/* roulang page: index */
/* ===== Design Variables ===== */
        :root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --primary-light: #dbeafe;
            --secondary: #f59e0b;
            --secondary-dark: #d97706;
            --accent: #8b5cf6;
            --bg: #f8fafc;
            --bg-white: #ffffff;
            --bg-gray: #f1f5f9;
            --bg-dark: #0f172a;
            --text-primary: #1e293b;
            --text-secondary: #475569;
            --text-muted: #94a3b8;
            --text-light: #ffffff;
            --border: #e2e8f0;
            --border-light: #f1f5f9;
            --radius: 12px;
            --radius-sm: 8px;
            --radius-lg: 20px;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
            --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
            --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.10), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
            --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            --spacing-section: 5rem;
            --spacing-block: 3rem;
            --transition: all 0.25s ease;
        }

        /* ===== Base Reset ===== */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }
        body {
            margin: 0;
            padding: 0;
            font-family: var(--font-sans);
            font-size: 1rem;
            line-height: 1.7;
            color: var(--text-primary);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        a {
            color: var(--primary);
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--primary-dark);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button,
        input,
        textarea {
            font-family: inherit;
            font-size: inherit;
        }
        ul,
        ol {
            padding-left: 1.25rem;
        }
        h1,
        h2,
        h3,
        h4,
        h5,
        h6 {
            font-weight: 700;
            line-height: 1.3;
            color: var(--text-primary);
            margin-top: 0;
        }
        p {
            margin-top: 0;
            color: var(--text-secondary);
        }

        /* ===== Container ===== */
        .container {
            max-width: 1200px;
            padding-left: 1.25rem;
            padding-right: 1.25rem;
            margin-left: auto;
            margin-right: auto;
        }
        .container-narrow {
            max-width: 820px;
        }
        .container-wide {
            max-width: 1400px;
        }

        /* ===== Section Spacing ===== */
        .section-padding {
            padding-top: var(--spacing-section);
            padding-bottom: var(--spacing-section);
        }
        .section-padding-top {
            padding-top: var(--spacing-section);
        }
        .section-padding-bottom {
            padding-bottom: var(--spacing-section);
        }
        .section-title {
            font-size: 2.25rem;
            font-weight: 800;
            margin-bottom: 0.75rem;
            letter-spacing: -0.02em;
        }
        .section-subtitle {
            font-size: 1.1rem;
            color: var(--text-secondary);
            max-width: 640px;
            margin-bottom: 2.5rem;
        }
        .section-divider {
            width: 60px;
            height: 4px;
            background: var(--primary);
            border-radius: 4px;
            margin-bottom: 1.5rem;
        }
        .text-center .section-divider {
            margin-left: auto;
            margin-right: auto;
        }

        /* ===== Buttons ===== */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            padding: 0.7rem 1.75rem;
            font-weight: 600;
            font-size: 0.95rem;
            border-radius: var(--radius-sm);
            border: 2px solid transparent;
            transition: var(--transition);
            cursor: pointer;
            line-height: 1.4;
            text-align: center;
        }
        .btn:focus-visible {
            outline: 3px solid var(--primary);
            outline-offset: 2px;
        }
        .btn-primary {
            background: var(--primary);
            color: #fff;
            border-color: var(--primary);
        }
        .btn-primary:hover {
            background: var(--primary-dark);
            border-color: var(--primary-dark);
            color: #fff;
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }
        .btn-secondary {
            background: var(--secondary);
            color: #fff;
            border-color: var(--secondary);
        }
        .btn-secondary:hover {
            background: var(--secondary-dark);
            border-color: var(--secondary-dark);
            color: #fff;
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }
        .btn-outline-primary {
            background: transparent;
            color: var(--primary);
            border-color: var(--primary);
        }
        .btn-outline-primary:hover {
            background: var(--primary);
            color: #fff;
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }
        .btn-outline-light {
            background: transparent;
            color: #fff;
            border-color: rgba(255, 255, 255, 0.5);
        }
        .btn-outline-light:hover {
            background: rgba(255, 255, 255, 0.15);
            border-color: #fff;
            color: #fff;
            transform: translateY(-2px);
        }
        .btn-lg {
            padding: 0.9rem 2.5rem;
            font-size: 1.05rem;
            border-radius: var(--radius);
        }
        .btn-sm {
            padding: 0.45rem 1.1rem;
            font-size: 0.85rem;
        }
        .btn-ghost {
            background: transparent;
            color: var(--text-secondary);
            border-color: transparent;
        }
        .btn-ghost:hover {
            background: var(--bg-gray);
            color: var(--text-primary);
        }

        /* ===== Badge / Tag ===== */
        .badge {
            display: inline-block;
            padding: 0.25rem 0.85rem;
            font-size: 0.78rem;
            font-weight: 600;
            border-radius: 50px;
            background: var(--primary-light);
            color: var(--primary);
            letter-spacing: 0.02em;
        }
        .badge-secondary {
            background: #fef3c7;
            color: var(--secondary-dark);
        }
        .badge-accent {
            background: #ede9fe;
            color: var(--accent);
        }
        .badge-success {
            background: #dcfce7;
            color: #16a34a;
        }
        .tag {
            display: inline-block;
            padding: 0.2rem 0.75rem;
            font-size: 0.75rem;
            font-weight: 500;
            border-radius: 50px;
            background: var(--bg-gray);
            color: var(--text-secondary);
            transition: var(--transition);
        }
        .tag:hover {
            background: var(--primary-light);
            color: var(--primary);
        }

        /* ===== Card ===== */
        .card {
            background: var(--bg-white);
            border-radius: var(--radius);
            border: 1px solid var(--border);
            box-shadow: var(--shadow-sm);
            transition: var(--transition);
            overflow: hidden;
        }
        .card:hover {
            box-shadow: var(--shadow-md);
            transform: translateY(-3px);
        }
        .card-body {
            padding: 1.75rem;
        }
        .card-image {
            width: 100%;
            aspect-ratio: 16 / 9;
            object-fit: cover;
            display: block;
        }
        .card-title {
            font-size: 1.15rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }
        .card-text {
            font-size: 0.92rem;
            color: var(--text-secondary);
            margin-bottom: 1rem;
        }
        .card-footer {
            padding: 1rem 1.75rem;
            border-top: 1px solid var(--border-light);
            background: var(--bg);
        }

        /* ===== Navigation ===== */
        .site-header {
            background: var(--bg-white);
            border-bottom: 1px solid var(--border);
            box-shadow: var(--shadow-sm);
            position: sticky;
            top: 0;
            z-index: 1040;
            transition: var(--transition);
        }
        .site-header .navbar {
            padding-top: 0.6rem;
            padding-bottom: 0.6rem;
        }
        .site-header .navbar-brand {
            font-size: 1.35rem;
            font-weight: 800;
            color: var(--text-primary);
            letter-spacing: -0.02em;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .site-header .navbar-brand i {
            color: var(--primary);
            font-size: 1.6rem;
        }
        .site-header .navbar-brand:hover {
            color: var(--primary);
        }
        .site-header .nav-link {
            font-weight: 500;
            color: var(--text-secondary) !important;
            padding: 0.5rem 1rem !important;
            border-radius: var(--radius-sm);
            transition: var(--transition);
            font-size: 0.95rem;
        }
        .site-header .nav-link:hover {
            color: var(--primary) !important;
            background: var(--primary-light);
        }
        .site-header .nav-link.active {
            color: var(--primary) !important;
            background: var(--primary-light);
            font-weight: 600;
        }
        .site-header .nav-cta {
            background: var(--primary);
            color: #fff !important;
            padding: 0.5rem 1.5rem !important;
            border-radius: 50px;
            font-weight: 600;
        }
        .site-header .nav-cta:hover {
            background: var(--primary-dark) !important;
            color: #fff !important;
            transform: translateY(-1px);
            box-shadow: var(--shadow-sm);
        }
        .site-header .search-box {
            display: flex;
            align-items: center;
            background: var(--bg-gray);
            border-radius: 50px;
            padding: 0.3rem 0.3rem 0.3rem 1rem;
            border: 1px solid var(--border);
            transition: var(--transition);
            max-width: 220px;
        }
        .site-header .search-box:focus-within {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }
        .site-header .search-box input {
            border: none;
            background: transparent;
            padding: 0.4rem 0;
            font-size: 0.88rem;
            color: var(--text-primary);
            outline: none;
            flex: 1;
            min-width: 0;
        }
        .site-header .search-box input::placeholder {
            color: var(--text-muted);
        }
        .site-header .search-box button {
            background: var(--primary);
            color: #fff;
            border: none;
            border-radius: 50px;
            width: 32px;
            height: 32px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: var(--transition);
        }
        .site-header .search-box button:hover {
            background: var(--primary-dark);
        }
        .navbar-toggler {
            border: none !important;
            padding: 0.5rem !important;
            color: var(--text-primary) !important;
            font-size: 1.4rem;
        }
        .navbar-toggler:focus {
            box-shadow: none !important;
        }

        /* ===== Hero ===== */
        .hero {
            background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
            color: #fff;
            padding: 6rem 0 5rem;
            position: relative;
            overflow: hidden;
        }
        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
            pointer-events: none;
        }
        .hero .container {
            position: relative;
            z-index: 1;
        }
        .hero-badge {
            display: inline-block;
            padding: 0.3rem 1.2rem;
            background: rgba(255, 255, 255, 0.12);
            border: 1px solid rgba(255, 255, 255, 0.15);
            border-radius: 50px;
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.85);
            margin-bottom: 1.5rem;
            backdrop-filter: blur(4px);
        }
        .hero-title {
            font-size: 3.2rem;
            font-weight: 800;
            line-height: 1.15;
            margin-bottom: 1.25rem;
            letter-spacing: -0.02em;
            color: #fff;
        }
        .hero-title span {
            color: var(--secondary);
        }
        .hero-text {
            font-size: 1.15rem;
            color: rgba(255, 255, 255, 0.75);
            max-width: 560px;
            margin-bottom: 2rem;
            line-height: 1.7;
        }
        .hero-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
            align-items: center;
        }
        .hero-stats {
            display: flex;
            flex-wrap: wrap;
            gap: 2.5rem;
            margin-top: 3rem;
            padding-top: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }
        .hero-stat-number {
            font-size: 1.8rem;
            font-weight: 800;
            color: #fff;
            line-height: 1.2;
        }
        .hero-stat-label {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.6);
        }

        /* ===== Feature / Intro ===== */
        .intro-section {
            background: var(--bg-white);
        }
        .intro-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 3rem;
            align-items: center;
        }
        .intro-image-wrapper {
            background: var(--bg-gray);
            border-radius: var(--radius-lg);
            overflow: hidden;
            aspect-ratio: 4 / 3;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-muted);
            font-size: 3rem;
            border: 1px solid var(--border);
        }
        .intro-image-wrapper i {
            opacity: 0.4;
        }
        .intro-content .badge {
            margin-bottom: 0.75rem;
        }
        .intro-content h2 {
            font-size: 2rem;
            font-weight: 800;
            margin-bottom: 1rem;
        }
        .intro-features {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1rem;
            margin-top: 1.5rem;
        }
        .intro-feature-item {
            display: flex;
            align-items: flex-start;
            gap: 0.75rem;
            padding: 1rem;
            background: var(--bg);
            border-radius: var(--radius-sm);
            border: 1px solid var(--border-light);
        }
        .intro-feature-item i {
            color: var(--primary);
            font-size: 1.2rem;
            margin-top: 0.1rem;
            flex-shrink: 0;
        }
        .intro-feature-item h4 {
            font-size: 0.95rem;
            font-weight: 600;
            margin-bottom: 0.2rem;
        }
        .intro-feature-item p {
            font-size: 0.85rem;
            color: var(--text-secondary);
            margin-bottom: 0;
        }

        /* ===== Category Section ===== */
        .category-section {
            background: var(--bg);
        }
        .category-card {
            background: var(--bg-white);
            border-radius: var(--radius);
            border: 1px solid var(--border);
            padding: 2rem 1.75rem;
            text-align: center;
            transition: var(--transition);
            box-shadow: var(--shadow-sm);
            height: 100%;
        }
        .category-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
            border-color: var(--primary-light);
        }
        .category-icon {
            width: 64px;
            height: 64px;
            margin: 0 auto 1.25rem;
            background: var(--primary-light);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.6rem;
            color: var(--primary);
            transition: var(--transition);
        }
        .category-card:hover .category-icon {
            background: var(--primary);
            color: #fff;
        }
        .category-card h3 {
            font-size: 1.15rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }
        .category-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            margin-bottom: 0;
        }
        .category-card .btn {
            margin-top: 1.25rem;
        }

        /* ===== Latest Posts / CMS List ===== */
        .posts-section {
            background: var(--bg-white);
        }
        .post-card {
            display: flex;
            gap: 1.5rem;
            padding: 1.5rem 0;
            border-bottom: 1px solid var(--border-light);
            transition: var(--transition);
        }
        .post-card:last-child {
            border-bottom: none;
        }
        .post-card:hover {
            padding-left: 0.5rem;
        }
        .post-thumb {
            width: 120px;
            height: 90px;
            border-radius: var(--radius-sm);
            background: var(--bg-gray);
            flex-shrink: 0;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-muted);
            font-size: 1.5rem;
            overflow: hidden;
            border: 1px solid var(--border-light);
        }
        .post-thumb img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .post-info {
            flex: 1;
            min-width: 0;
        }
        .post-info .badge {
            margin-bottom: 0.4rem;
        }
        .post-info h3 {
            font-size: 1.05rem;
            font-weight: 700;
            margin-bottom: 0.4rem;
        }
        .post-info h3 a {
            color: var(--text-primary);
        }
        .post-info h3 a:hover {
            color: var(--primary);
        }
        .post-info p {
            font-size: 0.88rem;
            color: var(--text-secondary);
            margin-bottom: 0.5rem;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .post-meta {
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
            font-size: 0.82rem;
            color: var(--text-muted);
        }
        .post-meta i {
            margin-right: 0.3rem;
        }
        .empty-posts {
            text-align: center;
            padding: 3rem 1rem;
            color: var(--text-muted);
            background: var(--bg);
            border-radius: var(--radius);
            border: 1px dashed var(--border);
        }
        .empty-posts i {
            font-size: 2.5rem;
            margin-bottom: 1rem;
            opacity: 0.5;
        }

        /* ===== Stats / Data ===== */
        .stats-section {
            background: var(--bg-dark);
            color: #fff;
        }
        .stats-section .section-title {
            color: #fff;
        }
        .stats-section .section-subtitle {
            color: rgba(255, 255, 255, 0.65);
        }
        .stat-item {
            text-align: center;
            padding: 2rem 1rem;
        }
        .stat-number {
            font-size: 2.8rem;
            font-weight: 800;
            color: #fff;
            line-height: 1.2;
            letter-spacing: -0.02em;
        }
        .stat-number .stat-suffix {
            font-size: 1.6rem;
            color: var(--secondary);
        }
        .stat-label {
            font-size: 0.95rem;
            color: rgba(255, 255, 255, 0.65);
            margin-top: 0.4rem;
        }
        .stat-icon {
            font-size: 1.8rem;
            color: var(--secondary);
            margin-bottom: 0.75rem;
        }

        /* ===== Process / Steps ===== */
        .process-section {
            background: var(--bg);
        }
        .step-card {
            text-align: center;
            padding: 2rem 1.5rem;
            background: var(--bg-white);
            border-radius: var(--radius);
            border: 1px solid var(--border);
            box-shadow: var(--shadow-sm);
            transition: var(--transition);
            height: 100%;
            position: relative;
        }
        .step-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
        }
        .step-number {
            width: 48px;
            height: 48px;
            margin: 0 auto 1.25rem;
            background: var(--primary);
            color: #fff;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            font-weight: 700;
        }
        .step-card h3 {
            font-size: 1.1rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }
        .step-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            margin-bottom: 0;
        }
        .step-connector {
            display: none;
        }
        @media (min-width: 768px) {
            .step-connector {
                display: flex;
                align-items: center;
                justify-content: center;
                color: var(--text-muted);
                font-size: 1.5rem;
                position: absolute;
                right: -1.25rem;
                top: 50%;
                transform: translateY(-50%);
                z-index: 2;
            }
        }

        /* ===== FAQ ===== */
        .faq-section {
            background: var(--bg-white);
        }
        .faq-item {
            border: 1px solid var(--border);
            border-radius: var(--radius-sm);
            margin-bottom: 0.75rem;
            overflow: hidden;
            transition: var(--transition);
        }
        .faq-item:hover {
            border-color: var(--primary-light);
        }
        .faq-question {
            width: 100%;
            background: var(--bg);
            border: none;
            padding: 1.1rem 1.5rem;
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-primary);
            text-align: left;
            display: flex;
            justify-content: space-between;
            align-items: center;
            cursor: pointer;
            transition: var(--transition);
        }
        .faq-question:hover {
            background: var(--primary-light);
        }
        .faq-question i {
            transition: var(--transition);
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        .faq-question[aria-expanded="true"] i {
            transform: rotate(180deg);
            color: var(--primary);
        }
        .faq-answer {
            padding: 0 1.5rem 1.25rem;
            font-size: 0.95rem;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        .faq-answer p:last-child {
            margin-bottom: 0;
        }

        /* ===== CTA ===== */
        .cta-section {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            color: #fff;
            text-align: center;
            padding: 4.5rem 0;
        }
        .cta-section .section-title {
            color: #fff;
            font-size: 2.2rem;
        }
        .cta-section .section-subtitle {
            color: rgba(255, 255, 255, 0.8);
            margin-left: auto;
            margin-right: auto;
        }
        .cta-section .btn {
            background: #fff;
            color: var(--primary);
            border-color: #fff;
            font-weight: 700;
        }
        .cta-section .btn:hover {
            background: var(--secondary);
            color: #fff;
            border-color: var(--secondary);
            transform: translateY(-3px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
        }
        .cta-section .btn-outline-light {
            background: transparent;
            color: #fff;
            border-color: rgba(255, 255, 255, 0.4);
        }
        .cta-section .btn-outline-light:hover {
            background: rgba(255, 255, 255, 0.15);
            border-color: #fff;
            color: #fff;
        }

        /* ===== Footer ===== */
        .site-footer {
            background: var(--bg-dark);
            color: rgba(255, 255, 255, 0.75);
            padding: 3.5rem 0 2rem;
        }
        .site-footer h5 {
            color: #fff;
            font-weight: 700;
            font-size: 1rem;
            margin-bottom: 1.25rem;
        }
        .site-footer a {
            color: rgba(255, 255, 255, 0.65);
            font-size: 0.9rem;
            transition: var(--transition);
        }
        .site-footer a:hover {
            color: #fff;
            text-decoration: underline;
        }
        .site-footer .footer-logo {
            font-size: 1.3rem;
            font-weight: 800;
            color: #fff;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            margin-bottom: 0.75rem;
        }
        .site-footer .footer-logo i {
            color: var(--secondary);
        }
        .site-footer .footer-desc {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.55);
            max-width: 320px;
        }
        .site-footer .footer-links {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        .site-footer .footer-links li {
            margin-bottom: 0.5rem;
        }
        .site-footer .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.08);
            padding-top: 1.5rem;
            margin-top: 2.5rem;
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.45);
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 0.5rem;
        }

        /* ===== Breadcrumb ===== */
        .breadcrumb-nav {
            padding: 0.75rem 0;
            background: var(--bg);
            border-bottom: 1px solid var(--border-light);
        }
        .breadcrumb-nav .breadcrumb {
            margin-bottom: 0;
            font-size: 0.88rem;
        }
        .breadcrumb-nav .breadcrumb-item a {
            color: var(--text-secondary);
        }
        .breadcrumb-nav .breadcrumb-item.active {
            color: var(--text-muted);
        }

        /* ===== Back to Top ===== */
        .back-to-top {
            position: fixed;
            bottom: 2rem;
            right: 2rem;
            width: 44px;
            height: 44px;
            background: var(--primary);
            color: #fff;
            border: none;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.1rem;
            box-shadow: var(--shadow-md);
            cursor: pointer;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 1050;
        }
        .back-to-top.show {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--primary-dark);
            transform: translateY(-3px);
            box-shadow: var(--shadow-lg);
        }

        /* ===== Responsive ===== */
        @media (max-width: 1024px) {
            .hero-title {
                font-size: 2.6rem;
            }
            .intro-grid {
                gap: 2rem;
            }
            .section-title {
                font-size: 1.9rem;
            }
        }
        @media (max-width: 768px) {
            :root {
                --spacing-section: 3.5rem;
            }
            .site-header .navbar-brand {
                font-size: 1.15rem;
            }
            .site-header .navbar-brand i {
                font-size: 1.3rem;
            }
            .site-header .search-box {
                max-width: 100%;
                margin-top: 0.5rem;
            }
            .navbar-collapse {
                padding-top: 0.75rem;
            }
            .hero {
                padding: 4rem 0 3rem;
            }
            .hero-title {
                font-size: 2rem;
            }
            .hero-text {
                font-size: 1rem;
            }
            .hero-stats {
                gap: 1.5rem;
                margin-top: 2rem;
                padding-top: 1.5rem;
            }
            .hero-stat-number {
                font-size: 1.4rem;
            }
            .intro-grid {
                grid-template-columns: 1fr;
                gap: 1.5rem;
            }
            .intro-features {
                grid-template-columns: 1fr;
            }
            .intro-image-wrapper {
                aspect-ratio: 16 / 9;
                order: -1;
            }
            .section-title {
                font-size: 1.6rem;
            }
            .section-subtitle {
                font-size: 1rem;
            }
            .stat-number {
                font-size: 2.2rem;
            }
            .post-card {
                flex-direction: column;
                gap: 0.75rem;
            }
            .post-thumb {
                width: 100%;
                height: 160px;
            }
            .post-info h3 {
                font-size: 1rem;
            }
            .category-card {
                padding: 1.5rem 1.25rem;
            }
            .cta-section {
                padding: 3rem 0;
            }
            .cta-section .section-title {
                font-size: 1.6rem;
            }
            .site-footer .footer-logo {
                font-size: 1.1rem;
            }
            .back-to-top {
                bottom: 1.25rem;
                right: 1.25rem;
                width: 38px;
                height: 38px;
                font-size: 0.95rem;
            }
        }
        @media (max-width: 520px) {
            .hero-title {
                font-size: 1.6rem;
            }
            .hero-actions {
                flex-direction: column;
                align-items: stretch;
            }
            .hero-actions .btn {
                width: 100%;
            }
            .hero-stats {
                flex-direction: column;
                gap: 1rem;
            }
            .section-title {
                font-size: 1.35rem;
            }
            .stat-number {
                font-size: 1.8rem;
            }
            .post-thumb {
                height: 120px;
            }
            .post-meta {
                font-size: 0.78rem;
                gap: 0.6rem;
            }
            .faq-question {
                font-size: 0.92rem;
                padding: 0.9rem 1.1rem;
            }
            .faq-answer {
                padding: 0 1.1rem 1rem;
                font-size: 0.88rem;
            }
            .site-footer .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
        }

        /* ===== Utility ===== */
        .text-primary {
            color: var(--primary) !important;
        }
        .text-secondary {
            color: var(--text-secondary) !important;
        }
        .bg-primary-light {
            background: var(--primary-light) !important;
        }
        .gap-1 {
            gap: 0.5rem;
        }
        .gap-2 {
            gap: 1rem;
        }
        .gap-3 {
            gap: 1.5rem;
        }
        .mt-1 {
            margin-top: 0.5rem;
        }
        .mt-2 {
            margin-top: 1rem;
        }
        .mt-3 {
            margin-top: 1.5rem;
        }
        .mb-1 {
            margin-bottom: 0.5rem;
        }
        .mb-2 {
            margin-bottom: 1rem;
        }
        .mb-3 {
            margin-bottom: 1.5rem;
        }
        .fw-600 {
            font-weight: 600;
        }
        .fw-700 {
            font-weight: 700;
        }
        .fw-800 {
            font-weight: 800;
        }
        .rounded-full {
            border-radius: 50px;
        }
        .shadow-hover:hover {
            box-shadow: var(--shadow-md);
            transform: translateY(-2px);
        }
        .transition {
            transition: var(--transition);
        }

/* roulang page: article */
:root {
            --primary: #6C3CF8;
            --primary-dark: #5228D0;
            --primary-light: #8B6CF8;
            --secondary: #FF6B35;
            --secondary-light: #FF8C5A;
            --accent: #00D4AA;
            --bg-white: #FFFFFF;
            --bg-light: #F5F7FC;
            --bg-dark: #0F0E1A;
            --text-dark: #1A1A2E;
            --text-muted: #6B7280;
            --text-light: #9CA3AF;
            --border-color: #E5E7EB;
            --border-light: #F0F0F5;
            --radius-sm: 8px;
            --radius-md: 14px;
            --radius-lg: 20px;
            --radius-xl: 28px;
            --shadow-sm: 0 2px 8px rgba(108, 60, 248, 0.06);
            --shadow-md: 0 8px 30px rgba(108, 60, 248, 0.10);
            --shadow-lg: 0 20px 60px rgba(108, 60, 248, 0.15);
            --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            margin: 0;
            padding: 0;
            font-family: var(--font-sans);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text-dark);
            background: var(--bg-light);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        a {
            color: var(--primary);
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--primary-dark);
        }
        a:focus-visible {
            outline: 3px solid var(--primary-light);
            outline-offset: 2px;
            border-radius: 4px;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
            border-radius: var(--radius-sm);
        }

        button,
        input,
        select,
        textarea {
            font-family: inherit;
            font-size: inherit;
        }
        button:focus-visible,
        input:focus-visible {
            outline: 3px solid var(--primary-light);
            outline-offset: 2px;
        }

        .container {
            max-width: 1200px;
            padding-left: 20px;
            padding-right: 20px;
        }

        /* ===== Header ===== */
        .site-header {
            background: var(--bg-white);
            border-bottom: 1px solid var(--border-light);
            box-shadow: var(--shadow-sm);
            position: sticky;
            top: 0;
            z-index: 1050;
            backdrop-filter: blur(12px);
            background: rgba(255, 255, 255, 0.96);
        }
        .site-header .navbar {
            padding-top: 12px;
            padding-bottom: 12px;
        }
        .site-header .navbar-brand {
            font-weight: 800;
            font-size: 1.35rem;
            color: var(--text-dark);
            letter-spacing: -0.3px;
            display: flex;
            align-items: center;
            gap: 10px;
            transition: var(--transition);
        }
        .site-header .navbar-brand i {
            color: var(--primary);
            font-size: 1.6rem;
        }
        .site-header .navbar-brand:hover {
            color: var(--primary);
            transform: translateY(-1px);
        }
        .site-header .navbar-nav .nav-link {
            font-weight: 600;
            font-size: 0.95rem;
            color: var(--text-muted);
            padding: 8px 18px;
            border-radius: var(--radius-sm);
            transition: var(--transition);
            position: relative;
        }
        .site-header .navbar-nav .nav-link:hover {
            color: var(--primary);
            background: rgba(108, 60, 248, 0.06);
        }
        .site-header .navbar-nav .nav-link.active {
            color: var(--primary);
            background: rgba(108, 60, 248, 0.10);
        }
        .site-header .navbar-nav .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 50%;
            transform: translateX(-50%);
            width: 20px;
            height: 3px;
            background: var(--primary);
            border-radius: 6px;
        }
        .search-box {
            display: flex;
            align-items: center;
            background: var(--bg-light);
            border-radius: 50px;
            padding: 2px 2px 2px 16px;
            border: 1px solid var(--border-color);
            transition: var(--transition);
        }
        .search-box:focus-within {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(108, 60, 248, 0.12);
        }
        .search-box input {
            border: none;
            background: transparent;
            padding: 8px 0;
            font-size: 0.9rem;
            color: var(--text-dark);
            width: 140px;
            outline: none;
        }
        .search-box input::placeholder {
            color: var(--text-light);
        }
        .search-box button {
            border: none;
            background: var(--primary);
            color: #fff;
            width: 36px;
            height: 36px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: var(--transition);
        }
        .search-box button:hover {
            background: var(--primary-dark);
            transform: scale(1.05);
        }
        .nav-cta {
            background: var(--secondary);
            border: none;
            border-radius: 50px;
            padding: 10px 24px;
            font-weight: 700;
            font-size: 0.9rem;
            color: #fff;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            gap: 8px;
            box-shadow: 0 4px 14px rgba(255, 107, 53, 0.30);
        }
        .nav-cta:hover {
            background: #E55A2B;
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(255, 107, 53, 0.40);
            color: #fff;
        }
        .navbar-toggler {
            border: none;
            color: var(--text-dark);
            font-size: 1.4rem;
            padding: 6px 10px;
            border-radius: var(--radius-sm);
            background: var(--bg-light);
        }
        .navbar-toggler:hover {
            background: var(--border-color);
        }

        /* ===== Article Hero ===== */
        .article-hero {
            padding: 40px 0 30px;
            background: var(--bg-white);
            border-bottom: 1px solid var(--border-light);
        }
        .article-hero .breadcrumb {
            background: transparent;
            padding: 0;
            margin-bottom: 16px;
            font-size: 0.85rem;
            font-weight: 500;
        }
        .article-hero .breadcrumb-item a {
            color: var(--text-muted);
            transition: var(--transition);
        }
        .article-hero .breadcrumb-item a:hover {
            color: var(--primary);
        }
        .article-hero .breadcrumb-item.active {
            color: var(--text-light);
        }
        .article-hero .breadcrumb-item+.breadcrumb-item::before {
            color: var(--text-light);
        }
        .article-hero .category-badge {
            display: inline-block;
            background: rgba(108, 60, 248, 0.10);
            color: var(--primary);
            font-weight: 700;
            font-size: 0.8rem;
            padding: 4px 16px;
            border-radius: 50px;
            margin-bottom: 12px;
            letter-spacing: 0.3px;
        }
        .article-hero h1 {
            font-size: 2.2rem;
            font-weight: 800;
            line-height: 1.3;
            color: var(--text-dark);
            margin-bottom: 16px;
            letter-spacing: -0.5px;
        }
        .article-hero .meta-info {
            display: flex;
            flex-wrap: wrap;
            gap: 18px;
            font-size: 0.9rem;
            color: var(--text-muted);
        }
        .article-hero .meta-info i {
            margin-right: 6px;
            color: var(--primary-light);
        }
        .article-hero .meta-info span {
            display: inline-flex;
            align-items: center;
        }

        /* ===== Article Content ===== */
        .article-content-wrap {
            padding: 40px 0 50px;
            background: var(--bg-white);
        }
        .article-content {
            max-width: 800px;
            margin: 0 auto;
        }
        .article-content .content-body {
            font-size: 1.05rem;
            line-height: 1.85;
            color: var(--text-dark);
        }
        .article-content .content-body p {
            margin-bottom: 1.4rem;
        }
        .article-content .content-body h2,
        .article-content .content-body h3 {
            font-weight: 700;
            margin-top: 2rem;
            margin-bottom: 1rem;
            color: var(--text-dark);
        }
        .article-content .content-body h2 {
            font-size: 1.6rem;
        }
        .article-content .content-body h3 {
            font-size: 1.3rem;
        }
        .article-content .content-body img {
            border-radius: var(--radius-md);
            margin: 1.5rem auto;
            box-shadow: var(--shadow-sm);
        }
        .article-content .content-body ul,
        .article-content .content-body ol {
            padding-left: 1.5rem;
            margin-bottom: 1.4rem;
        }
        .article-content .content-body li {
            margin-bottom: 0.4rem;
        }
        .article-content .content-body blockquote {
            border-left: 4px solid var(--primary);
            padding: 12px 20px;
            margin: 1.5rem 0;
            background: var(--bg-light);
            border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
            color: var(--text-muted);
            font-style: italic;
        }
        .article-content .content-body a {
            color: var(--primary);
            text-decoration: underline;
            text-underline-offset: 2px;
        }
        .article-content .content-body a:hover {
            color: var(--primary-dark);
        }
        .article-content .tag-list {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            margin-top: 36px;
            padding-top: 28px;
            border-top: 1px solid var(--border-light);
        }
        .article-content .tag-list .tag {
            background: var(--bg-light);
            color: var(--text-muted);
            font-size: 0.82rem;
            font-weight: 600;
            padding: 6px 18px;
            border-radius: 50px;
            transition: var(--transition);
        }
        .article-content .tag-list .tag:hover {
            background: var(--primary);
            color: #fff;
            transform: translateY(-1px);
        }

        /* ===== Post Navigation ===== */
        .post-nav {
            padding: 30px 0;
            background: var(--bg-light);
        }
        .post-nav .post-nav-link {
            display: flex;
            align-items: center;
            gap: 14px;
            padding: 16px 22px;
            background: var(--bg-white);
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-sm);
            transition: var(--transition);
            height: 100%;
        }
        .post-nav .post-nav-link:hover {
            box-shadow: var(--shadow-md);
            transform: translateY(-2px);
        }
        .post-nav .post-nav-link .nav-label {
            font-size: 0.8rem;
            color: var(--text-light);
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }
        .post-nav .post-nav-link .nav-title {
            font-size: 0.95rem;
            font-weight: 700;
            color: var(--text-dark);
            line-height: 1.4;
        }
        .post-nav .post-nav-link i {
            font-size: 1.4rem;
            color: var(--primary);
        }
        .post-nav .post-nav-link.text-end {
            text-align: right;
        }
        .post-nav .post-nav-link.text-end i {
            order: 1;
        }

        /* ===== Related Posts ===== */
        .related-posts {
            padding: 50px 0;
            background: var(--bg-white);
        }
        .related-posts .section-title {
            font-size: 1.6rem;
            font-weight: 800;
            margin-bottom: 30px;
            color: var(--text-dark);
            letter-spacing: -0.3px;
        }
        .related-posts .related-card {
            background: var(--bg-light);
            border-radius: var(--radius-md);
            padding: 22px 24px;
            transition: var(--transition);
            height: 100%;
            border: 1px solid transparent;
        }
        .related-posts .related-card:hover {
            border-color: var(--border-color);
            box-shadow: var(--shadow-md);
            transform: translateY(-3px);
            background: var(--bg-white);
        }
        .related-posts .related-card .related-cat {
            font-size: 0.75rem;
            font-weight: 700;
            color: var(--primary);
            background: rgba(108, 60, 248, 0.08);
            padding: 2px 12px;
            border-radius: 50px;
            display: inline-block;
            margin-bottom: 8px;
        }
        .related-posts .related-card .related-title {
            font-size: 1.05rem;
            font-weight: 700;
            color: var(--text-dark);
            line-height: 1.4;
            margin-bottom: 8px;
            transition: var(--transition);
        }
        .related-posts .related-card:hover .related-title {
            color: var(--primary);
        }
        .related-posts .related-card .related-date {
            font-size: 0.8rem;
            color: var(--text-light);
        }

        /* ===== CTA Section ===== */
        .cta-section {
            padding: 60px 0;
            background: linear-gradient(135deg, var(--primary) 0%, #4A2DFF 100%);
            color: #fff;
            text-align: center;
        }
        .cta-section h2 {
            font-size: 2rem;
            font-weight: 800;
            letter-spacing: -0.5px;
            margin-bottom: 16px;
        }
        .cta-section p {
            font-size: 1.1rem;
            opacity: 0.9;
            max-width: 600px;
            margin: 0 auto 28px;
        }
        .cta-section .cta-btn {
            background: var(--secondary);
            color: #fff;
            border: none;
            border-radius: 50px;
            padding: 14px 40px;
            font-weight: 700;
            font-size: 1.05rem;
            transition: var(--transition);
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.20);
            display: inline-flex;
            align-items: center;
            gap: 10px;
        }
        .cta-section .cta-btn:hover {
            background: #E55A2B;
            transform: translateY(-3px);
            box-shadow: 0 12px 36px rgba(0, 0, 0, 0.30);
            color: #fff;
        }

        /* ===== FAQ Section ===== */
        .faq-section {
            padding: 50px 0;
            background: var(--bg-light);
        }
        .faq-section .section-title {
            font-size: 1.6rem;
            font-weight: 800;
            margin-bottom: 30px;
            color: var(--text-dark);
            letter-spacing: -0.3px;
            text-align: center;
        }
        .faq-section .accordion-item {
            border: none;
            border-radius: var(--radius-md);
            margin-bottom: 12px;
            background: var(--bg-white);
            box-shadow: var(--shadow-sm);
            overflow: hidden;
        }
        .faq-section .accordion-button {
            font-weight: 700;
            font-size: 1rem;
            color: var(--text-dark);
            background: var(--bg-white);
            padding: 18px 24px;
            border: none;
            box-shadow: none;
            transition: var(--transition);
        }
        .faq-section .accordion-button:not(.collapsed) {
            color: var(--primary);
            background: rgba(108, 60, 248, 0.04);
        }
        .faq-section .accordion-button::after {
            background-size: 16px;
            transition: var(--transition);
        }
        .faq-section .accordion-button:focus {
            box-shadow: none;
            border-color: var(--primary-light);
        }
        .faq-section .accordion-body {
            padding: 4px 24px 20px;
            color: var(--text-muted);
            font-size: 0.95rem;
            line-height: 1.7;
        }

        /* ===== Error State ===== */
        .error-state {
            text-align: center;
            padding: 60px 20px;
        }
        .error-state i {
            font-size: 3.5rem;
            color: var(--text-light);
            margin-bottom: 20px;
        }
        .error-state h2 {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--text-dark);
            margin-bottom: 12px;
        }
        .error-state p {
            color: var(--text-muted);
            font-size: 1.05rem;
            margin-bottom: 24px;
        }
        .error-state .btn-back {
            background: var(--primary);
            color: #fff;
            border: none;
            border-radius: 50px;
            padding: 12px 32px;
            font-weight: 700;
            transition: var(--transition);
        }
        .error-state .btn-back:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
            color: #fff;
        }

        /* ===== Footer ===== */
        .site-footer {
            background: var(--bg-dark);
            color: rgba(255, 255, 255, 0.75);
            padding: 50px 0 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.06);
        }
        .site-footer .footer-logo {
            font-size: 1.4rem;
            font-weight: 800;
            color: #fff;
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 12px;
        }
        .site-footer .footer-logo i {
            color: var(--primary-light);
        }
        .site-footer .footer-desc {
            font-size: 0.9rem;
            line-height: 1.7;
            color: rgba(255, 255, 255, 0.55);
            max-width: 320px;
        }
        .site-footer h5 {
            color: #fff;
            font-weight: 700;
            font-size: 1rem;
            margin-bottom: 16px;
            letter-spacing: 0.3px;
        }
        .site-footer .footer-links {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        .site-footer .footer-links li {
            margin-bottom: 10px;
        }
        .site-footer .footer-links a {
            color: rgba(255, 255, 255, 0.55);
            font-size: 0.9rem;
            transition: var(--transition);
        }
        .site-footer .footer-links a:hover {
            color: var(--primary-light);
            padding-left: 4px;
        }
        .site-footer .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.06);
            padding-top: 22px;
            margin-top: 30px;
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.35);
            text-align: center;
        }
        .site-footer .footer-bottom a {
            color: rgba(255, 255, 255, 0.45);
        }
        .site-footer .footer-bottom a:hover {
            color: var(--primary-light);
        }

        /* ===== Responsive ===== */
        @media (max-width: 991px) {
            .site-header .navbar-nav .nav-link.active::after {
                display: none;
            }
            .site-header .navbar-nav .nav-link {
                padding: 10px 16px;
                border-radius: var(--radius-sm);
            }
            .search-box {
                margin-top: 8px;
                width: 100%;
            }
            .search-box input {
                width: 100%;
            }
            .nav-cta {
                margin-top: 8px;
                width: 100%;
                justify-content: center;
            }
            .article-hero h1 {
                font-size: 1.7rem;
            }
            .article-content .content-body {
                font-size: 0.98rem;
            }
            .cta-section h2 {
                font-size: 1.5rem;
            }
            .related-posts .related-card {
                margin-bottom: 16px;
            }
        }

        @media (max-width: 767px) {
            .article-hero {
                padding: 28px 0 20px;
            }
            .article-hero h1 {
                font-size: 1.4rem;
            }
            .article-hero .meta-info {
                gap: 12px;
                font-size: 0.82rem;
                flex-wrap: wrap;
            }
            .article-content-wrap {
                padding: 24px 0 30px;
            }
            .article-content .content-body {
                font-size: 0.95rem;
                line-height: 1.75;
            }
            .article-content .content-body h2 {
                font-size: 1.3rem;
            }
            .article-content .content-body h3 {
                font-size: 1.1rem;
            }
            .post-nav .post-nav-link {
                margin-bottom: 12px;
                padding: 14px 18px;
            }
            .related-posts .section-title {
                font-size: 1.3rem;
            }
            .cta-section {
                padding: 40px 0;
            }
            .cta-section h2 {
                font-size: 1.3rem;
            }
            .cta-section p {
                font-size: 0.95rem;
            }
            .faq-section .section-title {
                font-size: 1.3rem;
            }
            .site-footer .footer-logo {
                font-size: 1.2rem;
            }
            .site-footer .footer-desc {
                max-width: 100%;
            }
            .site-footer h5 {
                margin-top: 16px;
            }
            .error-state i {
                font-size: 2.5rem;
            }
            .error-state h2 {
                font-size: 1.4rem;
            }
        }

        @media (max-width: 520px) {
            .article-hero h1 {
                font-size: 1.2rem;
            }
            .article-hero .category-badge {
                font-size: 0.7rem;
                padding: 3px 12px;
            }
            .article-content .content-body {
                font-size: 0.9rem;
            }
            .article-content .tag-list .tag {
                font-size: 0.75rem;
                padding: 4px 12px;
            }
            .cta-section .cta-btn {
                padding: 12px 28px;
                font-size: 0.95rem;
            }
            .faq-section .accordion-button {
                font-size: 0.9rem;
                padding: 14px 18px;
            }
            .faq-section .accordion-body {
                font-size: 0.88rem;
                padding: 2px 18px 16px;
            }
            .site-footer {
                padding: 30px 0 20px;
            }
            .related-posts .related-card .related-title {
                font-size: 0.95rem;
            }
        }

/* roulang page: category1 */
/* ===== 设计变量 ===== */
        :root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --primary-light: #3b82f6;
            --primary-bg: #eff6ff;
            --secondary: #f59e0b;
            --secondary-dark: #d97706;
            --accent: #8b5cf6;
            --success: #10b981;
            --danger: #ef4444;
            --gray-50: #f8fafc;
            --gray-100: #f1f5f9;
            --gray-200: #e2e8f0;
            --gray-300: #cbd5e1;
            --gray-400: #94a3b8;
            --gray-500: #64748b;
            --gray-600: #475569;
            --gray-700: #334155;
            --gray-800: #1e293b;
            --gray-900: #0f172a;
            --white: #ffffff;
            --body-bg: #f8fafc;
            --body-text: #1e293b;
            --text-muted: #64748b;
            --border-radius: 12px;
            --border-radius-sm: 8px;
            --border-radius-lg: 16px;
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
            --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
            --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
            --shadow-xl: 0 20px 48px rgba(0,0,0,0.16);
            --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
            --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            --container-max: 1200px;
            --header-height: 72px;
        }
        /* ===== Reset & Base ===== */
        *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
        body {
            font-family: var(--font-sans);
            font-size: 16px;
            line-height: 1.7;
            color: var(--body-text);
            background: var(--body-bg);
            padding-top: var(--header-height);
        }
        a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
        a:hover { color: var(--primary-dark); }
        img { max-width: 100%; height: auto; display: block; }
        button, input, textarea, select { font-family: inherit; font-size: inherit; }
        ul, ol { list-style: none; }
        h1, h2, h3, h4, h5, h6 { line-height: 1.3; font-weight: 700; color: var(--gray-900); }
        p { margin-bottom: 0; }
        /* ===== 容器 ===== */
        .container { max-width: var(--container-max); padding-left: 20px; padding-right: 20px; margin: 0 auto; width: 100%; }
        /* ===== Header / Nav ===== */
        .site-header {
            position: fixed; top: 0; left: 0; right: 0; z-index: 1050;
            background: rgba(255,255,255,0.95);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--gray-200);
            height: var(--header-height);
            display: flex; align-items: center;
            transition: box-shadow var(--transition);
        }
        .site-header.scrolled { box-shadow: var(--shadow-md); }
        .site-header .container { display: flex; align-items: center; justify-content: space-between; }
        .navbar { padding: 0; width: 100%; display: flex; align-items: center; justify-content: space-between; }
        .navbar-brand {
            font-size: 1.4rem; font-weight: 800; color: var(--gray-900);
            display: flex; align-items: center; gap: 10px;
            letter-spacing: -0.02em;
            transition: color var(--transition);
        }
        .navbar-brand i { color: var(--primary); font-size: 1.5rem; }
        .navbar-brand:hover { color: var(--primary); }
        .navbar-nav { gap: 4px; }
        .nav-link {
            padding: 8px 16px !important;
            font-weight: 500; font-size: 0.95rem;
            color: var(--gray-600) !important;
            border-radius: var(--border-radius-sm);
            transition: all var(--transition);
            position: relative;
        }
        .nav-link:hover { color: var(--primary) !important; background: var(--primary-bg); }
        .nav-link.active {
            color: var(--primary) !important;
            background: var(--primary-bg);
            font-weight: 600;
        }
        .nav-link.active::after {
            content: ''; position: absolute; bottom: 2px; left: 16px; right: 16px;
            height: 3px; background: var(--primary); border-radius: 3px;
        }
        .search-box {
            display: flex; align-items: center;
            background: var(--gray-100); border-radius: 50px;
            padding: 2px 2px 2px 16px;
            border: 1px solid transparent;
            transition: all var(--transition);
            max-width: 200px;
        }
        .search-box:focus-within { border-color: var(--primary); background: var(--white); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
        .search-box input {
            border: none; background: transparent; padding: 6px 0;
            font-size: 0.9rem; color: var(--gray-800); outline: none; width: 120px;
        }
        .search-box input::placeholder { color: var(--gray-400); }
        .search-box button {
            background: var(--primary); border: none; color: var(--white);
            width: 32px; height: 32px; border-radius: 50%;
            display: flex; align-items: center; justify-content: center;
            cursor: pointer; transition: background var(--transition);
        }
        .search-box button:hover { background: var(--primary-dark); }
        .nav-cta {
            border-radius: 50px !important;
            padding: 8px 20px !important; font-weight: 600 !important;
            font-size: 0.9rem !important;
            display: flex; align-items: center; gap: 8px;
            background: var(--primary) !important; border-color: var(--primary) !important;
            transition: all var(--transition) !important;
            white-space: nowrap;
        }
        .nav-cta:hover { background: var(--primary-dark) !important; border-color: var(--primary-dark) !important; transform: translateY(-1px); box-shadow: var(--shadow-md); }
        .navbar-toggler { border: none; color: var(--gray-700); font-size: 1.4rem; padding: 4px 8px; background: transparent; }
        .navbar-toggler:focus { box-shadow: none; }
        /* ===== Hero 分类标题区 ===== */
        .category-hero {
            background: linear-gradient(135deg, #1e293b 0%, #334155 60%, #0f172a 100%);
            padding: 80px 0 64px;
            position: relative;
            overflow: hidden;
        }
        .category-hero::before {
            content: ''; position: absolute; inset: 0;
            background: radial-gradient(circle at 20% 50%, rgba(37,99,235,0.15) 0%, transparent 60%),
                        radial-gradient(circle at 80% 30%, rgba(139,92,246,0.1) 0%, transparent 50%);
            pointer-events: none;
        }
        .category-hero .container { position: relative; z-index: 1; }
        .category-hero h1 {
            font-size: 2.6rem; font-weight: 800; color: var(--white);
            margin-bottom: 12px; letter-spacing: -0.02em;
        }
        .category-hero h1 i { color: var(--secondary); margin-right: 12px; }
        .category-hero .lead {
            font-size: 1.15rem; color: rgba(255,255,255,0.75);
            max-width: 680px; line-height: 1.7;
        }
        .breadcrumb-custom {
            display: flex; align-items: center; gap: 8px;
            padding: 0; margin-bottom: 20px; font-size: 0.9rem;
            color: rgba(255,255,255,0.5);
        }
        .breadcrumb-custom a { color: rgba(255,255,255,0.65); transition: color var(--transition); }
        .breadcrumb-custom a:hover { color: var(--white); }
        .breadcrumb-custom span { color: rgba(255,255,255,0.85); }
        .breadcrumb-custom .sep { color: rgba(255,255,255,0.3); }
        .category-hero .hero-badges {
            display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px;
        }
        .category-hero .hero-badges .badge {
            background: rgba(255,255,255,0.12); color: rgba(255,255,255,0.85);
            padding: 6px 16px; border-radius: 50px;
            font-weight: 500; font-size: 0.85rem;
            backdrop-filter: blur(4px);
            border: 1px solid rgba(255,255,255,0.08);
        }
        /* ===== 平台简介区 ===== */
        .section-intro {
            padding: 72px 0 56px; background: var(--white);
        }
        .section-intro .intro-grid {
            display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center;
        }
        .section-intro .intro-text h2 {
            font-size: 2rem; font-weight: 700; margin-bottom: 16px;
            color: var(--gray-900);
        }
        .section-intro .intro-text p {
            color: var(--gray-600); font-size: 1.05rem; line-height: 1.8;
        }
        .section-intro .intro-stats {
            display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
        }
        .stat-card {
            background: var(--gray-50); border-radius: var(--border-radius);
            padding: 24px 20px; text-align: center;
            border: 1px solid var(--gray-100);
            transition: all var(--transition);
        }
        .stat-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--gray-200); }
        .stat-card .stat-number {
            font-size: 2rem; font-weight: 800; color: var(--primary);
            line-height: 1.2;
        }
        .stat-card .stat-label {
            font-size: 0.9rem; color: var(--gray-500); margin-top: 4px;
        }
        /* ===== 指南标签 ===== */
        .section-tags {
            padding: 48px 0; background: var(--gray-50);
        }
        .section-tags .tag-list {
            display: flex; flex-wrap: wrap; gap: 12px; justify-content: center;
        }
        .section-tags .tag-item {
            padding: 8px 22px; border-radius: 50px;
            background: var(--white); color: var(--gray-700);
            font-weight: 500; font-size: 0.9rem;
            border: 1px solid var(--gray-200);
            transition: all var(--transition);
            cursor: default;
        }
        .section-tags .tag-item:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-bg); }
        .section-tags .tag-item.tag-active { background: var(--primary); color: var(--white); border-color: var(--primary); }
        /* ===== 指南文章列表 ===== */
        .section-guides {
            padding: 72px 0; background: var(--white);
        }
        .section-guides .section-title {
            text-align: center; margin-bottom: 48px;
        }
        .section-guides .section-title h2 {
            font-size: 2rem; font-weight: 700;
        }
        .section-guides .section-title p {
            color: var(--gray-500); margin-top: 8px; font-size: 1.05rem;
        }
        .guide-card {
            background: var(--white);
            border: 1px solid var(--gray-100);
            border-radius: var(--border-radius);
            padding: 32px 28px;
            transition: all var(--transition);
            height: 100%;
            display: flex; flex-direction: column;
        }
        .guide-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--gray-200); }
        .guide-card .guide-icon {
            width: 52px; height: 52px; border-radius: 14px;
            display: flex; align-items: center; justify-content: center;
            font-size: 1.4rem; margin-bottom: 18px;
            background: var(--primary-bg); color: var(--primary);
        }
        .guide-card .guide-icon.icon2 { background: #fef3c7; color: #d97706; }
        .guide-card .guide-icon.icon3 { background: #ede9fe; color: #7c3aed; }
        .guide-card .guide-icon.icon4 { background: #d1fae5; color: #059669; }
        .guide-card .guide-icon.icon5 { background: #fce4ec; color: #e11d48; }
        .guide-card .guide-icon.icon6 { background: #e0f2fe; color: #0284c7; }
        .guide-card h3 {
            font-size: 1.2rem; font-weight: 700; margin-bottom: 10px;
            color: var(--gray-900);
        }
        .guide-card p {
            color: var(--gray-500); font-size: 0.95rem; line-height: 1.7;
            flex: 1;
        }
        .guide-card .guide-meta {
            display: flex; align-items: center; gap: 16px;
            margin-top: 18px; padding-top: 16px;
            border-top: 1px solid var(--gray-100);
            font-size: 0.85rem; color: var(--gray-400);
        }
        .guide-card .guide-meta i { margin-right: 4px; }
        .guide-card .guide-link {
            display: inline-flex; align-items: center; gap: 6px;
            font-weight: 600; font-size: 0.9rem; color: var(--primary);
            margin-top: 14px; transition: gap var(--transition);
        }
        .guide-card .guide-link:hover { gap: 10px; color: var(--primary-dark); }
        /* ===== 使用流程 ===== */
        .section-process {
            padding: 72px 0; background: var(--gray-50);
        }
        .section-process .section-title {
            text-align: center; margin-bottom: 48px;
        }
        .section-process .section-title h2 { font-size: 2rem; font-weight: 700; }
        .section-process .section-title p { color: var(--gray-500); margin-top: 8px; }
        .process-steps {
            display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
            position: relative;
        }
        .process-steps::before {
            content: ''; position: absolute; top: 40px; left: 15%; right: 15%;
            height: 3px; background: linear-gradient(to right, var(--primary), var(--accent));
            border-radius: 3px;
        }
        .process-step {
            text-align: center; position: relative; z-index: 1;
        }
        .process-step .step-num {
            width: 52px; height: 52px; border-radius: 50%;
            background: var(--white); border: 3px solid var(--primary);
            display: flex; align-items: center; justify-content: center;
            font-size: 1.3rem; font-weight: 800; color: var(--primary);
            margin: 0 auto 16px;
            transition: all var(--transition);
        }
        .process-step:hover .step-num { background: var(--primary); color: var(--white); box-shadow: 0 0 0 8px rgba(37,99,235,0.12); }
        .process-step h4 { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; }
        .process-step p { font-size: 0.9rem; color: var(--gray-500); }
        /* ===== FAQ ===== */
        .section-faq {
            padding: 72px 0; background: var(--white);
        }
        .section-faq .section-title {
            text-align: center; margin-bottom: 48px;
        }
        .section-faq .section-title h2 { font-size: 2rem; font-weight: 700; }
        .section-faq .section-title p { color: var(--gray-500); margin-top: 8px; }
        .faq-item {
            border: 1px solid var(--gray-100); border-radius: var(--border-radius-sm);
            margin-bottom: 12px; overflow: hidden;
            transition: all var(--transition);
        }
        .faq-item:hover { border-color: var(--gray-200); box-shadow: var(--shadow-sm); }
        .faq-question {
            padding: 18px 24px; background: var(--gray-50);
            font-weight: 600; font-size: 1rem; color: var(--gray-800);
            cursor: pointer; display: flex; align-items: center; justify-content: space-between;
            transition: background var(--transition);
            border: none; width: 100%; text-align: left;
        }
        .faq-question:hover { background: var(--gray-100); }
        .faq-question i { color: var(--primary); transition: transform var(--transition); font-size: 0.9rem; }
        .faq-question[aria-expanded="true"] i { transform: rotate(180deg); }
        .faq-answer {
            padding: 0 24px 18px; color: var(--gray-600); font-size: 0.95rem; line-height: 1.7;
        }
        /* ===== CTA ===== */
        .section-cta {
            padding: 72px 0; background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
            text-align: center; position: relative; overflow: hidden;
        }
        .section-cta::before {
            content: ''; position: absolute; inset: 0;
            background: radial-gradient(circle at 70% 50%, rgba(37,99,235,0.12) 0%, transparent 60%);
            pointer-events: none;
        }
        .section-cta .container { position: relative; z-index: 1; }
        .section-cta h2 {
            font-size: 2.2rem; font-weight: 800; color: var(--white);
            margin-bottom: 12px;
        }
        .section-cta p {
            color: rgba(255,255,255,0.65); font-size: 1.1rem;
            max-width: 560px; margin: 0 auto 28px;
        }
        .section-cta .btn-cta {
            background: var(--secondary); border: none; color: var(--gray-900);
            padding: 14px 40px; border-radius: 50px; font-weight: 700; font-size: 1.05rem;
            display: inline-flex; align-items: center; gap: 10px;
            transition: all var(--transition);
        }
        .section-cta .btn-cta:hover { background: var(--secondary-dark); transform: translateY(-3px); box-shadow: var(--shadow-xl); }
        /* ===== Footer ===== */
        .site-footer {
            background: #0f172a; color: rgba(255,255,255,0.65);
            padding: 56px 0 32px;
        }
        .site-footer .footer-logo {
            font-size: 1.4rem; font-weight: 800; color: var(--white);
            display: flex; align-items: center; gap: 10px; margin-bottom: 12px;
        }
        .site-footer .footer-logo i { color: var(--primary); }
        .site-footer .footer-desc {
            font-size: 0.9rem; line-height: 1.7; color: rgba(255,255,255,0.5);
            max-width: 360px;
        }
        .site-footer h5 {
            color: var(--white); font-weight: 700; font-size: 1rem;
            margin-bottom: 16px;
        }
        .site-footer .footer-links li { margin-bottom: 8px; }
        .site-footer .footer-links a {
            color: rgba(255,255,255,0.55); font-size: 0.9rem;
            transition: color var(--transition);
        }
        .site-footer .footer-links a:hover { color: var(--primary-light); }
        .site-footer .footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.08);
            padding-top: 24px; margin-top: 40px;
            font-size: 0.85rem; color: rgba(255,255,255,0.35);
            display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
        }
        .site-footer .footer-bottom a { color: rgba(255,255,255,0.35); }
        .site-footer .footer-bottom a:hover { color: var(--primary-light); }
        /* ===== 响应式 ===== */
        @media (max-width: 1024px) {
            .process-steps { grid-template-columns: repeat(2, 1fr); }
            .process-steps::before { display: none; }
            .section-intro .intro-grid { grid-template-columns: 1fr; gap: 32px; }
        }
        @media (max-width: 768px) {
            :root { --header-height: 64px; }
            .category-hero { padding: 56px 0 48px; }
            .category-hero h1 { font-size: 1.8rem; }
            .category-hero .lead { font-size: 1rem; }
            .section-intro .intro-stats { grid-template-columns: 1fr 1fr; gap: 12px; }
            .stat-card .stat-number { font-size: 1.5rem; }
            .section-guides .guide-card { padding: 24px 20px; }
            .process-steps { grid-template-columns: 1fr 1fr; gap: 16px; }
            .process-step .step-num { width: 44px; height: 44px; font-size: 1.1rem; }
            .section-cta h2 { font-size: 1.6rem; }
            .site-footer .row > div { margin-bottom: 24px; }
            .search-box { max-width: 140px; }
            .search-box input { width: 80px; }
        }
        @media (max-width: 520px) {
            body { padding-top: 60px; }
            .category-hero h1 { font-size: 1.4rem; }
            .category-hero .hero-badges .badge { font-size: 0.75rem; padding: 4px 12px; }
            .section-intro { padding: 48px 0 32px; }
            .section-intro .intro-stats { grid-template-columns: 1fr 1fr; gap: 10px; }
            .stat-card { padding: 16px 12px; }
            .stat-card .stat-number { font-size: 1.3rem; }
            .section-guides { padding: 48px 0; }
            .section-guides .section-title h2 { font-size: 1.5rem; }
            .section-process { padding: 48px 0; }
            .section-process .section-title h2 { font-size: 1.5rem; }
            .process-steps { grid-template-columns: 1fr; gap: 20px; }
            .section-faq { padding: 48px 0; }
            .section-faq .section-title h2 { font-size: 1.5rem; }
            .faq-question { padding: 14px 16px; font-size: 0.9rem; }
            .faq-answer { padding: 0 16px 14px; font-size: 0.85rem; }
            .section-cta { padding: 48px 0; }
            .section-cta h2 { font-size: 1.3rem; }
            .section-cta .btn-cta { padding: 12px 28px; font-size: 0.95rem; }
            .site-footer { padding: 40px 0 24px; }
            .site-footer .footer-logo { font-size: 1.2rem; }
            .navbar-brand { font-size: 1.15rem; }
            .navbar-brand i { font-size: 1.2rem; }
            .nav-link { padding: 6px 12px !important; font-size: 0.85rem; }
            .search-box { max-width: 100px; }
            .search-box input { width: 50px; }
            .nav-cta { padding: 6px 14px !important; font-size: 0.8rem !important; }
        }
        /* ===== 工具类 ===== */
        .text-primary { color: var(--primary) !important; }
        .bg-primary-light { background: var(--primary-bg); }
        .section-padding { padding: 72px 0; }
        @media (max-width: 768px) { .section-padding { padding: 48px 0; } }