/* roulang page: index */
:root {
      --cyan-neon: #00F0FF;
      --purple-deep: #7B2FFF;
      --dark-bg: #0A0E17;
      --surface-glass: rgba(255, 255, 255, 0.05);
      --border-glass: rgba(0, 240, 255, 0.2);
      --text-primary: #F8FAFC;
      --text-secondary: #CBD5E1;
      --text-muted: #94A3B8;
      --shadow-glow: 0 8px 32px rgba(0, 240, 255, 0.15);
      --radius-xl: 1.5rem;
      --radius-2xl: 2rem;
      --radius-full: 9999px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', sans-serif;
      background-color: var(--dark-bg);
      color: var(--text-primary);
      margin: 0;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .font-mono {
      font-family: 'Roboto Mono', 'DIN', 'Inter', monospace;
    }

    .glass-card {
      background: rgba(255, 255, 255, 0.05);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid rgba(0, 240, 255, 0.2);
      border-radius: var(--radius-xl);
      box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4), 0 0 12px rgba(0, 240, 255, 0.1);
      transition: all 0.25s ease;
    }

    .glass-card:hover {
      border-color: rgba(0, 240, 255, 0.5);
      box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), 0 0 20px rgba(0, 240, 255, 0.25);
      transform: translateY(-4px);
    }

    .btn-glow {
      background: linear-gradient(135deg, #00F0FF 0%, #7B2FFF 100%);
      border: none;
      color: #0A0E17;
      font-weight: 700;
      padding: 0.875rem 2.25rem;
      border-radius: var(--radius-full);
      box-shadow: 0 8px 24px rgba(0, 240, 255, 0.5);
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      letter-spacing: 0.5px;
      text-decoration: none;
    }

    .btn-glow:hover {
      box-shadow: 0 12px 32px rgba(0, 240, 255, 0.8);
      transform: translateY(-3px);
      color: #0A0E17;
    }

    .btn-ghost {
      background: transparent;
      border: 1.5px solid var(--cyan-neon);
      color: var(--cyan-neon);
      font-weight: 600;
      padding: 0.875rem 2.25rem;
      border-radius: var(--radius-full);
      backdrop-filter: blur(8px);
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      text-decoration: none;
    }

    .btn-ghost:hover {
      background: rgba(0, 240, 255, 0.1);
      border-color: #fff;
      color: #fff;
      transform: translateY(-2px);
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      background: linear-gradient(to right, #7B2FFF, #00F0FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1rem;
    }

    @media (min-width: 1024px) {
      .section-title {
        font-size: 3rem;
      }
    }

    .nav-link {
      color: #CBD5E1;
      font-weight: 500;
      transition: color 0.2s, text-shadow 0.2s;
      position: relative;
      padding: 0.5rem 0;
    }

    .nav-link:hover {
      color: #00F0FF;
      text-shadow: 0 0 8px rgba(0,240,255,0.6);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: #00F0FF;
      box-shadow: 0 0 12px #00F0FF;
      transition: width 0.3s;
    }

    .nav-link:hover::after {
      width: 100%;
    }

    /* Mega menu panel */
    .mega-panel {
      visibility: hidden;
      opacity: 0;
      transition: all 0.25s ease;
      transform: translateY(10px);
      pointer-events: none;
    }

    .mega-trigger:hover .mega-panel {
      visibility: visible;
      opacity: 1;
      transform: translateY(0);
      pointer-events: auto;
    }

    @media (max-width: 768px) {
      .mega-panel {
        display: none;
      }
    }

    /* mobile menu */
    #mobile-menu {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }

    #mobile-menu.open {
      max-height: 500px;
    }

    .stat-number {
      font-family: 'Roboto Mono', monospace;
      font-weight: 700;
    }