/* roulang page: index */
:root {
      --primary: #0A6EFF;
      --primary-hover: #0055CC;
      --accent: #FF6B35;
      --accent-hover: #E55A2B;
      --dark: #1E2A3A;
      --gray-bg: #F8FAFC;
      --white: #FFFFFF;
      --success: #10B981;
      --border-light: #E2E8F0;
      --text-muted: #64748B;
      --radius-lg: 0.75rem;
      --radius-chip: 1.25rem;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --transition: all 0.2s ease;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--gray-bg);
      color: var(--dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航 Chip 样式 */
    .nav-chip {
      display: inline-flex;
      align-items: center;
      padding: 0.5rem 1rem;
      border-radius: var(--radius-chip);
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--dark);
      background: transparent;
      transition: var(--transition);
      white-space: nowrap;
    }
    .nav-chip:hover {
      background: rgba(10,110,255,0.08);
      color: var(--primary);
    }
    .nav-chip.active {
      background: var(--primary);
      color: white;
      box-shadow: 0 2px 8px rgba(10,110,255,0.3);
    }
    /* 卡片通用 */
    .card {
      background: var(--white);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    /* 按钮体系 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: 8px;
      padding: 0.75rem 1.8rem;
      font-weight: 600;
      font-size: 1.05rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
      border-radius: 8px;
      padding: 0.75rem 1.8rem;
      font-weight: 600;
      font-size: 1.05rem;
      transition: var(--transition);
      cursor: pointer;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      border-radius: 8px;
      padding: 0.75rem 2rem;
      font-weight: 600;
      font-size: 1.1rem;
      box-shadow: 0 4px 10px rgba(255,107,53,0.25);
      transition: var(--transition);
      border: none;
      cursor: pointer;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      color: var(--dark);
      transition: color 0.2s;
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.2s;
      color: #475569;
      line-height: 1.7;
      font-size: 0.98rem;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-top: 1rem;
    }
    .faq-icon {
      transition: transform 0.3s;
      color: var(--primary);
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* 装饰标题 */
    .section-title {
      font-size: 2rem;
      font-weight: 600;
      color: var(--dark);
      margin-bottom: 1rem;
      display: flex;
      align-items: center;
      gap: 1rem;
    }
    .section-title::before {
      content: '';
      display: inline-block;
      width: 6px;
      height: 28px;
      background: var(--primary);
      border-radius: 4px;
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 1.6rem;
      }
    }
    /* 数据指标 */
    .stat-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    /* 移动端汉堡菜单 */
    .mobile-menu {
      display: none;
      flex-direction: column;
      position: fixed;
      top: 70px;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(12px);
      padding: 1.2rem;
      box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      z-index: 50;
      border-radius: 0 0 1rem 1rem;
    }
    .mobile-menu.open {
      display: flex;
    }
    @media (min-width: 769px) {
      .mobile-menu {
        display: none !important;
      }
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      cursor: pointer;
      color: var(--dark);
    }
    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .desktop-nav {
        display: none;
      }
    }
    footer {
      background: #1E2A3A;
      color: #CBD5E1;
      padding: 3rem 0 1.5rem;
    }
    footer a:hover {
      color: var(--accent);
    }