# Um caderno de exercícios chinês, do aluno e do professor

> Um 练习册 de língua e matemática: seções 一、二、, parênteses （　）, 田字格 e contas armadas, composto duas vezes a partir de um texto, para o aluno e o professor.

- Versão HTML: https://postext.dev/pt/cookbook/chinese-exercise-book
- Receita Nº 171 · Livros didáticos · Nível 2 (Intermediário) · Saídas: Canvas, PDF
- Gêneros: Cadernos de exercícios, Livros didáticos
- Requer postext ≥ 1.59.0, postext-pdf ≥ 1.59.0 · testada com 1.59.0, postext-pdf 1.59.0 em 2026-10-24
- Páginas: [1](https://postext.dev/cookbook/chinese-exercise-book/zh/p01.webp?v=0914fd07), [2](https://postext.dev/cookbook/chinese-exercise-book/zh/p02.webp?v=0914fd07), [3](https://postext.dev/cookbook/chinese-exercise-book/zh/p03.webp?v=0914fd07), [4](https://postext.dev/cookbook/chinese-exercise-book/zh/p04.webp?v=0914fd07), [1](https://postext.dev/cookbook/chinese-exercise-book/zh/p05.webp?v=0914fd07), [2](https://postext.dev/cookbook/chinese-exercise-book/zh/p06.webp?v=0914fd07), [3](https://postext.dev/cookbook/chinese-exercise-book/zh/p07.webp?v=0914fd07), [4](https://postext.dev/cookbook/chinese-exercise-book/zh/p08.webp?v=0914fd07)
- Abrir no Sandbox: https://postext.dev/pt/sandbox#recipe=chinese-exercise-book&lang=zh (.postext: https://postext.dev/cookbook/chinese-exercise-book/zh/chinese-exercise-book.postext)
- Última atualização: 2026-10-24
- Outros idiomas: [en](https://postext.dev/en/cookbook/chinese-exercise-book.md), [es](https://postext.dev/es/cookbook/chinese-exercise-book.md), [ca](https://postext.dev/ca/cookbook/chinese-exercise-book.md), [de](https://postext.dev/de/cookbook/chinese-exercise-book.md), [fr](https://postext.dev/fr/cookbook/chinese-exercise-book.md), [it](https://postext.dev/it/cookbook/chinese-exercise-book.md), [zh](https://postext.dev/zh/cookbook/chinese-exercise-book.md), [ja](https://postext.dev/ja/cookbook/chinese-exercise-book.md), [ar](https://postext.dev/ar/cookbook/chinese-exercise-book.md)

## Em poucas palavras

Um caderno de exercícios de escola primária chinesa: duas unidades de língua e de matemática. O mesmo texto gera a cópia do aluno, com lacunas e gabarito no fim, e a do professor, com cada resposta escrita em vermelho no lugar dela.

## O que você vai compor

Duas unidades de um 练习册 do segundo ano no formato 16开: uma de língua, 春天来了, e uma de matemática sobre adição e subtração até 100. Cada uma abre com uma faixa em aquarela, uma aba com a matéria e uma linha para turma, nome e nota, e segue pelas seções que um caderno chinês imprime: 看拼音写词语, leituras para circular, 选择题 com um （　） depois do enunciado e A. B. C. D. em linha, 判断题 com um parêntese no fim da linha, lacunas, 连线 entre classificadores e coisas, uma frase para escrever em 田字格, 口算 em quatro colunas, 竖式 com um quadrinho por algarismo e um problema. Os pontos de cada questão ficam no enunciado, onde o aluno os lê. O mesmo Markdown é composto duas vezes: o livro do aluno, com o 参考答案 no fim de cada unidade, e o do professor, com cada resposta escrita em Kai vermelha no seu lugar.

**Esta receita responde a:**

- Como componho questões chinesas com um （　） depois do enunciado e as opções A. B. C. D. em linha?
- Como faço o livro do professor, com as respostas impressas no lugar, a partir do livro do aluno?
- Como dou a uma pergunta aberta pauta Seyès, quadriculado ou quadros 田字格 para escrever?
- Como componho a divisão longa do jeito que as escolas de cada país a escrevem?

## A resposta curta

```js
// script.js, linhas 36–65
// The exercise style is the form; the Markdown holds every word, the points included. The
// same text builds both editions: `edition: 'teacher'` writes each answer into its blank,
// bracket and square in red Kai, rings the right options and draws the matching lines.
const lianxi = {
  id: 'lianxi',
  number: { format: 'simp-chinese-informal', suffix: '、', fontFamily: HEI, color: col('green') },
  instruction: { fontFamily: HEI, bold: false }, // 黑体, not bold: the points stay quiet
  // 选择题: A. B. C. D. in a row, a （　） after the stem for the letter.
  options: { labels: 'alpha-upper', suffix: '.', layout: 'row', bracket: true },
  trueFalse: { look: 'bracket' }, // 判断题: （　） at the end of the line, √ or ×
  blank: { look: 'line', color: col('ink') },
  area: { kind: 'tianzige', color: col('rule') }, // 写话 on 田字格
  match: { color: col('green') },
  grid: { fontFamily: SONG, rule: col('rule') },
  answers: { color: col('red'), fontFamily: KAI },
  solutions: { box: 'daan' },
  marginTop: em(1.2), marginBottom: em(0.6),
};
const exerciseStyles = [
  lianxi,
  // 看拼音写词语: a box under each syllable, as wide as its word.
  { id: 'pinyin', extends: 'lianxi', blank: { look: 'box', width: 'answer', color: col('rule') } },
  // 在（　）里填: the bracket is in the text, the blank inside it draws nothing.
  { id: 'kuohao', extends: 'lianxi', blank: { look: 'none', width: 'answer' } },
];
let edition = 'student'; // the second build below prints the teacher's book
// The pupil's book: 参考答案 where a :::solutions line stands, at the end of each unit.
// The teacher's book: every answer on the page, so no key at the end.
const exercises = () => ({ edition,
  solutions: { placement: edition === 'teacher' ? 'none' : 'directive' } });
```

## Ingredientes

**Ensina**

- [Estilos de exercício](https://postext.dev/pt/docs/exercises.md#estilos-de-exercício): exerciseStyles: como se imprime uma família de exercícios: o número (círculo, quadrado, rótulo), o enunciado, as letras das alternativas, as lacunas, as caixas de V/F, os pontos para ligar, o banco de palavras, as áreas de escrita, as grades, os ícones de atividade e a dificuldade.
- [Livro do professor](https://postext.dev/pt/docs/exercises.md#edição-do-professor): exercises.edition: 'teacher' imprime cada resposta no seu lugar numa segunda cor e circula as alternativas certas: o livro do professor a partir do texto do aluno.
- [Escolha e verdadeiro ou falso](https://postext.dev/pt/docs/exercises.md#múltipla-escolha-e-verdadeiro-ou-falso): Múltipla escolha a partir de uma lista de tarefas (- [x] certa, - [ ] errada), com a) b) c), A. B. C., ア イ ウ ou أ ب ج e uma caixa, um círculo ou parênteses para responder; afirmações de verdadeiro ou falso com as letras do idioma.

**Também usa**

- [Exercícios](https://postext.dev/pt/docs/exercises.md#exercícios)
- [Lacunas e bancos de palavras](https://postext.dev/pt/docs/exercises.md#lacunas-e-banco-de-palavras)
- [Ligar e classificar](https://postext.dev/pt/docs/exercises.md#ligar-colunas-e-classificar)
- [Perguntas abertas e áreas de escrita](https://postext.dev/pt/docs/exercises.md#perguntas-abertas-e-áreas-de-escrita)
- [Contas armadas](https://postext.dev/pt/docs/exercises.md#contas-armadas)
- [Gabarito](https://postext.dev/pt/docs/exercises.md#soluções)
- [Numeração chinesa](https://postext.dev/pt/docs/configuration-page-layout.md#numeração)
- [Fontes chinesas, japonesas e coreanas](https://postext.dev/pt/docs/configuration-pdf-output.md#fontes-chinesas-japonesas-e-coreanas)
- [Grade de caracteres](https://postext.dev/pt/docs/configuration-east-asian.md#grade-de-caracteres)
- [Pontos de ênfase e linhas de nome e de título](https://postext.dev/pt/docs/document-format-inline.md#marcas-chinesas-rubi-e-warichu)
- [Chips no texto](https://postext.dev/pt/docs/configuration-styles.md#estilos-de-chip)
- [Três ou mais colunas](https://postext.dev/pt/docs/configuration-page-layout.md#tipos-de-layout)
- [Aberturas desenhadas](https://postext.dev/pt/docs/configuration-headings.md#largura-e-design-avançado)
- [Atributos de título](https://postext.dev/pt/docs/document-format.md#atributos-de-título)
- [Imagens nos designs de página](https://postext.dev/pt/docs/configuration-headers-footers.md#elementos-de-imagem)
- [Paleta de cores semântica](https://postext.dev/pt/docs/configuration-fonts-colors-viewers.md#paleta-de-cores)
- [Exportação para PDF](https://postext.dev/pt/docs/configuration-pdf-output.md#geração-de-pdf)
- [Colunas num boxe ou no texto](https://postext.dev/pt/docs/document-format-directives.md#columns)
- [Boxes que se dividem ou ficam inteiros](https://postext.dev/pt/docs/configuration-callouts.md#o-contêiner-callout)
- [Quebra de linha em chinês](https://postext.dev/pt/docs/configuration-east-asian.md#tipografia-do-leste-asiático)
- [Equilíbrio de colunas](https://postext.dev/pt/docs/configuration-page-flow.md#equilíbrio-de-colunas)
- [Estilos de parágrafo](https://postext.dev/pt/docs/configuration-styles.md#estilos-de-parágrafo)
- [Fontes incorporadas ao PDF](https://postext.dev/pt/docs/configuration-pdf-output.md#por-que-um-provedor-de-fontes)
- [Figuras e tabelas como recursos](https://postext.dev/pt/docs/document-format-resources.md#recursos)

**A configuração em resumo**

- [`bodyText`](https://postext.dev/pt/docs/configuration-text.md#texto-do-corpo), [`calloutStyles`](https://postext.dev/pt/docs/configuration-callouts.md#estilos-de-boxe), [`chipStyles`](https://postext.dev/pt/docs/configuration-styles.md#estilos-de-chip), [`cjk`](https://postext.dev/pt/docs/configuration-east-asian.md#tipografia-do-leste-asiático), [`colorPalette`](https://postext.dev/pt/docs/configuration-fonts-colors-viewers.md#paleta-de-cores), `exerciseStyles`, `exercises`, [`footer`](https://postext.dev/pt/docs/configuration-headers-footers.md#cabeçalhos-e-rodapés), [`header`](https://postext.dev/pt/docs/configuration-headers-footers.md#cabeçalhos-e-rodapés), [`headings`](https://postext.dev/pt/docs/configuration-headings.md#títulos), [`layout`](https://postext.dev/pt/docs/configuration-page-layout.md#diagramação), [`locale`](https://postext.dev/pt/docs/configuration-language.md#hifenização), [`orderedLists`](https://postext.dev/pt/docs/configuration-lists-math.md#listas-numeradas), [`page`](https://postext.dev/pt/docs/configuration-page-layout.md#página), [`paragraphStyles`](https://postext.dev/pt/docs/configuration-styles.md#estilos-de-parágrafo)

**API**

- [`buildDocument`](https://postext.dev/pt/docs/configuration-programmatic-usage.md#compilar-um-documento), [`decompressWoff2`](https://postext.dev/pt/docs/configuration-pdf-output.md#provedor-de-fontes-no-navegador-fontsource--woff2), [`registerResourceImage`](https://postext.dev/pt/docs/architecture.md#superfície-da-api), [`renderPageToCanvas`](https://postext.dev/pt/docs/configuration-programmatic-usage.md#renderizar-uma-página-como-bitmap), [`renderToPdf`](https://postext.dev/pt/docs/configuration-pdf-output.md#geração-de-pdf), [`withLoadedFonts`](https://postext.dev/pt/docs/configuration-programmatic-usage.md#carregar-as-fontes-antes-da-diagramação)

**Tipos**

- Noto Serif SC (OFL-1.1), Noto Sans SC (OFL-1.1), LXGW WenKai TC (OFL-1.1)

## Preparo

### 1 · Um estilo para todas as seções

O código é [a resposta curta](https://postext.dev/pt/cookbook/chinese-exercise-book.md#a-resposta-curta) logo acima. As seções são contadas com numerais chineses seguidos de um 、 de largura inteira, então nenhum espaço vem depois do número; o enunciado é composto na Hei, sem negrito, para que os pontos entre parênteses sejam lidos como parte dele. `options.bracket` escreve o （　） depois de cada enunciado, e no livro do professor a letra certa entra nele. Os dois estilos pequenos estendem o principal: `pinyin` desenha cada lacuna como um quadrinho da largura da palavra, `kuohao` não desenha nada, porque o parêntese de 在（　）里填 está no texto.

### 2 · O livro do aluno e o do professor a partir de um texto

```js
// script.js, linhas 334–338
const build = () => withLoadedFonts(() => buildDocument({ markdown, resources }, config()),
  { ...kitFonts(FONTS), text: markdown });
const pupil = await build();
edition = 'teacher';
const docs = [pupil, await build()];
```

A configuração é uma função, então cada composição recebe o próprio objeto e o pacote do Sandbox guarda o do aluno. `edition: 'teacher'` escreve as respostas na cor e na fonte de `answers`: as palavras nos quadrinhos, as letras nos parênteses, √ e × nos 判断题, os algarismos nas casas do 竖式, a frase modelo com um caractere por quadrado. O livro do aluno guarda o gabarito para a linha `:::solutions` no fim de cada unidade; o do professor não precisa dele.

### 3 · Uma abertura de unidade com a sua pintura

```js
// script.js, linhas 69–87
const BAND = 184 / 2.4; // mm: the painting's height at the page's width
const opener = { enabled: true, minHeight: mm(BAND - 22 + 23), slot: { elements: [
  { kind: 'image', id: 'picture', resourceId: '{attr.pic}', decorative: true, reserve: false,
    placement: { anchor: { to: 'page', edge: 'top-left' },
      size: { width: mm(184), height: mm(BAND) } } },
  { kind: 'text', id: 'subject', content: '{attr.kicker}', fontFamily: HEI, fontSize: pt(11),
    fontWeight: 700, color: col('paper'), letterSpacing: pt(2), align: 'center',
    box: { backgroundColor: col('green'), borderRadius: mm(1.5),
      padding: { top: mm(0.8), bottom: mm(0.8), left: mm(2.4), right: mm(2) } },
    placement: { anchor: { to: 'container', edge: 'top-left' },
      offset: { x: mm(0), y: mm(BAND - 22 + 6) } } },
  { kind: 'text', id: 'title', content: '{titleText}', fontFamily: HEI, fontSize: pt(24),
    fontWeight: 700, color: col('ink'), align: 'left',
    placement: { anchor: { to: '#subject', edge: 'right-of' },
      offset: { x: mm(4), y: mm(-2.6) } } },
  { kind: 'rule', id: 'rule', direction: 'horizontal', thickness: pt(1.2), color: col('green'),
    placement: { anchor: { to: 'container', edge: 'top-left' },
      offset: { x: mm(0), y: mm(BAND - 22 + 19) }, size: { width: 'fill' } } },
] } };
```

A pintura fica ancorada à página, então chega à borda superior tanto numa página ímpar quanto numa par; a aba e o título são posicionados a partir do topo da mancha de texto, abaixo do pé da pintura. As duas unidades compartilham o design e só mudam nos atributos do título, `kicker` e `pic`.

### 4 · Fólios no pé

```js
// script.js, linhas 91–101
const foot = (id, content, parity, edge, x, extra = {}) => ({ kind: 'text', id, content,
  parity, fontFamily: HEI, fontSize: pt(8), color: col('muted'),
  placement: { anchor: { to: 'page', edge }, offset: { x: mm(x), y: mm(-10) } }, ...extra });
const footer = { elements: [
  foot('folio-v', '{pageNumber}', 'even', 'bottom-left', 16,
    { fontWeight: 700, color: col('green') }),
  foot('series', '{title}', 'even', 'bottom-left', 24),
  foot('unit', '{chapterTitle}', 'odd', 'bottom-right', -24, { align: 'right' }),
  foot('folio-r', '{pageNumber}', 'odd', 'bottom-right', -16,
    { fontWeight: 700, color: col('green'), align: 'right' }),
] };
```

Os cadernos chineses põem o fólio no pé. O título da série vem do front matter do Markdown (`{title}`), e o da unidade, do seu título (`{chapterTitle}`).

## A receita completa

Um único arquivo, composto a partir da pasta da receita com o texto de exemplo e o kit comum das Receitas já incluídos; ele monta a própria página. Para executá-lo, coloque-o em um `<script type="module">` de uma página vazia ou cole-o no painel JS de um pen novo do CodePen (como módulo). Ele importa o postext do esm.sh, então não há nada para instalar nem compilar.

- Pasta da receita: https://github.com/drnachio/postext/tree/main/cookbook/chinese-exercise-book

### script.js

```js
// ═══ Postext Cookbook · Nº 171 · A Chinese exercise book, pupil's and teacher's ═══
// https://postext.dev/en/cookbook/chinese-exercise-book
// Code: MIT · Text: original (CC BY 4.0) · Pictures: generated with diffusion models
// Fonts: Noto Serif SC, Noto Sans SC, LXGW WenKai TC (SIL OFL 1.1) · Needs postext ≥ 1.59.0
import {
  buildDocument, withLoadedFonts, renderPageToCanvas, registerResourceImage,
} from 'https://esm.sh/postext';
import { renderToPdf, decompressWoff2 } from 'https://esm.sh/postext-pdf';

const LANG = 'zh'; // @lang: the language of the frame; the exercise book is Chinese in all
const RECIPE = 'chinese-exercise-book';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
// #region palette: a green exercise book, and the red of the teacher's pen
const palette = {
  ink: '#1f2523', // text: a green-tinted near-black
  green: '#2c7350', // the one accent: section numbers, the subject tab, the squares
  red: '#d0352c', // the teacher's answers
  tint: '#e6f2ea', // the subject tab's ground, the answers box
  rule: '#8fb9a2', // 田字格, the matching dots' lines
  muted: '#68736d', // folios, the series line
  paper: '#ffffff',
};
const col = (id) => ({ hex: palette[id], model: 'hex', paletteId: id });
const colorPalette = [
  ...Object.entries(palette).map(([id, hex]) => ({ id, name: id, value: { hex, model: 'hex' } })),
  { id: 'main-color', name: 'accent (defaults)', value: { hex: palette.green, model: 'hex' } },
];
// #endregion
// 宋 for the text, 黑 for the instructions and labels, 楷 for what the teacher writes.
const [SONG, HEI, KAI] = ['Noto Serif SC', 'Noto Sans SC', 'LXGW WenKai TC'];
const CHARS = 40; // characters per line: 40 × 10.5 pt = 148 mm
const SIZE = 10.5; // pt: 五号, the size of a school book's text

// #region answer: sections 一、二、 that print the pupil's book or the teacher's
// The exercise style is the form; the Markdown holds every word, the points included. The
// same text builds both editions: `edition: 'teacher'` writes each answer into its blank,
// bracket and square in red Kai, rings the right options and draws the matching lines.
const lianxi = {
  id: 'lianxi',
  number: { format: 'simp-chinese-informal', suffix: '、', fontFamily: HEI, color: col('green') },
  instruction: { fontFamily: HEI, bold: false }, // 黑体, not bold: the points stay quiet
  // 选择题: A. B. C. D. in a row, a （　） after the stem for the letter.
  options: { labels: 'alpha-upper', suffix: '.', layout: 'row', bracket: true },
  trueFalse: { look: 'bracket' }, // 判断题: （　） at the end of the line, √ or ×
  blank: { look: 'line', color: col('ink') },
  area: { kind: 'tianzige', color: col('rule') }, // 写话 on 田字格
  match: { color: col('green') },
  grid: { fontFamily: SONG, rule: col('rule') },
  answers: { color: col('red'), fontFamily: KAI },
  solutions: { box: 'daan' },
  marginTop: em(1.2), marginBottom: em(0.6),
};
const exerciseStyles = [
  lianxi,
  // 看拼音写词语: a box under each syllable, as wide as its word.
  { id: 'pinyin', extends: 'lianxi', blank: { look: 'box', width: 'answer', color: col('rule') } },
  // 在（　）里填: the bracket is in the text, the blank inside it draws nothing.
  { id: 'kuohao', extends: 'lianxi', blank: { look: 'none', width: 'answer' } },
];
let edition = 'student'; // the second build below prints the teacher's book
// The pupil's book: 参考答案 where a :::solutions line stands, at the end of each unit.
// The teacher's book: every answer on the page, so no key at the end.
const exercises = () => ({ edition,
  solutions: { placement: edition === 'teacher' ? 'none' : 'directive' } });
// #endregion

// #region opener: the unit's painting to the bleed, the subject tab and the title
const BAND = 184 / 2.4; // mm: the painting's height at the page's width
const opener = { enabled: true, minHeight: mm(BAND - 22 + 23), slot: { elements: [
  { kind: 'image', id: 'picture', resourceId: '{attr.pic}', decorative: true, reserve: false,
    placement: { anchor: { to: 'page', edge: 'top-left' },
      size: { width: mm(184), height: mm(BAND) } } },
  { kind: 'text', id: 'subject', content: '{attr.kicker}', fontFamily: HEI, fontSize: pt(11),
    fontWeight: 700, color: col('paper'), letterSpacing: pt(2), align: 'center',
    box: { backgroundColor: col('green'), borderRadius: mm(1.5),
      padding: { top: mm(0.8), bottom: mm(0.8), left: mm(2.4), right: mm(2) } },
    placement: { anchor: { to: 'container', edge: 'top-left' },
      offset: { x: mm(0), y: mm(BAND - 22 + 6) } } },
  { kind: 'text', id: 'title', content: '{titleText}', fontFamily: HEI, fontSize: pt(24),
    fontWeight: 700, color: col('ink'), align: 'left',
    placement: { anchor: { to: '#subject', edge: 'right-of' },
      offset: { x: mm(4), y: mm(-2.6) } } },
  { kind: 'rule', id: 'rule', direction: 'horizontal', thickness: pt(1.2), color: col('green'),
    placement: { anchor: { to: 'container', edge: 'top-left' },
      offset: { x: mm(0), y: mm(BAND - 22 + 19) }, size: { width: 'fill' } } },
] } };
// #endregion

// #region furniture: folios at the foot, the series line on the verso, the unit on the recto
const foot = (id, content, parity, edge, x, extra = {}) => ({ kind: 'text', id, content,
  parity, fontFamily: HEI, fontSize: pt(8), color: col('muted'),
  placement: { anchor: { to: 'page', edge }, offset: { x: mm(x), y: mm(-10) } }, ...extra });
const footer = { elements: [
  foot('folio-v', '{pageNumber}', 'even', 'bottom-left', 16,
    { fontWeight: 700, color: col('green') }),
  foot('series', '{title}', 'even', 'bottom-left', 24),
  foot('unit', '{chapterTitle}', 'odd', 'bottom-right', -24, { align: 'right' }),
  foot('folio-r', '{pageNumber}', 'odd', 'bottom-right', -16,
    { fontWeight: 700, color: col('green'), align: 'right' }),
] };
// #endregion

const config = () => ({
  locale: 'zh-Hans', // written out: Kaiming punctuation, no hyphenation
  colorPalette,
  page: { sizePreset: 'custom', width: mm(184), height: mm(260), dpi: 150, // 16开
    margins: { top: mm(22), bottom: mm(20), left: mm(18), right: mm(16), mirror: true } },
  layout: { layoutType: 'single' },
  cjk: { grid: { enabled: true, charsPerLine: CHARS, linesPerPage: 29 } },
  bodyText: { fontFamily: SONG, fontSize: pt(SIZE), lineHeight: pt(21), color: col('ink'),
    boldColor: col('ink'), italicColor: col('ink'), referenceColor: col('ink'),
    textAlign: 'justify', firstLineIndent: pt(0), avoidWidows: true, avoidOrphans: true },
  headings: { fontFamily: HEI, color: col('ink'), fontWeight: 700, balancing: { enabled: false },
    levels: [{ level: 1, fontSize: pt(24), breakBefore: { parity: 'any' },
      advancedDesign: opener }] },
  orderedLists: { numberFormat: 'arabic', color: col('ink'), fontWeight: 400 },
  paragraphStyles: [
    // 班级、姓名、得分 at the head of each unit
    { id: 'xinxi', fontFamily: HEI, fontSize: pt(9.5), textAlign: 'right', firstLineIndent: pt(0),
      color: col('muted'), marginBottom: mm(2) },
    { id: 'colophon', fontFamily: HEI, fontSize: pt(7.5), lineHeight: pt(11), color: col('muted'),
      textAlign: 'left', firstLineIndent: pt(0), marginTop: mm(6) },
  ],
  chipStyles: [{ id: 'xian', backgroundEnabled: false, underline: 'solid', borderWidth: pt(0.6),
    borderColor: col('muted'), minWidth: mm(24), paddingX: pt(0), paddingY: pt(0) }],
  calloutStyles: [{ id: 'daan', background: col('tint'), borderRadius: mm(2),
    padding: { top: mm(3), right: mm(4), bottom: mm(3.5), left: mm(4) },
    titleStyle: { fontFamily: HEI, fontSize: pt(11), fontWeight: 700, color: col('green') },
    body: { fontSize: pt(9.5), lineHeight: pt(17), color: col('ink'), firstLineIndent: pt(0) },
    marginTop: mm(6), marginBottom: mm(2), keepTogether: false }],
  exerciseStyles,
  exercises: exercises(),
  header: { elements: [] },
  footer,
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
title: "二年级下册　语文数学同步练习"
---

# 第一单元　春天来了 {kicker="语文" pic="spring"}

:::paragraphs{style="xinxi"}
班级:chip[　]{style="xian"}　姓名:chip[　]{style="xian"}　得分:chip[　]{style="xian"}
:::

:::exercise{style=pinyin}
看拼音，写词语。（每词1分，共8分）

:::columns{count=4}
chūn tiān

[[春天]]

liǔ shù

[[柳树]]

xiǎo cǎo

[[小草]]

yàn zi

[[燕子]]

wēn nuǎn

[[温暖]]

huā duǒ

[[花朵]]

zhǒng zi

[[种子]]

tián yě

[[田野]]
:::
:::

:::exercise
用“○”圈出加点字的正确读音。（每题1分，共3分）

:::columns{count=3}
*种*子 [[(zhǒng) | zhòng]]

春*风* [[(fēng) | fēn]]

*发*芽 [[(fā) | fà]]
:::
:::

:::exercise
选择题。把正确答案的序号填在括号里。（每题2分，共4分）

1. “春风吹绿了柳树”中，“吹绿”的意思是
   - [ ] 把柳树涂绿了
   - [x] 使柳树发芽变绿
   - [ ] 把柳树吹弯了
2. 下面哪个词语和“温暖”的意思相近？
   - [ ] 寒冷
   - [ ] 凉快
   - [x] 暖和
   - [ ] 炎热
:::

:::exercise{type=truefalse}
判断对错。对的画“√”，错的画“×”。（每题1分，共3分）

- [x] 燕子是春天从南方飞回来的。
- [ ] “桃花”和“桃子”说的是同一样东西。
- [x] 可以说“一朵花”，也可以说“一朵云”。
:::

:::exercise
按课文内容填空。（每空1分，共4分）

春天来了，小草从地下[[探出]]头来，柳树长出了[[嫩绿]]的新芽。小燕子从[[南方]]飞回来了，田野里到处都是[[花香]]。
:::

:::exercise
连一连，给事物找到合适的量词。（共4分）

- 一朵 -> 桃花
- 一只 -> 燕子
- 一棵 -> 柳树
- 一片 -> 田野
:::

:::exercise{type=open area=tianzige lines=3}
用上“春风”“柳树”“燕子”中的两个词，写一两句话。（4分）

:::solution
春风吹来，柳树发出了嫩绿的新芽。
:::
:::

:::solutions

# 第一单元　100以内的加减法 {kicker="数学" pic="market"}

:::paragraphs{style="xinxi"}
班级:chip[　]{style="xian"}　姓名:chip[　]{style="xian"}　得分:chip[　]{style="xian"}
:::

:::exercise
直接写得数。（每题1分，共8分）

:::columns{count=4}
25 + 37 = [[62]]

90 − 46 = [[44]]

8 × 7 = [[56]]

63 ÷ 9 = [[7]]

48 + 26 = [[74]]

71 − 38 = [[33]]

6 × 9 = [[54]]

42 ÷ 6 = [[7]]
:::
:::

:::exercise{style=kuohao}
在（　）里填上“>”“<”或“=”。（每题1分，共4分）

:::columns{count=4}
45 + 8（[[>]]）50

36 − 9（[[=]]）27

7 × 8（[[<]]）60

81 ÷ 9（[[>]]）8
:::
:::

:::exercise{type=arithmetic}
用竖式计算。（每题3分，共12分）

- 345 + 278
- 902 - 456
- 124 × 3
- 864 ÷ 4
:::

:::exercise{type=open area=lines lines=3}
解决问题。妈妈买了45个橘子，分给邻居18个，还剩多少个？（4分）

:::solution
45 − 18 = 27（个）　答：还剩27个。
:::
:::

:::solutions

:::paragraphs{style="colophon"}
字体：Noto Serif SC、Noto Sans SC、LXGW WenKai TC（SIL OFL）　插图：扩散模型生成　题目为本书原创（CC BY 4.0）
:::
`; // content.zh.md: one text for both editions

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
const FONTS = {
  'Noto Serif SC': ['400', '700'], // 宋: the text, the pinyin
  'Noto Sans SC': ['400', '700'], // 黑: instructions, numbers, titles
  'LXGW WenKai TC': ['400'], // 楷: the teacher's answers
};

// ─── 4 · Build & show ───────────────────────────────────────────────────────
// Each face loads the files of the characters it sets (gotcha: cjk-fonts-slices); the Kai
// sets the answers, so it loads them all.
const answers = [...markdown.matchAll(/\[\[([^\]]+)\]\]/g)].map((m) => m[1]).join('')
  + markdown.split(':::solution').slice(1).join('') + '√×ABCD0123456789';
await loadFonts(FONTS, markdown);
await loadCjkFonts({ [SONG]: FONTS[SONG], [HEI]: FONTS[HEI] }, markdown);
await loadCjkFonts({ [KAI]: FONTS[KAI] }, answers);
const resources = [];
for (const [id, file] of [['spring', 'spring-1600.jpg'], ['market', 'market-1600.jpg']]) {
  await loadImage(file, asset(file));
  resources.push({ id, typeId: 'figure', kind: 'bitmap', createdAt: 0, updatedAt: 0,
    bitmap: { fileId: file, format: 'jpeg', width: 1600, height: 667 } });
}
// #region editions: one text, two books: the pupil's, then the teacher's
const build = () => withLoadedFonts(() => buildDocument({ markdown, resources }, config()),
  { ...kitFonts(FONTS), text: markdown });
const pupil = await build();
edition = 'teacher';
const docs = [pupil, await build()];
// #endregion
showPages(docs, { title: t({ zh: '练习册：学生用书与教师用书', en: 'A Chinese exercise book',
  es: 'Un cuaderno de ejercicios chino' }) });
offerPdf(() => renderToPdf(docs, { fontProvider: cjkPdfProvider, resourceBytes: imageBytes }),
  `${RECIPE}.pdf`);

// ─── 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 v3 ── the same in every recipe · postext.dev/cookbook
// Postext loads the faces a config asks for before layout and asks the kit
// for Fontsource's files, the ones the PDF embeds too.

/** buildDocumentWithFonts' options: the resolver, and FONTS' faces loaded
 *  with the config's. FONTS = { 'Family Name': ['400', '400i', '700'] }. */
function kitFonts(FONTS = {}) {
  const faces = Object.entries(FONTS).flatMap(([family, specs]) => specs.map((spec) =>
    ({ family, weight: parseInt(spec, 10), style: spec.endsWith('i') ? 'italic' : 'normal' })));
  return { resolve: fontsourceResolver, faces };
}

/** A face's files with their ranges: latin, then latin-ext and greek when
 *  `text` needs them (kitSubsetsFor). Null for a face Fontsource lacks. */
async function fontsourceResolver(family, weight, style, { text = '' } = {}) {
  const id = fontsourceId(family);
  const meta = await fontsourceMeta(family);
  if (meta && !(await fontsourceWeights(family, style)).includes(weight)) return null;
  kitStatus('Loading fonts…');
  const at = await fontsourceAt(id);
  return ['latin', ...kitSubsetsFor(text, meta)].map((subset) => ({
    source: `${at}files/${id}-${subset}-${weight}-${style}.woff2`,
    unicodeRange: kitRanges()[subset],
  }));
}

/** Each file's unicode-range (a function: the kit runs after the pen's code). */
function kitRanges() {
  return {
    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',
    greek: 'U+0370-03FF',
  };
}

/** For the cjk, arabic and comics blocks: loads `faces` (as FONTS) for the
 *  sample `text`; `optional` skips a face Fontsource lacks. Files are added in
 *  the order asked, the last winning a shared character. Resolves to the count. */
async function loadFonts(faces, text = '', { optional = false } = {}) {
  kitStatus('Loading fonts…');
  const ranges = kitRanges();
  const jobs = [];
  for (const [family, specs] of Object.entries(faces)) {
    const id = fontsourceId(family);
    const todo = [...new Set(specs)].map((spec) => [parseInt(spec, 10), spec.endsWith('i') ? 'italic' : 'normal'])
      .filter(([weight, style]) => !hasFace(family, weight, style)); // before any await
    const at = fontsourceAt(id);
    const meta = optional || /[^\0-ÿ]/u.test(text) ? await fontsourceMeta(family) : null;
    const subsets = ['latin', ...kitSubsetsFor(text, meta)];
    for (const [weight, style] of todo) {
      if (optional && !(meta && (await fontsourceWeights(family, style)).includes(weight))) continue;
      for (const subset of subsets) {
        const url = `${await at}files/${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().catch(() => {
          if (subset === 'latin' && !optional) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
        }));
      }
    }
  }
  const ready = await Promise.all(jobs).catch((error) => { kitFail(error); throw error; });
  return ready.filter((face) => face && document.fonts.add(face)).length;
}

/** A loaded FontFace covers this face (fonts.check() says yes to any family). */
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;
}

/** The files beyond latin `text` needs that `meta`'s family ships. */
function kitSubsetsFor(text, meta) {
  return [[/[Ā-˿ᴀ-ᶿḀ-ỿ†ℓⱠ-Ɀ꜠-ꟿ]/u, 'latin-ext'], [/[Ͱ-Ͽ]/u, 'greek']]
    .filter(([re, x]) => re.test(text) && meta?.subsets?.includes(x)).map(([, x]) => x);
}

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

/** A package's folder at the one version @5 names now (#766). */
function fontsourceAt(id, u = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@`) {
  return (fontsourceAt.c ??= {})[id] ??= fetch(u + '5/package.json').then((r) => r.json())
    .then((p) => p.version || 5, () => 5).then((v) => `${u}${v}/`);
}

/** The family's Fontsource metadata (weights, styles, subsets), or null. */
function fontsourceMeta(family, id = fontsourceId(family)) {
  return (fontsourceMeta.c ??= {})[id] ??= fetch(`https://api.fontsource.org/v1/fonts/${id}`)
    .then((res) => (res.ok ? res.json() : null), () => null);
}

/** The weights the package ships in `style`: the API pairs none (no Libre
 *  Caslon 700 italic file), so italics are read from latin-italic.css. */
function fontsourceWeights(family, style, id = fontsourceId(family)) {
  return (fontsourceWeights.c ??= {})[id + style] ??= fontsourceMeta(family).then(async (m) => {
    if (!m?.styles.includes(style)) return m ? [] : [400, 700];
    const css = style === 'italic' ? await fetch(`${await fontsourceAt(id)}latin-italic.css`).then((r) => (r.ok ? r.text() : ''), () => '') : '';
    const w = [...css.matchAll(/weight: (\d+)/g)].map((x) => +x[1]);
    return w.length ? w : m.weights;
  });
}

// ─── Kit · viewer v2 ── the same in every recipe · postext.dev/cookbook
/** The pages as spreads on a dark desk, page 1 alone, then verso | recto,
 *  each painted when it scrolls near. Other options go to renderPageToCanvas. */
function showPages(docs, { title, width = 460, ...render } = {}) {
  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, { ...render, 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 · pdf v3 ── the same in every recipe that exports a PDF
/** The Fontsource files the screen used, as TrueType, with their range and
 *  place: the nearest weight the family ships in that style, upright with no italic;
 *  latin, then what its letters need (kitSubsetsFor). */
async function fontsourceProvider(family, weight, style, request) {
  const id = fontsourceId(family);
  const meta = await fontsourceMeta(family);
  const s = style === 'italic' && meta && !meta.styles.includes('italic') ? 'normal' : style;
  const shipped = meta ? await fontsourceWeights(family, s) : [];
  const weights = shipped.length ? shipped : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const text = String.fromCodePoint(...(request?.codePoints ?? []));
  const files = await Promise.all(['latin', ...kitSubsetsFor(text, meta)].map(async (subset, order) => {
    const res = await fetch(`${await fontsourceAt(id)}files/${id}-${subset}-${w}-${s}.woff2`);
    if (!res.ok) throw new Error(`Fontsource has no ${family} ${w} ${s} ${subset}`);
    return Object.assign(await decompressWoff2(new Uint8Array(await res.arrayBuffer())),
      { unicodeRange: kitRanges()[subset], order });
  }));
  return files.length === 1 ? files[0] : files;
}

/** A "Build the PDF" button; then "Open the PDF" (a new tab: CodePen's frame
 *  shows no PDFs) and a download link. */
function offerPdf(makePdf, filename) {
  viewer();
  const button = Object.assign(document.createElement('button'), { type: 'button', textContent: 'Build the PDF' });
  button.dataset.postextPdf = filename;
  button.addEventListener('click', async () => {
    button.disabled = true;
    button.textContent = 'Building the PDF…';
    try {
      const bytes = await makePdf();
      const url = URL.createObjectURL(new Blob([bytes], { type: 'application/pdf' }));
      const size = `${Math.max(1, Math.round(bytes.length / 1024))} KB`;
      button.replaceWith(
        Object.assign(document.createElement('a'), { href: url, target: '_blank', rel: 'noopener', textContent: 'Open the PDF ↗' }),
        Object.assign(document.createElement('a'), { href: url, download: filename, textContent: `Download ${filename} · ${size}` }));
    } catch (error) {
      button.disabled = false;
      button.textContent = 'Build the PDF';
      kitFail(error);
    }
  });
  document.getElementById('pt-actions').append(button);
}

// ─── Kit · images v3 ── 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 as a vector image, its fonts inside (inlineSvgFonts, ≥ 1.25).
 *  `options` go to registerResourceImage: { singleInk: true } tints it on the canvas. */
async function loadSvg(fileId, svg, options) {
  if (typeof inlineSvgFonts === 'function') svg = await inlineSvgFonts(svg, svgFaces);
  const img = new Image();
  img.src = `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`;
  await img.decode();
  registerResourceImage(fileId, img, options);
  (loadImage.bytes ??= new Map()).set(fileId, new TextEncoder().encode(svg));
}

/** A face's Fontsource files: nearest weight; latin + what the SVG sets. */
async function svgFaces(family, weight, style, { codePoints = [] } = {}) {
  const [id, m] = [fontsourceId(family), await fontsourceMeta(family)];
  const w = m?.weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a)) ?? weight;
  const s = m?.styles.includes(style) === false ? 'normal' : style;
  return Promise.all(['latin', ...kitSubsetsFor(String.fromCodePoint(...codePoints), m)].map(async (x) => new Uint8Array(
    await (await fetch(`${await fontsourceAt(id)}files/${id}-${x}-${w}-${s}.woff2`)).arrayBuffer())));
}

/** 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 · cjk v2 ── Chinese, Japanese and Korean books · postext.dev/cookbook
// Fontsource ships a CJK family as about a hundred files per weight, each
// declared in its stylesheet with the unicode-range it covers. The screen
// loads the files the sample touches; the PDF gets the same files for the
// characters its pages set in each face, and embeds each as a subset.
// A book bound on the right (vertical text) is shown with its spreads
// mirrored: page 1 alone on the left of the spine, then [3 | 2].

/** The files of a Fontsource face, read from its stylesheet: { url, range,
 *  ranges }, the last declared first (the order the browser tries them in). */
function cjkSlices(family, weight, style) {
  cjkSlices.cache ??= new Map();
  const id = fontsourceId(family);
  const css = `${id}/${weight}${style === 'italic' ? '-italic' : ''}.css`;
  if (!cjkSlices.cache.has(css)) {
    let at;
    cjkSlices.cache.set(css, fontsourceAt(id).then((a) => fetch(at = a + css.slice(id.length + 1)))
      .then((res) => {
        if (!res.ok) throw new Error(`Fontsource has no ${family} ${weight} ${style} (${res.status})`);
        return res.text();
      })
      .then((text) => [...text.matchAll(/@font-face\s*{([^}]*)}/g)].map(([, rule]) => {
        const range = /unicode-range:\s*([^;]+);/.exec(rule)?.[1].trim() ?? 'U+0-10FFFF';
        const ranges = range.split(',').map((part) => {
          const [lo, hi = lo] = part.trim().slice(2).split('-');
          return [parseInt(lo, 16), parseInt(hi, 16)];
        });
        return { url: new URL(/url\(([^)]+?\.woff2)\)/.exec(rule)[1], at).href, range, ranges };
      }).reverse()));
  }
  return cjkSlices.cache.get(css);
}

/** The file of `slices` the screen sets code point `cp` in, if any: the
 *  last one loadCjkFonts adds whose range holds it. A numbered file that
 *  repeats a letter of latin is added after latin, and wins it. */
function cjkSliceFor(slices, cp) {
  const holds = (slice) => slice.ranges.some(([lo, hi]) => cp >= lo && cp <= hi);
  return slices.reduce((last, slice) => (holds(slice) ? slice : last), undefined);
}

/** Whether Fontsource serves `family` as a Chinese, Japanese or Korean
 *  family (its subsets name the script). Fails when the API does not
 *  answer: a CJK face taken for a Latin one would paint in a system face. */
async function isCjkFamily(family) {
  const meta = await fontsourceMeta(family);
  if (!meta) throw new Error(`api.fontsource.org did not describe ${family}: reload to try again`);
  return !!meta.subsets?.some((subset) => /^(chinese|japanese|korean)/.test(subset));
}

/** faces = { 'Noto Serif TC': ['400', '700'] }, as for loadFonts: the
 *  whole FONTS object may be passed, its other families are left to
 *  loadFonts. Adds one FontFace per file of each CJK face with its
 *  unicodeRange, then loads the files `text` touches. `text` is what the
 *  faces set: the sample for the text face; a book in several voices calls
 *  it once per voice (loadCjkFonts({ 'LXGW WenKai TC': ['400'] }, quotes)),
 *  so the heading and quotation faces fetch and check only their own
 *  characters. Fails when a character of `text` is in no file of a face.
 *  List every weight the pages use: a weight left to the engine's later round
 *  gets the latin file only. With { vertical: true } it also loads each
 *  family's vertical forms (brackets, quotes, pause marks) for the canvas,
 *  which needs loadVerticalAlternates imported from postext. Resolves to
 *  the number of files loaded. */
async function loadCjkFonts(faces, text, { vertical = false } = {}) {
  kitStatus('Loading fonts…');
  let loaded = 0;
  try {
    if (vertical && typeof loadVerticalAlternates !== 'function') {
      throw new Error('loadCjkFonts(…, { vertical: true }) needs loadVerticalAlternates imported from postext');
    }
    for (const [family, specs] of Object.entries(faces)) {
      if (!(await isCjkFamily(family))) continue;
      const twin = [];
      for (const spec of new Set(specs)) {
        const weight = parseInt(spec, 10);
        const style = spec.endsWith('i') ? 'italic' : 'normal';
        const slices = await cjkSlices(family, weight, style);
        const missing = [...new Set(text)].filter((ch) => /\S/.test(ch) && !cjkSliceFor(slices, ch.codePointAt(0)));
        if (missing.length) {
          throw new Error(`${family} ${spec} has no file for ${missing.slice(0, 12).join(' ')}: `
            + `give each face the text it sets (loadCjkFonts({ '${family}': ['${spec}'] }, text))`);
        }
        for (const slice of slices) {
          document.fonts.add(new FontFace(family, `url(${slice.url}) format('woff2')`,
            { weight: String(weight), style, unicodeRange: slice.range }));
          twin.push({ source: slice.url, weight: String(weight), style, unicodeRange: slice.range });
        }
        const font = `${style === 'italic' ? 'italic ' : ''}${weight} 16px "${family}"`;
        loaded += (await document.fonts.load(font, text)).length;
        if (!document.fonts.check(font, text)) throw new Error(`${family} ${spec} did not load for the sample`);
      }
      // The same files under a twin name with the `vert` feature on: the
      // canvas paints the punctuation of vertical lines with it.
      if (vertical && twin.length) await loadVerticalAlternates(family, twin);
    }
  } catch (error) {
    kitFail(error);
    throw error;
  }
  return loaded;
}

/** The PDF font provider for recipes with CJK faces: a family whose
 *  Fontsource subsets are Chinese, Japanese or Korean gets the files the
 *  screen set its pages' characters in (`request.codePoints`), each marked
 *  with its unicode-range and its place in the order loadCjkFonts added
 *  them: postext-pdf sets a character two files hold in the one added
 *  last, as the browser does. Any other family gets the latin file
 *  fontsourceProvider fetches (the "pdf" block) and, when the face sets
 *  letters only latin-ext has, that file too. */
async function cjkPdfProvider(family, weight, style, request) {
  if (!(await isCjkFamily(family))) return cjkLatinPdfFiles(family, weight, style, request);
  const meta = await fontsourceMeta(family);
  const weights = meta.weights?.length ? meta.weights : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const s = style === 'italic' && !meta.styles.includes('italic') ? 'normal' : style;
  const slices = await cjkSlices(family, w, s);
  const picked = new Set();
  for (const cp of request?.codePoints ?? []) {
    const slice = cjkSliceFor(slices, cp);
    if (slice) picked.add(slice);
  }
  if (!picked.size) picked.add(slices[0]);
  return Promise.all(slices.map(async (slice, order) => {
    if (!picked.has(slice)) return null;
    const res = await fetch(slice.url);
    if (!res.ok) throw new Error(`Fontsource file ${slice.url} (${res.status})`);
    const bytes = await decompressWoff2(new Uint8Array(await res.arrayBuffer()));
    return Object.assign(bytes, { unicodeRange: slice.range, order });
  })).then((files) => files.filter(Boolean));
}

/** A Latin family set next to the CJK faces: its latin file, then its
 *  latin-ext file when the face sets letters only latin-ext has (ō ū in
 *  Hepburn rōmaji, ǎ in pinyin), the file loadFonts adds on screen for
 *  them, each marked with its unicode-range and its place in that order:
 *  the PDF sets a character in the file the browser took it from. A face
 *  Fontsource ships without latin-ext, or whose file does not come, gets
 *  latin alone, and the PDF names the letters it lacks. */
async function cjkLatinPdfFiles(family, weight, style, request) {
  const meta = await fontsourceMeta(family);
  const beyond = [...(request?.codePoints ?? [])].some(cjkLatinExtOnly);
  if (!beyond || !meta?.subsets?.includes('latin-ext')) return fontsourceProvider(family, weight, style);
  const weights = meta.weights?.length ? meta.weights : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const s = style === 'italic' && !meta.styles.includes('italic') ? 'normal' : style;
  const id = fontsourceId(family);
  const url = `${await fontsourceAt(id)}files/${id}-latin-ext-${w}-${s}.woff2`;
  const [latin, ext] = await Promise.all([fontsourceProvider(family, weight, style), fetch(url)
    .then(async (res) => (res.ok ? decompressWoff2(new Uint8Array(await res.arrayBuffer())) : null), () => null)]);
  const ranges = kitRanges();
  return ext ? [Object.assign(latin, { unicodeRange: ranges.latin, order: 0 }),
    Object.assign(ext, { unicodeRange: ranges['latin-ext'], order: 1 })] : latin;
}

/** Whether code point `cp` is in Fontsource's latin-ext file and not in
 *  its latin file: Latin Extended-A and -B, IPA, the spacing modifiers and
 *  Latin Extended Additional (loadFonts's test for latin-ext), less the
 *  few latin holds too (ı Œ œ ʻ ʼ ˆ ˚ ˜). */
function cjkLatinExtOnly(cp) {
  if (!((cp >= 0x100 && cp <= 0x2ff) || (cp >= 0x1e00 && cp <= 0x1eff))) return false;
  return ![0x131, 0x152, 0x153, 0x2bb, 0x2bc, 0x2c6, 0x2da, 0x2dc].includes(cp);
}

/** showPages for a book bound on either edge. A right-bound book (the
 *  document says so: doc.binding is 'right' for page.binding 'right' and
 *  for vertical text) lies on the desk as it opens: page 1 alone on the
 *  left of the spine, then [3 | 2], the spine shade on each page's inner
 *  edge. `binding` ('left' | 'right') overrides the document's. */
function showBook(docs, { binding, ...options } = {}) {
  const count = showPages(docs, options);
  const right = (binding ?? [docs].flat()[0]?.binding) === 'right';
  if (!document.getElementById('pt-kit-cjk')) {
    // The pages keep direction ltr: a canvas draws text in the direction its
    // element inherits, and under rtl each run would end where the engine
    // starts it, its brackets mirrored.
    document.head.insertAdjacentHTML('beforeend', `<style id="pt-kit-cjk">
      .pt-spread[dir="rtl"] canvas { direction: ltr; }
      .pt-spread[dir="rtl"] 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); }
    </style>`);
  }
  // Each pair stays [verso, recto] in the page; right to left, the verso
  // sits on the right. Phones stack the pages in reading order either way.
  for (const spread of document.querySelectorAll('#pages > .pt-spread')) spread.dir = right ? 'rtl' : 'ltr';
  document.getElementById('pages').dataset.binding = right ? 'right' : 'left';
  return count;
}

// ─── /Kit ───────────────────────────────────────────────────────────────────────
```

## Variações

### Imprima o gabarito no fim do capítulo

Sem linhas `:::solutions`, `chapterEnd` reúne o gabarito de cada unidade antes do próximo título de nível 1.

```diff
-  solutions: { placement: edition === 'teacher' ? 'none' : 'directive' } });
+  solutions: { placement: edition === 'teacher' ? 'none' : 'chapterEnd' } });
```

### Escreva as leituras ao lado das lacunas

[A cartilha com pinyin](https://postext.dev/pt/cookbook/pinyin-primer.md) põe o pinyin sobre os caracteres como ruby, algo que uma lacuna ainda não comporta.

## Erros comuns

- **Fontes chinesas são carregadas em fatias, pelo bloco cjk.** O Fontsource serve uma família chinesa, japonesa ou coreana em cerca de cem arquivos por peso, cada um com um intervalo de caracteres. loadFonts baixa só o arquivo latin, então na tela os caracteres chineses vêm de uma fonte do sistema e são medidos errado, e o fontsourceProvider entrega ao PDF esse arquivo latin, que os imprime como caixas vazias. Inclua o bloco cjk do kit, chame loadCjkFonts(FONTS, markdown) depois de loadFonts (uma vez por voz, com o texto que ela compõe, quando o livro usa várias fontes CJK) e passe a renderToPdf fontProvider: cjkPdfProvider: os dois pegam os arquivos que contêm os caracteres do texto.

- Uma leitura ainda não pode ficar sobre uma lacuna: um ruby dentro de `[[…]]` faz parte da resposta oculta, e uma área de 田字格 ocupa toda a medida. A seção 看拼音写词语 põe cada sílaba numa linha própria e o quadrinho embaixo, quatro por fileira num grupo `:::columns`.
- A fonte Kai compõe só as respostas, então carrega apenas os caracteres das lacunas e das respostas modelo; um caractere que ela componha em outro lugar precisa ser acrescentado a esse texto.

## Créditos

- Receita: Ignacio Ferro ([@drnachio](https://github.com/drnachio))
- Imagens: A Chinese village in early spring: willows, swallows, peach blossom and two children on a path between rice fields.: Generated With Diffusion Models, original
- Imagens: Two children count oranges, apples and pears at a grandmother's fruit stall, a cat on a stool beside them.: Generated With Diffusion Models, original
- Tipos: Noto Serif SC (OFL-1.1), Noto Sans SC (OFL-1.1), LXGW WenKai TC (OFL-1.1)
- Código: MIT · Conteúdo de exemplo: CC-BY-4.0

## Relacionadas

- [Nº 161 · Caderno de caligrafia em dez escritas](https://postext.dev/pt/cookbook/handwriting-workbook.md): Um primeiro caderno de caligrafia em cada idioma do site: a letra escolar de cada país na sua pauta, um modelo, letras pontilhadas para cobrir e linhas vazias. · Nível 2 (Intermediário) · Cadernos de exercícios, Livros didáticos
- [Nº 076 · Uma cartilha com pinyin: a leitura sobre cada caractere](https://postext.dev/pt/cookbook/pinyin-primer.md): Rubi caractere a caractere numa cartilha de Hong Kong: {人之初|rén zhī chū} centraliza uma sílaba de pinyin sobre cada caractere, em Andika, num vão de 28 pt. · Nível 2 (Intermediário) · Livros didáticos, Cadernos de exercícios
- [Nº 173 · Um caderno de exercícios árabe, da direita para a esquerda](https://postext.dev/pt/cookbook/arabic-workbook-rtl.md): Um caderno árabe da direita para a esquerda: opções أ ب ج, colunas para ligar, banco de palavras, صح ou خطأ, caça-palavras e algarismos arábico-índicos. · Nível 2 (Intermediário) · Cadernos de exercícios, Livros didáticos