body {
      margin: 0;
      font-family: Arial, sans-serif;
      color: #fff;
      text-align: center;
      background: linear-gradient(270deg, red, orange, yellow, green, cyan, blue, violet);
      background-size: 1400% 1400%;
      animation: rainbow 30s ease infinite;
    }

    @keyframes rainbow {
      0% { background-position: 0% 50%; }
      50% { background-position: 100% 50%; }
      100% { background-position: 0% 50%; }
    }

    h1 {
      margin-top: 0;
      padding-top: 20px;
    }

    section {
      display: none;
      padding: 30px;
      max-width: 800px;
      margin: 40px auto;
      background: rgba(0,0,0,0.6);
      border-radius: 12px;
      box-shadow: 0 0 20px rgba(0,0,0,0.8);
    }

    section.active {
      display: block;
    }

    h2 {
      margin-top: 0;
    }

    p {
      margin: 12px 0;
    }

    a {
      color: #ffea00;
      text-decoration: none;
      font-weight: bold;
    }

    a:hover {
      text-decoration: underline;
    }