# Un quaderno di esercizi cinese, per alunno e insegnante

> Un 练习册 di cinese e matematica: sezioni 一、二、, parentesi （　）, 田字格 e operazioni in colonna, composto due volte da un solo testo, per l’alunno e l’insegnante.

- Versione HTML: https://postext.dev/it/cookbook/chinese-exercise-book
- Ricetta Nº 171 · Libri di testo · Livello 2 (Intermedio) · Output: Canvas, PDF
- Generi: Quaderni ed eserciziari, Libri di testo
- Richiede postext ≥ 1.59.0, postext-pdf ≥ 1.59.0 · provata con 1.59.0, postext-pdf 1.59.0 il 2026-10-24
- Pagine: [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)
- Apri nella Sandbox: https://postext.dev/it/sandbox#recipe=chinese-exercise-book&lang=zh (.postext: https://postext.dev/cookbook/chinese-exercise-book/zh/chinese-exercise-book.postext)
- Ultimo aggiornamento: 2026-10-24
- Altre lingue: [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), [pt](https://postext.dev/pt/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)

## In breve

Un quaderno di esercizi di una primaria cinese: due unità di lingua e di matematica. Lo stesso testo dà la copia dell’alunno, con spazi vuoti e soluzioni in fondo, e quella dell’insegnante, con ogni risposta in rosso al suo posto.

## Che cosa comporrai

Due unità di un 练习册 di seconda elementare in formato 16开: un’unità di lingua, 春天来了, e una di matematica su addizioni e sottrazioni entro il 100. Ognuna si apre con una fascia ad acquerello, una linguetta con la materia e una riga per classe, nome e punteggio, poi passa per le sezioni che stampa un quaderno cinese: 看拼音写词语, letture da cerchiare, 选择题 con una （　） dopo il testo e A. B. C. D. in fila, 判断题 con una parentesi a fine riga, frasi da completare, 连线 tra classificatori e oggetti, una frase da scrivere nei 田字格, 口算 su quattro colonne, 竖式 con una casella per cifra e un problema. I punti stanno in ogni consegna, dove li legge l’alunno. Lo stesso Markdown si compone due volte: il libro dell’alunno, con il 参考答案 alla fine di ogni unità, e quello dell’insegnante, con ogni risposta scritta in Kai rosso al suo posto.

**Questa ricetta risponde a:**

- Come compongo domande cinesi con una （　） dopo il testo e le opzioni A. B. C. D. in fila?
- Come ricavo la guida per l'insegnante, con le risposte al loro posto, dal libro dell'alunno?
- Come do a una domanda aperta la rigatura Seyès, i quadretti o le caselle 田字格 per scrivere?
- Come compongo la divisione in colonna come la scrivono le scuole di ogni paese?

## La risposta breve

```js
// script.js, righe 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' } });
```

## Ingredienti

**Insegna**

- [Stili di esercizio](https://postext.dev/it/docs/exercises.md#stili-degli-esercizi): exerciseStyles: come si stampa una famiglia di esercizi: il numero (cerchio, quadrato, etichetta), la consegna, le lettere delle opzioni, gli spazi vuoti, le caselle V/F, i punti da collegare, la banca di parole, gli spazi di scrittura, le griglie, le icone di attività e la difficoltà.
- [Guida per l'insegnante](https://postext.dev/it/docs/exercises.md#edizione-per-linsegnante): exercises.edition: 'teacher' stampa ogni risposta al suo posto in un secondo colore e cerchia le opzioni giuste: la guida per l'insegnante dal testo dell'alunno.
- [Scelta e vero o falso](https://postext.dev/it/docs/exercises.md#scelta-multipla-e-vero-o-falso): Scelta multipla da un elenco di attività (- [x] giusta, - [ ] sbagliata), con a) b) c), A. B. C., ア イ ウ o أ ب ج e una casella, un cerchio o una parentesi per rispondere; affermazioni vero o falso con le lettere della lingua.

**Usa anche**

- [Esercizi](https://postext.dev/it/docs/exercises.md#esercizi)
- [Spazi vuoti e banche di parole](https://postext.dev/it/docs/exercises.md#completamento-e-riquadro-di-parole)
- [Collegare e classificare](https://postext.dev/it/docs/exercises.md#collegamento-e-classificazione)
- [Domande aperte e spazi di scrittura](https://postext.dev/it/docs/exercises.md#domande-aperte-e-spazi-per-scrivere)
- [Operazioni in colonna](https://postext.dev/it/docs/exercises.md#operazioni-in-colonna)
- [Soluzioni](https://postext.dev/it/docs/exercises.md#soluzioni)
- [Numeri cinesi](https://postext.dev/it/docs/configuration-page-layout.md#numerazione)
- [Font cinesi, giapponesi e coreani](https://postext.dev/it/docs/configuration-pdf-output.md#font-cinesi-giapponesi-e-coreani)
- [Griglia dei caratteri](https://postext.dev/it/docs/configuration-east-asian.md#griglia-di-caratteri)
- [Punti di enfasi, linee dei nomi e dei titoli](https://postext.dev/it/docs/document-format-inline.md#segni-cinesi-ruby-e-warichu)
- [Chip in linea](https://postext.dev/it/docs/configuration-styles.md#stili-dei-chip)
- [Tre o più colonne](https://postext.dev/it/docs/configuration-page-layout.md#tipi-di-impaginazione)
- [Aperture progettate](https://postext.dev/it/docs/configuration-headings.md#estensione-e-grafica-avanzata)
- [Attributi dei titoli](https://postext.dev/it/docs/document-format.md#attributi-dei-titoli)
- [Immagini nei progetti di pagina](https://postext.dev/it/docs/configuration-headers-footers.md#elementi-immagine)
- [Tavolozza di colori semantica](https://postext.dev/it/docs/configuration-fonts-colors-viewers.md#tavolozza-dei-colori)
- [Esportazione in PDF](https://postext.dev/it/docs/configuration-pdf-output.md#generare-pdf)
- [Colonne in un riquadro o nel testo](https://postext.dev/it/docs/document-format-directives.md#columns)
- [Riquadri che si dividono o restano interi](https://postext.dev/it/docs/configuration-callouts.md#il-contenitore-callout)
- [Divisione in righe del cinese](https://postext.dev/it/docs/configuration-east-asian.md#tipografia-dellasia-orientale)
- [Bilanciamento delle colonne](https://postext.dev/it/docs/configuration-page-flow.md#bilanciamento-delle-colonne)
- [Stili di paragrafo](https://postext.dev/it/docs/configuration-styles.md#stili-di-paragrafo)
- [Font incorporati nel PDF](https://postext.dev/it/docs/configuration-pdf-output.md#perché-un-provider-di-font)
- [Figure e tabelle come risorse](https://postext.dev/it/docs/document-format-resources.md#risorse)

**La configurazione in breve**

- [`bodyText`](https://postext.dev/it/docs/configuration-text.md#testo-corrente), [`calloutStyles`](https://postext.dev/it/docs/configuration-callouts.md#stili-dei-riquadri), [`chipStyles`](https://postext.dev/it/docs/configuration-styles.md#stili-dei-chip), [`cjk`](https://postext.dev/it/docs/configuration-east-asian.md#tipografia-dellasia-orientale), [`colorPalette`](https://postext.dev/it/docs/configuration-fonts-colors-viewers.md#tavolozza-dei-colori), `exerciseStyles`, `exercises`, [`footer`](https://postext.dev/it/docs/configuration-headers-footers.md#intestazioni-e-piè-di-pagina), [`header`](https://postext.dev/it/docs/configuration-headers-footers.md#intestazioni-e-piè-di-pagina), [`headings`](https://postext.dev/it/docs/configuration-headings.md#titoli), [`layout`](https://postext.dev/it/docs/configuration-page-layout.md#impaginazione), [`locale`](https://postext.dev/it/docs/configuration-language.md#sillabazione), [`orderedLists`](https://postext.dev/it/docs/configuration-lists-math.md#elenchi-numerati), [`page`](https://postext.dev/it/docs/configuration-page-layout.md#pagina), [`paragraphStyles`](https://postext.dev/it/docs/configuration-styles.md#stili-di-paragrafo)

**API**

- [`buildDocument`](https://postext.dev/it/docs/configuration-programmatic-usage.md#costruire-un-documento), [`decompressWoff2`](https://postext.dev/it/docs/configuration-pdf-output.md#provider-di-font-per-il-browser-fontsource--woff2), [`registerResourceImage`](https://postext.dev/it/docs/architecture.md#superficie-dellapi), [`renderPageToCanvas`](https://postext.dev/it/docs/configuration-programmatic-usage.md#rasterizzare-una-pagina), [`renderToPdf`](https://postext.dev/it/docs/configuration-pdf-output.md#generare-pdf), [`withLoadedFonts`](https://postext.dev/it/docs/configuration-programmatic-usage.md#caricare-i-font-prima-dellimpaginazione)

**Caratteri**

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

## Preparazione

### 1 · Un solo stile per tutte le sezioni

Il codice è nella [risposta breve](https://postext.dev/it/cookbook/chinese-exercise-book.md#la-risposta-breve) qui sopra. Le sezioni si contano con numerali cinesi seguiti da un 、 a larghezza piena, quindi dopo il numero non c’è spazio; la consegna è in Hei senza grassetto, così i punti tra parentesi si leggono come parte di essa. `options.bracket` scrive la （　） dopo ogni testo, e nel libro dell’insegnante la lettera giusta ci va dentro. I due stili piccoli estendono quello principale: `pinyin` disegna ogni spazio vuoto come una casella larga quanto la sua parola, `kuohao` non disegna nulla, perché la parentesi di 在（　）里填 è già nel testo.

### 2 · Il libro dell’alunno e quello dell’insegnante da un solo testo

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

La configurazione è una funzione, quindi ogni composizione riceve il suo oggetto e il pacchetto del Sandbox conserva quello dell’alunno. `edition: 'teacher'` scrive le risposte nel colore e nel carattere di `answers`: le parole nelle loro caselle, le lettere nelle loro parentesi, √ e × nei 判断题, le cifre nelle caselle dei 竖式, la frase modello con un carattere per quadretto. Il libro dell’alunno tiene le soluzioni per la riga `:::solutions` alla fine di ogni unità; quello dell’insegnante non ne ha bisogno.

### 3 · Un’apertura di unità con il suo dipinto

```js
// script.js, righe 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' } } },
] } };
```

Il dipinto è ancorato alla pagina, quindi arriva al bordo superiore sia su un recto sia su un verso; la linguetta e il titolo si collocano dall’alto della gabbia di testo, sotto il piede del dipinto. Le due unità condividono il progetto grafico e cambiano solo negli attributi del titolo, `kicker` e `pic`.

### 4 · Numeri di pagina al piede

```js
// script.js, righe 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' }),
] };
```

I quaderni cinesi mettono il numero di pagina al piede. Il titolo della collana viene dal front matter del Markdown (`{title}`), quello dell’unità dal suo titolo (`{chapterTitle}`).

## La ricetta completa

Un unico file, composto a partire dalla cartella della ricetta con il testo di esempio e il kit comune del Ricettario già inclusi; costruisce la propria pagina. Per eseguirlo, mettilo in uno `<script type="module">` di una pagina vuota, oppure incollalo nel pannello JS di un nuovo pen di CodePen (come modulo). Importa postext da esm.sh: non c’è niente da installare né da compilare.

- Cartella della ricetta: 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 ───────────────────────────────────────────────────────────────────────
```

## Varianti

### Stampa le soluzioni a fine capitolo

Senza righe `:::solutions`, `chapterEnd` raccoglie le soluzioni di ogni unità prima del titolo di livello 1 successivo.

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

### Scrivi le letture accanto agli spazi vuoti

[L’abbecedario in pinyin](https://postext.dev/it/cookbook/pinyin-primer.md) mette il pinyin sopra i suoi caratteri come ruby, cosa che uno spazio vuoto non può ancora contenere.

## Errori frequenti

- **I caratteri cinesi si caricano a fette, tramite il blocco cjk.** Fontsource serve una famiglia cinese, giapponese o coreana come un centinaio di file per peso, ognuno dei quali copre un intervallo di caratteri. loadFonts scarica solo il file latin, così a schermo i caratteri Han vengono da un font di sistema e sono misurati male, e fontsourceProvider passa al PDF quel file latin, che li stampa come riquadri vuoti. Elenca il blocco cjk del kit, chiama loadCjkFonts(FONTS, markdown) dopo loadFonts (una volta per voce tipografica, con il testo che compone, quando il libro usa più caratteri CJK) e passa a renderToPdf fontProvider: cjkPdfProvider: entrambi prendono i file che contengono i caratteri del testo.

- Una lettura non può ancora stare sopra uno spazio vuoto: un ruby dentro `[[…]]` fa parte della risposta nascosta, e un’area di 田字格 occupa tutta la giustezza. La sezione 看拼音写词语 mette ogni sillaba su una riga sua e la casella sotto, quattro per fila in un gruppo `:::columns`.
- Il carattere Kai compone solo le risposte, quindi carica soltanto i caratteri degli spazi vuoti e delle risposte modello; se compone un carattere altrove, va aggiunto a quel testo.

## Crediti

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

## Ricette correlate

- [Nº 161 · Quaderno di scrittura in dieci grafie scolastiche](https://postext.dev/it/cookbook/handwriting-workbook.md): Un primo quaderno di scrittura in ogni lingua del sito: la grafia scolastica di ogni paese sulla sua rigatura, un modello, lettere da ripassare e righe vuote. · Livello 2 (Intermedio) · Quaderni ed eserciziari, Libri di testo
- [Nº 076 · Un sillabario in pinyin: la lettura sopra ogni carattere](https://postext.dev/it/cookbook/pinyin-primer.md): Ruby mono in un primo libro di lettura di Hong Kong: {人之初|rén zhī chū} centra una sillaba pinyin su ogni carattere, in Andika, nei 28 pt tra le righe. · Livello 2 (Intermedio) · Libri di testo, Quaderni ed eserciziari
- [Nº 173 · Un quaderno di esercizi arabo, da destra a sinistra](https://postext.dev/it/cookbook/arabic-workbook-rtl.md): Un quaderno arabo per la primaria da destra a sinistra: opzioni أ ب ج, colonne da collegare, riquadro di parole, صح o خطأ, crucipuzzle e cifre arabo-indiane. · Livello 2 (Intermedio) · Quaderni ed eserciziari, Libri di testo