
  display: grid;
  width: 100px;
  background: red;
}
.item {
  grid-row: 2 / span 1;
  background: green;
  width: 100px;
  height: 100px;
  position: relative;
  top: -32px; /* To move this item up to cover the first row */
}
</style>

<!--
  Flexible row track sizes are resolved in two passes:

  The first pass:
   - The only grid item has a max-content height of 100px, which is also the
     hypothetical fr size.
   - Initially, each flexible track (0.4fr) is given a hypothetical size of
     100px * 0