#let signature(at: none, date: none, ..signatories) = {
  let answer = [ _Fait à_ ]

  if at == none {
    answer += box(width: 30%, stroke: (bottom: (thickness: 0.5pt, dash: "dotted")), none)
  } else {
    answer += text(weight: "bold", at)
  }

  answer += [, _le_ ]

  if date == none {
    answer += box(width: 30%, stroke: (bottom: (thickness: 0.5pt, dash: "dotted")), none)
  } else {
    answer += text(weight: "bold", date.display("[day]/[month]/[year]"))
  }

  let names-grid-construction(s) = text(weight: "bold", s.at(0)) + "\n" + text(style: "italic", s.at(1))
  let sign-grid-construction(s) = if (s.len() >= 3) { align(left, pad(5pt, s.at(2))) } else { [] }
  let n = signatories.pos().map(names-grid-construction)
  let s = signatories.pos().map(sign-grid-construction)

  answer += grid(columns: (50%, 50%), rows: (auto, 70pt), ..n, ..s)
  
  block(answer, breakable: false)
}

#let template(body, title: "Title", subtitle: "Subtitle", logo: none, watermark: "", size: 10pt) = {
  // Document appearence
  set document(title: title + " ‑ " + subtitle)
  set page(columns: 2, margin: 1.5cm, numbering: "1/1")
  set page(background: rotate(-55deg, text(size: 50pt, rgb(0, 0, 0, 30))[*#watermark*]))

  set text(font: "New Computer Modern", lang: "fr", size: size)

  set par(justify: true, first-line-indent: (amount: 1em, all: true))

  set list(marker: sym.bar.h)

  set enum(numbering: "(i)")

  show link: l => [#text(underline(l), fill: color.blue)]

  // Style des titres
  let premier(.., last, format: "I") = numbering(format, last) + if last == 1 { super[er] }
  
  set heading(numbering: "I.1.I.", supplement: [])
  
  show heading.where(level: 1): it => [
    #align(center, block[
      #if it.numbering != none [
        Titre #context counter(heading).display(premier.with(format: "I"))
      ]
  
      #text(size: 0.9em, it.body)
      #line(length: 3cm)
      #v(1em)
    ])
  ]

  let articlecounter = counter("article")
  show heading.where(level: 2): it => {
    articlecounter.step()
    align(center, block[
      Article #context articlecounter.display(premier.with(format: "1")) #sym.bar.h #text(size: 0.9em, style: "italic", it.body)
    ])
  }
  
  show heading.where(level: 3): it => [
    #context counter(heading).display(premier.with(format: "I")) #sym.bar.h #if it.body != [] { text(size: 0.9em, style: "italic", [#it.body.]) }
  ]

  show ref: it => {
    let el = it.element
    let article = articlecounter.at(el.location()).at(0, default: none)
    let par = counter(heading).at(el.location()).at(2, default: none)
    if el != none and el.func() == heading and article != none {
      // Override heading references.
      if (par == none) {
        link(el.location(), numbering(
          "1",
          article + 1,
        ))
      } else {
        link(el.location(), numbering(
          "1.I",
          article,
          par
        ))
      }
    } else {
      // Other references as usual.
      it
    }
  }

  // Start of the document
  place(
    top + center,
    scope: "parent",
    float: true,
    align(center)[
      #if logo != none {
        if type(logo) == str {
          image(logo, alt: "Logo", height: 5em)
        } else if type(logo) == content {
          logo
        } else {
          panic("logo is not of type str or content")
        }
      }
    
      #text(size: 2.5em, weight: "extrabold")[#title]
    
      #text(size: 1.5em)[#subtitle]
  
      #v(1cm)
    ],
  )

  body
}