/* roulang page: index */
:root {
      --primary: #2E3A8C;
      --primary-dark: #1E2A6C;
      --accent: #00B4D8;
      --bg-light: #F5F6FA;
      --white: #FFFFFF;
      --text-dark: #1F2329;
      --text-muted: #86909C;
      --border-light: #E5E7EB;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --shadow-hero: 0 16px 48px rgba(46,58,140,0.25);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-full: 24px;
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.6;
      scroll-behavior: smooth;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 640px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
      transition: background 0.2s ease, box-shadow 0.2s ease;
    }
    .navbar.scrolled {
      background: rgba(255,255,255,0.98);
      box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    }
    .nav-link {
      color: var(--text-dark);
      font-weight: 500;
      transition: color 0.2s;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 10px 24px;
      font-weight: 600;
      transition: background 0.2s, transform 0.1s;
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 10px 24px;
      font-weight: 600;
      transition: all 0.2s;
    }
    .btn-outline:hover {
      background: #EEF0FA;
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 32px;
      font-weight: 700;
      transition: background 0.2s;
    }
    .btn-accent:hover {
      background: #0099b8;
    }
    /* 汉堡菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: white;
      z-index: 40;
      flex-direction: column;
      padding: 24px;
    }
    .mobile-menu.active {
      display: flex;
    }
    /* Hero */
    .hero-bg {
      background: linear-gradient(135deg, #0B0F2A 0%, #1A1F4E 50%, #0D1130 100%);
      min-height: 90vh;
      position: relative;
      overflow: hidden;
    }
    .star {
      position: absolute;
      background: white;
      border-radius: 50%;
      opacity: 0.4;
      animation: float 6s infinite alternate;
    }
    @keyframes float {
      0% { transform: translateY(0px); opacity: 0.3; }
      100% { transform: translateY(-20px); opacity: 0.7; }
    }
    .card-product {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      overflow: hidden;
      border: 1px solid transparent;
    }
    .card-product:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary);
    }
    .tag {
      background: #EEF0FA;
      color: var(--primary);
      border-radius: 12px;
      padding: 4px 12px;
      font-size: 12px;
      font-weight: 500;
      display: inline-block;
    }
    .pricing-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: all 0.2s;
    }
    .pricing-card.featured {
      border: 2px solid var(--primary);
      transform: scale(1.03);
      box-shadow: var(--shadow-md);
    }
    .faq-item {
      border-bottom: 1px solid #eee;
      padding: 20px 0;
    }
    .faq-question {
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--text-dark);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: #555;
      padding-top: 0;
      border-top: 1px solid transparent;
    }
    .faq-answer.open {
      max-height: 200px;
      padding-top: 16px;
      border-top-color: #eee;
    }
    footer {
      background: #1F2329;
      color: #aaa;
    }
    footer a:hover {
      color: white;
    }
    @media (max-width: 768px) {
      .hero-bg {
        min-height: 80vh;
      }
      h1 {
        font-size: 2rem !important;
      }
      .pricing-card.featured {
        transform: none;
      }
    }