/* roulang page: index */
:root {
      --primary-bg: #0A0E27;
      --neon-green: #00F0A8;
      --electric-purple: #7B2FFF;
      --surface-glass: rgba(255,255,255,0.04);
      --surface-hover: rgba(255,255,255,0.08);
      --text-main: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #8899AA;
      --border-light: rgba(255,255,255,0.08);
      --border-active: rgba(0,240,168,0.4);
      --card-radius: 16px;
      --btn-radius: 50px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.3);
      --glow-green: 0 0 20px rgba(0,240,168,0.3);
      --glow-purple: 0 0 15px rgba(123,47,255,0.3);
      --transition-smooth: all 0.35s cubic-bezier(0.23,1,0.32,1);
      --font-heading: 'Inter', '思源黑体', 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', sans-serif;
      --font-body: 'Inter', '思源黑体', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--primary-bg);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    h1, h2, h3, h4, .h1, .h2, .h3 {
      font-family: var(--font-heading);
      color: var(--text-main);
      margin-bottom: 0.75rem;
      font-weight: 700;
      letter-spacing: -0.2px;
    }

    h1 {
      font-size: 42px;
      line-height: 1.25;
      font-weight: 700;
    }

    h2 {
      font-size: 32px;
      line-height: 1.3;
      margin-bottom: 1rem;
    }

    h3 {
      font-size: 20px;
      line-height: 1.4;
      font-weight: 600;
    }

    .text-muted {
      color: var(--text-muted);
    }

    .text-neon {
      color: var(--neon-green);
    }

    a {
      color: var(--neon-green);
      text-decoration: none;
      transition: var(--transition-smooth);
    }

    a:hover {
      color: #33FFB9;
      text-decoration: none;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 顶部信息条 */
    .top-bar {
      background: rgba(255,255,255,0.03);
      height: 36px;
      line-height: 36px;
      font-size: 13px;
      color: var(--text-muted);
      border-bottom: 1px solid rgba(255,255,255,0.05);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
    }

    .top-bar a {
      color: var(--neon-green);
      margin-left: 1.5rem;
      font-weight: 500;
    }

    /* 主导航 */
    .main-nav {
      background: rgba(10,14,39,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      height: 72px;
      display: flex;
      align-items: center;
      position: sticky;
      top: 0;
      z-index: 50;
      border-bottom: 1px solid rgba(255,255,255,0.05);
      padding: 0 1.5rem;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
    }

    .logo {
      font-family: var(--font-heading);
      font-size: 24px;
      font-weight: 700;
      color: var(--neon-green);
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .logo .divider {
      width: 1px;
      height: 24px;
      background: var(--electric-purple);
      margin-left: 0.5rem;
      opacity: 0.7;
    }

    .nav-links {
      display: flex;
      gap: 2rem;
    }

    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 15px;
      position: relative;
      padding: 0.25rem 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--neon-green);
      transition: width 0.25s ease, left 0.25s ease;
    }

    .nav-links a:hover {
      color: var(--neon-green);
    }

    .nav-links a:hover::after {
      width: 100%;
      left: 0;
    }

    .btn-capsule {
      border-radius: var(--btn-radius);
      padding: 0.6rem 1.8rem;
      font-weight: 600;
      font-size: 14px;
      letter-spacing: 0.3px;
      border: 1px solid var(--neon-green);
      background: transparent;
      color: var(--neon-green);
      transition: var(--transition-smooth);
      cursor: pointer;
      display: inline-block;
      text-align: center;
      white-space: nowrap;
    }

    .btn-capsule:hover {
      background: var(--neon-green);
      color: var(--primary-bg);
      box-shadow: 0 0 28px rgba(0,240,168,0.5);
      border-color: var(--neon-green);
    }

    .btn-primary-glow {
      background: var(--neon-green);
      color: #0A0E27;
      border: none;
      font-weight: 700;
      box-shadow: 0 0 25px rgba(0,240,168,0.4);
    }

    .btn-primary-glow:hover {
      background: #33FFB9;
      box-shadow: 0 0 40px rgba(0,240,168,0.7);
      color: #0A0E27;
    }

    .btn-outline-white {
      border: 1px solid rgba(255,255,255,0.5);
      color: white;
      background: transparent;
    }

    .btn-outline-white:hover {
      border-color: var(--neon-green);
      color: var(--neon-green);
    }

    /* 移动端导航 */
    .hamburger {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
    }

    /* hero */
    .hero {
      min-height: 90vh;
      background: radial-gradient(circle at 30% 40%, #1A1040 0%, #0A0E27 70%);
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }

    .hero-content {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
    }

    .hero-text {
      flex: 1 1 450px;
    }

    .hero-video-placeholder {
      flex: 1 1 450px;
      background: rgba(255,255,255,0.02);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 16px;
      aspect-ratio: 16/9;
      backdrop-filter: blur(8px);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 3rem;
      color: rgba(255,255,255,0.2);
      transition: var(--transition-smooth);
    }

    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      color: rgba(255,255,255,0.5);
      font-size: 1.5rem;
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% { opacity: 0.5; transform: translateX(-50%) translateY(0); }
      50% { opacity: 1; transform: translateX(-50%) translateY(6px); }
      100% { opacity: 0.5; transform: translateX(-50%) translateY(0); }
    }

    /* 通用section */
    section {
      padding: 100px 0;
    }

    .glass-card {
      background: var(--surface-glass);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--border-light);
      border-radius: var(--card-radius);
      padding: 2rem;
      transition: var(--transition-smooth);
    }

    .glass-card:hover {
      border-color: var(--border-active);
      box-shadow: 0 0 30px rgba(0,240,168,0.15), 0 8px 32px rgba(0,0,0,0.5);
      transform: translateY(-4px);
    }

    .icon-circle {
      font-size: 2rem;
      color: var(--neon-green);
      margin-bottom: 1rem;
    }

    .big-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--neon-green);
      line-height: 1.2;
    }

    /* 功能交替 */
    .feature-row {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 2.5rem;
      margin-bottom: 4rem;
    }

    .feature-img {
      flex: 1 1 300px;
      border-radius: 12px;
      overflow: hidden;
      border: 1px solid rgba(255,255,255,0.1);
    }

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

    /* FAQ */
    .accordion-item {
      background: rgba(255,255,255,0.02);
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: 12px;
      margin-bottom: 0.8rem;
    }

    .accordion-title {
      font-weight: 600;
      color: white;
      padding: 1rem 1.5rem;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 0.8rem;
    }

    .accordion-content {
      padding: 0 1.5rem 1.2rem;
      color: var(--text-body);
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      h1 { font-size: 36px; }
      section { padding: 70px 0; }
    }

    @media (max-width: 640px) {
      h1 { font-size: 30px; }
      h2 { font-size: 26px; }
      .hero { min-height: 70vh; }
      .feature-row { flex-direction: column; }
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 24px;
    }

    .grid-2 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }

    footer {
      background: #0A0E27;
      color: var(--text-muted);
      padding: 3rem 0 1.5rem;
    }