chromium/third_party/blink/web_tests/external/wpt/css/css-overflow/line-clamp/reference/line-clamp-auto-034-ref.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Reference</title>
<style>
.clamp {
  display: flow-root;
  font: 16px / 32px serif;
  white-space: pre;
  padding: 0 4px;
  background-color: yellow;
}
.ifc {
  display: flow-root;
  background-color: orange;
}
</style>

<div class="clamp">Line 1
Line 2
Line 3
Line 4
<div class="ifc">Line 5
Line 6</div></div>