<!DOCTYPE html> <!-- webkit-test-runner [ LayoutFormattingContextEnabled=true LayoutFormattingContextIntegrationEnabled=false ] -->
<style>
.container {
  float: left;
  background-color: green;
  color: green;
  font-size: 20px;
  font-family: Ahem;
}

.divider {
  clear: left;
}

span {
  vertical-align: middle;
}
</style>

<div class=container>XX<span>XX</span></div>
<div class=divider></div>
<div class=container>XX<span style="font-size: 10px;">XX</span></div>
<div class=divider></div>
<div class=container>XX<span style="font-size: 50px;">XX</span></div>