<section>
  <h1>1. No CSS applied</h1>
  <div>2. Descendant Selector</div>
  <h2>3. No CSS applied</h2>
  <div>4. Descendant Selector</div>
  <h3>5. No CSS applied</h3>
  <div>6. Descendant Selector</div>
  <article>
      <div>7.1 Descendant Selector</div>
  </article>
  <span>
      <div>7.2 Descendant Selector</div>
  </span>
  <h1>8. No CSS applied</h1>
  <div>9. Descendant Selector</div>
</section>

section div {
  color: red;
}