/* roulang page: index */
/* 设计变量与全局样式 */
    :root {
      --brand-deep: #1E1E1E;
      --brand-accent: #F15A24;
      --brand-accent-hover: #D84A1A;
      --brand-slate: #2C3E50;
      --bg-warm: #F5F3F0;
      --card-white: #FFFFFF;
      --success-green: #10B981;
      --muted-gray: #D1D5DB;
      --text-primary: #1E1E1E;
      --text-secondary: #4B5563;
      --text-light: #6B7280;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      font-weight: 400;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航卡片面板 */
    .nav-panel {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      border-radius: 16px;
      box-shadow: var(--shadow-sm);
      margin-top: 12px;
      padding: 8px 20px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }

    .nav-icon-card {
      width: 48px;
      height: 48px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      border-radius: 12px;
      transition: all 0.2s ease;
      color: var(--text-secondary);
      font-size: 0.7rem;
      font-weight: 500;
      gap: 2px;
    }

    .nav-icon-card.active {
      background-color: rgba(241,90,36,0.08);
      color: var(--brand-accent);
    }

    .nav-icon-card:hover {
      background-color: rgba(0,0,0,0.03);
      color: var(--brand-accent);
    }

    .btn-primary {
      background: var(--brand-accent);
      color: white;
      border: none;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 10px rgba(241,90,36,0.2);
      white-space: nowrap;
    }

    .btn-primary:hover {
      background: var(--brand-accent-hover);
      transform: scale(1.02);
      box-shadow: 0 6px 16px rgba(241,90,36,0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--brand-accent);
      color: var(--brand-accent);
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    .btn-outline:hover {
      background: rgba(241,90,36,0.08);
    }

    /* 数据卡片 */
    .metric-card {
      background: rgba(255,255,255,0.75);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    .metric-number {
      font-size: 2.5rem;
      font-weight: 800;
      color: var(--brand-accent);
      font-variant-numeric: tabular-nums;
      line-height: 1.2;
    }

    .service-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      border-left: 4px solid var(--brand-accent);
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-left-width: 8px;
    }

    .compare-card-left {
      background: #F9FAFB;
      border-radius: var(--radius-card);
      padding: 28px;
      color: var(--text-secondary);
    }

    .compare-card-right {
      background: #FFF7F4;
      border-radius: var(--radius-card);
      padding: 28px;
      border: 1px solid rgba(241,90,36,0.25);
    }

    .faq-item {
      background: var(--card-white);
      border-radius: 8px;
      padding: 18px 22px;
      margin-bottom: 12px;
      cursor: pointer;
      transition: all 0.3s ease;
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      border-left: 3px solid transparent;
    }

    .faq-item.open {
      border-left-color: var(--brand-accent);
      background: #FFFBF9;
    }

    .footer-link:hover {
      color: var(--brand-accent);
    }

    @media (max-width: 768px) {
      .nav-panel {
        flex-direction: column;
        align-items: stretch;
        padding: 16px;
      }
      .nav-links-group {
        justify-content: center;
        flex-wrap: wrap;
      }
      .service-card {
        border-left: none;
        border-top: 4px solid var(--brand-accent);
      }
      .service-card:hover {
        border-top-width: 8px;
      }
    }

    /* 汉堡菜单移动端 */
    .mobile-menu {
      display: none;
    }
    @media (max-width: 640px) {
      .desktop-nav-cards {
        display: none;
      }
      .mobile-menu {
        display: block;
      }
      .nav-panel {
        flex-direction: row;
        flex-wrap: wrap;
        align-items: center;
      }
    }

    @media (min-width: 641px) {
      .mobile-menu {
        display: none;
      }
      .desktop-nav-cards {
        display: flex;
      }
    }