/* roulang page: index */
:root {
            --brand-primary: #00B894;
            --brand-primary-dark: #008f72;
            --brand-secondary: #0984E3;
            --brand-accent: #FF7675;
            --dark-titanium: #0F172A;
            --dark-navy: #0B132B;
            --text-heading: #1E293B;
            --text-body: #475569;
            --text-muted: #94A3B8;
            --bg-light-1: #F8FAFC;
            --bg-light-2: #EEF2F6;
            --card-radius: 14px;
            --card-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.08);
            --card-shadow-hover: 0 18px 36px -10px rgba(15, 23, 42, 0.16);
            --transition-base: all 0.25s ease;
        }

        body {
            font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-body);
            background-color: #FFFFFF;
            line-height: 1.75;
            -webkit-font-smoothing: antialiased;
        }

        h1, h2, h3, h4, h5, h6 {
            color: var(--text-heading);
            font-weight: 700;
            line-height: 1.3;
        }

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

        .section-padding {
            padding: 85px 0;
        }

        .section-header {
            margin-bottom: 50px;
        }

        .section-header h2 {
            font-size: 2.15rem;
            position: relative;
            margin-bottom: 16px;
        }

        .section-header p {
            max-width: 760px;
            margin: 0 auto;
            color: var(--text-body);
            font-size: 1.05rem;
        }

        .badge-brand {
            background: rgba(0, 184, 148, 0.12);
            color: var(--brand-primary-dark);
            font-weight: 600;
            padding: 6px 14px;
            border-radius: 30px;
            font-size: 0.85rem;
            display: inline-block;
            margin-bottom: 12px;
        }

        /* Topbar */
        .site-topbar {
            background-color: var(--dark-navy);
            color: #94A3B8;
            font-size: 0.825rem;
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        }
        .site-topbar a {
            color: #CBD5E1;
        }
        .site-topbar a:hover {
            color: var(--brand-primary);
        }

        /* Main Navbar */
        .site-navbar {
            background: #FFFFFF;
            box-shadow: 0 4px 20px rgba(15, 23, 42, 0.06);
            padding: 12px 0;
        }
        .navbar-brand {
            font-size: 1.45rem;
            font-weight: 800;
            color: var(--dark-titanium);
            letter-spacing: -0.5px;
        }
        .navbar-brand span {
            color: var(--brand-primary);
        }
        .nav-link {
            font-weight: 500;
            color: #334155;
            padding: 8px 16px !important;
            border-radius: 8px;
        }
        .nav-link:hover, .nav-link.active {
            color: var(--brand-primary-dark) !important;
            background: rgba(0, 184, 148, 0.06);
        }

        /* Mega Dropdown */
        .mega-dropdown-menu {
            width: 480px;
            border: none;
            border-radius: 12px;
            box-shadow: 0 20px 40px rgba(15, 23, 42, 0.15);
            padding: 20px;
            margin-top: 10px;
        }

        /* Buttons */
        .btn-brand-primary {
            background: linear-gradient(135deg, var(--brand-primary) 0%, #009E7E 100%);
            color: #FFFFFF;
            border: none;
            padding: 11px 26px;
            font-weight: 600;
            border-radius: 8px;
            box-shadow: 0 4px 14px rgba(0, 184, 148, 0.3);
        }
        .btn-brand-primary:hover {
            background: linear-gradient(135deg, #00A383 0%, #00886C 100%);
            color: #FFFFFF;
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(0, 184, 148, 0.4);
        }
        .btn-brand-outline {
            border: 2px solid rgba(255, 255, 255, 0.7);
            color: #FFFFFF;
            padding: 10px 24px;
            font-weight: 600;
            border-radius: 8px;
            background: transparent;
        }
        .btn-brand-outline:hover {
            background: #FFFFFF;
            color: var(--dark-titanium);
            border-color: #FFFFFF;
            transform: translateY(-2px);
        }

        /* Hero */
        .hero-banner {
            background: linear-gradient(rgba(11, 19, 43, 0.85), rgba(15, 23, 42, 0.92)), url('/assets/images/56a2489ead095dda.jpg') center center / cover no-repeat;
            min-height: 560px;
            display: flex;
            align-items: center;
            color: #FFFFFF;
        }
        .hero-banner h1 {
            color: #FFFFFF;
            font-size: 2.85rem;
            letter-spacing: -0.5px;
            line-height: 1.25;
        }
        .hero-video-box {
            position: relative;
            background: #000;
            border-radius: 16px;
            overflow: hidden;
            box-shadow: 0 20px 45px rgba(0, 0, 0, 0.4);
            border: 2px solid rgba(255, 255, 255, 0.1);
        }
        .hero-video-box img {
            width: 100%;
            height: 380px;
            object-fit: cover;
            opacity: 0.85;
        }
        .video-play-tag {
            position: absolute;
            bottom: 18px;
            left: 18px;
            right: 18px;
            background: rgba(15, 23, 42, 0.85);
            backdrop-filter: blur(8px);
            padding: 12px 16px;
            border-radius: 10px;
        }

        /* Metrics Bar */
        .metrics-bar {
            background: #FFFFFF;
            border-radius: var(--card-radius);
            box-shadow: var(--card-shadow);
            margin-top: -50px;
            position: relative;
            z-index: 10;
            border: 1px solid #E2E8F0;
        }
        .metric-card {
            padding: 24px 20px;
            border-right: 1px solid #F1F5F9;
        }
        .metric-card:last-child {
            border-right: none;
        }
        .metric-val {
            font-size: 2.25rem;
            font-weight: 800;
            color: var(--dark-titanium);
            line-height: 1;
            margin-bottom: 6px;
        }
        .metric-val span {
            color: var(--brand-primary);
            font-size: 1.4rem;
        }

        /* Feature Cards */
        .custom-card {
            background: #FFFFFF;
            border-radius: var(--card-radius);
            box-shadow: var(--card-shadow);
            border: 1px solid #F1F5F9;
            transition: var(--transition-base);
            height: 100%;
            overflow: hidden;
        }
        .custom-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--card-shadow-hover);
            border-color: #CBD5E1;
        }

        /* Dark Concept Section */
        .dark-concept-section {
            background-color: var(--dark-titanium);
            color: #E2E8F0;
        }
        .dark-concept-section h2, .dark-concept-section h3 {
            color: #FFFFFF;
        }
        .concept-item {
            border-left: 3px solid var(--brand-primary);
            padding-left: 18px;
            margin-bottom: 24px;
        }

        /* Timeline */
        .timeline-step {
            position: relative;
            padding: 24px;
            background: #FFFFFF;
            border-radius: var(--card-radius);
            border: 1px solid #E2E8F0;
            box-shadow: var(--card-shadow);
        }
        .timeline-badge {
            display: inline-block;
            background: var(--dark-titanium);
            color: #FFFFFF;
            font-size: 0.85rem;
            font-weight: 700;
            padding: 4px 10px;
            border-radius: 6px;
            margin-bottom: 12px;
        }

        /* Multi-end device card */
        .platform-chip {
            background: #F1F5F9;
            padding: 8px 14px;
            border-radius: 8px;
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--text-heading);
            display: inline-flex;
            align-items: center;
            gap: 6px;
            margin-right: 8px;
            margin-bottom: 8px;
        }

        /* FAQ Accordion */
        .accordion-button:not(.collapsed) {
            background-color: rgba(0, 184, 148, 0.08);
            color: var(--brand-primary-dark);
            box-shadow: none;
        }
        .accordion-item {
            border-radius: 10px !important;
            margin-bottom: 12px;
            border: 1px solid #E2E8F0;
            overflow: hidden;
        }

        /* Footer */
        .site-footer {
            background-color: var(--dark-navy);
            color: #94A3B8;
            font-size: 0.9rem;
            padding-top: 70px;
            padding-bottom: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
        }
        .site-footer h5 {
            color: #FFFFFF;
            font-size: 1.1rem;
            margin-bottom: 20px;
        }
        .site-footer ul li {
            margin-bottom: 10px;
        }
        .site-footer a {
            color: #94A3B8;
        }
        .site-footer a:hover {
            color: var(--brand-primary);
        }
        .footer-bottom {
            margin-top: 50px;
            padding-top: 25px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
            font-size: 0.825rem;
        }

        @media (max-width: 991.98px) {
            .hero-banner {
                padding: 60px 0;
            }
            .hero-banner h1 {
                font-size: 2.15rem;
            }
            .metric-card {
                border-right: none;
                border-bottom: 1px solid #F1F5F9;
            }
            .mega-dropdown-menu {
                width: 100%;
            }
        }