css样式

grid实现

.item-container {
  display: flex;
  justify-content: center;
  align-items: center;
  border-radius: 12px;
}
/* grid布局 */
.grid-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px 10px;
}
.grid-item {
  background-color: #56ab2f;
  color: #a1c4fd;
  height: 108px;
}

flex+css伪类

.grid-container {
  display: flex;
  flex-wrap: wrap;
}
.grid-item {
  background-color: #56ab2f;
  color: #a1c4fd;
  height: 108px;
  width: calc((100% - 20px) / 3);
  margin-right: 10px;
  margin-top: 10px;
}
.grid-item:nth-child(3n) {
  margin-right: 0;
}

html

<div class="grid-container">
    <div class="grid-item item-container">
      1
    </div>
    <div class="grid-item item-container">
      2
    </div>
    <div class="grid-item item-container">
      3
    </div>
    <div class="grid-item item-container">
      4
    </div>
    <div class="grid-item item-container">
      5
    </div>
    <div class="grid-item item-container">
      6
    </div>
    <div class="grid-item item-container">
      7
    </div>
    <div class="grid-item item-container">
      8
    </div>
    <div class="grid-item item-container">
      9
    </div>
    <div class="grid-item item-container">
      10
    </div>
</div>