SOURCE

<div class="wrapper">
  <div class="one item">One</div>
  <div class="two item">Two</div>
  <div class="three item">Three</div>
  <div class="four item">Four</div>
  <div class="five item">Five</div>
  <div class="six item">Six</div>
</div>

.wrapper {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-gap: 20px;
  grid-auto-rows: minmax(100px, auto);
}
.one {
  grid-column-start: 1;
  grid-column-end: 2;
  background: #19CAAD;
}
.two { 
  grid-column-start: 2;
  grid-column-end: 4;
  grid-row-start: 1;
  grid-row-end: 2;
  /*   如果有重叠，就使用 z-index */
  z-index: 1;
  background: #8CC7B5;
}
.three {
  grid-column-start: 3;
  grid-column-end: 4;
  grid-row-start: 1;
  grid-row-end: 4;
  background: #D1BA74;
}
.four {
  grid-column-start: 1;
  grid-column-end: 2;
  grid-row-start: 2;
  grid-row-end: 5;
  background: #BEE7E9;
}
.five {
  grid-column-start: 2;
  grid-column-end: 2;
  grid-row-start: 2;
  grid-row-end: 5;
  background: #E6CEAC;
}
.six {
  grid-column: 3;
  grid-row: 4;
  background: #ECAD9E;
}