What does this page log in a browser?

<div class="row"><span>A</span><span>Long label</span></div>
<style>
  .row { display: flex; gap: 20px; width: 300px; }
  .row span { box-sizing: border-box; flex: 1 1 0; min-width: 0; }
</style>
<script>
  const widths = [...document.querySelectorAll('span')]
    .map((item) => item.getBoundingClientRect().width);
  console.log(widths.join(','));
</script>