.container {
  width: 300px;
  height: 300px;
  border: 5px solid grey;
  margin: 10px auto;
  display: grid;
  grid-template-rows: repeat(3, 1fr);
  grid-template-columns: repeat(3, 1fr);
  div {
    border: 1px solid purple;
    //     行从第二根栅格线开始
    grid-row-start: 2;
    //     列从第二根栅格线开始
    grid-column-start: 2;
    //     行到第三根栅格线结束
    grid-row-end: 3;
    //     列到第三根栅格线结束
    grid-column-end: 3;

    background-color: purple;
    background-clip: content-box;
    padding: 10px;
  }
}