带答题卡的试卷

// ═══ Postext Cookbook · Nº 049 · Exam paper with an answer sheet ═════════════════
// https://postext.dev/en/cookbook/exam-paper
// Code: MIT · Text: Lincoln (PD); questions, Spanish translation (CC BY 4.0) · Art: in code
// Fonts: PT Serif, Inter Tight (SIL OFL 1.1) · Needs postext ≥ 1.4.1
import { buildDocument, renderPageToCanvas, clearMeasurementCache, registerResourceImage }
  from 'https://esm.sh/postext';

const LANG = 'en'; // @lang: the language of the sample document ('en' | 'es')
const RECIPE = 'exam-paper';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
const palette = { ink: '#1b1a1f', paper: '#ffffff', muted: '#6b6466', // heads, credits: 5.8:1
  crimson: '#9b1c31', // the one accent: cover, numbering, bubbles, marks (8.1:1 on white)
  blush: '#f3cdd4', tint: '#fbeff1', // type on the band, marks chips; the grid, the rubric box
  rule: '#b9aeb0' }; // answer lines and hairlines
// Hex and id: design slots and referenceColor read only the hex (gotcha: palette-skips-designs).
const col = (id) => ({ hex: palette[id], model: 'hex', paletteId: id });
// The engine's defaults are linked to 'main-color': point it at the accent.
const colorPalette = Object.entries({ ...palette, 'main-color': palette.crimson })
  .map(([id, hex]) => ({ id, name: id, value: { hex, model: 'hex' } }));
const [TEXT, LABEL, PAGE] = ['PT Serif', 'Inter Tight', { w: 215.9, h: 279.4 }]; // US Letter
const [TOP, BOTTOM, LEFT, MEASURE] = [22, 24, 24, 134]; // mm; 134 mm: about 75 characters
const RIGHT = PAGE.w - LEFT - MEASURE; // 57.9 mm: the examiner's margin, never mirrored
const [BODY, LEAD] = [11, 15]; // pt: text size and leading, the grid every line keeps to
const at = (x, y, size, edge = 'top-left') => ({ anchor: { to: 'page', edge },
  offset: { x: mm(x), y: mm(y) }, ...(size && { size }) });
const text = (id, content, family, size, weight, color, placement, extra) => ({ kind: 'text',
  id, content, fontFamily: family, fontSize: pt(size), fontWeight: weight, color: col(color),
  align: 'left', overflow: 'wrap', placement, ...extra });
const tag = { textTransform: 'uppercase', letterSpacing: pt(1.4) }; // 0.16–0.19 em
const small = { fontFamily: LABEL, fontSize: pt(7.5), lineHeight: pt(10), color: col('muted') };

// #region answer: ruled answer lines: a table whose rows are two body lines deep
// A table row is one line (the table's size × the body's leading ratio) plus cellPadding above
// and below: at the body size, (ROW − LEAD) / 2 of padding makes every row ROW deep, so the
// rules keep to the text's 15 pt grid, 10.6 mm apart: room for handwriting.
const ROW = 2 * LEAD; // pt
const lines = { id: 'lines', rules: 'horizontal', // a rule on the top and foot of every row
  borderColor: col('rule'), borderWidth: pt(0.5), bodyFontFamily: LABEL, bodyFontSize: pt(BODY),
  bodyColor: col('crimson'), cellPadding: pt((ROW - LEAD) / 2) };
// Every table in this paper is set 'here': where its ::resource directive stands in the text.
const table = (id, styleId, model) => ({ id, typeId: 'form', kind: 'table', createdAt: 0,
  updatedAt: 0, placement: { position: 'here' }, table: { styleId, model } });
// One table per answer, the part's number in its first margin cell.
const answerLines = (id, part, rows) => table(id, 'lines', { columnWidths: [1, 5], rows: Array
  .from({ length: rows }, (_, i) => [{ content: i ? '' : `**${part}**` }, { content: '' }]) });
// #endregion

// #region numbering: 11 → a) → i), the separators in the accent; options under a question
const [NUMBER, GAP] = [12.5, 6]; // pt: the question numbers' size; number to text
const orderedLists = { fontFamily: LABEL, color: col('ink'), // bold, by default
  separatorColor: col('crimson'), gap: pt(GAP), marginTop: pt(LEAD / 2), marginBottom: pt(0),
  itemSpacing: pt(5), // after every numbered item: to a question's options, or the next part
  levels: [{ level: 1, fontSize: pt(NUMBER) }, // 'arabic', '.' (gotcha: numbering-vocabularies)
    { level: 2, numberFormat: 'lower-alpha', separator: ')' },
    { level: 3, numberFormat: 'lower-roman', separator: ')' }] };
// Options: a nested item with no bullet, indented by the widest number ('10.') plus GAP.
const width = (s) => { const ctx = new OffscreenCanvas(1, 1).getContext('2d');
  ctx.font = `700 ${NUMBER}pt "${LABEL}"`; return ctx.measureText(s).width * 0.75; }; // pt
const unorderedLists = () => ({ gap: pt(0), marginTop: pt(0), marginBottom: pt(0),
  itemSpacing: pt(LEAD), // after the options: a line before the next question
  levels: [{ level: 2, bulletChar: '', indent: pt(width('10') + width('.') + GAP) }] });
// #endregion

// #region chips: bubbles that read as circles, and marks at the end of a part
// A chip is 0.8 em above the baseline and 0.25 em below, plus paddingY and the border on each
// side: 1.29 em and two borders. One capital is 0.63–0.72 em wide, so paddingX 0.3 em (and the
// same two borders) squares the box; a radius over half its smaller side is clamped to that half.
const chip = (id, look) => ({ id, fontFamily: LABEL, fontSize: em(0.8), bold: true,
  paddingY: em(0.12), ...look });
const bubble = (id, fill, ink, edge = 'crimson') => chip(id, { color: col(ink), paddingX: em(0.3),
  background: col(fill), borderColor: col(edge), borderWidth: pt(0.7), borderRadius: em(1) });
const chipStyles = [bubble('bubble', 'paper', 'crimson'), // first: a bare :chip[A] takes it
  bubble('filled', 'ink', 'paper', 'ink'), chip('marks', { color: col('crimson'),
    background: col('blush'), borderWidth: pt(0), paddingX: em(0.45), gap: em(0.5) })];
// #endregion

// #region forms: the candidate boxes and the bubble grid are named table styles too
// No table has a header row; the flag keeps the default grey fill off one added later.
const form = { bodyFontFamily: LABEL, borderRadius: mm(2), headerBackgroundEnabled: false };
const tableStyles = [lines,
  { ...form, id: 'candidate', rules: 'grid', borderColor: col('rule'), borderWidth: pt(0.75),
    bodyFontSize: pt(7.5), bodyColor: col('crimson'), cellPadding: mm(1.8) },
  // Tint fills leave hairline seams between cells on a canvas: grid rules in the tint hide them.
  { ...form, id: 'grid', rules: 'grid', borderColor: col('tint'), bodyBackgroundEnabled: true,
    bodyBackground: col('tint'), bodyFontSize: pt(11.5), cellPadding: mm(1.4) }];
const cell = (content, extra) => ({ content, align: 'center', verticalAlign: 'middle', ...extra });
// The MARK cell sets the row's depth: three lines, the blank one a U+2060 word joiner, since a
// cell line that is empty or holds only a no-break space is dropped (gotcha: cell-blank-line).
const candidate = table('candidate', 'candidate', { columnWidths: [4.2, 1.2, 2, 1.3], rows: [[
  ...t({ en: ['NAME', 'CLASS', 'CANDIDATE NUMBER'], es: ['NOMBRE Y APELLIDOS', 'GRUPO',
    'N.º DE EXAMEN'] }).map((l) => cell(`**${l}**`, { align: 'left', verticalAlign: 'top' })),
  cell(`**${t({ en: 'MARK', es: 'NOTA' })}**\n\u2060\n**/ ${t({ en: '25', es: '10' })}**`,
    { align: 'right', background: col('tint') })]] });
const GROUP = ['A', 'B', 'C', 'D'].map((l) => cell(`:chip[${l}]`)), num = (n) => cell(`**${n}**`);
const grid = { ...table('grid', 'grid', { columnWidths: [0.7, 1, 1, 1, 1, 1.4, 0.7, 1, 1, 1, 1],
  rows: [1, 2, 3, 4, 5].map((n) => [num(n), ...GROUP, cell(''), num(n + 5), ...GROUP]) }),
  caption: t({ en: '**Section A answer grid**', es: '**Parte A: plantilla de respuestas**' }) };
// The grid's title is its caption: a heading would stand a body line off any 'here' table.
const captionStyle = { fontFamily: LABEL, fontSize: pt(9.4), color: col('crimson'),
  position: 'above', gap: mm(1.6) }; // the rubric's size
// #endregion

// #region cover: a band with the outlined year, filled in from the heading's attributes
const BAND = 116; // mm: the crimson band, bled off the top and both sides
const YEAR = { cap: 62, cut: 12, pad: 2 }; // mm: the digits' cap height; the band cuts 12 off
// span 'page': an opener page, and the band paints above the column (a design in it is clipped).
const cover = { id: 'cover', span: 'page', margins: { right: mm(LEFT) }, // forms full width
  advancedDesign: { enabled: true, slot: { elements: [ // the date line sets the height
    { kind: 'box', id: 'band', style: { backgroundColor: col('crimson') },
      placement: at(0, 0, { width: mm(PAGE.w), height: mm(BAND) }) },
    // Design text has no outline, so the year is an image, cut off by the band's foot.
    { kind: 'image', id: 'year', resourceId: 'year', placement: at(0, BAND - YEAR.cap
      + YEAR.cut - YEAR.pad, { width: mm(PAGE.w), height: mm(YEAR.cap - YEAR.cut + YEAR.pad) }) },
    text('session', '{attr.session}', LABEL, 8.5, 600, 'blush', at(LEFT, 14), tag),
    // 0.9 mm to the left: the H's side bearing at 64 pt (84 of 2048 units), so its stem aligns.
    text('title', '{titleText}', LABEL, 64, 800, 'paper', at(LEFT - 0.9, 19), { lineHeight: 1 }),
    text('paper', '{attr.paper}', LABEL, 15, 700, 'paper', at(LEFT, 44)),
    text('topic', '{attr.topic}', TEXT, 15, 400, 'blush', at(LEFT, 52), { italic: true }),
    text('date', '{attr.date}', LABEL, 9.5, 700, 'ink', at(LEFT, BAND + 6))] } } };
// #endregion

// #region furniture: margin, folio and 'Turn over' on body pages; a notice on the cover
const [MARGIN, FOOT] = [LEFT + MEASURE + 7, -13]; // mm: the margin rule, 7 off the text; the foot
const body = { pages: 'body', ...tag }; // body pages only: never the cover
const header = { elements: [
  text('running', '{title} · {chapterTitle}', LABEL, 7.5, 600, 'muted', at(LEFT, 12), body),
  { kind: 'rule', id: 'margin', direction: 'vertical', pages: 'body', color: col('rule'),
    thickness: pt(0.75), placement: at(MARGIN, TOP, { height: mm(PAGE.h - TOP - BOTTOM) }) },
  text('note', t({ en: 'Do not write in this margin', es: 'No escribas en este margen' }), LABEL,
    7.5, 600, 'muted', at(MARGIN + 3, TOP, { width: mm(28) }), { ...body, lineHeight: 1.3 })] };
const footer = { elements: [
  text('notice', t({ en: 'Do not turn over until you are told to do so',
    es: 'No des la vuelta a la hoja hasta que se te indique' }), LABEL, 8.5, 700, 'crimson',
  at(0, FOOT, { width: mm(PAGE.w) }, 'bottom-left'), { pages: 'opener', align: 'center', ...tag }),
  text('folio', '{pageNumber}', LABEL, 9, 700, 'ink', at(LEFT, FOOT, { width: mm(MEASURE) },
    'bottom-left'), { ...body, align: 'center' }), // centred under the text
  // Rectos only: a verso faces the page that follows it.
  text('turn', t({ en: 'Turn over ›', es: 'Pasa la página ›' }), LABEL, 9, 700, 'ink',
    at(-RIGHT, FOOT, null, 'bottom-right'), { ...body, parity: 'odd', align: 'right' })] };
// #endregion

const section = { enabled: true, slot: { elements: [ // Section A, Section B: in the column
  { kind: 'rule', id: 'top', color: col('crimson'), thickness: pt(2),
    placement: { anchor: { to: 'container', edge: 'top-left' }, size: { width: 'fill' } } },
  text('kicker', '{attr.section} · {attr.marks}', LABEL, 8.5, 700, 'crimson', { anchor: {
    to: 'container', edge: 'top-left' }, offset: { y: mm(3) } }, tag),
  text('title', '{titleText}', LABEL, 20, 800, 'ink', { anchor: { to: '#kicker',
    edge: 'below' }, offset: { y: mm(1.2) }, size: { width: 'fill' } }, { lineHeight: 1.05 })] } };

const config = () => ({ // a factory, never a shared object (gotcha: config-cache-identity)
  locale: t({ en: 'en-us', es: 'es' }), // exact codes only (gotcha: hyphenation-locales)
  resourceTypes: [{ id: 'form', name: 'Form', shortLabel: '', captionPrefix: '',
    numberingTemplate: '{n}', resetOn: 'never', counterFormat: 'decimal' }], // no label
  colorPalette, chipStyles, tableStyles, captionStyle, orderedLists, header, footer,
  headingStyles: [cover], unorderedLists: unorderedLists(), // measured now that the fonts are in
  page: { width: mm(PAGE.w), height: mm(PAGE.h), dpi: 150, margins: { top: mm(TOP),
    bottom: mm(BOTTOM), left: mm(LEFT), right: mm(RIGHT) } }, layout: { layoutType: 'single' },
  bodyText: { fontFamily: TEXT, fontSize: pt(BODY), lineHeight: pt(LEAD), color: col('ink'),
    boldColor: col('ink'), italicColor: col('ink'), referenceColor: col('ink'),
    textAlign: 'left', firstLineIndent: pt(0), paragraphSpacing: true },
  // No page break: a :::pagebreak opens each section, so its page stays a body page with a
  // folio. A heading that breaks the page makes an opener, which pages: 'body' leaves bare.
  headings: { fontFamily: LABEL, levels: [{ level: 1, breakBefore: { enabled: false },
    marginTop: pt(0), marginBottom: pt(0), advancedDesign: section }] },
  calloutStyles: [{ id: 'rubric', background: col('tint'), borderRadius: mm(2), columnGap: mm(8),
    padding: { top: mm(4), right: mm(5), bottom: mm(4), left: mm(5) }, marginTop: pt(0),
    marginBottom: pt(0), lists: { bulletChar: '–', color: col('crimson'), gap: mm(2),
      itemSpacing: pt(3) }, body: { fontFamily: LABEL, fontSize: pt(9.4), lineHeight: pt(13),
      boldColor: col('crimson'), paragraphSpacing: false } },
  { id: 'source', backgroundEnabled: false, marginTop: pt(LEAD), stripe: { enabled: true,
    side: 'left', width: pt(3), color: col('crimson') }, padding: { top: mm(1), right: mm(0),
    bottom: mm(1), left: mm(6) }, titleStyle: { fontFamily: LABEL, fontSize: pt(8.5),
      fontWeight: 700, color: col('crimson'), gap: mm(2), ...tag }, body: { fontSize: pt(10.5),
      lineHeight: pt(LEAD), textAlign: 'justify', paragraphSpacing: false,
      firstLineIndent: mm(4) } }],
  paragraphStyles: [{ id: 'signature', textAlign: 'right' }, { id: 'credit', ...small },
    { id: 'end', ...small, boldColor: col('crimson'), textAlign: 'center', spaceBetween: pt(8) }],
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
Markdown样例 · 100行 · content.en.md
title: "History Paper 2"
subtitle: "The American Civil War, 1863"
---

# History {style="cover" session="Mock examinations · Spring 2026" paper="Paper 2 · Sources and interpretations" topic="The American Civil War, 1863" date="Thursday 14 May 2026 · Morning · Time allowed: 1 hour 15 minutes"}

::resource{id="candidate"}

:::callout{type="rubric"}
:::columns{count=2 breaks="6"}
**Instructions**

- Use black ink. Use a pencil for Section A.
- Answer every question.
- Section A: shade one bubble for each question, like this: :chip[C]{style="filled"}. Rub out any mark you change.
- Section B: write on the lines on page 4.

**Information**

- The number of marks is shown at the end of each part, like this: :chip[4 marks]{style="marks"}
- Section A: 10 marks. Section B: 15 marks.
- Spend about 45 minutes on Section B.
:::
:::

::resource{id="grid"}

:::pagebreak

# Multiple choice {section="Section A" marks="10 marks"}

Shade one bubble for each question in the grid on page 1:

1. The Emancipation Proclamation took effect on 1 January 1863. Where did it declare enslaved people free?
  - :chip[A] every state :chip[B] border states :chip[C] rebel states :chip[D] western states
2. Who commanded the Union army at the Battle of Gettysburg?
  - :chip[A] U. S. Grant :chip[B] G. G. Meade :chip[C] G. B. McClellan :chip[D] W. T. Sherman
3. Which Confederate stronghold surrendered on 4 July 1863?
  - :chip[A] New Orleans :chip[B] Vicksburg :chip[C] Memphis :chip[D] Baton Rouge
4. How many years are “four score and seven”?
  - :chip[A] 47 :chip[B] 67 :chip[C] 87 :chip[D] 107
5. Who gave the two-hour main oration at the dedication of the cemetery at Gettysburg?
  - :chip[A] E. Everett :chip[B] F. Douglass :chip[C] W. H. Seward :chip[D] J. Hay
6. Under the Enrollment Act of March 1863, what could a drafted man pay to be excused from service?
  - :chip[A] \$100 :chip[B] \$300 :chip[C] \$500 :chip[D] \$1,000
7. Which regiment of Black soldiers led the assault on Fort Wagner, South Carolina, in July 1863?
  - :chip[A] 20th Maine :chip[B] 9th Ohio :chip[C] 2nd Iowa :chip[D] 54th Massachusetts
8. Which state joined the Union on 20 June 1863?
  - :chip[A] Nevada :chip[B] West Virginia :chip[C] Kansas :chip[D] Nebraska
9. At which battle in May 1863 was General Thomas “Stonewall” Jackson mortally wounded?
  - :chip[A] Chancellorsville :chip[B] Antietam :chip[C] Fredericksburg :chip[D] Shiloh
10. Which city saw four days of riots against the draft in July 1863?
  - :chip[A] Boston :chip[B] Philadelphia :chip[C] New York :chip[D] Chicago

:::pagebreak

# Source-based questions {section="Section B" marks="15 marks"}

:::callout{type="source" title="Source A"}
Four score and seven years ago our fathers brought forth, on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.

Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this.

But, in a larger sense, we can not dedicate—we can not consecrate—we can not hallow—this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us—that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion—that we here highly resolve that these dead shall not have died in vain—that this nation, under God, shall have a new birth of freedom—and that government of the people, by the people, for the people, shall not perish from the earth.

:::paragraphs{style="signature"}
*Abraham Lincoln. November 19, 1863.*
:::
:::

:::paragraphs{style="credit"}
Lincoln’s address at the dedication of the Soldiers’ National Cemetery, Gettysburg, 19 November 1863; the text of the Bliss copy, the last of five in his hand and the only one he signed.
:::

11. Study Source A, then answer every part on the lines on page 4.
  1. Lincoln counts back “four score and seven years” in his first line.
    1. Which year is he counting back to? :chip[1 mark]{style="marks"}
    2. Explain why Lincoln dated the nation’s birth from that year, and not from 1787, when the Constitution was written. :chip[2 marks]{style="marks"}
  2. Lincoln says the war is “testing whether that nation … can long endure”. Describe two ways in which the Union was stronger in November 1863 than in January. :chip[4 marks]{style="marks"}
  3. “The address honours the dead but says little about the future of the nation.” How far do you agree? Explain your answer with Source A and your own knowledge. :chip[8 marks]{style="marks"}

:::pagebreak

Write your answers to Question 11 on these lines.

::resource{id="lines-ai"}

::resource{id="lines-aii"}

::resource{id="lines-b"}

::resource{id="lines-c"}

:::space

:::paragraphs{style="end"}
**END OF QUESTIONS**

Source A: the Gettysburg Address, Bliss copy, in the public domain. Questions written for this paper, CC BY 4.0. Set in PT Serif and Inter Tight, SIL Open Font License.
:::
`; // content.<lang>.md, inlined by the Cookbook

// #region art: the outlined year
// The digits are Inter Tight 800 outlines (SIL OFL), 102.4 units to the em, cap height 74.5,
// on a baseline at 0: an SVG drawn as an image cannot use web fonts (gotcha: svg-no-webfonts).
const YEAR_OUTLINE = 'M38.2-74.5V0H20.2V-57.7H19.8L3.1-47.5V-63.1L21.5-74.5ZM75.8 1Q67.1 1 60.3-1.8'
  + 'Q53.6-4.5 49.7-9.3Q45.8-14.1 45.8-20.1Q45.8-24.8 48-28.6Q50.2-32.5 54-35'
  + 'Q57.8-37.6 62.5-38.4V-38.9Q56.4-40.1 52.4-44.7Q48.5-49.2 48.5-55.4Q48.5-61.2 52-65.7'
  + 'Q55.6-70.2 61.8-72.9Q68-75.5 75.8-75.5Q83.7-75.5 89.9-72.9Q96.1-70.2 99.7-65.7'
  + 'Q103.2-61.2 103.2-55.4Q103.2-49.2 99.2-44.6Q95.2-40.1 89.2-38.9V-38.4'
  + 'Q93.8-37.6 97.6-35Q101.4-32.5 103.7-28.6Q105.9-24.8 105.9-20.1Q105.9-14.1 102-9.3'
  + 'Q98.2-4.5 91.4-1.8Q84.6 1 75.8 1ZM75.8-11.7Q79.2-11.7 81.7-13Q84.2-14.2 85.6-16.5'
  + 'Q87-18.8 87-21.7Q87-24.5 85.6-26.8Q84.1-29 81.6-30.3Q79.1-31.6 75.8-31.6'
  + 'Q72.6-31.6 70.1-30.3Q67.6-29 66.1-26.8Q64.7-24.6 64.7-21.7Q64.7-18.8 66.1-16.5'
  + 'Q67.5-14.3 70-13Q72.6-11.7 75.8-11.7ZM75.8-44.3Q78.7-44.3 80.9-45.5'
  + 'Q83.1-46.6 84.3-48.7Q85.6-50.8 85.6-53.4Q85.6-56 84.3-58Q83.1-60 80.9-61.1'
  + 'Q78.7-62.2 75.8-62.2Q73-62.2 70.8-61.1Q68.6-60 67.3-58Q66.1-56 66.1-53.4'
  + 'Q66.1-50.8 67.3-48.7Q68.6-46.7 70.8-45.5Q73-44.3 75.8-44.3ZM143.7 1Q137.6 1 132-1'
  + 'Q126.4-3 122.1-7.3Q117.7-11.7 115.2-18.7Q112.7-25.8 112.7-36Q112.7-45.2 114.9-52.5'
  + 'Q117.1-59.8 121.2-65Q125.4-70.1 131.1-72.8Q136.9-75.5 144-75.5Q151.9-75.5 157.8-72.5'
  + 'Q163.8-69.4 167.4-64.3Q171-59.2 171.7-53H154Q153.2-56.5 150.5-58.3Q147.8-60.2 144-60.2'
  + 'Q137.2-60.2 133.8-54.2Q130.5-48.4 130.5-38.4H130.9Q132.5-41.8 135.3-44.2'
  + 'Q138.2-46.6 141.9-47.8Q145.7-49.1 149.8-49.1Q156.5-49.1 161.6-46Q166.7-43 169.6-37.6'
  + 'Q172.5-32.2 172.5-25.3Q172.5-17.5 168.9-11.6Q165.2-5.7 158.7-2.3Q152.2 1 143.7 1Z'
  + 'M143.6-12.9Q146.9-12.9 149.5-14.4Q152.1-16 153.6-18.7Q155.1-21.4 155.1-24.7'
  + 'Q155.1-28.1 153.6-30.8Q152.1-33.5 149.5-35Q147-36.6 143.6-36.6Q140.4-36.6 137.7-35'
  + 'Q135.1-33.4 133.6-30.7Q132.1-28.1 132.1-24.7Q132.1-21.4 133.6-18.7Q135.1-16 137.7-14.4'
  + 'Q140.3-12.9 143.6-12.9ZM208.3 1Q199.8 1 193.2-1.9Q186.6-4.8 182.8-10'
  + 'Q179.1-15.2 179-21.9H197.1Q197.2-19.5 198.6-17.6Q200.1-15.7 202.7-14.7'
  + 'Q205.2-13.7 208.4-13.7Q211.6-13.7 214-14.8Q216.5-15.9 217.8-17.9Q219.2-19.9 219.2-22.5'
  + 'Q219.2-25.2 217.7-27.2Q216.2-29.2 213.4-30.4Q210.7-31.5 206.9-31.5H199.6V-44.3H206.9'
  + 'Q210.2-44.3 212.7-45.4Q215.2-46.5 216.6-48.5Q218-50.5 218-53Q218-55.6 216.8-57.4'
  + 'Q215.6-59.3 213.5-60.4Q211.3-61.5 208.4-61.5Q205.4-61.5 203-60.4Q200.6-59.3 199.2-57.4'
  + 'Q197.8-55.5 197.7-53H180.5Q180.5-59.6 184.2-64.7Q187.8-69.8 194.1-72.6'
  + 'Q200.4-75.5 208.5-75.5Q216.5-75.5 222.5-72.7Q228.6-69.9 232-65.1Q235.4-60.2 235.4-54.2'
  + 'Q235.4-48 231.3-43.9Q227.2-39.8 220.7-38.8V-38.2Q229.3-37.2 233.7-32.6'
  + 'Q238.1-28.1 238.1-21.2Q238.1-14.7 234.3-9.7Q230.5-4.7 223.7-1.8Q217 1 208.3 1Z';
function year() { // 10 units to the millimetre
  const [w, h] = [PAGE.w * 10, (YEAR.cap - YEAR.cut + YEAR.pad) * 10];
  const s = (YEAR.cap * 10) / 74.5; // scale: cap height to YEAR.cap
  const x = LEFT * 10 - 3.1 * s; // the 1's flag starts 3.1 units in: line it up with the text
  return `<svg xmlns="http://www.w3.org/2000/svg" width="${w}" height="${h}" viewBox="0 0 ${w} `
    + `${h}"><path transform="translate(${x.toFixed(1)} ${(YEAR.cap + YEAR.pad) * 10}) `
    + `scale(${s.toFixed(4)})" d="${YEAR_OUTLINE}" fill="none" stroke="${palette.paper}" `
    + `stroke-width="${(8.5 / s).toFixed(3)}" stroke-linejoin="round"/></svg>`; // 0.85 mm
}
// typeId 'form' too: the drawing is placed by the cover's design, never by ::resource, and a
// type with no captionPrefix spares it a figure number.
const picture = { id: 'year', typeId: 'form', kind: 'svg', altText: '1863', createdAt: 0,
  updatedAt: 0, svg: { fileId: 'year.svg', width: PAGE.w * 10,
    height: (YEAR.cap - YEAR.cut + YEAR.pad) * 10 } }; // in the drawing's own units
// #endregion

const resources = [picture, candidate, grid, answerLines('lines-ai', '11 a) i)', 1),
  answerLines('lines-aii', '11 a) ii)', 2), answerLines('lines-b', '11 b)', 4),
  answerLines('lines-c', '11 c)', 8)];

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
const FONTS = { 'PT Serif': ['400', '400i', '700', '700i'], // (gotcha: fonts-first)
  'Inter Tight': ['400', '600', '700', '800'] };

// ─── 4 · Build & show ───────────────────────────────────────────────────────
await Promise.all([loadFonts(FONTS, markdown), loadSvg('year.svg', year())]);
const doc = await buildWithFonts(() => buildDocument({ markdown, resources }, config()), markdown);
showPages(doc, { title: t({ en: 'History Paper 2', es: 'Historia, prueba 2' }) });

工具包 · core, fonts, viewer, images：每道食谱都相同 · 270行
// ─── Kit ── helpers shared by every Cookbook recipe · postext.dev/cookbook ─────

// ─── Kit · core v1 ── the same in every recipe · postext.dev/cookbook ─────────
function mm(value) { return { value, unit: 'mm' }; }
function pt(value) { return { value, unit: 'pt' }; }
function em(value) { return { value, unit: 'em' }; }
/** The sample language's string: t({ en: 'Figure', es: 'Figura' }). */
function t(strings) { return strings[LANG] ?? Object.values(strings)[0]; }
/** A file in this recipe's assets folder, served from the Postext repo by jsDelivr. */
function asset(file) { return `https://cdn.jsdelivr.net/gh/drnachio/postext@main/cookbook/${RECIPE}/assets/${file}`; }

// ─── Kit · fonts v1 ── the same in every recipe · postext.dev/cookbook ────────
// Postext measures text with the faces the browser has loaded, and caches the
// widths, so every face must be ready before the first build. Faces come from
// Fontsource: the same static files the PDF embeds, so screen and PDF agree.

/** faces = { 'Family Name': ['400', '400i', '700'] }. `text` is the sample:
 *  letters beyond Latin-1 (č, ł, ő…) also load the latin-ext files. With
 *  `optional`, a face Fontsource does not ship is skipped instead of failing.
 *  Resolves to the number of faces added. */
async function loadFonts(faces, text = '', { optional = false } = {}) {
  kitStatus('Loading fonts…');
  const ranges = {
    latin: 'U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,'
      + 'U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD',
    'latin-ext': 'U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,'
      + 'U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF',
  };
  const subsets = /[Ā-˿Ḁ-ỿ]/.test(text) ? ['latin', 'latin-ext'] : ['latin'];
  const jobs = [];
  let added = 0;
  for (const [family, specs] of Object.entries(faces)) {
    const id = fontsourceId(family);
    const meta = optional ? await fontsourceMeta(family) : null;
    for (const spec of new Set(specs)) {
      const weight = parseInt(spec, 10);
      const style = spec.endsWith('i') ? 'italic' : 'normal';
      if (hasFace(family, weight, style)) continue;
      if (optional && !(meta?.weights.includes(weight) && meta.styles.includes(style))) continue;
      for (const subset of subsets) {
        const url = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${weight}-${style}.woff2`;
        const face = new FontFace(family, `url(${url}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: ranges[subset] });
        jobs.push(face.load().then((ready) => { document.fonts.add(ready); added++; }, () => {
          if (subset === 'latin' && !optional) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
        }));
      }
    }
  }
  await Promise.all(jobs).catch((error) => { kitFail(error); throw error; });
  return added;
}

/** Runs `build` (a buildDocument or buildBundle call) and checks the faces
 *  the pages use. A regular face missing from FONTS is loaded with a warning;
 *  bold and italic variants are loaded when the family ships them. Then the
 *  measurement caches are cleared and the build runs again. */
async function buildWithFonts(build, text = '') {
  const tried = new Set();
  for (let round = 0; round < 3; round++) {
    kitStatus('Laying out…');
    await new Promise(requestAnimationFrame);          // let the status paint first
    const result = await Promise.resolve().then(build).catch((error) => { kitFail(error); throw error; });
    const wanted = { base: {}, variants: {} };
    for (const { font, base } of [result].flat().flatMap(fontStringsOf)) {
      const { family, weight, style } = parseFont(font);
      const key = `${family}|${weight}|${style}`;
      if (tried.has(key) || hasFace(family, weight, style)) continue;
      tried.add(key);
      (wanted[base ? 'base' : 'variants'][family] ??= []).push(`${weight}${style === 'italic' ? 'i' : ''}`);
    }
    if (Object.keys(wanted.base).length) {
      console.warn(`[cookbook] FONTS does not list ${JSON.stringify(wanted.base)}: loading them.`);
    }
    const added = await loadFonts(wanted.base, text) + await loadFonts(wanted.variants, text, { optional: true });
    if (added === 0) return result;
    clearMeasurementCache();
  }
  throw new Error('The fonts did not settle after three builds.');
}

/** Every font string of the layout. `base` marks a block's own face; its
 *  bold, italic and bold-italic variants are listed whether or not used. */
function fontStringsOf(doc) {
  const found = new Map();
  const walk = (node) => {
    if (!node || typeof node !== 'object') return;
    if (Array.isArray(node)) { node.forEach(walk); return; }
    for (const [key, value] of Object.entries(node)) {
      if (typeof value === 'string' && /fontString$/i.test(key)) {
        found.set(value, found.get(value) || key === 'fontString');
      } else if (value && typeof value === 'object') walk(value);
    }
  };
  walk(doc.pages);
  walk(doc.blocks);
  return [...found].map(([font, base]) => ({ font, base }));
}

/** '700 37.5px Open Sans' / 'italic 400 13px "Source Serif 4"' → { family, weight, style }.
 *  A string with no weight ('95.8px Young Serif', from a design text) is 400. */
function parseFont(font) {
  const m = /^(?:(italic|oblique)\s+)?(?:small-caps\s+)?(?:(\d+|bold|normal)\s+)?[\d.]+px\s+(.+)$/.exec(font.trim());
  if (!m) throw new Error(`Unexpected font string: ${font}`);
  const weight = m[2] === 'bold' ? 700 : !m[2] || m[2] === 'normal' ? 400 : Number(m[2]);
  return { family: m[3].replace(/^["']|["']$/g, ''), weight, style: m[1] ? 'italic' : 'normal' };
}

/** True when a loaded FontFace covers exactly this family, weight and style
 *  (document.fonts.check() is also true for families nobody declared). */
function hasFace(family, weight, style) {
  for (const face of document.fonts) {
    if (face.status !== 'loaded' || face.style !== style) continue;
    if (face.family.replace(/^["']|["']$/g, '') !== family) continue;
    const [low, high = low] = face.weight.split(' ').map(Number);
    if (weight >= low && weight <= high) return true;
  }
  return false;
}

/** Fontsource's id for a family: 'Source Serif 4' → 'source-serif-4'. */
function fontsourceId(family) { return family.toLowerCase().replace(/\s+/g, '-'); }

/** The weights and styles a family ships ({ weights: [400, 700], styles: ['normal', 'italic'] }), or null. */
function fontsourceMeta(family) {
  fontsourceMeta.cache ??= new Map();
  const id = fontsourceId(family);
  if (!fontsourceMeta.cache.has(id)) {
    fontsourceMeta.cache.set(id, fetch(`https://api.fontsource.org/v1/fonts/${id}`)
      .then((res) => (res.ok ? res.json() : null), () => null));
  }
  return fontsourceMeta.cache.get(id);
}

// ─── Kit · viewer v1 ── the same in every recipe · postext.dev/cookbook ───────
/** Shows the pages as facing spreads on a dark desk: the first page is a
 *  recto on its own, then verso | recto pairs, as in a bound book. Pages
 *  are painted when they scroll near the screen. */
function showPages(docs, { title, width = 460 } = {}) {
  const root = viewer(title);
  const pages = [docs].flat().flatMap((doc) =>
    doc.pages.map((page) => ({ doc, page, n: (doc.pageIndexOffset ?? 0) + page.index })));
  const spreads = [];
  let verso = null;
  for (const p of pages) {
    if (p.n % 2 === 1) { if (verso) spreads.push([verso, null]); verso = p; }
    else { spreads.push([verso, p]); verso = null; }
  }
  if (verso) spreads.push([verso, null]);
  const density = Math.min(window.devicePixelRatio || 1, 2);
  showPages.painter?.disconnect();
  const painter = new IntersectionObserver((entries) => {
    for (const { isIntersecting, target } of entries) {
      if (!isIntersecting) continue;
      painter.unobserve(target);
      const { doc, page } = target.postext;
      renderPageToCanvas(page, doc, target, { scale: (width * density) / page.width });
    }
  }, { rootMargin: '800px' });
  showPages.painter = painter;
  root.replaceChildren(...spreads.map((pair) => {
    const spread = document.createElement('div');
    spread.className = 'pt-spread';
    for (const p of pair) {
      const figure = document.createElement('figure');
      if (p) {
        const label = p.page.pageLabel || String(p.n + 1);
        const canvas = document.createElement('canvas');
        canvas.postext = p;
        canvas.style.aspectRatio = `${p.page.width} / ${p.page.height}`;
        canvas.setAttribute('role', 'img');
        canvas.setAttribute('aria-label', `Page ${label}`);
        const folio = document.createElement('figcaption');
        folio.textContent = label;
        figure.append(canvas, folio);
        painter.observe(canvas);
      } else figure.className = 'pt-blank';
      spread.append(figure);
    }
    return spread;
  }));
  kitStatus(`${pages.length} ${pages.length === 1 ? 'page' : 'pages'}`);
  document.documentElement.dataset.postext = 'ready';
  return pages.length;
}

/** The desk, the bar and the error reporting, created once. */
function viewer(title) {
  if (!document.getElementById('pt-kit')) {
    document.head.insertAdjacentHTML('beforeend', `<style id="pt-kit">
      :root { color-scheme: dark; }
      body { margin: 0; background: #0e1014; color: #b9bcc4; font: 13px/1.45 system-ui, sans-serif; }
      #pt-bar { position: sticky; top: 0; z-index: 1; display: flex; flex-wrap: wrap; align-items: center;
        gap: 6px 16px; padding: 10px 16px; background: rgb(14 16 20 / .92); backdrop-filter: blur(6px);
        border-bottom: 1px solid #23262d; }
      #pt-bar strong { color: #f4f1ea; font-weight: 600; }
      #pt-actions { display: flex; gap: 12px; margin-left: auto; }
      #pt-actions a, #pt-actions button { color: #d8a21a; font: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
      #pages { display: grid; justify-items: center; gap: 48px; padding: 32px 16px 72px; }
      .pt-spread { display: flex; }
      .pt-spread figure { margin: 0; width: min(460px, 44vw); }
      .pt-spread canvas { display: block; width: 100%; background: #fff;
        box-shadow: 0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
      .pt-spread figure:first-child canvas { box-shadow: inset -14px 0 14px -14px rgb(0 0 0 / .18), 0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
      .pt-spread figcaption { margin-top: 10px; text-align: center; font: 600 10px/1 system-ui, sans-serif;
        letter-spacing: .18em; text-transform: uppercase; color: #6c7079; }
      .pt-blank { visibility: hidden; }
      @media (max-width: 760px) {
        .pt-spread { flex-direction: column; gap: 32px; }
        .pt-spread figure { width: min(460px, 92vw); }
        .pt-blank { display: none; }
      }
    </style>`);
    document.body.insertAdjacentHTML('afterbegin',
      '<header id="pt-bar"><strong id="pt-title"></strong><span id="pt-status" role="status"></span><span id="pt-actions"></span></header>');
    document.getElementById('pt-title').textContent = document.title || 'Postext';
    addEventListener('error', (event) => kitFail(event.error ?? event.message));
    addEventListener('unhandledrejection', (event) => kitFail(event.reason));
  }
  if (title) document.getElementById('pt-title').textContent = title;
  return document.getElementById('pages')
    ?? document.body.appendChild(Object.assign(document.createElement('main'), { id: 'pages' }));
}

function kitStatus(text) {
  viewer();
  document.getElementById('pt-status').textContent = text;
}

function kitFail(error) {
  document.documentElement.dataset.postext = 'error';
  kitStatus(`Error: ${error?.message ?? error}`);
}

// ─── Kit · images v1 ── recipes with pictures · postext.dev/cookbook ──────────
/** Registers a photo or PNG for the canvas and keeps its bytes for the PDF.
 *  fetch → ImageBitmap never taints the canvas (a plain cross-origin <img> would). */
async function loadImage(fileId, url) {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`Image not found (${res.status}): ${url}`);
  const bytes = new Uint8Array(await res.arrayBuffer());
  registerResourceImage(fileId, await createImageBitmap(new Blob([bytes])));
  (loadImage.bytes ??= new Map()).set(fileId, bytes);
}

/** Registers SVG markup (drawn in code, or fetched) as a vector image. */
async function loadSvg(fileId, svg) {
  const img = new Image();
  img.src = `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`;
  await img.decode();
  registerResourceImage(fileId, img);
  (loadImage.bytes ??= new Map()).set(fileId, new TextEncoder().encode(svg));
}

/** renderToPdf({ resourceBytes: imageBytes }) */
function imageBytes(fileId) { return loadImage.bytes?.get(fileId); }

/** renderToHtml({ resourceImageUrl: imageUrl }) */
function imageUrl(fileId) {
  const bytes = imageBytes(fileId);
  if (!bytes) return undefined;
  imageUrl.urls ??= new Map();
  if (!imageUrl.urls.has(fileId)) {
    const type = /\.svg$/i.test(fileId) ? 'image/svg+xml' : /\.png$/i.test(fileId) ? 'image/png' : 'image/jpeg';
    imageUrl.urls.set(fileId, URL.createObjectURL(new Blob([bytes], { type })));
  }
  return imageUrl.urls.get(fileId);
}

// ─── /Kit ───────────────────────────────────────────────────────────────────────