/* roulang page: index */
:root {
      --primary: #0A2540;
      --secondary: #00A3E0;
      --accent: #FF6B35;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text: #1E293B;
      --text-secondary: #475569;
      --text-muted: #94A3B8;
      --border: #E2E8F0;
      --radius: 12px;
      --shadow: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --transition: 0.3s ease;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-inter: 'Inter', var(--font-sans);
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      color: var(--text);
      background: var(--bg);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .font-inter {
      font-family: var(--font-inter);
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      letter-spacing: -0.02em;
      color: var(--primary);
    }
    h1 {
      font-size: 48px;
      line-height: 1.16;
      font-weight: 700;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 36px;
      line-height: 1.22;
      font-weight: 600;
    }
    h3 {
      font-size: 24px;
      line-height: 1.33;
      font-weight: 600;
    }
    h4 {
      font-size: 20px;
      line-height: 1.4;
      font-weight: 500;
    }
    p {
      color: var(--text-secondary);
      font-size: 16px;
      line-height: 26px;
    }
    .small-text {
      font-size: 14px;
      line-height: 20px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border-radius: 8px;
      font-weight: 600;
      transition: var(--transition);
      cursor: pointer;
      text-decoration: none;
      border: 1.5px solid transparent;
      font-size: 16px;
      min-width: 120px;
      min-height: 44px;
      padding: 12px 28px;
    }
    .btn-primary {
      background: var(--secondary);
      color: white;
      border-color: var(--secondary);
    }
    .btn-primary:hover {
      background: #008CC1;
      border-color: #008CC1;
      box-shadow: 0 4px 14px rgba(0,163,224,0.3);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background: rgba(10,37,64,0.05);
      border-color: var(--primary);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      border-color: var(--accent);
      padding: 16px 40px;
      font-size: 17px;
      border-radius: 8px;
    }
    .btn-accent:hover {
      transform: scale(1.03);
      background: #e85d2c;
      box-shadow: 0 6px 20px rgba(255,107,53,0.35);
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .tag {
      display: inline-block;
      background: rgba(0,163,224,0.1);
      color: var(--secondary);
      font-size: 13px;
      font-weight: 500;
      padding: 4px 12px;
      border-radius: 20px;
      letter-spacing: 0.3px;
    }
    .section {
      padding: 80px 0;
    }
    .section-title {
      margin-bottom: 16px;
    }
    .section-desc {
      color: var(--text-secondary);
      max-width: 640px;
      margin: 0 auto 48px;
      text-align: center;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      border-bottom: 1px solid var(--border);
      z-index: 50;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      text-decoration: none;
      letter-spacing: -0.3px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--primary);
      font-weight: 500;
      font-size: 15px;
      transition: color 0.2s;
      position: relative;
      padding: 8px 0;
    }
    .nav-links a:hover {
      color: var(--secondary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--secondary);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--primary);
      cursor: pointer;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      border-bottom: 1px solid var(--border);
      flex-direction: column;
      padding: 20px 24px;
      gap: 18px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.05);
      z-index: 49;
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--primary);
      text-decoration: none;
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
    }
    /* 对比表 */
    .compare-table {
      background: white;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow);
    }
    .table-row {
      display: flex;
      border-bottom: 1px solid #f1f5f9;
    }
    .table-row:last-child { border-bottom: none; }
    .table-cell {
      flex: 1;
      padding: 20px 24px;
      font-size: 15px;
    }
    .table-header {
      background: var(--primary);
      color: white;
      font-weight: 600;
    }
    .table-highlight {
      color: var(--secondary);
      font-weight: 700;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--primary);
      transition: color 0.2s;
    }
    .faq-question:hover { color: var(--secondary); }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--secondary);
    }
    @media (max-width: 768px) {
      h1 { font-size: 36px; line-height: 1.2; }
      h2 { font-size: 28px; }
      .section { padding: 60px 0; }
      .container { padding: 0 20px; }
    }