/* roulang page: index */
/* ----- 设计变量 & 基础重置 ----- */
    :root {
      --primary: #1A5F7A;
      --primary-light: rgba(26, 95, 122, 0.05);
      --accent: #F39C12;
      --accent-hover: #E67E22;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text: #1E293B;
      --text-secondary: #64748B;
      --border: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-lg: 16px;
      --font-heading: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: all 0.2s ease;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-heading);
      background-color: var(--bg);
      color: var(--text);
      margin: 0;
      padding: 0;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    
    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      font-weight: 700;
      margin-top: 0;
    }
    
    a {
      color: var(--primary);
      text-decoration: none;
      transition: var(--transition);
    }
    
    a:hover {
      color: var(--accent);
      text-decoration: none;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, .button {
      cursor: pointer;
      font-family: var(--font-heading);
    }
    
    /* 容器微调 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    
    /* ----- 导航栏 (桌面端 & 移动端底部Tab) ----- */
    .top-nav {
      background: #fff;
      height: 64px;
      border-bottom: 1px solid var(--border);
      position: sticky;
      top: 0;
      z-index: 40;
      display: flex;
      align-items: center;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo-brand {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--primary);
      text-decoration: none;
    }
    
    .logo-brand i {
      font-size: 1.8rem;
      color: var(--accent);
    }
    
    .desktop-links {
      display: flex;
      gap: 2rem;
    }
    
    .desktop-links a {
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.5rem 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    
    .desktop-links a:hover,
    .desktop-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    
    /* 移动端汉堡菜单(仅显示，实际仍使用锚点) */
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.6rem;
      color: var(--primary);
    }
    
    /* 底部Tab导航 (移动端可见) */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: #fff;
      border-top: 1px solid var(--border);
      z-index: 45;
      justify-content: space-around;
      align-items: center;
      box-shadow: 0 -2px 10px rgba(0,0,0,0.03);
    }
    
    .mobile-bottom-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: var(--text-secondary);
      font-size: 10px;
      font-weight: 500;
      gap: 4px;
      text-decoration: none;
      min-width: 48px;
      padding: 4px 0;
    }
    
    .mobile-bottom-nav a i {
      font-size: 1.3rem;
    }
    
    .mobile-bottom-nav a.active {
      color: var(--primary);
    }
    
    /* ----- 板块通用间距 ----- */
    section {
      padding: 4rem 0;
    }
    
    .section-title {
      text-align: center;
      margin-bottom: 2.5rem;
    }
    
    .section-title h2 {
      font-size: 2rem;
      color: var(--primary);
      margin-bottom: 0.75rem;
    }
    
    .section-title p {
      color: var(--text-secondary);
      max-width: 600px;
      margin: 0 auto;
    }
    
    /* ----- 按钮体系 ----- */
    .btn-primary {
      background: var(--accent);
      color: #fff;
      border: none;
      padding: 0.75rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
      box-shadow: 0 4px 10px rgba(243, 156, 18, 0.25);
    }
    
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(243, 156, 18, 0.35);
      color: #fff;
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
    }
    
    .btn-outline:hover {
      background: var(--primary);
      color: #fff;
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }
    
    /* ----- Hero ----- */
    #hero {
      padding: 3rem 0 4rem;
      background: linear-gradient(180deg, #fff 0%, var(--bg) 100%);
    }
    
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 2.5rem;
    }
    
    .hero-text {
      flex: 1;
    }
    
    .hero-text h1 {
      font-size: 2.5rem;
      color: var(--primary);
      line-height: 1.3;
      margin-bottom: 1.25rem;
    }
    
    .hero-text .subtitle {
      color: var(--text-secondary);
      font-size: 1.15rem;
      margin-bottom: 2rem;
      max-width: 550px;
    }
    
    .hero-image {
      flex: 1;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    
    .cta-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    
    /* ----- 服务卡片 ----- */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.8rem;
    }
    
    .service-card {
      background: var(--card-bg);
      padding: 2rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border);
    }
    
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    
    .service-icon {
      font-size: 2.3rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
      display: inline-block;
      transition: transform 0.2s;
    }
    
    .service-card:hover .service-icon {
      transform: scale(1.05);
      color: var(--accent);
    }
    
    .service-card h3 {
      font-size: 1.4rem;
      margin-bottom: 0.8rem;
    }
    
    .service-metric {
      color: var(--accent);
      font-weight: 700;
      margin-top: 1rem;
      font-size: 0.9rem;
    }
    
    /* ----- 数据看板 ----- */
    .kpi-row {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      margin-bottom: 3rem;
    }
    
    .kpi-item {
      background: var(--primary-light);
      padding: 1.8rem 1rem;
      border-radius: var(--radius-card);
      text-align: center;
    }
    
    .kpi-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }
    
    .kpi-label {
      color: var(--text-secondary);
      font-size: 0.9rem;
      margin-top: 0.4rem;
    }
    
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }
    
    .compare-card {
      background: #fff;
      border-radius: var(--radius-card);
      padding: 1.8rem;
      box-shadow: var(--shadow-sm);
    }
    
    .compare-card.traditional {
      border-left: 4px solid #e74c3c;
    }
    
    .compare-card.tiqiu {
      border-left: 4px solid var(--primary);
    }
    
    .compare-card h4 {
      margin-bottom: 1rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    
    .compare-list {
      list-style: none;
      margin: 0;
      padding: 0;
    }
    
    .compare-list li {
      margin-bottom: 0.7rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      color: var(--text);
    }
    
    .compare-list i.fa-check {
      color: var(--accent);
    }
    
    /* ----- FAQ 手风琴 ----- */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 1.2rem 0;
      font-weight: 600;
      font-size: 1.05rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text);
      cursor: pointer;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: var(--bg);
      border-radius: 6px;
      padding: 0 1rem;
      color: var(--text-secondary);
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem;
      margin-bottom: 1rem;
    }
    
    .faq-item.active .faq-question {
      color: var(--primary);
    }
    
    /* ----- CTA 区 ----- */
    .cta-section {
      background: var(--primary-light);
      text-align: center;
      padding: 3.5rem 1rem;
    }
    
    /* ----- 页脚 ----- */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 3rem 0 1.5rem;
      font-size: 0.9rem;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    
    .footer a {
      color: #CBD5E1;
      text-decoration: none;
    }
    
    .footer a:hover {
      color: var(--accent);
    }
    
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 2rem;
      padding-top: 1.5rem;
      text-align: center;
      color: #94a3b8;
    }
    
    /* ----- 响应式设计 ----- */
    @media (max-width: 1024px) {
      .service-grid { grid-template-columns: repeat(2, 1fr); }
      .kpi-row { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    
    @media (max-width: 768px) {
      .desktop-links { display: none; }
      .hamburger { display: block; }
      .mobile-bottom-nav { display: flex; }
      
      .hero-grid {
        flex-direction: column;
      }
      
      .service-grid,
      .kpi-row,
      .compare-grid {
        grid-template-columns: 1fr;
      }
      
      .footer-grid {
        grid-template-columns: 1fr;
      }
      
      section {
        padding: 2.5rem 0;
      }
      
      body {
        padding-bottom: 70px; /* 为底部导航留空间 */
      }
    }