/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #4E6EF2;
      --primary-hover: #3A5BE0;
      --primary-soft: rgba(78, 110, 242, 0.08);
      --primary-soft-hover: rgba(78, 110, 242, 0.12);
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --bg-page: #F5F6FA;
      --bg-white: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.02);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
      --max-width: 1200px;
      --padding-section: 80px 24px;
      --transition: 200ms ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-family);
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.5;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
    }
    h1, h2, h3 {
      font-weight: 600;
      line-height: 1.3;
    }
    /* 按钮组件 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 16px;
      box-shadow: 0 2px 8px rgba(78,110,242,0.2);
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(78,110,242,0.3);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background-color: var(--primary-soft);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 16px;
    }
    .btn-secondary:hover {
      background-color: var(--primary-soft-hover);
    }
    .btn-lg {
      padding: 16px 36px;
      font-size: 18px;
    }
    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
      z-index: 100;
      transition: var(--transition);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      height: 70px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      color: var(--text-primary);
    }
    .logo img {
      height: 32px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-primary);
      transition: color var(--transition);
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-cta {
      margin-left: 8px;
    }
    .hamburger {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--text-primary);
      cursor: pointer;
    }
    /* 板块通用 */
    section {
      padding: var(--padding-section);
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      text-align: center;
      margin-bottom: 16px;
      color: var(--text-primary);
    }
    .section-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 640px;
      margin: 0 auto 48px;
    }
    /* Hero */
    .hero {
      background: var(--bg-white);
      padding-top: 120px;
      padding-bottom: 80px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      margin-bottom: 20px;
      line-height: 1.2;
    }
    .hero-content p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      text-align: center;
    }
    .hero-image img {
      max-height: 380px;
      width: auto;
    }
    /* 卡片网格 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 24px;
      margin-top: 32px;
    }
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .card-icon {
      font-size: 32px;
      margin-bottom: 20px;
      color: var(--primary);
    }
    .card h3 {
      font-size: 20px;
      margin-bottom: 12px;
    }
    .card p {
      font-size: 15px;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    /* 痛点卡片特殊色调 */
    .pain-card .card-icon {
      color: #E65C5C;
    }
    /* 解决方案交错布局 */
    .solution-alt {
      display: flex;
      flex-direction: column;
      gap: 80px;
      margin-top: 40px;
    }
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-text h3 {
      font-size: 26px;
      margin-bottom: 16px;
    }
    .solution-text p {
      font-size: 16px;
      color: var(--text-secondary);
      line-height: 1.7;
    }
    .solution-img {
      flex: 1;
      text-align: center;
    }
    .solution-img img {
      max-height: 260px;
      border-radius: var(--radius-card);
    }
    /* 成果数据卡 */
    .metric-card {
      text-align: center;
    }
    .metric-number {
      font-size: 42px;
      font-weight: 700;
      color: var(--success);
      margin-bottom: 8px;
    }
    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 32px;
    }
    .testimonial-card {
      background: var(--bg-white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    .stars {
      color: var(--warning);
      margin-bottom: 16px;
    }
    .testimonial-text {
      font-style: italic;
      color: var(--text-primary);
      margin-bottom: 24px;
      font-size: 15px;
    }
    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .author-avatar {
      width: 44px;
      height: 44px;
      background: #E0E5FF;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      color: var(--primary);
    }
    .author-info strong {
      display: block;
      font-size: 16px;
    }
    .author-info span {
      font-size: 14px;
      color: var(--text-secondary);
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 40px auto 0;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .faq-item {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 20px 24px;
      box-shadow: var(--shadow-sm);
      cursor: pointer;
      transition: var(--transition);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 16px;
      line-height: 1.6;
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }
    .faq-icon {
      transition: transform 0.2s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    /* 终局 CTA */
    .cta-section {
      background: var(--primary);
      text-align: center;
      padding: 80px 24px;
    }
    .cta-card {
      max-width: 700px;
      margin: 0 auto;
      color: white;
    }
    .cta-card h2 {
      font-size: 36px;
      margin-bottom: 16px;
    }
    .cta-card p {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 32px;
    }
    .btn-cta-white {
      background: white;
      color: var(--primary);
      padding: 16px 42px;
      font-weight: 600;
      border-radius: var(--radius-btn);
    }
    .btn-cta-white:hover {
      background: #f0f2ff;
    }
    /* 页脚 */
    .main-footer {
      background: #1F2329;
      color: #86909C;
      padding: 60px 24px 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      max-width: var(--max-width);
      margin: 0 auto 40px;
    }
    .footer-col h4 {
      color: white;
      margin-bottom: 20px;
      font-size: 16px;
    }
    .footer-col a {
      display: block;
      color: #86909C;
      margin-bottom: 12px;
      font-size: 14px;
    }
    .footer-bottom {
      text-align: center;
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 24px;
      font-size: 14px;
    }
    /* 响应式 */
    @media (max-width: 992px) {
      .hero-grid, .solution-row, .solution-row.reverse {
        flex-direction: column;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 36px;
      }
      .testimonial-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: var(--shadow-sm);
        gap: 20px;
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .section-title {
        font-size: 28px;
      }
      .hero-content h1 {
        font-size: 32px;
      }
      .card-grid {
        grid-template-columns: 1fr;
      }
    }
    @media (max-width: 576px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }