/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #1A5F7A;
      --primary-dark: #0F3B4C;
      --primary-light: #E8F4F8;
      --accent-gold: #D4A853;
      --bg-light: #F7FAFC;
      --text-body: #4A5568;
      --text-muted: #718096;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition-smooth: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      margin: 0;
      padding: 0;
      background-color: #FFFFFF;
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    /* 自定义容器宽度 */
    .container-custom {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      z-index: 50;
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s ease;
    }

    .navbar.scrolled {
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    }

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

    .logo-text {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary-dark);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      gap: 40px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      padding-bottom: 6px;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
      white-space: nowrap;
    }

    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    /* 汉堡菜单按钮 */
    .hamburger {
      display: none;
      flex-direction: column;
      justify-content: space-between;
      width: 24px;
      height: 18px;
      background: transparent;
      border: none;
      padding: 0;
      cursor: pointer;
    }

    .hamburger span {
      display: block;
      width: 100%;
      height: 2px;
      background-color: var(--primary-dark);
      transition: transform 0.3s ease, opacity 0.2s;
    }

    /* 移动端全屏菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: #FFFFFF;
      z-index: 60;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      transform: translateY(-100%);
      transition: transform 0.35s ease;
    }

    .mobile-menu.open {
      transform: translateY(0);
    }

    .mobile-menu a {
      font-size: 22px;
      font-weight: 500;
      color: var(--primary-dark);
      border-bottom: 2px solid transparent;
    }

    .mobile-menu a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .mobile-close {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      font-size: 36px;
      color: var(--primary-dark);
      cursor: pointer;
    }

    /* Hero 背景渐变 */
    .hero-bg {
      background: linear-gradient(135deg, #F0F7FA 0%, #E8F4F8 100%);
    }

    /* 按钮样式 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      border: none;
      transition: background-color 0.2s, transform 0.2s;
      display: inline-block;
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: scale(1.03);
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      transition: background-color 0.2s, color 0.2s, transform 0.2s;
      display: inline-block;
    }

    .btn-secondary:hover {
      background-color: var(--primary);
      color: white;
      transform: scale(1.03);
    }

    .btn-white-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      transition: background-color 0.2s, color 0.2s;
    }

    .btn-white-outline:hover {
      background-color: white;
      color: var(--primary);
    }

    /* 卡片通用 */
    .card {
      background: #FFFFFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.25s ease, transform 0.25s ease;
    }

    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }

    /* 痛点解决方案卡片内部布局 */
    .pain-solution-card {
      display: flex;
      align-items: flex-start;
      gap: 24px;
      padding: 32px;
    }

    .pain-side {
      width: 30%;
      font-size: 14px;
      color: var(--text-muted);
      display: flex;
      align-items: flex-start;
      gap: 8px;
    }

    .solution-side {
      width: 70%;
      font-size: 16px;
      color: var(--primary-dark);
      font-weight: 500;
      display: flex;
      align-items: flex-start;
      gap: 8px;
    }

    .icon-dot {
      width: 20px;
      height: 20px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 16px;
    }

    /* 成果数字 */
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-gold);
      line-height: 1.2;
    }

    /* 证言卡片 */
    .testimonial-card {
      display: flex;
      gap: 32px;
      align-items: flex-start;
      background: #FFFFFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 32px;
    }

    .quote-line {
      width: 4px;
      background-color: var(--primary);
      border-radius: 2px;
      align-self: stretch;
      margin-right: 16px;
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      font-size: 18px;
      font-weight: 600;
      color: var(--primary-dark);
      padding: 20px 0;
      display: flex;
      align-items: center;
      gap: 12px;
      cursor: pointer;
      transition: color 0.2s;
    }

    .faq-question:hover {
      color: var(--primary);
    }

    .faq-dot {
      width: 8px;
      height: 8px;
      background-color: var(--primary);
      border-radius: 50%;
      transition: all 0.2s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, background-color 0.25s;
      background-color: transparent;
      border-radius: 6px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      background-color: var(--primary-light);
      padding: 0 20px 20px 20px;
    }

    .faq-item.active .faq-dot {
      background-color: var(--accent-gold);
      transform: rotate(180deg);
      border-radius: 2px;
      width: 0;
      height: 0;
      border-left: 6px solid transparent;
      border-right: 6px solid transparent;
      border-top: 8px solid var(--accent-gold);
      background: transparent;
    }

    /* 页脚 */
    .footer-bg {
      background-color: #1A202C;
    }

    /* 响应式 */
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .container-custom {
        padding-left: 20px;
        padding-right: 20px;
      }
      .pain-solution-card {
        flex-direction: column;
        gap: 16px;
      }
      .pain-side, .solution-side {
        width: 100%;
      }
      .testimonial-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
      }
      .quote-line {
        display: none;
      }
      .hero-grid {
        flex-direction: column;
      }
      .stat-number {
        font-size: 40px;
      }
      h1 {
        font-size: 32px !important;
      }
      h2 {
        font-size: 28px !important;
      }
      .section-spacing {
        padding-top: 64px;
        padding-bottom: 64px;
      }
    }

    @media (max-width: 520px) {
      .btn-primary, .btn-secondary {
        padding: 12px 24px;
        font-size: 15px;
      }
      .card {
        padding: 24px;
      }
    }

    .section-spacing {
      padding-top: 120px;
      padding-bottom: 120px;
    }