class bootstrap center code example
Example 1: align items center bootstrap
<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 col center content
<div class="row">
<div class="col-4 d-flex justify-content-center text-center">
// for image and text
</div>
</div>
Example 3: bootstrap center
<div class="row h-100">
<div class="col-sm-12 my-auto">
<div class="card card-block w-25">Card</div>
</div>
</div>