Pure CSS Credit Card Type Icon

<h1>Pure CSS Credit Card Type Icon</h1>
<div class="container">
  <h2>Placeholder</h2>
  <div class="card-type"></div>
  <hr />
  <ul>
    <li><h3>Visa</h3><div class="card-type visa"></div>
    <li><h3>Mastercard</h3><div class="card-type mastercard"></div>
    <li><h3>American Express</h3><div class="card-type amex"></div>
    <li><h3>Discover</h3><div class="card-type discover"></div>
  </ul>
</div>