bootstrap 4 vertical align div content to center. code example
Example 1: bootstrap center align columns
<!-- Center columns in a Row -->
<div class="row d-flex justify-content-center text-center">
<div class="col-4">
</div>
<div class="col-4">
</div>
<div class="col-4">
</div>
</div>
Example 2: bootstrap column vertical align
<span class="align-baseline">baseline</span>
<span class="align-top">top</span>
<span class="align-middle">middle</span>
<span class="align-bottom">bottom</span>
<span class="align-text-top">text-top</span>
<span class="align-text-bottom">text-bottom</span>