<!-- Quirks mode -->
<style>
#a {
  columns: 15;
}
#b {
  grid-template: repeat(auto-fill, fit-content(3%)) / 1em;
}
*:only-of-type {
  white-space: pre-line;
  margin-bottom: 76%;
}
*:last-of-type {
  float: inline-end;
  display: flow;
}
</style>
<section id="a">
<main>
<audio controls=""></audio>
A
<pre>
</main>
<b>
<details open="">
AAAAAAAAAAAAAAA
<summary>
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
</b>
<bdi id="b">
<small>
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
<button></button>
</bdi>
</html>