<!DOCTYPE html>
<html lang="en-US">
  <head>
    <meta charset="utf-8" />
    <title>Popup Virtual Keyboard</title>
    <link rel="stylesheet" href="../style.css" />
    <style>
      math-field {
        max-width: 320px;
        width: 100%;
        padding: 5px;
        margin: 10px 0 10px 0;
        border-radius: 5px;

        border: 1px solid var(--editable-border);
        background: var(--editable);
        color: var(--on-editable);
      }

      math-field::part(virtual-keyboard-toggle) {
     