10px 0;
    }
    footer button {
      background:#0066b3;
      color:white;
      border: 0;
      border-radius: 5px;
      padding:8px;
    }
    footer button.selected {
      font-weight:bold;
    }
    </style>

    <script>
      document.querySelectorAll('footer button').forEach(button => {
        button.addEventListener('click',(event) => {

          document.querySelectorAll('footer button').forEach(button => {
            button.classList.remove('selected');
          });

          var examp