/* roulang page: index */
:root {
            --primary-deep: #0B1A3A;
            --primary-dark: #0F2447;
            --bg-gradient-start: #0A0F1E;
            --bg-gradient-end: #111B30;
            --accent-cyan: #00E5FF;
            --accent-amber: #FFB347;
            --text-primary: rgba(255, 255, 255, 0.9);
            --text-secondary: rgba(255, 255, 255, 0.7);
            --text-muted: rgba(255, 255, 255, 0.6);
            --border-subtle: rgba(255, 255, 255, 0.08);
            --border-light: rgba(255, 255, 255, 0.25);
            --glass-bg: rgba(255, 255, 255, 0.03);
            --glass-border: rgba(255, 255, 255, 0.08);
            --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.06) inset;
            --card-hover-shadow: 0 12px 40px rgba(0, 0, 0, 0.6), 0 0 20px rgba(0, 229, 255, 0.15), 0 0 0 1px rgba(255, 255, 255, 0.1) inset;
            --radius-lg: 20px;
            --radius-md: 16px;
            --radius-sm: 30px;
            --font-heading: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            --font-body: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            --sidebar-width: 76px;
        }

        * {
            box-sizing: border-box;
        }

        body {
            font-family: var(--font-body);
            background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
            color: var(--text-primary);
            margin: 0;
            padding: 0;
            min-height: 100vh;
            line-height: 1.6;
            display: flex;
            flex-direction: row;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: color 0.2s ease;
        }

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

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

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

        h1,
        h2,
        h3,
        h4,
        h5,
        h6 {
            font-family: var(--font-heading);
            font-weight: 700;
            line-height: 1.3;
            margin-top: 0;
            color: var(--text-primary);
        }

        h1 {
            font-size: 3.2rem;
            letter-spacing: -0.5px;
        }

        h2 {
            font-size: 2.2rem;
            margin-bottom: 1.5rem;
        }

        h3 {
            font-size: 1.2rem;
        }

        p {
            color: var(--text-secondary);
            margin-bottom: 1rem;
        }

        .text-muted {
            color: var(--text-muted) !important;
        }

        .text-cyan {
            color: var(--accent-cyan) !important;
        }

        .text-amber {
            color: var(--accent-amber) !important;
        }

        .bg-glass {
            background: var(--glass-bg);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border: 1px solid var(--glass-border);
        }

        .btn-primary-custom {
            background: linear-gradient(135deg, var(--accent-cyan) 0%, #00b8d4 100%);
            border: none;
            color: var(--primary-deep);
            font-weight: 600;
            border-radius: var(--radius-sm);
            padding: 0.8rem 2.2rem;
            font-size: 1rem;
            letter-spacing: 0.3px;
            box-shadow: 0 0 18px rgba(0, 229, 255, 0.5);
            transition: all 0.25s ease;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            cursor: pointer;
        }

        .btn-primary-custom:hover {
            box-shadow: 0 0 28px rgba(0, 229, 255, 0.8);
            transform: scale(1.03);
            color: var(--primary-deep);
        }

        .btn-outline-custom {
            background: transparent;
            border: 1px solid var(--border-light);
            color: white;
            font-weight: 500;
            border-radius: var(--radius-sm);
            padding: 0.8rem 2.2rem;
            font-size: 1rem;
            transition: all 0.25s ease;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            cursor: pointer;
        }

        .btn-outline-custom:hover {
            border-color: var(--accent-cyan);
            background: rgba(0, 229, 255, 0.05);
            color: var(--accent-cyan);
        }

        .glass-card {
            background: var(--glass-bg);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-md);
            padding: 2rem;
            box-shadow: var(--card-shadow);
            transition: all 0.3s ease;
            height: 100%;
        }

        .glass-card:hover {
            box-shadow: var(--card-hover-shadow);
            transform: translateY(-4px);
        }

        .badge-pill {
            background: rgba(0, 229, 255, 0.15);
            color: var(--accent-cyan);
            font-size: 0.75rem;
            font-weight: 500;
            padding: 0.3rem 0.9rem;
            border-radius: 50px;
            display: inline-block;
        }

        /* App Shell Sidebar */
        .app-sidebar {
            position: fixed;
            top: 0;
            left: 0;
            width: var(--sidebar-width);
            height: 100vh;
            background: #080D1A;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: 1.5rem 0;
            z-index: 1050;
            border-right: none;
            box-shadow: 2px 0 15px rgba(0, 0, 0, 0.5);
            transition: transform 0.3s ease;
        }

        .sidebar-logo {
            font-weight: 700;
            font-size: 1.4rem;
            color: var(--accent-cyan);
            writing-mode: vertical-rl;
            text-orientation: upright;
            letter-spacing: 2px;
            margin-bottom: 2rem;
            cursor: pointer;
        }

        .sidebar-nav {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 1.8rem;
            flex: 1;
            justify-content: flex-start;
            margin-top: 1rem;
        }

        .sidebar-nav a {
            color: rgba(255, 255, 255, 0.7);
            font-size: 1.3rem;
            position: relative;
            padding: 0.5rem 0;
            transition: 0.2s;
            display: flex;
            flex-direction: column;
            align-items: center;
            text-decoration: none;
        }

        .sidebar-nav a span {
            font-size: 0.65rem;
            margin-top: 4px;
            opacity: 0.8;
            font-weight: 400;
        }

        .sidebar-nav a.active,
        .sidebar-nav a:hover {
            color: var(--accent-cyan);
        }

        .sidebar-nav a.active::before {
            content: '';
            position: absolute;
            left: -12px;
            top: 0;
            bottom: 0;
            width: 3px;
            background: var(--accent-cyan);
            border-radius: 0 4px 4px 0;
        }

        .sidebar-social {
            display: flex;
            flex-direction: column;
            gap: 1.2rem;
            color: rgba(255, 255, 255, 0.5);
            font-size: 1.1rem;
            margin-bottom: 0.5rem;
        }

        .sidebar-social i {
            cursor: pointer;
            transition: color 0.2s;
        }

        .sidebar-social i:hover {
            color: var(--accent-cyan);
        }

        /* Main Content */
        .main-content {
            margin-left: var(--sidebar-width);
            width: calc(100% - var(--sidebar-width));
            min-height: 100vh;
        }

        /* Hero Section */
        #hero {
            display: flex;
            align-items: center;
            min-height: 90vh;
            padding: 2rem 3rem;
            background: radial-gradient(circle at 30% 40%, rgba(0, 229, 255, 0.08) 0%, transparent 50%);
        }

        .hero-left h1 {
            font-weight: 700;
            margin-bottom: 1.2rem;
            letter-spacing: -0.3px;
        }

        .hero-left .lead {
            font-size: 1.15rem;
            color: var(--text-secondary);
            max-width: 480px;
            margin-bottom: 2rem;
        }

        .hero-right .glass-card {
            padding: 1rem;
            border-radius: 24px;
            transform: rotate(1deg);
            transition: transform 0.3s ease;
        }

        .hero-right .glass-card:hover {
            transform: rotate(0deg) translateY(-5px);
        }

        .hero-right img {
            border-radius: 16px;
            width: 100%;
            height: auto;
            object-fit: cover;
        }

        /* Sections */
        section {
            padding: 5rem 2rem;
        }

        .section-title {
            margin-bottom: 2.5rem;
            position: relative;
            display: inline-block;
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: -8px;
            left: 0;
            width: 50px;
            height: 3px;
            background: var(--accent-cyan);
            border-radius: 3px;
        }

        /* Advantages Grid */
        .advantage-icon {
            font-size: 2.4rem;
            color: var(--accent-cyan);
            margin-bottom: 1.2rem;
        }

        /* Products waterfall */
        .product-card {
            border-radius: var(--radius-lg);
            overflow: hidden;
            background: rgba(255, 255, 255, 0.02);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.05);
            transition: all 0.3s ease;
            height: fit-content;
            margin-bottom: 1.5rem;
        }

        .product-card:hover {
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5), 0 0 20px rgba(0, 229, 255, 0.1);
            transform: translateY(-5px);
        }

        .product-img {
            height: 200px;
            background-size: cover;
            background-position: center;
        }

        .product-info {
            padding: 1.5rem;
        }

        /* Compare Table */
        .compare-table {
            border-radius: var(--radius-lg);
            overflow: hidden;
            background: rgba(255, 255, 255, 0.02);
            backdrop-filter: blur(15px);
            border: 1px solid rgba(255, 255, 255, 0.06);
        }

        .compare-header {
            background: rgba(255, 255, 255, 0.05);
        }

        .compare-col-highlight {
            background: rgba(0, 229, 255, 0.05);
            border-top: 3px solid var(--accent-cyan);
        }

        /* FAQ Accordion */
        .faq-item {
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
            transition: 0.3s;
        }

        .faq-question {
            padding: 1.2rem 0;
            font-weight: 500;
            cursor: pointer;
            display: flex;
            align-items: center;
            position: relative;
            font-size: 1.1rem;
        }

        .faq-question::before {
            content: '';
            width: 4px;
            height: 20px;
            background: var(--accent-cyan);
            margin-right: 1rem;
            border-radius: 2px;
            transition: 0.2s;
        }

        .faq-answer {
            padding: 0 0 1.5rem 2rem;
            color: var(--text-muted);
            font-size: 0.95rem;
            line-height: 1.7;
        }

        /* Contact Form */
        .form-control-custom {
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid rgba(255, 255, 255, 0.1);
            border-radius: 10px;
            color: white;
            padding: 0.8rem 1rem;
            transition: 0.25s;
        }

        .form-control-custom:focus {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 10px rgba(0, 229, 255, 0.3);
            background: rgba(255, 255, 255, 0.06);
            outline: none;
            color: white;
        }

        /* Footer */
        footer {
            color: rgba(255, 255, 255, 0.35);
            font-size: 0.85rem;
            text-align: center;
            padding: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.05);
        }

        /* Mobile adjustments */
        @media (max-width: 992px) {
            .app-sidebar {
                transform: translateX(-100%);
                width: 260px;
                align-items: flex-start;
                padding-left: 1.5rem;
            }

            .app-sidebar.mobile-open {
                transform: translateX(0);
            }

            .sidebar-logo {
                writing-mode: horizontal-tb;
                text-orientation: mixed;
                margin-bottom: 1.5rem;
                font-size: 1.6rem;
            }

            .sidebar-nav {
                align-items: flex-start;
                gap: 1.2rem;
            }

            .sidebar-nav a {
                flex-direction: row;
                gap: 10px;
                font-size: 1.1rem;
            }

            .sidebar-nav a span {
                font-size: 0.9rem;
                margin-top: 0;
            }

            .sidebar-social {
                flex-direction: row;
                gap: 1.5rem;
            }

            .main-content {
                margin-left: 0;
                width: 100%;
            }

            .mobile-nav-toggle {
                display: flex;
                position: fixed;
                top: 15px;
                left: 15px;
                z-index: 1100;
                background: rgba(8, 13, 26, 0.9);
                backdrop-filter: blur(10px);
                border-radius: 8px;
                padding: 0.6rem;
                color: white;
                font-size: 1.5rem;
                cursor: pointer;
                border: 1px solid rgba(255, 255, 255, 0.15);
            }

            #hero {
                flex-direction: column;
                padding: 6rem 1.5rem 3rem;
                text-align: center;
            }

            .hero-left h1 {
                font-size: 2.5rem;
            }
            section {
                padding: 3rem 1.5rem;
            }
        }

        @media (min-width: 993px) {
            .mobile-nav-toggle {
                display: none;
            }
        }

        @media (max-width: 576px) {
            h1 {
                font-size: 2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
        }