<div class="d-flex bg-secondary text-white p-1">
<div class="p-3 w-50 flex-shrink-1 flex-xxl-shrink-0 bg-primary">1</div>
<div class="p-3 w-50 bg-info">2</div>
<div class="p-3 w-50 bg-success">3</div>
<div class="p-3 w-50 bg-primary">4</div>
<div class="p-3 w-50 bg-success">3</div>
</div>
You don't need to remember all CSS classes. Just use the Bootstrap Editor instead.