Demo: CSS place-items

<div class='grid-container'>
  <div class='grid-item'>1</div>
  <div class='grid-item'>2</div>
  <div class='grid-item'>3</div>
  <div class='grid-item'>4</div>
</div>

.grid-container {
  display: grid;
  grid-template-columns: repeat(2, 100px);
  grid-template-rows: repeat(2, 100px);
  place-items: center;
  gap: 10px;
  background-color: #f0f0f0;
  padding: 20px;
}

.grid-item {
  background-color: #4CAF50;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 24px;
  border-radius: 5px;
}

// No JavaScript required for this demo