bootstrap 4 top 0 class code example

Example 1: bootstrap position

<div class="position-static">...</div>
<div class="position-relative">...</div>
<div class="position-absolute">...</div>
<div class="position-fixed">...</div>
<div class="position-sticky">...</div>

Example 2: mb-0

<p class="mb-4">Lorem ipsum</p>