/* roulang page: index */
:root {
            --primary-blue: #4E6EF2;
            --primary-dark: #3A5CE4;
            --success-green: #00B578;
            --warning-orange: #FF9F0A;
            --error-red: #FA5151;
            --text-primary: #1F2329;
            --text-secondary: #86909C;
            --bg-light: #F5F6FA;
            --card-white: #FFFFFF;
            --border-light: #E8EBF0;
            --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.04);
            --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.06);
            --shadow-focus: 0 0 0 3px rgba(78, 110, 242, 0.2);
            --radius-card: 12px;
            --radius-btn: 999px;
            --radius-input: 8px;
            --spacing-xs: 8px;
            --spacing-sm: 16px;
            --spacing-md: 24px;
            --spacing-lg: 48px;
            --spacing-xl: 80px;
            --max-width: 1200px;
            --nav-height: 64px;
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-family);
            font-size: 16px;
            line-height: 1.6;
            color: var(--text-primary);
            background: var(--bg-light);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: color 200ms ease;
        }

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

        button,
        input {
            font-family: inherit;
            font-size: inherit;
            border: none;
            outline: none;
            background: transparent;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 var(--spacing-md);
        }

        /* 导航 */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            height: var(--nav-height);
            background: transparent;
            transition: background 300ms ease, box-shadow 300ms ease;
        }

        .header.scrolled {
            background: var(--card-white);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
        }

        .nav {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 100%;
            padding: 0 var(--spacing-md);
            max-width: var(--max-width);
            margin: 0 auto;
        }

        .logo {
            display: flex;
            align-items: center;
            font-size: 20px;
            font-weight: 700;
            color: var(--text-primary);
            gap: var(--spacing-xs);
        }

        .logo i {
            color: var(--primary-blue);
            font-size: 24px;
        }

        .logo span {
            font-size: 14px;
            font-weight: 400;
            color: var(--text-secondary);
            margin-left: 4px;
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 32px;
            list-style: none;
        }

        .nav-links a {
            font-size: 16px;
            color: var(--text-primary);
            position: relative;
            padding: 8px 0;
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--primary-blue);
            border-radius: 2px;
            transition: width 200ms ease;
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: var(--primary-blue);
        }

        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }

        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            background: none;
            border: none;
            padding: 4px;
        }

        .hamburger span {
            display: block;
            width: 24px;
            height: 2px;
            background: var(--text-primary);
            border-radius: 2px;
            transition: all 300ms ease;
        }

        @media (max-width:767px) {
            .nav-links {
                position: fixed;
                top: var(--nav-height);
                left: 0;
                width: 100%;
                background: var(--card-white);
                flex-direction: column;
                gap: 0;
                box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
                max-height: 0;
                overflow: hidden;
                transition: max-height 300ms ease;
                padding: 0 var(--spacing-md);
            }
            .nav-links.open {
                max-height: 500px;
                padding: var(--spacing-md) 0;
            }
            .nav-links a {
                padding: var(--spacing-sm) 0;
                display: block;
                font-size: 18px;
            }
            .hamburger {
                display: flex;
            }
            .container {
                padding: 0 16px;
            }
        }

        /* 首屏 Hero */
        .hero {
            padding-top: calc(var(--nav-height) + 60px);
            padding-bottom: var(--spacing-xl);
            background: var(--bg-light) url('/assets/images/backpic/back-1.webp') no-repeat center center;
            background-size: cover;
            position: relative;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(245, 246, 250, 0.85);
        }

        .hero-content {
            position: relative;
            display: flex;
            align-items: center;
            gap: 60px;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 var(--spacing-md);
        }

        .hero-text {
            flex: 1;
        }

        .hero-text h1 {
            font-size: 36px;
            font-weight: 700;
            line-height: 1.3;
            color: var(--text-primary);
            margin-bottom: var(--spacing-sm);
        }

        .hero-text h1 span {
            color: var(--primary-blue);
            background: rgba(78, 110, 242, 0.08);
            padding: 0 8px;
            border-radius: 4px;
        }

        .hero-subtitle {
            font-size: 18px;
            color: var(--text-secondary);
            margin-bottom: 32px;
            line-height: 1.6;
        }

        .hero-actions {
            display: flex;
            gap: var(--spacing-sm);
            flex-wrap: wrap;
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 14px 32px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            font-size: 16px;
            cursor: pointer;
            transition: all 200ms ease;
            border: 1.5px solid transparent;
        }

        .btn-primary {
            background: var(--primary-blue);
            color: #fff;
            border-color: var(--primary-blue);
        }

        .btn-primary:hover {
            background: var(--primary-dark);
            border-color: var(--primary-dark);
            transform: translateY(-1px);
        }

        .btn-secondary {
            background: transparent;
            color: var(--primary-blue);
            border-color: var(--primary-blue);
        }

        .btn-secondary:hover {
            background: rgba(78, 110, 242, 0.05);
        }

        .hero-dashboard {
            flex: 1;
            display: flex;
            flex-wrap: wrap;
            gap: var(--spacing-sm);
        }

        .stat-card {
            background: var(--card-white);
            border-radius: var(--radius-card);
            padding: var(--spacing-md);
            box-shadow: var(--shadow-card);
            flex: 1 1 130px;
            text-align: center;
        }

        .stat-number {
            font-size: 28px;
            font-weight: 700;
            color: var(--primary-blue);
            display: block;
            margin-bottom: 4px;
        }

        .stat-label {
            font-size: 12px;
            color: var(--text-secondary);
        }

        @media (max-width:1024px) {
            .hero-content {
                flex-direction: column;
                gap: 40px;
            }
            .hero-dashboard {
                width: 100%;
                justify-content: center;
            }
        }

        @media (max-width:767px) {
            .hero-text h1 {
                font-size: 30px;
            }
            .hero-subtitle {
                font-size: 16px;
            }
            .hero-dashboard {
                flex-direction: column;
            }
            .stat-card {
                flex: auto;
            }
        }

        /* 通用区块 */
        section {
            padding: var(--spacing-xl) 0;
        }

        .section-title {
            font-size: 28px;
            font-weight: 700;
            color: var(--text-primary);
            text-align: center;
            margin-bottom: 40px;
            line-height: 1.4;
        }

        .section-subtitle {
            text-align: center;
            color: var(--text-secondary);
            font-size: 16px;
            margin-bottom: 48px;
            margin-top: -24px;
        }

        /* 核心优势 */
        .advantages-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }

        .advantage-card {
            background: var(--card-white);
            border-radius: var(--radius-card);
            padding: var(--spacing-md);
            box-shadow: var(--shadow-card);
            text-align: center;
            transition: all 200ms ease;
        }

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

        .advantage-icon {
            font-size: 34px;
            color: var(--primary-blue);
            margin-bottom: var(--spacing-sm);
        }

        .advantage-card h3 {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: var(--spacing-xs);
            color: var(--text-primary);
        }

        .advantage-card p {
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.6;
        }

        /* 服务矩阵 */
        .services-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }

        .service-card {
            background: var(--card-white);
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-card);
            overflow: hidden;
            transition: all 200ms ease;
        }

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

        .service-img {
            height: 160px;
            background: #E8EBF0;
            display: flex;
            align-items: center;
            justify-content: center;
            overflow: hidden;
        }

        .service-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .service-body {
            padding: var(--spacing-md);
        }

        .service-body h3 {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: var(--spacing-xs);
        }

        .service-body p {
            font-size: 14px;
            color: var(--text-secondary);
        }

        /* 对比区 */
        .comparison-wrapper {
            display: flex;
            align-items: center;
            gap: var(--spacing-md);
            max-width: 900px;
            margin: 0 auto;
        }

        .vs-badge {
            font-size: 24px;
            font-weight: 700;
            color: var(--text-secondary);
            background: var(--card-white);
            border-radius: 50%;
            width: 60px;
            height: 60px;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: var(--shadow-card);
            flex-shrink: 0;
        }

        .compare-card {
            flex: 1;
            background: var(--card-white);
            border-radius: var(--radius-card);
            padding: var(--spacing-md);
            box-shadow: var(--shadow-card);
            list-style: none;
        }

        .compare-card.before {
            background: #FFF0F0;
        }

        .compare-card.after {
            background: #F0FFF6;
        }

        .compare-card h3 {
            font-size: 20px;
            margin-bottom: var(--spacing-sm);
            font-weight: 700;
        }

        .compare-card li {
            font-size: 14px;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .icon-red {
            color: var(--error-red);
        }
        .icon-green {
            color: var(--success-green);
        }
        .highlight-number {
            font-weight: 700;
            color: var(--primary-blue);
        }

        @media (max-width:767px) {
            .comparison-wrapper {
                flex-direction: column;
            }
            .vs-badge {
                margin: 12px 0;
            }
        }

        /* FAQ */
        .faq-list {
            max-width: 800px;
            margin: 0 auto;
        }

        .faq-item {
            background: var(--card-white);
            border-radius: var(--radius-card);
            padding: var(--spacing-md);
            box-shadow: var(--shadow-card);
            margin-bottom: var(--spacing-sm);
            cursor: pointer;
        }

        .faq-question {
            font-size: 16px;
            font-weight: 600;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .faq-icon {
            font-size: 18px;
            transition: transform 200ms ease;
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 300ms ease;
            font-size: 14px;
            color: var(--text-secondary);
            line-height: 1.6;
            margin-top: 0;
        }

        .faq-item.open .faq-answer {
            max-height: 200px;
            margin-top: 16px;
        }

        .faq-item.open .faq-icon {
            transform: rotate(45deg);
        }

        /* 表单 */
        .cta-form {
            background: var(--card-white);
            border-radius: var(--radius-card);
            padding: 40px;
            box-shadow: var(--shadow-card);
            max-width: 700px;
            margin: 0 auto;
            text-align: center;
        }

        .form-row {
            display: flex;
            gap: var(--spacing-sm);
            margin-bottom: var(--spacing-sm);
            flex-wrap: wrap;
        }

        .form-input {
            flex: 1;
            height: 48px;
            border: 1px solid var(--border-light);
            border-radius: var(--radius-input);
            padding: 0 var(--spacing-sm);
            font-size: 16px;
            transition: box-shadow 200ms, border-color 200ms;
            background: var(--card-white);
        }

        .form-input:focus {
            border-color: var(--primary-blue);
            box-shadow: var(--shadow-focus);
        }

        .btn-submit {
            background: var(--primary-blue);
            color: #fff;
            height: 48px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            padding: 0 40px;
            cursor: pointer;
            transition: background 200ms, transform 100ms;
        }

        .btn-submit:hover {
            background: var(--primary-dark);
        }
        .btn-submit:active {
            transform: scale(0.98);
        }

        .trust-text {
            font-size: 12px;
            color: var(--text-secondary);
            margin-top: var(--spacing-sm);
        }

        @media (max-width:767px) {
            .form-row {
                flex-direction: column;
            }
            .btn-submit {
                width: 100%;
            }
        }

        /* 页脚 */
        .footer {
            background: var(--card-white);
            padding: var(--spacing-lg) 0;
            border-top: 1px solid var(--border-light);
        }

        .footer-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 var(--spacing-md);
        }

        .footer-logo {
            font-size: 20px;
            font-weight: 700;
        }

        .footer-desc {
            font-size: 14px;
            color: var(--text-secondary);
            margin-top: 4px;
        }

        .footer-copy {
            font-size: 14px;
            color: var(--text-secondary);
        }

        @media (max-width:767px) {
            .footer-content {
                flex-direction: column;
                text-align: center;
                gap: 12px;
            }
            .advantages-grid,
            .services-grid {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width:1024px) and (min-width:768px) {
            .advantages-grid,
            .services-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }