<div class="grid">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
  <div>5</div>
  <div>6</div>
  <div class="placed">Placed</div>
</div>

body {
  padding: 50px;
  font: 1em Helvetica Neue, Helvetica, Arial, sans-serif;
}

.grid {
  border: 5px solid rgb(111,41,97);
  display: grid;
  grid-template-columns: repeat(5, 100px);
  grid-auto-rows: 5em;
  inline-size: 500px;
}

.grid > * {
  background-color: rgba(111,41,97,.4);
  border-radius: 5px;
  padding: 10px;
}

.grid > .placed {
  background-color: orange;
  grid-row: 1 / -1; /* the end line is in the implicit grid so -1 does not resolve to it*/
}