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

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

#poem[
  #block[
    “The Lion and the Unicorn were fighting for the crown: \
    The Lion beat the Unicorn all round the town. \
    Some gave them white bread, some gave them brown; \
    Some gave them plum-cake and drummed them out of town.”
  ]
]