make Bootstrap 4 responsive cards code example

Example 1: card bootstrap 4

<div class="card" style="width:400px">
    <img class="card-img-top" src="img_avatar1.png" alt="Card image" style="width:100%">
    <div class="card-body">
      <h4 class="card-title">John Doe</h4>
      <p class="card-text">Some example text some example text. John Doe is an architect and engineer</p>
      <a href="#" class="btn btn-primary">See Profile</a>
    </div>
  </div>

Example 2: Bootstrap 4 Cards

<div class="card">
  <div class="card-body">Basic card</div>
</div>