Write an article with three reading depths

Using [SOURCE PACK], produce one article on [TOPIC] with three nested reading depths. Begin with a 60-word answer, continue with a 400-word explanation and end with a deeper evidence section. The shorter layers must never contradict or oversimplify the full account. Add source notes to concrete claims and a 'what would change this' paragraph. Use clear headings and avoid repeating whole sentences across layers. If a data point is missing, write the uncertainty explicitly. Return a table showing which questions each depth answers; do not fabricate a quote or statistic.