See what Prelum can produce¶

// An A4 invoice. Everything variable comes from the request's `data` object, which the renderer
// binds to `data` in a prelude it prepends to this file; `data.json` beside this template is the
// example payload.

#let currency(amount) = {
  let cents = calc.round(amount * 100)
  let minor = calc.rem-euclid(cents, 100)
  [#calc.div-euclid(cents, 100).#if minor < 10 [0#minor] else [#minor] #data.currency]
}

#let net = data.lines.map(line => line.quantity * line.unit_price).sum()
#let vat = net * data.vat_rate
#let total = net + vat

#set page(paper: "a4", margin: 2cm, numbering: none)
#set text(size: 10pt, font: "Libertinus Serif")

#grid(
  columns: (1fr, 1fr),
  align: (left, right),
  [
    #text(size: 16pt, weight: "bold")[#data.seller.name] \
    #data.seller.address.join("\n") \
    VAT #data.seller.vat
  ],
  [
    #text(size: 20pt, weight: "bold")[Invoice] \
    #data.number \
    Issued #data.date \
    Due #data.due
  ],
)

#v(1.5cm)

*Bill to* \
#data.customer.name \
#data.customer.address.join("\n")

#v(1cm)

#table(
  columns: (1fr, auto, auto, auto),
  align: (left, right, right, right),
  stroke: (x, y) => if y == 0 { (bottom: 0.6pt) } else { none },
  inset: 8pt,
  table.header[*Description*][*Quantity*][*Unit price*][*Amount*],
  ..data.lines
    .map(line => (
      line.description,
      [#line.quantity #line.unit],
      currency(line.unit_price),
      currency(line.quantity * line.unit_price),
    ))
    .flatten(),
)

#v(0.5cm)

#align(right)[
  #table(
    columns: (auto, auto),
    align: (left, right),
    stroke: none,
    inset: 6pt,
    [Net], currency(net),
    [VAT #calc.round(data.vat_rate * 100, digits: 1)%], currency(vat),
    [*Total*], [*#currency(total)*],
  )
]

{
  "number": "2026-0147",
  "date": "1 September 2026",
  "due": "1 October 2026",
  "seller": {
    "name": "Harbour Works Oy",
    "address": ["Rantakatu 12", "20100 Turku", "Finland"],
    "vat": "FI12345678"
  },
  "customer": {
    "name": "Northern Marina Ltd",
    "address": ["Satamatie 4", "90100 Oulu", "Finland"]
  },
  "currency": "EUR",
  "vat_rate": 0.255,
  "lines": [
    { "description": "Pontoon inspection", "quantity": 12, "unit": "h", "unit_price": 95.0 },
    { "description": "Underwater survey", "quantity": 1, "unit": "day", "unit_price": 1450.0 },
    { "description": "Condition report", "quantity": 1, "unit": "pcs", "unit_price": 380.0 }
  ]
}

// An 80x50 mm asset label. Page size belongs to the template, not to the request: the same
// endpoint returns this and the A4 invoice, and only the source decides which.

#set page(width: 80mm, height: 50mm, margin: 5mm)
#set text(size: 8pt)

#text(size: 13pt, weight: "bold")[#data.asset]

#v(1mm)
#line(length: 100%, stroke: 0.5pt)
#v(1mm)

#grid(
  columns: (auto, 1fr),
  row-gutter: 1.6mm,
  column-gutter: 3mm,
  [Site], [#data.site],
  [Inspected], [#data.inspected],
  [Next due], [*#data.next_due*],
  [Inspector], [#data.inspector],
)

{
  "asset": "Pontoon B-14",
  "site": "Northern Marina, Oulu",
  "inspected": "1 September 2026",
  "next_due": "1 March 2027",
  "inspector": "M. Laine"
}

// A multi-page report. Each section starts a page, so the document exercises page selection and
// ZIP archive output as well as ordinary single-file PDF output.

#set page(paper: "a4", margin: 2.5cm, numbering: "1 / 1")
#set text(size: 11pt)
#set par(justify: true)

#align(center)[
  #text(size: 18pt, weight: "bold")[#data.title] \
  #v(2mm)
  #data.site — #data.period
]

#for (index, section) in data.sections.enumerate() [
  #if index > 0 [#pagebreak()] else [#v(1cm)]
  == #section.heading
  #section.body
]

{
  "title": "Quarterly Berth Condition Report",
  "site": "Northern Marina, Oulu",
  "period": "Q3 2026",
  "sections": [
    {
      "heading": "Summary",
      "body": "Sixty-two berths were inspected during the period. Four require remedial work before the winter season and are listed in the findings below."
    },
    {
      "heading": "Findings",
      "body": "Berths B-14 and B-15 show fastener corrosion at the shoreward hinge. Berth C-02 has a damaged fender. Berth C-09 requires a replacement cleat."
    },
    {
      "heading": "Recommendations",
      "body": "Schedule the four remedial items before the first freeze. Re-inspect the B row after the works and update the asset labels accordingly."
    }
  ]
}

// A printable manual, typeset from the published documentation. The request carries the whole
// document in `data` and the logo as a `files` entry, so this template holds only presentation:
// a cover, a running header and footer, a table of contents, and one rule per content block.
//
// `data` is generated by scripts/manual_content.py from docs/ and zensical.toml, which is why the
// manual cannot drift from the site it is made of.

#let accent = rgb("#3f51b5")
#let shade = rgb("#f4f4f8")

// One inline span. These four kinds are all the converter emits.
#let span-content(span) = {
  if span.kind == "code" {
    raw(span.text)
  } else if span.kind == "strong" {
    strong(span.text)
  } else if span.kind == "link" {
    link(span.href, text(fill: accent, span.text))
  } else if span.kind == "ref" {
    // A link to another chapter of this manual rather than to the site it was made from.
    link(label(span.target), text(fill: accent, span.text))
  } else {
    span.text
  }
}

#let spans(items) = items.map(span-content).join()

#let cells(row) = row.map(cell => spans(cell))

// One content block. Headings keep the level they had on the page, so the page's own `#` becomes
// the chapter title the outline and the running header pick up.
#let content-block(item) = {
  if item.type == "heading" {
    heading(level: item.level, item.text)
  } else if item.type == "paragraph" {
    par(spans(item.spans))
  } else if item.type == "code" {
    block(
      width: 100%,
      fill: shade,
      inset: 6pt,
      radius: 3pt,
      breakable: true,
      text(size: 7.5pt, raw(item.text, lang: if item.language != "" { item.language })),
    )
  } else if item.type == "list" {
    list(..item.items.map(entry => spans(entry)))
  } else if item.type == "table" {
    block(
      breakable: true,
      text(size: 9pt, table(
        columns: item.header.len(),
        stroke: (x, y) => if y == 0 { (bottom: 0.6pt + accent) } else { (bottom: 0.2pt + luma(200)) },
        inset: 4.5pt,
        table.header(..cells(item.header).map(cell => strong(cell))),
        ..item.rows.map(row => cells(row)).flatten(),
      )),
    )
  }
}

// Two faces travel with the request, and only their Medium and Bold cuts, so every rule that
// selects one names one of those weights; asking for a weight that is absent would silently fall
// back to the body face.
#let display = "Space Grotesk" // headings
#let wordmark = "Inter Display" // the name and its tagline on the cover

#set text(size: 10pt)
#set par(justify: true, leading: 0.65em, spacing: 0.8em)
#show heading: set text(font: display)
#show heading.where(level: 1): set text(size: 17pt, weight: "bold", fill: accent)
#show heading.where(level: 2): set text(size: 12pt, weight: "medium")
#show heading.where(level: 3): set text(size: 10.5pt, weight: "medium")
#show heading: set block(above: 1.3em, below: 0.9em)
#show raw.where(block: false): set text(size: 9pt)

// Cover. Its own page rule keeps the header and footer off the first sheet.
#page(margin: 2.5cm, header: none, footer: none)[
  #v(3.5cm)
  // The mark ends 32 units above the bottom of its 256-unit viewBox, so bottom-aligning the boxes
  // would leave the name sitting below the mark it is set against. Lifting the text column by that
  // same proportion puts the two on one baseline whatever the logo is scaled to.
  #let logo-width = 62mm
  #let logo-clearance = logo-width * 32 / 256
  #grid(
    columns: (auto, 1fr),
    column-gutter: 12mm,
    align: (left + bottom, left + bottom),
    image(data.logo, width: logo-width),
    {
      // Measured by the glyph outlines rather than by the baseline: the tagline ends in descenders,
      // and aligning a baseline with the mark's hard edge leaves those hanging below it, which is
      // what the eye reads as "slightly too low".
      set text(font: wordmark, top-edge: "bounds", bottom-edge: "bounds")
      // Paragraph spacing would stack on top of the explicit gap below, so the lockup states its
      // own: the distance between the name and its tagline is a design decision, not a leftover.
      set par(spacing: 0pt)
      text(size: 40pt, weight: "bold", tracking: -1pt)[#data.title]
      v(3.5mm)
      text(size: 14pt, weight: "medium", fill: luma(95))[#data.subtitle]
      v(logo-clearance)
    },
  )
  #v(14mm)
  #block(width: 85%, text(size: 11pt)[#data.description])
  #v(1fr)
  #text(size: 9pt, fill: luma(110))[
    #link(data.site_url, data.site_url) \
    #link(data.repo_url, data.repo_url)
  ]
]

#set page(
  paper: "a4",
  margin: (top: 2.2cm, bottom: 2cm, x: 2cm),
  header: context {
    // The running header names the chapter the reader is in. Selection is by page number rather
    // than by `before(here())`: a header is laid out at the top of its page, so "before here"
    // would find the previous chapter on every page a chapter starts on.
    let current = here().page()
    let seen = query(heading.where(level: 1)).filter(item => item.location().page() <= current)
    if seen.len() > 0 {
      set text(size: 8pt, fill: luma(110))
      grid(
        columns: (1fr, auto),
        align: (left, right),
        emph(seen.last().body), data.title,
      )
      v(-6pt)
      line(length: 100%, stroke: 0.4pt + luma(200))
    }
  },
  footer: context {
    set text(size: 8pt, fill: luma(110))
    align(center, counter(page).display("1 / 1", both: true))
  },
)
#counter(page).update(1)

// The contents title is deliberately not a heading: chapters own level 1, and the running header
// above finds the current chapter by asking for exactly those.
#text(font: display, size: 17pt, weight: "bold", fill: accent)[Contents]
#v(6mm)
#outline(title: none, depth: 1)

#for chapter in data.chapters {
  pagebreak()
  // An empty anchor carrying the chapter's label, so a cross-reference in the text can jump here.
  [#metadata(chapter.id)#label(chapter.id)]
  if chapter.section != none {
    text(size: 8pt, fill: luma(130), tracking: 1pt, upper(chapter.section))
    v(-2mm)
  }
  chapter.blocks.map(content-block).join()
}