body {
    background-color: #f4f4f4;
    font-family: Arial, sans-serif;
}
  
 header {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px 0;
}
  
 button {
    background-color: #4CAF50;
    color: white;
    padding: 10px;
    border: none;
    cursor: pointer;
}