Bootstrap CSS class .align-self-*-center

<div class="align-self-center">Aligned flex item</div>

<!-- responsive variations -->
<div class="align-self-sm-center">Aligned flex item</div>
<div class="align-self-md-center">Aligned flex item</div>
<div class="align-self-lg-center">Aligned flex item</div>
<div class="align-self-xl-center">Aligned flex item</div>