/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #0A6E79;
      --primary-dark: #08555E;
      --accent: #F85C2B;
      --accent-dark: #E04A1A;
      --bg-light: #F4F6F8;
      --bg-white: #FFFFFF;
      --bg-dark: #1A1D22;
      --bg-darker: #111317;
      --text-main: #1A1D22;
      --text-body: #4A4F57;
      --text-muted: #8B919A;
      --border-light: #E2E6EB;
      --shadow-card: 0 4px 24px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 12px 32px rgba(0,0,0,0.1);
      --shadow-btn: 0 8px 20px rgba(248,92,43,0.3);
      --radius-md: 8px;
      --radius-lg: 12px;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', 'Helvetica Neue', sans-serif;
      background-color: var(--bg-white);
      color: var(--text-body);
      line-height: 1.7;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }
    
    h1, h2, h3, h4, .font-display {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: -0.3px;
    }
    
    .section-title {
      font-size: 2.25rem;
      line-height: 1.3;
      margin-bottom: 1rem;
      position: relative;
    }
    
    .section-subtitle {
      font-size: 1.125rem;
      color: var(--text-muted);
      max-width: 700px;
      margin-left: auto;
      margin-right: auto;
      margin-bottom: 3rem;
    }
    
    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    
    /* 导航样式 */
    .navbar {
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(12px);
      height: 72px;
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 50;
      display: flex;
      align-items: center;
    }
    
    .nav-link {
      color: var(--text-body);
      font-weight: 500;
      transition: color 0.2s;
      position: relative;
      padding: 0.5rem 1rem;
    }
    
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    
    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 0.75rem 2rem;
      transition: all 0.3s ease;
      display: inline-block;
      text-align: center;
      box-shadow: 0 4px 12px rgba(248,92,43,0.2);
    }
    
    .btn-primary:hover {
      background: var(--accent-dark);
      box-shadow: var(--shadow-btn);
      transform: translateY(-1px);
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 0.7rem 1.8rem;
      transition: all 0.3s ease;
    }
    
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    
    /* 卡片组件 */
    .card {
      background: white;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      overflow: hidden;
    }
    
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    
    /* 手风琴 */
    .faq-item {
      border-top: 1px solid var(--border-light);
      padding: 1.25rem 0;
      cursor: pointer;
    }
    
    .faq-question {
      font-weight: 600;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease;
      color: var(--text-body);
      padding-right: 2rem;
    }
    
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-top: 1rem;
      padding-bottom: 0.5rem;
    }
    
    .faq-icon {
      color: var(--accent);
      font-size: 1.2rem;
      transition: transform 0.3s;
    }
    
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    
    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: white;
      z-index: 40;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      transform: translateX(100%);
      transition: transform 0.4s ease;
    }
    
    .mobile-menu.open {
      transform: translateX(0);
    }
    
    @media (min-width: 769px) {
      .mobile-menu, .hamburger {
        display: none;
      }
    }
    
    /* 响应式微调 */
    @media (max-width: 768px) {
      .container-custom {
        padding: 0 1.5rem;
      }
      .section-title {
        font-size: 1.8rem;
      }
    }