# 从右向左排的阿拉伯文练习册

> 一册从右向左排的阿拉伯文小学练习册：أ ب ج选项、两栏连线、词语框、صح或خطأ判断框、找词方阵，编号用阿拉伯-印度数字。

- HTML版本: https://postext.dev/zh/cookbook/arabic-workbook-rtl
- 食谱 No. 173 · 教科书 · 难度 2 (中级) · 输出: Canvas, PDF
- 体裁: 练习册与习题, 教科书
- 需要 postext ≥ 1.59.0, postext-pdf ≥ 1.59.0 · 已用 1.59.0, postext-pdf 1.59.0 测试，日期 2026-10-24
- 页面: [١](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p01.webp?v=cd08e1dc), [٢](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p02.webp?v=cd08e1dc), [٣](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p03.webp?v=cd08e1dc), [٤](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p04.webp?v=cd08e1dc), [1](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p05.webp?v=cd08e1dc), [2](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p06.webp?v=cd08e1dc), [3](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p07.webp?v=cd08e1dc), [4](https://postext.dev/cookbook/arabic-workbook-rtl/ar/p08.webp?v=cd08e1dc)
- 在沙盒中打开: https://postext.dev/zh/sandbox#recipe=arabic-workbook-rtl&lang=ar (.postext: https://postext.dev/cookbook/arabic-workbook-rtl/ar/arabic-workbook-rtl.postext)
- 最后更新: 2026-10-24
- 其他语言: [en](https://postext.dev/en/cookbook/arabic-workbook-rtl.md), [es](https://postext.dev/es/cookbook/arabic-workbook-rtl.md), [ca](https://postext.dev/ca/cookbook/arabic-workbook-rtl.md), [de](https://postext.dev/de/cookbook/arabic-workbook-rtl.md), [fr](https://postext.dev/fr/cookbook/arabic-workbook-rtl.md), [it](https://postext.dev/it/cookbook/arabic-workbook-rtl.md), [pt](https://postext.dev/pt/cookbook/arabic-workbook-rtl.md), [ja](https://postext.dev/ja/cookbook/arabic-workbook-rtl.md), [ar](https://postext.dev/ar/cookbook/arabic-workbook-rtl.md)

## 简单来说

一本阿拉伯文儿童练习册里讲学校菜园的几页：选出答案、两栏连线、用框里的词填空、判断对错、给词语排序，在字母方阵里找词。

## 成品一览

阿拉伯文二年级练习册中的一个单元，页面17 × 24 cm，主题是学校菜园。单元以一条水彩画开篇，下面是单元标签和标题，姓名、班级、日期各一条点线。接着是阿拉伯小学课本常印的几类练习：选出正确答案，أ) ب) ج)每行三个；两栏连线；用词语框里的词填空；判断صح或خطأ；给词语排序，再把句子写在线上；在字母方阵里找出七个菜园里的词。单元最后是答案。同一份文本排两次：马什里克版的编号全用阿拉伯-印度数字١ ٢ ٣，马格里布版用欧洲数字。两版都从右边读起，都在右侧装订。

**这份食谱回答的问题:**

- 怎样让阿拉伯文练习册从右向左排，并带连线题、找词方阵和阿拉伯-印度数字？
- 怎样排一页练习册：圆圈题号、词库、判断题、连线题？
- 怎样用一组词语生成找词游戏或填字游戏？

## 简短回答

```js
// script.js, 行 34–53
// The locale sets the direction, the binding and the digits: 'ar' writes the exercise
// numbers, the items and the key in Arabic-Indic digits (١ ٢ ٣), 'ar-MA' in European ones.
// Options take the abjad letters (أ ب ج), true/false the words صح / خطأ, both from the
// language. Nothing below names a side: the engine sets every part from the right.
const tamrin = {
  id: 'tamrin',
  number: { shape: 'disc', fontFamily: LABEL, background: col('accent') },
  instruction: { fontFamily: LABEL, bold: false, color: col('ink') },
  options: { layout: 'row' }, // أ) ب) ج) side by side, three to a row (columns=3)
  blank: { look: 'dots', color: col('muted') }, // a dotted line, as Arab workbooks print it
  match: { color: col('accent') },
  bank: { box: 'sunduq', order: 'shuffle' },
  area: { kind: 'lines', color: col('rule') },
  grid: { fontFamily: TEXT, rule: col('leaf'), uppercase: false }, // Arabic has no capitals
  answers: { color: col('leaf'), fontFamily: TEXT },
  solutions: { box: 'hulul' },
  marginTop: em(1.1), marginBottom: em(0.5),
};
// The solutions where :::solutions stands: at the end of the unit.
const exercises = { solutions: { placement: 'directive' } };
```

## 用料

**讲解**

- [练习](https://postext.dev/zh/docs/exercises.md#练习): :::exercise 围栏：题干、小题和答案都写在 Markdown 中的练习，按练习样式编号和排版，纸面与屏幕一致。
- [从右向左的文字](https://postext.dev/zh/docs/arabic-layout.md#文字方向与双向算法): direction设定文档的基本方向：默认值'auto'按locale的文字决定，所以'ar'、'fa'或'he'从右向左排；双向算法（UAX #9）安排每行中拉丁词和数字的顺序，书改为右翻。
- [生成数字所用的数码](https://postext.dev/zh/docs/configuration-language.md#文档语言): numerals（'auto'、'latn'、'arab'、'arabext'）决定引擎写出的所有数字用哪套数码：页码、列表和注释编号、标题和图的编号、目录和索引中的页码。'auto'跟随locale：阿拉伯文用١٢٣，马格里布地区（ar-MA、ar-DZ、ar-TN）用1 2 3。作者自己写的文字不会被改动。

**还用到**

- [练习样式](https://postext.dev/zh/docs/exercises.md#练习样式)
- [选择题与判断题](https://postext.dev/zh/docs/exercises.md#选择题与判断题)
- [填空与词库](https://postext.dev/zh/docs/exercises.md#填空题与词库)
- [连线与分类](https://postext.dev/zh/docs/exercises.md#连线题与分类题)
- [排序](https://postext.dev/zh/docs/exercises.md#排序)
- [找词游戏与填字游戏](https://postext.dev/zh/docs/exercises.md#找词游戏与填字游戏)
- [答案](https://postext.dev/zh/docs/exercises.md#答案与解答)
- [阿拉伯文字体](https://postext.dev/zh/docs/arabic-layout.md#字体)
- [阿拉伯文编号样式](https://postext.dev/zh/docs/arabic-layout.md#数字系统与编号样式)
- [右翻书](https://postext.dev/zh/docs/configuration-page-layout.md#装订)
- [行内标签](https://postext.dev/zh/docs/configuration-styles.md#行内标签样式)
- [标注框](https://postext.dev/zh/docs/configuration-callouts.md#标注框样式)
- [设计过的章首页](https://postext.dev/zh/docs/configuration-headings.md#通栏与高级设计)
- [标题属性](https://postext.dev/zh/docs/document-format.md#标题属性)
- [页面设计中的图片](https://postext.dev/zh/docs/configuration-headers-footers.md#图像元素)
- [语义调色板](https://postext.dev/zh/docs/configuration-fonts-colors-viewers.md#调色板)
- [导出PDF](https://postext.dev/zh/docs/configuration-pdf-output.md#生成pdf)
- [拆分或保持完整的框](https://postext.dev/zh/docs/configuration-callouts.md#callout容器)
- [各栏齐底](https://postext.dev/zh/docs/configuration-page-flow.md#各栏齐底)
- [开放题与书写区](https://postext.dev/zh/docs/exercises.md#问答题与书写区)
- [按页面角色显示书眉](https://postext.dev/zh/docs/configuration-headers-footers.md#文本元素)
- [段落样式](https://postext.dev/zh/docs/configuration-styles.md#段落样式)
- [嵌入PDF的字体](https://postext.dev/zh/docs/configuration-pdf-output.md#为什么需要字体提供函数)
- [作为资源的图和表](https://postext.dev/zh/docs/document-format-resources.md#资源)

**配置一览**

- [`bodyText`](https://postext.dev/zh/docs/configuration-text.md#正文), [`calloutStyles`](https://postext.dev/zh/docs/configuration-callouts.md#标注框样式), [`chipStyles`](https://postext.dev/zh/docs/configuration-styles.md#行内标签样式), [`colorPalette`](https://postext.dev/zh/docs/configuration-fonts-colors-viewers.md#调色板), `exerciseStyles`, `exercises`, [`footer`](https://postext.dev/zh/docs/configuration-headers-footers.md#页眉与页脚), [`header`](https://postext.dev/zh/docs/configuration-headers-footers.md#页眉与页脚), [`headings`](https://postext.dev/zh/docs/configuration-headings.md#标题), [`layout`](https://postext.dev/zh/docs/configuration-page-layout.md#版式), [`locale`](https://postext.dev/zh/docs/configuration-language.md#断词), [`orderedLists`](https://postext.dev/zh/docs/configuration-lists-math.md#有序列表), [`page`](https://postext.dev/zh/docs/configuration-page-layout.md#页面), [`paragraphStyles`](https://postext.dev/zh/docs/configuration-styles.md#段落样式)

**API**

- [`buildDocument`](https://postext.dev/zh/docs/configuration-programmatic-usage.md#构建文档), [`decompressWoff2`](https://postext.dev/zh/docs/configuration-pdf-output.md#浏览器字体提供函数fontsource--woff2), [`registerResourceImage`](https://postext.dev/zh/docs/architecture.md#api接口), [`renderPageToCanvas`](https://postext.dev/zh/docs/configuration-programmatic-usage.md#把页面渲染为位图), [`renderToPdf`](https://postext.dev/zh/docs/configuration-pdf-output.md#生成pdf), [`withLoadedFonts`](https://postext.dev/zh/docs/configuration-programmatic-usage.md#排版前加载字体)

**字体**

- Noto Naskh Arabic (OFL-1.1), Baloo Bhaijaan 2 (OFL-1.1)

## 做法

### 1 · 不写哪一边

代码见上文的[简短回答](https://postext.dev/zh/cookbook/arabic-workbook-rtl.md#简短回答)。`locale: 'ar'`让文字从右向左排，让书在右侧装订，并选定数字；练习样式从语言里取出选项用的abjad字母，以及判断题用的صح和خطأ。连线的两栏、词语框、找词方阵和书写线都画成框的设计，从右向左的页面会把它们镜像过来：第一栏在右边，方阵里横读的词从右往左走，连线的点在中间相对。

### 2 · 菜园开篇

```js
// script.js, 行 58–73
const BAND = 170 / 2.4; // mm: the painting's height at the page's width
const opener = { enabled: true, minHeight: mm(BAND - 20 + 21), slot: { elements: [
  { kind: 'image', id: 'picture', resourceId: '{attr.pic}', decorative: true, reserve: false,
    placement: { anchor: { to: 'page', edge: 'top-left' },
      size: { width: mm(170), height: mm(BAND) } } },
  // In the flow of a right-to-left page 'left' is the start of the line: the right.
  { kind: 'text', id: 'unit', content: '{attr.kicker}', fontFamily: LABEL, fontSize: pt(11),
    fontWeight: 700, color: col('paper'), align: 'left',
    box: { backgroundColor: col('accent'), borderRadius: mm(1.5),
      padding: { top: mm(0.6), bottom: mm(0.4), left: mm(2.4), right: mm(2.4) } },
    placement: { anchor: { to: 'container', edge: 'top-left' },
      offset: { x: mm(0), y: mm(BAND - 20 + 3) } } },
  { kind: 'text', id: 'title', content: '{titleText}', fontFamily: LABEL, fontSize: pt(30),
    fontWeight: 700, color: col('ink'), align: 'left',
    placement: { anchor: { to: '#unit', edge: 'right-of' }, offset: { x: mm(4), y: mm(-5) } } },
] } };
```

画固定在页面上，位置不变。标签和标题放在页面的排版流里，`left`在这里指行首，所以它们不用自己的坐标就落在右边。页码和书眉一样按实际页面放置，左右两侧分别写明。

### 3 · 两个版本，两套数字

```js
// script.js, 行 227–232
// Both are bound on the right and read from the right; only the locale changes.
const build = () => withLoadedFonts(() => buildDocument({ markdown, resources }, config()),
  { ...kitFonts(FONTS), text: markdown });
const mashriq = await build();
edition = { locale: 'ar-MA' }; // the same book for Morocco: European digits, still right to left
const docs = [mashriq, await build()];
```

配置是一个函数，每次排版都得到自己的对象，第二次只换语言。`ar-MA`把练习编号、小题、答案和页码写成欧洲数字，其余保持不变：文字方向、装订、abjad字母，以及答案里的词。

## 完整食谱

一个文件，由食谱文件夹合成，示例文本和排版食谱的公共工具包都已内联；它自己排出页面。要运行它，把它放进空白页面的`<script type="module">`，或粘贴到新建CodePen的JS面板里（设为模块）。它从esm.sh导入postext，不需要安装或构建。

- 食谱文件夹: https://github.com/drnachio/postext/tree/main/cookbook/arabic-workbook-rtl

### script.js

```js
// ═══ Postext Cookbook · Nº 173 · An Arabic workbook, right to left ═══════════════
// https://postext.dev/en/cookbook/arabic-workbook-rtl
// Code: MIT · Text: original (CC BY 4.0) · Pictures: generated with diffusion models
// Fonts: Noto Naskh Arabic, Baloo Bhaijaan 2 (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 = 'ar'; // @lang: the language of the frame; the workbook is Arabic in all
const RECIPE = 'arabic-workbook-rtl';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
// #region palette: a garden workbook: ink, a terracotta accent, a leaf green, sand
const palette = {
  ink: '#22282e', // text
  accent: '#b9542a', // the one accent: exercise numbers, the unit tab, the word bank
  leaf: '#4f7d3a', // the second: rules and the word search's ruling
  sand: '#f8eedf', // the bank's ground, the answers box
  rule: '#c8b49b', // writing lines
  muted: '#6f655c', // folios, the name line, the colophon
  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.accent, model: 'hex' } },
];
// #endregion
// Naskh for the text, a rounded Arabic for the labels a child reads first.
const [TEXT, LABEL] = ['Noto Naskh Arabic', 'Baloo Bhaijaan 2'];

// #region answer: one exercise style read right to left, in the edition's digits
// The locale sets the direction, the binding and the digits: 'ar' writes the exercise
// numbers, the items and the key in Arabic-Indic digits (١ ٢ ٣), 'ar-MA' in European ones.
// Options take the abjad letters (أ ب ج), true/false the words صح / خطأ, both from the
// language. Nothing below names a side: the engine sets every part from the right.
const tamrin = {
  id: 'tamrin',
  number: { shape: 'disc', fontFamily: LABEL, background: col('accent') },
  instruction: { fontFamily: LABEL, bold: false, color: col('ink') },
  options: { layout: 'row' }, // أ) ب) ج) side by side, three to a row (columns=3)
  blank: { look: 'dots', color: col('muted') }, // a dotted line, as Arab workbooks print it
  match: { color: col('accent') },
  bank: { box: 'sunduq', order: 'shuffle' },
  area: { kind: 'lines', color: col('rule') },
  grid: { fontFamily: TEXT, rule: col('leaf'), uppercase: false }, // Arabic has no capitals
  answers: { color: col('leaf'), fontFamily: TEXT },
  solutions: { box: 'hulul' },
  marginTop: em(1.1), marginBottom: em(0.5),
};
// The solutions where :::solutions stands: at the end of the unit.
const exercises = { solutions: { placement: 'directive' } };
// #endregion


// #region opener: the garden to the bleed, the unit's tab and its title under it
const BAND = 170 / 2.4; // mm: the painting's height at the page's width
const opener = { enabled: true, minHeight: mm(BAND - 20 + 21), slot: { elements: [
  { kind: 'image', id: 'picture', resourceId: '{attr.pic}', decorative: true, reserve: false,
    placement: { anchor: { to: 'page', edge: 'top-left' },
      size: { width: mm(170), height: mm(BAND) } } },
  // In the flow of a right-to-left page 'left' is the start of the line: the right.
  { kind: 'text', id: 'unit', content: '{attr.kicker}', fontFamily: LABEL, fontSize: pt(11),
    fontWeight: 700, color: col('paper'), align: 'left',
    box: { backgroundColor: col('accent'), borderRadius: mm(1.5),
      padding: { top: mm(0.6), bottom: mm(0.4), left: mm(2.4), right: mm(2.4) } },
    placement: { anchor: { to: 'container', edge: 'top-left' },
      offset: { x: mm(0), y: mm(BAND - 20 + 3) } } },
  { kind: 'text', id: 'title', content: '{titleText}', fontFamily: LABEL, fontSize: pt(30),
    fontWeight: 700, color: col('ink'), align: 'left',
    placement: { anchor: { to: '#unit', edge: 'right-of' }, offset: { x: mm(4), y: mm(-5) } } },
] } };
// #endregion

// Folios at the foot's outer corner: running heads stay physical, so each side is named.
const foot = (id, content, parity, edge, x, extra = {}) => ({ kind: 'text', id, content, parity,
  pages: 'body', fontFamily: LABEL, fontSize: pt(9), color: col('muted'),
  placement: { anchor: { to: 'page', edge }, offset: { x: mm(x), y: mm(-11) } }, ...extra });
const footer = { elements: [
  foot('folio-v', '{pageNumber}', 'even', 'bottom-left', 16,
    { fontWeight: 700, color: col('accent') }),
  foot('title-v', '{title}', 'even', 'bottom-left', 24),
  foot('folio-r', '{pageNumber}', 'odd', 'bottom-right', -16,
    { fontWeight: 700, color: col('accent'), align: 'right' }),
  foot('title-r', '{chapterTitle}', 'odd', 'bottom-right', -24, { align: 'right' }),
] };

let edition = {}; // what the second build below changes: the Maghreb edition's locale
const config = () => ({
  locale: 'ar', // the Mashriq edition: ١ ٢ ٣
  colorPalette,
  exerciseStyles: [tamrin],
  exercises,
  page: { sizePreset: 'custom', width: mm(170), height: mm(240), dpi: 150,
    margins: { top: mm(20), bottom: mm(20), left: mm(18), right: mm(16), mirror: true } },
  layout: { layoutType: 'single' },
  bodyText: { fontFamily: TEXT, fontSize: pt(13), lineHeight: pt(22), color: col('ink'),
    boldColor: col('ink'), italicColor: col('ink'), referenceColor: col('ink'),
    textAlign: 'justify', firstLineIndent: pt(0), hyphenation: { enabled: false },
    avoidWidows: true, avoidOrphans: true },
  headings: { fontFamily: LABEL, color: col('ink'), fontWeight: 700,
    balancing: { enabled: false },
    levels: [{ level: 1, fontSize: pt(30), breakBefore: { parity: 'any' },
      advancedDesign: opener }] },
  orderedLists: { numberFormat: 'arabic', color: col('ink'), fontWeight: 700 },
  paragraphStyles: [
    { id: 'ism', fontFamily: LABEL, fontSize: pt(11), color: col('muted'), firstLineIndent: pt(0),
      textAlign: 'left', marginBottom: mm(3) },
    { id: 'colophon', fontFamily: LABEL, fontSize: pt(8), lineHeight: pt(13), color: col('muted'),
      textAlign: 'left', firstLineIndent: pt(0), marginTop: mm(6) },
  ],
  chipStyles: [{ id: 'khatt', backgroundEnabled: false, underline: 'dotted', borderWidth: pt(1),
    borderColor: col('muted'), minWidth: mm(26), paddingX: pt(0), paddingY: pt(0) }],
  calloutStyles: [
    { id: 'sunduq', background: col('sand'), border: { enabled: true, color: col('accent'),
      width: pt(1), style: 'dashed' }, borderRadius: mm(2.5),
    padding: { top: mm(2), right: mm(4), bottom: mm(2.5), left: mm(4) },
    body: { fontFamily: LABEL, fontSize: pt(12), textAlign: 'center' },
    marginTop: mm(1.5), marginBottom: mm(2.5) },
    { id: 'hulul', background: col('sand'), borderRadius: mm(2),
      stripe: { enabled: true, side: 'left', width: pt(3), color: col('leaf') },
      padding: { top: mm(3), right: mm(4), bottom: mm(3.5), left: mm(4) },
      titleStyle: { fontFamily: LABEL, fontSize: pt(13), fontWeight: 700, color: col('leaf') },
      body: { fontSize: pt(11), lineHeight: pt(19), color: col('ink'), firstLineIndent: pt(0) },
      marginTop: mm(6), marginBottom: mm(2), keepTogether: false },
  ],
  header: { elements: [] },
  footer,
  ...edition,
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
title: "كراسة التمارين · الصف الثاني"
---

# في الحديقة {kicker="الوحدة الثالثة" pic="garden"}

:::paragraphs{style="ism"}
الاسم: :chip[ ]{style="khatt"}  الصف: :chip[ ]{style="khatt"}  التاريخ: :chip[ ]{style="khatt"}
:::

:::exercise{columns=3}
اخترِ الإجابة الصحيحة.

1. تحتاج النبتة كي تنمو إلى:
   - [ ] الحجارة
   - [x] الماء
   - [ ] الرمل
2. نسقي الحديقة في الصباح الباكر لأنّ الشمس فيه:
   - [x] ليست حارّة
   - [ ] شديدة الحرارة
   - [ ] غائبة
3. يصنع النحل العسل من:
   - [ ] أوراق الشجر
   - [ ] حبّات التراب
   - [x] رحيق الأزهار
:::

:::exercise
صِلْ كلّ كلمة في العمود الأول بما يناسبها في العمود الثاني.

- النحلة -> تصنع العسل
- الشمس -> تمنح الضوء والدفء
- الجذور -> تمتصّ الماء من التربة
- الفراشة -> تنتقل من زهرة إلى زهرة
:::

:::exercise{bank}
أكمِلِ الفراغ بالكلمة المناسبة من الصندوق.

زرعت سلمى بذرة [[الليمون]] في أصيص صغير، ووضعته قرب [[النافذة]] حتى يصله الضوء، وصارت [[تسقيه]] كلّ يومين. وبعد أسبوعين ظهرت ورقتان [[خضراوان]].

::bank[الملح | السيّارة]
:::

:::exercise{type=truefalse}
ضع علامة في المربّع المناسب.

- [x] تصنع النحلة العسل من رحيق الأزهار.
- [ ] تنمو شجرة الليمون في يوم واحد.
- [x] الجذور تثبّت النبتة في التربة.
- [ ] نسقي النباتات بالحليب.
:::

:::exercise{type=scramble}
رتّبِ الكلمات لتكوّن جملة مفيدة، ثمّ اكتبها على السطر.

- تسقي / سلمى / الأزهار / في / الصباح
- يحمل / خالد / أصيص / النعناع
:::

:::exercise{type=wordsearch size=8}
ابحث في الشبكة عن أسماء الأشياء التي نراها في الحديقة، ثمّ لوّنها.

- شجرة
- زهرة
- تربة
- بذرة
- ورقة
- نحلة
- غصن
:::

:::solutions

:::paragraphs{style="colophon"}
الحروف: Noto Naskh Arabic وBaloo Bhaijaan 2 (رخصة SIL OFL) · الرسم: مولَّد بنماذج الانتشار · التمارين: نصّ أصليّ للكتاب (CC BY 4.0)
:::
`; // content.ar.md: one text for both editions

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
const FONTS = {
  'Noto Naskh Arabic': ['400', '700'], // the text, the word search's letters
  'Baloo Bhaijaan 2': ['400', '700'], // instructions, numbers, the title
};

// ─── 4 · Build & show ───────────────────────────────────────────────────────
await loadFonts(FONTS, markdown);
// Each Arabic face's letters live in a file of their own (gotcha: arabic-fonts-subset).
await loadArabicFonts(FONTS, markdown);
await loadImage('garden-1600.jpg', asset('garden-1600.jpg'));
const resources = [{ id: 'garden', typeId: 'figure', kind: 'bitmap', createdAt: 0, updatedAt: 0,
  bitmap: { fileId: 'garden-1600.jpg', format: 'jpeg', width: 1600, height: 667 } }];
// #region editions: one text, two editions: Mashriq digits, then Maghreb digits
// Both are bound on the right and read from the right; only the locale changes.
const build = () => withLoadedFonts(() => buildDocument({ markdown, resources }, config()),
  { ...kitFonts(FONTS), text: markdown });
const mashriq = await build();
edition = { locale: 'ar-MA' }; // the same book for Morocco: European digits, still right to left
const docs = [mashriq, await build()];
// #endregion
showBook(docs, { title: t({ ar: 'كراسة تمارين عربية', en: 'An Arabic workbook, right to left',
  es: 'Un cuaderno de ejercicios árabe, de derecha a izquierda' }) });
offerPdf(() => renderToPdf(docs, { fontProvider: arabicPdfProvider, 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 · arabic v2 ── Arabic-script faces · postext.dev/cookbook
// Fontsource ships an Arabic family as one file per subset and weight: the
// `arabic` file holds the letters, the harakat, the Arabic-Indic digits, the
// Arabic punctuation and the presentation forms; `latin` and `latin-ext`
// hold the rest. loadFonts loads the latin files; this block adds the arabic
// file of every Arabic family, for the canvas and for the PDF, which shapes
// the letters with HarfBuzz from the same bytes.

/** The code points of Fontsource's `arabic` subset, as its stylesheets
 *  declare them (the same unicode-range the browser picks the file by). A
 *  function, not a const: the kit is inlined after the recipe's top-level
 *  awaits, and a const read before its line throws, where a function
 *  declaration is hoisted. */
function arabicRange() {
  return 'U+0600-06FF,U+0750-077F,U+0870-088E,U+0890-0891,U+0897-08E1,U+08E3-08FF,'
    + 'U+200C-200E,U+2010-2011,U+204F,U+2E41,U+FB50-FDFF,U+FE70-FE74,U+FE76-FEFC,U+102E0-102FB,'
    + 'U+10E60-10E7E,U+10EC2-10EC4,U+10EFC-10EFF,U+1EE00-1EEFF';
}

/** Whether code point `cp` is in the arabic file. */
function inArabicRange(cp) {
  inArabicRange.ranges ??= arabicRange().split(',').map((part) => {
    const [lo, hi = lo] = part.slice(2).split('-');
    return [parseInt(lo, 16), parseInt(hi, 16)];
  });
  return inArabicRange.ranges.some(([lo, hi]) => cp >= lo && cp <= hi);
}

/** Whether Fontsource serves `family` with an `arabic` subset. Fails when
 *  the API does not answer: an Arabic face taken for a Latin one would set
 *  its letters in a system face. */
async function isArabicFamily(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?.includes('arabic');
}

/** The arabic file of a face. */
async function arabicFileUrl(family, weight, style) {
  const id = fontsourceId(family);
  return `${await fontsourceAt(id)}files/${id}-arabic-${weight}-${style}.woff2`;
}

/** faces = { Amiri: ['400', '700'] }, as for loadFonts, after it: the whole
 *  FONTS object may be passed, its families without an arabic subset are
 *  left alone. Adds the arabic file of every listed weight of each Arabic
 *  family (the latin files come from loadFonts) and loads it. `text` is
 *  the sample: fails when it holds an Arabic-script character the arabic
 *  file does not cover. List every weight the pages set in Arabic: a weight
 *  left to the engine's later round gets the latin file only, and its Arabic letters
 *  fall back to a system face. Resolves to the number of files loaded. */
async function loadArabicFonts(faces, text = '') {
  kitStatus('Loading fonts…');
  let loaded = 0;
  try {
    const outside = [...new Set(text)].filter((ch) => /\p{Script=Arabic}/u.test(ch) && !inArabicRange(ch.codePointAt(0)));
    if (outside.length) throw new Error(`Fontsource's arabic files have no ${outside.slice(0, 12).join(' ')}`);
    for (const [family, specs] of Object.entries(faces)) {
      if (!(await isArabicFamily(family))) continue;
      for (const spec of new Set(specs)) {
        const weight = parseInt(spec, 10);
        const style = spec.endsWith('i') ? 'italic' : 'normal';
        const face = new FontFace(family, `url(${await arabicFileUrl(family, weight, style)}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: arabicRange() });
        document.fonts.add(await face.load().catch(() => {
          throw new Error(`Fontsource has no arabic file for ${family} ${weight} ${style}`);
        }));
        loaded++;
      }
    }
  } catch (error) {
    kitFail(error);
    throw error;
  }
  return loaded;
}

/** The PDF font provider for recipes with Arabic faces: a family with an
 *  arabic subset gets its arabic file when its pages set Arabic letters
 *  (`request.codePoints`), then its latin file, and its latin-ext file for
 *  the letters beyond latin (transliteration: ā ḥ ʿ), each marked with its
 *  unicode-range and its place in the order the screen added them (latin
 *  and latin-ext by loadFonts, then arabic): the arabic file also has a
 *  space and brackets, which the browser takes from latin, the file whose
 *  range holds them, and postext-pdf follows it. Any other family goes to
 *  fontsourceProvider (the "pdf" block). */
async function arabicPdfProvider(family, weight, style, request) {
  if (!(await isArabicFamily(family))) return fontsourceProvider(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 wanted = [...(request?.codePoints ?? [])];
  const id = fontsourceId(family);
  const subsets = !wanted.length || wanted.some(inArabicRange) ? ['arabic', 'latin'] : ['latin'];
  if (meta.subsets.includes('latin-ext') && wanted.some((cp) => /[Ā-˿Ḁ-ỿ]/u.test(String.fromCodePoint(cp)))) {
    subsets.push('latin-ext');
  }
  const at = await fontsourceAt(id);
  return Promise.all(subsets.map(async (subset) => {
    const url = `${at}files/${id}-${subset}-${w}-${s}.woff2`;
    const res = await fetch(url);
    if (!res.ok) throw new Error(`Fontsource file ${url} (${res.status})`);
    const bytes = await decompressWoff2(new Uint8Array(await res.arrayBuffer()));
    return Object.assign(bytes, { unicodeRange: subset === 'arabic' ? arabicRange() : kitRanges()[subset],
      order: ['latin', 'latin-ext', 'greek', 'arabic'].indexOf(subset) });
  }));
}

// ─── Kit · book v1 ── books bound on either edge · postext.dev/cookbook
// A book bound on the right (Arabic, Hebrew or Persian text, vertical
// Chinese, or page.binding 'right') opens from what a Latin reader calls
// the back: page 1 lies alone on the left of the spine, then [3 | 2].

/** showPages for a book bound on either edge. A right-bound book (the
 *  document says so: doc.binding is 'right' for page.binding 'right', for
 *  text that runs right to left and for vertical text, when the binding is
 *  left to 'auto') 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-book')) {
    // The pages keep direction ltr, as in a left-bound book: a canvas takes
    // the direction its element inherits, and under the spread's rtl a run
    // painted for an ltr canvas would end where the engine starts it.
    document.head.insertAdjacentHTML('beforeend', `<style id="pt-kit-book">
      .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 ───────────────────────────────────────────────────────────────────────
```

## 变化

### 印教师用书

答案用`answers`的颜色印在原位：点已经连好，词填进空格，正确的方框涂满，方阵里的词圈了出来。

```diff
-const exercises = { solutions: { placement: 'directive' } };
+const exercises = { edition: 'teacher', solutions: { placement: 'none' } };
```

### 用中文写练习

[中文练习册](https://postext.dev/zh/cookbook/chinese-exercise-book.md)用自己的括号和数字排同样几类练习。

## 常见问题

- **阿拉伯文书标记为'ar'，不要用LANG.** 食谱的版本是en和es，但阿拉伯文示例在两个版本里都是阿拉伯文：`locale: LANG`会让它从左向右排、左装订、页码印成1 2 3，并把图标注为Figure或Figura。postext 1.30起，这个标记也是文字成形所用的语言（测量、绘制和嵌入都按它进行），所以标记成英文或西班牙文时，Markazi Text这样的字体不画尖角引号（« »）和句点的阿拉伯文字形，断行的位置也随之改变。自己写出标记：'ar'（阿拉伯-印度数字，马什里克惯例），或带地区的'ar-EG'、'ar-SA'；马格里布版本用欧洲数字，写'ar-MA'、'ar-DZ'或'ar-TN'。只引用阿拉伯文的拉丁文页面保留自己的locale。
- **阿拉伯文字体需要通过arabic块加载其arabic文件.** Fontsource把Amiri、Noto Naskh Arabic或Scheherazade New按子集分成多个文件提供，阿拉伯字母在arabic文件里。loadFonts只获取latin（以及latin-ext），所以屏幕上的阿拉伯文来自系统字体，测量不准；fontsourceProvider交给PDF的也是这个latin文件，印出来是空框。列出kit中的arabic块，在loadFonts之后调用loadArabicFonts(FONTS, markdown)，并在FONTS中列出页面用于阿拉伯文的每个字重，再给renderToPdf传fontProvider: arabicPdfProvider。

- 大多数阿拉伯文字体没有✓和✗：判断题的对错写作صح和خطأ，题目要求在方框里做记号。
- 找词方阵用它那些词的字母填满空格，用的是字母的独立形式。挑字母多样的词，否则方阵里会满是ة。

## 致谢

- 食谱: Ignacio Ferro ([@drnachio](https://github.com/drnachio))
- 图片: A school garden in an Arab town: date palms, a fountain, lemon trees, a girl watering plants and a boy carrying a pot of mint.: Generated With Diffusion Models, 原创
- 字体: Noto Naskh Arabic (OFL-1.1), Baloo Bhaijaan 2 (OFL-1.1)
- 代码: MIT · 示例内容: CC-BY-4.0

## 相关食谱

- [No. 161 · 十种文字的写字练习册](https://postext.dev/zh/cookbook/handwriting-workbook.md): 一本入门写字练习册，网站的每种语言各排一版：各国的学校字体写在本国的书写格上，先是范字，再是描的点字，最后是空行。 · 难度 2 (中级) · 练习册与习题, 教科书
- [No. 109 · 印欧洲数字的马格里布版阿拉伯文书](https://postext.dev/zh/cookbook/maghreb-edition-european-digits.md): 为摩洛哥印制的阿拉伯文书中的一章：locale 'ar-MA'保持从右向左和右侧装订，并把引擎生成的每个数字写作1、2、3。 · 难度 1 (基础) · 手册、指南与参考书
- [No. 171 · 中文练习册：学生用书与教师用书](https://postext.dev/zh/cookbook/chinese-exercise-book.md): 一本语文和数学练习册：一、二、分大题，题后带（　）括号，还有田字格和竖式。同一份文本排两次，一本给学生，一本给老师。 · 难度 2 (中级) · 练习册与习题, 教科书