/* roulang page: index */
/* 自定义设计系统与全局视觉变量 */
    :root {
      --primary-red: #E8472B;
      --deep-navy: #1B1B2F;
      --warm-sand: #F5F0E8;
      --golden-yellow: #FFB81C;
      --text-main: #1B1B2F;
      --text-secondary: #4A4A5A;
      --text-muted: #8C8C9A;
      --success-green: #0FA96B;
      --card-white: #FFFFFF;
      --shadow-sm: 0 4px 24px rgba(27, 27, 47, 0.06);
      --shadow-hover: 0 12px 32px rgba(27, 27, 47, 0.12);
      --border-radius-card: 16px;
      --border-radius-btn: 40px;
      --transition-smooth: all 0.3s ease;
    }

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

    body {
      font-family: 'PingFang SC', '思源黑体', 'Inter', 'Roboto', system-ui, -apple-system, sans-serif;
      background-color: var(--warm-sand);
      color: var(--text-main);
      line-height: 1.8;
      font-weight: 400;
      overflow-x: hidden;
    }

    /* 容器与栅格 */
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 2rem;
      padding-right: 2rem;
    }

    /* 主标题字体 */
    h1, h2, h3, .font-heavy {
      font-weight: 900;
      letter-spacing: -0.5px;
    }
    h2 {
      font-weight: 800;
      font-size: 2.5rem;
    }
    .data-number {
      font-family: 'DIN Alternate', 'Inter', system-ui, sans-serif;
      font-weight: 700;
    }

    /* 导航栏样式 - 起始透明，滚动后变白 */
    #main-nav {
      transition: background-color 0.35s ease, box-shadow 0.35s ease;
      background-color: transparent;
      box-shadow: none;
    }
    .nav-scrolled {
      background-color: white !important;
      box-shadow: 0 4px 24px rgba(0,0,0,0.05) !important;
    }
    .nav-link {
      color: white;
      transition: color 0.2s ease;
    }
    .nav-scrolled .nav-link {
      color: var(--text-main) !important;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--golden-yellow) !important;
    }
    .nav-scrolled .nav-link:hover, .nav-scrolled .nav-link.active {
      color: var(--primary-red) !important;
    }
    .cta-btn-nav {
      background-color: var(--primary-red);
      color: white;
      border-radius: 40px;
      padding: 0.6rem 1.8rem;
      font-weight: 600;
      transition: var(--transition-smooth);
      border: none;
    }
    .cta-btn-nav:hover {
      background-color: var(--golden-yellow);
      color: var(--deep-navy);
    }

    /* 移动端菜单遮盖 */
    .mobile-menu {
      background-color: var(--warm-sand);
    }

    /* Hero 区域背景与遮罩 */
    .hero-bg {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero-overlay {
      background-color: rgba(27, 27, 47, 0.6);
      position: absolute;
      inset: 0;
    }

    /* 卡片与容器 */
    .card-custom {
      background: var(--card-white);
      border-radius: var(--border-radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
      overflow: hidden;
    }
    .card-custom:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .pain-card {
      border-left: 6px solid var(--primary-red);
      padding: 1.8rem;
      background: white;
      border-radius: 0 16px 16px 0;
      box-shadow: 0 6px 18px rgba(0,0,0,0.04);
    }

    /* 解决方案卡片hover描边 */
    .solution-card:hover {
      outline: 2px solid var(--primary-red);
      outline-offset: -2px;
    }

    /* 手风琴样式 */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.06);
    }
    .faq-question {
      cursor: pointer;
      padding: 1.5rem 0;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease;
      color: var(--text-secondary);
      border-left: 4px solid var(--primary-red);
      padding-left: 1.5rem;
      margin-left: 0.5rem;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding-top: 0.8rem;
      padding-bottom: 1.5rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    .faq-icon {
      transition: transform 0.3s ease;
      color: var(--primary-red);
    }

    /* 统计数字简单动画激活样式 */
    .count-up {
      transition: opacity 0.6s ease;
    }

    /* 页脚链接样式 */
    .footer-link {
      color: rgba(255,255,255,0.75);
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: var(--golden-yellow);
    }

    /* 自定义按钮统一样式 */
    .btn-primary {
      background-color: var(--primary-red);
      color: white;
      border-radius: var(--border-radius-btn);
      padding: 0.9rem 2.6rem;
      font-weight: 600;
      display: inline-block;
      transition: var(--transition-smooth);
      text-align: center;
      border: none;
      cursor: pointer;
      box-shadow: 0 6px 14px rgba(232,71,43,0.3);
    }
    .btn-primary:hover {
      background-color: var(--golden-yellow);
      color: var(--deep-navy);
      box-shadow: 0 10px 24px rgba(255,184,28,0.4);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-red);
      color: var(--primary-red);
      border-radius: var(--border-radius-btn);
      padding: 0.9rem 2.6rem;
      font-weight: 600;
      display: inline-block;
      transition: var(--transition-smooth);
    }
    .btn-outline:hover {
      background-color: rgba(232,71,43,0.06);
      border-color: var(--primary-red);
    }

    @media (max-width: 768px) {
      .container-custom {
        padding-left: 1.25rem;
        padding-right: 1.25rem;
      }
      h2 {
        font-size: 2rem;
      }
      .mobile-ctl {
        display: block;
      }
    }