 should not be reset and must not be reset.">

  <style>
  body
    {
      counter-reset: counter-of-span 17;
    }

    /*
    This creates a new counter identified as "counter-of-span"
    and initially sets such counter to 17 (an entirely
    arbitrary number)
    */

  div
    {
      contain: strict;
    }

  div > span
    {
      background-color: yellow;
      color: red;
      counter-increment: counter-of-span 3;
    }

    /*
    This increments the counter identified as "counter-of-span"
    of