.wrapper {
  display: grid;
  grid-template-columns: [main-start] 1fr [content-start] 1fr [content-end] 1fr [main-end];
  grid-template-rows: [main-start] 100px [content-start] 100px [content-end] 100px [main-end];
}

.box1 {
  grid-column-start: main-start;
  grid-row-start: main-start;
  grid-row-end: main-end;
}

.box2 {
  grid-column-start: content-end;
  grid-row-start: main-start;
  grid-row-end: content-end;
}

.box3 {
  grid-column-start: content-start;
  grid-row-start: main-start;
}

.box4 {
  grid-column-start: content-start;
  grid-column-end: main-end;
  grid-row-start: content-end;
}

.wrapper {
  display: grid;
  grid-template-columns: repeat(6, [col1-start] 1fr [col2-start] 3fr);
}

.item1 {
  grid-column: col1-start / col2-start 2
}

.item2 {
  grid-row: 2;
  grid-column: col1-start 2 / span 2 col1-start;
}