counter-set CSS property

counter-set: none;

counter-set: chapter-count 0;

counter-set: chapter-count;

counter-set: chapter-count 5;

counter-set: chapter-count -5;

<section class="default-example" id="default-example">
  <div class="transition-all" id="chapters">
    <h1>Alice's Adventures in Wonderland</h1>
    <h2>Down the Rabbit-Hole</h2>
    <h2 id="example-element">The Pool of Tears</h2>
    <h2>A Caucus-Race and a Long Tale</h2>
    <h2>The Rabbit Sends in a Little Bill</h2>
  </div>
</section>

#default-example {
  text-align: left;
  counter-set: chapter-count;
}

#example-element {
  background-color: #37077c;
  color: white;
}

h2 {
  counter-increment: chapter-count;
  font-size: 1em;
}

h2::before {
  content: "Chapter " counter(chapter-count) ": ";
}

/* Set "my-counter" to 0 */
counter-set: my-counter;

/* Set "my-counter" to -1 */
counter-set: my-counter -1;

/* Set "counter1" to 1, and "counter2" to 4 */
counter-set: counter1 1 counter2 4;

/* Cancel any counter that could have been set in less specific rules */
counter-set: none;

/* Global values */
counter-set: inherit;
counter-set: initial;
counter-set: revert;
counter-set: revert-layer;
counter-set: unset;

h1 {
  counter-set: chapter section 1 page;
  /* Sets the chapter and page counters to 0,
     and the section counter to 1 */
}