# 前付けはローマ数字、本文は1ページから

> 表紙と前付けは番号なしの見出しで、小文字のローマ数字で数えます。:::numberingで、小説が始まる奇数ページから数え直して1にします。

- HTML版: https://postext.dev/ja/cookbook/front-matter-roman-to-arabic
- レシピ No. 006 · 本の構成 · 難易度 3 (上級) · 出力: Canvas, PDF
- ジャンル: 小説・戯曲・文芸
- 必要なもの postext ≥ 1.4.1, postext-pdf ≥ 1.4.1 · テスト環境 1.8.3, postext-pdf 1.8.3 ／テスト日 2026-09-28
- ページ: [i](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p01.webp?v=f1cde812), [iii](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p03.webp?v=f1cde812), [iv](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p04.webp?v=f1cde812), [v](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p05.webp?v=f1cde812), [vi](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p06.webp?v=f1cde812), [vii](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p07.webp?v=f1cde812), [viii](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p08.webp?v=f1cde812), [ix](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p09.webp?v=f1cde812), [x](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p10.webp?v=f1cde812), [1](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p11.webp?v=f1cde812), [3](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p13.webp?v=f1cde812), [4](https://postext.dev/cookbook/front-matter-roman-to-arabic/en/p14.webp?v=f1cde812)
- PDF: https://postext.dev/cookbook/front-matter-roman-to-arabic/en/front-matter-roman-to-arabic.pdf?v=f1cde812
- Sandboxで開く: https://postext.dev/ja/sandbox#recipe=front-matter-roman-to-arabic&lang=en (.postext: https://postext.dev/cookbook/front-matter-roman-to-arabic/en/front-matter-roman-to-arabic.postext)
- 最終更新: 2026-09-28
- 他の言語: [en](https://postext.dev/en/cookbook/front-matter-roman-to-arabic.md), [es](https://postext.dev/es/cookbook/front-matter-roman-to-arabic.md), [ca](https://postext.dev/ca/cookbook/front-matter-roman-to-arabic.md), [zh](https://postext.dev/zh/cookbook/front-matter-roman-to-arabic.md), [ar](https://postext.dev/ar/cookbook/front-matter-roman-to-arabic.md)

## かんたんな説明

『フランケンシュタイン』のポケット版の冒頭ページです。物語の前のページをi、ii、iiiと数え、物語が始まるページで1に戻して数える方法を示します。

## できあがり

ポケット版の古典として組んだ『フランケンシュタイン』の最初の丁です。判型は129 × 198 mm。モンブランに落ちる稲妻を描いた表紙（裏は白）、前扉、氷に閉じこめられたウォルトンの船を描いて本扉と向かい合う口絵、本扉の裏の下部に置いた権利表示、ミルトンのエピグラフの上に置いたゴドウィンへの献辞、目次、そして1818年の序文が続きます。この10ページはiからxまで数えますが、番号を刷るのは目次と序文だけです。Letter Iはオーロラの下、右ページで小説を始め、そのノンブル1は向かいのページのxと同じ位置にあります。手紙はウォルトンの署名まで続きます。目次で序文の横に付くixと、手紙の横に付く1は、組み上がったページから取ったものです。PDFビューアーもページに同じラベルを付けます。表紙、口絵、オーロラは拡散モデルで生成した絵で、JPEGのビットマップとして読み込みます。出版社のマークと氷の結晶はコードで描いています。

**このレシピが答える問い:**

- 前付けをi、ii、iiiと数え、小説が始まる奇数ページで1から数え直すには？
- 表紙、小扉、扉、奥付を作るには？
- 自動で更新される目次（リーダー、ノンブル、著者名、部の行）を追加するには？
- 意図的に白ページを入れたり、節を新しい見開きから始めたりするには？
- エピグラフ、献辞、署名、大きな引用符の付いたプルクオートを組むには？

## 手短な答え

```js
// script.js, 行 61–83
// The page counter starts in lower-case roman: the cover is page i. After the Preface, two
// directives in the Markdown count again from 1 on the next recto:
//   :::pagebreak{parity="odd"}
//   :::numbering{format="decimal" startAt=1}
// :::numbering takes effect on the next page that starts (gotcha: numbering-next-page). Level 1
// breaks to 'odd', so here the pagebreak changes nothing; it finds the recto when a level breaks
// with parity 'any' or not at all. Never with 'always-odd': the blank pages would stack up.
const pageNumbering = { format: 'lower-roman', startAt: 1 }; // startAt spelled out: cover = i
// One folio design, centred under the text block. {pageNumber} prints the page's own label,
// so the same design sets "x" in the front matter and "1" on the first page of the novel.
const folio = (pages) => text(`folio-${pages}`, '{pageNumber}', 'Playfair Display SC', 8.5,
  at('top', 0, 9), { letterSpacing: pt(0.8), pages }); // lower case sets as small capitals
// The front matter is a heading style, unnumbered and left out of the contents (a heading
// can opt back in with {toc="true"}). It prints no running heads and puts a folio on every
// page of the section. Parity 'any', because the contents fall on a verso.
const front = {
  id: 'front', numbered: false, toc: false, breakBefore: { enabled: true, parity: 'any' },
  header: { elements: [] }, footer: { elements: [folio('all')] }, ...frontLook,
};
// The novel keeps the document's furniture: heads on its body pages, the folio on openers.
const footer = { elements: [folio('opener')] };
// Hook-up in config(): page: { pageNumbering }, headingStyles: [front] and footer at the top
// level. frontLook, set above, is the look of the prelims' openers.
```

## 材料

**学べること**

- [ローマ数字の前付け](https://postext.dev/ja/docs/document-format.md#numbering): 前付けのノンブルをローマ数字にし、第1章で1から振り直します。PDFのページラベルもそれに合わせます。
- [目次](https://postext.dev/ja/docs/configuration.md#目次): 見出しから作る:::tocです。点線のリーダー、印刷どおりのページラベル、著者名の行、色付きの部の行、クリックできるPDFの項目を持ちます。
- [節ごとの柱](https://postext.dev/ja/docs/configuration.md#見出しスタイル): 見出しスタイルが独自のヘッダーとフッターを持つので、前付け、各節、辞書の見出し文字ごとに柱やノンブルを変えられます。

**ほかに使うもの**

- [表紙、扉、奥付](https://postext.dev/ja/docs/configuration.md#見出しスタイル)
- [改ページと改段](https://postext.dev/ja/docs/document-format.md#pagebreak)
- [見出しスタイル](https://postext.dev/ja/docs/configuration.md#見出しスタイル)
- [番号のない章](https://postext.dev/ja/docs/configuration.md#見出しスタイル)
- [節ごとのページ構成](https://postext.dev/ja/docs/configuration.md#見出しスタイル)
- [ページデザインの画像](https://postext.dev/ja/docs/configuration.md#画像要素)
- [奇数ページから始まる章](https://postext.dev/ja/docs/configuration.md#前で改ページ)
- [段落スタイル](https://postext.dev/ja/docs/configuration.md#段落スタイル)
- [デザインした章扉](https://postext.dev/ja/docs/configuration.md#幅と詳細デザイン)
- [見出しの属性](https://postext.dev/ja/docs/document-format.md#見出しの属性)
- [文書のメタデータ](https://postext.dev/ja/docs/document-format.md#フロントマター)
- [柱とノンブル](https://postext.dev/ja/docs/configuration.md#柱とノンブル)
- [ページの役割ごとの柱](https://postext.dev/ja/docs/configuration.md#テキスト要素)
- [見開きの余白](https://postext.dev/ja/docs/configuration.md#見開きの余白)
- [PDFの書き出し](https://postext.dev/ja/docs/configuration.md#pdfの生成)
- [PDFのしおり](https://postext.dev/ja/docs/configuration.md#pdf生成設定)
- [リソースとしての図と表](https://postext.dev/ja/docs/document-format.md#リソース)
- [段抜きの章見出し帯](https://postext.dev/ja/docs/configuration.md#幅と詳細デザイン)
- [用紙の色](https://postext.dev/ja/docs/configuration.md#ページ)
- [PDFに埋め込むフォント](https://postext.dev/ja/docs/configuration.md#なぜフォントプロバイダーが必要か)

**設定の一覧**

- [`bodyText`](https://postext.dev/ja/docs/configuration.md#本文), [`colorPalette`](https://postext.dev/ja/docs/configuration.md#カラーパレット), [`footer`](https://postext.dev/ja/docs/configuration.md#柱とノンブル), [`header`](https://postext.dev/ja/docs/configuration.md#柱とノンブル), [`headingStyles`](https://postext.dev/ja/docs/configuration.md#見出しスタイル), [`headings`](https://postext.dev/ja/docs/configuration.md#見出し), [`layout`](https://postext.dev/ja/docs/configuration.md#レイアウト), [`locale`](https://postext.dev/ja/docs/configuration.md#ハイフネーション), [`page`](https://postext.dev/ja/docs/configuration.md#ページ), [`paragraphStyles`](https://postext.dev/ja/docs/configuration.md#段落スタイル), [`toc`](https://postext.dev/ja/docs/configuration.md#目次)

**API**

- [`buildDocument`](https://postext.dev/ja/docs/configuration.md#文書のビルド), [`clearMeasurementCache`](https://postext.dev/ja/docs/configuration.md#計測キャッシュ), [`decompressWoff2`](https://postext.dev/ja/docs/configuration.md#ブラウザー向けフォントプロバイダーfontsource--woff2), [`registerResourceImage`](https://postext.dev/ja/docs/architecture.md#apiの概要), [`renderPageToCanvas`](https://postext.dev/ja/docs/configuration.md#ページをビットマップに描画する), [`renderToPdf`](https://postext.dev/ja/docs/configuration.md#pdfの生成)

**書体**

- Fanwood Text (OFL-1.1), Playfair Display SC (OFL-1.1), Cinzel (OFL-1.1)

## 作り方

### 1 · どの丁もデザインを持つ見出し

```js
// script.js, 行 87–154
// Each leaf is a heading, so it opens its page, gets a PDF bookmark and takes a design. The
// leaves are unnumbered, left out of the contents and print no heads or folio (blind folios).
// Parity 'any', or each would inherit level 1's odd break (gotcha: style-inherits-break).
const blind = { numbered: false, toc: false, breakBefore: { enabled: true, parity: 'any' },
  header: { elements: [] }, footer: { elements: [] } };
const PLATE_H = 126; // mm: the frontispiece, as wide as the text block; its caption hangs below
// mm from the trim: the imprint's eleven lines end on the text block's last baseline.
const IMPRINT_TOP = 116.5; // re-tune it whenever the imprint changes
const leaves = [
  // i: bled to the trim. Type below the text block's foot would drop the heading's reserve.
  { id: 'cover', ...blind, advancedDesign: design([
    image('cover', at('top-left', 0, 0, { width: 'fill', to: 'bleed' })),
    label('author', '{author}', 9, onPage(22), 'bone', 2.6),
    text('title', '{title}', 'Fanwood Text', 56, onPage(31), { color: col('bone'), lineHeight: 1 }),
    text('subtitle', '{subtitle}', 'Fanwood Text', 13, onPage(53), { ...on('ice'), italic: true }),
    label('series', '{attr.publisher}', 7, onPage(168), 'ice', 2),
  ]) },
  // iii: the half title waits for a recto, so the back of the cover, ii, is left blank.
  { id: 'half', ...blind, breakBefore: { enabled: true, parity: 'odd' }, advancedDesign: design([
    text('title', '{title}', 'Playfair Display SC', 17, at('top', 0, 34), { letterSpacing: pt(3) }),
    image('crystal', at('top', 0, 45, { width: 6 })),
  ]) },
  { id: 'plate', ...blind, advancedDesign: design([ // iv: faces the title page
    image('plate', at('top-left', 0, 0, { width: 'fill' })),
    text('caption', '{attr.caption}', 'Fanwood Text', 8.8,
      at('top', 0, PLATE_H + 5, { width: 80 }), { italic: true, lineHeight: 1.3 }),
    label('source', '{attr.source}', 7.5, at('top', 0, PLATE_H + 16), 'muted', 1.3),
  ]) },
  { id: 'title', ...blind, advancedDesign: design([ // v: four frontmatter fields, one attribute
    // {publishDate} prints because the year is quoted (gotcha: quote-frontmatter).
    label('edition', 'The text of {publishDate}', 7.5, at('top', 0, 22), 'accent', 1.8),
    text('title', '{title}', 'Playfair Display SC', 33, at('top', 0, 30),
      { fontWeight: 700, letterSpacing: pt(0.4), lineHeight: 1 }),
    text('subtitle', '{subtitle}', 'Fanwood Text', 14, at('top', 0, 44), { italic: true }),
    { kind: 'rule', id: 'rule', direction: 'horizontal', thickness: pt(0.8), color: col('accent'),
      placement: at('top', 0, 60, { width: 14 }) },
    label('author', '{author}', 10, at('top', 0, 66), 'ink', 2.4),
    image('mark', at('top', 0, 126, { width: 11 })),
    label('publisher', '{attr.publisher}', 7.5, at('top', 0, 140), 'muted', 1.5),
  ]) },
  // vi: the section's margins set the small print low, in a 70 mm measure against the outer
  // margin. With no element the design would print the title (gotcha: invisible-heading).
  { id: 'imprint', ...blind, margins: { top: mm(IMPRINT_TOP), left: mm(TRIM_W - OUTER - 70) },
    advancedDesign: design([{ kind: 'box', id: 'none', style: { backgroundColor: col('paper') },
      placement: { ...at('top-left', 0, 0), size: { width: pt(0.1), height: pt(0.1) } } }]) },
  // vii: dedication and epigraph, under a heading whose only element is an ornament, which
  // also keeps its title from printing (gotcha: invisible-heading).
  { id: 'quiet', ...blind,
    advancedDesign: design([image('crystal', at('top', 0, 24, { width: 6 }))], 34) },
];
// :::paragraphs blocks set the small print, the dedication, the epigraph and Walton's close;
// the dedication and the verse take one paragraph per line, so no line of them can reflow.
const VERSE_IN = 22; // mm: the indent that centres the verse as a block
const SOURCE_IN = 55; // mm: 'Paradise Lost' ends under the end of the longest line of verse
const prelimStyles = [
  // In ink, not muted: a paragraph style has no italic colour, so its italic title would take
  // bodyText.italicColor and print darker than its words (gotcha: style-italic-colour).
  { id: 'small-print', fontSize: pt(7.6), lineHeight: pt(10.4), textAlign: 'left',
    firstLineIndent: pt(0), spaceBetween: pt(5.2) },
  // Small capitals, with the italic lines of the 1818 page, leaded as one inscription.
  { id: 'dedication', fontFamily: 'Playfair Display SC', fontSize: pt(10), lineHeight: pt(15),
    textAlign: 'center', firstLineIndent: pt(0) },
  { id: 'verse', fontSize: pt(10), textAlign: 'left', firstLineIndent: mm(VERSE_IN),
    marginTop: pt(LEAD * 4) }, // on the body's 14 pt leading, which a style inherits
  { id: 'source', fontFamily: 'Cinzel', fontSize: pt(7.5), textAlign: 'left',
    firstLineIndent: mm(SOURCE_IN), marginTop: pt(4), color: col('muted') },
  { id: 'signature', textAlign: 'right', firstLineIndent: pt(0) }, // the letter's close
];
```

見出しはそれ自身のページを開き、PDFのしおりになります。スタイルのデザインが、その丁の文字と絵を配置します。`numbered: false`と`toc: false`を指定すると、これらの丁は章の数えにも目次にも入りません。ヘッダーとフッターを空にすると、印刷の世界で隠しノンブルと呼ぶものになります。本扉は番号を刷りませんがvページであることに変わりはなく、そのため序文がixになります。奇数ページへの改ページを残すのは前扉だけで、それによって表紙の裏が白ページになります。権利表示、献辞、エピグラフ、ウォルトンの結びは`:::paragraphs`ブロックで、抜粋の最後にあるスタイルで組みます。

### 2 · 目次は番号をレイアウトから取る

```js
// script.js, 行 158–167
// Entries take the body's face and ink, and start on the Preface's first baseline, facing it.
const contents = {
  levels: [{ level: 1, fontSize: pt(12), lineHeight: pt(PREFACE.lead) }],
  // The folio's face: "ix" in small capitals, then a plain 1. The leader takes it too.
  pageNumber: { fontFamily: 'Playfair Display SC', fontSize: pt(10), color: col('accent'),
    width: mm(8) },
  leader: { char: '. ', gap: mm(2.5) },
  // A second line from the heading's to="…" attribute: whom each letter is written to.
  subtitle: { enabled: true, attr: 'to', fontSize: pt(9.5), color: col('muted') },
};
```

`:::toc`は、スタイルが許すすべての見出しを、それが置かれたページのラベルとともに並べます（[目次](/ja/docs/configuration#目次)）。目次と序文は`front`スタイルを共有し、このスタイルは`toc: false`を指定しますが、序文は`{toc="true"}`でそれを上書きします。序文もLetter Iも番号なしなので、その項目には章番号が付きません。手紙の項目の2行目は、その`to="…"`属性です。ページ番号はノンブルの書体で組みます。項目は序文の1行目と同じベースラインから始まるので、向かい合う2ページの行がそろいます。

### 3 · 小説はオーロラの下、奇数ページで始まる

```js
// script.js, 行 171–186
const BAND = 104; // mm from the trim to the foot of the drawing, which fades into the paper
// minHeight ends AIR mm below it and the first line takes the next grid line. to: 'bleed' is the
// trim until page.cutLines adds a bleed; 3 mm drop the foot 1.8 mm, still above that line.
const AIR = 2;
const opener = design([
  image('band', at('top-left', 0, 0, { width: 'fill', to: 'bleed' })),
  label('to', '{attr.to}', 7.5, onPage(19), 'ice', 2),
  text('title', '{titleText}', 'Playfair Display SC', 46, onPage(25),
    { color: col('bone'), lineHeight: 1 }),
  text('dateline', '{attr.dateline}', 'Fanwood Text', 10.5, onPage(44),
    { italic: true, color: col('bone') }),
  // minHeight counts from the text block, TOP below the trim. The texts reserve their height,
  // the drawing nothing (gotcha: opener-image-no-reserve), so minHeight sets the first line.
], BAND - TOP + AIR);
// Walton's letters come before Chapter I: they take the novel's opener but no number.
const letter = { id: 'letter', numbered: false };
```

絵はページの天へ裁ち落とし、地に向かって紙に溶け込み、そこから手紙が始まります。Postext 1.4.1では、画像は章扉が確保する高さに数えられません（テキスト、罫、ボックスは、ページに固定していても数えられます）。そのため`minHeight`だけで1行目を絵の下に置けます（[幅と詳細デザイン](/ja/docs/configuration#幅と詳細デザイン)）。肩見出しと日付行は、見出しの`to`属性と`dateline`属性から取ります。Letter Iには`{style="letter"}`も付けます。これは`numbered: false`だけを指定したスタイルです。ウォルトンの手紙はChapter Iより前にあり、章番号を持たないからです。

### 4 · 小説とともに柱が戻る

```js
// script.js, 行 190–202
const HEAD_Y = 12.5; // mm from the trim to the heads' line
const HEAD_GAP = 8; // mm from the outer margin, where the folio hangs, to the words beside it
const head = (id, content, parity, edge, x, extra = {}) => ({ ...label(id, content, 7.5,
  at(edge, x, HEAD_Y, { to: 'page' }), 'muted', 1.4), align: 'left', parity, pages: 'body',
  ...extra }); // pages: 'body' keeps them off the opener
const numeral = { fontFamily: 'Playfair Display SC', fontSize: pt(8.5), fontWeight: 400,
  letterSpacing: pt(0.6), color: col('ink') }; // folios in the folio face, as on the openers
const header = { elements: [
  head('verso-folio', '{pageNumber}', 'even', 'top-left', OUTER, numeral),
  head('verso-title', '{title}', 'even', 'top-left', OUTER + HEAD_GAP),
  head('recto-title', '{chapterTitle}', 'odd', 'top-right', -(OUTER + HEAD_GAP)),
  head('recto-folio', '{pageNumber}', 'odd', 'top-right', -OUTER, numeral),
] };
```

節は、スタイルが置き換えないかぎり文書のヘッダーとフッターを使います。前付けは両方を置き換え、手紙のスタイルは置き換えません。そのため1ページ目から、小説は本文ページにこの柱を刷り、章扉には手短な答えで定義した章扉用のノンブル（ドロップフォリオ）を刷ります。`{pageNumber}`は置かれたページのラベルを刷るので、`folio()`ヘルパーは同じデザインのまま、のどの片側にx、反対側に1を組みます。

### 5 · PDFも同じページ番号を持つ

```js
// script.js, 行 402–409
await loadFonts(FONTS, markdown);
// :::toc lists each heading with the label of the page it lands on; buildDocument lays the
// document out again until those labels stop moving (ix for the Preface, 1 for Letter I).
const doc = await buildWithFonts(() => buildDocument({ markdown, resources }, config()), markdown);
showPages(doc, { title: 'Frankenstein · the opening leaves' });
// The PDF gets /PageLabels from the same labels: a viewer numbers its pages i–x, then 1, 2.
offerPdf(() => renderToPdf(doc, { fontProvider: fontsourceProvider, resourceBytes: imageBytes }),
  `${RECIPE}.pdf`);
```

`buildDocument`は目次のページラベルが変わらなくなるまでレイアウトを繰り返すので、呼び出しは1回で足ります。`renderToPdf`はそのラベルをPDFに書き込みます。ページラベルを読むビューアーでは、ページ番号欄がiからx、続いて1から進み、「1ページへ移動」でLetter Iが開きます。どの見出しも本文をそのまま名前にしたしおりになるので、丁の題名は飾りのないものにしてあります。Cover、Half title、Frontispiece、Title page、Imprint、Dedicationです。

## レシピの全体

レシピのフォルダーから合成した1つのファイルで、サンプルのテキストとレシピ集の共通キットを埋め込んであり、自分でページを組み立てます。動かすには、空のページの`<script type="module">`に入れるか、新しいCodePenのpenのJSパネルに貼り付けます（モジュールとして）。esm.shからpostextを読み込むので、インストールもビルドも要りません。

- レシピのフォルダー: https://github.com/drnachio/postext/tree/main/cookbook/front-matter-roman-to-arabic

### script.js

```js
// ═══ Postext Cookbook · Nº 006 · Front matter: roman folios, then page 1 ═══════════
// https://postext.dev/en/cookbook/front-matter-roman-to-arabic
// Code: MIT · Text: M. & P. B. Shelley, 1818 (PD) · Pictures: diffusion models; marks drawn in code
// Fonts: Fanwood Text, Playfair Display SC, Cinzel (SIL OFL 1.1) · Needs postext ≥ 1.4.1
import {
  buildDocument, renderPageToCanvas, clearMeasurementCache, registerResourceImage,
} from 'https://esm.sh/postext';
import { renderToPdf, decompressWoff2 } from 'https://esm.sh/postext-pdf';

const LANG = 'en'; // @lang: the language of the sample document ('en' | 'es')
const RECIPE = 'front-matter-roman-to-arabic';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
const palette = { // every colour in the config links to one of these
  ink: '#1c1d21', // text: a cold near-black
  accent: '#3d5a70', // steel blue, the one accent on paper: contents folios, the rule, the marks
  muted: '#6a665f', // running heads, sources, the second lines of the contents
  paper: '#fbf8f2', // the page
  night: '#131a24', ice: '#a9c6d6', bone: '#efe9dc', // the drawings' inks, and the type on them
};
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' } })),
  // The engine's defaults link to 'main-color': point it at the accent, so nothing prints blue.
  { id: 'main-color', name: 'accent (defaults)', value: { hex: palette.accent, model: 'hex' } },
];
const TRIM_W = 129, TRIM_H = 198; // mm: a pocket classic
const TOP = 21, BOTTOM = 23, INNER = 17, OUTER = 15; // margins, mm; heads align to OUTER
const MEASURE = TRIM_W - INNER - OUTER; // 97 mm: the text block, and the frontispiece's width
const LEAD = 14; // body leading in pt: 31 lines fill the text block
const PREFACE = { size: 9.8, lead: 13.3 }; // pt: the preface, a size under the novel's 10.5/14

// Design-slot shorthands. at(): a placement from an anchor's edge; edge 'top' centres it.
const wide = (width) => (width === 'fill' ? 'fill' : mm(width));
const at = (edge, x, y, { width, to = 'container' } = {}) => ({ anchor: { to, edge },
  offset: { x: mm(x), y: mm(y) }, ...(width !== undefined && { size: { width: wide(width) } }) });
const onPage = (y) => at('top', 0, y, { to: 'page' }); // centred on the page, y mm from the trim
const on = (id) => ({ color: col(id) }); // a design text's ink
// overflow 'wrap', or a text too wide ends in '…' (gotcha: overflow-ellipsis-default). A number
// lineHeight multiplies the size; never pt() (gotcha: design-lineheight-multiple).
const text = (id, content, font, size, placement, extra = {}) => ({ kind: 'text', id, content,
  fontFamily: font, fontSize: pt(size), color: col('ink'), align: 'center', overflow: 'wrap',
  placement, ...extra });
const label = (id, content, size, placement, ink, tracking) => text(id, content, 'Cinzel', size,
  placement, { fontWeight: 600, letterSpacing: pt(tracking), textTransform: 'uppercase',
    ...on(ink) }); // the label voice: Cinzel capitals, tracked
const image = (id, placement) => ({ kind: 'image', id, resourceId: id, placement });
// A heading's design. minHeight (mm) where the text must start lower than the elements reach.
const design = (elements, minHeight) => ({ enabled: true, slot: { elements },
  ...(minHeight !== undefined && { minHeight: mm(minHeight) }) });
// The prelims' openers: a centred title in small capitals on white space, and the preface's
// text a size smaller than the novel's, on its own leading.
const FRONT_DROP = 46; // mm from the text block's top to the first line of text
const frontLook = {
  advancedDesign: design([text('title', '{titleText}', 'Playfair Display SC', 19,
    at('top', 0, 14), { letterSpacing: pt(1.6) })], FRONT_DROP),
  bodyStyle: { fontSize: pt(PREFACE.size), lineHeight: pt(PREFACE.lead) },
};

// #region answer: roman folios for the front matter and arabic from Letter I, in one design
// The page counter starts in lower-case roman: the cover is page i. After the Preface, two
// directives in the Markdown count again from 1 on the next recto:
//   :::pagebreak{parity="odd"}
//   :::numbering{format="decimal" startAt=1}
// :::numbering takes effect on the next page that starts (gotcha: numbering-next-page). Level 1
// breaks to 'odd', so here the pagebreak changes nothing; it finds the recto when a level breaks
// with parity 'any' or not at all. Never with 'always-odd': the blank pages would stack up.
const pageNumbering = { format: 'lower-roman', startAt: 1 }; // startAt spelled out: cover = i
// One folio design, centred under the text block. {pageNumber} prints the page's own label,
// so the same design sets "x" in the front matter and "1" on the first page of the novel.
const folio = (pages) => text(`folio-${pages}`, '{pageNumber}', 'Playfair Display SC', 8.5,
  at('top', 0, 9), { letterSpacing: pt(0.8), pages }); // lower case sets as small capitals
// The front matter is a heading style, unnumbered and left out of the contents (a heading
// can opt back in with {toc="true"}). It prints no running heads and puts a folio on every
// page of the section. Parity 'any', because the contents fall on a verso.
const front = {
  id: 'front', numbered: false, toc: false, breakBefore: { enabled: true, parity: 'any' },
  header: { elements: [] }, footer: { elements: [folio('all')] }, ...frontLook,
};
// The novel keeps the document's furniture: heads on its body pages, the folio on openers.
const footer = { elements: [folio('opener')] };
// Hook-up in config(): page: { pageNumbering }, headingStyles: [front] and footer at the top
// level. frontLook, set above, is the look of the prelims' openers.
// #endregion

// #region leaves: the cover and the preliminary leaves, headings that print a design only
// Each leaf is a heading, so it opens its page, gets a PDF bookmark and takes a design. The
// leaves are unnumbered, left out of the contents and print no heads or folio (blind folios).
// Parity 'any', or each would inherit level 1's odd break (gotcha: style-inherits-break).
const blind = { numbered: false, toc: false, breakBefore: { enabled: true, parity: 'any' },
  header: { elements: [] }, footer: { elements: [] } };
const PLATE_H = 126; // mm: the frontispiece, as wide as the text block; its caption hangs below
// mm from the trim: the imprint's eleven lines end on the text block's last baseline.
const IMPRINT_TOP = 116.5; // re-tune it whenever the imprint changes
const leaves = [
  // i: bled to the trim. Type below the text block's foot would drop the heading's reserve.
  { id: 'cover', ...blind, advancedDesign: design([
    image('cover', at('top-left', 0, 0, { width: 'fill', to: 'bleed' })),
    label('author', '{author}', 9, onPage(22), 'bone', 2.6),
    text('title', '{title}', 'Fanwood Text', 56, onPage(31), { color: col('bone'), lineHeight: 1 }),
    text('subtitle', '{subtitle}', 'Fanwood Text', 13, onPage(53), { ...on('ice'), italic: true }),
    label('series', '{attr.publisher}', 7, onPage(168), 'ice', 2),
  ]) },
  // iii: the half title waits for a recto, so the back of the cover, ii, is left blank.
  { id: 'half', ...blind, breakBefore: { enabled: true, parity: 'odd' }, advancedDesign: design([
    text('title', '{title}', 'Playfair Display SC', 17, at('top', 0, 34), { letterSpacing: pt(3) }),
    image('crystal', at('top', 0, 45, { width: 6 })),
  ]) },
  { id: 'plate', ...blind, advancedDesign: design([ // iv: faces the title page
    image('plate', at('top-left', 0, 0, { width: 'fill' })),
    text('caption', '{attr.caption}', 'Fanwood Text', 8.8,
      at('top', 0, PLATE_H + 5, { width: 80 }), { italic: true, lineHeight: 1.3 }),
    label('source', '{attr.source}', 7.5, at('top', 0, PLATE_H + 16), 'muted', 1.3),
  ]) },
  { id: 'title', ...blind, advancedDesign: design([ // v: four frontmatter fields, one attribute
    // {publishDate} prints because the year is quoted (gotcha: quote-frontmatter).
    label('edition', 'The text of {publishDate}', 7.5, at('top', 0, 22), 'accent', 1.8),
    text('title', '{title}', 'Playfair Display SC', 33, at('top', 0, 30),
      { fontWeight: 700, letterSpacing: pt(0.4), lineHeight: 1 }),
    text('subtitle', '{subtitle}', 'Fanwood Text', 14, at('top', 0, 44), { italic: true }),
    { kind: 'rule', id: 'rule', direction: 'horizontal', thickness: pt(0.8), color: col('accent'),
      placement: at('top', 0, 60, { width: 14 }) },
    label('author', '{author}', 10, at('top', 0, 66), 'ink', 2.4),
    image('mark', at('top', 0, 126, { width: 11 })),
    label('publisher', '{attr.publisher}', 7.5, at('top', 0, 140), 'muted', 1.5),
  ]) },
  // vi: the section's margins set the small print low, in a 70 mm measure against the outer
  // margin. With no element the design would print the title (gotcha: invisible-heading).
  { id: 'imprint', ...blind, margins: { top: mm(IMPRINT_TOP), left: mm(TRIM_W - OUTER - 70) },
    advancedDesign: design([{ kind: 'box', id: 'none', style: { backgroundColor: col('paper') },
      placement: { ...at('top-left', 0, 0), size: { width: pt(0.1), height: pt(0.1) } } }]) },
  // vii: dedication and epigraph, under a heading whose only element is an ornament, which
  // also keeps its title from printing (gotcha: invisible-heading).
  { id: 'quiet', ...blind,
    advancedDesign: design([image('crystal', at('top', 0, 24, { width: 6 }))], 34) },
];
// :::paragraphs blocks set the small print, the dedication, the epigraph and Walton's close;
// the dedication and the verse take one paragraph per line, so no line of them can reflow.
const VERSE_IN = 22; // mm: the indent that centres the verse as a block
const SOURCE_IN = 55; // mm: 'Paradise Lost' ends under the end of the longest line of verse
const prelimStyles = [
  // In ink, not muted: a paragraph style has no italic colour, so its italic title would take
  // bodyText.italicColor and print darker than its words (gotcha: style-italic-colour).
  { id: 'small-print', fontSize: pt(7.6), lineHeight: pt(10.4), textAlign: 'left',
    firstLineIndent: pt(0), spaceBetween: pt(5.2) },
  // Small capitals, with the italic lines of the 1818 page, leaded as one inscription.
  { id: 'dedication', fontFamily: 'Playfair Display SC', fontSize: pt(10), lineHeight: pt(15),
    textAlign: 'center', firstLineIndent: pt(0) },
  { id: 'verse', fontSize: pt(10), textAlign: 'left', firstLineIndent: mm(VERSE_IN),
    marginTop: pt(LEAD * 4) }, // on the body's 14 pt leading, which a style inherits
  { id: 'source', fontFamily: 'Cinzel', fontSize: pt(7.5), textAlign: 'left',
    firstLineIndent: mm(SOURCE_IN), marginTop: pt(4), color: col('muted') },
  { id: 'signature', textAlign: 'right', firstLineIndent: pt(0) }, // the letter's close
];
// #endregion

// #region contents: what :::toc prints: titles, dotted leaders, the labels each page prints
// Entries take the body's face and ink, and start on the Preface's first baseline, facing it.
const contents = {
  levels: [{ level: 1, fontSize: pt(12), lineHeight: pt(PREFACE.lead) }],
  // The folio's face: "ix" in small capitals, then a plain 1. The leader takes it too.
  pageNumber: { fontFamily: 'Playfair Display SC', fontSize: pt(10), color: col('accent'),
    width: mm(8) },
  leader: { char: '. ', gap: mm(2.5) },
  // A second line from the heading's to="…" attribute: whom each letter is written to.
  subtitle: { enabled: true, attr: 'to', fontSize: pt(9.5), color: col('muted') },
};
// #endregion

// #region letter: the novel's opener: the northern lights, bled off the head of the recto
const BAND = 104; // mm from the trim to the foot of the drawing, which fades into the paper
// minHeight ends AIR mm below it and the first line takes the next grid line. to: 'bleed' is the
// trim until page.cutLines adds a bleed; 3 mm drop the foot 1.8 mm, still above that line.
const AIR = 2;
const opener = design([
  image('band', at('top-left', 0, 0, { width: 'fill', to: 'bleed' })),
  label('to', '{attr.to}', 7.5, onPage(19), 'ice', 2),
  text('title', '{titleText}', 'Playfair Display SC', 46, onPage(25),
    { color: col('bone'), lineHeight: 1 }),
  text('dateline', '{attr.dateline}', 'Fanwood Text', 10.5, onPage(44),
    { italic: true, color: col('bone') }),
  // minHeight counts from the text block, TOP below the trim. The texts reserve their height,
  // the drawing nothing (gotcha: opener-image-no-reserve), so minHeight sets the first line.
], BAND - TOP + AIR);
// Walton's letters come before Chapter I: they take the novel's opener but no number.
const letter = { id: 'letter', numbered: false };
// #endregion

// #region heads: running heads on the novel's body pages; the book on versos, letter on rectos
const HEAD_Y = 12.5; // mm from the trim to the heads' line
const HEAD_GAP = 8; // mm from the outer margin, where the folio hangs, to the words beside it
const head = (id, content, parity, edge, x, extra = {}) => ({ ...label(id, content, 7.5,
  at(edge, x, HEAD_Y, { to: 'page' }), 'muted', 1.4), align: 'left', parity, pages: 'body',
  ...extra }); // pages: 'body' keeps them off the opener
const numeral = { fontFamily: 'Playfair Display SC', fontSize: pt(8.5), fontWeight: 400,
  letterSpacing: pt(0.6), color: col('ink') }; // folios in the folio face, as on the openers
const header = { elements: [
  head('verso-folio', '{pageNumber}', 'even', 'top-left', OUTER, numeral),
  head('verso-title', '{title}', 'even', 'top-left', OUTER + HEAD_GAP),
  head('recto-title', '{chapterTitle}', 'odd', 'top-right', -(OUTER + HEAD_GAP)),
  head('recto-folio', '{pageNumber}', 'odd', 'top-right', -OUTER, numeral),
] };
// #endregion

const config = () => ({ // a factory: the engine caches resolved configs per object
  locale: 'en-us', // hyphenation patterns, by exact code (gotcha: hyphenation-locales)
  colorPalette, layout: { layoutType: 'single' },
  page: { // mirror: left is the inner margin; 150 dpi is for the screen
    sizePreset: 'custom', width: mm(TRIM_W), height: mm(TRIM_H), dpi: 150,
    backgroundColor: col('paper'), pageNumbering,
    margins: { top: mm(TOP), bottom: mm(BOTTOM), left: mm(INNER), right: mm(OUTER), mirror: true },
  },
  bodyText: { // justified, hyphenated, optimal line breaking, widow control: the defaults
    fontFamily: 'Fanwood Text', fontSize: pt(10.5), lineHeight: pt(LEAD), color: col('ink'),
    boldColor: col('ink'), italicColor: col('ink'), referenceColor: col('ink'),
    firstLineIndent: mm(4), indentAfterHeading: false,
    // An even grey: spaces 0.75–1.75 of their width; a last line under 36 spaces' width (about
    // 18 letters: a lone 'occurrence.') is a runt, and costs three times the default.
    minWordSpacing: 0.75, maxWordSpacing: 1.75, runtMinCharacters: 36, runtPenalty: 3000,
  },
  headings: {
    fontFamily: 'Playfair Display SC', fontWeight: 400, color: col('ink'),
    // Break restated (gotcha: headings-drop-h1-break). span 'page' paints the opener unclipped,
    // so the drawing reaches the trim; an in-column design is clipped to the text block.
    levels: [{ level: 1, span: 'page', breakBefore: { enabled: true, parity: 'odd' },
      marginTop: pt(0), marginBottom: pt(0), advancedDesign: opener }],
  },
  headingStyles: [...leaves, front, letter],
  toc: contents,
  paragraphStyles: prelimStyles,
  header, footer,
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
title: "Frankenstein"
subtitle: "or, The Modern Prometheus"
author: "Mary Shelley"
publishDate: "1818"
---

# Cover {style="cover" publisher="Postext Classics"}

# Half title {style="half"}

# Frontispiece {style="plate" caption="We perceived a low carriage, fixed on a sledge and drawn by dogs, pass on towards the north, at the distance of half a mile." source="Letter IV"}

# Title page {style="title" publisher="Postext Classics · MMXXVI"}

# Imprint {style="imprint"}

:::paragraphs{style="small-print"}
*Frankenstein; or, The Modern Prometheus* was first published anonymously, in three volumes, by Lackington, Hughes, Harding, Mavor & Jones of Finsbury Square, London, on 1 January 1818.

This edition follows that first text, transcribed by Project Gutenberg from a photographic reprint (eBook 41445), and keeps its spelling: phænomena, their’s, St. Petersburgh.

Set in Fanwood Text, Playfair Display SC and Cinzel, all under the SIL Open Font License. Cover, frontispiece and publisher’s mark drawn in code; pages laid out in the browser by Postext.

Text: public domain. Design and editorial matter: CC BY 4.0.

Postext Cookbook · No. 6
:::

# Dedication {style="quiet"}

:::paragraphs{style="dedication"}
*To*

William Godwin,

*Author of Political Justice,*

*Caleb Williams, &c.*

These volumes

*Are respectfully inscribed*

By

The Author.
:::

:::paragraphs{style="verse"}
*Did I request thee, Maker, from my clay*

*To mould me man? Did I solicit thee*

*From darkness to promote me?——*
:::

:::paragraphs{style="source"}
Paradise Lost
:::

# Contents {style="front"}

:::toc

# Preface {style="front" toc="true"}

The event on which this fiction is founded has been supposed, by Dr. Darwin, and some of the physiological writers of Germany, as not of impossible occurrence. I shall not be supposed as according the remotest degree of serious faith to such an imagination; yet, in assuming it as the basis of a work of fancy, I have not considered myself as merely weaving a series of supernatural terrors. The event on which the interest of the story depends is exempt from the disadvantages of a mere tale of spectres or enchantment. It was recommended by the novelty of the situations which it developes; and, however impossible as a physical fact, affords a point of view to the imagination for the delineating of human passions more comprehensive and commanding than any which the ordinary relations of existing events can yield.

I have thus endeavoured to preserve the truth of the elementary principles of human nature, while I have not scrupled to innovate upon their combinations. The *Iliad*, the tragic poetry of Greece,—Shakespeare, in the *Tempest* and *Midsummer Night’s Dream*,—and most especially Milton, in *Paradise Lost*, conform to this rule; and the most humble novelist, who seeks to confer or receive amusement from his labours, may, without presumption, apply to prose fiction a licence, or rather a rule, from the adoption of which so many exquisite combinations of human feeling have resulted in the highest specimens of poetry.

The circumstance on which my story rests was suggested in casual conversation. It was commenced, partly as a source of amusement, and partly as an expedient for exercising any untried resources of mind. Other motives were mingled with these, as the work proceeded. I am by no means indifferent to the manner in which whatever moral tendencies exist in the sentiments or characters it contains shall affect the reader; yet my chief concern in this respect has been limited to the avoiding of the enervating effects of the novels of the present day, and to the exhibitions of the amiableness of domestic affection, and the excellence of universal virtue. The opinions which naturally spring from the character and situation of the hero are by no means to be conceived as existing always in my own conviction; nor is any inference justly to be drawn from the following pages as prejudicing any philosophical doctrine of whatever kind.

It is a subject also of additional interest to the author, that this story was begun in the majestic region where the scene is principally laid, and in society which cannot cease to be regretted. I passed the summer of 1816 in the environs of Geneva. The season was cold and rainy, and in the evenings we crowded around a blazing wood fire, and occasionally amused ourselves with some German stories of ghosts, which happened to fall into our hands. These tales excited in us a playful desire of imitation. Two other friends (a tale from the pen of one of whom would be far more acceptable to the public than any thing I can ever hope to produce) and myself agreed to write each a story, founded on some supernatural occurrence.

The weather, however, suddenly became serene; and my two friends left me on a journey among the Alps, and lost, in the magnificent scenes which they present, all memory of their ghostly visions. The following tale is the only one which has been completed.

:::pagebreak{parity="odd"}

:::numbering{format="decimal" startAt=1}

# Letter I {style="letter" to="To Mrs. Saville, England" dateline="St. Petersburgh, Dec. 11th, 17—"}

You will rejoice to hear that no disaster has accompanied the commencement of an enterprise which you have regarded with such evil forebodings. I arrived here yesterday; and my first task is to assure my dear sister of my welfare, and increasing confidence in the success of my undertaking.

I am already far north of London; and as I walk in the streets of Petersburgh, I feel a cold northern breeze play upon my cheeks, which braces my nerves, and fills me with delight. Do you understand this feeling? This breeze, which has travelled from the regions towards which I am advancing, gives me a foretaste of those icy climes. Inspirited by this wind of promise, my day dreams become more fervent and vivid. I try in vain to be persuaded that the pole is the seat of frost and desolation; it ever presents itself to my imagination as the region of beauty and delight. There, Margaret, the sun is for ever visible; its broad disk just skirting the horizon, and diffusing a perpetual splendour. There—for with your leave, my sister, I will put some trust in preceding navigators—there snow and frost are banished; and, sailing over a calm sea, we may be wafted to a land surpassing in wonders and in beauty every region hitherto discovered on the habitable globe. Its productions and features may be without example, as the phænomena of the heavenly bodies undoubtedly are in those undiscovered solitudes. What may not be expected in a country of eternal light? I may there discover the wondrous power which attracts the needle; and may regulate a thousand celestial observations, that require only this voyage to render their seeming eccentricities consistent for ever. I shall satiate my ardent curiosity with the sight of a part of the world never before visited, and may tread a land never before imprinted by the foot of man. These are my enticements, and they are sufficient to conquer all fear of danger or death, and to induce me to commence this laborious voyage with the joy a child feels when he embarks in a little boat, with his holiday mates, on an expedition of discovery up his native river. But, supposing all these conjectures to be false, you cannot contest the inestimable benefit which I shall confer on all mankind to the last generation, by discovering a passage near the pole to those countries, to reach which at present so many months are requisite; or by ascertaining the secret of the magnet, which, if at all possible, can only be effected by an undertaking such as mine.

These reflections have dispelled the agitation with which I began my letter, and I feel my heart glow with an enthusiasm which elevates me to heaven; for nothing contributes so much to tranquillize the mind as a steady purpose,—a point on which the soul may fix its intellectual eye. This expedition has been the favourite dream of my early years. I have read with ardour the accounts of the various voyages which have been made in the prospect of arriving at the North Pacific Ocean through the seas which surround the pole. You may remember, that a history of all the voyages made for purposes of discovery composed the whole of our good uncle Thomas’s library. My education was neglected, yet I was passionately fond of reading. These volumes were my study day and night, and my familiarity with them increased that regret which I had felt, as a child, on learning that my father’s dying injunction had forbidden my uncle to allow me to embark in a sea-faring life.

These visions faded when I perused, for the first time, those poets whose effusions entranced my soul, and lifted it to heaven. I also became a poet, and for one year lived in a Paradise of my own creation; I imagined that I also might obtain a niche in the temple where the names of Homer and Shakespeare are consecrated. You are well acquainted with my failure, and how heavily I bore the disappointment. But just at that time I inherited the fortune of my cousin, and my thoughts were turned into the channel of their earlier bent.

Six years have passed since I resolved on my present undertaking. I can, even now, remember the hour from which I dedicated myself to this great enterprise. I commenced by inuring my body to hardship. I accompanied the whale-fishers on several expeditions to the North Sea; I voluntarily endured cold, famine, thirst, and want of sleep; I often worked harder than the common sailors during the day, and devoted my nights to the study of mathematics, the theory of medicine, and those branches of physical science from which a naval adventurer might derive the greatest practical advantage. Twice I actually hired myself as an under-mate in a Greenland whaler, and acquitted myself to admiration. I must own I felt a little proud, when my captain offered me the second dignity in the vessel, and entreated me to remain with the greatest earnestness; so valuable did he consider my services.

And now, dear Margaret, do I not deserve to accomplish some great purpose. My life might have been passed in ease and luxury; but I preferred glory to every enticement that wealth placed in my path. Oh, that some encouraging voice would answer in the affirmative! My courage and my resolution is firm; but my hopes fluctuate, and my spirits are often depressed. I am about to proceed on a long and difficult voyage; the emergencies of which will demand all my fortitude: I am required not only to raise the spirits of others, but sometimes to sustain my own, when their’s are failing.

This is the most favourable period for travelling in Russia. They fly quickly over the snow in their sledges; the motion is pleasant, and, in my opinion, far more agreeable than that of an English stage-coach. The cold is not excessive, if you are wrapt in furs, a dress which I have already adopted; for there is a great difference between walking the deck and remaining seated motionless for hours, when no exercise prevents the blood from actually freezing in your veins. I have no ambition to lose my life on the post-road between St. Petersburgh and Archangel.

I shall depart for the latter town in a fortnight or three weeks; and my intention is to hire a ship there, which can easily be done by paying the insurance for the owner, and to engage as many sailors as I think necessary among those who are accustomed to the whale-fishing. I do not intend to sail until the month of June: and when shall I return? Ah, dear sister, how can I answer this question? If I succeed, many, many months, perhaps years, will pass before you and I may meet. If I fail, you will see me again soon, or never.

Farewell, my dear, excellent, Margaret. Heaven shower down blessings on you, and save me, that I may again and again testify my gratitude for all your love and kindness.

:::paragraphs{style="signature"}
*Your affectionate brother,*

R. Walton.
:::
`; // content.<lang>.md, inlined by the Cookbook

// #region art: the publisher's mark and an ice crystal, drawn in the palette
const f = (n) => n.toFixed(2);
const poly = (pts, fill, a = 1) => `<path d="M${pts.map(([x, y]) => `${f(x)} ${f(y)}`).join('L')}Z"`
  + ` fill="${fill}" fill-opacity="${a}"/>`;
const disk = (x, y, r, fill, a = 1) => `<circle cx="${f(x)}" cy="${f(y)}" r="${f(r)}" `
  + `fill="${fill}" fill-opacity="${a}"/>`;
const PX = 10; // each drawing is w × h mm in its viewBox and declares w·PX × h·PX pixels
const svgOf = (w, h, body) => `<svg xmlns="http://www.w3.org/2000/svg" width="${w * PX}" `
  + `height="${h * PX}" viewBox="0 0 ${w} ${h}">${body}</svg>`;
// The publisher's mark: a polar star in a double ring. The ornament: an ice crystal.
const EMBLEM = 40; // mm: both are drawn on a 40 × 40 viewBox
function mark() {
  const star = [];
  for (let i = 0; i < 16; i++) {
    const a = (i * Math.PI) / 8;
    const rr = i % 4 === 0 ? 13 : i % 2 === 0 ? 7 : 2.6;
    star.push([20 + rr * Math.sin(a), 20 - rr * Math.cos(a)]);
  }
  const rings = [[19, 'accent'], [18, 'paper'], [16.2, 'accent'], [15.6, 'paper']];
  return svgOf(EMBLEM, EMBLEM, rings.map(([rr, c]) => disk(20, 20, rr, palette[c])).join('')
    + poly(star, palette.ink));
}
function crystal() {
  const arm = poly([[19.5, 20], [19.5, 3], [20, 1.5], [20.5, 3], [20.5, 20]], palette.accent)
    + poly([[20, 9], [15, 5], [15.5, 4.4], [20, 7.8], [24.5, 4.4], [25, 5]], palette.accent);
  return svgOf(EMBLEM, EMBLEM, [0, 60, 120, 180, 240, 300].map((a) =>
    `<g transform="rotate(${a} 20 20)">${arm}</g>`).join('') + disk(20, 20, 2.4, palette.accent));
}
for (const [id, svg] of Object.entries({ mark: mark(), crystal: crystal() })) {
  await loadSvg(`${id}.svg`, svg);
}
// Each declares svgOf's pixel size.
const svgResource = (id, w, h, altText) => ({ id, typeId: 'figure', kind: 'svg', altText,
  createdAt: 0, updatedAt: 0, svg: { fileId: `${id}.svg`, width: w * PX, height: h * PX } });
const emblems = [
  svgResource('mark', EMBLEM, EMBLEM, 'Publisher’s mark: a polar star in a double ring.'),
  svgResource('crystal', EMBLEM, EMBLEM, 'Ornament: an ice crystal.'),
];
// #endregion

const painting = (id, w, h, altText) => ({ id, typeId: 'figure', kind: 'bitmap', altText,
  createdAt: 0, updatedAt: 0,
  bitmap: { fileId: `${id}-${w}.jpg`, format: 'jpeg', width: w, height: h } });
const paintings = [ // JPEGs in assets/; only the designs use them, nothing cites them
  painting('cover', 1000, 1535, 'Lightning strikes Mont Blanc over the lake of Geneva.'),
  painting('plate', 1000, 1299, 'A brig beset in pack ice, a sledge drawn by dogs far off.'),
  painting('band', 1400, 1129, 'Northern lights over the frozen Neva and St Petersburgh.'),
];
await Promise.all(paintings.map(({ bitmap: b }) => loadImage(b.fileId, asset(b.fileId))));
const resources = [...paintings, ...emblems];

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
// Loaded before the first build (gotcha: fonts-first). The PDF asks for a bold Fanwood and an
// italic Cinzel too; the kit's provider snaps to shipped faces (gotcha: pdf-provider-all-styles).
const FONTS = { 'Fanwood Text': ['400', '400i'], Cinzel: ['400', '600'],
  'Playfair Display SC': ['400', '400i', '700'] };

// ─── 4 · Build & show ───────────────────────────────────────────────────────
// #region build: lay out once (buildDocument settles the contents), show, offer a PDF
await loadFonts(FONTS, markdown);
// :::toc lists each heading with the label of the page it lands on; buildDocument lays the
// document out again until those labels stop moving (ix for the Preface, 1 for Letter I).
const doc = await buildWithFonts(() => buildDocument({ markdown, resources }, config()), markdown);
showPages(doc, { title: 'Frankenstein · the opening leaves' });
// The PDF gets /PageLabels from the same labels: a viewer numbers its pages i–x, then 1, 2.
offerPdf(() => renderToPdf(doc, { fontProvider: fontsourceProvider, resourceBytes: imageBytes }),
  `${RECIPE}.pdf`);
// #endregion

// ─── Kit ── helpers shared by every Cookbook recipe · postext.dev/cookbook ─────

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

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

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

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

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

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

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

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

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

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

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

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

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

// ─── Kit · pdf v1 ── the same in every recipe that exports a PDF ──────────────
/** postext-pdf embeds TrueType bytes. Fetch the Fontsource file the screen
 *  used, snapping to a weight the family ships and falling back to upright
 *  when it has no italic: the PDF asks for every face a block could use. */
async function fontsourceProvider(family, weight, style) {
  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 res = await fetch(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-${w}-${s}.woff2`);
  if (!res.ok) throw new Error(`Fontsource has no ${family} ${w} ${s} (${res.status})`);
  return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
}

/** A "Build the PDF" button in the bar. Once built: "Open the PDF" (a new
 *  tab, since CodePen's preview frame cannot show 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 ───────────────────────────────────────────────────────────────────────
```

## アレンジ

### 前付けを大文字で数える

大文字のローマ数字はノンブルの書体でフルサイズのキャピタルになり、小文字の数字が出すスモールキャピタルより背が高くなります。

```diff
-const pageNumbering = { format: 'lower-roman', startAt: 1 }; // startAt spelled out: cover = i
+const pageNumbering = { format: 'upper-roman', startAt: 1 }; // startAt spelled out: cover = I
```

### 通しで番号を振る

`startAt`を外すと算用数字のまま数え続けるので、Letter Iは11ページになります。前付けを本文と通しで数える本と同じです。

```diff
-:::numbering{format="decimal" startAt=1}
+:::numbering{format="decimal"}
```

### 口絵を外す

`# Frontispiece`見出しを削除し、本扉を奇数ページへ送ります。ivページは白ページのまま残り、序文はixのまま、Letter Iも1のままです。

```diff
-  { id: 'title', ...blind, advancedDesign: design([ // v: four frontmatter fields, one attribute
+  { id: 'title', ...blind, breakBefore: { enabled: true, parity: 'odd' },
+    advancedDesign: design([ // v: four frontmatter fields, one attribute
```

### 印刷用に塗り足しとトンボを付ける

`cutLines`を指定すると、どちらも塗り足しに固定した表紙と章扉が、仕上がりから3 mm外へ延びます。ノンブルとページ数は変わりません（[トンボ](/ja/docs/configuration#トンボ)）。

```diff
     backgroundColor: col('paper'), pageNumbering,
+    cutLines: { enabled: true }, // a 3 mm bleed and crop marks
```

## よくあるつまずき

- **:::numberingは次のページから効く.** :::numberingは、現在のページではなく、次に始まるページから番号を変えます。:::pagebreak（第1章の前ならparity odd）の直後に置けば、新しい番号付けが意図した位置から始まります。
- **見出しスタイルはその階層の改ページを受け継ぐ.** headingStylesの項目は、指定しなかったフィールドをすべて見出しの階層から受け継ぎ、breakBeforeも例外ではありません。:::pagebreakのあとのH1に付けた目次や奥付のスタイルはparity 'odd'を受け継ぎ、白ページの後ろに置かれます。こうしたスタイルにはbreakBefore: { enabled: false }を指定してください。
- **何も印字しない見出しには要素1つのデザインが要る.** 構造のためだけの見出し（奥付や献辞）も印字されます。ページ幅の見出しには{titleText}の章扉が自動で作られ、段内の見出しはテキストが出ます。見えない要素を1つだけ持つ詳細デザイン（たとえば0.1 ptの箱）を与えてください。
- **1ページは奇数ページ。ページは物理的な番号で計画する.** 1ページは右ページで、2ページが最初の偶数ページです。見開きは物理的なページ番号で計画してください。偶数ページの章扉は、その次の奇数ページと向かい合います。
- **リストは'arabic'、リソースは'roman-upper'、ページは'upper-roman'.** 番号付けの設定は、それぞれ書式の綴りが異なります。リストのnumberFormatは'arabic'（'decimal'では「undefined」と印字されます）、リソースの種類のcounterFormatは'roman-upper'、ページと:::numberingは'upper-roman'です。
- **フロントマターの値はすべて引用符で囲む.** YAMLはtitle: 1984を数値として、日付をDateオブジェクトとして読みます。文字列でない値はプレースホルダーに空で出力され、PDFにもタイトルが付きません。値はすべて引用符で囲んでください（title: "1984"）。
- **headingsオブジェクトを渡すとH1の改ページが消える.** 既定ではH1は奇数ページへ改ページします（always-odd）。ところがheadingsオブジェクトを渡すと中身にかかわらずこの既定がリセットされ、章は改ページせずに続けて組まれ、span: 'page'も効かなくなります。どの設定でもheadings.levels[0].breakBefore: { enabled: true, parity }を書き直してください。
- **段落スタイルにはイタリックの色がない.** postext 1.4.1の段落スタイルはcolorとboldColorを設定できますが、italicColorはなく、イタリックの部分はbodyText.italicColorを使います。抑えた色のスタイル（小さな注記、出典の行）では、イタリックの書名が周りの文字より濃く印字されます。こうしたスタイルは本文と同じ色にするか、その中でイタリックを使わないでください。
- **ノーブレークスペースでも改行される.** postext 1.4.1の改行処理はU+00A0を通常のスペースとして扱うため、0.08 %、2.006 s、Section 2などが2行に分かれることがあります。間を詰める（0.08%）か、文を書き換えてください。
- **PDFはすべてのファミリーのすべてのウェイトとスタイルを要求する.** renderToPdfは、ブロックが使う可能性のあるすべてのファミリーについて、実際には印字されないものも含め、ボールド、イタリック、ボールドイタリックのフォントをフォントプロバイダーに求めます。1つでも拒否されると書き出しが止まります。プロバイダーは、そのファミリーが持つ最も近いウェイトを返し、イタリックがなければ立体にフォールバックする必要があります。
- **章扉の画像は確保する高さに数えられない.** postext 1.4.1では、詳細デザインの見出しは、確保する高さを画像抜きで計測します。テキスト、罫、箱はページに固定していても数えられますが、ページの頭に裁ち落としで置いた写真のような画像は何も確保しないため、本文がその上から始まることがあります。minHeightを本文が始まるべき位置に設定してください。
- **ページのヘッダーは、そのページで始まる最後の節のものになる.** 1つのページで2つの見出しスタイルが始まると、そのページのヘッダー、フッター、パレットは後のほうのものになります。区切りの白ページは前の章に、奇数・偶数合わせの白ページは後の章に属します。
- **組版の警告: 奇偶指定の連鎖** (`parityCascade`). 奇偶指定の改ページが重なり、白ページが3ページ以上続いています。 解決策: always-oddの改ページとbreakBeforeの奇偶指定を見直してください。短い章では、parityをanyにすると白ページを避けられることが多くあります。 ([ドキュメント](https://postext.dev/ja/docs/configuration.md#前で改ページ))
- **組版の警告: 無効な番号書式** (`numberingInvalidFormat`). :::numberingのformatが、decimal、lower-roman、upper-roman、lower-alpha、upper-alphaのいずれでもありません。 解決策: ノンブル用の5つの形式のいずれかを使ってください。リストやリソースでは形式の綴りが異なります。 ([ドキュメント](https://postext.dev/ja/docs/document-format.md#numbering))

- 丁はレベル1の`'odd'`改ページを継承します。そのままにすると、どの丁も右ページを待ちます。前付けは10ページでなく14ページになって白い偶数ページが4つ増え、口絵は本扉ではなく白ページと向かい合います。このレシピのように`parity: 'any'`で改ページを指定し直すか、`breakBefore: { enabled: false }`で外してください。ページ幅の見出しは、どちらの場合もそれ自身のページを開きます。
- レベル1が`'always-odd'`（エンジンのH1の初期値）で改ページする場合は、`:::numbering`の前の`:::pagebreak`を外してください。その前の本文が右ページで終わると、pagebreakが次の奇数ページまで埋め、見出しが区切りのページを足してもう一度埋めるので、白ページが1つでなく3つ続きます。ここでのように`'odd'`改ページのあとでは、pagebreakは何も変えません。`'any'`のあとでは、これが1ページ目を奇数ページに置きます。
- 序文が1ページ増えると、Letter Iは2ページ先へ移ります。奇数ページへの改ページが、その前に白い偶数ページを足すからです。前付けを編集したら、そのつどページ数を確認してください。
- 章扉の文字は版面の下端より上に収めます。Postext 1.4.1では、見出しのデザインがそれより下まで伸びると、`minHeight`を含めて確保した高さがすべて失われます。表紙はあとに本文が続かないので何も変わりませんが、章扉では本文が題名のすぐ下から始まってしまいます。
- 目次のリーダー点はページ番号の書体と色で組まれ、`toc.leader`には独自の色がありません。そのためここではスチールブルーで刷られます。

## クレジット

- レシピ: Ignacio Ferro ([@drnachio](https://github.com/drnachio))
- テキスト: Frankenstein; or, The Modern Prometheus (1818): the dedication, Letter I, a line of Letter IV (the frontispiece caption) and one of volume I, chapter VI (quoted in a code comment): Mary Shelley ([出典](https://www.gutenberg.org/ebooks/41445)), パブリックドメイン
- テキスト: The unsigned Preface of the 1818 edition (by common attribution): Percy Bysshe Shelley ([出典](https://www.gutenberg.org/ebooks/41445)), パブリックドメイン
- テキスト: Paradise Lost (1667), book X, lines 743–745: the epigraph of the 1818 title leaves: John Milton ([出典](https://www.gutenberg.org/ebooks/26)), パブリックドメイン
- 画像: The cover: lightning over Mont Blanc and the lake of Geneva: Generated With Diffusion Models, オリジナル
- 画像: The frontispiece: a brig beset in pack ice, a dog sledge far off: Generated With Diffusion Models, オリジナル
- 画像: Letter I’s opener: northern lights over the frozen Neva: Generated With Diffusion Models, オリジナル
- 書体: Fanwood Text (OFL-1.1), Playfair Display SC (OFL-1.1), Cinzel (OFL-1.1)
- コード: MIT · サンプルの内容: CC-BY-4.0

## 関連レシピ

- [No. 019 · ひとつの属性で部ごとに色を変える](https://postext.dev/ja/cookbook/parts-in-colour.md): ポケット判の野外図鑑。:::partごとにパレットの1項目を設定し、部扉、色を敷いた偶数ページ、つめ見出し、識別点、目次の行をその色で刷ります。 · 難易度 3 (上級) · マニュアル・ガイド・リファレンス
- [No. 015 · 詩を1行ずつ組む](https://postext.dev/ja/cookbook/poetry-collection.md): 詩の各行を1段落とし、折り返しを4 em下げてぶら下げます。1918年版のインデントはemスペースで保ち、:::spaceで連の間に1行空けます。 · 難易度 2 (中級) · 詩歌
- [No. 023 · 雑誌の表紙とセクション別の目次](https://postext.dev/ja/cookbook/magazine-cover-and-contents.md): 写真の表紙では表紙コピーが題字から吊り下がり、目次はセクションごとに色の行を立てて生成されます。各セクションは、ページを開かない部です。 · 難易度 3 (上級) · 雑誌とジン