“JavaScript QuerySelector - по классу” Ответ

JavaScript QuerySelector - по классу

<div class="box">
  <h3>Heading inside the 1st box.</h3>
  <p>This is a paragraph inside the <b>1st box</b>.</p>
</div>
<div class="box">
  <h3>Heading inside the 2nd box.</h3>
  <p>This is a paragraph inside the <b>2nd box</b>.</p>
</div>

<script>
  // selecting element by class
  let element = document.querySelector(".box");

  element.style.background = "lightgreen";
</script>