/* roulang page: index */
:root {
      --bg-deep: #0B0C10;
      --bg-purple: #1A0F2E;
      --primary: #8B5CF6;
      --primary-light: #A855F7;
      --accent: #06B6D4;
      --accent-glow: #22D3EE;
      --text-white: #FFFFFF;
      --text-gray: #CBD5E1;
      --text-muted: #94A3B8;
      --card-bg: rgba(255, 255, 255, 0.03);
      --card-border: rgba(255, 255, 255, 0.06);
      --shadow-glow: 0 0 25px rgba(139, 92, 246, 0.25);
      --radius-lg: 16px;
      --radius-md: 12px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, sans-serif;
      --transition: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-gray);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    h1, h2, h3, h4 {
      color: var(--text-white);
      font-weight: 700;
      letter-spacing: -0.3px;
    }

    h1 { font-size: 3rem; line-height: 1.2; }
    h2 { font-size: 2.25rem; line-height: 1.3; }
    h3 { font-size: 1.5rem; line-height: 1.4; }
    .text-lead { font-size: 1.2rem; }

    @media (max-width: 768px) {
      h1 { font-size: 2rem; }
      h2 { font-size: 1.8rem; }
      h3 { font-size: 1.3rem; }
    }

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

    a {
      color: var(--accent);
      text-decoration: none;
      transition: color var(--transition);
    }
    a:hover {
      color: var(--accent-glow);
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 星空动态背景 */
    .hero-stars {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(ellipse at 20% 50%, #1A0F2E 0%, #0B0C10 90%);
      overflow: hidden;
      z-index: 0;
    }
    .stars-particle {
      position: absolute;
      background: white;
      border-radius: 50%;
      opacity: 0.7;
      animation: float 6s infinite alternate;
    }
    @keyframes float {
      0% { transform: translateY(0px); opacity: 0.3; }
      100% { transform: translateY(-25px); opacity: 0.8; }
    }

    /* 玻璃卡片 */
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(8px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 2rem;
      transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
    }
    .glass-card:hover {
      border-color: rgba(139, 92, 246, 0.3);
      transform: translateY(-6px);
      box-shadow: var(--shadow-glow);
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-md);
      font-weight: 600;
      letter-spacing: 0.5px;
      transition: background var(--transition), box-shadow var(--transition);
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--primary-light);
      box-shadow: 0 0 18px var(--primary);
      color: white;
    }

    .btn-outline {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.4);
      color: white;
      padding: 0.7rem 2rem;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: all var(--transition);
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: var(--primary);
      border-color: var(--primary);
      box-shadow: 0 0 12px var(--primary);
      color: white;
    }

    /* 导航 */
    .nav-blur {
      background: rgba(11, 12, 16, 0.8);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .nav-link {
      color: var(--text-gray);
      font-weight: 500;
      transition: color var(--transition);
      padding: 0.5rem 0.25rem;
    }
    .nav-link:hover {
      color: var(--accent-glow);
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      color: var(--text-white);
      font-weight: 600;
      font-size: 1.1rem;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      transition: color var(--transition);
    }
    .faq-question:hover {
      color: var(--accent-glow);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-gray);
      padding: 0 0 0 1rem;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1.2rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
      color: var(--accent);
    }
    .faq-icon {
      font-size: 1.5rem;
      transition: transform 0.3s;
    }

    @media (max-width: 768px) {
      .container { padding-left: 1rem; padding-right: 1rem; }
    }