Represents a container that utilizes a flexible layout.
<px-flex-panel orientation="horizontal" style="height: 35px;">
<div class="blue">Left</div>
<div class="red" style="flex: 1;">Center</div>
<div class="green">Right</div>
</px-flex-panel>
<px-flex-panel style="height: 100px;">
<div class="blue">Left</div>
<div class="red" style="flex: 1;">Center</div>
<div class="green">Right</div>
</px-flex-panel>