#let poem(content) = {
  set par(first-line-indent: 0em)

  align(center, block[
    #set align(left)
    #set block(breakable: false)
    #content
  ])
}

#poem[
  #block[
    “In summer, when the days are long, \
    Perhaps you'll understand the song:
  ]

  #block[
    In autumn, when the leaves are brown, \
    Take pen and ink, and write it down.”
  ]
]