<title>::first-letter and overflow</title>
<style>

div {
  height: 8em; width: 5em;
  padding: 3px;
  background: yellow; color: black;
  line-height: 1.0;
}
div::first-letter { font-size: 1.2em }

</style>

<div>Hello world, testing, testing, testing, testing</div>