/* roulang page: index */
:root {
            --primary: #141827;
            --secondary: #00C2A8;
            --accent: #FF5A3C;
            --bg: #F4F7FA;
            --card: #FFFFFF;
            --text: #1A1D29;
            --text-secondary: #5B6270;
            --border: #E6E9F0;
            --radius-card: 14px;
            --radius-btn: 10px;
            --shadow-default: 0 6px 24px rgba(20,24,40,.05);
            --shadow-hover: 0 12px 32px rgba(20,24,40,.12);
            --font-stack: 'PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,-apple-system,BlinkMacSystemFont,sans-serif;
            --transition: all .22s ease;
            --max-width: 1200px;
            --nav-height: 72px;
        }
        
        *,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
        
        html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
        
        body {
            font-family: var(--font-stack);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        
        img { max-width: 100%; height: auto; display: block; }
        a { text-decoration: none; color: inherit; transition: var(--transition); }
        button { font-family: inherit; cursor: pointer; border: none; background: none; }
        input,textarea,select { font-family: inherit; font-size: 16px; }
        ul,ol { list-style: none; }
        
        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        
        /* Header / Navigation */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            height: var(--nav-height);
            background: rgba(255,255,255,.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            transition: var(--transition);
        }
        
        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 18px;
            color: var(--primary);
            letter-spacing: .3px;
            flex-shrink: 0;
        }
        
        .logo-icon {
            width: 38px;
            height: 38px;
            border-radius: 9px;
            background: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
            font-weight: 800;
            flex-shrink: 0;
        }
        
        .logo span { white-space: nowrap; }
        
        .main-nav {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        
        .main-nav a {
            display: inline-flex;
            align-items: center;
            padding: 8px 16px;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            position: relative;
            transition: var(--transition);
            white-space: nowrap;
        }
        
        .main-nav a:hover {
            color: var(--secondary);
            background: rgba(0,194,168,.06);
        }
        
        .main-nav a.active {
            color: var(--accent);
            font-weight: 600;
        }
        
        .main-nav a.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 16px;
            right: 16px;
            height: 3px;
            border-radius: 2px;
            background: var(--accent);
        }
        
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            padding: 8px;
            border-radius: 8px;
            transition: var(--transition);
            z-index: 1100;
        }
        
        .hamburger span {
            display: block;
            width: 24px;
            height: 2.5px;
            background: var(--primary);
            border-radius: 2px;
            transition: var(--transition);
        }
        
        .hamburger.open span:nth-child(1) {
            transform: translateY(7.5px) rotate(45deg);
        }
        
        .hamburger.open span:nth-child(2) {
            opacity: 0;
        }
        
        .hamburger.open span:nth-child(3) {
            transform: translateY(-7.5px) rotate(-45deg);
        }
        
        .mobile-overlay {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(20,24,40,.55);
            z-index: 1050;
            opacity: 0;
            transition: opacity .25s ease;
        }
        
        .mobile-overlay.show {
            opacity: 1;
        }
        
        .mobile-drawer {
            position: fixed;
            top: 0;
            right: -320px;
            width: 300px;
            max-width: 85vw;
            height: 100vh;
            background: #fff;
            z-index: 1060;
            padding: 80px 24px 40px;
            display: flex;
            flex-direction: column;
            transition: right .3s ease;
            box-shadow: -8px 0 40px rgba(20,24,40,.1);
        }
        
        .mobile-drawer.open {
            right: 0;
        }
        
        .mobile-drawer a {
            display: block;
            padding: 14px 16px;
            font-size: 16px;
            font-weight: 500;
            color: var(--text);
            border-radius: 10px;
            transition: var(--transition);
        }
        
        .mobile-drawer a:hover {
            background: var(--bg);
            color: var(--secondary);
        }
        
        .mobile-drawer a.active {
            color: var(--accent);
            font-weight: 600;
            background: rgba(255,90,60,.06);
        }
        
        /* Hero */
        .hero {
            background: var(--primary);
            color: #fff;
            padding: 80px 0 90px;
            position: relative;
            overflow: hidden;
        }
        
        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background-image: 
                linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px);
            background-size: 48px 48px;
            pointer-events: none;
        }
        
        .hero::after {
            content: '';
            position: absolute;
            top: -120px;
            right: -80px;
            width: 480px;
            height: 480px;
            background: radial-gradient(circle, rgba(0,194,168,.16) 0%, transparent 65%);
            border-radius: 50%;
            pointer-events: none;
        }
        
        .hero .container {
            display: grid;
            grid-template-columns: 52% 48%;
            gap: 48px;
            align-items: center;
            position: relative;
            z-index: 2;
        }
        
        .hero-content h1 {
            font-size: 38px;
            font-weight: 700;
            line-height: 1.3;
            margin-bottom: 20px;
            letter-spacing: .5px;
        }
        
        .hero-content .hero-sub {
            font-size: 17px;
            color: rgba(255,255,255,.8);
            line-height: 1.75;
            margin-bottom: 32px;
            max-width: 520px;
        }
        
        .hero-cta {
            display: flex;
            gap: 14px;
            flex-wrap: wrap;
        }
        
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 14px 28px;
            border-radius: var(--radius-btn);
            font-size: 15px;
            font-weight: 600;
            transition: var(--transition);
            letter-spacing: .3px;
            line-height: 1.4;
            min-height: 48px;
        }
        
        .btn:focus-visible {
            outline: 3px solid rgba(0,194,168,.5);
            outline-offset: 2px;
        }
        
        .btn:active {
            transform: translateY(0);
        }
        
        .btn-accent {
            background: var(--accent);
            color: #fff;
        }
        
        .btn-accent:hover {
            background: #e84a2e;
            transform: translateY(-1px);
            box-shadow: 0 8px 24px rgba(255,90,60,.3);
        }
        
        .btn-outline-light {
            background: transparent;
            color: #fff;
            border: 1.5px solid rgba(255,255,255,.4);
        }
        
        .btn-outline-light:hover {
            border-color: rgba(255,255,255,.8);
            background: rgba(255,255,255,.06);
            transform: translateY(-1px);
        }
        
        .btn-secondary {
            background: var(--secondary);
            color: #fff;
        }
        
        .btn-secondary:hover {
            background: #00a890;
            transform: translateY(-1px);
            box-shadow: 0 8px 24px rgba(0,194,168,.3);
        }
        
        .btn-outline {
            background: transparent;
            color: var(--primary);
            border: 1.5px solid var(--border);
        }
        
        .btn-outline:hover {
            border-color: var(--secondary);
            color: var(--secondary);
            transform: translateY(-1px);
        }
        
        .btn-sm {
            padding: 10px 18px;
            min-height: 40px;
            font-size: 13px;
            border-radius: 8px;
        }
        
        .hero-visual {
            position: relative;
            border-radius: 16px;
            overflow: hidden;
            box-shadow: 0 24px 60px rgba(0,0,0,.35);
            aspect-ratio: 16/10;
            background: rgba(255,255,255,.05);
            border: 1px solid rgba(255,255,255,.1);
        }
        
        .hero-visual img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        
        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 6px 14px;
            border-radius: 100px;
            background: rgba(0,194,168,.15);
            color: var(--secondary);
            font-size: 13px;
            font-weight: 600;
            margin-bottom: 18px;
            letter-spacing: .5px;
        }
        
        /* Section general */
        section { padding: 72px 0; }
        section.alt-bg { background: #fff; }
        section.dark-bg { background: var(--primary); color: #fff; }
        
        .section-header {
            margin-bottom: 40px;
        }
        
        .section-header h2 {
            font-size: 28px;
            font-weight: 700;
            color: inherit;
            margin-bottom: 12px;
            letter-spacing: .4px;
        }
        
        .section-header p {
            font-size: 15px;
            color: var(--text-secondary);
            max-width: 680px;
        }
        
        .dark-bg .section-header p {
            color: rgba(255,255,255,.6);
        }
        
        .section-tag {
            display: inline-block;
            padding: 5px 14px;
            border-radius: 100px;
            background: rgba(0,194,168,.1);
            color: var(--secondary);
            font-size: 12px;
            font-weight: 600;
            margin-bottom: 12px;
            letter-spacing: 1px;
            text-transform: uppercase;
        }
        
        /* Stats trust bar */
        .stats-bar {
            padding: 0;
            margin-top: -1px;
        }
        
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 0;
            background: #fff;
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-default);
            overflow: hidden;
            border: 1px solid var(--border);
        }
        
        .stat-item {
            padding: 28px 20px;
            text-align: center;
            border-right: 1px solid var(--border);
            transition: var(--transition);
        }
        
        .stat-item:last-child { border-right: none; }
        
        .stat-item:hover { background: rgba(0,194,168,.03); }
        
        .stat-number {
            font-size: 30px;
            font-weight: 700;
            color: var(--primary);
            margin-bottom: 6px;
        }
        
        .stat-number span { color: var(--secondary); }
        
        .stat-label {
            font-size: 13px;
            color: var(--text-secondary);
            font-weight: 500;
        }
        
        /* Features asymmetric */
        .features-grid {
            display: grid;
            grid-template-columns: 1.25fr 1fr;
            gap: 24px;
        }
        
        .feature-card {
            background: var(--card);
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-default);
            border: 1px solid var(--border);
            padding: 32px;
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            gap: 14px;
        }
        
        .feature-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-4px);
            border-color: rgba(0,194,168,.25);
        }
        
        .feature-card.large {
            grid-row: span 2;
        }
        
        .feature-card .feature-icon {
            width: 48px;
            height: 48px;
            border-radius: 12px;
            background: rgba(0,194,168,.1);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 22px;
            color: var(--secondary);
            flex-shrink: 0;
        }
        
        .feature-card h3 {
            font-size: 20px;
            font-weight: 600;
            color: var(--primary);
        }
        
        .feature-card p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        
        .feature-card .feature-img {
            border-radius: 10px;
            overflow: hidden;
            aspect-ratio: 16/9;
            margin-top: auto;
        }
        
        .feature-card .feature-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        
        /* Topic entries */
        .topics-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }
        
        .topic-card {
            position: relative;
            border-radius: var(--radius-card);
            overflow: hidden;
            aspect-ratio: 3/2;
            display: flex;
            align-items: flex-end;
            transition: var(--transition);
            box-shadow: var(--shadow-default);
        }
        
        .topic-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }
        
        .topic-card img {
            position: absolute;
            inset: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        
        .topic-card .topic-overlay {
            position: absolute;
            inset: 0;
            background: linear-gradient(to top, rgba(20,24,40,.85) 0%, rgba(20,24,40,.2) 60%, transparent 100%);
        }
        
        .topic-card .topic-content {
            position: relative;
            z-index: 2;
            padding: 22px 24px;
            color: #fff;
        }
        
        .topic-card .topic-content h3 {
            font-size: 18px;
            font-weight: 600;
            margin-bottom: 4px;
        }
        
        .topic-card .topic-content p {
            font-size: 13px;
            color: rgba(255,255,255,.75);
        }
        
        /* Steps */
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        
        .step-card {
            background: var(--card);
            border-radius: var(--radius-card);
            border: 1px solid var(--border);
            padding: 30px 24px;
            text-align: center;
            transition: var(--transition);
            position: relative;
        }
        
        .step-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-3px);
        }
        
        .step-number {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: var(--secondary);
            color: #fff;
            font-size: 18px;
            font-weight: 700;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 16px;
        }
        
        .step-card h3 {
            font-size: 17px;
            font-weight: 600;
            margin-bottom: 10px;
            color: var(--primary);
        }
        
        .step-card p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        
        /* CMS news list */
        .news-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }
        
        .news-card {
            background: var(--card);
            border-radius: var(--radius-card);
            border: 1px solid var(--border);
            overflow: hidden;
            transition: var(--transition);
            display: flex;
            flex-direction: column;
        }
        
        .news-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-4px);
        }
        
        .news-card .news-img {
            aspect-ratio: 16/9;
            overflow: hidden;
            background: var(--bg);
        }
        
        .news-card .news-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform .3s ease;
        }
        
        .news-card:hover .news-img img {
            transform: scale(1.03);
        }
        
        .news-card .news-body {
            padding: 20px 22px 22px;
            display: flex;
            flex-direction: column;
            gap: 8px;
            flex: 1;
        }
        
        .news-card .news-tag {
            display: inline-flex;
            align-self: flex-start;
            padding: 3px 10px;
            border-radius: 100px;
            background: rgba(0,194,168,.08);
            color: var(--secondary);
            font-size: 12px;
            font-weight: 600;
        }
        
        .news-card .news-title {
            font-size: 16px;
            font-weight: 600;
            color: var(--primary);
            line-height: 1.5;
            margin: 4px 0;
        }
        
        .news-card .news-summary {
            font-size: 13px;
            color: var(--text-secondary);
            line-height: 1.65;
            flex: 1;
        }
        
        .news-card .news-meta {
            font-size: 12px;
            color: #8a90a0;
            display: flex;
            gap: 12px;
            padding-top: 10px;
            border-top: 1px solid var(--border);
            margin-top: auto;
        }
        
        .news-empty {
            text-align: center;
            padding: 48px 20px;
            background: var(--card);
            border-radius: var(--radius-card);
            border: 1px dashed var(--border);
            color: var(--text-secondary);
            font-size: 15px;
            grid-column: 1/-1;
        }
        
        /* Timeline */
        .timeline {
            position: relative;
            padding-left: 28px;
        }
        
        .timeline::before {
            content: '';
            position: absolute;
            left: 8px;
            top: 4px;
            bottom: 4px;
            width: 2px;
            background: rgba(0,194,168,.3);
            border-radius: 2px;
        }
        
        .timeline-item {
            position: relative;
            padding: 0 0 28px 20px;
        }
        
        .timeline-item:last-child { padding-bottom: 0; }
        
        .timeline-item::before {
            content: '';
            position: absolute;
            left: -24px;
            top: 8px;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background: var(--secondary);
            border: 3px solid #fff;
            box-shadow: 0 0 0 3px rgba(0,194,168,.2);
        }
        
        .timeline-item .tl-date {
            font-size: 13px;
            font-weight: 600;
            color: var(--secondary);
            margin-bottom: 4px;
        }
        
        .timeline-item .tl-title {
            font-size: 15px;
            font-weight: 600;
            color: var(--primary);
            margin-bottom: 4px;
        }
        
        .timeline-item .tl-desc {
            font-size: 13px;
            color: var(--text-secondary);
        }
        
        /* Device matrix */
        .device-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 16px;
        }
        
        .device-card {
            background: var(--card);
            border-radius: var(--radius-card);
            border: 1px solid var(--border);
            padding: 24px;
            text-align: center;
            transition: var(--transition);
        }
        
        .device-card:hover {
            box-shadow: var(--shadow-default);
            border-color: rgba(0,194,168,.3);
            transform: translateY(-2px);
        }
        
        .device-card .device-icon {
            font-size: 30px;
            margin-bottom: 10px;
        }
        
        .device-card h4 {
            font-size: 15px;
            font-weight: 600;
            color: var(--primary);
            margin-bottom: 6px;
        }
        
        .device-card p {
            font-size: 13px;
            color: var(--text-secondary);
        }
        
        /* Security section */
        .security-layout {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            align-items: center;
        }
        
        .security-visual {
            border-radius: var(--radius-card);
            overflow: hidden;
            aspect-ratio: 16/10;
            box-shadow: var(--shadow-default);
        }
        
        .security-visual img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        
        .security-list {
            display: flex;
            flex-direction: column;
            gap: 16px;
            margin-top: 20px;
        }
        
        .security-item {
            display: flex;
            gap: 12px;
            align-items: flex-start;
        }
        
        .security-item .check-icon {
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: rgba(0,194,168,.12);
            color: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            flex-shrink: 0;
            font-size: 14px;
        }
        
        .security-item h4 {
            font-size: 15px;
            font-weight: 600;
            color: var(--primary);
            margin-bottom: 2px;
        }
        
        .security-item p {
            font-size: 13px;
            color: var(--text-secondary);
            line-height: 1.6;
        }
        
        /* Testimonials */
        .testimonials-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }
        
        .testimonial-card {
            background: var(--card);
            border-radius: var(--radius-card);
            border: 1px solid var(--border);
            padding: 26px;
            transition: var(--transition);
        }
        
        .testimonial-card:hover {
            box-shadow: var(--shadow-default);
            transform: translateY(-3px);
        }
        
        .testimonial-card .quote-mark {
            font-size: 32px;
            color: var(--secondary);
            line-height: 1;
            margin-bottom: 10px;
            font-weight: 700;
        }
        
        .testimonial-card blockquote {
            font-size: 14px;
            color: var(--text);
            line-height: 1.7;
            font-style: italic;
            margin-bottom: 14px;
        }
        
        .testimonial-card .t-author {
            font-size: 13px;
            font-weight: 600;
            color: var(--primary);
        }
        
        .testimonial-card .t-role {
            font-size: 12px;
            color: var(--text-secondary);
        }
        
        /* Tutorials list */
        .tutorials-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 16px;
        }
        
        .tutorial-card {
            background: var(--card);
            border-radius: var(--radius-card);
            border: 1px solid var(--border);
            padding: 22px;
            transition: var(--transition);
            text-align: left;
        }
        
        .tutorial-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-3px);
            border-color: rgba(0,194,168,.25);
        }
        
        .tutorial-card .tut-num {
            font-size: 12px;
            font-weight: 700;
            color: var(--secondary);
            margin-bottom: 8px;
            letter-spacing: 1px;
        }
        
        .tutorial-card h4 {
            font-size: 15px;
            font-weight: 600;
            color: var(--primary);
            margin-bottom: 6px;
            line-height: 1.45;
        }
        
        .tutorial-card p {
            font-size: 13px;
            color: var(--text-secondary);
            line-height: 1.6;
        }
        
        /* FAQ */
        .faq-layout {
            display: grid;
            grid-template-columns: 320px 1fr;
            gap: 40px;
        }
        
        .faq-left h2 {
            font-size: 26px;
            font-weight: 700;
            color: var(--primary);
            margin-bottom: 12px;
        }
        
        .faq-left p {
            font-size: 14px;
            color: var(--text-secondary);
        }
        
        .faq-list {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        
        .faq-item {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            overflow: hidden;
            transition: var(--transition);
        }
        
        .faq-item:hover {
            border-color: rgba(0,194,168,.25);
        }
        
        .faq-question {
            width: 100%;
            padding: 18px 22px;
            text-align: left;
            font-size: 15px;
            font-weight: 600;
            color: var(--primary);
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            transition: var(--transition);
        }
        
        .faq-question:hover {
            color: var(--secondary);
        }
        
        .faq-question .faq-icon {
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: rgba(0,194,168,.1);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 16px;
            font-weight: 700;
            color: var(--secondary);
            transition: transform .25s ease;
            flex-shrink: 0;
        }
        
        .faq-question.open .faq-icon {
            transform: rotate(45deg);
            background: var(--secondary);
            color: #fff;
        }
        
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height .3s ease, padding .3s ease;
            padding: 0 22px;
        }
        
        .faq-answer.open {
            max-height: 240px;
            padding: 0 22px 18px;
        }
        
        .faq-answer p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        
        /* Resource buttons */
        .resource-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            justify-content: center;
        }
        
        .resource-btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 24px;
            border-radius: var(--radius-btn);
            background: rgba(255,255,255,.08);
            border: 1px solid rgba(255,255,255,.2);
            color: #fff;
            font-size: 14px;
            font-weight: 600;
            transition: var(--transition);
            cursor: pointer;
        }
        
        .resource-btn:hover {
            background: rgba(255,255,255,.15);
            border-color: rgba(255,255,255,.4);
            transform: translateY(-2px);
        }
        
        /* Final CTA */
        .final-cta {
            background: var(--accent);
            border-radius: var(--radius-card);
            padding: 52px 40px;
            text-align: center;
            color: #fff;
        }
        
        .final-cta h2 {
            font-size: 28px;
            font-weight: 700;
            margin-bottom: 12px;
        }
        
        .final-cta p {
            font-size: 15px;
            color: rgba(255,255,255,.85);
            max-width: 560px;
            margin: 0 auto 28px;
        }
        
        .final-cta .btn {
            background: #fff;
            color: var(--accent);
        }
        
        .final-cta .btn:hover {
            background: #f0f0f0;
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(0,0,0,.2);
        }
        
        /* Footer */
        .site-footer {
            background: var(--primary);
            color: rgba(255,255,255,.7);
            padding: 56px 0 0;
            font-size: 14px;
        }
        
        .footer-grid {
            display: grid;
            grid-template-columns: 1.5fr 1fr 1fr 1fr;
            gap: 40px;
            padding-bottom: 40px;
        }
        
        .footer-brand .logo {
            color: #fff;
            margin-bottom: 14px;
        }
        
        .footer-brand p {
            font-size: 13px;
            line-height: 1.7;
            max-width: 300px;
            color: rgba(255,255,255,.55);
        }
        
        .footer-col h4 {
            font-size: 14px;
            font-weight: 600;
            color: #fff;
            margin-bottom: 14px;
            letter-spacing: .5px;
        }
        
        .footer-col a {
            display: block;
            padding: 5px 0;
            color: rgba(255,255,255,.55);
            font-size: 13px;
            transition: var(--transition);
        }
        
        .footer-col a:hover {
            color: var(--secondary);
            transform: translateX(3px);
        }
        
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,.1);
            padding: 18px 0;
            text-align: center;
            font-size: 12px;
            color: rgba(255,255,255,.4);
        }
        
        /* Mobile menu */
        @media (max-width: 1024px) {
            .features-grid {
                grid-template-columns: 1fr;
            }
            .feature-card.large {
                grid-row: auto;
            }
            .tutorials-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 30px;
            }
        }
        
        @media (max-width: 768px) {
            :root {
                --nav-height: 62px;
            }
            .main-nav {
                display: none;
            }
            .hamburger {
                display: flex;
            }
            .mobile-overlay {
                display: block;
            }
            .hero {
                padding: 48px 0 56px;
            }
            .hero .container {
                grid-template-columns: 1fr;
                gap: 32px;
            }
            .hero-content h1 {
                font-size: 28px;
            }
            .hero-content .hero-sub {
                font-size: 15px;
            }
            .hero-visual {
                aspect-ratio: 16/9;
            }
            section {
                padding: 48px 0;
            }
            .section-header h2 {
                font-size: 22px;
            }
            .stats-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .stat-item:nth-child(2) {
                border-right: none;
            }
            .stat-item:nth-child(1),
            .stat-item:nth-child(2) {
                border-bottom: 1px solid var(--border);
            }
            .topics-grid {
                grid-template-columns: 1fr;
            }
            .steps-grid {
                grid-template-columns: 1fr;
                gap: 16px;
            }
            .news-grid {
                grid-template-columns: 1fr;
            }
            .device-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 12px;
            }
            .security-layout {
                grid-template-columns: 1fr;
                gap: 24px;
            }
            .testimonials-grid {
                grid-template-columns: 1fr;
            }
            .tutorials-grid {
                grid-template-columns: 1fr;
            }
            .faq-layout {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .final-cta {
                padding: 36px 24px;
            }
            .final-cta h2 {
                font-size: 22px;
            }
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 28px;
            }
            .container {
                padding: 0 18px;
            }
        }
        
        @media (max-width: 520px) {
            .device-grid {
                grid-template-columns: 1fr;
            }
            .btn {
                width: 100%;
                justify-content: center;
            }
            .hero-cta {
                flex-direction: column;
            }
            .resource-buttons {
                flex-direction: column;
            }
            .resource-btn {
                width: 100%;
                justify-content: center;
            }
        }

/* roulang page: article */
:root {
            --primary: #141827;
            --secondary: #00C2A8;
            --accent: #FF5A3C;
            --bg: #F4F7FA;
            --card: #FFFFFF;
            --text: #1A1D29;
            --text-secondary: #5B6270;
            --border: #E6E9F0;
            --radius-card: 14px;
            --radius-btn: 10px;
            --shadow-default: 0 6px 24px rgba(20,24,40,.05);
            --shadow-hover: 0 12px 32px rgba(20,24,40,.12);
            --font-stack: 'PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,-apple-system,BlinkMacSystemFont,sans-serif;
            --transition: all .22s ease;
            --max-width: 1200px;
            --nav-height: 72px;
        }
        html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
        body {
            font-family: var(--font-stack);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        img { max-width: 100%; height: auto; display: block; }
        a { text-decoration: none; color: inherit; transition: var(--transition); }
        button { font-family: inherit; cursor: pointer; border: none; background: none; }
        input,textarea,select { font-family: inherit; font-size: 16px; }
        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        /* Header / Navigation */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            height: var(--nav-height);
            background: rgba(255,255,255,.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            transition: var(--transition);
        }
        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 18px;
            color: var(--primary);
            letter-spacing: .3px;
            flex-shrink: 0;
        }
        .logo-icon {
            width: 38px;
            height: 38px;
            border-radius: 9px;
            background: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
            font-weight: 800;
            flex-shrink: 0;
        }
        .logo span { white-space: nowrap; }
        .main-nav {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .main-nav a {
            display: inline-flex;
            align-items: center;
            padding: 8px 16px;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            position: relative;
            transition: var(--transition);
            white-space: nowrap;
        }
        .main-nav a:hover {
            color: var(--secondary);
            background: rgba(0,194,168,.06);
        }
        .main-nav a.active {
            color: var(--accent);
            font-weight: 600;
        }
        .main-nav a.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 16px;
            right: 16px;
            height: 3px;
            border-radius: 2px;
            background: var(--accent);
        }
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            padding: 8px;
            border-radius: 8px;
            transition: var(--transition);
            z-index: 1100;
        }
        .hamburger span {
            display: block;
            width: 24px;
            height: 2.5px;
            background: var(--primary);
            border-radius: 2px;
            transition: var(--transition);
        }
        .hamburger.open span:nth-child(1) {
            transform: translateY(7.5px) rotate(45deg);
        }
        .hamburger.open span:nth-child(2) {
            opacity: 0;
        }
        .hamburger.open span:nth-child(3) {
            transform: translateY(-7.5px) rotate(-45deg);
        }
        .mobile-overlay {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(20,24,40,.55);
            z-index: 1050;
            opacity: 0;
            transition: opacity .25s ease;
        }
        .mobile-overlay.show {
            opacity: 1;
        }
        .mobile-drawer {
            position: fixed;
            top: 0;
            right: -320px;
            width: 300px;
            max-width: 85vw;
            height: 100vh;
            background: #fff;
            z-index: 1060;
            padding: 80px 24px 40px;
            display: flex;
            flex-direction: column;
            transition: right .3s ease;
            box-shadow: -8px 0 40px rgba(20,24,40,.1);
        }
        .mobile-drawer.open {
            right: 0;
        }
        .mobile-drawer a {
            display: block;
            padding: 14px 16px;
            font-size: 16px;
            font-weight: 500;
            color: var(--text);
            border-radius: 10px;
            transition: var(--transition);
        }
        .mobile-drawer a:hover {
            background: var(--bg);
            color: var(--secondary);
        }
        .mobile-drawer a.active {
            color: var(--accent);
            font-weight: 600;
            background: rgba(255,90,60,.06);
        }
        /* Article Page Header */
        .article-page-header {
            background: #fff;
            border-bottom: 1px solid var(--border);
            padding: 18px 0;
        }
        .breadcrumb-article {
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 8px;
            font-size: 13px;
            color: var(--text-secondary);
            margin: 0;
            padding: 0;
            list-style: none;
        }
        .breadcrumb-article li {
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .breadcrumb-article li:not(:last-child)::after {
            content: '/';
            color: #B8BFCB;
            font-size: 12px;
        }
        .breadcrumb-article a {
            color: var(--text-secondary);
            transition: var(--transition);
        }
        .breadcrumb-article a:hover {
            color: var(--secondary);
        }
        .breadcrumb-article .current {
            color: var(--text);
            font-weight: 500;
            max-width: 320px;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }
        /* Article Main Area */
        .article-main {
            padding: 48px 0 64px;
        }
        .article-layout {
            max-width: 820px;
            margin: 0 auto;
        }
        /* Article Header */
        .article-head {
            margin-bottom: 32px;
            text-align: left;
        }
        .article-head h1 {
            font-size: 34px;
            font-weight: 700;
            line-height: 1.35;
            color: var(--text);
            margin: 0 0 16px;
        }
        .article-meta {
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 12px;
            font-size: 14px;
            color: var(--text-secondary);
            padding-bottom: 20px;
            border-bottom: 1px solid var(--border);
        }
        .article-meta .meta-item {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            white-space: nowrap;
        }
        .article-meta .meta-divider {
            width: 1px;
            height: 16px;
            background: var(--border);
        }
        .article-meta .meta-tag {
            display: inline-flex;
            align-items: center;
            padding: 4px 10px;
            border-radius: 6px;
            background: rgba(0,194,168,.08);
            color: var(--secondary);
            font-size: 13px;
            font-weight: 500;
        }
        .article-meta .meta-views {
            color: #B8BFCB;
            font-size: 13px;
        }
        /* Article Body */
        .article-body {
            font-size: 16px;
            line-height: 1.85;
            color: var(--text);
        }
        .article-body h2 {
            font-size: 22px;
            font-weight: 700;
            color: var(--text);
            margin: 32px 0 16px;
            padding-left: 14px;
            border-left: 4px solid var(--secondary);
        }
        .article-body h3 {
            font-size: 19px;
            font-weight: 600;
            color: var(--text);
            margin: 24px 0 12px;
        }
        .article-body p {
            margin: 0 0 16px;
        }
        .article-body img {
            border-radius: var(--radius-card);
            margin: 20px 0;
            box-shadow: var(--shadow-default);
        }
        .article-body blockquote {
            margin: 20px 0;
            padding: 18px 22px;
            background: rgba(0,194,168,.05);
            border-left: 4px solid var(--secondary);
            border-radius: 8px;
            color: var(--text-secondary);
            font-style: italic;
        }
        .article-body ul,
        .article-body ol {
            margin: 0 0 16px;
            padding-left: 24px;
        }
        .article-body ul li,
        .article-body ol li {
            margin-bottom: 8px;
        }
        .article-body .step-list {
            list-style: none;
            padding: 0;
            margin: 20px 0;
        }
        .article-body .step-list li {
            display: flex;
            gap: 14px;
            align-items: flex-start;
            margin-bottom: 12px;
            padding: 14px 18px;
            background: var(--bg);
            border-radius: 10px;
            border: 1px solid var(--border);
        }
        .article-body .step-list .step-num {
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: var(--secondary);
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 14px;
            font-weight: 700;
            flex-shrink: 0;
        }
        /* Article CTA */
        .article-cta {
            margin: 36px 0;
            padding: 24px 28px;
            background: var(--primary);
            border-radius: var(--radius-card);
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 20px;
            flex-wrap: wrap;
        }
        .article-cta-text h3 {
            font-size: 18px;
            font-weight: 700;
            margin: 0 0 6px;
            color: #fff;
        }
        .article-cta-text p {
            font-size: 14px;
            color: rgba(255,255,255,.75);
            margin: 0;
        }
        .article-cta .btn-cta {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 22px;
            border-radius: var(--radius-btn);
            background: var(--accent);
            color: #fff;
            font-weight: 600;
            font-size: 14px;
            transition: var(--transition);
            white-space: nowrap;
        }
        .article-cta .btn-cta:hover {
            background: #e04a2f;
            transform: translateY(-1px);
            box-shadow: 0 8px 20px rgba(255,90,60,.35);
            color: #fff;
        }
        /* Recommended */
        .recommended-section {
            margin-top: 48px;
            padding-top: 32px;
            border-top: 1px solid var(--border);
        }
        .recommended-section .section-label {
            font-size: 14px;
            font-weight: 600;
            color: var(--text-secondary);
            letter-spacing: 1px;
            margin-bottom: 16px;
        }
        .recommended-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 16px;
        }
        .rec-card {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            padding: 18px;
            transition: var(--transition);
            display: block;
        }
        .rec-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: rgba(0,194,168,.35);
            color: inherit;
        }
        .rec-card h4 {
            font-size: 15px;
            font-weight: 600;
            color: var(--text);
            margin: 0 0 8px;
            line-height: 1.5;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .rec-card .rec-meta {
            font-size: 13px;
            color: var(--text-secondary);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .rec-card .rec-meta .rec-cat {
            padding: 2px 8px;
            border-radius: 4px;
            background: rgba(0,194,168,.08);
            color: var(--secondary);
            font-size: 12px;
            font-weight: 500;
        }
        /* Prev Next Nav */
        .prev-next-nav {
            margin-top: 36px;
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 16px;
        }
        .pn-card {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            padding: 16px 20px;
            transition: var(--transition);
            display: block;
        }
        .pn-card:hover {
            border-color: rgba(0,194,168,.35);
            box-shadow: var(--shadow-default);
            color: inherit;
        }
        .pn-card .pn-label {
            font-size: 12px;
            color: #B8BFCB;
            letter-spacing: 1px;
            margin-bottom: 6px;
            text-transform: uppercase;
        }
        .pn-card .pn-title {
            font-size: 14px;
            font-weight: 600;
            color: var(--text);
            margin: 0;
            line-height: 1.5;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .pn-card.next {
            text-align: right;
        }
        /* Tags / Resources */
        .article-tags {
            margin-top: 32px;
            padding: 20px 24px;
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
        }
        .article-tags .tags-label {
            font-size: 14px;
            font-weight: 600;
            color: var(--text-secondary);
            margin-bottom: 10px;
        }
        .article-tags .tags-row {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
        }
        .article-tags .tag-chip {
            padding: 6px 14px;
            border-radius: 20px;
            background: var(--bg);
            border: 1px solid var(--border);
            font-size: 13px;
            color: var(--text-secondary);
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
        }
        .article-tags .tag-chip:hover {
            background: rgba(0,194,168,.08);
            border-color: rgba(0,194,168,.35);
            color: var(--secondary);
        }
        /* Back Entry */
        .back-entry {
            margin-top: 32px;
            text-align: center;
        }
        .back-entry .btn-back {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 24px;
            border-radius: var(--radius-btn);
            background: var(--card);
            border: 1px solid var(--border);
            color: var(--text);
            font-weight: 600;
            font-size: 14px;
            transition: var(--transition);
        }
        .back-entry .btn-back:hover {
            background: var(--bg);
            border-color: rgba(0,194,168,.35);
            color: var(--secondary);
            transform: translateY(-1px);
        }
        /* Not Found */
        .article-not-found {
            text-align: center;
            padding: 80px 20px;
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
        }
        .article-not-found .nf-icon {
            font-size: 48px;
            margin-bottom: 16px;
        }
        .article-not-found h2 {
            font-size: 22px;
            font-weight: 700;
            margin: 0 0 8px;
        }
        .article-not-found p {
            color: var(--text-secondary);
            margin: 0 0 20px;
        }
        .article-not-found .btn-home {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 10px 20px;
            border-radius: var(--radius-btn);
            background: var(--secondary);
            color: #fff;
            font-weight: 600;
            font-size: 14px;
            transition: var(--transition);
        }
        .article-not-found .btn-home:hover {
            background: #00a690;
            color: #fff;
            transform: translateY(-1px);
        }
        /* Empty state for recommended */
        .rec-empty {
            grid-column: 1 / -1;
            padding: 32px;
            text-align: center;
            background: var(--card);
            border: 1px dashed var(--border);
            border-radius: var(--radius-card);
            color: var(--text-secondary);
            font-size: 14px;
        }
        /* Footer */
        .site-footer {
            background: var(--primary);
            color: rgba(255,255,255,.85);
            padding: 56px 0 28px;
            margin-top: 32px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 32px;
            padding-bottom: 32px;
            border-bottom: 1px solid rgba(255,255,255,.1);
        }
        .footer-brand .logo {
            color: #fff;
            margin-bottom: 12px;
        }
        .footer-brand p {
            font-size: 14px;
            color: rgba(255,255,255,.7);
            line-height: 1.7;
            margin: 0;
            max-width: 320px;
        }
        .footer-col h4 {
            font-size: 14px;
            font-weight: 700;
            color: #fff;
            margin: 0 0 14px;
        }
        .footer-col a {
            display: block;
            font-size: 14px;
            color: rgba(255,255,255,.7);
            padding: 6px 0;
            transition: var(--transition);
        }
        .footer-col a:hover {
            color: var(--secondary);
        }
        .footer-bottom {
            padding-top: 20px;
            text-align: center;
            font-size: 13px;
            color: rgba(255,255,255,.55);
        }
        .footer-bottom p {
            margin: 0;
        }
        /* Responsive */
        @media (max-width: 1024px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 24px;
            }
            .article-head h1 {
                font-size: 28px;
            }
        }
        @media (max-width: 768px) {
            :root {
                --nav-height: 62px;
            }
            .main-nav {
                display: none;
            }
            .hamburger {
                display: flex;
            }
            .mobile-overlay {
                display: block;
                pointer-events: none;
            }
            .mobile-overlay.show {
                pointer-events: auto;
            }
            .container {
                padding: 0 20px;
            }
            .article-main {
                padding: 32px 0 48px;
            }
            .article-head h1 {
                font-size: 24px;
            }
            .article-body {
                font-size: 15px;
                line-height: 1.75;
            }
            .article-body h2 {
                font-size: 19px;
                margin: 24px 0 12px;
            }
            .article-body h3 {
                font-size: 17px;
                margin: 20px 0 10px;
            }
            .article-cta {
                flex-direction: column;
                align-items: flex-start;
                padding: 20px;
            }
            .recommended-grid {
                grid-template-columns: 1fr;
            }
            .prev-next-nav {
                grid-template-columns: 1fr;
            }
            .pn-card.next {
                text-align: left;
            }
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .article-meta {
                gap: 8px;
            }
            .article-meta .meta-divider {
                display: none;
            }
        }
        @media (max-width: 520px) {
            .article-head h1 {
                font-size: 21px;
            }
            .article-body {
                font-size: 14px;
                line-height: 1.7;
            }
            .article-cta-text h3 {
                font-size: 16px;
            }
            .breadcrumb-article .current {
                max-width: 160px;
            }
        }

/* roulang page: category1 */
:root {
            --primary: #141827;
            --secondary: #00C2A8;
            --accent: #FF5A3C;
            --bg: #F4F7FA;
            --card: #FFFFFF;
            --text: #1A1D29;
            --text-secondary: #5B6270;
            --border: #E6E9F0;
            --radius-card: 14px;
            --radius-btn: 10px;
            --shadow-default: 0 6px 24px rgba(20,24,40,.05);
            --shadow-hover: 0 12px 32px rgba(20,24,40,.12);
            --font-stack: 'PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,-apple-system,BlinkMacSystemFont,sans-serif;
            --transition: all .22s ease;
            --max-width: 1200px;
            --nav-height: 72px;
        }
        html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
        body {
            font-family: var(--font-stack);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        img { max-width: 100%; height: auto; display: block; }
        a { text-decoration: none; color: inherit; transition: var(--transition); }
        button { font-family: inherit; cursor: pointer; border: none; background: none; }
        input,textarea,select { font-family: inherit; font-size: 16px; }
        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        /* Header / Navigation */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            height: var(--nav-height);
            background: rgba(255,255,255,.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            transition: var(--transition);
        }
        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 18px;
            color: var(--primary);
            letter-spacing: .3px;
            flex-shrink: 0;
        }
        .logo-icon {
            width: 38px;
            height: 38px;
            border-radius: 9px;
            background: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
            font-weight: 800;
            flex-shrink: 0;
        }
        .logo span { white-space: nowrap; }
        .main-nav {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .main-nav a {
            display: inline-flex;
            align-items: center;
            padding: 8px 16px;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            position: relative;
            transition: var(--transition);
            white-space: nowrap;
        }
        .main-nav a:hover {
            color: var(--secondary);
            background: rgba(0,194,168,.06);
        }
        .main-nav a.active {
            color: var(--accent);
            font-weight: 600;
        }
        .main-nav a.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 16px;
            right: 16px;
            height: 3px;
            border-radius: 2px;
            background: var(--accent);
        }
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            padding: 8px;
            border-radius: 8px;
            transition: var(--transition);
            z-index: 1100;
        }
        .hamburger span {
            display: block;
            width: 24px;
            height: 2.5px;
            background: var(--primary);
            border-radius: 2px;
            transition: var(--transition);
        }
        .hamburger.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
        .hamburger.open span:nth-child(2) { opacity: 0; }
        .hamburger.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }
        .mobile-overlay {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(20,24,40,.55);
            z-index: 1050;
            opacity: 0;
            transition: opacity .25s ease;
        }
        .mobile-overlay.show { opacity: 1; }
        .mobile-drawer {
            position: fixed;
            top: 0;
            right: -320px;
            width: 300px;
            max-width: 85vw;
            height: 100vh;
            background: #fff;
            z-index: 1060;
            padding: 80px 24px 40px;
            display: flex;
            flex-direction: column;
            transition: right .3s ease;
            box-shadow: -8px 0 40px rgba(20,24,40,.1);
        }
        .mobile-drawer.open { right: 0; }
        .mobile-drawer a {
            display: block;
            padding: 14px 16px;
            font-size: 16px;
            font-weight: 500;
            color: var(--text);
            border-radius: 10px;
            transition: var(--transition);
        }
        .mobile-drawer a:hover { background: var(--bg); color: var(--secondary); }
        .mobile-drawer a.active {
            color: var(--accent);
            font-weight: 600;
            background: rgba(255,90,60,.06);
        }
        /* Category Page Header */
        .category-header {
            background: #fff;
            border-bottom: 1px solid var(--border);
            padding: 40px 0 36px;
            position: relative;
            overflow: hidden;
        }
        .category-header::before {
            content: '';
            position: absolute;
            top: -80px;
            right: -60px;
            width: 320px;
            height: 320px;
            border-radius: 50%;
            background: rgba(0,194,168,.06);
            pointer-events: none;
        }
        .breadcrumb-custom {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 13px;
            color: var(--text-secondary);
            margin-bottom: 16px;
            flex-wrap: wrap;
        }
        .breadcrumb-custom a { color: var(--text-secondary); }
        .breadcrumb-custom a:hover { color: var(--secondary); }
        .breadcrumb-custom .sep { color: #c0c6d1; }
        .breadcrumb-custom .current { color: var(--text); font-weight: 500; }
        .category-header h1 {
            font-size: 32px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 12px;
            letter-spacing: .5px;
            line-height: 1.35;
        }
        .category-header .lead {
            font-size: 16px;
            color: var(--text-secondary);
            max-width: 720px;
            margin: 0 0 20px;
            line-height: 1.8;
        }
        .header-stats {
            display: flex;
            gap: 32px;
            flex-wrap: wrap;
            padding-top: 8px;
        }
        .header-stat {
            display: flex;
            flex-direction: column;
            gap: 2px;
        }
        .header-stat .stat-num {
            font-size: 22px;
            font-weight: 700;
            color: var(--primary);
            line-height: 1.3;
        }
        .header-stat .stat-label {
            font-size: 13px;
            color: var(--text-secondary);
        }
        /* Filter Bar */
        .filter-section {
            background: var(--bg);
            padding: 28px 0 8px;
        }
        .filter-bar {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-wrap: wrap;
            background: #fff;
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            padding: 16px 20px;
            box-shadow: var(--shadow-default);
        }
        .filter-label {
            font-size: 14px;
            font-weight: 600;
            color: var(--text);
            margin-right: 6px;
            white-space: nowrap;
        }
        .filter-chip {
            display: inline-flex;
            align-items: center;
            padding: 7px 16px;
            border-radius: 20px;
            font-size: 13px;
            font-weight: 500;
            color: var(--text-secondary);
            background: var(--bg);
            border: 1px solid transparent;
            transition: var(--transition);
            white-space: nowrap;
            cursor: pointer;
        }
        .filter-chip:hover {
            color: var(--secondary);
            border-color: var(--secondary);
            background: rgba(0,194,168,.05);
        }
        .filter-chip.active {
            background: var(--secondary);
            color: #fff;
            border-color: var(--secondary);
            font-weight: 600;
        }
        .filter-note {
            font-size: 13px;
            color: var(--text-secondary);
            margin-left: auto;
            white-space: nowrap;
        }
        /* Version Cards Grid */
        .version-section {
            padding: 36px 0 64px;
            background: var(--bg);
        }
        .section-heading {
            margin-bottom: 28px;
        }
        .section-heading h2 {
            font-size: 26px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 8px;
            letter-spacing: .3px;
        }
        .section-heading p {
            font-size: 15px;
            color: var(--text-secondary);
            margin: 0;
        }
        .version-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .version-card {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            overflow: hidden;
            box-shadow: var(--shadow-default);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
        }
        .version-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-4px);
            border-color: rgba(0,194,168,.3);
        }
        .version-card-img {
            width: 100%;
            aspect-ratio: 16/9;
            overflow: hidden;
            background: #f0f2f6;
            position: relative;
        }
        .version-card-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }
        .version-card:hover .version-card-img img { transform: scale(1.04); }
        .version-badge {
            position: absolute;
            top: 12px;
            left: 12px;
            padding: 5px 12px;
            border-radius: 6px;
            font-size: 12px;
            font-weight: 600;
            color: #fff;
            background: var(--secondary);
            letter-spacing: .3px;
        }
        .version-badge.beta { background: #FF9F2E; }
        .version-badge.patch { background: #6C7AEA; }
        .version-badge.history { background: #8A94A6; }
        .version-card-body {
            padding: 20px 20px 22px;
            flex: 1;
            display: flex;
            flex-direction: column;
        }
        .version-card-meta {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 13px;
            color: var(--text-secondary);
            margin-bottom: 10px;
        }
        .version-card-meta .ver {
            font-weight: 700;
            color: var(--primary);
            font-size: 15px;
        }
        .version-card-meta .dot {
            width: 3px;
            height: 3px;
            border-radius: 50%;
            background: #c0c6d1;
        }
        .version-card-title {
            font-size: 17px;
            font-weight: 600;
            color: var(--text);
            margin: 0 0 8px;
            line-height: 1.5;
        }
        .version-card-desc {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
            margin: 0 0 16px;
            flex: 1;
        }
        .version-card-link {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            font-size: 14px;
            font-weight: 600;
            color: var(--secondary);
            transition: var(--transition);
            align-self: flex-start;
        }
        .version-card-link:hover { color: #00a98f; gap: 10px; }
        .version-card-link .arrow { transition: var(--transition); }
        /* Related Topics */
        .related-topics {
            padding: 56px 0 64px;
            background: #fff;
            border-top: 1px solid var(--border);
            border-bottom: 1px solid var(--border);
        }
        .topic-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }
        .topic-card {
            background: var(--bg);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            padding: 22px 20px;
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        .topic-card:hover {
            background: #fff;
            box-shadow: var(--shadow-hover);
            border-color: rgba(0,194,168,.3);
            transform: translateY(-3px);
        }
        .topic-card .topic-icon {
            width: 40px;
            height: 40px;
            border-radius: 8px;
            background: rgba(0,194,168,.1);
            color: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 18px;
            font-weight: 700;
        }
        .topic-card h3 {
            font-size: 16px;
            font-weight: 600;
            color: var(--text);
            margin: 0;
            line-height: 1.4;
        }
        .topic-card p {
            font-size: 13px;
            color: var(--text-secondary);
            margin: 0;
            line-height: 1.6;
            flex: 1;
        }
        .topic-card a {
            font-size: 13px;
            font-weight: 600;
            color: var(--secondary);
            display: inline-flex;
            align-items: center;
            gap: 4px;
        }
        .topic-card a:hover { color: #00a98f; }
        /* Install Tips */
        .install-tips {
            padding: 56px 0 64px;
            background: var(--bg);
        }
        .install-tip-banner {
            background: var(--primary);
            border-radius: var(--radius-card);
            padding: 36px 40px;
            display: flex;
            align-items: center;
            gap: 32px;
            position: relative;
            overflow: hidden;
        }
        .install-tip-banner::after {
            content: '';
            position: absolute;
            right: -40px;
            bottom: -80px;
            width: 260px;
            height: 260px;
            border-radius: 50%;
            background: rgba(0,194,168,.08);
            pointer-events: none;
        }
        .install-tip-content {
            flex: 1;
            z-index: 1;
        }
        .install-tip-content h2 {
            font-size: 22px;
            font-weight: 700;
            color: #fff;
            margin: 0 0 10px;
        }
        .install-tip-content p {
            font-size: 15px;
            color: rgba(255,255,255,.75);
            margin: 0;
            line-height: 1.7;
        }
        .install-tip-actions {
            display: flex;
            gap: 12px;
            z-index: 1;
            flex-shrink: 0;
        }
        .btn-outline-light {
            display: inline-flex;
            align-items: center;
            padding: 11px 22px;
            border-radius: var(--radius-btn);
            font-size: 14px;
            font-weight: 600;
            color: #fff;
            border: 1.5px solid rgba(255,255,255,.4);
            transition: var(--transition);
            white-space: nowrap;
        }
        .btn-outline-light:hover {
            border-color: var(--secondary);
            background: var(--secondary);
            color: #fff;
            transform: translateY(-1px);
        }
        .btn-accent-solid {
            display: inline-flex;
            align-items: center;
            padding: 11px 22px;
            border-radius: var(--radius-btn);
            font-size: 14px;
            font-weight: 600;
            color: #fff;
            background: var(--accent);
            transition: var(--transition);
            white-space: nowrap;
        }
        .btn-accent-solid:hover {
            background: #e94b2f;
            transform: translateY(-1px);
            box-shadow: 0 8px 20px rgba(255,90,60,.35);
        }
        /* Download CTA */
        .download-cta {
            padding: 56px 0 64px;
            background: #fff;
            border-top: 1px solid var(--border);
        }
        .cta-wrapper {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-default);
            padding: 36px 40px;
            display: flex;
            align-items: center;
            gap: 28px;
            flex-wrap: wrap;
        }
        .cta-icon {
            width: 64px;
            height: 64px;
            border-radius: 14px;
            background: rgba(0,194,168,.1);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 30px;
            flex-shrink: 0;
        }
        .cta-content { flex: 1; min-width: 240px; }
        .cta-content h2 {
            font-size: 22px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 8px;
        }
        .cta-content p {
            font-size: 15px;
            color: var(--text-secondary);
            margin: 0;
            line-height: 1.7;
        }
        .btn-download-primary {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 13px 28px;
            border-radius: var(--radius-btn);
            font-size: 15px;
            font-weight: 700;
            color: #fff;
            background: var(--accent);
            transition: var(--transition);
            white-space: nowrap;
        }
        .btn-download-primary:hover {
            background: #e94b2f;
            transform: translateY(-2px);
            box-shadow: 0 10px 24px rgba(255,90,60,.35);
        }
        .btn-download-primary:focus {
            outline: 3px solid rgba(255,90,60,.35);
            outline-offset: 2px;
        }
        .btn-download-primary:active { transform: translateY(0); }
        /* FAQ */
        .faq-section {
            padding: 56px 0 64px;
            background: var(--bg);
        }
        .faq-grid {
            display: grid;
            grid-template-columns: 1fr 2fr;
            gap: 40px;
            align-items: start;
        }
        .faq-left h2 {
            font-size: 26px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 10px;
        }
        .faq-left p {
            font-size: 15px;
            color: var(--text-secondary);
            margin: 0;
            line-height: 1.7;
        }
        .accordion-custom { display: flex; flex-direction: column; gap: 12px; }
        .accordion-item-custom {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            overflow: hidden;
            transition: var(--transition);
        }
        .accordion-item-custom:hover { border-color: rgba(0,194,168,.3); }
        .accordion-toggle {
            width: 100%;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 18px 22px;
            background: none;
            font-size: 16px;
            font-weight: 600;
            color: var(--text);
            text-align: left;
            transition: var(--transition);
            cursor: pointer;
        }
        .accordion-toggle .icon {
            font-size: 18px;
            color: var(--text-secondary);
            transition: var(--transition);
            flex-shrink: 0;
            margin-left: 12px;
        }
        .accordion-item-custom.open .accordion-toggle .icon { transform: rotate(45deg); color: var(--secondary); }
        .accordion-body {
            max-height: 0;
            overflow: hidden;
            transition: max-height .3s ease, padding .3s ease;
            padding: 0 22px;
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.8;
        }
        .accordion-item-custom.open .accordion-body {
            max-height: 300px;
            padding: 0 22px 20px;
        }
        /* Back Home CTA */
        .back-home-section {
            padding: 48px 0 64px;
            background: var(--primary);
            position: relative;
            overflow: hidden;
        }
        .back-home-section::before {
            content: '';
            position: absolute;
            inset: 0;
            background-image: 
                linear-gradient(rgba(255,255,255,.03) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255,255,255,.03) 1px, transparent 1px);
            background-size: 48px 48px;
            pointer-events: none;
        }
        .back-home-content {
            text-align: center;
            position: relative;
            z-index: 1;
            max-width: 620px;
            margin: 0 auto;
        }
        .back-home-content h2 {
            font-size: 28px;
            font-weight: 700;
            color: #fff;
            margin: 0 0 14px;
            line-height: 1.4;
        }
        .back-home-content p {
            font-size: 16px;
            color: rgba(255,255,255,.75);
            margin: 0 0 28px;
            line-height: 1.7;
        }
        .btn-home-return {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 13px 30px;
            border-radius: var(--radius-btn);
            font-size: 15px;
            font-weight: 600;
            color: #fff;
            background: var(--secondary);
            transition: var(--transition);
        }
        .btn-home-return:hover {
            background: #00a98f;
            transform: translateY(-2px);
            box-shadow: 0 10px 24px rgba(0,194,168,.35);
        }
        /* Footer */
        .site-footer {
            background: var(--primary);
            color: rgba(255,255,255,.75);
            padding: 56px 0 32px;
            font-size: 14px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }
        .footer-brand .logo {
            color: #fff;
            margin-bottom: 16px;
        }
        .footer-brand p {
            font-size: 14px;
            color: rgba(255,255,255,.65);
            line-height: 1.7;
            margin: 0;
            max-width: 320px;
        }
        .footer-col h4 {
            font-size: 15px;
            font-weight: 600;
            color: #fff;
            margin: 0 0 16px;
        }
        .footer-col a {
            display: block;
            font-size: 14px;
            color: rgba(255,255,255,.65);
            padding: 5px 0;
            transition: var(--transition);
        }
        .footer-col a:hover { color: var(--secondary); padding-left: 4px; }
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,.1);
            padding-top: 24px;
            text-align: center;
            font-size: 13px;
            color: rgba(255,255,255,.5);
        }
        .footer-bottom p { margin: 0; }
        /* Responsive */
        @media (max-width: 1024px) {
            .version-grid { grid-template-columns: repeat(2, 1fr); }
            .topic-grid { grid-template-columns: repeat(2, 1fr); }
            .faq-grid { grid-template-columns: 1fr; gap: 24px; }
            .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
        }
        @media (max-width: 768px) {
            :root { --nav-height: 62px; }
            .container { padding: 0 20px; }
            .main-nav { display: none; }
            .hamburger { display: flex; }
            .mobile-overlay { display: block; pointer-events: none; }
            .mobile-overlay.show { pointer-events: auto; }
            .category-header { padding: 28px 0 28px; }
            .category-header h1 { font-size: 24px; }
            .category-header .lead { font-size: 15px; }
            .header-stats { gap: 20px; }
            .header-stat .stat-num { font-size: 18px; }
            .version-grid { grid-template-columns: 1fr; }
            .topic-grid { grid-template-columns: 1fr; }
            .install-tip-banner { flex-direction: column; align-items: flex-start; padding: 28px 24px; }
            .install-tip-actions { flex-wrap: wrap; }
            .cta-wrapper { flex-direction: column; align-items: flex-start; padding: 28px 24px; }
            .footer-grid { grid-template-columns: 1fr; gap: 24px; }
            .filter-bar { padding: 14px 16px; }
            .filter-note { margin-left: 0; width: 100%; }
        }
        @media (max-width: 520px) {
            .category-header h1 { font-size: 21px; }
            .version-card-body { padding: 16px; }
            .install-tip-banner { padding: 22px 18px; }
            .cta-wrapper { padding: 22px 18px; }
            .btn-download-primary { width: 100%; justify-content: center; }
            .back-home-content h2 { font-size: 22px; }
        }

/* roulang page: category3 */
:root {
            --primary: #141827;
            --secondary: #00C2A8;
            --accent: #FF5A3C;
            --bg: #F4F7FA;
            --card: #FFFFFF;
            --text: #1A1D29;
            --text-secondary: #5B6270;
            --border: #E6E9F0;
            --radius-card: 14px;
            --radius-btn: 10px;
            --shadow-default: 0 6px 24px rgba(20,24,40,.05);
            --shadow-hover: 0 12px 32px rgba(20,24,40,.12);
            --font-stack: 'PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,-apple-system,BlinkMacSystemFont,sans-serif;
            --transition: all .22s ease;
            --max-width: 1200px;
            --nav-height: 72px;
        }
        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }
        body {
            font-family: var(--font-stack);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            margin: 0;
        }
        *, *::before, *::after {
            box-sizing: border-box;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }
        button {
            font-family: inherit;
            cursor: pointer;
            border: none;
            background: none;
        }
        input, textarea, select {
            font-family: inherit;
            font-size: 16px;
        }
        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        /* Header / Navigation */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            height: var(--nav-height);
            background: rgba(255,255,255,.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            transition: var(--transition);
        }
        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 18px;
            color: var(--primary);
            letter-spacing: .3px;
            flex-shrink: 0;
        }
        .logo-icon {
            width: 38px;
            height: 38px;
            border-radius: 9px;
            background: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
            font-weight: 800;
            flex-shrink: 0;
        }
        .logo span {
            white-space: nowrap;
        }
        .main-nav {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .main-nav a {
            display: inline-flex;
            align-items: center;
            padding: 8px 16px;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            position: relative;
            transition: var(--transition);
            white-space: nowrap;
        }
        .main-nav a:hover {
            color: var(--secondary);
            background: rgba(0,194,168,.06);
        }
        .main-nav a.active {
            color: var(--accent);
            font-weight: 600;
        }
        .main-nav a.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 16px;
            right: 16px;
            height: 3px;
            border-radius: 2px;
            background: var(--accent);
        }
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            padding: 8px;
            border-radius: 8px;
            transition: var(--transition);
            z-index: 1100;
        }
        .hamburger span {
            display: block;
            width: 24px;
            height: 2.5px;
            background: var(--primary);
            border-radius: 2px;
            transition: var(--transition);
        }
        .hamburger.open span:nth-child(1) {
            transform: translateY(7.5px) rotate(45deg);
        }
        .hamburger.open span:nth-child(2) {
            opacity: 0;
        }
        .hamburger.open span:nth-child(3) {
            transform: translateY(-7.5px) rotate(-45deg);
        }
        .mobile-overlay {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(20,24,40,.55);
            z-index: 1050;
            opacity: 0;
            transition: opacity .25s ease;
        }
        .mobile-overlay.show {
            opacity: 1;
        }
        .mobile-drawer {
            position: fixed;
            top: 0;
            right: -320px;
            width: 300px;
            max-width: 85vw;
            height: 100vh;
            background: #fff;
            z-index: 1060;
            padding: 80px 24px 40px;
            display: flex;
            flex-direction: column;
            transition: right .3s ease;
            box-shadow: -8px 0 40px rgba(20,24,40,.1);
        }
        .mobile-drawer.open {
            right: 0;
        }
        .mobile-drawer a {
            display: block;
            padding: 14px 16px;
            font-size: 16px;
            font-weight: 500;
            color: var(--text);
            border-radius: 10px;
            transition: var(--transition);
        }
        .mobile-drawer a:hover {
            background: var(--bg);
            color: var(--secondary);
        }
        .mobile-drawer a.active {
            color: var(--accent);
            font-weight: 600;
            background: rgba(255,90,60,.06);
        }
        /* Page Header - compact light style */
        .page-header {
            background: #fff;
            padding: 36px 0 30px;
            border-bottom: 1px solid var(--border);
            position: relative;
        }
        .breadcrumb {
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 8px;
            font-size: 13px;
            color: var(--text-secondary);
            margin-bottom: 14px;
        }
        .breadcrumb a {
            color: var(--text-secondary);
            transition: var(--transition);
        }
        .breadcrumb a:hover {
            color: var(--secondary);
        }
        .breadcrumb .sep {
            color: #b8bdc8;
            user-select: none;
        }
        .breadcrumb .current {
            color: var(--text);
            font-weight: 500;
        }
        .page-header h1 {
            font-size: 28px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 10px;
            line-height: 1.35;
            letter-spacing: .2px;
        }
        .page-header .stats-row {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            font-size: 13px;
            color: var(--text-secondary);
        }
        .page-header .stats-row span {
            display: inline-flex;
            align-items: center;
            gap: 6px;
        }
        .page-header .stats-row .stat-dot {
            width: 6px;
            height: 6px;
            border-radius: 50%;
            background: var(--secondary);
            display: inline-block;
        }
        /* Section base */
        section {
            padding: 56px 0;
        }
        .section-alt {
            background: #fff;
        }
        .section-label {
            display: inline-block;
            font-size: 13px;
            font-weight: 600;
            color: var(--secondary);
            letter-spacing: .8px;
            text-transform: uppercase;
            margin-bottom: 10px;
        }
        .section-title {
            font-size: 26px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 12px;
            line-height: 1.35;
        }
        .section-desc {
            font-size: 15px;
            color: var(--text-secondary);
            max-width: 720px;
            line-height: 1.7;
            margin: 0 0 32px;
        }
        /* Filter toolbar */
        .filter-bar {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            align-items: center;
            padding: 16px 18px;
            background: #fff;
            border-radius: var(--radius-card);
            border: 1px solid var(--border);
            box-shadow: var(--shadow-default);
        }
        .filter-label {
            font-size: 14px;
            font-weight: 600;
            color: var(--primary);
            margin-right: 6px;
        }
        .filter-tag {
            display: inline-flex;
            align-items: center;
            padding: 6px 14px;
            font-size: 13px;
            font-weight: 500;
            border-radius: 20px;
            background: var(--bg);
            color: var(--text-secondary);
            transition: var(--transition);
            cursor: pointer;
            border: 1px solid transparent;
        }
        .filter-tag:hover {
            color: var(--secondary);
            border-color: rgba(0,194,168,.35);
            background: rgba(0,194,168,.06);
        }
        .filter-tag.active {
            background: var(--secondary);
            color: #fff;
            font-weight: 600;
        }
        /* Post grid */
        .post-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .post-card {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            overflow: hidden;
            box-shadow: var(--shadow-default);
            transition: var(--transition);
        }
        .post-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }
        .post-card a {
            display: block;
            height: 100%;
        }
        .post-thumb {
            position: relative;
            aspect-ratio: 16/9;
            overflow: hidden;
            background: #E9EDF3;
        }
        .post-thumb img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform .4s ease;
        }
        .post-card:hover .post-thumb img {
            transform: scale(1.04);
        }
        .post-body {
            padding: 18px 18px 20px;
        }
        .post-tag {
            display: inline-block;
            font-size: 12px;
            font-weight: 600;
            padding: 3px 10px;
            border-radius: 20px;
            background: rgba(0,194,168,.08);
            color: var(--secondary);
            margin-bottom: 10px;
        }
        .post-body h3 {
            font-size: 17px;
            font-weight: 600;
            color: var(--text);
            margin: 0 0 8px;
            line-height: 1.45;
        }
        .post-body p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.65;
            margin: 0 0 12px;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .post-time {
            font-size: 12px;
            color: #9AA0AE;
        }
        .empty-state {
            text-align: center;
            padding: 50px 20px;
            background: #fff;
            border: 1px dashed var(--border);
            border-radius: var(--radius-card);
            color: var(--text-secondary);
            font-size: 15px;
        }
        /* Topic cards */
        .topic-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .topic-card {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            overflow: hidden;
            box-shadow: var(--shadow-default);
            transition: var(--transition);
            display: block;
        }
        .topic-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }
        .topic-card img {
            aspect-ratio: 16/9;
            object-fit: cover;
            width: 100%;
        }
        .topic-card-body {
            padding: 18px 18px 20px;
        }
        .topic-card-body h3 {
            font-size: 17px;
            font-weight: 600;
            color: var(--text);
            margin: 0 0 8px;
            line-height: 1.45;
        }
        .topic-card-body p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.65;
            margin: 0;
        }
        /* Tip banner */
        .tip-banner {
            background: var(--primary);
            color: #fff;
            border-radius: var(--radius-card);
            padding: 32px 36px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 24px;
            flex-wrap: wrap;
        }
        .tip-banner .tip-text h3 {
            font-size: 20px;
            font-weight: 700;
            margin: 0 0 6px;
        }
        .tip-banner .tip-text p {
            font-size: 14px;
            color: rgba(255,255,255,.72);
            margin: 0;
            line-height: 1.6;
        }
        /* CTA banner */
        .cta-banner {
            background: var(--secondary);
            color: #fff;
            border-radius: var(--radius-card);
            padding: 32px 36px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 24px;
            flex-wrap: wrap;
        }
        .cta-banner h3 {
            font-size: 20px;
            font-weight: 700;
            margin: 0 0 6px;
        }
        .cta-banner p {
            font-size: 14px;
            color: rgba(255,255,255,.82);
            margin: 0;
        }
        /* Buttons */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 12px 24px;
            font-size: 14px;
            font-weight: 600;
            border-radius: var(--radius-btn);
            transition: var(--transition);
            line-height: 1.5;
            gap: 8px;
            border: 2px solid transparent;
            white-space: nowrap;
        }
        .btn:focus {
            outline: 3px solid rgba(0,194,168,.35);
            outline-offset: 2px;
        }
        .btn-primary {
            background: var(--secondary);
            color: #fff;
        }
        .btn-primary:hover {
            background: #00a88f;
            transform: translateY(-1px);
            color: #fff;
        }
        .btn-primary:active {
            transform: translateY(0);
        }
        .btn-accent {
            background: var(--accent);
            color: #fff;
        }
        .btn-accent:hover {
            background: #e64a2e;
            transform: translateY(-1px);
            color: #fff;
        }
        .btn-outline-light {
            background: transparent;
            color: #fff;
            border-color: rgba(255,255,255,.55);
        }
        .btn-outline-light:hover {
            background: rgba(255,255,255,.1);
            border-color: #fff;
            color: #fff;
            transform: translateY(-1px);
        }
        .btn-dark {
            background: var(--primary);
            color: #fff;
        }
        .btn-dark:hover {
            background: #1e2335;
            color: #fff;
            transform: translateY(-1px);
        }
        /* FAQ */
        .faq-wrap {
            display: grid;
            grid-template-columns: 300px 1fr;
            gap: 40px;
            align-items: start;
        }
        .faq-left h2 {
            font-size: 26px;
            font-weight: 700;
            color: var(--primary);
            margin: 0 0 10px;
        }
        .faq-left p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
            margin: 0;
        }
        .accordion-item {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            margin-bottom: 12px;
            overflow: hidden;
            transition: var(--transition);
        }
        .accordion-item:hover {
            box-shadow: var(--shadow-default);
        }
        .accordion-btn {
            width: 100%;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 18px 20px;
            font-size: 15px;
            font-weight: 600;
            color: var(--text);
            background: var(--card);
            border: none;
            text-align: left;
            transition: var(--transition);
            cursor: pointer;
        }
        .accordion-btn:hover {
            color: var(--secondary);
        }
        .accordion-btn .icon {
            flex-shrink: 0;
            width: 24px;
            height: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            background: rgba(0,194,168,.1);
            color: var(--secondary);
            font-size: 16px;
            transition: var(--transition);
        }
        .accordion-item.open .accordion-btn .icon {
            transform: rotate(45deg);
        }
        .accordion-body {
            max-height: 0;
            overflow: hidden;
            transition: max-height .3s ease;
        }
        .accordion-item.open .accordion-body {
            max-height: 300px;
        }
        .accordion-body-inner {
            padding: 0 20px 18px;
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        /* Return CTA */
        .return-cta {
            text-align: center;
            background: var(--primary);
            color: #fff;
            border-radius: var(--radius-card);
            padding: 48px 36px;
        }
        .return-cta h2 {
            font-size: 26px;
            font-weight: 700;
            margin: 0 0 10px;
        }
        .return-cta p {
            font-size: 15px;
            color: rgba(255,255,255,.72);
            margin: 0 0 24px;
        }
        .return-cta .btn-group {
            display: flex;
            gap: 12px;
            justify-content: center;
            flex-wrap: wrap;
        }
        /* Footer */
        .site-footer {
            background: var(--primary);
            color: rgba(255,255,255,.75);
            padding: 56px 0 28px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 1.6fr 1fr 1fr 1fr;
            gap: 36px;
            padding-bottom: 32px;
            border-bottom: 1px solid rgba(255,255,255,.1);
        }
        .footer-brand .logo {
            color: #fff;
            margin-bottom: 14px;
        }
        .footer-brand p {
            font-size: 13px;
            line-height: 1.7;
            color: rgba(255,255,255,.55);
            margin: 0;
            max-width: 280px;
        }
        .footer-col h4 {
            font-size: 15px;
            font-weight: 600;
            color: #fff;
            margin: 0 0 14px;
        }
        .footer-col a {
            display: block;
            font-size: 13px;
            color: rgba(255,255,255,.55);
            padding: 5px 0;
            transition: var(--transition);
        }
        .footer-col a:hover {
            color: var(--secondary);
        }
        .footer-bottom {
            padding-top: 22px;
            text-align: center;
        }
        .footer-bottom p {
            font-size: 12px;
            color: rgba(255,255,255,.4);
            margin: 0;
        }
        /* Responsive */
        @media (max-width: 1024px) {
            :root {
                --nav-height: 62px;
            }
            .post-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .topic-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .faq-wrap {
                grid-template-columns: 1fr;
                gap: 24px;
            }
        }
        @media (max-width: 768px) {
            .main-nav {
                display: none;
            }
            .hamburger {
                display: flex;
            }
            .mobile-overlay {
                display: block;
            }
            .post-grid {
                grid-template-columns: 1fr;
            }
            .topic-grid {
                grid-template-columns: 1fr;
            }
            .page-header h1 {
                font-size: 22px;
            }
            .section-title {
                font-size: 22px;
            }
            .filter-bar {
                padding: 14px;
                gap: 8px;
            }
            .tip-banner, .cta-banner {
                flex-direction: column;
                text-align: center;
                padding: 24px 20px;
            }
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 24px;
            }
            section {
                padding: 40px 0;
            }
        }
        @media (max-width: 520px) {
            .page-header {
                padding: 24px 0 22px;
            }
            .page-header h1 {
                font-size: 20px;
            }
            .btn {
                width: 100%;
                justify-content: center;
            }
            .return-cta .btn-group {
                flex-direction: column;
            }
        }

/* roulang page: category2 */
:root {
            --primary: #141827;
            --secondary: #00C2A8;
            --accent: #FF5A3C;
            --bg: #F4F7FA;
            --card: #FFFFFF;
            --text: #1A1D29;
            --text-secondary: #5B6270;
            --border: #E6E9F0;
            --radius-card: 14px;
            --radius-btn: 10px;
            --shadow-default: 0 6px 24px rgba(20,24,40,.05);
            --shadow-hover: 0 12px 32px rgba(20,24,40,.12);
            --font-stack: 'PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,-apple-system,BlinkMacSystemFont,sans-serif;
            --transition: all .22s ease;
            --max-width: 1200px;
            --nav-height: 72px;
        }
        * { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
        body {
            font-family: var(--font-stack);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        img { max-width: 100%; height: auto; display: block; }
        a { text-decoration: none; color: inherit; transition: var(--transition); }
        button { font-family: inherit; cursor: pointer; border: none; background: none; }
        input, textarea, select { font-family: inherit; font-size: 16px; }
        .container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
        .section { padding: 70px 0; }
        .section-alt { background: #fff; }
        .section-head { margin-bottom: 40px; }
        .section-head h2 { font-size: 28px; font-weight: 700; color: var(--primary); margin-bottom: 12px; }
        .section-head p { color: var(--text-secondary); font-size: 15px; }
        .text-accent { color: var(--secondary); }
        .text-accent-red { color: var(--accent); }

        /* Header */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            height: var(--nav-height);
            background: rgba(255,255,255,.92);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            transition: var(--transition);
        }
        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 18px;
            color: var(--primary);
            letter-spacing: .3px;
            flex-shrink: 0;
        }
        .logo-icon {
            width: 38px;
            height: 38px;
            border-radius: 9px;
            background: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
            font-weight: 800;
            flex-shrink: 0;
        }
        .logo span { white-space: nowrap; }
        .main-nav { display: flex; align-items: center; gap: 6px; }
        .main-nav a {
            display: inline-flex;
            align-items: center;
            padding: 8px 16px;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            position: relative;
            transition: var(--transition);
            white-space: nowrap;
        }
        .main-nav a:hover { color: var(--secondary); background: rgba(0,194,168,.06); }
        .main-nav a.active { color: var(--accent); font-weight: 600; }
        .main-nav a.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 16px;
            right: 16px;
            height: 3px;
            border-radius: 2px;
            background: var(--accent);
        }
        .hamburger { display: none; flex-direction: column; gap: 5px; padding: 8px; border-radius: 8px; z-index: 1100; }
        .hamburger span { display: block; width: 24px; height: 2.5px; background: var(--primary); border-radius: 2px; transition: var(--transition); }
        .hamburger.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
        .hamburger.open span:nth-child(2) { opacity: 0; }
        .hamburger.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }
        .mobile-overlay { display: none; position: fixed; inset: 0; background: rgba(20,24,40,.55); z-index: 1050; opacity: 0; transition: opacity .25s ease; }
        .mobile-overlay.show { opacity: 1; }
        .mobile-drawer {
            position: fixed;
            top: 0;
            right: -320px;
            width: 300px;
            max-width: 85vw;
            height: 100vh;
            background: #fff;
            z-index: 1060;
            padding: 80px 24px 40px;
            display: flex;
            flex-direction: column;
            transition: right .3s ease;
            box-shadow: -8px 0 40px rgba(20,24,40,.1);
        }
        .mobile-drawer.open { right: 0; }
        .mobile-drawer a {
            display: block;
            padding: 14px 16px;
            font-size: 16px;
            font-weight: 500;
            color: var(--text);
            border-radius: 10px;
            transition: var(--transition);
        }
        .mobile-drawer a:hover { background: var(--bg); color: var(--secondary); }
        .mobile-drawer a.active { color: var(--accent); font-weight: 600; background: rgba(255,90,60,.06); }

        /* Page Header */
        .page-header {
            background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
            padding: 42px 0 44px;
            border-bottom: 1px solid var(--border);
        }
        .breadcrumb-nav { font-size: 14px; color: var(--text-secondary); margin-bottom: 16px; }
        .breadcrumb-nav a { color: var(--text-secondary); }
        .breadcrumb-nav a:hover { color: var(--secondary); }
        .breadcrumb-nav span { margin: 0 8px; color: #b0b5c0; }
        .page-header h1 { font-size: 34px; font-weight: 700; color: var(--primary); margin-bottom: 10px; }
        .page-header .header-meta { display: flex; flex-wrap: wrap; gap: 18px; color: var(--text-secondary); font-size: 14px; }
        .page-header .header-meta strong { color: var(--accent); font-weight: 600; }

        /* Filter Bar */
        .filter-bar {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            margin-bottom: 30px;
        }
        .filter-tag {
            display: inline-flex;
            align-items: center;
            padding: 8px 18px;
            border: 1px solid var(--border);
            border-radius: 20px;
            background: #fff;
            color: var(--text-secondary);
            font-size: 14px;
            font-weight: 500;
            transition: var(--transition);
            cursor: pointer;
        }
        .filter-tag:hover, .filter-tag:focus {
            border-color: var(--secondary);
            color: var(--secondary);
            background: rgba(0,194,168,.05);
        }
        .filter-tag.active {
            background: var(--secondary);
            color: #fff;
            border-color: var(--secondary);
        }

        /* Tutorial Cards */
        .tutorial-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .tutorial-card {
            background: var(--card);
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            overflow: hidden;
            transition: var(--transition);
            box-shadow: var(--shadow-default);
            display: flex;
            flex-direction: column;
        }
        .tutorial-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }
        .tutorial-card .card-img {
            position: relative;
            aspect-ratio: 16/9;
            overflow: hidden;
            background: #eef2f7;
        }
        .tutorial-card .card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .3s ease; }
        .tutorial-card:hover .card-img img { transform: scale(1.04); }
        .tutorial-card .card-body {
            padding: 22px 22px 20px;
            display: flex;
            flex-direction: column;
            flex: 1;
        }
        .tutorial-card .card-tag {
            display: inline-block;
            width: fit-content;
            padding: 4px 12px;
            border-radius: 12px;
            background: rgba(0,194,168,.1);
            color: #0aa18e;
            font-size: 12px;
            font-weight: 600;
            margin-bottom: 12px;
        }
        .tutorial-card h3 {
            font-size: 20px;
            font-weight: 600;
            line-height: 1.4;
            color: var(--primary);
            margin-bottom: 10px;
        }
        .tutorial-card p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.7;
            margin-bottom: 18px;
            flex: 1;
        }
        .tutorial-card .card-meta {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            font-size: 13px;
            color: #9aa0ac;
        }
        .tutorial-card .card-link {
            color: var(--secondary);
            font-weight: 600;
            font-size: 14px;
            display: inline-flex;
            align-items: center;
            gap: 4px;
        }
        .tutorial-card .card-link:hover { color: #009f8b; }

        /* Topic Recommend */
        .topic-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 22px;
        }
        .topic-card {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: var(--radius-card);
            padding: 26px 22px;
            text-align: center;
            transition: var(--transition);
            box-shadow: var(--shadow-default);
        }
        .topic-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: #d0eadd; }
        .topic-card .topic-icon {
            width: 54px;
            height: 54px;
            border-radius: 14px;
            background: rgba(0,194,168,.1);
            color: var(--secondary);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 26px;
            margin-bottom: 16px;
        }
        .topic-card h3 { font-size: 18px; font-weight: 600; color: var(--primary); margin-bottom: 8px; }
        .topic-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; margin-bottom: 14px; }
        .topic-card a { color: var(--accent); font-weight: 600; font-size: 14px; }

        /* Guide Tip Bar */
        .guide-tip-bar {
            background: #eefaf7;
            border-left: 4px solid var(--secondary);
            border-radius: 12px;
            padding: 28px 30px;
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 20px;
        }
        .guide-tip-bar .tip-content { flex: 1; min-width: 240px; }
        .guide-tip-bar .tip-content h3 { font-size: 20px; font-weight: 600; color: var(--primary); margin-bottom: 8px; }
        .guide-tip-bar .tip-content p { font-size: 15px; color: var(--text-secondary); }

        /* Download CTA */
        .cta-download {
            background: var(--primary);
            border-radius: 16px;
            padding: 48px 42px;
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 30px;
            color: #fff;
            position: relative;
            overflow: hidden;
        }
        .cta-download::after {
            content: '';
            position: absolute;
            right: -80px;
            top: -80px;
            width: 240px;
            height: 240px;
            background: rgba(0,194,168,.12);
            border-radius: 50%;
        }
        .cta-download .cta-content { flex: 1; min-width: 260px; position: relative; z-index: 1; }
        .cta-download h2 { font-size: 30px; font-weight: 700; margin-bottom: 10px; }
        .cta-download p { font-size: 15px; color: rgba(255,255,255,.78); margin-bottom: 0; }
        .cta-download .cta-actions { display: flex; flex-wrap: wrap; gap: 14px; position: relative; z-index: 1; }

        /* Buttons */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 12px 26px;
            font-size: 15px;
            font-weight: 600;
            border-radius: var(--radius-btn);
            transition: var(--transition);
            border: none;
            cursor: pointer;
            line-height: 1.2;
            gap: 6px;
        }
        .btn-primary {
            background: var(--accent);
            color: #fff;
            box-shadow: 0 8px 18px rgba(255,90,60,.22);
        }
        .btn-primary:hover { background: #e64a2c; transform: translateY(-1px); box-shadow: 0 10px 24px rgba(255,90,60,.3); }
        .btn-primary:active { transform: translateY(0); box-shadow: 0 6px 14px rgba(255,90,60,.2); }
        .btn-outline-light {
            background: transparent;
            color: #fff;
            border: 1.5px solid rgba(255,255,255,.5);
        }
        .btn-outline-light:hover { border-color: #fff; background: rgba(255,255,255,.08); transform: translateY(-1px); }
        .btn-secondary { background: var(--secondary); color: #fff; }
        .btn-secondary:hover { background: #00a992; transform: translateY(-1px); }
        .btn-ghost {
            background: #fff;
            color: var(--primary);
            border: 1px solid var(--border);
        }
        .btn-ghost:hover { border-color: var(--secondary); color: var(--secondary); transform: translateY(-1px); }
        .btn:focus-visible { outline: 3px solid rgba(0,194,168,.5); outline-offset: 2px; }

        /* FAQ Accordion */
        .faq-wrapper { max-width: 860px; margin: 0 auto; }
        .faq-item {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: 12px;
            margin-bottom: 14px;
            overflow: hidden;
            transition: var(--transition);
        }
        .faq-item:hover { border-color: #d0eadd; box-shadow: var(--shadow-default); }
        .faq-question {
            width: 100%;
            padding: 20px 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 18px;
            font-size: 16px;
            font-weight: 600;
            color: var(--primary);
            background: none;
            text-align: left;
            cursor: pointer;
            transition: var(--transition);
        }
        .faq-question:hover { color: var(--secondary); }
        .faq-question .faq-icon {
            flex-shrink: 0;
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: rgba(0,194,168,.1);
            color: var(--secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            transition: transform .25s ease;
        }
        .faq-item.open .faq-icon { transform: rotate(45deg); background: var(--secondary); color: #fff; }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height .3s ease;
            padding: 0 24px;
            color: var(--text-secondary);
            font-size: 15px;
            line-height: 1.8;
        }
        .faq-item.open .faq-answer {
            max-height: 300px;
            padding: 0 24px 22px;
        }

        /* Return CTA */
        .return-cta {
            text-align: center;
            padding: 50px 24px;
            background: #fff;
            border-top: 1px solid var(--border);
        }
        .return-cta h3 { font-size: 24px; font-weight: 700; color: var(--primary); margin-bottom: 10px; }
        .return-cta p { color: var(--text-secondary); margin-bottom: 22px; }

        /* Footer */
        .site-footer {
            background: var(--primary);
            color: rgba(255,255,255,.78);
            padding: 60px 0 24px;
            margin-top: 60px;
        }
        .site-footer .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }
        .footer-brand .logo { color: #fff; margin-bottom: 18px; }
        .footer-brand p { font-size: 14px; line-height: 1.8; color: rgba(255,255,255,.64); max-width: 320px; }
        .footer-col h4 { font-size: 16px; font-weight: 600; color: #fff; margin-bottom: 16px; }
        .footer-col a {
            display: block;
            font-size: 14px;
            color: rgba(255,255,255,.64);
            margin-bottom: 10px;
            transition: var(--transition);
        }
        .footer-col a:hover { color: var(--secondary); padding-left: 4px; }
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,.1);
            padding-top: 20px;
            text-align: center;
            font-size: 13px;
            color: rgba(255,255,255,.5);
        }

        /* Responsive */
        @media (max-width: 1024px) {
            .tutorial-grid { grid-template-columns: repeat(2, 1fr); }
            .topic-grid { grid-template-columns: repeat(2, 1fr); }
        }
        @media (max-width: 768px) {
            :root { --nav-height: 62px; }
            .main-nav { display: none; }
            .hamburger { display: flex; }
            .mobile-overlay { display: block; }
            .mobile-drawer { display: flex; }
            .section { padding: 50px 0; }
            .page-header h1 { font-size: 28px; }
            .tutorial-grid { grid-template-columns: 1fr; }
            .topic-grid { grid-template-columns: 1fr; }
            .filter-bar { gap: 8px; }
            .cta-download { padding: 36px 28px; }
            .cta-download h2 { font-size: 24px; }
            .site-footer .footer-grid { grid-template-columns: 1fr; gap: 28px; }
        }
        @media (max-width: 520px) {
            .container { padding: 0 18px; }
            .main-nav a { padding: 8px 12px; font-size: 13px; }
            .page-header h1 { font-size: 24px; }
            .btn { padding: 10px 20px; font-size: 14px; }
        }