/* roulang page: index */
/* 基础重置与设计变量 */
    :root {
      --primary: #FF6B35;
      --primary-dark: #E55A2B;
      --func-green: #00B578;
      --warning: #FF9F0A;
      --text-main: #1F2329;
      --text-secondary: #86909C;
      --bg-page: #F5F6FA;
      --border-light: #E8ECF1;
      --white: #FFFFFF;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      margin: 0;
      background-color: var(--bg-page);
      color: var(--text-main);
      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;
    }
    .container-custom {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 767px) {
      .container-custom {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航下划线动效 */
    .nav-link {
      position: relative;
      padding-bottom: 4px;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 0;
      height: 2px;
      background-color: var(--primary);
      transition: width 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    /* 卡片悬浮动效 */
    .card-hover {
      transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .card-hover:hover {
      box-shadow: 0 8px 24px rgba(0,0,0,0.10);
      transform: translateY(-4px);
    }
    /* 手风琴动画 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-in-out;
    }
    .faq-item.active .faq-content {
      max-height: 200px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-icon {
      transition: transform 0.25s;
    }
    /* 输入框聚焦 */
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(255,107,53,0.15);
    }
    /* 移动端菜单 */
    .mobile-menu {
      transition: opacity 0.3s ease, visibility 0.3s;
    }
    .mobile-menu.hidden {
      opacity: 0;
      visibility: hidden;
    }