/* roulang page: index */
/* 设计变量与全局样式 */
    :root {
      --primary: #2E4A3A;
      --primary-light: #3A5C4A;
      --accent: #C49A6C;
      --accent-light: #D4B28C;
      --bg-warm: #F7F5F0;
      --text-dark: #1E1E1E;
      --text-secondary: #3A3A3A;
      --text-muted: #5A5A5A;
      --white: #FFFFFF;
      --border-soft: #E5E0D8;
      --card-shadow: 0 4px 20px rgba(0,0,0,0.04);
      --card-shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 20px;
      --radius-badge: 12px;
      --radius-btn: 10px;
      --nav-width: 260px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', sans-serif;
      --font-number: 'Inter', 'Segoe UI', system-ui, sans-serif;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-dark);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    
    /* 数字与英文使用 Inter 字体 */
    .font-number {
      font-family: var(--font-number);
    }
    
    /* 自定义渐变文字 */
    .text-gradient {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    
    /* 主按钮样式 */
    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      color: white;
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      display: inline-block;
      transition: all 0.25s ease;
      box-shadow: 0 4px 12px rgba(46,74,58,0.2);
      border: none;
      cursor: pointer;
      text-align: center;
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 8px 20px rgba(46,74,58,0.3);
      transform: scale(1.03);
    }
    
    /* 次要按钮 */
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      display: inline-block;
      transition: all 0.25s ease;
      cursor: pointer;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(196,154,108,0.1);
      border-color: var(--accent-light);
      color: var(--accent-light);
    }
    
    /* 卡片基础 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      transition: all 0.3s ease;
    }
    .card:hover {
      box-shadow: var(--card-shadow-hover);
      transform: translateY(-6px);
    }
    
    /* 服务卡片底部渐变条 */
    .service-card {
      position: relative;
      overflow: hidden;
    }
    .service-card::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 4px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      transform: scaleX(0);
      transform-origin: left;
      transition: transform 0.3s ease;
    }
    .service-card:hover::after {
      transform: scaleX(1);
    }
    
    /* 固定左侧导航 */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background-color: var(--primary);
      color: white;
      z-index: 50;
      display: flex;
      flex-direction: column;
      padding: 2rem 1.5rem;
      box-shadow: 2px 0 15px rgba(0,0,0,0.08);
    }
    
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      max-width: 1400px;
    }
    
    /* 导航链接 */
    .nav-link {
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      font-size: 1rem;
      padding: 0.6rem 0.8rem;
      border-left: 3px solid transparent;
      transition: all 0.2s;
      display: block;
      text-decoration: none;
    }
    .nav-link:hover {
      color: white;
      border-left-color: var(--accent);
      background: rgba(255,255,255,0.05);
    }
    .nav-link.active {
      color: white;
      font-weight: 600;
      border-left-color: var(--accent);
      background: rgba(255,255,255,0.08);
    }
    
    /* 移动端汉堡菜单 */
    .mobile-nav {
      display: none;
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-soft);
    }
    .faq-question {
      cursor: pointer;
      padding: 18px 0;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-dark);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s ease;
      color: #4A4A4A;
      font-size: 0.95rem;
      line-height: 1.7;
      padding-left: 28px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 18px;
    }
    .faq-item.active .faq-question {
      color: var(--primary);
    }
    
    /* 响应式设计 */
    @media (max-width: 1024px) {
      :root {
        --nav-width: 0px;
      }
      .app-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 70px;
        background: var(--primary);
        z-index: 60;
        align-items: center;
        justify-content: space-between;
        padding: 0 1.5rem;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 70px;
      }
      /* 抽屉菜单 */
      .drawer {
        position: fixed;
        top: 0;
        left: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--primary);
        z-index: 70;
        transition: left 0.3s ease;
        padding: 2rem;
        display: flex;
        flex-direction: column;
      }
      .drawer.open {
        left: 0;
      }
      .drawer a {
        color: white;
        font-size: 1.2rem;
        padding: 1rem 0;
        border-bottom: 1px solid rgba(255,255,255,0.2);
        text-decoration: none;
      }
      .overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0,0,0,0.5);
        z-index: 65;
        display: none;
      }
      .overlay.show {
        display: block;
      }
      .card-grid {
        grid-template-columns: repeat(2,1fr);
      }
      .data-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }
    
    @media (max-width: 768px) {
      .card-grid {
        grid-template-columns: 1fr;
      }
      .data-grid {
        grid-template-columns: repeat(2,1fr);
      }
      .hero-text h1 {
        font-size: 2.2rem;
      }
      .section-padding {
        padding: 3rem 1.5rem;
      }
      .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
      }
    }