A example on how to separate content vertically down the page.
Code:
<div class="container border border-dark">
<div class="row">
<div class="col">
<br>
<br>
<br>
<br>
content
<br>
<br>
<br>
<br>
<br>
</div>
</div>
<div class="row bg-secondary text-white">
<div class="col">
<br>
<br>
<br>
<br>
content
<br>
<br>
<br>
<br>
<br>
</div>
</div>
<div class="row">
<div class="col">
<br>
<br>
<br>
<br>
content
<br>
<br>
<br>
<br>
<br>
</div>
</div>
<div class="row bg-dark text-white">
<div class="col">
<br>
<br>
<br>
<br>
content
<br>
<br>
<br>
<br>
<br>
</div>
</div>
</div>