CV di una pagina con barra laterale

// ═══ Postext Cookbook · Nº 057 · One-page CV with a sidebar ═══════════════════════
// https://postext.dev/en/cookbook/cv-with-sidebar
// Code: MIT · Text: original (CC BY 4.0) · Drawing: made in code (CC BY 4.0)
// Fonts: Hedvig Letters Serif, Hanken Grotesk (SIL OFL 1.1) · Needs postext ≥ 1.25.0
import {
  buildDocumentWithFonts, renderPageToCanvas, registerResourceImage,
} from 'https://esm.sh/postext';

const LANG = 'en'; // @lang: the language of the sample document ('en' | 'es')
const RECIPE = 'cv-with-sidebar';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
const palette = {
  ink: '#231b22', // text: a plum-tinted near-black
  band: '#3a2235', // the sidebar
  accent: '#8f3b62', // on paper: the role and the section heads (7.1:1)
  glow: '#f1b98f', // on the band: the sidebar titles (8.3:1)
  chip: '#744d6c', // on the band: the skill chips
  rule: '#d9cdd5', // the hairlines after the section heads
  muted: '#6c5f69', // dates, employers, the colophon (6.0:1)
  paper: '#ffffff', // the page, and the text on the band (14.4:1)
};
// Each colour carries its hex and the palette entry it follows.
const col = (id) => ({ hex: palette[id], model: 'hex', paletteId: id });
const colorPalette = Object.entries({ ...palette, 'main-color': palette.accent })
  .map(([id, hex]) => ({ id, name: id, value: { hex, model: 'hex' } }));
const [SERIF, SANS] = ['Hedvig Letters Serif', 'Hanken Grotesk'];
const PT = 25.4 / 72; // mm in a point
const [TRIM_W, TRIM_H] = [210, 297]; // mm: A4, printed on one side, so nothing is mirrored
const [TOP, LEFT, RIGHT] = [18, 9, 16]; // mm
const LEAD = 13.2; // pt: the body leading
const BOTTOM = TRIM_H - TOP - 56 * LEAD * PT; // mm: the text block holds 56 lines
const CONTENT = TRIM_W - LEFT - RIGHT; // 185 mm between the margins
const [SIDE, GUTTER] = [57, 10]; // mm: the sidebar column, and the white after it
const at = (to, edge, x = 0, y = 0) => ({ anchor: { to, edge }, offset: { x: mm(x), y: mm(y) } });
const LABEL = 7.8; // pt: the role and the sidebar titles, tracked capitals
const caps = (colour) => ({ fontFamily: SANS, fontSize: pt(LABEL), fontWeight: 700,
  textTransform: 'uppercase', letterSpacing: pt(LABEL * 0.18), color: col(colour) });
const NAME = { size: 46, gap: 2.6 }; // pt and mm: the name, and the room under it
const ROLE_Y = NAME.size * PT + NAME.gap; // mm under the top margin: the role's line
// mm under the top margin: the name's baseline. Hedvig Letters Serif, set solid, puts it 0.795
// of the size down the line (measured on the page); another face needs its own ratio.
const BASELINE = 0.795 * NAME.size * PT;
const BOOKS = { w: 46, h: 18 }; // mm: the drawing at the head of the band

// #region answer: a float-only column on the left, filled by one box
const layout = {
  layoutType: 'oneAndHalf',
  sideColumnPercent: (SIDE / CONTENT) * 100, // 57 of the 185 mm between the margins
  sideColumnSide: 'left',
  sideColumnRole: 'floats', // no body text: only boxes fenced with span="side"
  gutterWidth: mm(GUTTER), // the text column keeps 185 − 57 − 10 = 118 mm
};
// A side box stands where the text has reached at its fence, so the Markdown opens with it,
// before the name, and it starts at the head of the column (gotcha: side-box-starts-at-fence):
//   :::callout{type="sidebar" span="side"}
//   :::callout{type="section" title="Contact"} … :::     ← the sections nest inside it
//   …
//   :::space{lines=2.76}    ← last: runs the band to the column's foot; a fifth of a line
//   :::                       more and the whole box moves to page 2
//   # Irene Salcedo {role="Book designer and art director"}
const sidebar = { id: 'sidebar', background: col('band'),
  // The first title stands on the role's line. The text starts 10 mm from the trim, the
  // left margin plus 1 mm, and stops 10 mm short of the band's right edge.
  padding: { top: mm(ROLE_Y), right: mm(10), bottom: pt(0), left: mm(1) },
  body: { fontFamily: SANS, fontSize: pt(8.4), lineHeight: pt(12.4), color: col('paper'),
    boldColor: col('paper'), paragraphSpacing: false } };
// #endregion

// #region margins: header boxes paint the band into the margins around the column
// Header elements are painted after the text, over it, so these stay in the margins, where
// no text runs (gotcha: header-paints-over-text). They repeat on every page.
const BAND_W = LEFT + SIDE; // mm from the trim edge to the band's right edge
const SEAM = 0.5; // mm of overlap with the box, so no hairline of paper shows between them
const REACH = 1; // mm the foot box climbs above the column's foot, over the end of the box
const bandBox = (id, x, y, w, h) => ({ kind: 'box', id, style: { backgroundColor: col('band') },
  placement: { ...at('page', 'top-left', x, y), size: { width: mm(w), height: mm(h) } } });
const header = { elements: [
  bandBox('head', 0, 0, BAND_W, TOP + SEAM), // above the column: the top margin
  bandBox('edge', 0, 0, LEFT + SEAM, TRIM_H), // beside it: the left margin, top to bottom
  bandBox('foot', 0, TRIM_H - BOTTOM - REACH, BAND_W, BOTTOM + REACH), // below it
  // Painted last, over the box's top padding, where no text runs. The bottom of the stack
  // sits on the name's baseline.
  { kind: 'image', id: 'books', resourceId: 'books', placement: {
    ...at('page', 'top-left', LEFT + 1, TOP + BASELINE - BOOKS.h),
    size: { width: mm(BOOKS.w), height: mm(BOOKS.h) } } },
] };
// #endregion

// #region sections: boxes nested in the band, one per section; chips for the skills
// The sections nest in one side box. As separate side boxes they would stand at least a line
// of paper apart (gotcha: side-boxes-line-apart). A nested box ignores span and flows inside
// its parent (gotcha: nested-callout-limits).
const section = (id, lineHeight) => ({ id, backgroundEnabled: false, // the band shows through
  padding: { top: pt(0), right: pt(0), bottom: pt(0), left: pt(0) },
  marginTop: mm(10),
  titleStyle: { ...caps('glow'), gap: mm(2.4) },
  body: { ...sidebar.body, lineHeight: pt(lineHeight) } });
const chipStyles = [{ id: 'skill', fontFamily: SANS, fontSize: pt(7.6), bold: true,
  background: col('chip'), color: col('paper'), borderWidth: pt(0),
  borderRadius: em(1), // past half the chip's height: a pill
  paddingX: em(0.6), paddingY: em(0.22), gap: em(0.3) }];
// #endregion

// #region name: the H1 sets the name and the role at the head of the text column
const nameplate = { enabled: true, slot: { elements: [
  { kind: 'text', id: 'name', content: '{titleText}', fontFamily: SERIF,
    fontSize: pt(NAME.size), lineHeight: 1, color: col('ink'),
    placement: at('container', 'top-left') },
  { kind: 'text', id: 'role', content: '{attr.role}', ...caps('accent'),
    placement: at('#name', 'below', 0, NAME.gap) },
] } };
const nameLevel = { level: 1, // span stays 'column': the name heads the text column only
  // No break before the name: the sidebar box is already on the page, and a break would
  // move the name and the whole text column to page 2.
  breakBefore: { enabled: false },
  marginBottom: pt(LEAD), // one grid line of air under the role
  advancedDesign: nameplate };
// #endregion

const sectionHead = { enabled: true, slot: { elements: [
  { kind: 'text', id: 'title', content: '{titleText}', fontFamily: SERIF, fontSize: pt(14),
    lineHeight: 20 / 14, color: col('accent'), placement: at('container', 'top-left') },
  { kind: 'rule', id: 'rule', direction: 'horizontal', thickness: pt(0.5), color: col('rule'),
    // 3 mm after the title, level with the middle of its lower case, on to the column's edge
    placement: { ...at('#title', 'right-of', 3, 3.9), size: { width: 'fill' } } },
] } };

// #region jobs: each job heading sets the title left and the dates flush right
const JOB = 9.8; // pt: the job title, the dates and the employer share the size and leading
const jobText = (id, content, look) => ({ kind: 'text', id, content, fontFamily: SANS,
  fontSize: pt(JOB), lineHeight: LEAD / JOB, // the body's leading, as a multiple of the size
  align: 'left', ...look }); // without align, design text is centred in its box
const job = { enabled: true, slot: { elements: [
  jobText('title', '{titleText}', { fontWeight: 700, color: col('ink'), overflow: 'wrap',
    placement: { ...at('container', 'top-left'), size: { width: mm(84) } } }), // clear of dates
  jobText('dates', '{attr.dates}', { color: col('muted'),
    placement: at('container', 'top-right') }), // the title's top and size, so its baseline
  jobText('org', '{attr.org}', { italic: true, color: col('muted'),
    placement: at('#title', 'below') }),
] } };
const jobLevel = { level: 3, fontSize: pt(JOB), lineHeight: pt(LEAD), marginTop: pt(9),
  marginBottom: pt(0), advancedDesign: job };
// The section head takes 20 pt under 19.6 pt of space, three grid lines, so a job head
// starts the same 9 pt under a grid line after a section head as after a list. The 9 pt
// below it merge with a job head's 9 pt above. Under Selected books they push the list to
// the next grid line, as the default 7 pt would; with 0 it would start one line higher.
const sectionLevel = { level: 2, fontSize: pt(14), lineHeight: pt(20),
  marginTop: pt(3 * LEAD - 20), marginBottom: pt(9), advancedDesign: sectionHead };
// #endregion

const config = () => ({
  colorPalette, layout, chipStyles, header, footer: { elements: [] },
  locale: t({ en: 'en-us', es: 'es' }), // the language of each edition, and of its bundle
  page: { sizePreset: 'custom', width: mm(TRIM_W), height: mm(TRIM_H), dpi: 150,
    margins: { top: mm(TOP), bottom: mm(BOTTOM), left: mm(LEFT), right: mm(RIGHT) } },
  bodyText: { fontFamily: SANS, fontSize: pt(9.3), lineHeight: pt(LEAD), color: col('ink'),
    italicColor: col('ink'), // the titles in Selected books
    referenceColor: col('ink'), // no :ref yet; one added later prints in ink, not default blue
    textAlign: 'left', firstLineIndent: pt(0), paragraphSpacing: true },
  // Each level draws its own design. The headings still name the text face, so the config
  // asks for no face beyond FONTS: their default is Open Sans.
  headings: { fontFamily: SANS, levels: [nameLevel, sectionLevel, jobLevel] },
  unorderedLists: { bulletChar: '–', color: col('ink'), fontWeight: 400, itemSpacing: pt(0),
    marginTop: pt(0), marginBottom: pt(0) },
  paragraphStyles: [
    { id: 'lead', fontSize: pt(11), lineHeight: pt(16) },
    { id: 'colophon', fontSize: pt(7), lineHeight: pt(9.6), color: col('muted'),
      marginTop: pt(LEAD) },
  ],
  calloutStyles: [sidebar, section('section', 12.4), section('chips', 16)],
});

// #region art: a stack of cloth-bound books, drawn in the palette
function books() { // BOOKS.w × BOOKS.h mm, in tenths of a millimetre; the bottom book first
  const lilac = mix(palette.band, palette.paper, 0.55);
  const stack = [ // [left edge, length, thickness, cloth, label]
    [0, 430, 40, palette.glow, palette.paper],
    [22, 380, 32, palette.paper, palette.accent],
    [6, 400, 36, palette.accent, palette.glow],
    [40, 330, 30, lilac, palette.paper],
    [18, 300, 34, mix(palette.glow, palette.paper, 0.45), palette.accent],
  ];
  let y = BOOKS.h * 10;
  let art = '';
  for (const [x, length, thick, cloth, label] of stack) {
    y -= thick;
    const [top, h] = [y + 3, thick - 3]; // a dark hairline above each book
    art += `<rect x="${x}" y="${top}" width="${length}" height="${h}" rx="3" fill="${cloth}"/>`
      + `<rect x="${x + 14}" y="${top}" width="5" height="${h}" fill="${label}"/>` // bands
      + `<rect x="${x + length - 19}" y="${top}" width="5" height="${h}" fill="${label}"/>`
      + `<rect x="${x + length * 0.34}" y="${top + h * 0.28}" width="${length * 0.32}" `
      + `height="${h * 0.44}" rx="2" fill="${label}"/>`; // the title label
  }
  return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${BOOKS.w * 10} ${BOOKS.h * 10}" `
    + `width="${BOOKS.w * 10}" height="${BOOKS.h * 10}">${art}</svg>`;
}
function mix(a, b, k) { // a blend of two palette colours, k of the way from a to b
  const rgb = (hex) => [1, 3, 5].map((i) => parseInt(hex.slice(i, i + 2), 16));
  const [p, q] = [rgb(a), rgb(b)];
  return `#${p.map((v, i) => Math.round(v + (q[i] - v) * k).toString(16).padStart(2, '0'))
    .join('')}`;
}
// #endregion

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
Esempio Markdown · 89 righe · content.en.md
title: "Irene Salcedo · Curriculum vitae"
author: "Irene Salcedo"
---

:::callout{type="sidebar" span="side"}
:::callout{type="section" title="Contact"}
Madrid, Spain

irene@salcedo.example

salcedo.example/books
:::

:::callout{type="chips" title="Skills"}
:chip[Book typography]{style="skill"} :chip[Series design]{style="skill"} :chip[Covers]{style="skill"} :chip[Grids and styles]{style="skill"} :chip[Typesetting]{style="skill"} :chip[Prepress]{style="skill"} :chip[Colour proofing]{style="skill"} :chip[EPUB 3]{style="skill"} :chip[Accessible PDF]{style="skill"} :chip[Art direction]{style="skill"}
:::

:::callout{type="chips" title="Tools"}
:chip[InDesign]{style="skill"} :chip[Illustrator]{style="skill"} :chip[Photoshop]{style="skill"} :chip[Glyphs]{style="skill"} :chip[Python]{style="skill"}
:::

:::callout{type="section" title="Languages"}
**Spanish** · native

**Catalan** · C2

**English** · C1, working language

**Italian** · B2
:::

:::callout{type="section" title="Education"}
**MA in Book Design**

Escuela del Libro del Turia, Valencia, 2011–2012

:::space{lines=0.5}

**BA in Graphic Design**

Escuela de Diseño Almenara, Castellón, 2007–2011
:::

:::callout{type="section" title="Teaching"}
Guest tutor in book typography at the Escuela del Libro del Turia, spring terms 2022–2024
:::

:::callout{type="section" title="Outside work"}
Letterpress printing at a shared workshop in Lavapiés; walking the long-distance paths of the Sierra de Guadarrama.
:::

:::space{lines=2.76}
:::

# Irene Salcedo {role="Book designer and art director"}

:::paragraphs{style="lead"}
Book designer with fourteen years in trade and academic publishing, the last five as art director of a house with three imprints. I work on series and covers as closely as on the page, and write the specifications printers work from. I am looking for an art director’s post with a literary or illustrated list.
:::

## Experience

### Art director {org="Ediciones del Albardín, Madrid" dates="2021 – present"}

- Set and maintain the house style of three imprints: 58 new titles in 2025, from pocket novels to illustrated non-fiction.
- Redesigned the pocket series on a 110 × 178 mm trim. Its grid holds 32 lines a page instead of 29, so the 2024 list needed about 9 per cent fewer pages than the 2023 list for the same number of titles.
- Lead two designers and a typesetter, and commission the illustrators and photographers for each season’s list.
- Moved print and ebook editions to one source file, so the ebook now ships the same week as the hardback.

### Senior book designer {org="Casa Albero, Barcelona" dates="2016 – 2021"}

- Designed interiors and covers for about 40 titles a year of literary fiction and essays, in Spanish and Catalan.
- Wrote the typesetting rules for the Catalan list: hyphenation, the l·l, quotation marks and dialogue dashes.
- Designed the twelve volumes of the collected poems of Elvira Montcada, with the notes set in the margin.

### Designer and typesetter {org="Imprenta Quirós, Valencia" dates="2012 – 2016"}

- Set critical editions with notes on up to three levels, and the bibliographies and indexes that go with them, for two university presses.
- Prepared files for offset printing: imposition, colour proofs and the paper and binding specifications.

## Selected books

- *Los años del salitre*, Marta Ibarra. Albardín, 2023. Cover, interior and a two-colour map section.
- *Cartas desde Menorca*, Miquel Truyols. Casa Albero, 2019. A bilingual edition on facing pages.
- *Obra reunida*, Elvira Montcada. Casa Albero, 2018–2020. Twelve volumes in a cloth slipcase.

:::paragraphs{style="colophon"}
Set in Hedvig Letters Serif and Hanken Grotesk. Text: CC BY 4.0.
:::
`; // content.<lang>.md, inlined by the Cookbook

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
// Every face the design uses, loaded before the first build.
const FONTS = { 'Hedvig Letters Serif': ['400'], 'Hanken Grotesk': ['400', '400i', '700'] };

// ─── 4 · Build & show ───────────────────────────────────────────────────────
await loadSvg('books.svg', books());
const resources = [{ id: 'books', typeId: 'figure', kind: 'svg', createdAt: 0, updatedAt: 0,
  svg: { fileId: 'books.svg', width: BOOKS.w * 10, height: BOOKS.h * 10 },
  altText: t({ en: 'A stack of five cloth-bound books',
    es: 'Una pila de cinco libros encuadernados en tela' }) }];
const doc = await buildDocumentWithFonts({ markdown, resources }, config(), kitFonts(FONTS));
showPages(doc, { title: t({ en: 'One-page CV with a sidebar',
  es: 'Currículum de una página con barra lateral' }) });

Kit · core, fonts, viewer, images: uguale in ogni ricetta · 270 righe
// ─── Kit ── helpers shared by every Cookbook recipe · postext.dev/cookbook ─────

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

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

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

/** A face's Fontsource files, in a fixed order: latin, then latin-ext and greek
 *  when `text` needs them and the family ships them (kitSubsetsFor), each with
 *  its unicode-range. Null for a weight or slant Fontsource does not ship. */
async function fontsourceResolver(family, weight, style, { text = '' } = {}) {
  const id = fontsourceId(family);
  const meta = await fontsourceMeta(family);
  if (meta && !(meta.weights.includes(weight) && meta.styles.includes(style))) return null;
  kitStatus('Loading fonts…');
  const at = await fontsourceAt(id);
  return ['latin', ...kitSubsetsFor(text, meta)].map((subset) => ({
    source: `${at}files/${id}-${subset}-${weight}-${style}.woff2`,
    unicodeRange: kitRanges()[subset],
  }));
}

/** The unicode-range of each Fontsource file the kit loads (a function: the
 *  kit is inlined after the pen's code, which runs before a const would be set). */
function kitRanges() {
  return {
    latin: 'U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,'
      + 'U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD',
    'latin-ext': 'U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,'
      + 'U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF',
    greek: 'U+0370-03FF',
  };
}

/** For the cjk, arabic and comics blocks, which add their own files: the
 *  faces of `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.
 *  The files are added once all have loaded, in the order asked (latin, then
 *  latin-ext, then greek), whatever order they arrive in: the last one added
 *  wins a character two files hold. Resolves to the number of faces added. */
async function loadFonts(faces, text = '', { optional = false } = {}) {
  kitStatus('Loading fonts…');
  const ranges = kitRanges();
  const jobs = [];
  for (const [family, specs] of Object.entries(faces)) {
    const id = fontsourceId(family);
    const todo = [...new Set(specs)].map((spec) => [parseInt(spec, 10), spec.endsWith('i') ? 'italic' : 'normal'])
      .filter(([weight, style]) => !hasFace(family, weight, style)); // before any await
    const at = fontsourceAt(id);
    const meta = optional || /[^\0-ÿ]/u.test(text) ? await fontsourceMeta(family) : null;
    const subsets = ['latin', ...kitSubsetsFor(text, meta)];
    for (const [weight, style] of todo) {
      if (optional && !(meta?.weights.includes(weight) && meta.styles.includes(style))) continue;
      for (const subset of subsets) {
        const url = `${await at}files/${id}-${subset}-${weight}-${style}.woff2`;
        const face = new FontFace(family, `url(${url}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: ranges[subset] });
        jobs.push(face.load().catch(() => {
          if (subset === 'latin' && !optional) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
        }));
      }
    }
  }
  const ready = await Promise.all(jobs).catch((error) => { kitFail(error); throw error; });
  return ready.filter((face) => face && document.fonts.add(face)).length;
}

/** A loaded FontFace covers this 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, '-'); }

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

/** The family's Fontsource metadata (weights, styles, subsets), or null. */
function fontsourceMeta(family) {
  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 v2 ── the same in every recipe · postext.dev/cookbook
/** The pages as spreads on a dark desk, page 1 alone, then verso | recto,
 *  each painted when it scrolls near. Other options go to renderPageToCanvas. */
function showPages(docs, { title, width = 460, ...render } = {}) {
  const root = viewer(title);
  const pages = [docs].flat().flatMap((doc) =>
    doc.pages.map((page) => ({ doc, page, n: (doc.pageIndexOffset ?? 0) + page.index })));
  const spreads = [];
  let verso = null;
  for (const p of pages) {
    if (p.n % 2 === 1) { if (verso) spreads.push([verso, null]); verso = p; }
    else { spreads.push([verso, p]); verso = null; }
  }
  if (verso) spreads.push([verso, null]);
  const density = Math.min(window.devicePixelRatio || 1, 2);
  showPages.painter?.disconnect();
  const painter = new IntersectionObserver((entries) => {
    for (const { isIntersecting, target } of entries) {
      if (!isIntersecting) continue;
      painter.unobserve(target);
      const { doc, page } = target.postext;
      renderPageToCanvas(page, doc, target, { ...render, scale: (width * density) / page.width });
    }
  }, { rootMargin: '800px' });
  showPages.painter = painter;
  root.replaceChildren(...spreads.map((pair) => {
    const spread = document.createElement('div');
    spread.className = 'pt-spread';
    for (const p of pair) {
      const figure = document.createElement('figure');
      if (p) {
        const label = p.page.pageLabel || String(p.n + 1);
        const canvas = document.createElement('canvas');
        canvas.postext = p;
        canvas.style.aspectRatio = `${p.page.width} / ${p.page.height}`;
        canvas.setAttribute('role', 'img');
        canvas.setAttribute('aria-label', `Page ${label}`);
        const folio = document.createElement('figcaption');
        folio.textContent = label;
        figure.append(canvas, folio);
        painter.observe(canvas);
      } else figure.className = 'pt-blank';
      spread.append(figure);
    }
    return spread;
  }));
  kitStatus(`${pages.length} ${pages.length === 1 ? 'page' : 'pages'}`);
  document.documentElement.dataset.postext = 'ready';
  return pages.length;
}

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

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

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

// ─── Kit · images v3 ── recipes with pictures · postext.dev/cookbook
/** Registers a photo or PNG for the canvas and keeps its bytes for the PDF.
 *  fetch → ImageBitmap never taints the canvas (a plain cross-origin <img> would). */
async function loadImage(fileId, url) {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`Image not found (${res.status}): ${url}`);
  const bytes = new Uint8Array(await res.arrayBuffer());
  registerResourceImage(fileId, await createImageBitmap(new Blob([bytes])));
  (loadImage.bytes ??= new Map()).set(fileId, bytes);
}

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

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

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

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

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