/* roulang page: index */
:root {
      --primary: #1A3C5E;
      --accent: #C8963E;
      --accent-hover: #B8862D;
      --bg: #F7F9FC;
      --text: #1E293B;
      --text-soft: #64748B;
      --highlight-bg: #E8F0FE;
      --border: #E2E8F0;
      --card-bg: #FFFFFF;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-body);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      margin: 0;
      font-weight: 600;
    }
    h1 {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.2;
    }
    h2 {
      font-size: 32px;
      line-height: 1.3;
    }
    h3 {
      font-size: 20px;
      line-height: 1.4;
    }
    .text-soft {
      color: var(--text-soft);
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .section-padding {
      padding: 100px 0;
    }
    .btn-primary {
      background-color: var(--accent);
      color: white;
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.3s ease;
      display: inline-block;
      text-decoration: none;
      border: none;
      cursor: pointer;
      box-shadow: 0 2px 8px rgba(0,0,0,0.08);
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background-color: var(--accent-hover);
      box-shadow: var(--shadow-md);
      transform: translateY(-2px);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-sm);
      padding: 10px 26px;
      font-weight: 600;
      transition: all 0.3s ease;
      display: inline-block;
      text-decoration: none;
      cursor: pointer;
    }
    .btn-secondary:hover {
      background-color: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .text-link {
      color: var(--primary);
      text-decoration: none;
      font-weight: 500;
      transition: color 0.2s;
      position: relative;
      padding-bottom: 2px;
    }
    .text-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 1.5px;
      background-color: var(--accent);
      transition: width 0.25s ease;
    }
    .text-link:hover {
      color: var(--accent);
    }
    .text-link:hover::after {
      width: 100%;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      padding: 24px;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .nav-link {
      color: #475569;
      font-size: 15px;
      font-weight: 500;
      text-decoration: none;
      padding: 8px 0;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link.active {
      color: var(--primary);
      font-weight: 600;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--primary);
    }
    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 16px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 18px;
      color: var(--text);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s ease;
      background-color: #F8FAFC;
      border-radius: 8px;
      margin-top: 8px;
      padding: 0 16px;
      color: var(--text-soft);
      font-size: 15px;
      line-height: 1.6;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    /* 移动菜单 */
    .mobile-menu {
      display: none;
    }
    @media (max-width: 1024px) {
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .section-padding { padding: 70px 0; }
    }
    @media (max-width: 768px) {
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .section-padding { padding: 60px 0; }
      .container { padding: 0 20px; }
      .desktop-nav { display: none; }
      .mobile-menu { display: block; }
      .hero-flex { flex-direction: column-reverse; }
      .hero-img { margin-bottom: 24px; }
    }