olid thick; padding: 1em; margin: 1em; font-size: large; font-weight: bold; background: yellow;">
        Do not open this HTML file directly; to test,
        run <code>npm install</code> and instead
        serve <code>dist/index.html</code> from an http server.
      </div>
    <% } %>
    <form style="display:flex" onSubmit="event.preventDefault(); render()">
      <textarea id="formula" style="flex-grow: 1">\int_0^1 x^2 \, dx</textarea>
      <button type="submit">Render</button>
    </form>
    <h2>Re