:root {
      --primary: #2563eb;
      --secondary: #10b981;
      --dark: #111827;
      --gray: #6b7280;
      --light-bg: #f9fafb;
    }

    body {
      margin: 0;
      font-family: 'Inter', sans-serif;
      background: var(--light-bg);
      color: var(--dark);
      line-height: 1.6;
    }

    header {
      background: linear-gradient(145deg, #1e3a8a, #080c1a);
      color: white;
      padding: 80px 20px 50px;
      text-align: center;
    }

    header h1 {
      font-size: 2.5rem;
      margin-bottom: 10px;
    }

    header h2 {
      font-size: 1.2rem;
      font-weight: 400;
      color: #d1d5db;
      margin-bottom: 30px;
    }

    #countdown {
      font-size: 3rem;
      font-weight: 700;
      color: var(--secondary);
    }

    .section {
      padding: 60px 20px;
      max-width: 1000px;
      margin: auto;
    }

    .section h3 {
      font-size: 1.8rem;
      margin-bottom: 30px;
      text-align: center;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 20px;
    }

    .card {
      background: white;
      border-radius: 12px;
      box-shadow: 0 8px 16px rgba(0,0,0,0.05);
      padding: 24px;
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }

    .card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 20px rgba(0,0,0,0.1);
    }

    .card strong {
      display: block;
      margin-bottom: 8px;
      font-weight: 600;
      color: var(--primary);
    }

    .cta {
      text-align: center;
      margin-top: 60px;
    }

    .cta a {
      background: var(--primary);
      color: white;
      padding: 14px 28px;
      font-weight: bold;
      border-radius: 8px;
      text-decoration: none;
      font-size: 1rem;
      transition: background 0.3s;
    }

    .cta a:hover {
      background: #1e3a8a;
    }

    footer {
      text-align: center;
      padding: 40px 20px;
      font-size: 0.9rem;
      color: var(--gray);
    }

    @media (max-width: 600px) {
      header h1 {
        font-size: 2rem;
      }

      #countdown {
        font-size: 2.5rem;
      }
    }

    .architecture {
      max-width: 700px;
    }

    .center-box {
      text-align: center
    }

    .qr-code {
      max-width: 200px;
    }