Clearing Rows with CSS Grid

Today I completed a fun little challenge using CSS Grid.

The goal was to update a layout that relied on container elements and flexbox.

<div class="cards">
  <pfe-card id="a-1">...</pfe-card>
  <pfe-card id="a-2">...</pfe-card>
  <pfe-card id="a-3">...</pfe-card>
  <pfe-card id="a-4">...</pfe-card>
</div>
<div class="cards">
  <pfe-card id="b-1">...</pfe-card>
  <pfe-card id="b-2">...</pfe-card>
  <pfe-card id="b-3">...</pfe-card>
  <pfe-card id="b-4">...</pfe-card>
</div>

.cards {
  display: flex;
  flex-flow: row wrap;
}

.cards > * {
  margin-bottom: 15px;
  margin-right: 15px;
  min-width: 200px;
  width: calc(25% - 32px);
}

My first step was to remove the container elements and 'lift up' the flex properties into the grid container

<pfe-card id="a-1">...</pfe-card>
<pfe-card id="a-2">...</pfe-card>
<pfe-card id="a-3">...</pfe-card>
<pfe-card id="a-4">...</pfe-card>
<pfe-card id="b-1">...</pfe-card>
<pfe-card id="b-2">...</pfe-card>
<pfe-card id="b-3">...</pfe-card>
<pfe-card id="b-4">...</pfe-card>

:host {
  display: grid;
  grid-template-columns: repeat(
    auto-fill,
    minmax(
      200px,
      calc(25% - 32px)));
  grid-auto-rows: max-content;
  gap: 15px;
}

This did most of the job on its own, but there was one issue: in the original layout, card b-1 appeared in a new 'row' below the first set of cards. How could I emulate this 'row-clearing' behaviour? Using grid-column, I specified the position of the first card in the second set: