body {
      font-family: monospace;
      background: #111;
      color: #eee;
      padding: 2em;
    }
    textarea {
      width: 100%;
      height: 100px;
      font-size: 1em;
      margin-bottom: 1em;
      background: #222;
      color: #0f0;
      border: none;
      padding: 1em;
    }
    button {
      padding: 0.5em 1em;
      font-size: 1em;
      margin-right: 1em;
      background: #333;
      color: #fff;
      border: none;
      cursor: pointer;
    }
    #output {
      white-space: pre-wrap;
      background: #222;
      padding: 1em;
      border: 1px solid #444;
      margin-top: 1em;
    }