/* roulang page: index */
:root {
            --bg-deep: #08090F;
            --bg-primary: #0D111E;
            --bg-card: rgba(13, 17, 30, 0.6);
            --accent-electric: #0052FF;
            --accent-cyan: #00F0FF;
            --accent-glow: rgba(0, 240, 255, 0.5);
            --text-white: #FFFFFF;
            --text-silver: #CBD5E1;
            --text-muted: #64748B;
            --border-glass: rgba(255, 255, 255, 0.08);
            --border-electric: rgba(0, 82, 255, 0.4);
            --radius-lg: 20px;
            --radius-md: 14px;
            --radius-sm: 10px;
            --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
            --shadow-glow: 0 0 15px var(--accent-glow);
            --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        body {
            font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
            background: var(--bg-deep);
            color: var(--text-silver);
            line-height: 1.6;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

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

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

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

        button,
        .btn {
            transition: var(--transition-smooth);
            border-radius: 30px;
            font-weight: 600;
            letter-spacing: 0.3px;
        }

        .container-custom {
            max-width: 1260px;
            padding-left: 24px;
            padding-right: 24px;
            margin-left: auto;
            margin-right: auto;
        }

        /* Navigation */
        .navbar-main {
            background: rgba(8, 9, 15, 0.82);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            border-bottom: 1px solid var(--border-glass);
            padding: 14px 0;
            position: sticky;
            top: 0;
            z-index: 1050;
            transition: var(--transition-smooth);
        }

        .navbar-brand-custom {
            font-size: 1.25rem;
            font-weight: 700;
            background: linear-gradient(135deg, var(--accent-cyan), var(--accent-electric));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            letter-spacing: -0.3px;
        }

        .nav-link-custom {
            color: var(--text-silver) !important;
            font-weight: 500;
            margin: 0 6px;
            padding: 8px 16px !important;
            border-radius: 30px;
            transition: var(--transition-smooth);
            position: relative;
        }

        .nav-link-custom:hover,
        .nav-link-custom.active {
            color: var(--text-white) !important;
            background: rgba(0, 240, 255, 0.08);
        }

        .nav-link-custom.active {
            background: rgba(0, 82, 255, 0.15);
            border-left: 2px solid var(--accent-cyan);
        }

        /* Glass morph */
        .glass-card {
            background: var(--bg-card);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border: 1px solid var(--border-glass);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-card);
        }

        .glass-btn {
            background: rgba(255, 255, 255, 0.06);
            border: 1px solid rgba(255, 255, 255, 0.15);
            backdrop-filter: blur(8px);
            color: var(--text-white);
        }

        .glass-btn:hover {
            background: rgba(0, 240, 255, 0.12);
            border-color: var(--accent-cyan);
            color: var(--text-white);
        }

        .btn-electric {
            background: var(--accent-electric);
            border: none;
            color: #fff;
            box-shadow: 0 4px 18px rgba(0, 82, 255, 0.5);
            font-weight: 600;
            padding: 10px 28px;
        }

        .btn-electric:hover {
            background: #1a66ff;
            box-shadow: 0 0 24px rgba(0, 240, 255, 0.7);
            color: #fff;
            transform: translateY(-1px);
        }

        .btn-outline-glow {
            background: transparent;
            border: 1.5px solid var(--accent-cyan);
            color: var(--accent-cyan);
            box-shadow: 0 0 10px rgba(0, 240, 255, 0.3);
        }

        .btn-outline-glow:hover {
            background: var(--accent-cyan);
            color: #08090F;
            border-color: var(--accent-cyan);
        }

        /* Hero */
        .hero-section {
            background-image: url('/assets/images/backpic/back-1.png');
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            position: relative;
            padding: 80px 0 90px;
        }

        .hero-overlay {
            position: absolute;
            inset: 0;
            background: linear-gradient(90deg, rgba(8,9,15,0.88) 0%, rgba(8,9,15,0.5) 70%, rgba(8,9,15,0.8) 100%);
            z-index: 1;
        }

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

        .ebook-mockup {
            background: rgba(13,17,30,0.75);
            backdrop-filter: blur(13px);
            border: 1px solid rgba(0,240,255,0.2);
            border-radius: 18px;
            padding: 32px 28px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.55);
        }

        .tag-glow {
            display: inline-block;
            background: rgba(0, 240, 255, 0.12);
            color: var(--accent-cyan);
            padding: 6px 18px;
            border-radius: 30px;
            font-size: 0.85rem;
            font-weight: 600;
            border: 1px solid rgba(0, 240, 255, 0.3);
        }

        h1 {
            font-weight: 800;
            line-height: 1.15;
            color: var(--text-white);
            font-size: 2.8rem;
        }

        .text-neon {
            color: var(--accent-cyan);
            text-shadow: 0 0 8px rgba(0,240,255,0.7);
        }

        /* Section titles */
        .section-title {
            font-weight: 700;
            font-size: 2rem;
            color: var(--text-white);
            margin-bottom: 0.75rem;
        }

        .section-desc {
            color: var(--text-silver);
            max-width: 680px;
            margin-bottom: 2rem;
            line-height: 1.65;
        }

        /* Cards */
        .feature-card {
            background: var(--bg-card);
            backdrop-filter: blur(12px);
            border: 1px solid var(--border-electric);
            border-radius: 20px;
            padding: 28px 24px;
            box-shadow: 0 10px 28px rgba(0,0,0,0.45);
            transition: all 0.25s ease;
            height: 100%;
        }

        .feature-card:hover {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 22px rgba(0,240,255,0.3);
            transform: translateY(-5px);
        }

        .rank-list-item {
            background: rgba(255,255,255,0.03);
            border-left: 4px solid var(--accent-electric);
            padding: 16px 20px;
            border-radius: 12px;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            color: var(--text-silver);
        }

        .vertical-card {
            background: var(--bg-card);
            border-radius: 20px;
            overflow: hidden;
            border: 1px solid var(--border-glass);
            transition: all 0.25s;
        }

        .vertical-card:hover {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 20px rgba(0,240,255,0.25);
        }

        .faq-accordion-item {
            background: transparent;
            border-bottom: 1px solid var(--border-glass);
        }

        .faq-accordion-button {
            background: transparent;
            color: var(--text-white);
            font-weight: 600;
            padding: 18px 0;
            border: none;
            width: 100%;
            text-align: left;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .faq-accordion-button:hover {
            color: var(--accent-cyan);
        }

        .footer-site {
            background: var(--bg-primary);
            border-top: 1px solid var(--border-glass);
            padding: 48px 0 24px;
            color: var(--text-muted);
        }

        /* FAB Neon Style */
        .fab-neon {
            position: fixed;
            left: 20px;
            bottom: 96px;
            z-index: 1055;
            width: 54px;
            height: 54px;
            background: rgba(8,9,15,0.7);
            backdrop-filter: blur(12px);
            border: 1.5px solid transparent;
            background-clip: padding-box;
            border-radius: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--accent-cyan);
            box-shadow: 0 0 18px rgba(0,240,255,0.7);
            transition: all 0.2s;
            cursor: pointer;
            opacity: 0.65;
        }

        .fab-neon:hover {
            opacity: 1;
            transform: scale(1.12);
            box-shadow: 0 0 28px rgba(0,240,255,0.9);
            color: #fff;
        }

        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }
            .hero-section {
                padding: 45px 0 55px;
            }
            .fab-neon {
                width: 48px;
                height: 48px;
                left: 14px;
                bottom: 80px;
            }
        }

/* roulang page: article */
:root {
            --bg-deep: #08090F;
            --bg-card: #0D111E;
            --bg-nav: rgba(8, 9, 15, 0.92);
            --accent-blue: #0052FF;
            --accent-cyan: #00F0FF;
            --text-primary: #FFFFFF;
            --text-silver: #CBD5E1;
            --text-muted: #94A3B8;
            --border-subtle: rgba(0, 240, 255, 0.15);
            --border-glow: rgba(0, 240, 255, 0.45);
            --shadow-neon: 0 0 18px rgba(0, 240, 255, 0.15);
            --shadow-btn: 0 0 22px rgba(0, 82, 255, 0.5);
            --radius-lg: 18px;
            --radius-md: 12px;
            --radius-sm: 8px;
            --transition-fast: 0.18s ease;
            --transition-smooth: 0.28s cubic-bezier(0.23, 1, 0.32, 1);
        }

        * {
            box-sizing: border-box;
        }

        body {
            background-color: var(--bg-deep);
            color: var(--text-silver);
            font-family: 'Inter', 'Segoe UI', 'Roboto', system-ui, -apple-system, sans-serif;
            line-height: 1.6;
            margin: 0;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

        .container-custom {
            max-width: 1200px;
            margin: 0 auto;
            padding-left: 20px;
            padding-right: 20px;
        }

        .navbar-main {
            position: sticky;
            top: 0;
            z-index: 1050;
            background: var(--bg-nav);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-bottom: 1px solid var(--border-subtle);
            padding: 12px 0;
            transition: background var(--transition-smooth);
        }

        .navbar-brand-custom {
            font-weight: 700;
            font-size: 1.25rem;
            color: var(--text-primary);
            text-decoration: none;
            letter-spacing: -0.3px;
            transition: color var(--transition-fast);
        }

        .navbar-brand-custom:hover {
            color: var(--accent-cyan);
        }

        .nav-link-custom {
            font-weight: 500;
            font-size: 0.92rem;
            color: var(--text-silver);
            text-decoration: none;
            padding: 7px 16px;
            border-radius: 24px;
            transition: all var(--transition-fast);
            letter-spacing: -0.2px;
            position: relative;
        }

        .nav-link-custom:hover,
        .nav-link-custom.active {
            color: var(--text-primary);
            background: rgba(0, 240, 255, 0.08);
        }

        .btn-electric {
            background: var(--accent-blue);
            border: none;
            color: white;
            font-weight: 600;
            font-size: 0.9rem;
            padding: 8px 22px;
            border-radius: 26px;
            box-shadow: 0 0 14px rgba(0, 82, 255, 0.5);
            transition: all var(--transition-smooth);
            letter-spacing: -0.3px;
            white-space: nowrap;
        }

        .btn-electric:hover {
            background: #1a6fff;
            box-shadow: 0 0 26px rgba(0, 82, 255, 0.8);
            transform: translateY(-1px);
            color: white;
        }

        .btn-electric:active {
            transform: scale(0.97);
        }

        .text-silver {
            color: var(--text-silver);
            cursor: pointer;
            transition: color var(--transition-fast);
            font-size: 0.9rem;
            font-weight: 500;
        }

        .text-silver:hover {
            color: var(--accent-cyan);
        }

        .article-hero {
            background: linear-gradient(135deg, #0D111E 0%, #08090F 100%);
            border-bottom: 1px solid var(--border-subtle);
            padding: 48px 0 44px;
            position: relative;
        }

        .article-hero::after {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background: linear-gradient(90deg, transparent 0%, var(--accent-cyan) 50%, transparent 100%);
            opacity: 0.5;
        }

        .article-category-badge {
            display: inline-block;
            background: rgba(0, 240, 255, 0.08);
            border: 1px solid var(--border-glow);
            color: var(--accent-cyan);
            font-weight: 600;
            font-size: 0.8rem;
            padding: 5px 16px;
            border-radius: 20px;
            letter-spacing: 0.3px;
            text-transform: uppercase;
            margin-bottom: 16px;
        }

        .article-title {
            font-size: 2.6rem;
            font-weight: 800;
            color: var(--text-primary);
            line-height: 1.3;
            letter-spacing: -0.5px;
            margin-bottom: 14px;
        }

        .article-meta {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            font-size: 0.88rem;
            color: var(--text-muted);
            border-top: 1px solid rgba(255, 255, 255, 0.06);
            padding-top: 18px;
            margin-top: 8px;
        }

        .article-meta i {
            color: var(--accent-cyan);
            margin-right: 6px;
            font-size: 0.8rem;
        }

        .article-content-wrapper {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: 40px 36px;
            margin: 36px 0 50px;
            box-shadow: var(--shadow-neon);
            color: var(--text-silver);
            line-height: 1.75;
            font-size: 1.05rem;
        }

        .article-content-wrapper h2 {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-top: 32px;
            margin-bottom: 16px;
            letter-spacing: -0.4px;
        }

        .article-content-wrapper h3 {
            font-size: 1.4rem;
            font-weight: 600;
            color: var(--accent-cyan);
            margin-top: 24px;
            margin-bottom: 12px;
        }

        .article-content-wrapper p {
            margin-bottom: 18px;
        }

        .article-content-wrapper ul,
        .article-content-wrapper ol {
            padding-left: 24px;
            margin-bottom: 20px;
        }

        .article-content-wrapper li {
            margin-bottom: 8px;
        }

        .article-content-wrapper a {
            color: var(--accent-cyan);
            text-decoration: underline;
            text-underline-offset: 4px;
        }

        .article-content-wrapper blockquote {
            border-left: 4px solid var(--accent-cyan);
            background: rgba(0, 240, 255, 0.03);
            padding: 18px 24px;
            border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
            margin: 24px 0;
            font-style: italic;
            color: var(--text-silver);
        }

        .not-found-box {
            text-align: center;
            padding: 70px 20px;
            color: var(--text-muted);
        }

        .not-found-box i {
            font-size: 3rem;
            color: var(--accent-cyan);
            opacity: 0.7;
            margin-bottom: 20px;
        }

        .btn-back-home {
            display: inline-block;
            margin-top: 24px;
            background: transparent;
            border: 1px solid var(--accent-cyan);
            color: var(--accent-cyan);
            font-weight: 600;
            padding: 10px 28px;
            border-radius: 28px;
            text-decoration: none;
            transition: all var(--transition-smooth);
        }

        .btn-back-home:hover {
            background: rgba(0, 240, 255, 0.08);
            color: white;
        }

        .cta-download-banner {
            background: linear-gradient(135deg, #0D111E, #0052FF22);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: 38px 34px;
            margin: 50px 0 30px;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            gap: 24px;
            backdrop-filter: blur(10px);
        }

        .cta-download-banner .cta-text h4 {
            color: var(--text-primary);
            font-weight: 700;
            font-size: 1.5rem;
            margin-bottom: 6px;
        }

        .cta-download-banner .cta-text p {
            color: var(--text-silver);
            margin: 0;
            font-size: 0.95rem;
        }

        .footer-site {
            background: #05070D;
            border-top: 1px solid var(--border-subtle);
            padding: 32px 0;
            margin-top: 50px;
        }

        .footer-site p {
            color: var(--text-muted);
            font-size: 0.85rem;
            line-height: 1.7;
        }

        .fab-floating {
            position: fixed;
            left: 20px;
            bottom: 90px;
            z-index: 1200;
            width: 52px;
            height: 52px;
            background: rgba(8, 9, 15, 0.7);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            border: 1.5px solid transparent;
            border-image: linear-gradient(135deg, #00F0FF, #0052FF) 1;
            border-radius: 30px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--accent-cyan);
            font-size: 1.5rem;
            box-shadow: 0 0 20px rgba(0, 240, 255, 0.35);
            transition: all 0.25s ease;
            cursor: pointer;
            opacity: 0.75;
        }

        .fab-floating:hover {
            opacity: 1;
            transform: scale(1.1);
            box-shadow: 0 0 32px rgba(0, 240, 255, 0.65);
        }

        @media (max-width: 992px) {
            .article-title {
                font-size: 2rem;
            }
            .article-content-wrapper {
                padding: 28px 20px;
            }
        }

        @media (max-width: 768px) {
            .navbar-main .container-custom {
                flex-wrap: wrap;
            }
            .article-title {
                font-size: 1.7rem;
            }
            .cta-download-banner {
                flex-direction: column;
                text-align: center;
            }
            .fab-floating {
                width: 46px;
                height: 46px;
                left: 14px;
                bottom: 70px;
            }
        }

        @media (max-width: 520px) {
            .article-title {
                font-size: 1.5rem;
            }
            .article-meta {
                gap: 12px;
                font-size: 0.8rem;
            }
            .navbar-brand-custom {
                font-size: 1.1rem;
            }
        }

/* roulang page: category2 */
:root {
            --deep-blue: #08090F;
            --cyber-navy: #0D111E;
            --electric-blue: #0052FF;
            --neon-cyan: #00F0FF;
            --text-white: #FFFFFF;
            --text-silver: #CBD5E1;
            --card-bg: rgba(18, 22, 38, 0.7);
            --card-border: rgba(0, 82, 255, 0.2);
            --shadow-glow: 0 8px 32px rgba(0, 82, 255, 0.15);
            --border-radius-lg: 1.25rem;
            --border-radius-md: 0.875rem;
            --border-radius-sm: 0.625rem;
            --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        * {
            box-sizing: border-box;
        }

        body {
            background: var(--deep-blue);
            color: var(--text-silver);
            font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
            line-height: 1.6;
            margin: 0;
            padding: 0;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

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

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

        button {
            transition: var(--transition-smooth);
        }

        /* Container */
        .container-custom {
            width: 100%;
            max-width: 1240px;
            padding-left: 1.5rem;
            padding-right: 1.5rem;
            margin-left: auto;
            margin-right: auto;
        }

        /* Navigation */
        .navbar-main {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1050;
            background: rgba(8, 9, 15, 0.85);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-bottom: 1px solid rgba(0, 82, 255, 0.2);
            padding: 0.8rem 0;
            box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
        }

        .navbar-brand-custom {
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--text-white);
            letter-spacing: -0.3px;
            white-space: nowrap;
            background: linear-gradient(135deg, #FFFFFF 0%, var(--neon-cyan) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .nav-link-custom {
            font-size: 0.9rem;
            font-weight: 500;
            color: var(--text-silver);
            padding: 0.5rem 1rem;
            border-radius: 2rem;
            transition: var(--transition-smooth);
            position: relative;
        }

        .nav-link-custom:hover {
            color: var(--text-white);
            background: rgba(0, 82, 255, 0.15);
        }

        .nav-link-custom.active {
            color: var(--text-white);
            background: var(--electric-blue);
            box-shadow: 0 0 16px rgba(0, 82, 255, 0.4);
        }

        .btn-electric {
            background: linear-gradient(135deg, var(--electric-blue), #0039CC);
            color: var(--text-white);
            font-weight: 600;
            font-size: 0.875rem;
            padding: 0.55rem 1.5rem;
            border-radius: 2rem;
            border: none;
            box-shadow: 0 4px 16px rgba(0, 82, 255, 0.3);
            transition: var(--transition-smooth);
        }

        .btn-electric:hover {
            background: linear-gradient(135deg, #336DFF, #004DE6);
            box-shadow: 0 6px 24px rgba(0, 82, 255, 0.5);
            transform: translateY(-1px);
            color: var(--text-white);
        }

        .btn-electric:active {
            transform: translateY(0);
            box-shadow: 0 2px 8px rgba(0, 82, 255, 0.3);
        }

        .text-silver {
            color: var(--text-silver);
            font-size: 0.9rem;
            cursor: pointer;
            transition: var(--transition-smooth);
        }

        .text-silver:hover {
            color: var(--text-white);
        }

        /* Page Header / Banner */
        .page-banner {
            padding-top: 7rem;
            padding-bottom: 3rem;
            position: relative;
            background-image: url('/assets/images/backpic/back-3.png');
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            min-height: 380px;
            display: flex;
            align-items: center;
        }

        .page-banner::before {
            content: '';
            position: absolute;
            inset: 0;
            background: linear-gradient(180deg, rgba(8, 9, 15, 0.85) 0%, rgba(13, 17, 30, 0.92) 100%);
            z-index: 1;
        }

        .page-banner-content {
            position: relative;
            z-index: 2;
            width: 100%;
        }

        /* Glass Cards */
        .glass-card {
            background: var(--card-bg);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border: 1px solid var(--card-border);
            border-radius: var(--border-radius-lg);
            box-shadow: var(--shadow-glow);
            transition: var(--transition-smooth);
        }

        .glass-card:hover {
            border-color: rgba(0, 240, 255, 0.4);
            box-shadow: 0 12px 40px rgba(0, 240, 255, 0.12);
            transform: translateY(-3px);
        }

        .stat-number {
            font-size: 2.8rem;
            font-weight: 800;
            color: var(--text-white);
            line-height: 1;
            background: linear-gradient(180deg, #FFFFFF 0%, var(--neon-cyan) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .stat-label {
            font-size: 0.875rem;
            color: var(--text-silver);
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 0.8px;
            margin-top: 0.25rem;
        }

        .tool-icon-box {
            width: 64px;
            height: 64px;
            border-radius: var(--border-radius-md);
            background: rgba(0, 82, 255, 0.15);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.75rem;
            color: var(--neon-cyan);
            border: 1px solid rgba(0, 240, 255, 0.3);
        }

        .faq-item {
            background: var(--card-bg);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border: 1px solid var(--card-border);
            border-radius: var(--border-radius-md);
            margin-bottom: 1rem;
            overflow: hidden;
        }

        .faq-question {
            padding: 1.25rem 1.5rem;
            cursor: pointer;
            font-weight: 600;
            color: var(--text-white);
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: var(--transition-smooth);
        }

        .faq-question:hover {
            background: rgba(0, 82, 255, 0.08);
        }

        .faq-answer {
            padding: 0 1.5rem 1.25rem;
            color: var(--text-silver);
            font-size: 0.95rem;
            line-height: 1.7;
        }

        .feature-highlight {
            border-left: 3px solid var(--neon-cyan);
            padding-left: 1.25rem;
        }

        /* Footer */
        .footer-site {
            background: rgba(8, 9, 15, 0.95);
            border-top: 1px solid rgba(0, 82, 255, 0.25);
            padding: 2rem 0;
            color: var(--text-silver);
            font-size: 0.9rem;
            text-align: center;
        }

        /* Mobile Nav */
        @media (max-width: 768px) {
            .navbar-brand-custom {
                font-size: 1rem;
            }
            .page-banner {
                min-height: 280px;
                padding-top: 6rem;
                padding-bottom: 2rem;
            }
            .stat-number {
                font-size: 2rem;
            }
        }

/* roulang page: category1 */
:root {
            --bg-deep: #08090F;
            --bg-cyber: #0D111E;
            --accent-blue: #0052FF;
            --accent-cyan: #00F0FF;
            --text-white: #FFFFFF;
            --text-silver: #CBD5E1;
            --text-muted: #94A3B8;
            --border-glow: rgba(0,240,255,0.3);
            --card-bg: rgba(13,17,30,0.8);
            --card-border: rgba(0,82,255,0.2);
            --shadow-neon: 0 0 20px rgba(0,240,255,0.15);
            --shadow-elevated: 0 8px 32px rgba(0,0,0,0.4);
            --radius-lg: 16px;
            --radius-md: 12px;
            --radius-sm: 8px;
            --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        * {
            box-sizing: border-box;
        }

        body {
            background: var(--bg-deep);
            color: var(--text-silver);
            font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
            line-height: 1.6;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

        .container-custom {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Navigation */
        .navbar-main {
            background: rgba(8,9,15,0.95);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-bottom: 1px solid rgba(0,82,255,0.15);
            padding: 14px 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            transition: var(--transition-smooth);
        }

        .navbar-brand-custom {
            font-weight: 700;
            font-size: 1.4rem;
            color: var(--text-white) !important;
            text-decoration: none;
            letter-spacing: -0.3px;
            background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .nav-link-custom {
            color: var(--text-silver);
            text-decoration: none;
            font-weight: 500;
            font-size: 0.95rem;
            padding: 8px 16px;
            border-radius: 50px;
            transition: var(--transition-fast);
            position: relative;
        }

        .nav-link-custom:hover,
        .nav-link-custom.active {
            color: var(--accent-cyan);
            background: rgba(0,240,255,0.08);
        }

        .btn-electric {
            background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
            border: none;
            color: var(--text-white);
            font-weight: 600;
            padding: 10px 24px;
            border-radius: 50px;
            transition: var(--transition-fast);
            box-shadow: 0 4px 15px rgba(0,82,255,0.3);
        }

        .btn-electric:hover {
            box-shadow: 0 6px 25px rgba(0,240,255,0.5);
            transform: translateY(-1px);
            color: var(--text-white);
        }

        .btn-electric-outline {
            background: transparent;
            border: 2px solid var(--accent-cyan);
            color: var(--accent-cyan);
            font-weight: 600;
            padding: 10px 24px;
            border-radius: 50px;
            transition: var(--transition-fast);
        }

        .btn-electric-outline:hover {
            background: rgba(0,240,255,0.1);
            box-shadow: 0 0 20px rgba(0,240,255,0.2);
            color: var(--accent-cyan);
        }

        .text-silver {
            color: var(--text-silver);
        }

        /* Hero Section */
        .hero-category {
            padding: 80px 0 60px;
            position: relative;
            overflow: hidden;
            background: linear-gradient(180deg, var(--bg-cyber) 0%, var(--bg-deep) 100%);
            border-bottom: 1px solid rgba(0,240,255,0.1);
        }

        .hero-category::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle at 30% 50%, rgba(0,82,255,0.08) 0%, transparent 50%),
                        radial-gradient(circle at 70% 50%, rgba(0,240,255,0.05) 0%, transparent 50%);
            pointer-events: none;
        }

        .hero-badge {
            display: inline-block;
            background: rgba(0,240,255,0.1);
            border: 1px solid rgba(0,240,255,0.3);
            color: var(--accent-cyan);
            padding: 6px 18px;
            border-radius: 50px;
            font-weight: 600;
            font-size: 0.85rem;
            letter-spacing: 0.5px;
        }

        .glass-card {
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--card-border);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-neon);
        }

        .glass-card:hover {
            border-color: rgba(0,240,255,0.5);
            box-shadow: 0 0 30px rgba(0,240,255,0.2);
        }

        /* Strategy Cards */
        .strategy-card {
            background: var(--card-bg);
            backdrop-filter: blur(8px);
            border: 1px solid var(--card-border);
            border-radius: var(--radius-md);
            padding: 28px 24px;
            transition: var(--transition-smooth);
            position: relative;
            overflow: hidden;
        }

        .strategy-card::after {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background: linear-gradient(90deg, transparent, var(--accent-cyan), transparent);
            opacity: 0;
            transition: var(--transition-smooth);
        }

        .strategy-card:hover {
            border-color: rgba(0,240,255,0.5);
            transform: translateY(-4px);
            box-shadow: 0 12px 40px rgba(0,0,0,0.5);
        }

        .strategy-card:hover::after {
            opacity: 1;
        }

        .strategy-icon {
            width: 56px;
            height: 56px;
            background: linear-gradient(135deg, rgba(0,82,255,0.2), rgba(0,240,255,0.1));
            border: 1px solid var(--border-glow);
            border-radius: var(--radius-sm);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            color: var(--accent-cyan);
            margin-bottom: 20px;
        }

        .step-number {
            background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 1.1rem;
            color: var(--text-white);
            flex-shrink: 0;
        }

        .divider-glow {
            height: 1px;
            background: linear-gradient(90deg, transparent, rgba(0,240,255,0.3), transparent);
            margin: 30px 0;
        }

        /* Data Highlight */
        .data-highlight {
            background: rgba(0,82,255,0.08);
            border-left: 3px solid var(--accent-cyan);
            padding: 16px 20px;
            border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
        }

        /* FAQ */
        .faq-accordion .accordion-item {
            background: transparent;
            border: 1px solid var(--card-border);
            border-radius: var(--radius-sm) !important;
            margin-bottom: 12px;
            overflow: hidden;
        }

        .faq-accordion .accordion-button {
            background: var(--card-bg);
            color: var(--text-white);
            font-weight: 600;
            box-shadow: none;
            padding: 18px 24px;
            border-radius: var(--radius-sm) !important;
        }

        .faq-accordion .accordion-button:not(.collapsed) {
            background: rgba(0,240,255,0.05);
            color: var(--accent-cyan);
            border-bottom: 1px solid rgba(0,240,255,0.2);
        }

        .faq-accordion .accordion-button::after {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%2300F0FF'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
        }

        .faq-accordion .accordion-body {
            background: var(--bg-deep);
            color: var(--text-silver);
            padding: 20px 24px;
        }

        /* Footer */
        .footer-site {
            background: rgba(8,9,15,0.98);
            border-top: 1px solid rgba(0,82,255,0.15);
            padding: 30px 0;
            margin-top: 60px;
        }

        /* FAB */
        .fab-custom {
            position: fixed;
            left: 20px;
            bottom: 100px;
            z-index: 999;
            width: 56px;
            height: 56px;
            background: rgba(8,9,15,0.75);
            backdrop-filter: blur(12px);
            border: 2px solid;
            border-image: linear-gradient(135deg, #00F0FF, #0052FF) 1;
            border-radius: 50px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #00F0FF;
            font-size: 1.3rem;
            cursor: pointer;
            transition: var(--transition-smooth);
            box-shadow: 0 0 18px rgba(0,240,255,0.4);
            opacity: 0.65;
            animation: fabFloat 3s ease-in-out infinite;
        }

        .fab-custom:hover {
            opacity: 1;
            box-shadow: 0 0 28px rgba(0,240,255,0.7);
            transform: scale(1.08);
        }

        @keyframes fabFloat {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-6px); }
        }

        @keyframes flowLight {
            0% { background-position: 0% 50%; }
            100% { background-position: 400% 50%; }
        }

        .fab-custom::after {
            content: '';
            position: absolute;
            inset: -2px;
            border-radius: 50px;
            background: linear-gradient(90deg, transparent, rgba(0,240,255,0.5), transparent);
            background-size: 400% 100%;
            animation: flowLight 2s linear infinite;
            z-index: -1;
            filter: blur(8px);
        }

        @media (max-width: 768px) {
            .hero-category {
                padding: 50px 0 40px;
            }

            .navbar-brand-custom {
                font-size: 1.1rem;
            }

            .glass-card {
                padding: 20px;
            }

            .strategy-card {
                padding: 20px 18px;
            }

            .fab-custom {
                width: 48px;
                height: 48px;
                left: 12px;
                bottom: 80px;
                font-size: 1.1rem;
            }
        }

/* roulang page: category3 */
:root {
            --bg-deep-space: #08090F;
            --bg-cyber-navy: #0D111E;
            --surface-glass: rgba(18, 24, 40, 0.7);
            --border-glass: rgba(0, 82, 255, 0.25);
            --accent-blue: #0052FF;
            --accent-cyan: #00F0FF;
            --text-white: #FFFFFF;
            --text-silver: #CBD5E1;
            --text-muted: #94A3B8;
            --shadow-neon: 0 0 18px rgba(0, 240, 255, 0.25);
            --shadow-card: 0 12px 30px rgba(0, 0, 0, 0.6);
            --border-radius-lg: 32px;
            --border-radius-md: 20px;
            --border-radius-sm: 12px;
            --font-heading: 'Segoe UI', 'Inter', system-ui, -apple-system, sans-serif;
            --font-body: 'Segoe UI', 'Inter', system-ui, -apple-system, sans-serif;
            --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        * {
            box-sizing: border-box;
        }

        body {
            background: radial-gradient(circle at 20% 10%, #0D1A3A, #08090F 70%);
            font-family: var(--font-body);
            color: var(--text-silver);
            line-height: 1.6;
            margin: 0;
            overflow-x: hidden;
            backdrop-filter: blur(2px);
        }

        .container-custom {
            max-width: 1280px;
            margin: 0 auto;
            padding-left: 20px;
            padding-right: 20px;
        }

        /* ---- Navigation Shared ---- */
        .navbar-main {
            background: rgba(8, 9, 15, 0.85);
            backdrop-filter: blur(22px);
            border-bottom: 1px solid rgba(0, 82, 255, 0.35);
            padding: 14px 0;
            position: sticky;
            top: 0;
            z-index: 1050;
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.7);
        }
        .navbar-brand-custom {
            font-family: var(--font-heading);
            font-weight: 700;
            font-size: 1.8rem;
            color: var(--text-white);
            text-decoration: none;
            letter-spacing: -0.3px;
            background: linear-gradient(135deg, #FFFFFF 0%, #CBD5E1 90%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .nav-link-custom {
            color: var(--text-silver);
            font-weight: 550;
            font-size: 1rem;
            margin: 0 6px;
            padding: 10px 18px;
            border-radius: 40px;
            text-decoration: none;
            transition: var(--transition-smooth);
            letter-spacing: 0.2px;
            background: transparent;
            border: 1px solid transparent;
        }
        .nav-link-custom:hover {
            color: var(--accent-cyan);
            background: rgba(0, 240, 255, 0.05);
            border-color: rgba(0, 240, 255, 0.4);
            box-shadow: 0 0 14px rgba(0, 240, 255, 0.25);
        }
        .nav-link-custom.active {
            background: rgba(0, 82, 255, 0.18);
            border-color: var(--accent-blue);
            color: var(--text-white);
            font-weight: 600;
            box-shadow: 0 0 20px rgba(0, 82, 255, 0.35);
        }
        .btn-electric {
            background: linear-gradient(135deg, #0052FF, #0040CC);
            border: none;
            color: white;
            font-weight: 650;
            padding: 10px 24px;
            border-radius: 40px;
            box-shadow: 0 0 22px rgba(0, 82, 255, 0.65);
            transition: 0.25s ease;
            letter-spacing: 0.4px;
            font-size: 0.95rem;
        }
        .btn-electric:hover {
            background: linear-gradient(135deg, #0066FF, #0052FF);
            box-shadow: 0 0 32px rgba(0, 130, 255, 0.9);
            transform: translateY(-1px);
            color: white;
        }
        .text-silver {
            color: var(--text-silver);
            cursor: pointer;
            font-weight: 500;
            transition: 0.2s;
        }
        .text-silver:hover {
            color: var(--accent-cyan);
        }

        /* ---- Mobile navigation shared fix ---- */
        @media (max-width: 768px) {
            .navbar-brand-custom {
                font-size: 1.4rem;
            }
            .navbar-main .d-md-flex {
                display: none !important;
            }
        }

        /* ---- Category Page Specific ---- */
        .hero-category {
            background: linear-gradient(135deg, #05080F 0%, #0E162A 100%);
            padding: 55px 0 60px;
            border-bottom: 1px solid rgba(0, 82, 255, 0.25);
            position: relative;
            overflow: hidden;
        }
        .hero-category::before {
            content: "";
            position: absolute;
            top: -30%;
            right: -10%;
            width: 650px;
            height: 650px;
            background: radial-gradient(circle, rgba(0, 82, 255, 0.12) 0%, transparent 70%);
            border-radius: 50%;
            z-index: 0;
        }
        .data-panel {
            background: rgba(12, 18, 34, 0.7);
            backdrop-filter: blur(20px);
            border: 1px solid rgba(0, 240, 255, 0.2);
            border-radius: var(--border-radius-lg);
            padding: 24px 28px;
            box-shadow: var(--shadow-neon);
            color: white;
        }
        .stat-badge {
            background: rgba(0, 240, 255, 0.08);
            border-left: 4px solid var(--accent-cyan);
            padding: 12px 16px;
            border-radius: 12px;
            margin-bottom: 14px;
            font-weight: 500;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .glass-card {
            background: var(--surface-glass);
            backdrop-filter: blur(18px);
            border: 1px solid var(--border-glass);
            border-radius: var(--border-radius-md);
            padding: 28px 24px;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
            transition: 0.3s ease;
        }
        .glass-card:hover {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 28px rgba(0, 240, 255, 0.35);
        }

        .feature-icon {
            font-size: 2.4rem;
            color: var(--accent-cyan);
            margin-bottom: 16px;
            filter: drop-shadow(0 0 10px rgba(0, 240, 255, 0.6));
        }

        .btn-cyan-outline {
            border: 2px solid var(--accent-cyan);
            background: transparent;
            color: var(--accent-cyan);
            font-weight: 650;
            padding: 14px 34px;
            border-radius: 50px;
            letter-spacing: 0.6px;
            transition: 0.25s;
            text-transform: uppercase;
            font-size: 0.95rem;
        }
        .btn-cyan-outline:hover {
            background: var(--accent-cyan);
            color: #08090F;
            box-shadow: 0 0 30px var(--accent-cyan);
        }

        .accordion-button-custom {
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid rgba(255, 255, 255, 0.08);
            color: white;
            font-weight: 600;
            border-radius: 14px !important;
            padding: 18px 22px;
        }

        .footer-site {
            background: #03050A;
            border-top: 1px solid rgba(0, 82, 255, 0.4);
            padding: 35px 0 25px;
            color: #A6ACAF;
            font-size: 0.95rem;
            backdrop-filter: blur(10px);
        }

        h1, h2, h3 {
            font-family: var(--font-heading);
            color: var(--text-white);
        }
        h2 {
            font-weight: 700;
            letter-spacing: -0.2px;
        }
        .text-cyan {
            color: var(--accent-cyan);
        }

        @media (max-width: 768px) {
            .glass-card {
                padding: 20px 18px;
            }
            .hero-category {
                padding: 35px 0 40px;
            }
        }