For this example, we will use bootstrap cards, you can customize the html code according to your needs.

file: shotcodes/card.html

<div class="card text-bg-light mb-3">
  <div class="card-header"><h2>{{ .Get 0 }}</h2></div>
  <div class="card-body">
    <p class="card-text">{{ .Inner }}</p>
  </div>
</div>

Insert below code in your post

{{% card "Header" %}}
Some quick example text to build on the card title and make up the bulk of the card's content.
{{% /card %}}

Output:

Some quick example text to build on the card title and make up the bulk of the card's content.

From here you can style the shortcode.