textarea>
        <fieldset>
          <legend>Options</legend>
          <h2>Swing Parameters</h2>
          <label>Swing:
            <input class="swing-value" type="number" min="50" max="75" step="1" value="60">
          </label>
        </fieldset>
      </section>

      <section class="output">
        <h2>Output</h2>
        <div id="audio"></div>
        <div id="warnings"></div>
        <div id="paper" class="visible-background"></div>
      </section>

      <section class="explanation">
       