yle">
      #button {
        background-color: var(--paper-red-100);
        width: 150px;
      }

      #exception {
        font-size: 1.0em;
        margin: 1em;
        white-space: pre-wrap;
        overflow: auto;
      }

      #expanded {
        border-style: solid;
        border-width: 0.25px;
        font: 0.75rem 'Roboto Monospace', monospace;
        background-color: var(--paper-grey-100);
        margin-top: 1em;
      }
    </style>

    <template is="dom-if" if="[[exception]]">
      <p 