^Components Timeline

Use dl.timeline or wrap a <dl> with .has-timeline to style it as a vertical timeline — each <dd> gets a left border strip acting as the track:

dl.timeline,
.has-timeline > dl {
  dd {
    padding: 0.25rem 0 0.75rem 1rem;
    margin-block: 0;
    border-inline-start: 0.25rem solid var(--blades-timeline-border-color);
  }
}