.container {
   display: grid;
   grid-template-columns: 40px [line2] 50px auto [line4] 50px 40px;
   grid-template-rows: [row1-start] 35px 50px 30px;

   border:1px solid #ddd;
   margin-top:10px;
}

.child {
  padding: 5px;
  background: #d4e6f1;
  margin: 5px;
}

.child-1 {
  grid-column-start: line2;
  grid-column-end: line4;
  grid-row-start: row1-start;
  grid-row-end: 3;
 }