/* roulang page: index */
/* ----- 全局设计变量 ----- */
    :root {
      --primary: #2B4EFF;
      --primary-soft: rgba(43, 78, 255, 0.08);
      --accent-gold: #F5A623;
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
      --bg: #F7F8FC;
      --white: #FFFFFF;
      --text-dark: #1A1C23;
      --text-secondary: #6B7280;
      --border-light: #E5E7EB;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04), 0 1px 4px rgba(0,0,0,0.02);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.03);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --transition: 200ms cubic-bezier(0.2, 0.0, 0, 1.0);
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background: var(--bg);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ----- 导航 ----- */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
    }
    .header.scrolled {
      background: rgba(255,255,255,0.95);
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-weight: 700;
      font-size: 24px;
      color: var(--text-dark);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
      text-decoration: none;
    }
    .logo span {
      color: var(--primary);
      font-weight: 800;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 16px;
      transition: color var(--transition);
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      text-decoration: none;
      display: inline-block;
      line-height: 1.2;
      box-shadow: 0 2px 8px rgba(43,78,255,0.18);
    }
    .btn-primary:hover {
      background: #1E3FDF;
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(43,78,255,0.28);
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 1px solid var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: all var(--transition);
      text-decoration: none;
      display: inline-block;
      line-height: 1.2;
    }
    .btn-secondary:hover {
      background: var(--primary-soft);
      border-color: var(--primary);
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text-dark);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
      .mobile-menu {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        box-shadow: 0 20px 30px rgba(0,0,0,0.05);
        z-index: 49;
      }
      .mobile-menu.open {
        display: flex;
      }
      .mobile-menu a {
        font-size: 18px;
        font-weight: 500;
        color: var(--text-dark);
        text-decoration: none;
      }
      .mobile-menu .btn-primary {
        width: 100%;
        text-align: center;
      }
    }

    /* ----- 板块通用 ----- */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 64px 0;
      }
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--text-dark);
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 600px;
    }
    .center-text {
      text-align: center;
      margin-left: auto;
      margin-right: auto;
    }

    /* ----- Hero ----- */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 64px;
      min-height: 90vh;
      padding-top: 80px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: var(--text-dark);
    }
    .hero-left h1 em {
      color: var(--primary);
      font-style: normal;
    }
    .hero-left p {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      flex: 1;
      position: relative;
      height: 400px;
      background: radial-gradient(circle at 30% 40%, rgba(43,78,255,0.08), transparent 60%);
      border-radius: var(--radius-lg);
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-right img {
      max-width: 100%;
      height: auto;
      border-radius: var(--radius-lg);
      object-fit: cover;
    }
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero-left h1 {
        font-size: 38px;
      }
      .hero-right {
        width: 100%;
        height: 300px;
      }
    }
    @media (max-width: 768px) {
      .hero-left h1 {
        font-size: 32px;
      }
    }

    /* ----- 数据看板 ----- */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 48px;
    }
    .data-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      transition: box-shadow var(--transition), transform var(--transition);
      text-align: center;
    }
    .data-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .data-number {
      font-size: 42px;
      font-weight: 700;
      color: var(--accent-gold);
      line-height: 1.2;
      margin-bottom: 8px;
    }
    .data-label {
      font-size: 14px;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .data-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .data-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 服务矩阵（非对称网格）----- */
    .service-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
      margin-top: 48px;
    }
    .service-main {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-card);
      border-left: 4px solid var(--primary);
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .service-side {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-card);
      border-left: 4px solid var(--primary);
      transition: transform var(--transition), box-shadow var(--transition);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .service-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .service-title {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 8px;
    }
    .service-desc {
      font-size: 16px;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
      .service-main {
        padding: 28px;
      }
    }

    /* ----- 结果对比 ----- */
    .compare-wrapper {
      display: flex;
      align-items: center;
      gap: 24px;
      margin-top: 48px;
    }
    .compare-card {
      flex: 1;
      padding: 32px;
      border-radius: var(--radius-lg);
      background: #F3F4F6;
      color: var(--text-secondary);
    }
    .compare-card.im {
      background: var(--white);
      border: 1px solid var(--primary);
      color: var(--text-dark);
    }
    .vs-badge {
      background: var(--white);
      border-radius: 50%;
      width: 56px;
      height: 56px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--primary);
      box-shadow: var(--shadow-card);
      font-size: 18px;
      flex-shrink: 0;
    }
    .compare-list {
      list-style: none;
      margin-top: 16px;
    }
    .compare-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .green-dot {
      color: var(--green);
      font-weight: 600;
    }
    @media (max-width: 768px) {
      .compare-wrapper {
        flex-direction: column;
      }
      .vs-badge {
        margin: 8px 0;
      }
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-list {
      margin-top: 40px;
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      align-items: center;
      gap: 12px;
      color: var(--text-dark);
    }
    .faq-q {
      color: var(--primary);
      font-weight: 700;
    }
    .faq-answer {
      font-size: 16px;
      color: var(--text-secondary);
      margin-top: 12px;
      display: none;
      padding-left: 32px;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-arrow {
      margin-left: auto;
      transition: transform 0.2s;
    }
    .faq-item.open .faq-arrow {
      transform: rotate(180deg);
    }

    /* ----- 联系表单 ----- */
    .contact-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 48px;
      display: flex;
      gap: 48px;
      box-shadow: var(--shadow-card);
      margin-top: 40px;
    }
    .contact-left {
      flex: 1;
    }
    .contact-right {
      flex: 1;
    }
    .input-group {
      margin-bottom: 20px;
    }
    .input-group input,
    .input-group textarea {
      width: 100%;
      border: none;
      border-bottom: 1px solid var(--border-light);
      padding: 12px 0;
      font-size: 16px;
      background: transparent;
      outline: none;
      transition: border-color var(--transition);
      font-family: var(--font-sans);
    }
    .input-group input:focus,
    .input-group textarea:focus {
      border-bottom-color: var(--primary);
    }
    @media (max-width: 768px) {
      .contact-card {
        flex-direction: column;
        padding: 28px;
      }
    }

    /* ----- 页脚 ----- */
    .footer {
      background: #1A1C23;
      color: #9CA3AF;
      padding: 32px 0;
      font-size: 14px;
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .footer-logo {
      font-weight: 700;
      font-size: 20px;
      color: white;
    }
    .footer-links a {
      color: #9CA3AF;
      text-decoration: none;
      margin-left: 24px;
    }
    @media (max-width: 768px) {
      .footer-content {
        flex-direction: column;
        gap: 16px;
      }
    }

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