<!DOCTYPE html>
<style>
ul {
  border: solid 1px green;
  background-color: green;
  font-family: Ahem;
  font-size: 10px;
}
li {
  color: transparent;
}
</style>
<ul><li><div style="line-height: 0px">collapsed block but non-collapsed list item</div></li></ul>
<ul><li style="line-height: 0px"><div>both block and list item are collapsed</div></li></ul>
<ul><li><div style="line-height: 10px">testing</div></li></ul>
<ul><li style="line-height: 10px">testing<div></div></li></ul>
