Container queries (size)✓Baseline · Widely available

.card-list {
  container-type: inline-size;
  container-name: cards;
}

/* Lay the card out horizontally once its container is wide enough */
@container cards (min-width: 400px) {
  .card {
    display: grid;
    grid-template-columns: 120px 1fr;
  }
}

@supports (container: initial) {
  /* styles that rely on container */
}

/* or in JavaScript */
if (CSS.supports("container", "initial")) {
  // use it
}