body {
      margin: 0;
      padding: 0;
      font-family: 'Segoe UI', sans-serif;
      display: flex;
      align-items: center;
      justify-content: center;
      height: 100vh;
      background: #f0f2f5;
    }

    .loader, .success {
      text-align: center;
    }

    .spinner {
      border: 8px solid #e0e0e0;
      border-top: 8px solid #28a745;
      border-radius: 50%;
      width: 80px;
      height: 80px;
      animation: spin 1s linear infinite;
      margin: 0 auto 20px;
    }

    @keyframes spin {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }

    .hidden {
      display: none;
    }

    .checkmark {
      font-size: 60px;
      color: #28a745;
      animation: pop 0.4s ease;
    }

    @keyframes pop {
      0% { transform: scale(0); opacity: 0; }
      100% { transform: scale(1); opacity: 1; }
    }

    h1 {
      color: #333;
    }

    p {
      color: #666;
    }

    .button {
      display: inline-block;
      margin-top: 30px;
      padding: 12px 25px;
      background-color: #28a745;
      color: white;
      text-decoration: none;
      border-radius: 8px;
      font-weight: bold;
    }

    .button:hover {
      background-color: #218838;
    }