/* roulang page: index */
:root {
            --primary: #0F62FE;
            --primary-dark: #001D6C;
            --primary-light: #4589ff;
            --secondary: #00B39E;
            --dark-surface: #0B132B;
            --dark-card: #152244;
            --light-bg: #F4F7FB;
            --white: #FFFFFF;
            --text-main: #0A1128;
            --text-muted: #475569;
            --text-light: #94A3B8;
            --border-color: rgba(15, 98, 254, 0.12);
            --border-radius-lg: 24px;
            --border-radius-md: 16px;
            --border-radius-pill: 9999px;
            --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.04);
            --shadow-md: 0 10px 30px -10px rgba(15, 98, 254, 0.12), 0 4px 12px rgba(0, 0, 0, 0.03);
            --shadow-lg: 0 20px 40px -15px rgba(15, 98, 254, 0.18);
            --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
        }

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

        html {
            scroll-behavior: smooth;
            font-family: var(--font-sans);
            background-color: var(--light-bg);
            color: var(--text-main);
            line-height: 1.75;
        }

        body {
            overflow-x: hidden;
            width: 100%;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: all 0.3s ease;
        }

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

        .container {
            width: 100%;
            max-width: 1280px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 24px;
            padding-right: 24px;
        }

        /* 顶部导航 */
        .top-bar {
            background-color: var(--dark-surface);
            color: var(--text-light);
            font-size: 13px;
            padding: 8px 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        }
        .top-bar-inner {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .top-tags span {
            margin-right: 18px;
            color: rgba(255, 255, 255, 0.85);
        }
        .top-tags span i {
            color: var(--secondary);
            font-style: normal;
            margin-right: 4px;
        }

        header.main-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border-color);
            transition: all 0.3s ease;
        }
        .nav-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 76px;
        }
        .logo-box {
            display: flex;
            align-items: center;
            gap: 12px;
            font-size: 22px;
            font-weight: 800;
            color: var(--primary-dark);
            letter-spacing: -0.5px;
        }
        .logo-box .badge {
            font-size: 11px;
            padding: 3px 8px;
            background: rgba(15, 98, 254, 0.1);
            color: var(--primary);
            border-radius: var(--border-radius-pill);
            font-weight: 600;
        }
        .nav-links {
            display: flex;
            gap: 28px;
            list-style: none;
        }
        .nav-links a {
            font-size: 15px;
            font-weight: 600;
            color: var(--text-muted);
            position: relative;
            padding: 6px 0;
        }
        .nav-links a:hover, .nav-links a.active {
            color: var(--primary);
        }
        .nav-links a.active::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 2px;
            background: var(--primary);
            border-radius: 2px;
        }

        /* 按钮体系 */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 12px 28px;
            border-radius: var(--border-radius-pill);
            font-size: 15px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            border: 1px solid transparent;
            gap: 8px;
        }
        .btn-primary {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            color: var(--white);
            box-shadow: 0 6px 20px -4px rgba(15, 98, 254, 0.45);
        }
        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 24px -4px rgba(15, 98, 254, 0.6);
        }
        .btn-outline {
            background: transparent;
            color: var(--primary);
            border-color: var(--primary);
        }
        .btn-outline:hover {
            background: rgba(15, 98, 254, 0.06);
        }
        .btn-secondary {
            background: var(--secondary);
            color: var(--white);
        }
        .btn-secondary:hover {
            background: #009987;
        }

        /* 徽章体系 */
        .badge-pill {
            display: inline-flex;
            align-items: center;
            padding: 4px 12px;
            border-radius: var(--border-radius-pill);
            font-size: 12px;
            font-weight: 700;
            background: rgba(15, 98, 254, 0.08);
            color: var(--primary);
            border: 1px solid rgba(15, 98, 254, 0.15);
        }

        /* 板块公用 */
        section {
            padding: 80px 0;
            position: relative;
        }
        .section-header {
            margin-bottom: 50px;
        }
        .section-header.center {
            text-align: center;
            max-width: 760px;
            margin-left: auto;
            margin-right: auto;
        }
        .section-header h2 {
            font-size: 32px;
            font-weight: 800;
            color: var(--text-main);
            margin-top: 10px;
            margin-bottom: 14px;
            line-height: 1.3;
        }
        .section-header p {
            font-size: 16px;
            color: var(--text-muted);
            line-height: 1.7;
        }

        /* 1. Hero 价值主张 */
        #hero {
            padding: 60px 0 90px;
            background: radial-gradient(circle at 80% 20%, rgba(0, 179, 158, 0.08) 0%, transparent 50%),
                        radial-gradient(circle at 20% 80%, rgba(15, 98, 254, 0.06) 0%, transparent 60%),
                        var(--light-bg);
            border-bottom: 1px solid var(--border-color);
        }
        .hero-grid {
            display: grid;
            grid-template-columns: 1.15fr 0.85fr;
            gap: 48px;
            align-items: center;
        }
        .hero-content h1 {
            font-size: 44px;
            line-height: 1.25;
            font-weight: 900;
            color: var(--text-main);
            margin-bottom: 20px;
        }
        .hero-content h1 span {
            background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .hero-desc {
            font-size: 16px;
            color: var(--text-muted);
            margin-bottom: 32px;
            line-height: 1.8;
        }
        .hero-actions {
            display: flex;
            gap: 16px;
            margin-bottom: 36px;
        }
        .hero-kpis {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 16px;
            padding-top: 24px;
            border-top: 1px solid rgba(15, 98, 254, 0.12);
        }
        .hero-kpi-num {
            font-size: 26px;
            font-weight: 800;
            color: var(--primary-dark);
        }
        .hero-kpi-label {
            font-size: 13px;
            color: var(--text-muted);
        }
        .hero-dashboard-panel {
            background: var(--white);
            border-radius: var(--border-radius-lg);
            padding: 24px;
            box-shadow: var(--shadow-lg);
            border: 1px solid var(--border-color);
            position: relative;
        }
        .panel-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-bottom: 1px solid #edf2f7;
            padding-bottom: 14px;
            margin-bottom: 18px;
        }
        .panel-title {
            font-size: 15px;
            font-weight: 700;
            color: var(--text-main);
        }
        .ranking-item {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 12px 14px;
            margin-bottom: 10px;
            border-radius: var(--border-radius-md);
            background: #F8FAFC;
            transition: all 0.2s;
        }
        .ranking-item:hover {
            background: #EFF6FF;
            transform: translateX(4px);
        }
        .ranking-rank {
            width: 24px;
            height: 24px;
            border-radius: 50%;
            background: #E2E8F0;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 12px;
            font-weight: 700;
            color: var(--text-muted);
            margin-right: 12px;
        }
        .ranking-item:first-child .ranking-rank {
            background: #FEF08A;
            color: #854D0E;
        }
        .ranking-info {
            flex: 1;
        }
        .ranking-name {
            font-size: 14px;
            font-weight: 600;
            color: var(--text-main);
        }
        .ranking-val {
            font-size: 13px;
            font-weight: 700;
            color: var(--primary);
        }

        /* 2. 硬件架构与教学体系综述 */
        #overview {
            background: var(--white);
        }
        .overview-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 48px;
            align-items: center;
        }
        .overview-img-wrap {
            border-radius: var(--border-radius-lg);
            overflow: hidden;
            box-shadow: var(--shadow-md);
            position: relative;
            border: 1px solid var(--border-color);
        }
        .overview-specs {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 16px;
            margin-top: 24px;
        }
        .spec-box {
            padding: 16px;
            background: var(--light-bg);
            border-radius: var(--border-radius-md);
            border-left: 4px solid var(--primary);
        }
        .spec-title {
            font-size: 13px;
            color: var(--text-muted);
        }
        .spec-val {
            font-size: 16px;
            font-weight: 700;
            color: var(--text-main);
            margin-top: 4px;
        }

        /* 3. 功能矩阵 */
        #features {
            background: var(--light-bg);
        }
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .feature-card {
            background: var(--white);
            border-radius: var(--border-radius-lg);
            padding: 32px 28px;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-color);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            position: relative;
        }
        .feature-card:hover {
            transform: translateY(-6px);
            box-shadow: var(--shadow-lg);
            border-color: rgba(15, 98, 254, 0.3);
        }
        .feature-badge-top {
            position: absolute;
            top: 24px;
            right: 24px;
        }
        .feature-icon-bar {
            width: 48px;
            height: 48px;
            border-radius: 14px;
            background: rgba(15, 98, 254, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            color: var(--primary);
            margin-bottom: 20px;
        }
        .feature-card h3 {
            font-size: 19px;
            font-weight: 700;
            margin-bottom: 12px;
            color: var(--text-main);
        }
        .feature-card p {
            font-size: 14px;
            color: var(--text-muted);
            line-height: 1.7;
        }

        /* 4. 产品矩阵 */
        #products {
            background: var(--white);
        }
        .product-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 28px;
        }
        .product-card {
            border-radius: var(--border-radius-lg);
            border: 1px solid var(--border-color);
            background: var(--white);
            overflow: hidden;
            box-shadow: var(--shadow-sm);
            display: flex;
            flex-direction: column;
            transition: all 0.3s;
        }
        .product-card:hover {
            box-shadow: var(--shadow-lg);
            border-color: var(--primary);
        }
        .product-img-box {
            position: relative;
            height: 220px;
            overflow: hidden;
            background: #000;
        }
        .product-img-box img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .product-card:hover .product-img-box img {
            transform: scale(1.05);
        }
        .product-body {
            padding: 24px;
            flex: 1;
            display: flex;
            flex-direction: column;
        }
        .product-body h3 {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: 8px;
        }
        .product-tags {
            display: flex;
            flex-wrap: wrap;
            gap: 6px;
            margin-bottom: 14px;
        }
        .product-tag {
            font-size: 11px;
            padding: 3px 8px;
            background: #F1F5F9;
            color: #475569;
            border-radius: 4px;
        }
        .product-desc {
            font-size: 14px;
            color: var(--text-muted);
            margin-bottom: 20px;
            line-height: 1.6;
            flex: 1;
        }
        .product-footer {
            padding-top: 16px;
            border-top: 1px solid #F1F5F9;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        /* 5. 多维教学场景 */
        #scenarios {
            background: var(--light-bg);
        }
        .scenario-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }
        .scenario-item {
            background: var(--white);
            border-radius: var(--border-radius-lg);
            padding: 24px;
            border: 1px solid var(--border-color);
            transition: all 0.3s;
        }
        .scenario-item:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
        }
        .scenario-num {
            font-size: 32px;
            font-weight: 900;
            color: rgba(15, 98, 254, 0.15);
            line-height: 1;
            margin-bottom: 12px;
        }
        .scenario-item h3 {
            font-size: 18px;
            font-weight: 700;
            margin-bottom: 10px;
        }
        .scenario-item p {
            font-size: 13.5px;
            color: var(--text-muted);
            line-height: 1.6;
        }

        /* 6. 课程体系 */
        #curriculum {
            background: var(--white);
        }
        .curriculum-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            align-items: center;
        }
        .curriculum-timeline {
            display: flex;
            flex-direction: column;
            gap: 18px;
        }
        .timeline-step {
            display: flex;
            gap: 16px;
            padding: 18px 20px;
            background: var(--light-bg);
            border-radius: var(--border-radius-md);
            border-left: 4px solid var(--secondary);
            transition: all 0.2s;
        }
        .timeline-step:hover {
            background: #EBF5F5;
        }
        .step-index {
            font-size: 18px;
            font-weight: 800;
            color: var(--secondary);
            min-width: 32px;
        }
        .step-content h4 {
            font-size: 16px;
            font-weight: 700;
            margin-bottom: 4px;
        }
        .step-content p {
            font-size: 13.5px;
            color: var(--text-muted);
            line-height: 1.6;
        }

        /* 7. 深色实证与科研 */
        #dark-case {
            background: var(--dark-surface);
            color: var(--white);
            border-radius: 36px;
            margin: 40px 24px;
            padding: 70px 48px;
        }
        #dark-case .section-header h2 {
            color: var(--white);
        }
        #dark-case .section-header p {
            color: var(--text-light);
        }
        .dark-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 36px;
        }
        .dark-card {
            background: var(--dark-card);
            border-radius: var(--border-radius-lg);
            padding: 32px;
            border: 1px solid rgba(255, 255, 255, 0.08);
        }
        .dark-card h3 {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: 12px;
            color: #38BDF8;
        }
        .dark-card p {
            font-size: 14.5px;
            color: #CBD5E1;
            line-height: 1.7;
            margin-bottom: 18px;
        }
        .dark-metrics {
            display: flex;
            gap: 24px;
            padding-top: 14px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }
        .dark-metric-item span {
            font-size: 12px;
            color: #94A3B8;
        }
        .dark-metric-item strong {
            display: block;
            font-size: 20px;
            color: var(--secondary);
        }

        /* 8. 量化数据统计条 */
        #metrics {
            padding: 40px 0;
            background: linear-gradient(135deg, rgba(15, 98, 254, 0.04) 0%, rgba(0, 179, 158, 0.06) 100%);
        }
        .metrics-banner {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            text-align: center;
        }
        .metric-banner-item {
            padding: 20px;
            background: var(--white);
            border-radius: var(--border-radius-lg);
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-color);
        }
        .metric-banner-num {
            font-size: 38px;
            font-weight: 900;
            color: var(--primary);
            line-height: 1.1;
            margin-bottom: 6px;
        }
        .metric-banner-title {
            font-size: 14px;
            font-weight: 600;
            color: var(--text-muted);
        }

        /* 9. 标杆教学故事 */
        #stories {
            background: var(--white);
        }
        .story-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 32px;
        }
        .story-card {
            background: var(--light-bg);
            border-radius: var(--border-radius-lg);
            overflow: hidden;
            border: 1px solid var(--border-color);
            display: flex;
            flex-direction: column;
        }
        .story-img-wrap {
            height: 200px;
            overflow: hidden;
        }
        .story-img-wrap img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .story-body {
            padding: 28px;
            flex: 1;
        }
        .story-body h3 {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: 10px;
        }
        .story-body p {
            font-size: 14px;
            color: var(--text-muted);
            line-height: 1.7;
            margin-bottom: 16px;
        }

        /* 10. 用户口碑墙 */
        #testimonials {
            background: var(--light-bg);
        }
        .testimonial-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .testimonial-card {
            background: var(--white);
            border-radius: var(--border-radius-lg);
            padding: 28px;
            border: 1px solid var(--border-color);
            box-shadow: var(--shadow-sm);
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }
        .quote-text {
            font-size: 14.5px;
            color: var(--text-main);
            line-height: 1.75;
            margin-bottom: 20px;
            font-style: italic;
        }
        .user-meta {
            display: flex;
            align-items: center;
            gap: 12px;
            border-top: 1px solid #F1F5F9;
            padding-top: 16px;
        }
        .user-avatar {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: #E2E8F0;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            color: var(--primary);
        }
        .user-name {
            font-size: 15px;
            font-weight: 700;
        }
        .user-role {
            font-size: 12px;
            color: var(--text-muted);
        }

        /* 11. 前沿资讯 */
        #insights {
            background: var(--white);
        }
        .insight-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .insight-card {
            border: 1px solid var(--border-color);
            border-radius: var(--border-radius-lg);
            overflow: hidden;
            background: var(--white);
            transition: all 0.3s;
        }
        .insight-card:hover {
            box-shadow: var(--shadow-md);
            transform: translateY(-4px);
        }
        .insight-img {
            height: 160px;
            overflow: hidden;
        }
        .insight-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .insight-body {
            padding: 20px;
        }
        .insight-date {
            font-size: 12px;
            color: var(--text-light);
            margin-bottom: 6px;
        }
        .insight-body h3 {
            font-size: 17px;
            font-weight: 700;
            margin-bottom: 10px;
            line-height: 1.4;
        }
        .insight-body p {
            font-size: 13.5px;
            color: var(--text-muted);
            line-height: 1.6;
            margin-bottom: 14px;
        }

        /* 12. 常见问题手风琴 */
        #faq {
            background: var(--light-bg);
        }
        .faq-accordion {
            max-width: 860px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 16px;
        }
        .faq-item {
            background: var(--white);
            border-radius: var(--border-radius-md);
            border: 1px solid var(--border-color);
            overflow: hidden;
        }
        .faq-question {
            padding: 20px 24px;
            font-size: 16px;
            font-weight: 700;
            color: var(--text-main);
            display: flex;
            justify-content: space-between;
            align-items: center;
            cursor: pointer;
            user-select: none;
        }
        .faq-answer {
            padding: 0 24px 20px;
            font-size: 14.5px;
            color: var(--text-muted);
            line-height: 1.7;
            display: none;
        }
        .faq-item.active .faq-answer {
            display: block;
        }
        .faq-item.active .faq-icon {
            transform: rotate(180deg);
        }
        .faq-icon {
            transition: transform 0.3s;
            font-size: 12px;
            color: var(--primary);
        }

        /* 转化收口区 */
        .cta-banner {
            background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
            border-radius: 32px;
            padding: 60px 48px;
            color: var(--white);
            text-align: center;
            margin-bottom: 80px;
            box-shadow: var(--shadow-lg);
        }
        .cta-banner h2 {
            font-size: 34px;
            font-weight: 800;
            margin-bottom: 16px;
        }
        .cta-banner p {
            font-size: 16px;
            max-width: 680px;
            margin: 0 auto 36px;
            color: rgba(255, 255, 255, 0.85);
        }
        .cta-form {
            display: flex;
            justify-content: center;
            gap: 12px;
            max-width: 560px;
            margin: 0 auto;
        }
        .cta-input {
            flex: 1;
            padding: 14px 20px;
            border-radius: var(--border-radius-pill);
            border: none;
            font-size: 15px;
            outline: none;
        }

        /* 页脚 */
        footer.main-footer {
            background: var(--dark-surface);
            color: #94A3B8;
            padding: 70px 0 30px;
            font-size: 14px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
            gap: 40px;
            margin-bottom: 50px;
        }
        .footer-brand h3 {
            color: var(--white);
            font-size: 20px;
            font-weight: 800;
            margin-bottom: 14px;
        }
        .footer-col h4 {
            color: var(--white);
            font-size: 15px;
            font-weight: 700;
            margin-bottom: 18px;
        }
        .footer-links {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        .footer-links a:hover {
            color: var(--white);
        }
        .footer-bottom {
            padding-top: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
            text-align: center;
            font-size: 13px;
        }

        /* 响应式断点 */
        @media (max-width: 1024px) {
            .hero-grid, .overview-grid, .curriculum-grid, .dark-grid, .story-grid {
                grid-template-columns: 1fr;
            }
            .feature-grid, .product-grid, .testimonial-grid, .insight-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .scenario-grid, .metrics-banner {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 768px) {
            .nav-links, .top-bar {
                display: none;
            }
            .feature-grid, .product-grid, .scenario-grid, .testimonial-grid, .insight-grid, .metrics-banner {
                grid-template-columns: 1fr;
            }
            .hero-content h1 {
                font-size: 32px;
            }
            .section-header h2 {
                font-size: 26px;
            }
            #dark-case {
                margin: 20px 12px;
                padding: 40px 20px;
                border-radius: 20px;
            }
            .cta-form {
                flex-direction: column;
            }
            .cta-banner {
                padding: 40px 20px;
                border-radius: 20px;
            }
            .footer-grid {
                grid-template-columns: 1fr;
            }
        }