div vertical align middle bootstrap code example
Example 1: bootstrap vertical align
<div class="d-flex align-items-start">...</div>
<div class="d-flex align-items-end">...</div>
<div class="d-flex align-items-center">...</div>
<div class="d-flex align-items-baseline">...</div>
<div class="d-flex align-items-stretch">...</div>
Example 2: bootstrap center text vertically
<div class=”row”>
<div class=”col-6 align-self-center”>
<div class=”card card-block”>
Center
</div>
</div>
</div>