 0;
        }

        .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;
            height: 60vh;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            position: relative;
            overflow: hidden;
        }

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

        .hero-content {
            position: relative;
            z-index: 1;
            padding: calc(var(--spacing-unit) * 3);
        }

        .hero h1 {
            font-size: 3em;
            margin-bottom: var(--spacing-unit);
            color: var(--primary-color);
            text-shadow: var(--shadow);
        }

        .hero p {
            font-size: 1.4em;
            margin-bottom: var(--spacing-unit) * 2;
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
            color: var(--sub-text-color);
        }

        .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: var(--text-color);
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 2);
            border-radius: var(--border-radius);
            text-decoration: none;
            font-weight: bold;
            font-size: 1.1em;
            transition: background-color 0.3s ease, transform 0.2s ease;
            box-shadow: var(--shadow);
        }

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

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

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

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

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

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 20px rgba(233, 30, 99, 0.4);
        }

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

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

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

        .card-content p {
            font-size: 0.95em;
            color: var(--sub-text-color);
            flex-grow: 1;
            margin-bottom: var(--spacing-unit) * 1.5;
        }

        .card-button {
            display: block;
            text-align: center;
            background-color: var(--secondary-color);
            color: var(--text-color);
            padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
            border-radius: var(--border-radius);
            text-decoration: none;
            font-weight: bold;
            transition: background-color 0.3s ease;
            margin-top: auto;
        }

        .card-button:hover {
            background-color: var(--button-hover-bg);
        }

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

        .faq-section h2 {
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

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

        .faq-question {
            font-size: 1.2em;
            font-weight: bold;
            cursor: pointer;
            position: relative;
            padding-left: calc(var(--spacing-unit) * 2);
        }

        .faq-question::before {
            content: '+';
            position: absolute;
            left: 0;
            font-size: 1.4em;
            color: var(--accent-color);
        }

        .faq-item.open .faq-question::before {
            content: '-';
        }

        .faq-answer {
            font-size: 1em;
            color: var(--sub-text-color);
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out;
            padding-left: calc(var(--spacing-unit) * 2);
            margin-top: var(--spacing-unit);
        }

        .faq-item.open .faq-answer {
            max-height: 200px; /* Adjust as needed */
        }

        .cta-section {
            text-align: center;
            padding: calc(var(--spacing-unit) * 6) 0;
            background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('/assets/images/backpic/back-2.webp');
            background-size: cover;
            background-position: center;
            position: relative;
            overflow: hidden;
        }
         .cta-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.5);
        }

        .cta-section h2 {
            font-size: 2.8em;
            margin-bottom: var(--spacing-unit) * 2;
            color: var(--primary-color);
            text-shadow: var(--shadow);
        }

        .cta-section p {
            font-size: 1.2em;
            margin-bottom: var(--spacing-unit) * 3;
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
            color: var(--sub-text-color);
        }

        footer {
            background-color: #1e1e1e;
            padding: calc(var(--spacing-unit) * 4) 0;
            color: var(--sub-text-color);
            font-size: 0.9em;
        }

        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: calc(var(--spacing-unit) * 3);
            margin-bottom: var(--spacing-unit) * 3;
        }

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

        .footer-links h4, .footer-contact h4 {
            color: var(--text-color);
            margin-bottom: var(--spacing-unit) * 1.5;
            font-size: 1.1em;
        }

        .footer-links ul, .footer-contact ul {
            list-style: none;
        }

        .footer-links ul li, .footer-contact p {
            margin-bottom: var(--spacing-unit);
        }

        .footer-links ul li a, .footer-contact a {
            color: var(--sub-text-color);
            text-decoration: none;
            transition: color 0.3s ease;
        }

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

        .footer-copyright {
            text-align: center;
            border-top: 1px solid var(--border-color);
            padding-top: var(--spacing-unit) * 2;
        }

        /* Responsive adjustments */
        @media (max-width: 992px) {
            .container {
                padding: 0 var(--spacing-unit);
            }
            .hero h1 {
                font-size: 2.5em;
            }
            .hero p {
                font-size: 1.2em;
            }
            .section h2 {
                font-size: 2.2em;
            }
            .card-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-content {
                grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            }
        }

        @media (max-width: 768px) {
            nav ul {
                display: none;
            }
            .mobile-nav-toggle {
                display: block;
            }
            .hero h1 {
                font-size: 2em;
            }
            .hero p {
                font-size: 1.1em;
            }
            .section {
                padding: calc(var(--spacing-unit) * 4) 0;
            }
            .section h2 {
                font-size: 2em;
            }
            .card-grid {
                grid-template-columns: 1fr;
            }
            .footer-content {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .footer-brand, .footer-links, .footer-contact {
                margin-bottom: var(--spacing-unit) * 2;
            }
            .footer-brand .footer-logo {
                font-size: 1.8em;
            }
        }

        @media (max-width: 520px) {
            .hero {
                height: 50vh;
            }
            .hero h1 {
                font-size: 1.8em;
            }
            .hero p {
                font-size: 1em;
            }
            .cta-button {
                padding: var(--spacing-unit) var(--spacing-unit);
                font-size: 1em;
            }
            .section h2 {
                font-size: 1.8em;
            }
            .faq-question {
                font-size: 1.1em;
            }
            .faq-answer {
                font-size: 0.95em;
            }
            .cta-section h2 {
                font-size: 2em;
            }
            .cta-section p {
                font-size: 1em;
            }
        }

/* roulang page: category3 */
:root {
            --primary-color: #ff6b6b;
            --secondary-color: #4ecdc4;
            --background-color: #f8f9fa;
            --text-color: #333;
            --light-text-color: #666;
            --border-color: #e0e0e0;
            --card-background: #ffffff;
            --container-max-width: 1200px;
            --spacing-unit: 1rem;
            --rounded-corners: 8px;
            --shadow: 0 4px 12px rgba(0,0,0,0.08);
            --transition-speed: 0.3s;
        }

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

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

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

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

        a:hover {
            color: #d9534f;
        }

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

        header {
            background-color: var(--card-background);
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
            padding: calc(var(--spacing-unit) * 0.8) 0;
        }

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

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

        header ul {
            list-style: none;
            display: flex;
            gap: var(--spacing-unit);
        }

        header ul li a {
            color: var(--text-color);
            font-weight: 500;
            padding: calc(var(--spacing-unit) * 0.5) calc(var(--spacing-unit));
            border-radius: var(--rounded-corners);
            transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
        }

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

        header ul li a:not(.active):hover {
            background-color: #f0f0f0;
            color: var(--primary-color);
        }

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

        .mobile-menu {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            width: 100%;
            background-color: var(--card-background);
            box-shadow: var(--shadow);
            padding: var(--spacing-unit);
        }
        .mobile-menu ul {
            flex-direction: column;
            gap: var(--spacing-unit);
        }

        .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;
            text-align: center;
            padding: calc(var(--spacing-unit) * 5) var(--spacing-unit);
            position: relative;
            display: flex;
            justify-content: center;
            align-items: center;
        }

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

        .hero p {
            font-size: 1.2rem;
            margin-bottom: calc(var(--spacing-unit) * 2);
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

        .btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: white;
            padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2.5);
            border-radius: var(--rounded-corners);
            font-size: 1.1rem;
            font-weight: bold;
            transition: background-color var(--transition-speed) ease, transform var(--transition-speed) ease;
            border: none;
            cursor: pointer;
        }

        .btn:hover {
            background-color: #d9534f;
            transform: translateY(-2px);
        }

        .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);
        }

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

        .card {
            background-color: var(--card-background);
            border-radius: var(--rounded-corners);
            box-shadow: var(--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 24px rgba(0,0,0,0.15);
        }

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

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

        .card-content h3 {
            font-size: 1.4rem;
            margin-bottom: calc(var(--spacing-unit) * 0.8);
            color: var(--text-color);
        }

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

        .card-content .btn {
            margin-top: var(--spacing-unit);
            width: 100%;
            text-align: center;
        }

        .feature-section {
            background-color: white;
            border-radius: var(--rounded-corners);
            box-shadow: var(--shadow);
            padding: calc(var(--spacing-unit) * 3);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: calc(var(--spacing-unit) * 2);
            text-align: center;
        }

        .feature-section img {
            max-width: 80px;
            margin-bottom: var(--spacing-unit);
        }

        .feature-section h3 {
            font-size: 1.8rem;
            color: var(--primary-color);
        }

        .feature-section p {
            font-size: 1rem;
            color: var(--light-text-color);
            max-width: 600px;
        }

        .faq-section {
            background-color: var(--card-background);
            border-radius: var(--rounded-corners);
            box-shadow: var(--shadow);
            padding: calc(var(--spacing-unit) * 3);
        }

        .faq-item {
            border-bottom: 1px solid var(--border-color);
            padding: calc(var(--spacing-unit) * 1.5) 0;
        }

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

        .faq-question {
            font-size: 1.2rem;
            font-weight: bold;
            color: var(--text-color);
            cursor: pointer;
            position: relative;
            padding-left: calc(var(--spacing-unit) * 2);
        }

        .faq-question::before {
            content: '+';
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
            font-size: 1.5rem;
            color: var(--primary-color);
            transition: transform var(--transition-speed) ease;
        }

        .faq-item.open .faq-question::before {
            transform: translateY(-50%) rotate(45deg);
        }

        .faq-answer {
            font-size: 1rem;
            color: var(--light-text-color);
            max-height: 0;
            overflow: hidden;
            transition: max-height var(--transition-speed) ease-out;
            padding-left: calc(var(--spacing-unit) * 2);
            margin-top: var(--spacing-unit);
        }

        .cta-section {
            background-color: var(--primary-color);
            color: white;
            text-align: center;
            padding: calc(var(--spacing-unit) * 4) var(--spacing-unit);
        }

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

        .cta-section p {
            font-size: 1.1rem;
            margin-bottom: calc(var(--spacing-unit) * 2.5);
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

        .cta-section .btn {
            background-color: white;
            color: var(--primary-color);
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            font-size: 1.2rem;
        }

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

        footer {
            background-color: #333;
            color: white;
            padding: calc(var(--spacing-unit) * 3) 0;
            margin-top: auto; /* Pushes footer to the bottom */
        }

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

        .footer-brand, .footer-links, .footer-contact {
            grid-column: span 1;
        }

        .footer-brand {
            grid-column: span 2; /* Larger span for brand info */
        }

        .footer-logo {
            font-size: 1.8rem;
            font-weight: bold;
            margin-bottom: var(--spacing-unit);
        }

        .footer-brand p {
            font-size: 0.9rem;
            color: #bbb;
        }

        footer h4 {
            font-size: 1.2rem;
            margin-bottom: calc(var(--spacing-unit) * 1.5);
            border-bottom: 1px solid #555;
            padding-bottom: calc(var(--spacing-unit) * 0.5);
        }

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

        footer ul li {
            margin-bottom: calc(var(--spacing-unit) * 0.8);
        }

        footer ul li a {
            color: #bbb;
            font-size: 0.9rem;
            transition: color var(--transition-speed) ease;
        }

        footer ul li a:hover {
            color: white;
        }

        .footer-contact p {
            font-size: 0.9rem;
            color: #bbb;
            margin-bottom: calc(var(--spacing-unit) * 0.5);
        }

        .footer-copyright {
            text-align: center;
            padding-top: calc(var(--spacing-unit) * 2);
            margin-top: calc(var(--spacing-unit) * 3);
            border-top: 1px solid #444;
            font-size: 0.8rem;
            color: #aaa;
        }

        /* Responsive Adjustments */
        @media (max-width: 1024px) {
            .container {
                padding: 0 calc(var(--spacing-unit) * 1.5);
            }
            .logo {
                font-size: 1.6rem;
            }
            header ul {
                gap: calc(var(--spacing-unit) * 0.8);
            }
            header ul li a {
                padding: calc(var(--spacing-unit) * 0.4) calc(var(--spacing-unit) * 0.8);
            }
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero p {
                font-size: 1.1rem;
            }
            .section h2 {
                font-size: 2.2rem;
            }
            .card-content h3 {
                font-size: 1.3rem;
            }
            .card-content p {
                font-size: 0.9rem;
            }
            .cta-section h2 {
                font-size: 2.4rem;
            }
            footer .container {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-brand {
                grid-column: span 2;
            }
        }

        @media (max-width: 768px) {
            .mobile-nav-toggle {
                display: block;
            }
            header ul {
                display: none;
            }
            .mobile-menu {
                display: block;
                transform: translateX(-100%);
                transition: transform var(--transition-speed) ease;
                position: fixed;
                top: 0;
                left: 0;
                height: 100vh;
                z-index: 1001;
                width: 280px;
                padding: calc(var(--spacing-unit) * 2);
            }
            .mobile-menu.active {
                transform: translateX(0);
            }
            .mobile-menu ul {
                flex-direction: column;
                align-items: flex-start;
                gap: calc(var(--spacing-unit));
            }
             .mobile-menu ul li a {
                width: 100%;
                padding: var(--spacing-unit) 0;
            }
            .hero {
                padding: calc(var(--spacing-unit) * 4) var(--spacing-unit);
            }
            .hero h1 {
                font-size: 2rem;
            }
            .hero p {
                font-size: 1rem;
            }
            .section {
                padding: calc(var(--spacing-unit) * 3) 0;
            }
            .section h2 {
                font-size: 2rem;
            }
            .card-grid {
                grid-template-columns: 1fr;
            }
            .cta-section {
                padding: calc(var(--spacing-unit) * 3) var(--spacing-unit);
            }
            .cta-section h2 {
                font-size: 2rem;
            }
            .cta-section p {
                font-size: 1rem;
            }
            footer .container {
                grid-template-columns: 1fr;
            }
            .footer-brand, .footer-links, .footer-contact {
                grid-column: span 1;
            }
            footer h4 {
                font-size: 1.1rem;
            }
        }

/* roulang page: category4 */
:root {
            --primary-color: #d32f2f; /* 深红色 */
            --secondary-color: #f44336; /* 亮红色 */
            --accent-color: #ff9800; /* 橙色 */
            --background-color: #f8f9fa; /* 浅灰背景 */
            --text-color: #212529; /* 深灰文字 */
            --light-text-color: #6c757d; /* 浅灰文字 */
            --border-color: #dee2e6; /* 边框灰 */
            --card-background: #ffffff; /* 白色卡片背景 */
            --button-hover-bg: #e53935; /* 鼠标悬停按钮背景 */
            --button-active-bg: #c62828; /* 点击按钮背景 */
            --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
            --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
            --container-max-width: 1200px;
            --spacing-xs: 0.5rem;
            --spacing-sm: 1rem;
            --spacing-md: 1.5rem;
            --spacing-lg: 2rem;
            --spacing-xl: 3rem;
            --radius-sm: 4px;
            --radius-md: 8px;
            --radius-lg: 12px;
        }

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

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

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

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

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

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

        /* Header and Navigation */
        header {
            background-color: var(--card-background);
            box-shadow: var(--shadow-sm);
            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);
            text-transform: uppercase;
        }

        header nav ul {
            list-style: none;
            display: flex;
            gap: var(--spacing-md);
        }

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

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

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

        .mobile-menu {
            display: none;
            background-color: var(--card-background);
            width: 100%;
            text-align: center;
        }

        .mobile-menu ul {
            list-style: none;
            padding: var(--spacing-md) 0;
        }

        .mobile-menu ul li a {
            display: block;
            padding: var(--spacing-sm);
            color: var(--text-color);
        }

        .mobile-menu ul li a.active {
            background-color: var(--primary-color);
            color: var(--card-background);
        }

        /* Hero Section */
        .hero {
            background-image: url('/assets/images/backpic/back-3.webp');
            background-size: cover;
            background-position: center;
            color: #ffffff;
            text-align: center;
            padding: var(--spacing-xl) var(--spacing-sm);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            min-height: 50vh;
            position: relative;
        }

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

        .hero .hero-content {
            position: relative;
            z-index: 2;
            max-width: 800px;
        }

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

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

        .hero .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: #ffffff;
            padding: var(--spacing-sm) var(--spacing-lg);
            border-radius: var(--radius-lg);
            font-size: 1.1rem;
            font-weight: bold;
            transition: background-color 0.3s ease, transform 0.2s ease;
        }

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

        /* Main Content Sections */
        main {
            flex: 1;
            padding: var(--spacing-lg) 0;
        }

        .section {
            padding: var(--spacing-xl) 0;
        }

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

        .section-description {
            text-align: center;
            color: var(--light-text-color);
            font-size: 1.1rem;
            margin-bottom: var(--spacing-xl);
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
        }

        /* Category Focus Section */
        .category-focus {
            background-color: var(--card-background);
            border-radius: var(--radius-lg);
            padding: var(--spacing-xl) var(--spacing-md);
            box-shadow: var(--shadow-md);
            text-align: center;
        }

        .category-focus h3 {
            font-size: 2rem;
            color: var(--secondary-color);
            margin-bottom: var(--spacing-md);
        }

        .category-focus p {
            font-size: 1.1rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-lg);
        }

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

        .feature-item {
            text-align: center;
            padding: var(--spacing-md);
            background-color: var(--background-color);
            border-radius: var(--radius-md);
        }

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

        .feature-item h4 {
            font-size: 1.3rem;
            margin-bottom: var(--spacing-xs);
            color: var(--primary-color);
        }

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

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

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

        .video-card img {
            width: 100%;
            height: 200px;
            object-fit: cover;
            background-color: #e9ecef; /* Placeholder color */
        }

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

        .video-card h4 {
            font-size: 1.2rem;
            margin-bottom: var(--spacing-xs);
            color: var(--primary-color);
        }

        .video-card p {
            font-size: 0.95rem;
            color: var(--light-text-color);
            margin-bottom: var(--spacing-sm);
        }

        .video-card .play-button {
            display: inline-block;
            background-color: var(--secondary-color);
            color: #ffffff;
            padding: var(--spacing-xs) var(--spacing-md);
            border-radius: var(--radius-sm);
            text-align: center;
            font-weight: bold;
            transition: background-color 0.3s ease;
            margin-top: auto; /* Pushes button to bottom */
        }

        .video-card .play-button:hover {
            background-color: var(--button-hover-bg);
        }

        /* FAQ Section */
        .faq-section .container {
            max-width: 800px; /* Narrower for better FAQ readability */
        }

        .faq-item {
            background-color: var(--card-background);
            border-radius: var(--radius-md);
            margin-bottom: var(--spacing-sm);
            box-shadow: var(--shadow-sm);
            overflow: hidden;
        }

        .faq-item .question {
            padding: var(--spacing-md);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: bold;
            color: var(--primary-color);
            transition: background-color 0.3s ease;
        }

        .faq-item .question:hover {
            background-color: #f1f3f5;
        }

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

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

        .faq-item .answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out;
            padding: 0 var(--spacing-md); /* Initially no padding */
            background-color: var(--background-color);
            color: var(--light-text-color);
            font-size: 1rem;
        }

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

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

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

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

        .cta-section .cta-button {
            display: inline-block;
            background-color: var(--accent-color);
            color: #ffffff;
            padding: var(--spacing-sm) var(--spacing-lg);
            border-radius: var(--radius-lg);
            font-size: 1.1rem;
            font-weight: bold;
            transition: background-color 0.3s ease, transform 0.2s ease;
        }

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

        /* Footer */
        footer {
            background-color: #2c3e50; /* Dark blue/gray */
            color: #ecf0f1; /* Light gray text */
            padding: var(--spacing-xl) 0;
            margin-top: auto; /* Pushes footer to the bottom */
        }

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

        .footer-brand, .footer-links, .footer-contact {
            text-align: left;
        }

        .footer-logo {
            font-size: 1.8rem;
            font-weight: bold;
            color: var(--accent-color);
            margin-bottom: var(--spacing-sm);
        }

        .footer-brand p {
            font-size: 0.95rem;
            color: #bdc3c7;
        }

        .footer-links h4, .footer-contact h4 {
            color: var(--accent-color);
            font-size: 1.3rem;
            margin-bottom: var(--spacing-md);
            border-bottom: 1px solid var(--accent-color);
            padding-bottom: var(--spacing-xs);
        }

        .footer-links ul, .footer-contact p {
            list-style: none;
            font-size: 0.95rem;
        }

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

        .footer-links ul li a, .footer-contact p a {
            color: #ecf0f1;
            transition: color 0.3s ease;
        }

        .footer-links ul li a:hover, .footer-contact p a:hover {
            color: var(--accent-color);
        }

        .footer-copyright {
            text-align: center;
            font-size: 0.9rem;
            color: #7f8c8d;
            padding-top: var(--spacing-md);
            border-top: 1px solid #34495e;
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            .container {
                width: 95%;
            }
            .hero h1 {
                font-size: 2.5rem;
            }
            .section h2 {
                font-size: 2.2rem;
            }
        }

        @media (max-width: 768px) {
            header nav ul {
                display: none; /* Hide desktop nav */
            }
            .mobile-nav-toggle {
                display: block; /* Show mobile toggle */
            }
            .hero {
                min-height: 40vh;
            }
            .hero h1 {
                font-size: 2rem;
            }
            .hero p {
                font-size: 1.1rem;
            }
            .section h2 {
                font-size: 2rem;
            }
            .section-description {
                font-size: 1rem;
            }
            .video-showcase .card-grid {
                grid-template-columns: 1fr; /* Stack cards on small screens */
            }
            .faq-item .answer {
                font-size: 0.95rem;
            }
            .footer-content {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 520px) {
            .logo {
                font-size: 1.5rem;
            }
            .hero {
                padding: var(--spacing-lg) var(--spacing-sm);
                min-height: 35vh;
            }
            .hero h1 {
                font-size: 1.8rem;
            }
            .hero p {
                font-size: 1rem;
                margin-bottom: var(--spacing-lg);
            }
            .hero .cta-button {
                padding: var(--spacing-sm) var(--spacing-md);
                font-size: 1rem;
            }
            .section {
                padding: var(--spacing-lg) 0;
            }
            .section h2 {
                font-size: 1.8rem;
                margin-bottom: var(--spacing-md);
            }
            .category-focus {
                padding: var(--spacing-lg) var(--spacing-sm);
            }
            .category-focus h3 {
                font-size: 1.8rem;
            }
            .feature-item h4 {
                font-size: 1.1rem;
            }
            .video-card .card-content {
                padding: var(--spacing-md) var(--spacing-sm);
            }
            .video-card h4 {
                font-size: 1.1rem;
            }
            .cta-section h2 {
                font-size: 2rem;
            }
            .cta-section p {
                font-size: 1.1rem;
            }
            .cta-section .cta-button {
                padding: var(--spacing-sm) var(--spacing-md);
            }
            .footer-logo {
                font-size: 1.5rem;
            }
            .footer-links h4, .footer-contact h4 {
                font-size: 1.1rem;
            }
        }

/* roulang page: category5 */
:root {
            --primary-color: #ff4081; /* 鲜明的粉色 */
            --secondary-color: #1976d2; /* 沉稳的蓝色 */
            --background-color: #f4f7f6; /* 柔和的浅灰 */
            --text-color: #333; /* 深灰文字 */
            --weak-text-color: #777; /* 浅灰弱文本 */
            --border-color: #ddd; /* 浅灰色边框 */
            --card-bg: #fff; /* 白色卡片背景 */
            --border-radius: 8px;
            --box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            --container-width: 1200px;
            --spacing-unit: 16px;
        }

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

        body {
            font-family: '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;
        }

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

        /* Header and Navigation */
        header {
            background-color: #fff;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

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

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

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

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

        nav ul li a {
            text-decoration: none;
            color: var(--text-color);
            font-weight: 500;
            padding: calc(var(--spacing-unit) / 2) 0;
            transition: color 0.3s ease;
            position: relative;
        }

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

        nav ul li 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: 2em;
            cursor: pointer;
            color: var(--text-color);
        }

        .mobile-menu {
            display: none;
            background-color: #fff;
            padding-bottom: var(--spacing-unit);
        }

        .mobile-menu ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        .mobile-menu ul li {
            width: 100%;
            text-align: center;
            padding: var(--spacing-unit) 0;
            border-bottom: 1px solid var(--border-color);
        }

        .mobile-menu ul li:last-child {
            border-bottom: none;
        }

        .mobile-menu ul li a {
            text-decoration: none;
            color: var(--text-color);
            font-size: 1.1em;
            display: block;
            padding: var(--spacing-unit) 0;
        }
        .mobile-menu ul li a.active {
             color: var(--primary-color);
             font-weight: bold;
        }

        /* Hero Section */
        .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) * 5) var(--spacing-unit);
            position: relative;
        }

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

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

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

        .hero p {
            font-size: 1.4em;
            max-width: 800px;
            margin: 0 auto var(--spacing-unit);
        }

        .hero .btn {
            background-color: var(--primary-color);
            color: #fff;
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            border: none;
            border-radius: var(--border-radius);
            font-size: 1.2em;
            font-weight: bold;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease;
            text-decoration: none;
            display: inline-block;
        }

        .hero .btn:hover {
            background-color: #e00062;
            transform: translateY(-2px);
        }

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

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

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

        .card {
            background-color: var(--card-bg);
            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(-5px);
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
        }

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

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

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

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

        .card-content .btn-secondary {
            background-color: var(--secondary-color);
            color: #fff;
            padding: calc(var(--spacing-unit) * 0.8) calc(var(--spacing-unit) * 1.5);
            border: none;
            border-radius: var(--border-radius);
            font-weight: bold;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease;
            text-decoration: none;
            display: inline-block;
            margin-top: auto; /* Push button to bottom */
        }

        .card-content .btn-secondary:hover {
            background-color: #0b56a3;
            transform: translateY(-2px);
        }

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

        .feature-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: calc(var(--spacing-unit) * 3);
        }

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

        .feature-item i {
            font-size: 3em;
            color: var(--secondary-color);
            margin-bottom: var(--spacing-unit);
        }

        .feature-item h3 {
            font-size: 1.3em;
            margin-bottom: calc(var(--spacing-unit) / 2);
        }

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

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

        .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;
            margin-bottom: 0;
        }

        .faq-question {
            font-size: 1.2em;
            font-weight: 600;
            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: 1.5em;
            transition: transform 0.3s ease;
        }

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

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

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

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

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

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

        .cta-section .btn {
            background-color: #fff;
            color: var(--primary-color);
            padding: calc(var(--spacing-unit) * 1.2) calc(var(--spacing-unit) * 3);
            font-size: 1.2em;
            font-weight: bold;
            border: none;
            border-radius: var(--border-radius);
            cursor: pointer;
            transition: background-color 0.3s ease, color 0.3s ease, transform 0.2s ease;
            text-decoration: none;
        }

        .cta-section .btn:hover {
            background-color: #eee;
            color: #e00062;
            transform: translateY(-2px);
        }

        /* Footer */
        footer {
            background-color: #333;
            color: #bbb;
            padding: calc(var(--spacing-unit) * 5) 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);
            margin-bottom: calc(var(--spacing-unit) * 3);
        }

        .footer-brand,
        .footer-links,
        .footer-contact {
            flex-direction: column;
        }

        .footer-logo {
            font-size: 2em;
            font-weight: bold;
            color: var(--primary-color);
            margin-bottom: var(--spacing-unit);
        }

        .footer-links h4,
        .footer-contact h4 {
            font-size: 1.4em;
            color: #fff;
            margin-bottom: var(--spacing-unit);
        }

        .footer-links ul,
        .footer-contact p {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .footer-links ul li {
            margin-bottom: calc(var(--spacing-unit) / 2);
        }

        .footer-links ul li a,
        .footer-contact p {
            color: #bbb;
            text-decoration: none;
            transition: color 0.3s ease;
        }

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

        .footer-copyright {
            text-align: center;
            padding-top: var(--spacing-unit);
            border-top: 1px solid #444;
            font-size: 0.9em;
        }

        /* Responsive Design */
        @media (max-width: 992px) {
            .container {
                width: 95%;
            }

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

            .hero p {
                font-size: 1.2em;
            }

            section h2 {
                font-size: 2em;
            }

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

        @media (max-width: 768px) {
            nav ul {
                display: none; /* Hide desktop nav */
            }

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

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

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

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

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

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

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

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

        @media (max-width: 576px) {
            .hero {
                padding: calc(var(--spacing-unit) * 3) var(--spacing-unit);
            }

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

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

            .hero .btn {
                padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
                font-size: 1em;
            }

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

            section h2 {
                font-size: 1.8em;
                margin-bottom: calc(var(--spacing-unit) * 2);
            }

            .cta-section h2 {
                font-size: 2em;
            }
            .cta-section p {
                font-size: 1em;
            }
            .cta-section .btn {
                padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
                font-size: 1em;
            }
        }