bootstrap felx code example
Example 1: bootstrap justify-content-center for md
<div class="row justify-content-md-center"></div>
Example 2: ustify-content: flex-end; bootstrap
<div class="d-flex justify-content-end">...</div>
<div class="row justify-content-md-center"></div>
<div class="d-flex justify-content-end">...</div>