/* roulang page: index */
/* ----- 设计变量 & 重置 ----- */
    :root {
      --primary: #4E6EF2;
      --primary-hover: #3A5BE0;
      --primary-light: #EEF1FD;
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
      --bg: #F5F6FA;
      --card-bg: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --text-disabled: #B0B8C2;
      --border-light: #E5E8EF;
      --border-input: #D0D5E0;
      --shadow-card: 0 2px 12px rgba(31, 35, 41, 0.06);
      --shadow-hover: 0 4px 20px rgba(78, 110, 242, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-pill: 50px;
      --max-width: 1200px;
      --header-height: 64px;
      --transition: 200ms ease-out;
    }

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

    body {
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

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

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ----- 导航 (sticky, 白底) ----- */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 1px 8px rgba(31, 35, 41, 0.04);
      height: var(--header-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0, 0, 0, 0.02);
    }

    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .logo span {
      color: var(--primary);
      font-weight: 800;
    }

    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      padding: 4px 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: 28px;
      color: var(--text-primary);
      cursor: pointer;
      line-height: 1;
    }

    /* 移动端导航 */
    @media (max-width: 767px) {
      .nav-links {
        position: fixed;
        bottom: 20px;
        left: 50%;
        transform: translateX(-50%);
        background: white;
        box-shadow: 0 8px 24px rgba(0,0,0,0.12);
        border-radius: 40px;
        padding: 8px 20px;
        gap: 16px;
        backdrop-filter: blur(8px);
        background: rgba(255,255,255,0.9);
        z-index: 55;
        display: flex;
      }
      .nav-links a {
        font-size: 13px;
        padding: 6px 10px;
        border-bottom: none;
        color: var(--text-secondary);
      }
      .header .container {
        justify-content: center;
      }
      .menu-toggle {
        display: none;
      }
      .header {
        height: 60px;
      }
    }

    /* ----- 通用板块样式 ----- */
    .section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 30px;
      font-weight: 600;
      letter-spacing: -0.3px;
      margin-bottom: 16px;
      color: var(--text-primary);
    }
    .section-sub {
      color: var(--text-secondary);
      font-size: 16px;
      margin-bottom: 40px;
    }

    /* ----- 按钮系统 ----- */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 500;
      border-radius: var(--radius-btn);
      transition: all var(--transition);
      cursor: pointer;
      border: 1.5px solid transparent;
      padding: 10px 24px;
      font-size: 15px;
      background: transparent;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      border-color: var(--primary-hover);
      box-shadow: 0 4px 14px rgba(78, 110, 242, 0.25);
      transform: translateY(-1px);
    }
    .btn-outline {
      border-color: var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-pill {
      border-radius: var(--radius-pill);
      padding: 14px 32px;
      font-weight: 600;
      min-width: 160px;
      font-size: 16px;
    }

    /* ----- 卡片系统 ----- */
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      padding: 24px;
      transition: all var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }

    /* ----- Hero ----- */
    .hero {
      padding: 60px 0 80px;
      display: flex;
      align-items: center;
      gap: 40px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 400px;
    }
    .hero h1 {
      font-size: 42px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.6px;
      margin-bottom: 18px;
    }
    .hero .highlight {
      color: var(--primary);
    }
    .hero p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 28px;
      max-width: 500px;
    }
    .hero-visual {
      flex: 1 1 400px;
      position: relative;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 28px;
      min-height: 320px;
      box-shadow: 0 12px 28px rgba(0,0,0,0.06);
      overflow: hidden;
    }
    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(78,110,242,0.08) 0%, rgba(245,246,250,0.2) 100%);
    }

    /* ----- 数据看板 ----- */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      background: linear-gradient(180deg, #F0F3FF 0%, #F5F6FA 100%);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      margin-top: 20px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 44px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
    }
    .stat-label {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 8px;
    }

    /* ----- 服务矩阵 左图标右文字 ----- */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .service-card {
      display: flex;
      gap: 18px;
      align-items: flex-start;
    }
    .service-icon {
      font-size: 28px;
      color: var(--primary);
      background: var(--primary-light);
      border-radius: 12px;
      padding: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 56px;
      height: 56px;
    }
    .service-text h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 6px;
    }
    .service-text p {
      color: var(--text-secondary);
      font-size: 15px;
      line-height: 1.5;
    }

    /* ----- 对比表格 ----- */
    .compare-block {
      background: #F8F9FC;
      border-radius: var(--radius-card);
      padding: 28px;
      display: flex;
      flex-wrap: wrap;
      gap: 30px;
    }
    .compare-col {
      flex: 1 1 240px;
    }
    .compare-title {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 20px;
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
      font-size: 16px;
    }
    .check-green {
      color: var(--green);
      font-weight: 600;
    }
    .cross-gray {
      color: var(--text-disabled);
    }
    .badge {
      background: var(--primary-light);
      color: var(--primary);
      font-weight: 600;
      padding: 2px 10px;
      border-radius: 20px;
      font-size: 13px;
      margin-left: 8px;
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 14px 0;
      cursor: pointer;
      transition: background 0.2s;
    }
    .faq-question {
      font-weight: 500;
      font-size: 16px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.25s ease-out;
      color: var(--text-secondary);
      font-size: 14px;
      line-height: 1.6;
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--primary);
    }

    /* ----- 表单 ----- */
    .contact-card {
      background: linear-gradient(120deg, #F0F4FF 0%, #FFFFFF 100%);
      border-radius: 24px;
      padding: 48px 32px;
      text-align: center;
      max-width: 680px;
      margin: 0 auto;
    }
    .input-group {
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin: 28px 0 20px;
    }
    input, textarea {
      border: 1.5px solid var(--border-input);
      border-radius: var(--radius-btn);
      padding: 12px 16px;
      font-size: 15px;
      background: white;
      outline: none;
      transition: border var(--transition), box-shadow var(--transition);
    }
    input:focus, textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78,110,242,0.2);
    }
    .privacy-note {
      font-size: 13px;
      color: var(--text-disabled);
      margin-top: 12px;
    }

    /* ----- 页脚 ----- */
    .footer {
      background: #1F2329;
      color: #B0B8C2;
      padding: 48px 0 32px;
      font-size: 14px;
    }
    .footer-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 30px;
    }
    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: white;
    }

    /* ----- 响应式调整 ----- */
    @media (max-width: 1023px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 767px) {
      .hero {
        flex-direction: column;
      }
      .hero h1 {
        font-size: 34px;
      }
      .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: 16px;
      }
      .compare-block {
        flex-direction: column;
      }
      .section {
        padding: 56px 0;
      }
      .container {
        padding: 0 16px;
      }
    }