/* roulang page: index */
:root {
      --primary-cyan: #00F0FF;
      --deep-purple: #2D0B4E;
      --accent-orange: #FF6B35;
      --bg-deep: #0A0A0F;
      --bg-card: #16162A;
      --text-white: #FFFFFF;
      --text-light: #B0B0C0;
      --text-muted: #8888A0;
      --border-glow: rgba(0, 240, 255, 0.2);
      --shadow-glow: 0 0 20px rgba(0, 240, 255, 0.15);
      --rounded-card: 1.5rem;
      --rounded-btn: 0.9rem;
      --font-sans: "Inter", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
      scroll-behavior: smooth;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-light);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    /* 自定义导航栏 */
    .navbar {
      background: rgba(10, 10, 15, 0.85);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.08);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .navbar.scrolled {
      background: rgba(10, 10, 15, 0.95);
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
    }
    .nav-link {
      transition: color 0.2s, text-shadow 0.2s;
      position: relative;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-cyan);
      transition: width 0.25s ease;
      box-shadow: 0 0 8px var(--primary-cyan);
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    .btn-primary {
      background: linear-gradient(135deg, #00F0FF 0%, #FF6B35 100%);
      border: none;
      color: white;
      font-weight: 600;
      border-radius: var(--rounded-btn);
      padding: 0.7rem 1.8rem;
      transition: all 0.3s ease;
      box-shadow: 0 0 14px rgba(0, 240, 255, 0.4);
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      transform: translateY(-2px) scale(1.02);
      box-shadow: 0 0 28px rgba(0, 240, 255, 0.7);
      filter: brightness(1.1);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-cyan);
      color: var(--primary-cyan);
      font-weight: 600;
      border-radius: var(--rounded-btn);
      padding: 0.65rem 1.8rem;
      transition: all 0.3s ease;
    }
    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.08);
      border-color: #fff;
      color: #fff;
      transform: translateY(-2px);
    }
    .card-glow {
      background: var(--bg-card);
      border: 1px solid var(--border-glow);
      border-radius: var(--rounded-card);
      box-shadow: 0 10px 25px -8px rgba(0,0,0,0.5);
      transition: all 0.3s ease;
    }
    .card-glow:hover {
      transform: translateY(-6px);
      border-color: rgba(0, 240, 255, 0.5);
      box-shadow: 0 0 30px rgba(0, 240, 255, 0.25);
    }
    .data-badge {
      background: rgba(22, 22, 42, 0.9);
      border-left: 4px solid var(--primary-cyan);
      border-radius: 1rem;
      padding: 0.8rem 1.2rem;
      backdrop-filter: blur(8px);
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: -0.5px;
      margin-bottom: 1rem;
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 1.9rem;
      }
    }
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      transition: all 0.25s;
    }
    .faq-question {
      cursor: pointer;
      font-weight: 600;
      color: #fff;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-light);
    }
    .faq-item.active .faq-answer {
      max-height: 160px;
      padding-bottom: 1.2rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
      color: var(--primary-cyan);
    }
    .hero-gradient {
      background: radial-gradient(circle at 30% 30%, #1a0033 0%, #0a0a0f 85%);
    }
    /* 移动端汉堡菜单简单处理 */
    @media (max-width: 1024px) {
      .desktop-nav {
        display: none;
      }
    }