/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-hover: #1449B0;
      --primary-light: #EBF2FF;
      --accent: #F85C3C;
      --accent-hover: #D94A2E;
      --deep-title: #0B1E3C;
      --text-primary: #1A1F36;
      --text-body: #4A5568;
      --text-muted: #718096;
      --bg-page: #FAFBFD;
      --bg-card: #FFFFFF;
      --bg-section: #F4F7FC;
      --bg-faq: #F8FAFD;
      --border-light: #EDF2F7;
      --border-medium: #CBD5E0;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(26,95,220,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', sans-serif;
      --font-mono: 'Inter', 'SF Mono', 'Courier New', monospace;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.6;
      font-size: 16px;
      padding-top: 64px;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .section-padding {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      .section-padding {
        padding: 60px 0;
      }
      body {
        padding-top: 60px;
      }
    }
    h1, h2, h3, h4 {
      font-family: var(--font-sans);
    }
    h1 {
      font-size: 36px;
      line-height: 48px;
      font-weight: 700;
      color: var(--deep-title);
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 28px;
      line-height: 38px;
      font-weight: 600;
      color: var(--deep-title);
      text-align: center;
      margin-bottom: 20px;
      position: relative;
      display: flex;
      flex-direction: column;
      align-items: center;
    }
    h2::after {
      content: '';
      display: block;
      width: 40px;
      height: 2px;
      background-color: var(--primary);
      margin-top: 8px;
      border-radius: 1px;
    }
    h3 {
      font-size: 20px;
      line-height: 28px;
      font-weight: 600;
      color: var(--text-primary);
    }
    .text-body {
      color: var(--text-body);
      font-size: 16px;
      line-height: 26px;
    }
    .text-muted {
      color: var(--text-muted);
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input {
      font-family: inherit;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: #FFFFFF;
      border-bottom: 1px solid #EDF2F7;
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      font-weight: 700;
      font-size: 20px;
      color: var(--deep-title);
      letter-spacing: 1px;
    }
    .logo-icon {
      margin-right: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      color: white;
      font-size: 18px;
      font-weight: 600;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--text-primary);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        max-width: 280px;
        height: 100vh;
        background: white;
        flex-direction: column;
        padding: 80px 24px 30px;
        box-shadow: -4px 0 20px rgba(0,0,0,0.08);
        transition: right 0.3s ease;
        gap: 20px;
      }
      .nav-links.open {
        right: 0;
      }
      .menu-toggle {
        display: block;
        z-index: 110;
      }
    }
    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all var(--transition);
      cursor: pointer;
      border: 1.5px solid transparent;
      text-align: center;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(26,95,220,0.2);
    }
    .btn-outline {
      background: white;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      border-color: var(--accent);
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(248,92,60,0.25);
    }
    /* Hero */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      margin-bottom: 16px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 24px;
      border: 1px solid var(--border-light);
    }
    .mock-chart {
      display: flex;
      flex-direction: column;
      gap: 18px;
    }
    .chart-bar {
      height: 12px;
      background: #E2E8F0;
      border-radius: 6px;
      position: relative;
      overflow: hidden;
    }
    .chart-fill {
      height: 100%;
      background: var(--primary);
      border-radius: 6px;
      width: 0%;
    }
    .chart-row {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .chart-label {
      width: 60px;
      font-size: 14px;
      color: var(--text-muted);
    }
    .chart-value {
      font-weight: 600;
      color: var(--deep-title);
      margin-left: 8px;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      h1 {
        font-size: 28px;
        line-height: 38px;
      }
      h2 {
        font-size: 22px;
        line-height: 32px;
      }
    }
    /* 数据看板 */
    .dashboard-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 28px 20px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      text-align: center;
      transition: all var(--transition);
    }
    .stat-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      font-family: var(--font-mono);
      margin-bottom: 8px;
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 15px;
    }
    @media (max-width: 768px) {
      .dashboard-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    /* 服务网格 2x3 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: all var(--transition);
      text-align: left;
    }
    .service-card:hover {
      box-shadow: var(--shadow-hover);
      border-color: var(--border-medium);
    }
    .service-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 16px;
      transition: transform 0.2s;
    }
    .service-card:hover .service-icon {
      transform: translateY(-4px);
    }
    .service-title {
      margin-bottom: 8px;
    }
    @media (max-width: 1024px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 对比区 */
    .compare-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      position: relative;
    }
    .compare-col {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid var(--border-light);
    }
    .compare-title {
      font-weight: 600;
      font-size: 18px;
      margin-bottom: 20px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .compare-list {
      list-style: none;
    }
    .compare-list li {
      margin-bottom: 14px;
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 16px;
    }
    .negative li {
      color: #A0AEC0;
    }
    .positive li {
      color: var(--text-primary);
    }
    .icon-neg {
      color: #CBD5E0;
      font-weight: 700;
    }
    .icon-pos {
      color: var(--primary);
      font-weight: 700;
    }
    @media (max-width: 768px) {
      .compare-wrapper {
        grid-template-columns: 1fr;
      }
    }
    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      position: relative;
    }
    .step {
      flex: 1;
      text-align: center;
      position: relative;
      padding: 0 12px;
    }
    .step-circle {
      width: 60px;
      height: 60px;
      background: white;
      border: 2px solid var(--primary);
      border-radius: 50%;
      margin: 0 auto 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      color: var(--primary);
      transition: 0.2s;
    }
    .step-title {
      font-weight: 600;
      margin-bottom: 6px;
    }
    .step-desc {
      font-size: 14px;
      color: var(--text-muted);
    }
    .process-steps::before {
      content: '';
      position: absolute;
      top: 30px;
      left: 10%;
      right: 10%;
      height: 2px;
      border-top: 2px dashed #CBD5E0;
      z-index: 0;
    }
    .step {
      z-index: 1;
    }
    @media (max-width: 768px) {
      .process-steps {
        flex-direction: column;
        gap: 32px;
      }
      .process-steps::before {
        display: none;
      }
    }
    /* FAQ */
    .faq-item {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
      transition: background 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: var(--bg-faq);
      color: var(--text-body);
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 0 20px 20px;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--text-muted);
    }
    /* CTA */
    .cta-box {
      background: #F0F4FF;
      border-radius: 24px;
      padding: 64px 24px;
      text-align: center;
    }
    .cta-form {
      display: flex;
      max-width: 500px;
      margin: 28px auto 0;
      gap: 0;
    }
    .cta-input {
      flex: 1;
      height: 48px;
      border: 1px solid var(--border-medium);
      border-right: none;
      border-radius: 8px 0 0 8px;
      padding: 0 16px;
      font-size: 16px;
      outline: none;
    }
    .cta-input:focus {
      border-color: var(--primary);
    }
    .cta-btn {
      height: 48px;
      padding: 0 28px;
      background: var(--accent);
      color: white;
      border: none;
      border-radius: 0 8px 8px 0;
      font-weight: 600;
      cursor: pointer;
      transition: background 0.2s;
    }
    .cta-btn:hover {
      background: var(--accent-hover);
    }
    @media (max-width: 520px) {
      .cta-form {
        flex-direction: column;
        gap: 12px;
      }
      .cta-input, .cta-btn {
        border-radius: 8px;
        width: 100%;
        border-right: 1px solid var(--border-medium);
      }
    }
    /* 页脚 */
    .footer {
      background: #0B1E3C;
      color: #CBD5E0;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
    }
    .footer-col h4 {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .footer-col a {
      display: block;
      color: #CBD5E0;
      margin-bottom: 10px;
      font-size: 14px;
      transition: color 0.2s;
    }
    .footer-col a:hover {
      color: white;
    }
    .copyright {
      background: #081830;
      text-align: center;
      padding: 16px;
      color: #718096;
      margin-top: 40px;
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    .backimg-placeholder {
      background-color: #EDF2F7;
      border-radius: 8px;
    }