<ol class="custom-counter">
  <li>This is the first item</li>
  <li>This is the second item</li>
  <li>This is the third item</li>
  <li>This is the fourth item</li>
  <li>This is the fifth item</li>
  <li>This is the sixth item</li>
</ol
body {
  font-size: 1.2em;
  font-family: "Helvetica Neue", Helvetica, sans-serif;
  margin: 50px;
}

.custom-counter {
  margin: 0;
  padding: 0;
  list-style-type: none;
}

.custom-counter li {
  counter-increment: step-counter;
  margin-bottom: 10px;
}

.custom-counter li::before {
  content: counter(step-counter);
  margin-right: 5px;
  font-size: 80%;
  background-color: rgb(0,200,200);
  color: white;
  font-weight: bold;
  padding: 3px 8px;
  border-radius: 3px;
}

External CSS

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External JavaScript

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