// brief.typ — mopac-pdf "brief" template: dense 1-3 page executive brief.
// No title page, no TOC; compact type, tight tables, classification footer.
#let brief(
  title: "Untitled",
  subtitle: "",
  author: "",
  date: "",
  classification: "",
  doc,
) = {
  let accent = rgb("#1f4e79")
  let ink = rgb("#1a1a1a")

  set page(
    paper: "a4",
    margin: (top: 1.9cm, bottom: 2.0cm, x: 1.9cm),
  )
  set text(font: "Libertinus Serif", size: 10pt, fill: ink, lang: "en")
  set par(justify: true, leading: 0.55em, spacing: 0.9em)
  set heading(numbering: none)
  show heading: set block(above: 1.05em, below: 0.5em)
  show heading.where(level: 1): it => {
    text(size: 13.5pt, fill: accent, weight: "bold")[#it]
    v(-0.5em)
    line(length: 100%, stroke: 0.8pt + accent)
    v(0.2em)
  }
  show heading.where(level: 2): it => text(size: 11pt, weight: "bold")[#it]
  show heading: it => {
    if it.level >= 3 { text(size: 10pt, weight: "bold", style: "italic")[#it] } else { it }
  }
  // Dense tables: the body renderer already styles headers; shrink body text.
  show table: set text(size: 9pt)
  show raw: set text(size: 8.5pt)

  set page(footer: context {
    set text(size: 8pt, fill: luma(95))
    grid(
      columns: (1fr, auto, 1fr),
      align: (left + horizon, center + horizon, right + horizon),
      text(style: "italic")[#title],
      counter(page).display(),
      if classification != "" [#classification],
    )
  })

  // Title block (no separate page).
  block(above: 0em, below: 1.1em)[
    #set text(size: 10pt)
    #grid(
      columns: (1fr, auto),
      align: (left + horizon, right + horizon),
      [
        #text(size: 19pt, weight: "bold", fill: ink)[#title]
        #if subtitle != "" [
          #v(0.25em)
          #text(size: 11pt, fill: luma(80))[#subtitle]
        ]
        #v(0.3em)
        #text(size: 9.5pt, fill: luma(70))[
          #if author != "" [#author]
          #if author != "" and date != "" [#h(1.2em)]
          #if date != "" [#date]
        ]
      ],
      if classification != "" [
        #box(stroke: 0.8pt + accent, inset: (x: 0.55em, y: 0.35em), radius: 2pt)[
          #text(size: 8.5pt, fill: accent, tracking: 1.5pt, weight: "semibold")[#upper(classification)]
        ]
      ],
    )
    #v(0.5em)
    #line(length: 100%, stroke: 1.4pt + accent)
  ]

  doc
}