/* roulang page: index */
:root {
            --brand-primary: #1f7a6e;
            --brand-primary-light: #4ab0a1;
            --brand-primary-dark: #19423d;
            --accent-blue: #3366ff;
            --bg-body: #f8fafb;
            --bg-card: #ffffff;
            --text-primary: #1a1d23;
            --text-secondary: #4b5563;
            --text-muted: #9ca3af;
            --border-light: #e5e9f0;
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 20px;
            --radius-xl: 28px;
            --transition-base: 0.2s ease;
            --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        html {
            scroll-behavior: smooth;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        body {
            margin: 0;
            padding: 0;
            font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
            background-color: var(--bg-body);
            color: var(--text-primary);
            line-height: 1.6;
        }

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

        a {
            color: inherit;
            text-decoration: none;
            transition: color var(--transition-base);
        }

        button {
            cursor: pointer;
            font-family: inherit;
        }

        input,
        textarea {
            font-family: inherit;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        @media (max-width: 640px) {
            .container {
                padding: 0 16px;
            }
        }

        /* header & nav */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 50;
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid rgba(229, 233, 240, 0.6);
            transition: box-shadow var(--transition-smooth);
        }

        .site-header.scrolled {
            box-shadow: 0 1px 8px rgba(0, 0, 0, 0.06);
        }

        .nav-container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 68px;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.35rem;
            font-weight: 700;
            color: var(--brand-primary-dark);
            letter-spacing: -0.3px;
        }

        .nav-logo .logo-icon {
            width: 36px;
            height: 36px;
            background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-light));
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 1.1rem;
            font-weight: 800;
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 8px;
            list-style: none;
            margin: 0;
            padding: 0;
        }

        .nav-links a {
            padding: 8px 18px;
            border-radius: 8px;
            font-size: 0.95rem;
            font-weight: 500;
            color: var(--text-secondary);
            transition: all var(--transition-base);
            position: relative;
        }

        .nav-links a:hover {
            color: var(--brand-primary);
            background: rgba(31, 122, 110, 0.06);
        }

        .nav-links a.active {
            color: var(--brand-primary);
            background: rgba(31, 122, 110, 0.10);
            font-weight: 600;
        }

        .nav-right {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .nav-search {
            display: flex;
            align-items: center;
            background: #f1f3f6;
            border-radius: 10px;
            padding: 0 14px;
            height: 40px;
            border: 1px solid transparent;
            transition: all var(--transition-base);
            min-width: 180px;
        }

        .nav-search:focus-within {
            background: #fff;
            border-color: var(--brand-primary-light);
            box-shadow: 0 0 0 3px rgba(31, 122, 110, 0.10);
        }

        .nav-search i {
            color: var(--text-muted);
            font-size: 0.9rem;
            margin-right: 8px;
        }

        .nav-search input {
            background: transparent;
            border: none;
            outline: none;
            font-size: 0.9rem;
            color: var(--text-primary);
            width: 100%;
        }

        .nav-search input::placeholder {
            color: var(--text-muted);
        }

        .nav-cta {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 10px 24px;
            background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-light));
            color: #fff;
            border-radius: 10px;
            font-weight: 600;
            font-size: 0.9rem;
            border: none;
            transition: all var(--transition-smooth);
            box-shadow: 0 2px 10px rgba(31, 122, 110, 0.25);
        }

        .nav-cta:hover {
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(31, 122, 110, 0.35);
        }

        .nav-cta:active {
            transform: translateY(0);
            box-shadow: 0 2px 8px rgba(31, 122, 110, 0.20);
        }

        .nav-mobile-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.4rem;
            color: var(--text-primary);
            padding: 8px;
            border-radius: 8px;
        }

        .nav-mobile-toggle:hover {
            background: rgba(0, 0, 0, 0.04);
        }

        @media (max-width: 900px) {
            .nav-links {
                display: none;
                position: absolute;
                top: 68px;
                left: 0;
                right: 0;
                background: rgba(255, 255, 255, 0.98);
                backdrop-filter: blur(16px);
                flex-direction: column;
                padding: 16px 24px;
                gap: 4px;
                border-bottom: 1px solid var(--border-light);
                box-shadow: 0 12px 32px rgba(0, 0, 0, 0.06);
            }
            .nav-links.open {
                display: flex;
            }
            .nav-links a {
                padding: 12px 16px;
                width: 100%;
                border-radius: 8px;
            }
            .nav-search {
                min-width: unset;
                width: 140px;
            }
            .nav-mobile-toggle {
                display: block;
            }
            .nav-cta span {
                display: none;
            }
        }

        @media (max-width: 520px) {
            .nav-container {
                padding: 0 12px;
                height: 60px;
            }
            .nav-logo {
                font-size: 1.1rem;
            }
            .nav-logo .logo-icon {
                width: 30px;
                height: 30px;
                font-size: 0.9rem;
            }
            .nav-search {
                width: 100px;
                padding: 0 10px;
            }
            .nav-cta {
                padding: 8px 14px;
                font-size: 0.8rem;
            }
        }

        /* hero */
        .hero {
            position: relative;
            min-height: 88vh;
            display: flex;
            align-items: center;
            padding-top: 68px;
            background: linear-gradient(135deg, #0a2724 0%, #1a5049 40%, #1f7a6e 100%);
            overflow: hidden;
        }

        .hero-bg {
            position: absolute;
            inset: 0;
            background-image: url('/assets/images/backpic/back-1.png');
            background-size: cover;
            background-position: center;
            opacity: 0.20;
            mix-blend-mode: overlay;
        }

        .hero-overlay {
            position: absolute;
            inset: 0;
            background: radial-gradient(ellipse at 30% 50%, rgba(31, 122, 110, 0.25) 0%, transparent 70%),
                radial-gradient(ellipse at 70% 30%, rgba(51, 102, 255, 0.10) 0%, transparent 50%);
        }

        .hero-content {
            position: relative;
            z-index: 2;
            width: 100%;
            padding: 80px 24px 100px;
        }

        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: rgba(255, 255, 255, 0.10);
            backdrop-filter: blur(4px);
            border: 1px solid rgba(255, 255, 255, 0.12);
            padding: 6px 18px;
            border-radius: 50px;
            color: rgba(255, 255, 255, 0.85);
            font-size: 0.85rem;
            font-weight: 500;
            margin-bottom: 28px;
        }

        .hero-badge i {
            font-size: 0.7rem;
            color: var(--brand-primary-light);
        }

        .hero h1 {
            font-size: 3.8rem;
            font-weight: 800;
            line-height: 1.15;
            color: #fff;
            letter-spacing: -0.5px;
            max-width: 780px;
            margin-bottom: 24px;
        }

        .hero h1 .highlight {
            background: linear-gradient(135deg, #75c9bd, #a9ddd5);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .hero p {
            font-size: 1.2rem;
            color: rgba(255, 255, 255, 0.75);
            max-width: 600px;
            line-height: 1.7;
            margin-bottom: 36px;
        }

        .hero-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            align-items: center;
        }

        .hero-actions .btn-primary {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            padding: 14px 34px;
            background: #fff;
            color: var(--brand-primary-dark);
            border-radius: 12px;
            font-weight: 700;
            font-size: 1.05rem;
            border: none;
            transition: all var(--transition-smooth);
            box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
        }

        .hero-actions .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 32px rgba(0, 0, 0, 0.20);
        }

        .hero-actions .btn-secondary {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 28px;
            background: rgba(255, 255, 255, 0.08);
            color: rgba(255, 255, 255, 0.9);
            border-radius: 12px;
            font-weight: 600;
            font-size: 1rem;
            border: 1px solid rgba(255, 255, 255, 0.15);
            transition: all var(--transition-smooth);
        }

        .hero-actions .btn-secondary:hover {
            background: rgba(255, 255, 255, 0.15);
            border-color: rgba(255, 255, 255, 0.25);
        }

        .hero-stats {
            display: flex;
            flex-wrap: wrap;
            gap: 32px 48px;
            margin-top: 56px;
            padding-top: 40px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
        }

        .hero-stat {
            color: #fff;
        }

        .hero-stat .num {
            font-size: 2.2rem;
            font-weight: 800;
            letter-spacing: -0.5px;
            color: #fff;
        }

        .hero-stat .num span {
            color: var(--brand-primary-light);
        }

        .hero-stat .label {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.55);
            margin-top: 4px;
        }

        @media (max-width: 768px) {
            .hero {
                min-height: auto;
                padding-top: 60px;
            }
            .hero-content {
                padding: 60px 16px 70px;
            }
            .hero h1 {
                font-size: 2.4rem;
            }
            .hero p {
                font-size: 1rem;
            }
            .hero-actions .btn-primary,
            .hero-actions .btn-secondary {
                padding: 12px 24px;
                font-size: 0.95rem;
            }
            .hero-stats {
                gap: 20px 32px;
                margin-top: 40px;
                padding-top: 28px;
            }
            .hero-stat .num {
                font-size: 1.6rem;
            }
        }

        @media (max-width: 520px) {
            .hero h1 {
                font-size: 1.8rem;
            }
            .hero-actions {
                flex-direction: column;
                align-items: stretch;
            }
            .hero-actions .btn-primary,
            .hero-actions .btn-secondary {
                justify-content: center;
            }
            .hero-stats {
                flex-direction: column;
                gap: 16px;
            }
        }

        /* sections */
        .section {
            padding: 80px 0;
        }

        .section-header {
            text-align: center;
            margin-bottom: 56px;
        }

        .section-header h2 {
            font-size: 2.2rem;
            font-weight: 800;
            color: var(--text-primary);
            letter-spacing: -0.3px;
            margin-bottom: 12px;
        }

        .section-header p {
            font-size: 1.1rem;
            color: var(--text-secondary);
            max-width: 560px;
            margin: 0 auto;
        }

        .section-header .badge-label {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            background: rgba(31, 122, 110, 0.08);
            color: var(--brand-primary);
            padding: 4px 14px;
            border-radius: 50px;
            font-size: 0.8rem;
            font-weight: 600;
            margin-bottom: 16px;
            letter-spacing: 0.3px;
        }

        @media (max-width: 640px) {
            .section {
                padding: 56px 0;
            }
            .section-header {
                margin-bottom: 36px;
            }
            .section-header h2 {
                font-size: 1.6rem;
            }
            .section-header p {
                font-size: 0.95rem;
            }
        }

        /* features grid */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
        }

        .feature-card {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            padding: 32px 24px;
            border: 1px solid var(--border-light);
            box-shadow: var(--shadow-card, 0 2px 12px rgba(0, 0, 0, 0.03));
            transition: all var(--transition-smooth);
        }

        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover, 0 12px 40px rgba(0, 0, 0, 0.07));
            border-color: rgba(31, 122, 110, 0.15);
        }

        .feature-icon {
            width: 52px;
            height: 52px;
            border-radius: 14px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.4rem;
            margin-bottom: 20px;
            background: rgba(31, 122, 110, 0.08);
            color: var(--brand-primary);
        }

        .feature-card h3 {
            font-size: 1.15rem;
            font-weight: 700;
            margin-bottom: 10px;
            color: var(--text-primary);
        }

        .feature-card p {
            font-size: 0.92rem;
            color: var(--text-secondary);
            line-height: 1.65;
            margin: 0;
        }

        @media (max-width: 1024px) {
            .features-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 520px) {
            .features-grid {
                grid-template-columns: 1fr;
            }
            .feature-card {
                padding: 24px 20px;
            }
        }

        /* categories */
        .categories-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }

        .category-card {
            position: relative;
            border-radius: var(--radius-md);
            overflow: hidden;
            background: var(--bg-card);
            border: 1px solid var(--border-light);
            box-shadow: var(--shadow-card, 0 2px 12px rgba(0, 0, 0, 0.03));
            transition: all var(--transition-smooth);
            display: block;
        }

        .category-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover, 0 12px 40px rgba(0, 0, 0, 0.08));
            border-color: rgba(31, 122, 110, 0.12);
        }

        .category-card .card-img {
            width: 100%;
            height: 180px;
            object-fit: cover;
            background: #e5e9f0;
        }

        .category-card .card-body {
            padding: 20px 22px 24px;
        }

        .category-card .card-body h3 {
            font-size: 1.1rem;
            font-weight: 700;
            margin-bottom: 6px;
            color: var(--text-primary);
        }

        .category-card .card-body p {
            font-size: 0.88rem;
            color: var(--text-secondary);
            margin: 0 0 14px 0;
            line-height: 1.5;
        }

        .category-card .card-tag {
            display: inline-flex;
            align-items: center;
            gap: 4px;
            font-size: 0.78rem;
            color: var(--brand-primary);
            font-weight: 600;
            background: rgba(31, 122, 110, 0.06);
            padding: 2px 12px;
            border-radius: 50px;
        }

        @media (max-width: 1024px) {
            .categories-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 520px) {
            .categories-grid {
                grid-template-columns: 1fr;
            }
            .category-card .card-img {
                height: 140px;
            }
        }

        /* posts list */
        .posts-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }

        .post-card {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            overflow: hidden;
            border: 1px solid var(--border-light);
            box-shadow: var(--shadow-card, 0 2px 12px rgba(0, 0, 0, 0.03));
            transition: all var(--transition-smooth);
            display: flex;
            flex-direction: column;
        }

        .post-card:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-card-hover, 0 12px 40px rgba(0, 0, 0, 0.07));
            border-color: rgba(31, 122, 110, 0.10);
        }

        .post-card .post-img {
            width: 100%;
            height: 180px;
            object-fit: cover;
            background: #e5e9f0;
            flex-shrink: 0;
        }

        .post-card .post-body {
            padding: 20px 22px 24px;
            flex: 1;
            display: flex;
            flex-direction: column;
        }

        .post-card .post-meta {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 10px;
            font-size: 0.78rem;
            color: var(--text-muted);
        }

        .post-card .post-meta .cat {
            background: rgba(31, 122, 110, 0.08);
            color: var(--brand-primary);
            padding: 2px 10px;
            border-radius: 50px;
            font-weight: 600;
        }

        .post-card .post-body h3 {
            font-size: 1.05rem;
            font-weight: 700;
            margin-bottom: 8px;
            color: var(--text-primary);
            line-height: 1.4;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .post-card .post-body p {
            font-size: 0.88rem;
            color: var(--text-secondary);
            line-height: 1.6;
            margin: 0 0 14px 0;
            flex: 1;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .post-card .post-link {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--brand-primary);
            transition: gap var(--transition-base);
        }

        .post-card .post-link:hover {
            gap: 10px;
        }

        @media (max-width: 1024px) {
            .posts-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 520px) {
            .posts-grid {
                grid-template-columns: 1fr;
            }
            .post-card .post-img {
                height: 140px;
            }
        }

        /* steps */
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            counter-reset: step;
        }

        .step-card {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            padding: 32px 24px 28px;
            border: 1px solid var(--border-light);
            box-shadow: var(--shadow-card, 0 2px 12px rgba(0, 0, 0, 0.03));
            text-align: center;
            position: relative;
            transition: all var(--transition-smooth);
        }

        .step-card:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-card-hover, 0 12px 40px rgba(0, 0, 0, 0.06));
        }

        .step-card .step-number {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-light));
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 800;
            font-size: 1.1rem;
            margin: 0 auto 18px;
        }

        .step-card h3 {
            font-size: 1.1rem;
            font-weight: 700;
            margin-bottom: 8px;
            color: var(--text-primary);
        }

        .step-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            line-height: 1.6;
            margin: 0;
        }

        @media (max-width: 1024px) {
            .steps-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 520px) {
            .steps-grid {
                grid-template-columns: 1fr;
            }
        }

        /* FAQ */
        .faq-list {
            max-width: 720px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .faq-item {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            border: 1px solid var(--border-light);
            overflow: hidden;
            transition: all var(--transition-base);
        }

        .faq-item:hover {
            border-color: rgba(31, 122, 110, 0.10);
        }

        .faq-question {
            width: 100%;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 18px 24px;
            background: none;
            border: none;
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-primary);
            text-align: left;
            gap: 16px;
            transition: all var(--transition-base);
        }

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

        .faq-question i {
            font-size: 0.85rem;
            color: var(--text-muted);
            transition: transform var(--transition-smooth);
            flex-shrink: 0;
        }

        .faq-item.open .faq-question i {
            transform: rotate(180deg);
            color: var(--brand-primary);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height var(--transition-smooth), padding var(--transition-smooth);
            padding: 0 24px;
        }

        .faq-item.open .faq-answer {
            max-height: 300px;
            padding: 0 24px 20px;
        }

        .faq-answer p {
            margin: 0;
            font-size: 0.92rem;
            color: var(--text-secondary);
            line-height: 1.7;
        }

        @media (max-width: 520px) {
            .faq-question {
                padding: 14px 16px;
                font-size: 0.92rem;
            }
            .faq-answer {
                padding: 0 16px;
            }
            .faq-item.open .faq-answer {
                padding: 0 16px 16px;
            }
        }

        /* CTA */
        .cta-section {
            background: linear-gradient(135deg, #0a2724 0%, #1a5049 60%, #1f7a6e 100%);
            border-radius: var(--radius-lg);
            padding: 64px 48px;
            position: relative;
            overflow: hidden;
        }

        .cta-section::before {
            content: '';
            position: absolute;
            inset: 0;
            background-image: url('/assets/images/backpic/back-2.png');
            background-size: cover;
            background-position: center;
            opacity: 0.08;
            mix-blend-mode: overlay;
        }

        .cta-content {
            position: relative;
            z-index: 2;
            text-align: center;
            color: #fff;
        }

        .cta-content h2 {
            font-size: 2.2rem;
            font-weight: 800;
            margin-bottom: 16px;
            letter-spacing: -0.3px;
        }

        .cta-content p {
            font-size: 1.1rem;
            color: rgba(255, 255, 255, 0.7);
            max-width: 520px;
            margin: 0 auto 32px;
            line-height: 1.6;
        }

        .cta-content .btn-cta {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            padding: 16px 40px;
            background: #fff;
            color: var(--brand-primary-dark);
            border-radius: 12px;
            font-weight: 700;
            font-size: 1.05rem;
            border: none;
            transition: all var(--transition-smooth);
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
        }

        .cta-content .btn-cta:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 36px rgba(0, 0, 0, 0.20);
        }

        @media (max-width: 768px) {
            .cta-section {
                padding: 48px 24px;
            }
            .cta-content h2 {
                font-size: 1.6rem;
            }
            .cta-content p {
                font-size: 0.95rem;
            }
            .cta-content .btn-cta {
                padding: 14px 28px;
                font-size: 0.95rem;
            }
        }

        @media (max-width: 520px) {
            .cta-section {
                padding: 36px 16px;
                border-radius: var(--radius-md);
            }
            .cta-content h2 {
                font-size: 1.3rem;
            }
        }

        /* footer */
        .site-footer {
            background: #0d0f13;
            color: rgba(255, 255, 255, 0.7);
            padding: 56px 0 32px;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }

        .footer-brand .logo {
            font-size: 1.3rem;
            font-weight: 700;
            color: #fff;
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 14px;
        }

        .footer-brand .logo .logo-icon {
            width: 32px;
            height: 32px;
            background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-light));
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 0.9rem;
            font-weight: 800;
        }

        .footer-brand p {
            font-size: 0.9rem;
            line-height: 1.7;
            max-width: 320px;
            margin: 0 0 20px;
        }

        .footer-social {
            display: flex;
            gap: 12px;
        }

        .footer-social a {
            width: 38px;
            height: 38px;
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.06);
            display: flex;
            align-items: center;
            justify-content: center;
            color: rgba(255, 255, 255, 0.5);
            font-size: 1rem;
            transition: all var(--transition-base);
        }

        .footer-social a:hover {
            background: var(--brand-primary);
            color: #fff;
            transform: translateY(-2px);
        }

        .footer-col h4 {
            font-size: 0.95rem;
            font-weight: 700;
            color: #fff;
            margin-bottom: 16px;
        }

        .footer-col ul {
            list-style: none;
            padding: 0;
            margin: 0;
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .footer-col ul a {
            font-size: 0.88rem;
            color: rgba(255, 255, 255, 0.55);
            transition: color var(--transition-base);
        }

        .footer-col ul a:hover {
            color: var(--brand-primary-light);
        }

        .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.06);
            padding-top: 24px;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            gap: 12px;
            font-size: 0.82rem;
            color: rgba(255, 255, 255, 0.35);
        }

        .footer-bottom a {
            color: rgba(255, 255, 255, 0.35);
        }

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

        @media (max-width: 900px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 32px;
            }
            .footer-brand {
                grid-column: 1 / -1;
            }
        }

        @media (max-width: 520px) {
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 28px;
            }
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
        }

        /* skeleton / empty state */
        .empty-state {
            text-align: center;
            padding: 40px 20px;
            color: var(--text-muted);
            font-size: 0.95rem;
        }

        .empty-state i {
            font-size: 2.4rem;
            margin-bottom: 16px;
            display: block;
            color: var(--border-light);
        }

        /* extra utilities */
        .bg-alt {
            background: #f1f4f7;
        }

        .bg-white {
            background: #fff;
        }

        .rounded-card {
            border-radius: var(--radius-md);
        }

        .shadow-card {
            box-shadow: 0 2px 12px rgba(0, 0, 0, 0.03);
        }

        /* focus visible for accessibility */
        a:focus-visible,
        button:focus-visible,
        input:focus-visible {
            outline: 2px solid var(--brand-primary-light);
            outline-offset: 2px;
        }

        /* scroll margin for anchor offset */
        .section-anchor {
            scroll-margin-top: 80px;
        }

/* roulang page: category1 */
:root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --primary-light: #3b82f6;
            --primary-bg: #eff6ff;
            --accent: #0ea5e9;
            --accent-light: #e0f2fe;
            --success: #10b981;
            --warning: #f59e0b;
            --bg-body: #f8fafc;
            --bg-card: #ffffff;
            --text-primary: #0f172a;
            --text-secondary: #475569;
            --text-muted: #94a3b8;
            --border: #e2e8f0;
            --radius: 12px;
            --radius-sm: 8px;
            --radius-lg: 16px;
            --shadow: 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 40px rgba(0, 0, 0, 0.1);
            --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
            background: var(--bg-body);
            color: var(--text-primary);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

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

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

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

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        @media (max-width: 640px) {
            .container {
                padding: 0 16px;
            }
        }

        /* ===== Header & Nav ===== */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 50;
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid rgba(226, 232, 240, 0.7);
            box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
        }

        .nav-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 68px;
        }

        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.35rem;
            font-weight: 700;
            color: var(--text-primary);
            letter-spacing: -0.02em;
        }

        .nav-logo .logo-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 36px;
            height: 36px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: #fff;
            border-radius: 8px;
            font-size: 1.2rem;
            font-weight: 700;
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 4px;
            list-style: none;
        }

        .nav-links li a {
            display: block;
            padding: 8px 16px;
            font-size: 0.925rem;
            font-weight: 500;
            color: var(--text-secondary);
            border-radius: 6px;
            transition: var(--transition);
        }

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

        .nav-links li a.active {
            color: var(--primary);
            background: var(--primary-bg);
            font-weight: 600;
        }

        .nav-right {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .nav-search {
            display: flex;
            align-items: center;
            gap: 8px;
            background: #f1f5f9;
            border-radius: 8px;
            padding: 6px 14px;
            border: 1px solid transparent;
            transition: var(--transition);
            min-width: 180px;
        }

        .nav-search:focus-within {
            border-color: var(--primary);
            background: #fff;
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }

        .nav-search i {
            color: var(--text-muted);
            font-size: 0.9rem;
        }

        .nav-search input {
            border: none;
            background: transparent;
            outline: none;
            font-size: 0.875rem;
            color: var(--text-primary);
            width: 100%;
        }

        .nav-search input::placeholder {
            color: var(--text-muted);
        }

        .nav-cta {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 9px 20px;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: #fff;
            border-radius: 8px;
            font-size: 0.875rem;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
        }

        .nav-cta:hover {
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35);
        }

        .nav-mobile-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.4rem;
            color: var(--text-primary);
            cursor: pointer;
            padding: 4px 8px;
            border-radius: 6px;
            transition: var(--transition);
        }

        .nav-mobile-toggle:hover {
            background: #f1f5f9;
        }

        @media (max-width: 768px) {
            .nav-links {
                position: fixed;
                top: 68px;
                left: 0;
                right: 0;
                background: rgba(255, 255, 255, 0.98);
                backdrop-filter: blur(16px);
                flex-direction: column;
                padding: 16px 24px;
                gap: 4px;
                border-bottom: 1px solid var(--border);
                transform: translateY(-120%);
                opacity: 0;
                pointer-events: none;
                transition: var(--transition);
                box-shadow: var(--shadow-md);
                z-index: 40;
            }

            .nav-links.open {
                transform: translateY(0);
                opacity: 1;
                pointer-events: auto;
            }

            .nav-links li a {
                padding: 12px 16px;
                font-size: 1rem;
            }

            .nav-search {
                min-width: unset;
                flex: 0 1 140px;
            }

            .nav-cta span {
                display: none;
            }

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

        @media (max-width: 480px) {
            .nav-container {
                padding: 0 12px;
                height: 60px;
            }
            .nav-logo {
                font-size: 1.15rem;
            }
            .nav-logo .logo-icon {
                width: 30px;
                height: 30px;
                font-size: 1rem;
            }
            .nav-search {
                min-width: unset;
                width: 36px;
                padding: 6px 8px;
                justify-content: center;
            }
            .nav-search input {
                display: none;
            }
            .nav-cta {
                padding: 8px 12px;
            }
        }

        /* ===== Page Banner ===== */
        .page-banner {
            position: relative;
            padding: 80px 0 64px;
            background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #0f172a 100%);
            overflow: hidden;
            min-height: 280px;
            display: flex;
            align-items: center;
        }

        .page-banner::before {
            content: '';
            position: absolute;
            inset: 0;
            background: url('/assets/images/backpic/back-2.png') center center / cover no-repeat;
            opacity: 0.15;
            mix-blend-mode: overlay;
        }

        .page-banner::after {
            content: '';
            position: absolute;
            top: -40%;
            right: -10%;
            width: 500px;
            height: 500px;
            background: radial-gradient(circle, rgba(37, 99, 235, 0.15) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }

        .page-banner .container {
            position: relative;
            z-index: 2;
            text-align: center;
        }

        .page-banner h1 {
            font-size: 2.6rem;
            font-weight: 800;
            color: #fff;
            letter-spacing: -0.02em;
            line-height: 1.2;
            margin-bottom: 16px;
        }

        .page-banner p {
            font-size: 1.1rem;
            color: rgba(255, 255, 255, 0.75);
            max-width: 640px;
            margin: 0 auto 20px;
            line-height: 1.7;
        }

        .page-banner .banner-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(4px);
            border: 1px solid rgba(255, 255, 255, 0.15);
            padding: 6px 18px;
            border-radius: 40px;
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.9);
            margin-bottom: 20px;
        }

        .page-banner .banner-badge i {
            color: var(--accent);
        }

        @media (max-width: 768px) {
            .page-banner {
                padding: 56px 0 48px;
                min-height: 220px;
            }
            .page-banner h1 {
                font-size: 1.8rem;
            }
            .page-banner p {
                font-size: 0.95rem;
            }
        }

        @media (max-width: 480px) {
            .page-banner h1 {
                font-size: 1.5rem;
            }
            .page-banner p {
                font-size: 0.875rem;
            }
            .page-banner .banner-badge {
                font-size: 0.75rem;
                padding: 4px 14px;
            }
        }

        /* ===== Section Common ===== */
        .section {
            padding: 72px 0;
        }

        @media (max-width: 768px) {
            .section {
                padding: 48px 0;
            }
        }

        .section-label {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            font-size: 0.8rem;
            font-weight: 600;
            color: var(--primary);
            background: var(--primary-bg);
            padding: 4px 14px;
            border-radius: 40px;
            letter-spacing: 0.3px;
            margin-bottom: 12px;
        }

        .section-title {
            font-size: 2rem;
            font-weight: 700;
            color: var(--text-primary);
            letter-spacing: -0.02em;
            line-height: 1.25;
            margin-bottom: 16px;
        }

        .section-sub {
            font-size: 1.05rem;
            color: var(--text-secondary);
            max-width: 600px;
            line-height: 1.7;
        }

        @media (max-width: 768px) {
            .section-title {
                font-size: 1.5rem;
            }
            .section-sub {
                font-size: 0.925rem;
            }
        }

        /* ===== Guide Steps ===== */
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 28px;
            margin-top: 40px;
        }

        .step-card {
            background: var(--bg-card);
            border-radius: var(--radius);
            padding: 32px 24px;
            text-align: center;
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            transition: var(--transition);
            position: relative;
        }

        .step-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
            border-color: var(--primary-light);
        }

        .step-number {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 48px;
            height: 48px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: #fff;
            border-radius: 50%;
            font-size: 1.2rem;
            font-weight: 700;
            margin-bottom: 18px;
        }

        .step-card h3 {
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 10px;
        }

        .step-card p {
            font-size: 0.925rem;
            color: var(--text-secondary);
            line-height: 1.6;
        }

        /* ===== Features / Cards ===== */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 24px;
            margin-top: 40px;
        }

        .feature-card {
            background: var(--bg-card);
            border-radius: var(--radius);
            padding: 28px 24px;
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            transition: var(--transition);
        }

        .feature-card:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-md);
            border-color: var(--primary-light);
        }

        .feature-card .fc-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 44px;
            height: 44px;
            background: var(--primary-bg);
            color: var(--primary);
            border-radius: 10px;
            font-size: 1.2rem;
            margin-bottom: 16px;
        }

        .feature-card h3 {
            font-size: 1.05rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 8px;
        }

        .feature-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            line-height: 1.65;
        }

        .feature-card .tag {
            display: inline-block;
            font-size: 0.7rem;
            font-weight: 600;
            color: var(--primary);
            background: var(--primary-bg);
            padding: 2px 10px;
            border-radius: 40px;
            margin-top: 12px;
        }

        /* ===== Content List ===== */
        .content-list {
            display: flex;
            flex-direction: column;
            gap: 16px;
            margin-top: 36px;
        }

        .content-item {
            display: flex;
            align-items: center;
            gap: 20px;
            background: var(--bg-card);
            border-radius: var(--radius-sm);
            padding: 20px 24px;
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            transition: var(--transition);
            cursor: default;
        }

        .content-item:hover {
            box-shadow: var(--shadow-md);
            border-color: var(--primary-light);
            transform: translateX(4px);
        }

        .content-item .ci-img {
            flex-shrink: 0;
            width: 88px;
            height: 88px;
            border-radius: 8px;
            overflow: hidden;
            background: #f1f5f9;
        }

        .content-item .ci-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .content-item .ci-body {
            flex: 1;
            min-width: 0;
        }

        .content-item .ci-body h3 {
            font-size: 1.05rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 4px;
        }

        .content-item .ci-body p {
            font-size: 0.875rem;
            color: var(--text-secondary);
            line-height: 1.6;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .content-item .ci-meta {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-top: 8px;
            font-size: 0.75rem;
            color: var(--text-muted);
        }

        .content-item .ci-meta i {
            margin-right: 4px;
        }

        .content-item .ci-tag {
            flex-shrink: 0;
            font-size: 0.7rem;
            font-weight: 600;
            color: var(--primary);
            background: var(--primary-bg);
            padding: 4px 12px;
            border-radius: 40px;
            white-space: nowrap;
        }

        @media (max-width: 640px) {
            .content-item {
                flex-direction: column;
                align-items: flex-start;
                padding: 16px;
            }
            .content-item .ci-img {
                width: 100%;
                height: 160px;
            }
            .content-item .ci-tag {
                align-self: flex-start;
                margin-top: 8px;
            }
        }

        /* ===== Video / Media Card ===== */
        .video-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
            gap: 24px;
            margin-top: 40px;
        }

        .video-card {
            background: var(--bg-card);
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            transition: var(--transition);
        }

        .video-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
            border-color: var(--primary-light);
        }

        .video-card .vc-img {
            position: relative;
            width: 100%;
            aspect-ratio: 16 / 9;
            overflow: hidden;
            background: #e2e8f0;
        }

        .video-card .vc-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }

        .video-card:hover .vc-img img {
            transform: scale(1.03);
        }

        .video-card .vc-img .play-btn {
            position: absolute;
            inset: 0;
            display: flex;
            align-items: center;
            justify-content: center;
            background: rgba(0, 0, 0, 0.2);
            transition: var(--transition);
        }

        .video-card .vc-img .play-btn i {
            font-size: 2.8rem;
            color: rgba(255, 255, 255, 0.9);
            background: rgba(0, 0, 0, 0.4);
            border-radius: 50%;
            padding: 14px;
            backdrop-filter: blur(2px);
            transition: var(--transition);
        }

        .video-card:hover .vc-img .play-btn i {
            background: rgba(37, 99, 235, 0.8);
            transform: scale(1.05);
        }

        .video-card .vc-body {
            padding: 18px 20px 22px;
        }

        .video-card .vc-body h3 {
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 6px;
        }

        .video-card .vc-body p {
            font-size: 0.85rem;
            color: var(--text-secondary);
            line-height: 1.6;
        }

        .video-card .vc-body .vc-meta {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-top: 10px;
            font-size: 0.75rem;
            color: var(--text-muted);
        }

        /* ===== FAQ ===== */
        .faq-grid {
            max-width: 800px;
            margin: 36px auto 0;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .faq-item {
            background: var(--bg-card);
            border-radius: var(--radius-sm);
            border: 1px solid var(--border);
            overflow: hidden;
            transition: var(--transition);
        }

        .faq-item:hover {
            border-color: var(--primary-light);
        }

        .faq-question {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 18px 24px;
            font-size: 1rem;
            font-weight: 500;
            color: var(--text-primary);
            cursor: pointer;
            transition: var(--transition);
            background: none;
            border: none;
            width: 100%;
            text-align: left;
            gap: 12px;
        }

        .faq-question:hover {
            background: #f8fafc;
        }

        .faq-question i {
            color: var(--text-muted);
            transition: var(--transition);
            font-size: 0.9rem;
            flex-shrink: 0;
        }

        .faq-question.open i {
            transform: rotate(180deg);
            color: var(--primary);
        }

        .faq-answer {
            padding: 0 24px 18px;
            font-size: 0.925rem;
            color: var(--text-secondary);
            line-height: 1.7;
            display: none;
        }

        .faq-answer.open {
            display: block;
        }

        /* ===== CTA ===== */
        .cta-section {
            background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #0f172a 100%);
            padding: 64px 0;
            position: relative;
            overflow: hidden;
        }

        .cta-section::before {
            content: '';
            position: absolute;
            inset: 0;
            background: url('/assets/images/backpic/back-3.png') center center / cover no-repeat;
            opacity: 0.08;
            mix-blend-mode: overlay;
        }

        .cta-section .container {
            position: relative;
            z-index: 2;
            text-align: center;
        }

        .cta-section h2 {
            font-size: 2rem;
            font-weight: 700;
            color: #fff;
            letter-spacing: -0.02em;
            margin-bottom: 12px;
        }

        .cta-section p {
            font-size: 1.05rem;
            color: rgba(255, 255, 255, 0.7);
            max-width: 520px;
            margin: 0 auto 28px;
        }

        .cta-section .cta-btn {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            padding: 14px 36px;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: #fff;
            border-radius: 10px;
            font-size: 1rem;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
        }

        .cta-section .cta-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 30px rgba(37, 99, 235, 0.5);
        }

        @media (max-width: 768px) {
            .cta-section {
                padding: 48px 0;
            }
            .cta-section h2 {
                font-size: 1.5rem;
            }
            .cta-section p {
                font-size: 0.925rem;
            }
            .cta-section .cta-btn {
                padding: 12px 28px;
                font-size: 0.9rem;
            }
        }

        /* ===== Footer ===== */
        .site-footer {
            background: #0f172a;
            color: rgba(255, 255, 255, 0.8);
            padding: 56px 0 0;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 1.6fr 1fr 1fr 1fr;
            gap: 40px;
            padding-bottom: 40px;
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        }

        .footer-brand .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.3rem;
            font-weight: 700;
            color: #fff;
            margin-bottom: 16px;
        }

        .footer-brand .logo .logo-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 36px;
            height: 36px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: #fff;
            border-radius: 8px;
            font-size: 1.2rem;
            font-weight: 700;
        }

        .footer-brand p {
            font-size: 0.875rem;
            line-height: 1.7;
            color: rgba(255, 255, 255, 0.55);
            max-width: 320px;
        }

        .footer-social {
            display: flex;
            gap: 12px;
            margin-top: 18px;
        }

        .footer-social a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 38px;
            height: 38px;
            border-radius: 8px;
            background: rgba(255, 255, 255, 0.06);
            color: rgba(255, 255, 255, 0.6);
            font-size: 1.1rem;
            transition: var(--transition);
        }

        .footer-social a:hover {
            background: var(--primary);
            color: #fff;
            transform: translateY(-2px);
        }

        .footer-col h4 {
            font-size: 0.9rem;
            font-weight: 600;
            color: #fff;
            margin-bottom: 16px;
            letter-spacing: 0.3px;
        }

        .footer-col ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .footer-col ul li a {
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.55);
            transition: var(--transition);
        }

        .footer-col ul li a:hover {
            color: #fff;
            padding-left: 4px;
        }

        .footer-bottom {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 20px 0;
            font-size: 0.8rem;
            color: rgba(255, 255, 255, 0.35);
            flex-wrap: wrap;
            gap: 8px;
        }

        .footer-bottom a {
            color: rgba(255, 255, 255, 0.5);
        }

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

        @media (max-width: 768px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 32px;
            }
            .footer-brand {
                grid-column: 1 / -1;
            }
        }

        @media (max-width: 480px) {
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 24px;
            }
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
        }

        /* ===== Mobile nav open class ===== */
        .nav-links.open {
            transform: translateY(0) !important;
            opacity: 1 !important;
            pointer-events: auto !important;
        }

        /* ===== Smooth stagger ===== */
        .stagger-fade {
            opacity: 0;
            transform: translateY(20px);
            animation: fadeUp 0.5s ease forwards;
        }

        @keyframes fadeUp {
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .stagger-fade:nth-child(1) {
            animation-delay: 0.05s;
        }
        .stagger-fade:nth-child(2) {
            animation-delay: 0.1s;
        }
        .stagger-fade:nth-child(3) {
            animation-delay: 0.15s;
        }
        .stagger-fade:nth-child(4) {
            animation-delay: 0.2s;
        }
        .stagger-fade:nth-child(5) {
            animation-delay: 0.25s;
        }
        .stagger-fade:nth-child(6) {
            animation-delay: 0.3s;
        }
        .stagger-fade:nth-child(7) {
            animation-delay: 0.35s;
        }
        .stagger-fade:nth-child(8) {
            animation-delay: 0.4s;
        }

/* roulang page: article */
:root {
            --primary: #2d7eff;
            --primary-dark: #1a5eff;
            --accent: #16b873;
            --accent-dark: #0a965d;
            --bg-body: #f8f9fa;
            --bg-card: #ffffff;
            --text-primary: #212529;
            --text-secondary: #495057;
            --text-muted: #868e96;
            --border-light: #e9ecef;
            --border-medium: #dee2e6;
            --radius-sm: 0.5rem;
            --radius-md: 0.75rem;
            --radius-lg: 1rem;
            --radius-xl: 1.5rem;
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.04);
            --shadow-md: 0 4px 16px rgba(0,0,0,0.06);
            --shadow-lg: 0 8px 32px rgba(0,0,0,0.10);
            --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body { font-family: 'PingFang SC','Microsoft YaHei','Helvetica Neue',Arial,sans-serif; background: var(--bg-body); color: var(--text-primary); line-height: 1.7; -webkit-font-smoothing: antialiased; }
        img { max-width: 100%; height: auto; display: block; }
        a { color: inherit; text-decoration: none; transition: var(--transition); }
        button { cursor: pointer; font-family: inherit; border: none; background: none; }
        input { font-family: inherit; outline: none; border: none; }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
        .container-narrow { max-width: 860px; margin: 0 auto; padding: 0 24px; }

        /* Header & Navigation */
        .site-header { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; background: rgba(255,255,255,0.92); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border-bottom: 1px solid rgba(222,226,230,0.5); transition: var(--transition); }
        .site-header.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
        .nav-container { max-width: 1200px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; height: 68px; }
        .nav-logo { display: flex; align-items: center; gap: 8px; font-size: 1.35rem; font-weight: 700; color: var(--text-primary); letter-spacing: -0.3px; }
        .nav-logo .logo-icon { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; border-radius: var(--radius-sm); font-size: 1.1rem; font-weight: 800; }
        .nav-links { display: flex; align-items: center; gap: 4px; list-style: none; margin: 0; padding: 0; }
        .nav-links li a { display: block; padding: 8px 18px; font-size: 0.94rem; font-weight: 500; color: var(--text-secondary); border-radius: var(--radius-sm); transition: var(--transition); position: relative; }
        .nav-links li a:hover { color: var(--primary); background: rgba(45,126,255,0.06); }
        .nav-links li a.active { color: var(--primary); background: rgba(45,126,255,0.10); font-weight: 600; }
        .nav-links li a.active::after { content: ''; position: absolute; bottom: 2px; left: 50%; transform: translateX(-50%); width: 20px; height: 3px; background: var(--primary); border-radius: 4px; }
        .nav-right { display: flex; align-items: center; gap: 12px; }
        .nav-search { display: flex; align-items: center; gap: 8px; background: var(--bg-body); border: 1px solid var(--border-light); border-radius: 100px; padding: 6px 16px; transition: var(--transition); min-width: 160px; }
        .nav-search:focus-within { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(45,126,255,0.12); }
        .nav-search i { color: var(--text-muted); font-size: 0.9rem; }
        .nav-search input { background: transparent; border: none; font-size: 0.88rem; color: var(--text-primary); width: 100%; padding: 4px 0; }
        .nav-search input::placeholder { color: var(--text-muted); }
        .nav-cta { display: inline-flex; align-items: center; gap: 6px; padding: 9px 22px; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; border-radius: 100px; font-size: 0.9rem; font-weight: 600; transition: var(--transition); box-shadow: 0 2px 12px rgba(45,126,255,0.25); }
        .nav-cta:hover { transform: translateY(-1px); box-shadow: 0 6px 24px rgba(45,126,255,0.35); color: #fff; }
        .nav-cta i { font-size: 0.85rem; }
        .nav-mobile-toggle { display: none; align-items: center; justify-content: center; width: 40px; height: 40px; border-radius: var(--radius-sm); background: var(--bg-body); border: 1px solid var(--border-light); font-size: 1.2rem; color: var(--text-secondary); transition: var(--transition); }
        .nav-mobile-toggle:hover { background: var(--border-light); }

        /* Article Hero */
        .article-hero { padding: 120px 0 60px; background: linear-gradient(135deg, #f0f4ff 0%, #e8f0fe 50%, #f5f0ff 100%); position: relative; overflow: hidden; }
        .article-hero::before { content: ''; position: absolute; top: -60%; right: -20%; width: 500px; height: 500px; background: radial-gradient(circle, rgba(45,126,255,0.06) 0%, transparent 70%); border-radius: 50%; pointer-events: none; }
        .article-hero::after { content: ''; position: absolute; bottom: -30%; left: -10%; width: 400px; height: 400px; background: radial-gradient(circle, rgba(22,184,115,0.05) 0%, transparent 70%); border-radius: 50%; pointer-events: none; }
        .article-hero .container-narrow { position: relative; z-index: 1; }
        .article-breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 24px; }
        .article-breadcrumb a { color: var(--primary); font-weight: 500; }
        .article-breadcrumb a:hover { text-decoration: underline; }
        .article-breadcrumb span { color: var(--text-muted); }
        .article-hero h1 { font-size: 2.4rem; font-weight: 800; line-height: 1.3; color: var(--text-primary); margin-bottom: 20px; letter-spacing: -0.5px; }
        .article-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 16px 28px; font-size: 0.9rem; color: var(--text-muted); }
        .article-meta .meta-item { display: flex; align-items: center; gap: 6px; }
        .article-meta .meta-item i { font-size: 0.85rem; }
        .article-meta .category-tag { display: inline-block; padding: 3px 14px; background: rgba(45,126,255,0.10); color: var(--primary); border-radius: 100px; font-size: 0.82rem; font-weight: 600; }

        /* Article Content */
        .article-content-section { padding: 60px 0 80px; }
        .article-body { background: var(--bg-card); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); padding: 48px 56px; border: 1px solid var(--border-light); }
        .article-body .content { font-size: 1.05rem; line-height: 1.9; color: var(--text-secondary); }
        .article-body .content p { margin-bottom: 1.4em; }
        .article-body .content h2 { font-size: 1.6rem; font-weight: 700; color: var(--text-primary); margin: 1.8em 0 0.8em; letter-spacing: -0.3px; }
        .article-body .content h3 { font-size: 1.25rem; font-weight: 600; color: var(--text-primary); margin: 1.6em 0 0.6em; }
        .article-body .content ul, .article-body .content ol { margin-bottom: 1.4em; padding-left: 1.6em; }
        .article-body .content li { margin-bottom: 0.4em; }
        .article-body .content img { border-radius: var(--radius-md); margin: 1.6em 0; box-shadow: var(--shadow-sm); }
        .article-body .content blockquote { border-left: 4px solid var(--primary); padding: 12px 20px; margin: 1.4em 0; background: rgba(45,126,255,0.04); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; color: var(--text-secondary); font-style: normal; }
        .article-body .content a { color: var(--primary); text-decoration: underline; text-underline-offset: 3px; font-weight: 500; }
        .article-body .content a:hover { color: var(--primary-dark); }
        .article-body .content code { background: var(--bg-body); padding: 2px 8px; border-radius: 4px; font-size: 0.9em; border: 1px solid var(--border-light); }
        .article-body .content pre { background: var(--bg-body); border-radius: var(--radius-md); padding: 20px 24px; overflow-x: auto; border: 1px solid var(--border-light); margin-bottom: 1.4em; }

        .article-footer-nav { display: flex; justify-content: space-between; align-items: center; margin-top: 40px; padding-top: 28px; border-top: 1px solid var(--border-light); flex-wrap: wrap; gap: 16px; }
        .article-footer-nav .btn-back { display: inline-flex; align-items: center; gap: 8px; padding: 10px 24px; background: var(--bg-body); border: 1px solid var(--border-light); border-radius: 100px; font-size: 0.9rem; font-weight: 500; color: var(--text-secondary); transition: var(--transition); }
        .article-footer-nav .btn-back:hover { border-color: var(--primary); color: var(--primary); background: rgba(45,126,255,0.04); }
        .article-footer-nav .share-links { display: flex; align-items: center; gap: 10px; }
        .article-footer-nav .share-links span { font-size: 0.88rem; color: var(--text-muted); }
        .article-footer-nav .share-links a { display: inline-flex; align-items: center; justify-content: center; width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--border-light); color: var(--text-muted); transition: var(--transition); font-size: 0.95rem; }
        .article-footer-nav .share-links a:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

        /* Related Articles */
        .related-section { padding: 0 0 80px; }
        .related-section .section-title { font-size: 1.6rem; font-weight: 700; color: var(--text-primary); margin-bottom: 8px; letter-spacing: -0.3px; }
        .related-section .section-subtitle { font-size: 1rem; color: var(--text-muted); margin-bottom: 32px; }
        .related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
        .related-card { background: var(--bg-card); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); border: 1px solid var(--border-light); overflow: hidden; transition: var(--transition); display: flex; flex-direction: column; }
        .related-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: rgba(45,126,255,0.15); }
        .related-card .card-img { height: 180px; background: var(--border-light); overflow: hidden; }
        .related-card .card-img img { width: 100%; height: 100%; object-fit: cover; transition: var(--transition); }
        .related-card:hover .card-img img { transform: scale(1.04); }
        .related-card .card-body { padding: 20px 22px; flex: 1; display: flex; flex-direction: column; }
        .related-card .card-body h3 { font-size: 1.08rem; font-weight: 600; color: var(--text-primary); margin-bottom: 8px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
        .related-card .card-body p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; margin-bottom: 12px; flex: 1; }
        .related-card .card-meta { display: flex; align-items: center; justify-content: space-between; font-size: 0.82rem; color: var(--text-muted); }
        .related-card .card-meta .cat { display: inline-block; padding: 2px 12px; background: rgba(45,126,255,0.08); color: var(--primary); border-radius: 100px; font-size: 0.78rem; font-weight: 600; }

        /* Not Found */
        .not-found-block { text-align: center; padding: 80px 20px; }
        .not-found-block .nf-icon { font-size: 4rem; color: var(--text-muted); margin-bottom: 20px; opacity: 0.5; }
        .not-found-block h2 { font-size: 1.6rem; font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
        .not-found-block p { color: var(--text-muted); margin-bottom: 24px; font-size: 1.05rem; }
        .not-found-block .btn-home { display: inline-flex; align-items: center; gap: 8px; padding: 12px 32px; background: var(--primary); color: #fff; border-radius: 100px; font-weight: 600; transition: var(--transition); }
        .not-found-block .btn-home:hover { background: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 6px 24px rgba(45,126,255,0.30); }

        /* Footer */
        .site-footer { background: #1a1d23; color: #e9ecef; padding: 64px 0 0; }
        .site-footer .footer-grid { display: grid; grid-template-columns: 1.8fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,0.06); }
        .site-footer .footer-brand .logo { display: flex; align-items: center; gap: 8px; font-size: 1.3rem; font-weight: 700; color: #fff; margin-bottom: 16px; }
        .site-footer .footer-brand .logo .logo-icon { display: inline-flex; align-items: center; justify-content: center; width: 34px; height: 34px; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; border-radius: var(--radius-sm); font-size: 1rem; font-weight: 800; }
        .site-footer .footer-brand p { font-size: 0.9rem; color: #adb5bd; line-height: 1.7; max-width: 360px; margin-bottom: 20px; }
        .site-footer .footer-social { display: flex; gap: 12px; }
        .site-footer .footer-social a { display: inline-flex; align-items: center; justify-content: center; width: 38px; height: 38px; border-radius: 50%; background: rgba(255,255,255,0.06); color: #adb5bd; font-size: 1rem; transition: var(--transition); }
        .site-footer .footer-social a:hover { background: var(--primary); color: #fff; }
        .site-footer .footer-col h4 { font-size: 0.95rem; font-weight: 600; color: #fff; margin-bottom: 18px; letter-spacing: 0.3px; }
        .site-footer .footer-col ul { list-style: none; padding: 0; margin: 0; }
        .site-footer .footer-col ul li { margin-bottom: 10px; }
        .site-footer .footer-col ul li a { font-size: 0.88rem; color: #adb5bd; transition: var(--transition); }
        .site-footer .footer-col ul li a:hover { color: #fff; padding-left: 4px; }
        .site-footer .footer-bottom { display: flex; align-items: center; justify-content: space-between; padding: 20px 0; font-size: 0.84rem; color: #6c757d; flex-wrap: wrap; gap: 8px; }
        .site-footer .footer-bottom a { color: #adb5bd; }
        .site-footer .footer-bottom a:hover { color: #fff; }

        /* Responsive */
        @media (max-width: 1024px) {
            .related-grid { grid-template-columns: repeat(2, 1fr); }
            .article-body { padding: 36px 32px; }
        }
        @media (max-width: 768px) {
            .nav-links { display: none; position: absolute; top: 68px; left: 0; right: 0; background: rgba(255,255,255,0.98); backdrop-filter: blur(16px); flex-direction: column; padding: 16px 24px; border-bottom: 1px solid var(--border-light); box-shadow: 0 8px 32px rgba(0,0,0,0.08); }
            .nav-links.open { display: flex; }
            .nav-links li a { padding: 12px 16px; width: 100%; border-radius: var(--radius-sm); }
            .nav-links li a.active::after { display: none; }
            .nav-mobile-toggle { display: flex; }
            .nav-search { min-width: 120px; }
            .nav-search input { width: 60px; }
            .nav-search:focus-within input { width: 100%; }
            .nav-cta span { display: none; }
            .nav-cta { padding: 9px 14px; }
            .article-hero h1 { font-size: 1.7rem; }
            .article-hero { padding: 100px 0 40px; }
            .article-body { padding: 28px 20px; border-radius: var(--radius-md); }
            .article-body .content { font-size: 1rem; }
            .article-body .content h2 { font-size: 1.35rem; }
            .related-grid { grid-template-columns: 1fr; }
            .article-footer-nav { flex-direction: column; align-items: flex-start; }
            .site-footer .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
            .site-footer .footer-brand p { max-width: 100%; }
        }
        @media (max-width: 520px) {
            .nav-container { padding: 0 16px; height: 60px; }
            .nav-logo { font-size: 1.15rem; }
            .nav-logo .logo-icon { width: 30px; height: 30px; font-size: 0.9rem; }
            .nav-search { min-width: 40px; padding: 6px 10px; }
            .nav-search input { width: 0; padding: 0; }
            .nav-search:focus-within { min-width: 140px; }
            .nav-search:focus-within input { width: 100%; padding: 4px 0; }
            .article-hero h1 { font-size: 1.4rem; }
            .article-meta { gap: 10px 16px; font-size: 0.82rem; }
            .article-body { padding: 20px 16px; }
            .article-body .content h2 { font-size: 1.2rem; }
            .article-body .content h3 { font-size: 1.08rem; }
            .related-section .section-title { font-size: 1.3rem; }
            .site-footer .footer-grid { grid-template-columns: 1fr; gap: 28px; }
            .site-footer { padding: 40px 0 0; }
            .site-footer .footer-bottom { flex-direction: column; text-align: center; }
        }