如何将列与网格对齐并使最后一行居中？

<div class="grid-container">
  <div class="grid-item">Item 1</div>
  <div class="grid-item">Item 2</div>
  <div class="grid-item">Item 3</div>
  <div class="grid-item">Item 4</div>
  <div class="grid-item">Item 5</div>
  <div class="grid-item">Item 6</div>
</div>

.grid-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  justify-items: center;
  align-content: center;
  grid-gap: 10px;
}

.grid-item {
  background-color: #ccc;
  padding: 10px;
  text-align: center;
}