报纸上的日更四格和周日半版

// ═══ Postext Cookbook · Nº 146 · A daily strip and a Sunday half page in the newspaper ═══
// https://postext.dev/en/cookbook/newspaper-daily-strip
// Code: MIT · Text: original (CC BY 4.0) · Pictures: generated with diffusion models
// Fonts: Newsreader, Archivo Narrow, Comic Neue, Bangers and 12 more (OFL) · Needs postext ≥ 1.21.0
//
// Two pages of a newspaper's pull-out comics section: a four-panel daily strip across the head
// of a four-column page, and a Sunday half page with its own panel grid. Both are :::strip blocks
// in the text: the columns flow around them as they flow around a page-wide figure.
import {
  buildDocument, renderPageToCanvas, clearMeasurementCache, registerResourceImage,
} from 'https://esm.sh/postext';
import { renderToPdf, decompressWoff2 } from 'https://esm.sh/postext-pdf';

const LANG = 'zh'; // @lang: the sample's language: 'en' | 'es' | 'ca' | 'zh' | 'ar' | 'ja' | 'pt'
const RECIPE = 'newspaper-daily-strip';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
// #region palette: newsprint, ink and the paper's red
const palette = {
  ink: '#16181b', // text, rules, panel borders and the lettering
  paper: '#f6f3ec', // newsprint
  accent: '#b3261e', // section flags, kickers and the sound effects
  tint: '#e9e4d8', // the advert's box
  rule: '#8f9196', // the column rules
  muted: '#575b61', // bylines and the folio line
};
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: 'ink (defaults)', value: { hex: palette.ink, model: 'hex' } },
];
// #endregion

// #region editions: the newspaper's text, label and lettering faces in each script
const [TEXT, LABEL, LETTERING, SFX] = t({
  en: ['Newsreader', 'Archivo Narrow', 'Comic Neue', 'Bangers'],
  es: ['Newsreader', 'Archivo Narrow', 'Comic Neue', 'Bangers'],
  ca: ['Newsreader', 'Archivo Narrow', 'Comic Neue', 'Bangers'],
  pt: ['Newsreader', 'Archivo Narrow', 'Comic Neue', 'Bangers'],
  zh: ['Noto Serif SC', 'Noto Sans SC', 'ZCOOL KuaiLe', 'ZCOOL QingKe HuangYou'],
  ja: ['Noto Serif JP', 'Noto Sans JP', 'Zen Antique', 'Dela Gothic One'],
  ar: ['Noto Naskh Arabic', 'Noto Kufi Arabic', 'Playpen Sans Arabic', 'Lalezar'],
});
const CJK = LANG === 'zh' || LANG === 'ja';
// Design text aligns to physical sides: an Arabic page starts on the right.
const [START, END] = LANG === 'ar' ? ['right', 'left'] : ['left', 'right'];
// #endregion
const MARGIN = { top: 31, bottom: 14, side: 12 }; // mm: a newspaper's narrow, even margins
const GUTTER = 4; // mm: four columns of 48.5 mm on the 206 mm text width
const LEAD = CJK ? 15 : LANG === 'ar' ? 16 : 12.2; // pt: the baseline grid
const at = (to, edge, x = 0, y = 0) => ({ anchor: { to, edge }, offset: { x: mm(x), y: mm(y) } });
const label = (size, look = {}) => ({ fontFamily: LABEL, fontSize: pt(size), fontWeight: 700,
  color: col('ink'), ...look });

// #region answer: a page-wide daily strip and a Sunday half page, set in the columns
// In the Markdown each strip is a fenced block, where the paper wants it:
//   :::strip{split="55 / * [40 | *]" height=210mm}   the Sunday half page, on the cover
//   :::strip{split="* | * | * | *" span=page placement=bottom}   the daily: four square panels
// On the one-column cover the Sunday strip is set in the text, 210 mm deep. Inside, the daily
// floats to the foot of the page, as wide as its four columns, and the columns of the article
// end level above it. A strip never splits; one that does not fit moves to the next page.
// The panels, gutters and balloons come from the comics settings, as on a comic page.
const comics = {
  gutter: { horizontal: mm(3), vertical: mm(3) },
  panel: { borderWidth: pt(0.75), borderColor: col('ink'), background: col('paper') },
  lettering: { fontFamily: LETTERING, fontSize: pt(7.5), color: col('ink'), inset: mm(1) },
  balloonStyles: [
    { id: 'speech', fill: col('paper'), stroke: col('ink') },
    { id: 'whisper', fill: col('paper'), stroke: col('ink') },
    { id: 'shout', fill: col('paper'), stroke: col('ink') },
    { id: 'caption', fill: col('accent'), stroke: col('accent'), color: col('paper'),
      fontFamily: LABEL, bold: true },
    { id: 'sfx', fontFamily: SFX, color: col('accent'), haloColor: col('paper') },
  ],
};
const layout = { layoutType: 'multiple', columnCount: 4, gutterWidth: mm(GUTTER),
  columnRule: { enabled: true, color: col('rule'), lineWidth: pt(0.4) } };
// #endregion

// The section flag heads every page of the pull-out: its name over a 3 pt bar, the folio line
// above it. It lives in the header, so the cover's strip starts right under it, and a float
// written after an opener can still take that page's foot (gotcha: top-float-next-page).
const WIDTH = 230 - 2 * MARGIN.side; // mm: the text width
const SECTION = t({ en: 'Funnies', es: 'Tebeos', ca: 'Còmics', zh: '漫画版', ar: 'صفحة الكوميكس',
  ja: '漫画面', pt: 'Quadrinhos' });
const across = (y) => ({ ...at('page', 'top-left', MARGIN.side, y), size: { width: mm(WIDTH) } });
const header = { elements: [
  { kind: 'text', id: 'folio', content: '{pageNumber}  ·  {title}  ·  {publishDate}',
    ...label(8, { color: col('muted') }), align: START, placement: across(8) },
  { kind: 'text', id: 'flag', content: SECTION, ...label(30, { color: col('accent') }),
    lineHeight: 1, align: START, placement: across(12.5) },
  { kind: 'text', id: 'tag', content: '{subtitle}', ...label(9, { color: col('muted') }),
    align: END, placement: across(19.5) },
  { kind: 'rule', id: 'bar', thickness: pt(3), color: col('ink'), placement: across(24.5) },
] };

const config = () => ({ // a factory: the engine caches resolved configs per object
  locale: t({ en: 'en-gb', es: 'es', ca: 'ca', ja: 'ja', zh: 'zh-Hans', ar: 'ar',
    pt: 'pt-BR' }),
  colorPalette, comics,
  layout: { layoutType: 'single' }, // the cover; the inside page is a section in four columns
  // The pull-out is a tabloid sheet folded once more: 230 × 310 mm.
  page: { sizePreset: 'custom', width: mm(230), height: mm(310), dpi: 150,
    backgroundColor: col('paper'),
    margins: { top: mm(MARGIN.top), bottom: mm(MARGIN.bottom), left: mm(MARGIN.side),
      right: mm(MARGIN.side) } },
  bodyText: { fontFamily: TEXT, fontSize: pt(CJK ? 8.5 : 9), lineHeight: pt(LEAD),
    color: col('ink'), boldColor: col('ink'), italicColor: col('ink'), referenceColor: col('ink'),
    textAlign: 'justify', firstLineIndent: CJK ? em(1) : mm(3), indentAfterHeading: false,
    hyphenation: { enabled: true }, optimalLineBreaking: true,
    avoidWidows: true, avoidOrphans: true, avoidRunts: true },
  headings: { fontFamily: TEXT, fontWeight: 700, color: col('ink'),
    levels: [
      // Restated: any headings object drops the H1 break (gotcha: headings-drop-h1-break).
      { level: 1, span: 'page', fontSize: pt(28), lineHeight: pt(32), marginTop: pt(0),
        marginBottom: pt(LEAD * 0.5), breakBefore: { enabled: true, parity: 'any' } },
      { level: 2, fontFamily: LABEL, fontSize: pt(12), lineHeight: pt(LEAD),
        marginTop: pt(LEAD), marginBottom: pt(0) },
      { level: 3, fontFamily: LABEL, fontSize: pt(9.5), lineHeight: pt(LEAD),
        marginTop: pt(LEAD), marginBottom: pt(0) },
    ] },
  // An H1 opens the inside page, and its style turns that page into four columns.
  headingStyles: [{ id: 'inside', layout }],
  paragraphStyles: [
    { id: 'contents', fontFamily: LABEL, fontSize: pt(14), lineHeight: pt(LEAD * 1.5),
      textAlign: 'left', firstLineIndent: pt(0), spaceBetween: pt(LEAD * 0.5) },
    { id: 'byline', ...label(8.5, { color: col('muted') }), textAlign: 'left',
      firstLineIndent: pt(0), marginBottom: pt(LEAD * 0.5) },
    { id: 'flush', firstLineIndent: pt(0), textAlign: 'left' }, // letters, ragged
    { id: 'imprint', ...label(7, { color: col('muted'), fontWeight: 400 }), textAlign: 'left',
      firstLineIndent: pt(0), marginTop: pt(LEAD) },
  ],
  calloutStyles: [{ id: 'ad', background: col('tint'), keepTogether: true,
    stripe: { enabled: true, side: 'top', width: pt(2.5), color: col('accent') },
    padding: { top: mm(3), right: mm(4), bottom: mm(4), left: mm(4) },
    titleStyle: { ...label(7.5, { color: col('muted') }), gap: mm(2) }, // "Advertisement"
    body: { fontFamily: LABEL, fontSize: pt(11), lineHeight: pt(LEAD * 1.2), textAlign: 'left',
      firstLineIndent: pt(0), paragraphSpacing: true } }],
  header,
  footer: { elements: [] },
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
Markdown样例 · 105行 · content.zh.md
title: "科灵顿快报"
subtitle: "皮普和奥托十周年 · 浮冰来信"
publishDate: "2026年10月17日 星期六"
---

:::strip{split="55 / * [40 | *]" height=210mm}
::panel{art=po5}
caption{at=top-start}: 皮普和奥托 · 浮冰上的星期天
pip: 奥托，你开着面包店，干吗还钓鱼？
otto: 面包从来不挣扎。
::panel{art=po6}
pip: 看！晚饭！
fish{whisper}: 把我放回去。
::panel{art=po7}
sfx{at="62% 72%"}: 扑通！
pip{shout}: 哈！正好是你的尺码！
otto: 嗯。还差不多是新的。
:::

:::paragraphs{style="contents"}
**本期内页：**皮普和奥托十周年。伊内丝·巴洛谈十年来的羊角面包、鱼和一个领结。

**浮冰来信：**读者提问，奥托作答。都在第2页。

**下周日：**奥托学滑冰。
:::

# 浮冰上的十个冬天 {style="inside"}

:::strip{split="* | * | * | *" span=page placement=bottom}
::panel{art=po1}
pip: 早上好，奥托！来一个羊角面包。
otto: 马上就好！
::panel{art=po2}
otto: 刚出炉的！
::panel{art=po3}
pip: 有没有小一点的？
::panel{art=po4}
sfx: 啊呜
otto: 给。小一点了。
:::

:::paragraphs{style="byline"}
本报文化记者 露丝·奥卡福
:::

伊内丝·巴洛每个工作日的早上，都坐在盐沼巷家中的厨房餐桌前画一只企鹅和一头海象，一画就是十年。《皮普和奥托》2016年10月17日首次登上《科灵顿快报》，挤在填字游戏下面。如今它在十一家报纸上连载，有六种语言，仍然只用四个方格。

“规矩是笑点必须落在第四格，早一格都不行，”巴洛说，“要是奥托在第二格就逗乐了，这一天的漫画就白画了。”皮普个子小，有礼貌，总是饿。奥托在一块浮冰上开面包店，系着领结上班，从来没有正面回答过一个问题。读者给他们俩都写信，大部分是写给奥托的。

巴洛是在哈罗路父母的面包店楼上长大的，羊角面包就是这么来的。企鹅来得晚一些，出自祖母从开普敦寄来的一张明信片。“我九岁的时候在订货本背面画了皮普，那时他就围着围巾了。奥托又花了我二十年。”

2016年夏天，她把最早的六组漫画寄给快报，附信只有一行。当时的漫画编辑马丁·弗莱让它试登一个月。这个试用期到现在还没结束。已经退休的弗莱，至今仍提前一天收到邮寄来的漫画。“哪个笑话不够好，他会告诉我，”巴洛说，“他通常是对的。”

每周一，她先在A4纸上用铅笔画五张草稿，每张四格。到周三，线稿上墨、上色完成。画稿送到报社时上面一个字也没有；文字另外寄，是一份简短的脚本：谁说话，在第几格，说什么。拟声词也单独占一行。

这个习惯始于2019年的法文版。“一组漫画用手写两遍字，就是一个星期的活儿，”她说，“现在每家报纸用自己的语言排字，再围着文字画对话框。”西班牙的报纸收到的是“¡Recién salido del horno!”；日文版把对话框排成竖行，和阿拉伯文版一样从右往左读格子。画面从来不改。

星期天的漫画是四格规矩的例外。它占半个版面，是彩色的，巴洛把它当成短篇故事来画：三格，笑话来得慢一些，通常还有一条鱼。本周的那一篇登在封面上。

这对搭档接下来干什么？“奥托要学滑冰，”巴洛说，“他不会喜欢的。”

## 皮普和奥托的数字

:::paragraphs{style="flush"}
2016年10月以来，日更漫画**2516**组。星期天半版**520**期。**11**家报纸，**6**种语言。**1**个领结。
:::

## 浮冰来信

:::paragraphs{style="flush"}
**亲爱的奥托：**我儿子想知道，海象为什么需要领结。——阿伯茨福德 格蕾丝
:::

**奥托答：**上班不打扮的面包师，烤出来的面包也没精神。

:::paragraphs{style="flush"}
**亲爱的皮普：**你吃完过一整个羊角面包吗？——河滨区 托马什（8岁）
:::

**皮普答：**吃完过一次。花了两天，奥托还收了我两回钱。

:::paragraphs{style="flush"}
**亲爱的奥托：**浮冰上的面包店真的存在吗？我想去看看。——哈罗 D.基恩太太
:::

**奥托答：**它会漂来漂去。请带件外套。

:::paragraphs{style="flush"}
**亲爱的伊内丝·巴洛：**皮普会长大吗？——布鲁克巷 萨姆
:::

**伊内丝·巴洛答：**他每个冬天都长一点儿，只是自己没发觉。

:::paragraphs{style="flush"}
来信请寄科灵顿桥街12号快报社皮普和奥托收，也可发电子邮件。来信可能经过删节。
:::

:::callout{type="ad" title="广告"}
**《浮冰上的十个冬天》**皮普和奥托头十年的全部星期天漫画，合成一本书。240页，全彩，快报商店及各大书店有售，18英镑。
:::

:::paragraphs{style="imprint"}
正文用思源宋体和思源黑体排版；对白用站酷快乐体和站酷庆科黄油体（SIL OFL）。画面由扩散模型生成。
:::
`; // content.<lang>.md, inlined by the Cookbook

// #region art: the seven pictures: safe area, speakers' anchors and avoid zones
// From the art manifest; fractions of each picture, the same in every language.
const face = (x, y, width, height) => ({ x, y, width, height });
const ART = {
  po1: { width: 1024, height: 1024, safeArea: face(0.11, 0.22, 0.71, 0.45),
    anchors: [{ id: 'pip', x: 0.27, y: 0.58, face: face(0.11, 0.44, 0.22, 0.2) },
      { id: 'otto', x: 0.67, y: 0.37, face: face(0.56, 0.23, 0.24, 0.22) }] },
  po2: { width: 1024, height: 1024, safeArea: face(0.07, 0.14, 0.79, 0.56),
    anchors: [{ id: 'pip', x: 0.23, y: 0.62, face: face(0.07, 0.5, 0.22, 0.18) },
      { id: 'otto', x: 0.75, y: 0.31, face: face(0.52, 0.14, 0.33, 0.22) }],
    avoid: [face(0.28, 0.17, 0.38, 0.39)] },
  po3: { width: 1024, height: 1024, safeArea: face(0.03, 0.18, 0.72, 0.56),
    anchors: [{ id: 'pip', x: 0.275, y: 0.36, face: face(0.1, 0.19, 0.25, 0.21) }],
    avoid: [face(0.34, 0.41, 0.64, 0.41)] },
  po4: { width: 1024, height: 1024, safeArea: face(0.07, 0.19, 0.84, 0.53),
    anchors: [{ id: 'pip', x: 0.23, y: 0.61, face: face(0.07, 0.48, 0.22, 0.18) },
      { id: 'otto', x: 0.69, y: 0.36, face: face(0.53, 0.19, 0.39, 0.23) }],
    avoid: [face(0.31, 0.63, 0.05, 0.08), face(0.39, 0.32, 0.29, 0.18)] },
  po5: { width: 1400, height: 600, safeArea: face(0.16, 0.17, 0.6, 0.66),
    anchors: [{ id: 'pip', x: 0.345, y: 0.53, face: face(0.29, 0.4, 0.09, 0.18) },
      { id: 'otto', x: 0.625, y: 0.33, face: face(0.58, 0.17, 0.12, 0.23) }] },
  po6: { width: 1152, height: 1152, safeArea: face(0.3, 0.21, 0.43, 0.35),
    anchors: [{ id: 'pip', x: 0.46, y: 0.39, face: face(0.35, 0.25, 0.2, 0.18) },
      { id: 'fish', x: 0.66, y: 0.46, face: face(0.64, 0.41, 0.07, 0.12) }] },
  po7: { width: 1400, height: 933, safeArea: face(0.07, 0.15, 0.81, 0.65),
    anchors: [{ id: 'pip', x: 0.195, y: 0.64, face: face(0.1, 0.56, 0.15, 0.14) },
      { id: 'otto', x: 0.795, y: 0.35, face: face(0.7, 0.18, 0.18, 0.22) },
      { id: 'sfx', x: 0.62, y: 0.7 }],
    avoid: [face(0.44, 0.3, 0.15, 0.32)] },
};
const ALT = {
  po1: t({ en: 'Pip the penguin waddles into Otto the walrus’s tiny bakery, waving.',
    es: 'Pip, el pingüino, entra saludando en la pequeña panadería de Otto, la morsa.',
    ca: 'En Pip, el pingüí, entra saludant a la petita fleca de l’Otto, la morsa.',
    zh: '企鹅皮普摇摇摆摆走进海象奥托的小面包店，挥着手。',
    ar: 'البطريق بيب يدخل مخبز الفظّ أوتو الصغير وهو يلوّح.',
    ja: 'ペンギンのピップが手を振りながら、セイウチのオットーの小さなパン屋に入ってくる。',
    pt: 'O pinguim Pip entra acenando na padariazinha da morsa Otto.' }),
  po2: t({ en: 'Otto proudly holds up a croissant as big as Pip.',
    es: 'Otto enseña orgulloso un cruasán tan grande como Pip.',
    ca: 'L’Otto ensenya orgullós un croissant tan gran com en Pip.',
    zh: '奥托得意地举起一个和皮普一样大的羊角面包。',
    ar: 'أوتو يرفع بفخر كرواسونًا بحجم بيب.',
    ja: 'オットーが、ピップと同じくらい大きなクロワッサンを得意げに持ち上げる。',
    pt: 'Otto ergue, todo orgulhoso, um croissant do tamanho do Pip.' }),
  po3: t({ en: 'Pip stands on the counter next to the giant croissant, scratching his head.',
    es: 'Pip, de pie en el mostrador junto al cruasán gigante, se rasca la cabeza.',
    ca: 'En Pip, dret al taulell al costat del croissant gegant, es grata el cap.',
    zh: '皮普站在柜台上，挨着巨大的羊角面包挠头。',
    ar: 'بيب واقف على المنضدة بجانب الكرواسون العملاق يحكّ رأسه.',
    ja: 'ピップがカウンターの巨大なクロワッサンの横に立ち、頭をかいている。',
    pt: 'Pip, de pé no balcão ao lado do croissant gigante, coça a cabeça.' }),
  po4: t({ en: 'Otto munches the big half of the croissant; Pip holds a tiny end piece.',
    es: 'Otto se come la mitad grande del cruasán; Pip sostiene una punta diminuta.',
    ca: 'L’Otto es menja la meitat gran del croissant; en Pip aguanta una punta minúscula.',
    zh: '奥托大口吃着大半个羊角面包；皮普手里拿着一小截面包尖。',
    ar: 'أوتو يلتهم النصف الكبير من الكرواسون، وبيب يمسك طرفًا صغيرًا.',
    ja: 'オットーがクロワッサンの大きいほうをほおばり、ピップは小さな端っこを持っている。',
    pt: 'Otto devora a metade grande do croissant; Pip segura uma pontinha.' }),
  po5: t({ en: 'Pip and Otto fish through a hole in an ice floe beside a tiny bakery hut.',
    es: 'Pip y Otto pescan por un agujero en un témpano, junto a una caseta de panadería.',
    ca: 'En Pip i l’Otto pesquen per un forat en un glaç, al costat d’una caseta de fleca.',
    zh: '皮普和奥托在浮冰的冰洞里钓鱼，旁边是一间小面包屋。',
    ar: 'بيب وأوتو يصطادان من ثقب في جليد طافٍ بجانب كوخ مخبز صغير.',
    ja: '流氷の穴でピップとオットーが釣りをしている。そばに小さなパン屋の小屋。',
    pt: 'Pip e Otto pescam num buraco do bloco de gelo, ao lado de uma padariazinha.' }),
  po6: t({ en: 'Pip proudly holds up a tiny, unimpressed fish.',
    es: 'Pip levanta orgulloso un pez diminuto y nada impresionado.',
    ca: 'En Pip aixeca orgullós un peix minúscul i gens impressionat.',
    zh: '皮普得意地举起一条小小的、一脸不屑的鱼。',
    ar: 'بيب يرفع بفخر سمكة صغيرة لا يبدو عليها أي إعجاب.',
    ja: 'ピップが、少しもうれしそうでない小さな魚を得意げに持ち上げる。',
    pt: 'Pip ergue, todo orgulhoso, um peixinho nada impressionado.' }),
  po7: t({ en: 'Otto reels in a soggy boot; Pip has fallen on his back laughing.',
    es: 'Otto saca del agua una bota empapada; Pip se ha caído de espaldas de la risa.',
    ca: 'L’Otto treu de l’aigua una bota xopa; en Pip ha caigut d’esquena de riure.',
    zh: '奥托钓上来一只湿透的靴子；皮普笑得仰面摔倒。',
    ar: 'أوتو يسحب حذاءً مبتلًا، وبيب سقط على ظهره من الضحك.',
    ja: 'オットーがずぶぬれの長靴を釣り上げ、ピップは笑いころげてあおむけに倒れている。',
    pt: 'Otto puxa uma bota encharcada; Pip caiu de costas de tanto rir.' }),
};
// #endregion

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
// Every face of the six editions; each edition loads the latin files of all of them and the
// Chinese, Japanese or Arabic files of its own (gotcha: fonts-first).
const FONTS = {
  Newsreader: ['400', '400i', '700'],
  'Archivo Narrow': ['400', '700'],
  'Comic Neue': ['400', '400i', '700', '700i'],
  Bangers: ['400'],
  'Noto Serif SC': ['400', '700'],
  'Noto Sans SC': ['400', '700'],
  'ZCOOL KuaiLe': ['400'],
  'ZCOOL QingKe HuangYou': ['400'],
  'Noto Serif JP': ['400', '700'],
  'Noto Sans JP': ['400', '700'],
  'Zen Antique': ['400'],
  'Dela Gothic One': ['400'],
  'Noto Naskh Arabic': ['400', '700'],
  'Noto Kufi Arabic': ['400', '700'],
  'Playpen Sans Arabic': ['400', '700'],
  Lalezar: ['400'],
};

// ─── 4 · Build & show ───────────────────────────────────────────────────────
const faces = Object.fromEntries([TEXT, LABEL, LETTERING, SFX].map((f) => [f, FONTS[f]]));
await loadFonts(FONTS, markdown);
await loadCjkFonts(faces, markdown);
await loadArabicFonts(faces, markdown);
await loadComicFonts({ [LETTERING]: FONTS[LETTERING], [SFX]: FONTS[SFX] }, markdown);
const panel = (id, url) => comicPanel(id, url, { ...ART[id], alt: ALT[id] });
const resources = await Promise.all([
  panel('po1', asset('po1.jpg')), panel('po2', asset('po2.jpg')), panel('po3', asset('po3.jpg')),
  panel('po4', asset('po4.jpg')), panel('po5', asset('po5.jpg')), panel('po6', asset('po6.jpg')),
  panel('po7', asset('po7.jpg')),
]);
const doc = await buildWithFonts(() => buildDocument({ markdown, resources }, config()), markdown);
showBook(doc, { title: t({ en: 'A daily strip and a Sunday half page in the newspaper',
  es: 'Una tira diaria y media página dominical en el periódico',
  pt: 'Uma tirinha diária e meia página de domingo no jornal' }) });
offerPdf(() => renderToPdf(doc, { fontProvider: comicPdfProvider, resourceBytes: imageBytes }),
  `${RECIPE}.pdf`);

工具包 · core, fonts, viewer, pdf, images, cjk, arabic, comics：每道食谱都相同 · 722行
// ─── Kit ── helpers shared by every Cookbook recipe · postext.dev/cookbook ─────

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

// ─── Kit · fonts v2 ── the same in every recipe · postext.dev/cookbook
// Postext measures with the loaded faces and caches the widths: load every face
// before the first build, from Fontsource, the files the PDF embeds too.

/** faces = { 'Family Name': ['400', '400i', '700'] }. `text` is the sample:
 *  č ł † α χ also load latin-ext and greek files (kitSubsetsFor). With
 *  `optional`, a face Fontsource does not ship is skipped instead of failing.
 *  Resolves to the number of faces added. */
async function loadFonts(faces, text = '', { optional = false } = {}) {
  kitStatus('Loading fonts…');
  const ranges = {
    latin: 'U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,'
      + 'U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD',
    'latin-ext': 'U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,'
      + 'U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF',
    greek: 'U+0370-03FF',
  };
  const jobs = [];
  let added = 0;
  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 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?.weights.includes(weight) && meta.styles.includes(style))) continue;
      for (const subset of subsets) {
        const url = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${weight}-${style}.woff2`;
        const face = new FontFace(family, `url(${url}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: ranges[subset] });
        jobs.push(face.load().then((ready) => { document.fonts.add(ready); added++; }, () => {
          if (subset === 'latin' && !optional) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
        }));
      }
    }
  }
  await Promise.all(jobs).catch((error) => { kitFail(error); throw error; });
  return added;
}

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

/** Every font string of the layout; `base` marks a block's own face. */
function fontStringsOf(doc) {
  const found = new Map();
  const walk = (node) => {
    if (!node || typeof node !== 'object') return;
    if (Array.isArray(node)) { node.forEach(walk); return; }
    for (const [key, value] of Object.entries(node)) {
      if (typeof value === 'string' && /fontString$/i.test(key)) {
        found.set(value, found.get(value) || key === 'fontString');
      } else if (value && typeof value === 'object') walk(value);
    }
  };
  walk(doc.pages);
  walk(doc.blocks);
  return [...found].map(([font, base]) => ({ font, base }));
}

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

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

/** 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, '-'); }

/** The family's Fontsource metadata (weights, styles, subsets), or null. */
function fontsourceMeta(family) {
  fontsourceMeta.cache ??= new Map();
  const id = fontsourceId(family);
  if (!fontsourceMeta.cache.has(id)) {
    fontsourceMeta.cache.set(id, fetch(`https://api.fontsource.org/v1/fonts/${id}`)
      .then((res) => (res.ok ? res.json() : null), () => null));
  }
  return fontsourceMeta.cache.get(id);
}

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

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

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

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

// ─── Kit · pdf v2 ── the same in every recipe that exports a PDF
/** The Fontsource files the screen used, as TrueType: the nearest weight the
 *  family ships, upright if it has no italic; latin, then what the face's
 *  letters need (kitSubsetsFor). */
async function fontsourceProvider(family, weight, style, request) {
  const id = fontsourceId(family);
  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 && !meta.styles.includes('italic') ? 'normal' : style;
  const text = String.fromCodePoint(...(request?.codePoints ?? []));
  const more = kitSubsetsFor(text, meta);
  const files = await Promise.all(['latin', ...more].map(async (subset) => {
    const res = await fetch(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${w}-${s}.woff2`);
    if (!res.ok) throw new Error(`Fontsource has no ${family} ${w} ${s} ${subset}`);
    return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
  }));
  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 v1 ── recipes with pictures · postext.dev/cookbook
/** Registers a photo or PNG for the canvas and keeps its bytes for the PDF.
 *  fetch → ImageBitmap never taints the canvas (a plain cross-origin <img> would). */
async function loadImage(fileId, url) {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`Image not found (${res.status}): ${url}`);
  const bytes = new Uint8Array(await res.arrayBuffer());
  registerResourceImage(fileId, await createImageBitmap(new Blob([bytes])));
  (loadImage.bytes ??= new Map()).set(fileId, bytes);
}

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

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

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

// ─── Kit · cjk v1 ── 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 = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/${weight}${style === 'italic' ? '-italic' : ''}.css`;
  if (!cjkSlices.cache.has(css)) {
    cjkSlices.cache.set(css, fetch(css)
      .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], css).href, range, ranges };
      }).reverse()));
  }
  return cjkSlices.cache.get(css);
}

/** The file of `slices` that holds code point `cp`, if any. */
function cjkSliceFor(slices, cp) {
  return slices.find((slice) => slice.ranges.some(([lo, hi]) => cp >= lo && cp <= hi));
}

/** 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 buildWithFonts 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 that
 *  hold the characters its pages set (`request.codePoints`); 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.filter((slice) => picked.has(slice)).map(async (slice) => {
    const res = await fetch(slice.url);
    if (!res.ok) throw new Error(`Fontsource file ${slice.url} (${res.status})`);
    return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
  }));
}

/** 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. Latin comes first: postext-pdf draws a character from the first
 *  file that has it, as the browser takes a character both files hold from
 *  latin. 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 = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${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)]);
  return ext ? [latin, ext] : 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 · arabic v1 ── 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. */
function arabicFileUrl(family, weight, style) {
  const id = fontsourceId(family);
  return `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${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 buildWithFonts 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 ${outside.slice(0, 12).join(' ')}`);
    for (const [family, specs] of Object.entries(faces)) {
      if (!(await isArabicFamily(family))) continue;
      for (const spec of new Set(specs)) {
        const weight = parseInt(spec, 10);
        const style = spec.endsWith('i') ? 'italic' : 'normal';
        const face = new FontFace(family, `url(${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). The arabic file comes
 *  first: it also holds the space and the brackets, so a line of Arabic is
 *  shaped as one run and not cut at every space. 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 urls = [];
  if (!wanted.length || wanted.some(inArabicRange)) urls.push(arabicFileUrl(family, w, s));
  urls.push(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-${w}-${s}.woff2`);
  if (meta.subsets.includes('latin-ext') && wanted.some((cp) => /[Ā-˿Ḁ-ỿ]/u.test(String.fromCodePoint(cp)))) {
    urls.push(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-ext-${w}-${s}.woff2`);
  }
  return Promise.all(urls.map(async (url) => {
    const res = await fetch(url);
    if (!res.ok) throw new Error(`Fontsource file ${url} (${res.status})`);
    return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
  }));
}

// ─── Kit · comics v1 ── comic pages · postext.dev/cookbook
// The engine letters a comic in a face per language (defaultComicFont:
// Comic Neue, Zen Antique for Japanese, Noto Sans SC, LXGW WenKai TC,
// Playpen Sans Arabic; defaultComicSfxFont: Bangers, Dela Gothic One,
// ZCOOL KuaiLe, Lalezar) and asks for the bold of a shout or a sound effect
// and the italic of an inner voice. Most of these faces ship one weight and
// no italic: this block declares the file Fontsource does ship for those
// variants, so the canvas measures and paints the letters the PDF embeds
// (the providers snap to the shipped file) and not a bold or a slant the
// browser makes up. It also turns the art manifest into panel resources.

/** faces = { 'Comic Neue': ['400', '700'], Bangers: ['400'] }, as for
 *  loadFonts, after it (and after loadCjkFonts or loadArabicFonts for the
 *  faces of those scripts); the whole FONTS object may be passed. List in
 *  FONTS only what Fontsource ships (Bangers: ['400']): loadFonts fails on
 *  the rest. For each family, the regular, bold, italic and bold italic it
 *  lacks are declared with its nearest file (the regular for the bold, the
 *  upright for the italic) and loaded for `text`. A CJK face needs the cjk
 *  block; an Arabic face setting Arabic, the arabic block. Resolves to the
 *  number of variants added. */
async function loadComicFonts(faces, text = '') {
  kitStatus('Loading fonts…');
  let added = 0;
  try {
    for (const family of Object.keys(faces)) {
      const meta = await fontsourceMeta(family);
      if (!meta) throw new Error(`api.fontsource.org did not describe ${family}: reload to try again`);
      const weights = meta.weights?.length ? meta.weights : [400, 700];
      const styles = meta.styles?.length ? meta.styles : ['normal'];
      for (const [weight, style] of [[400, 'normal'], [700, 'normal'], [400, 'italic'], [700, 'italic']]) {
        if ((weights.includes(weight) && styles.includes(style)) || hasFace(family, weight, style)) continue;
        const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
        const s = style === 'italic' && styles.includes('italic') ? 'italic' : 'normal';
        for (const { url, range } of await comicFaceFiles(family, w, s, meta, text)) {
          document.fonts.add(new FontFace(family, `url(${url}) format('woff2')`,
            { weight: String(weight), style, unicodeRange: range }));
        }
        await document.fonts.load(`${style === 'italic' ? 'italic ' : ''}${weight} 16px "${family}"`, text || 'A');
        added++;
      }
    }
  } catch (error) {
    kitFail(error);
    throw error;
  }
  return added;
}

/** The files of a shipped face ({ url, range }): a CJK face's slices (the
 *  cjk block reads them from its stylesheet), else latin, the latin-ext
 *  and greek files `text` needs, and the arabic file when `text` holds
 *  Arabic. */
async function comicFaceFiles(family, weight, style, meta, text) {
  if (meta.subsets?.some((subset) => /^(chinese|japanese|korean)/.test(subset))) {
    if (typeof cjkSlices !== 'function') throw new Error(`${family} is a CJK face: list the cjk kit block`);
    return (await cjkSlices(family, weight, style)).map(({ url, range }) => ({ url, range }));
  }
  const id = fontsourceId(family);
  const file = (subset) => `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${weight}-${style}.woff2`;
  const files = ['latin', ...kitSubsetsFor(text, meta)].map((subset) => ({ url: file(subset), range: comicRange(subset) }));
  if (meta.subsets?.includes('arabic') && /\p{Script=Arabic}/u.test(text)) {
    if (typeof arabicRange !== 'function') throw new Error(`${family} sets Arabic: list the arabic kit block`);
    files.unshift({ url: file('arabic'), range: arabicRange() });
  }
  return files;
}

/** The unicode-range loadFonts gives a Fontsource file. A function, not a
 *  const: the kit is inlined after the recipe's top-level awaits. */
function comicRange(subset) {
  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',
  }[subset];
}

/** The PDF font provider of a comic in any script: a CJK face goes to
 *  cjkPdfProvider, an Arabic face to arabicPdfProvider, any other to
 *  fontsourceProvider (the "pdf" block). Each embeds the shipped weight
 *  and style nearest to the one asked for, the file loadComicFonts
 *  declared for the canvas. */
async function comicPdfProvider(family, weight, style, request) {
  const subsets = (await fontsourceMeta(family))?.subsets ?? [];
  if (subsets.some((subset) => /^(chinese|japanese|korean)/.test(subset))) {
    if (typeof cjkPdfProvider !== 'function') throw new Error(`${family} is a CJK face: list the cjk kit block`);
    return cjkPdfProvider(family, weight, style, request);
  }
  if (subsets.includes('arabic') && typeof arabicPdfProvider === 'function') {
    return arabicPdfProvider(family, weight, style, request);
  }
  return fontsourceProvider(family, weight, style, request);
}

/** A panel picture as a resource for art= (and pop=): loads `url`
 *  (write asset('lh-arrive.jpg') in the call, so the lint checks the file)
 *  and declares it with `meta`, its entry in the art manifest:
 *  { width, height, alt, safeArea, anchors, avoid }. The safe area is what
 *  every crop keeps, the anchors the speakers' mouths, heads and faces,
 *  the avoid zones what no balloon covers; all in fractions of the picture,
 *  the same in every language. Without width and height, the picture's own
 *  size. Needs the images block. Resolves to the resource. */
async function comicPanel(id, url, meta = {}) {
  const fileId = decodeURIComponent(url.split('/').pop());
  await loadImage(fileId, url);
  let { width, height } = meta;
  if (!width || !height) {
    const bitmap = await createImageBitmap(new Blob([imageBytes(fileId)]));
    ({ width, height } = bitmap);
    bitmap.close();
  }
  return {
    id, typeId: meta.typeId ?? 'figure', kind: 'bitmap', createdAt: 0, updatedAt: 0,
    bitmap: { fileId, format: /\.png$/i.test(fileId) ? 'png' : 'jpeg', width, height },
    ...(meta.alt && { altText: meta.alt }),
    ...(meta.safeArea && { safeArea: meta.safeArea }),
    ...(meta.anchors?.length && { anchors: meta.anchors }),
    ...(meta.avoid?.length && { avoid: meta.avoid }),
  };
}

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