JSFiddle - React, Tailwind, and code Playground

HTML

<h2 data-number="2">
  步驟...
</h2>

CSS

h2:before {
  content: attr(data-number);
  display: inline-block;
  /* customize below */
  font-size: 1em;
  margin-right: 0.6em;
  width: 1.6em;
  line-height: 1.6em;
  text-align: center;
  border-radius: 50%;
  color: #FFF;
  background: #F77621;
}