<!DOCTYPE HTML>
<style>
#container {
display: flex;
align-items: flex-start;
width: 200px;
height: 300px;
background-color: red;
}
.item {
background-color: green;
border: solid thin blue;
width: 100px;
height: 300px;
}
</style>
<p style="height: 20px">There should be no invalidations because align-content style change causes no visual change.</p>
<div id="container">
<div class="item"></div>
<div class="item"></div>
</div>