css/css-flexbox/flex-item-vertical-align.html

<!DOCTYPE html>
<link href="support/flexbox.css" rel="stylesheet">
<title>CSS Flexbox: vertical-align on a flex item</title>
<link rel="help" href="https://drafts.csswg.org/css-flexbox/#flex-containers">
<link rel="help" href="https://drafts.csswg.org/css-inline/#propdef-vertical-align">
<link rel="match" href="reference/flex-item-vertical-align-ref.html">
<meta name="assert" content="vertical-align should have no effect on a flex item, i.e. flex items' content should not be shifted by the vertical-align.">

<style>
.flexbox {
  background-color: lightgrey;
}
#item1 {
  vertical-align: 10px;
}
#item3 {
  vertical-align: 30px;
}
</style>

<div class='flexbox'>
  <!-- flex item: block child -->
  <div id='item1'>block</div>
  <!-- flex item: anonymous block box around inline content -->
  anonymous item 2
  <!-- flex item: inline child -->
  <span id='item3'>item 3</span>
</div>