/* roulang page: index */
:root {
            --primary: #1A56DB;
            --primary-light: #DBEAFE;
            --primary-dark: #1E40AF;
            --accent: #F59E0B;
            --accent-hover: #D97706;
            --dark: #0F172A;
            --gray-bg: #F8FAFC;
            --gray-card: #FFFFFF;
            --gray-light: #F1F5F9;
            --text-primary: #0F172A;
            --text-secondary: #475569;
            --text-muted: #64748B;
            --text-light: #94A3B8;
            --border-light: #E2E8F0;
            --success: #10B981;
            --danger: #EF4444;
            --radius-card: 12px;
            --radius-btn: 8px;
            --radius-input: 6px;
            --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.05);
            --shadow-card-hover: 0 4px 8px rgba(0,0,0,0.06), 0 8px 24px rgba(26,86,219,0.08);
            --transition: all 0.25s ease;
            --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
        }

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

        body {
            font-family: var(--font-stack);
            background-color: var(--gray-bg);
            color: var(--text-secondary);
            line-height: 1.7;
            font-size: 1rem;
            -webkit-font-smoothing: antialiased;
        }

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

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

        button, .button {
            cursor: pointer;
            font-family: inherit;
            border: none;
            outline: none;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }

        input, textarea {
            font-family: inherit;
            outline: none;
            transition: var(--transition);
        }

        h1, h2, h3, h4 {
            color: var(--text-primary);
            line-height: 1.3;
            margin-bottom: 0.5rem;
        }

        h1 {
            font-size: 2.8rem;
            font-weight: 700;
            letter-spacing: -0.02em;
        }

        h2 {
            font-size: 2rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
            position: relative;
            display: inline-block;
        }

        h2::after {
            content: '';
            position: absolute;
            bottom: -8px;
            left: 0;
            width: 40px;
            height: 4px;
            background-color: var(--accent);
            border-radius: 2px;
        }

        h3 {
            font-size: 1.25rem;
            font-weight: 600;
        }

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

        /* Top Info Bar */
        .top-bar {
            background: var(--dark);
            color: #CBD5E1;
            font-size: 0.8rem;
            height: 36px;
            display: flex;
            align-items: center;
        }
        .top-bar .container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
        }
        .top-bar-left span {
            margin-right: 12px;
        }
        .top-bar-left .divider {
            color: #475569;
            margin: 0 8px;
        }
        .top-bar-right a {
            color: #CBD5E1;
            margin-left: 16px;
            font-weight: 500;
        }
        .top-bar-right a:hover {
            color: var(--accent);
        }

        /* Main Navigation */
        .main-nav {
            background: #FFFFFF;
            height: 64px;
            border-bottom: 1px solid var(--border-light);
            position: sticky;
            top: 0;
            z-index: 50;
        }
        .main-nav .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 100%;
        }
        .logo-area {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--primary);
            text-decoration: none;
        }
        .logo-icon {
            width: 36px;
            height: 36px;
            background: var(--primary);
            clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 1.2rem;
        }
        .nav-links {
            display: flex;
            gap: 32px;
            align-items: center;
        }
        .nav-links a {
            color: var(--dark);
            font-weight: 500;
            padding: 8px 0;
            border-bottom: 3px solid transparent;
            font-size: 0.95rem;
        }
        .nav-links a:hover, .nav-links a.active {
            color: var(--primary);
            border-bottom-color: var(--accent);
        }
        .hamburger {
            display: none;
            background: none;
            font-size: 1.6rem;
            color: var(--dark);
        }
        .mobile-menu {
            display: none;
        }

        /* Hero */
        .hero {
            background: linear-gradient(135deg, #F8FAFC 0%, #EFF6FF 100%);
            padding: 60px 0;
        }
        .hero .grid-x {
            align-items: center;
        }
        .hero-content h1 {
            margin-bottom: 1rem;
        }
        .hero-subtitle {
            font-size: 1.2rem;
            color: var(--text-secondary);
            margin-bottom: 2rem;
        }
        .btn-group {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
        }
        .btn-primary {
            background: var(--accent);
            color: white;
            padding: 14px 28px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            font-size: 1rem;
            box-shadow: 0 2px 6px rgba(245,158,11,0.3);
        }
        .btn-primary:hover {
            background: var(--accent-hover);
            transform: translateY(-2px);
            box-shadow: 0 8px 16px rgba(245,158,11,0.35);
            color: white;
        }
        .btn-outline {
            border: 2px solid var(--primary);
            color: var(--primary);
            padding: 14px 28px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            background: transparent;
        }
        .btn-outline:hover {
            background: var(--primary);
            color: white;
            transform: translateY(-2px);
        }
        .hero-image img {
            border-radius: 16px;
            box-shadow: var(--shadow-card-hover);
        }

        /* Section Spacing */
        section {
            padding: 80px 0;
        }

        .section-header {
            margin-bottom: 48px;
        }

        /* Metrics Cards */
        .metrics-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
        }
        .metric-card {
            background: var(--gray-card);
            border-radius: var(--radius-card);
            padding: 28px 24px;
            box-shadow: var(--shadow-card);
            border-left: 4px solid var(--primary);
            display: flex;
            flex-direction: column;
            gap: 8px;
            transition: var(--transition);
        }
        .metric-card:hover {
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-2px);
        }
        .metric-label {
            font-size: 0.9rem;
            color: var(--text-muted);
            font-weight: 500;
        }
        .metric-value {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--primary);
            letter-spacing: -0.01em;
            font-variant-numeric: tabular-nums;
        }
        .metric-trend {
            font-size: 0.85rem;
            color: var(--success);
            display: flex;
            align-items: center;
            gap: 4px;
        }

        /* Service Cards */
        .services-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 28px;
        }
        .service-card {
            background: var(--gray-card);
            border-radius: var(--radius-card);
            padding: 32px 28px;
            box-shadow: var(--shadow-card);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            align-items: flex-start;
        }
        .service-card:hover {
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-4px);
        }
        .service-icon {
            width: 56px;
            height: 56px;
            background: var(--primary-light);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            color: var(--primary);
            font-size: 1.6rem;
        }
        .service-card p {
            font-size: 0.95rem;
            margin: 10px 0 16px;
        }
        .text-link {
            color: var(--primary);
            font-weight: 600;
            font-size: 0.9rem;
            display: inline-flex;
            align-items: center;
            gap: 6px;
            margin-top: auto;
        }
        .text-link i {
            transition: transform 0.2s;
        }
        .text-link:hover i {
            transform: translateX(4px);
        }

        /* Comparison */
        .comparison-grid {
            display: grid;
            grid-template-columns: 1fr auto 1fr;
            gap: 20px;
            align-items: start;
        }
        .compare-col {
            background: var(--gray-card);
            border-radius: var(--radius-card);
            padding: 32px;
            box-shadow: var(--shadow-card);
        }
        .compare-col.bad {
            background: #F9FAFB;
            border: 1px solid #E5E7EB;
        }
        .compare-col.good {
            background: #FFFFFF;
            border: 2px solid var(--primary-light);
            box-shadow: 0 8px 24px rgba(26,86,219,0.06);
        }
        .compare-title {
            font-size: 1.3rem;
            font-weight: 700;
            margin-bottom: 24px;
        }
        .compare-list {
            list-style: none;
        }
        .compare-list li {
            margin-bottom: 14px;
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 500;
        }
        .icon-fail {
            color: var(--danger);
        }
        .icon-success {
            color: var(--success);
        }
        .vs-badge {
            background: white;
            width: 56px;
            height: 56px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 800;
            color: var(--primary);
            box-shadow: 0 4px 12px rgba(0,0,0,0.08);
            font-size: 1.1rem;
            margin-top: 60px;
        }

        /* FAQ */
        .faq-list {
            max-width: 860px;
            margin: 0 auto;
        }
        .faq-item {
            border-bottom: 1px solid var(--border-light);
        }
        .faq-question {
            display: flex;
            align-items: baseline;
            gap: 16px;
            padding: 20px 0;
            cursor: pointer;
            font-weight: 600;
            color: var(--text-primary);
            transition: var(--transition);
            background: none;
            border: none;
            width: 100%;
            text-align: left;
            font-size: 1.05rem;
        }
        .faq-number {
            color: var(--accent);
            font-weight: 700;
            font-size: 1.2rem;
            min-width: 32px;
        }
        .faq-answer {
            padding: 0 0 20px 48px;
            display: none;
            color: var(--text-secondary);
        }
        .faq-item.active .faq-question {
            color: var(--primary);
        }
        .faq-item.active .faq-number {
            background: var(--primary);
            color: white;
            border-radius: 4px;
            padding: 2px 8px;
        }
        .faq-item.active .faq-answer {
            display: block;
            background: #F8FAFC;
            margin-bottom: 10px;
            border-radius: 0 0 12px 12px;
        }

        /* Contact Form */
        .contact-section {
            background-color: #F1F5F9;
            background-image: radial-gradient(#CBD5E1 1px, transparent 1px);
            background-size: 20px 20px;
        }
        .form-card {
            background: white;
            border-radius: var(--radius-card);
            padding: 40px;
            max-width: 600px;
            margin: 0 auto;
            box-shadow: var(--shadow-card);
        }
        .form-card input, .form-card textarea {
            width: 100%;
            padding: 14px 16px;
            border: 1px solid var(--border-light);
            border-radius: var(--radius-input);
            margin-bottom: 20px;
            font-size: 1rem;
        }
        .form-card input:focus, .form-card textarea:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(26,86,219,0.1);
        }
        .trust-badges {
            display: flex;
            gap: 24px;
            justify-content: center;
            margin-top: 24px;
            color: var(--text-muted);
            font-size: 0.85rem;
            flex-wrap: wrap;
        }
        .trust-badges i {
            margin-right: 6px;
            color: var(--success);
        }

        /* Footer */
        .footer {
            background: var(--dark);
            color: #94A3B8;
            padding: 60px 0 30px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
        }
        .footer h4 {
            color: white;
            font-size: 1.1rem;
            margin-bottom: 16px;
        }
        .footer a {
            color: #94A3B8;
            display: block;
            margin-bottom: 8px;
            font-size: 0.9rem;
        }
        .footer a:hover {
            color: var(--accent);
        }
        .footer-bottom {
            border-top: 1px solid #1E293B;
            margin-top: 40px;
            padding-top: 20px;
            text-align: center;
            font-size: 0.85rem;
        }

        /* Responsive */
        @media (max-width: 1024px) {
            .metrics-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .services-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .comparison-grid {
                grid-template-columns: 1fr;
            }
            .vs-badge {
                margin: 16px auto;
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }
            .nav-links {
                display: none;
            }
            .hamburger {
                display: block;
            }
            .mobile-menu {
                position: fixed;
                top: 64px;
                left: 0;
                width: 100%;
                background: var(--dark);
                flex-direction: column;
                padding: 24px;
                gap: 20px;
                z-index: 40;
            }
            .mobile-menu a {
                color: white;
                font-size: 1.2rem;
                border-bottom: 1px solid #1E293B;
                padding-bottom: 12px;
            }
            .mobile-menu.show {
                display: flex;
            }
            .hero .grid-x {
                flex-direction: column-reverse;
            }
            .hero-image {
                margin-bottom: 30px;
            }
            .services-grid {
                grid-template-columns: 1fr;
            }
            .metrics-grid {
                grid-template-columns: 1fr 1fr;
            }
            .footer-grid {
                grid-template-columns: 1fr;
            }
        }
        @media (max-width: 520px) {
            .metrics-grid {
                grid-template-columns: 1fr;
            }
            .btn-group {
                flex-direction: column;
            }
        }