y: monospace;
  font-size: 1ch;
  content: 'text';
}

</style>

<div class="container before"></div>
<div class="container after"></div>
<div class="container first-letter">text</div>
<div class="container first-line">text</div>
<li class="container marker"></li>

<script>
function parseFontSizeInPx(element, pseudoElement) {
  const value = getComputedStyle(element, pseudoElement).fontSize;
  if (!value.endsWith('px'))
    return NaN;
  return parseFloat(value);
}

const testCases = ['before', 'after', 'fir