/* roulang page: index */
:root {
      --primary: #2C3E6B;
      --primary-deep: #1e2a4a;
      --primary-light: rgba(44, 62, 107, 0.08);
      --accent: #D49B3B;
      --accent-light: rgba(212, 155, 59, 0.12);
      --gray-bg: #F8FAFC;
      --gray-border: #E5E7EB;
      --gray-text: #4B5563;
      --gray-weak: #6B7280;
      --dark-title: #111827;
      --dark-body: #1F2937;
      --white: #FFFFFF;
      --footer-bg: #111827;
      --footer-bar: #0F172A;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 24px;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-hover: 0 4px 16px rgba(0,0,0,0.06);
      --transition: 200ms ease;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: var(--dark-body);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input {
      font-family: inherit;
      font-size: inherit;
    }
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--white);
      z-index: 100;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow var(--transition), border-color var(--transition);
    }
    .navbar.scrolled {
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--gray-border);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 20px;
      color: var(--primary);
      letter-spacing: -0.2px;
    }
    .logo-icon {
      display: flex;
      gap: 3px;
      flex-direction: column;
      width: 20px;
      height: 18px;
      justify-content: space-between;
    }
    .logo-icon span {
      display: block;
      height: 4px;
      background: var(--primary);
      border-radius: 2px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--gray-text);
      font-size: 16px;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }
    .nav-links a:hover {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 10px 22px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      cursor: pointer;
      transition: background var(--transition);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-deep);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 10px 22px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      cursor: pointer;
      transition: background var(--transition), color var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-accent {
      background: var(--accent);
      color: var(--dark-title);
      border: none;
      padding: 12px 24px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      cursor: pointer;
    }
    .mobile-nav {
      display: none;
    }
    /* 区块通用 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 32px;
      font-weight: 600;
      line-height: 1.3;
      color: var(--dark-title);
      margin-bottom: 12px;
      letter-spacing: -0.3px;
    }
    .section-sub {
      font-size: 18px;
      color: var(--gray-weak);
      margin-bottom: 40px;
    }
    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: #F4F6F9;
      min-height: 560px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      background: #F3F4F6;
      border-radius: var(--radius-lg);
      overflow: hidden;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-right img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .decor-line {
      width: 40px;
      height: 3px;
      background: var(--primary);
      margin-bottom: 20px;
    }
    .hero h1 {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--dark-title);
      margin-bottom: 16px;
    }
    .hero p {
      font-size: 18px;
      color: var(--gray-text);
      margin-bottom: 28px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    /* 功能卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: white;
      border: 1px solid var(--gray-border);
      border-radius: var(--radius-md);
      padding: 24px;
      transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
    }
    .feature-card:hover {
      border-color: var(--primary);
      transform: translateY(-2px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      width: 32px;
      height: 32px;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .feature-card h4 {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .feature-card p {
      color: var(--gray-weak);
      font-size: 15px;
      margin-bottom: 12px;
    }
    .text-link {
      color: var(--primary);
      font-weight: 500;
      font-size: 15px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    /* 场景 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 50px;
      margin-bottom: 60px;
    }
    .scene-row.reverse {
      flex-direction: row-reverse;
    }
    .scene-img {
      flex: 1;
      background: #F3F4F6;
      border-radius: var(--radius-lg);
      overflow: hidden;
    }
    .scene-text {
      flex: 1;
    }
    .scene-text h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .check-list {
      list-style: none;
      margin-top: 16px;
    }
    .check-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 10px;
      color: var(--dark-body);
    }
    .check-icon {
      color: var(--accent);
      font-weight: bold;
    }
    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
    }
    .case-stripe {
      height: 4px;
      background: var(--primary);
    }
    .case-body {
      padding: 20px;
    }
    .case-body h4 {
      font-weight: 700;
      margin-bottom: 8px;
    }
    .case-stat {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
    }
    .data-bar {
      background: rgba(44,62,107,0.05);
      border-radius: var(--radius-md);
      padding: 24px;
      display: flex;
      justify-content: space-around;
      text-align: center;
      margin-top: 32px;
    }
    .data-item .number {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
    }
    /* 价格 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .price-card {
      background: white;
      border: 1px solid var(--gray-border);
      border-radius: var(--radius-lg);
      padding: 28px 24px;
      text-align: center;
    }
    .price-card.recommend {
      border-color: var(--primary);
      box-shadow: var(--shadow-sm);
    }
    .badge {
      background: var(--accent);
      color: white;
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 12px;
    }
    .price {
      font-size: 36px;
      font-weight: 700;
      color: var(--dark-title);
      margin: 12px 0;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--gray-border);
    }
    .faq-question {
      background: white;
      width: 100%;
      text-align: left;
      padding: 16px 20px;
      font-weight: 500;
      border: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 16px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.2s ease;
      background: #F9FAFB;
      padding: 0 20px;
      font-size: 15px;
      color: var(--gray-text);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 20px 16px;
    }
    /* CTA */
    .cta-dark {
      background: var(--footer-bg);
      color: white;
      text-align: center;
    }
    .cta-form {
      display: flex;
      justify-content: center;
      gap: 12px;
      flex-wrap: wrap;
      margin-top: 24px;
    }
    .cta-form input {
      padding: 12px 16px;
      border-radius: var(--radius-sm);
      border: 1px solid #D1D5DB;
      background: white;
      min-width: 240px;
    }
    .footer-bar {
      background: var(--footer-bar);
      color: #9CA3AF;
      font-size: 13px;
      padding: 16px 0;
      text-align: center;
    }
    /* 移动端底部导航 */
    @media (max-width: 768px) {
      .navbar {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        height: 64px;
        background: white;
        box-shadow: 0 -2px 8px rgba(0,0,0,0.04);
        border-top: 1px solid var(--gray-border);
        justify-content: space-around;
        align-items: center;
        z-index: 100;
        border-radius: 24px 24px 0 0;
      }
      .mobile-nav a {
        font-size: 13px;
        color: var(--gray-text);
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 2px;
      }
      .mobile-cta {
        background: var(--primary);
        color: white;
        padding: 8px 16px;
        border-radius: 24px;
        font-weight: 600;
      }
      .hero-grid {
        flex-direction: column;
      }
      .features-grid, .cases-grid, .pricing-grid {
        grid-template-columns: 1fr;
      }
      .scene-row, .scene-row.reverse {
        flex-direction: column;
      }
      section {
        padding: 60px 0;
      }
      .hero h1 {
        font-size: 32px;
      }
    }