Póster científico en una sola página

// ═══ Postext Cookbook · Nº 059 · Research poster on one big page ══════════════════
// https://postext.dev/en/cookbook/research-poster
// Code: MIT · Text and data: original, synthetic (CC BY 4.0) · Figures: generated in code
// Fonts: Rethink Sans, Bitter, Saira Condensed (SIL OFL 1.1) · Needs postext ≥ 1.4.1
import {
  buildDocument, renderPage, renderPageToCanvas, clearMeasurementCache, registerResourceImage,
  defaultResourceTypes,
} from 'https://esm.sh/postext';

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

// ─── 1 · Design ─────────────────────────────────────────────────────────────
// #region palette: six colours for the poster, four for the heat map's key
const palette = {
  ink: '#102a2c', // text: a green-black
  paper: '#f7faf7', // the sheet, and type on the band
  canopy: '#2e7d4f', // the band, the stripes and titles of five panels, the tree crowns
  tint: '#e6f2ea', // the keyword strip, the park on the plan, lines of type on the band
  rule: '#bcd2c4', // buildings on the plan, the chart's grid
  muted: '#587068', // the notes under the figures, the axis titles inside them
  // The key of Figure 2, the air against the street mean at the same hour. The heat map's
  // cells and the :swatch runs of its key read the same four entries.
  cool: '#3b82c4', // −1.5 °C or less
  mist: '#a9c9e6', // −1.5 to 0 °C
  blush: '#f2b492', // 0 to +1.5 °C
  heat: '#d9572b', // +1.5 °C or more; also −4.2 °C, the Results panel, the loggers, the sun
};
// 1.4.1 designs paint the hex and ignore the paletteId (gotcha: palette-skips-designs).
const col = (id) => ({ hex: palette[id], model: 'hex', paletteId: id });
const colorPalette = [ // defaults link to 'main-color': point it at the canopy green
  ...Object.entries(palette).map(([id, hex]) => ({ id, name: id, value: { hex, model: 'hex' } })),
  { id: 'main-color', name: 'canopy (defaults)', value: { hex: palette.canopy, model: 'hex' } },
];
// #endregion

// #region sheet: one 600 × 800 mm page, laid out at 72 dpi
const SHEET = { width: 600, height: 800, margin: 25 }; // mm: a portrait board, 25 mm all round
const GAP = 12; // mm between the two body columns and between the three panel columns
// The summary's leading is the page's baseline grid: 56 lines fill the 750 mm between the
// margins, so a box floated to the foot of the page ends on the bottom margin.
const LEAD = (((SHEET.height - 2 * SHEET.margin) / 25.4) * 72) / 56; // 37.96 pt
const page = { width: mm(SHEET.width), height: mm(SHEET.height),
  // At 72 dpi a point is a pixel: the page is 1,701 × 2,268 px. The default 300 dpi would give
  // 7,087 × 9,449 px (268 MB of canvas) for the same line breaks.
  dpi: 72, backgroundColor: col('paper'),
  margins: { top: mm(SHEET.margin), bottom: mm(SHEET.margin), left: mm(SHEET.margin),
    right: mm(SHEET.margin) } }; // one sheet, nothing to mirror
// #endregion
const at = (to, edge, x = 0, y = 0) => ({ anchor: { to, edge }, offset: { x: mm(x), y: mm(y) } });

// #region band: the title band is the H1's design, filled from its attributes
const BAND = 158; // mm from the top edge to the foot of the green field
const type = (id, content, family, size, look, placement) => ({ kind: 'text', id, content,
  fontFamily: family, fontSize: pt(size), color: col('paper'), align: 'left',
  overflow: 'wrap', // not an ellipsis (gotcha: overflow-ellipsis-default)
  lineHeight: 1.2, // a multiple of the size (gotcha: design-lineheight-multiple)
  ...look, placement });
const band = { enabled: true,
  // The field ends 133 mm under the top margin; eleven grid lines (147 mm) start the summary
  // 14 mm below it.
  minHeight: pt(11 * LEAD),
  slot: { elements: [
    { kind: 'box', id: 'field', style: { backgroundColor: col('canopy') },
      placement: { ...at('page', 'top-left'), size: { width: 'fill', height: mm(BAND) } } },
    type('meeting', '{attr.meeting}', 'Saira Condensed', 22, { fontWeight: 600,
      textTransform: 'uppercase', letterSpacing: pt(3.5), color: col('tint') },
    { ...at('page', 'top-left', SHEET.margin, 18), size: { width: mm(420) } }),
    type('title', '{titleText}', 'Bitter', 110, { fontWeight: 800, lineHeight: 1 },
      { ...at('#meeting', 'below', 0, 7), size: { width: mm(380) } }),
    type('authors', '{attr.authors}', 'Rethink Sans', 30, { fontWeight: 700 },
      { ...at('#title', 'below', 0, 7), size: { width: 'fill' } }),
    // Design text prints plain text, so the affiliation marks are the characters ¹ ² ³
    // (gotcha: design-text-no-inline-marks).
    type('affiliations', '{attr.affiliations}', 'Rethink Sans', 21, { color: col('tint') },
      { ...at('#authors', 'below', 0, 2), size: { width: 'fill' } }),
    type('number', '{attr.poster}', 'Saira Condensed', 30, { fontWeight: 700,
      color: col('canopy'), box: { backgroundColor: col('paper'),
        padding: { top: mm(1.5), right: mm(4), bottom: mm(1), left: mm(4) } } },
    at('page', 'top-right', -SHEET.margin, 15)),
    // The School of Geography's mark, drawn in code.
    { kind: 'image', id: 'mark', resourceId: 'mark',
      placement: { ...at('page', 'top-right', -SHEET.margin, 38), size: { width: mm(92) } } },
  ] } };
// #endregion

// #region answer: three columns of panels inside one box across the page
// The body text runs in two columns. Three columns exist only inside a box: a :::columns
// group in a callout, and span="page" lays that callout across both body columns.
//   :::callout{type="grid" span="page"}       ← one frameless box across the page
//   :::columns{count=3 breaks="3,4"}          ← panel 3 opens column 2, panel 4 column 3
//   :::callout{type="panel" title="Introduction"}   ← each panel is a box nested in it
//   …
//   :::                                       ← closes the panel; then the other panels
//   :::                                       ← closes the columns group
//   :::                                       ← closes the grid (gotcha: callout-columns)
const grid = { id: 'grid', backgroundEnabled: false, // no fill or frame; each panel has a stripe
  padding: { top: pt(0), right: pt(0), bottom: pt(0), left: pt(0) },
  columnGap: mm(GAP) };
// A nested box takes the width of its column and ignores span and placement (gotcha:
// nested-callout-limits). Its one device is a 6 pt stripe along the top.
const panel = { id: 'panel', backgroundEnabled: false,
  stripe: { enabled: true, side: 'top', width: pt(6), color: col('canopy') },
  padding: { top: mm(5), right: pt(0), bottom: pt(0), left: pt(0) },
  titleStyle: { fontFamily: 'Saira Condensed', fontSize: pt(40), fontWeight: 700,
    textTransform: 'uppercase', letterSpacing: pt(4), color: col('canopy'), gap: mm(4) },
  body: { fontSize: pt(22), lineHeight: pt(30) }, // the rest follows bodyText
  marginTop: mm(18) };
const results = { ...panel, id: 'results', // the finding: the same panel, striped in heat
  stripe: { ...panel.stripe, color: col('heat') },
  titleStyle: { ...panel.titleStyle, color: col('heat') } };
// #endregion

// #region type: paragraph styles for the figure, the references and the key; the foot strip
const paragraphStyles = [
  // Paragraph styles apply inside boxes, nested ones included. They have no weight in
  // 1.4.1, so the figure is written **bold**: that sets it in Bitter 700 and in boldColor.
  { id: 'stat', fontFamily: 'Bitter', fontSize: pt(150), lineHeight: pt(130),
    boldColor: col('heat') },
  { id: 'refs', fontSize: pt(19), lineHeight: pt(26), hangingIndent: mm(9), spaceBetween: pt(8) },
  { id: 'key', fontSize: pt(19), lineHeight: pt(28) }, // the key of Figure 2
];
const chipStyles = [{ id: 'keyword', background: col('paper'), borderColor: col('canopy'),
  borderWidth: pt(1.5), borderRadius: em(1), paddingX: em(0.55), paddingY: em(0.14),
  color: col('canopy'), bold: true, gap: em(0.35) }];
const strip = { id: 'strip', background: col('tint'), // one device: a tint
  padding: { top: mm(4), right: mm(8), bottom: mm(4), left: mm(8) }, columnGap: mm(GAP),
  body: { fontSize: pt(18), lineHeight: pt(24) } };
// #endregion

const config = () => ({ // a factory: the engine caches resolved configs per object
  colorPalette, page,
  layout: { layoutType: 'double', gutterWidth: mm(GAP) },
  // The summary's type; the boxes take the family, the rag and the paragraph spacing from it.
  bodyText: { fontFamily: 'Rethink Sans', fontSize: pt(28), lineHeight: pt(LEAD),
    color: col('ink'), textAlign: 'left', firstLineIndent: pt(0), paragraphSpacing: true,
    // Bold in the boxes and the :ref labels copy boldColor, and the italics of the references'
    // paragraph style take italicColor (gotcha: style-italic-colour); both are green otherwise.
    boldColor: col('ink'), italicColor: col('ink') },
  // The band draws the title, but 1.4.1 still measures the H1's own text: in Bitter, a face
  // already loaded, instead of the default Open Sans 700.
  headings: { fontFamily: 'Bitter', levels: [
    // Restated (gotcha: headings-drop-h1-break): a second poster in the file starts a page.
    { level: 1, span: 'page', breakBefore: { enabled: true, parity: 'any' },
      marginBottom: pt(0), advancedDesign: band }] },
  calloutStyles: [grid, panel, results, strip],
  paragraphStyles, chipStyles, resourceTypes,
  captionStyle: { fontSize: pt(19), labelColor: col('canopy'), gap: mm(3),
    note: { fontSize: pt(17), color: col('muted') } },
  header: { elements: [] }, footer: { elements: [] }, // a poster has no running heads
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
// #region figures: three drawings set inside their panels, numbered 1, 2, 3
// "Figure 1", not "Figure 1.1": the poster has no chapters.
const figureType = { ...defaultResourceTypes(LANG)[0], numberingTemplate: '{n}' };
const resourceTypes = [figureType];
const figure = (id, [width, height], caption, altText) => ({ id, typeId: figureType.id,
  kind: 'svg', svg: { fileId: `${id}.svg`, width: width * 10, height: height * 10 },
  placement: { position: 'here' }, // stays in its panel, where ::resource puts it; else floats
  caption, altText, note: t({ en: 'Synthetic data, generated for this poster.',
    es: 'Datos sintéticos, generados para este póster.' }), createdAt: 0, updatedAt: 0 });
// #endregion
const markdown = String.raw`---
Muestra en Markdown · 95 líneas · content.es.md
title: "Arbolado viario y calor en la acera"
author: "Nuria Castellví, Tomás Iribarren, Helena Quiroga"
---

# Arbolado viario y calor en la acera {meeting="IV Encuentro sobre Calle y Clima · Almedo, 14–16 de octubre de 2026" poster="P-47" authors="Nuria Castellví¹ · Tomás Iribarren² · Helena Quiroga¹,³" affiliations="¹ Departamento de Geografía, Universidad de Almedo     ² Servicio de Arbolado Viario, Ayuntamiento de Almedo     ³ Observatorio del Clima Urbano"}

**Resumen.** Medimos el aire a la altura de la cabeza en las dieciséis manzanas de la avenida de la Estación, y fotografiamos sus aceras con una cámara térmica, en las catorce tardes de 2025 que pasaron de 30 °C. De 13:00 a 17:00, bajo un 70 % de copa o más, el aire estuvo 4,2 °C más fresco que en el tramo comercial, casi sin árboles, y el pavimento 15 °C más fresco. El Ayuntamiento decidirá así cuáles de sus 212 alcorques vacíos plantará primero.

:::callout{type="grid" span="page"}
:::columns{count=3 breaks="3,4"}
:::callout{type="panel" title="Introducción"}
En julio, a media tarde, una acera de hormigón al sol puede pasar de 50 °C, y el aire que tiene encima se calienta con ella. Las copas detienen el sol antes de que llegue al pavimento [1, 2].

Casi todos los estudios comparan un parque con las calles que lo rodean [3]. La avenida pasa del pavimento desnudo a copas que se tocan sobre la calzada, así que cada manzana se compara con sus vecinas la misma tarde.

**Pregunta.** ¿Cuánto refresca cada escalón de copa y a qué horas?
:::
:::callout{type="panel" title="Métodos"}
La avenida (:ref{id="plan"}) va del parque de la Alameda a la estación de autobuses: 800 m en dieciséis manzanas de 50 m. Tiene plátanos de 1908 junto al parque y tilos en las manzanas 13 a 15; el tramo comercial casi no tiene árboles.

::resource{id="plan"}

- **Aire.** Un registrador por manzana, a 1,5 m en una farola, con una lectura cada 5 minutos.
- **Pavimento.** Una cámara térmica recorrió las dos aceras a las 15:00.
- **Copa.** La parte de acera bajo las copas, trazada sobre fotografías aéreas.

El aire se da respecto a la media de la calle a esa hora, lo que descuenta el tiempo del día.
:::
:::callout{type="results" title="Resultados"}
:::paragraphs{style="stat"}
**−4,2 °C**
:::

**Aire a 1,5 m, de 13:00 a 17:00, con un 70 % de copa o más frente a menos del 10 %.**

Plátanos y tilos refrescan sus manzanas toda la tarde; el tramo comercial sigue caliente (:ref{id="heat"}).

:::columns{count=2 breaks="3"}
:::paragraphs{style="key"}
:swatch{color="cool"} −1,5 °C o menos

:swatch{color="mist"} de −1,5 a 0 °C

:swatch{color="blush"} de 0 a +1,5 °C

:swatch{color="heat"} +1,5 °C o más
:::
:::

:::space{lines=0.33}

::resource{id="heat"}

A las 15:00 el pavimento (:ref{id="bars"}) daba 48,4 °C en el tramo comercial y 33,4 °C bajo copa densa.

::resource{id="bars"}
:::
:::callout{type="panel" title="Conclusiones"}
Cada 10 % de copa restó 2,1 °C al pavimento a las 15:00 y 0,6 °C al aire de 13:00 a 17:00.

El efecto es mayor por la tarde, cuando se vuelve a casa a pie. Antes de las 09:00 y tras las 19:00 la diferencia no llega a 1,5 °C, y a las 20:00 la sombra está 0,4 °C más caliente.

Los 200 m del tramo comercial son los más calurosos de la calle. Si la relación se mantiene, su pavimento pasará de 48,4 °C a unos 39 °C a las 15:00 cuando las copas cubran media acera.
:::
:::callout{type="panel" title="Plan de plantación"}
El Ayuntamiento arbolará primero las manzanas más calurosas, empezando por el tramo comercial. Repetiremos la campaña en 2028.

1. **Manzanas 7–10**: 38 árboles en 2026.
2. **Manzana 16**, la estación: 9 árboles en 2027.
3. **Manzanas 11–12**: 21 árboles en 2027.
4. **Manzanas 5–6**: 12 árboles en 2028.
:::
:::callout{type="panel" title="Referencias"}
:::paragraphs{style="refs"}
[1] Oke, T.R. (1982). The energetic basis of the urban heat island. *Quarterly Journal of the Royal Meteorological Society*, 108, 1–24.

[2] Armson, D., Stringer, P. y Ennos, A.R. (2012). The effect of tree shade and grass on surface and globe temperatures in an urban area. *Urban Forestry & Urban Greening*, 11, 245–255.

[3] Bowler, D.E., Buyung-Ali, L., Knight, T.M. y Pullin, A.S. (2010). Urban greening to cool towns and cities: a systematic review of the empirical evidence. *Landscape and Urban Planning*, 97, 147–155.
:::

:::space{lines=0.75}

Gracias al alumbrado público de Almedo por las farolas y a Inês Barros por sus catorce vueltas con la cámara térmica.
:::
:::
:::

:::callout{type="strip" span="page" placement="bottom"}
:::columns{count=2 breaks="2"}
**Palabras clave** :chip[arbolado viario]{style="keyword"} :chip[calor urbano]{style="keyword"} :chip[cobertura de copa]{style="keyword"} :chip[termografía]{style="keyword"}

Calle, autores y datos inventados para el Recetario de Postext. Compuesto en Rethink Sans, Bitter y Saira Condensed (SIL OFL). Texto y figuras CC BY 4.0.
:::
:::
`; // content.<lang>.md, inlined by the Cookbook

// #region art: the synthetic survey, the plan, the heat map, the bars and the mark
function mulberry32(seed) { // a seeded PRNG: the same survey on every run
  return () => {
    seed = (seed + 0x6d2b79f5) | 0;
    let r = Math.imul(seed ^ (seed >>> 15), 1 | seed);
    r = (r + Math.imul(r ^ (r >>> 7), 61 | r)) ^ r;
    return ((r ^ (r >>> 14)) >>> 0) / 4294967296;
  };
}
// Sixteen 50 m blocks, west to east: the park's planes, houses, the Parade, new planting,
// old limes and the bus station. Canopy is the share of sidewalk under crowns, in %.
const CANOPY = [84, 78, 72, 66, 45, 31, 4, 0, 6, 9, 18, 27, 58, 74, 71, 12];
const HOURS = [8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20];
// How much of the shade shows in the air at each hour: most at 14:00–15:00, reversed by 20:00.
const SUN = [0.3, 0.4, 0.55, 0.7, 0.85, 0.95, 1, 1, 0.95, 0.8, 0.55, 0.25, -0.1];
const SURVEY = (() => { // air: °C against the street mean at the hour; surface: °C at 15:00
  const rand = mulberry32(25);
  // Six uniforms summed and scaled: close enough to a normal draw with a mean of 0 and an SD of 1.
  const noise = () => [...Array(6)].reduce((sum) => sum + rand(), -3) / Math.sqrt(0.5);
  const mean = CANOPY.reduce((a, b) => a + b) / CANOPY.length;
  return CANOPY.map((c) => ({ canopy: c,
    air: SUN.map((w) => (w * 6.2 * (mean - c)) / 100 + 0.22 * noise()),
    surface: 49.2 - 0.205 * c + 0.7 * noise() }));
})();
const CLASSES = [[0, 10], [10, 30], [30, 50], [50, 70], [70, 101]]; // canopy classes, %
const avg = (values) => values.reduce((a, b) => a + b, 0) / values.length;
const surfaceOf = ([lo, hi]) => avg(SURVEY.filter((b) => b.canopy >= lo && b.canopy < hi)
  .map((b) => b.surface));
const classOf = (v) => (v <= -1.5 ? 'cool' : v < 0 ? 'mist' : v < 1.5 ? 'blush' : 'heat');
const f = (v) => +v.toFixed(2);
const X0 = 12; // mm: the left gutter of the plan and the heat map
const CELL = (175 - X0) / CANOPY.length; // mm per block: the plan and Figure 2 share columns
const cx = (i) => f(X0 + (i + 0.5) * CELL);
const label = (x, y, text, size, fill = palette.ink, anchor = 'middle', extra = '') =>
  `<text x="${f(x)}" y="${f(y)}" font-size="${size}" text-anchor="${anchor}" fill="${fill}"`
  + `${extra}>${text}</text>`;
const svg = (w, h, body, face) => `<svg xmlns="http://www.w3.org/2000/svg" width="${w * 10}" `
  + `height="${h * 10}" viewBox="0 0 ${w} ${h}">${face}${body}</svg>`;
// An SVG drawn as an image cannot use the page's web fonts (gotcha: svg-no-webfonts), so
// each drawing carries its label face inline, as a data URL of the Fontsource file.
async function inlineFace(family, weight) {
  const id = family.toLowerCase().replace(/\s+/g, '-');
  const url = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-${weight}`
    + '-normal.woff2';
  const bytes = new Uint8Array(await (await fetch(url)).arrayBuffer());
  let bin = '';
  for (const b of bytes) bin += String.fromCharCode(b);
  return `<style>@font-face{font-family:F;src:url(data:font/woff2;base64,${btoa(bin)}) `
    + `format('woff2')}text{font-family:F}</style>`;
}
const channel = (hex, i) => parseInt(hex.slice(i, i + 2), 16);
const mix = (a, b, k) => `#${[1, 3, 5].map((i) => Math.round(channel(a, i) * (1 - k)
  + channel(b, i) * k).toString(16).padStart(2, '0')).join('')}`; // a towards b by k

const FIG = { plan: [175, 62], heat: [175, 126], bars: [175, 83] }; // mm, at column width
const LABEL = 5.4; // mm: figure labels, about 15 pt

function planSvg(face) { // Figure 1: a schematic plan, west on the left
  const rand = mulberry32(1908); // seeded with the year the planes were planted
  const [W, H] = FIG.plan;
  const [NB, NS, ROAD, SS, SB] = [[11, 22], [22, 25], [25, 34], [34, 37], [37, 48]]; // y bands
  const SIDE = [4, 6, 10, 13]; // side streets east of these blocks (block index from 0)
  let out = `<rect x="${X0}" y="${ROAD[0]}" width="${W - X0}" height="${ROAD[1] - ROAD[0]}" `
    + `fill="${mix(palette.paper, palette.ink, 0.16)}"/>`;
  for (let x = X0 + 2; x < W - 2; x += 6) { // the centre line
    out += `<path d="M${f(x)} 29.5h3" stroke="${palette.paper}" stroke-width="0.4"/>`;
  }
  CANOPY.forEach((c, i) => { // the frontages: houses, the park, the shops
    const x = X0 + i * CELL;
    const w = SIDE.includes(i) ? CELL - 3.2 : CELL;
    if (i < 3) {
      out += `<rect x="${f(x)}" y="${NB[0] - 2}" width="${f(w)}" height="${NB[1] - NB[0] + 2}" `
        + `fill="${palette.tint}"/>`;
    } else {
      const fill = i >= 6 && i <= 9 ? mix(palette.rule, palette.ink, 0.3) : palette.rule;
      for (const [y0, y1] of [NB, SB]) {
        const cut = rand() * 0.3 + 0.35;
        out += `<rect x="${f(x + 0.4)}" y="${y0}" width="${f(w * cut - 0.8)}" height="${y1 - y0}"`
          + ` fill="${fill}"/><rect x="${f(x + w * cut + 0.4)}" y="${y0}" `
          + `width="${f(w * (1 - cut) - 0.8)}" height="${y1 - y0}" fill="${fill}"/>`;
      }
    }
  });
  out += `<rect x="${f(X0)}" y="${SB[0]}" width="${f(3 * CELL - 0.8)}" height="${SB[1] - SB[0]}" `
    + `fill="${palette.rule}"/>`; // houses face the park across the road
  CANOPY.forEach((c, i) => { // crowns along both sidewalks, as many as the canopy share
    const n = Math.round((c / 100) * 3.6);
    // Under 14 % the share rounds to no crown: such a block gets one tree on the south side.
    const rows = n > 0 ? [[NS, n], [SS, n]] : c > 0 ? [[SS, 1]] : [];
    for (const [[y0, y1], count] of rows) {
      for (let k = 0; k < count; k++) {
        const x = X0 + i * CELL + ((k + 0.5) / count) * CELL + (rand() - 0.5) * 1.2;
        const r = 2 + (c / 100) * 1.3 + rand() * 0.5; // the old planes have the widest crowns
        out += `<circle cx="${f(x)}" cy="${f((y0 + y1) / 2)}" r="${f(r)}" fill="${palette.canopy}"`
          + ` fill-opacity="0.85" stroke="${palette.paper}" stroke-width="0.3"/>`;
      }
    }
    if (i < 3) { // the park's own trees
      for (let k = 0; k < 4; k++) {
        out += `<circle cx="${f(X0 + i * CELL + 2 + rand() * (CELL - 4))}" `
          + `cy="${f(NB[0] + 1 + rand() * 7)}" r="${f(1.8 + rand())}" fill="${palette.canopy}" `
          + 'fill-opacity="0.55"/>';
      }
    }
  });
  CANOPY.forEach((c, i) => { // the loggers, on the north kerb, one per block
    out += `<circle cx="${cx(i)}" cy="${NS[1]}" r="1.4" fill="${palette.heat}" `
      + `stroke="${palette.ink}" stroke-width="0.35"/>` + label(cx(i), 55, i + 1, LABEL);
  });
  const names = t({ en: ['ASHBY PARK', 'THE PARADE', 'BUS STATION'],
    es: ['PARQUE DE LA ALAMEDA', 'TRAMO COMERCIAL', 'ESTACIÓN DE AUTOBUSES'] });
  const track = ' letter-spacing="0.4"';
  out += label(X0, 6.5, names[0], LABEL - 0.6, palette.canopy, 'start', track)
    + label(X0 + 8 * CELL, 6.5, names[1], LABEL - 0.6, palette.ink, 'middle', track)
    + label(W, 6.5, names[2], LABEL - 0.6, palette.ink, 'end', track);
  // The north arrow in the gutter: a line and a triangle.
  out += `<path d="M5 27V18" stroke="${palette.ink}" stroke-width="0.7"/>`
    + `<path d="M5 13l2.6 5.4h-5.2z" fill="${palette.ink}"/>` + label(5, 34, 'N', LABEL);
  const bar = 2 * CELL; // 100 m: two blocks
  out += `<path d="M${X0} 60.6h${f(bar)}" stroke="${palette.ink}" stroke-width="0.9"/>`
    + label(X0 + bar + 2, 61.8, '100 m', LABEL - 0.6, palette.ink, 'start');
  return svg(W, H, out, face);
}

function heatSvg(face) { // Figure 2: canopy bars over an hour × block heat map
  const [W, H] = FIG.heat;
  const [BASE, TOP, ROW] = [27, 30, 6.2]; // mm: foot of the bars, top of the grid, row height
  let out = '';
  SURVEY.forEach((b, i) => {
    const h = (b.canopy / 100) * 18;
    out += `<rect x="${f(X0 + i * CELL + 1.6)}" y="${f(BASE - h)}" width="${f(CELL - 3.2)}" `
      + `height="${f(h)}" fill="${palette.canopy}"/>`
      + label(cx(i), f(BASE - h - 1.6), b.canopy, LABEL - 0.8);
    b.air.forEach((v, r) => {
      out += `<rect x="${f(X0 + i * CELL + 0.3)}" y="${f(TOP + r * ROW + 0.3)}" `
        + `width="${f(CELL - 0.6)}" height="${f(ROW - 0.6)}" fill="${palette[classOf(v)]}"/>`;
    });
    out += label(cx(i), TOP + HOURS.length * ROW + 6.5, i + 1, LABEL);
  });
  out += `<path d="M${X0} ${BASE + 0.2}H${W}" stroke="${palette.ink}" stroke-width="0.4"/>`
    + label(X0 - 1.5, BASE - 7, '%', LABEL, palette.ink, 'end'); // level with the bars
  HOURS.forEach((hour, r) => {
    if (hour % 2 === 0) {
      out += label(X0 - 1.5, TOP + r * ROW + 5, String(hour).padStart(2, '0'), LABEL,
        palette.ink, 'end');
    }
  });
  const track = ' letter-spacing="0.4"';
  const [west, east, hour] = t({ en: ['WEST', 'EAST', 'HOUR'], es: ['OESTE', 'ESTE', 'HORA'] });
  const mid = f(TOP + (HOURS.length * ROW) / 2); // the hour axis's title runs up the gutter
  out += label(X0, H - 0.5, west, LABEL - 1, palette.muted, 'start', track)
    + label(W, H - 0.5, east, LABEL - 1, palette.muted, 'end', track)
    + label(0, 0, hour, LABEL - 1, palette.muted, 'middle',
      `${track} transform="translate(3.4 ${mid}) rotate(-90)"`);
  return svg(W, H, out, face);
}

function barsSvg(face) { // Figure 3: how much cooler the paving was, by canopy class
  const [W, H] = FIG.bars;
  const [LEFT, ROW, SCALE] = [40, 13, 7.6]; // SCALE: mm per °C
  const names = t({ en: ['under 10 %', '10–30 %', '30–50 %', '50–70 %', '70 % or more'],
    es: ['menos del 10 %', '10–30 %', '30–50 %', '50–70 %', '70 % o más'] });
  const base = surfaceOf(CLASSES[0]); // the paving under 10 % canopy: the zero of the scale
  const num = (v) => t({ en: v.toFixed(1), es: v.toFixed(1).replace('.', ',') });
  const foot = 5 * ROW + 2;
  let out = '';
  for (const step of [5, 10, 15]) {
    out += `<path d="M${LEFT + step * SCALE} 1V${foot}" stroke="${palette.rule}" `
      + 'stroke-width="0.35"/>' + label(LEFT + step * SCALE, foot + 6.5, step, LABEL);
  }
  CLASSES.forEach((cls, i) => {
    const cooler = base - surfaceOf(cls);
    const y = 1 + i * ROW;
    const fill = mix(palette.tint, palette.canopy, 0.3 + 0.7 * (i / 4));
    out += label(LEFT - 3, y + 8.3, names[i], LABEL, palette.ink, 'end');
    if (i === 0) out += label(LEFT + 2, y + 8.3, `${num(base)} °C`, LABEL, palette.muted, 'start');
    else {
      out += `<rect x="${LEFT}" y="${y + 1.2}" width="${f(cooler * SCALE)}" height="${ROW - 2.4}" `
        + `fill="${fill}"/>` + label(LEFT + cooler * SCALE + 2, y + 8.3, num(cooler), LABEL,
        palette.ink, 'start');
    }
  });
  const axis = t({ en: '°C cooler than the blocks under 10 %',
    es: '°C por debajo de las manzanas de menos del 10 %' });
  out += `<path d="M${LEFT} 0V${foot + 1}" stroke="${palette.ink}" stroke-width="0.6"/>`
    + label(LEFT, foot + 6.5, '0', LABEL)
    + label(LEFT + 7.5 * SCALE, foot + 14, axis, LABEL, palette.muted, 'middle');
  return svg(W, H, out, face);
}

function markSvg() { // the School of Geography's mark: a crown shading a street, in a ring
  const shade = mix(palette.canopy, palette.ink, 0.45);
  return svg(10, 10, '<g transform="scale(0.1)">'
    + `<circle cx="50" cy="50" r="46" fill="none" stroke="${palette.paper}" stroke-width="3.2"/>`
    + `<circle cx="70" cy="25" r="8" fill="${palette.heat}"/>` // the sun, behind the crown
    + `<ellipse cx="43" cy="71" rx="23" ry="4.5" fill="${shade}"/>` // its shade on the paving
    + `<rect x="47" y="48" width="6" height="23" fill="${palette.paper}"/>`
    + `<circle cx="50" cy="37" r="17" fill="${palette.paper}"/>`
    + `<circle cx="35" cy="46" r="11" fill="${palette.paper}"/>`
    + `<circle cx="65" cy="46" r="11" fill="${palette.paper}"/>`
    + `<path d="M17 71H83" stroke="${palette.paper}" stroke-width="3.2"/></g>`, '');
}
// #endregion

const resources = [
  figure('plan', FIG.plan, t({
    en: 'Ashby Road, schematic plan: crowns from the canopy survey and the 16 loggers '
      + '(orange). Widths across the street are not to scale.',
    es: 'La avenida en plano esquemático: las copas del inventario de arbolado y los 16 '
      + 'registradores (naranja). Los anchos transversales no están a escala.' }), t({
    en: 'Plan of a straight street in 16 numbered blocks, with a park at the west end, tree '
      + 'crowns along both sidewalks and one tree or none on each of blocks 7 to 10.',
    es: 'Plano de una calle recta en 16 manzanas numeradas, con un parque en el extremo oeste, '
      + 'copas en las dos aceras y un árbol o ninguno en cada una de las manzanas 7 a 10.' })),
  figure('heat', FIG.heat, t({
    en: 'Canopy cover per block (bars, %) and the air at head height against the street mean '
      + 'at the same hour, from 08:00 to 20:00; mean of 14 afternoons.',
    es: 'Copa por manzana (barras, %) y aire a la altura de la cabeza respecto a la media de '
      + 'la calle a esa hora, de 08:00 a 20:00; media de 14 tardes.' }), t({
    en: 'Bar chart of canopy cover for 16 blocks above a grid of coloured cells, hours down '
      + 'and blocks across: blue under the tree-lined blocks in the afternoon, orange along '
      + 'blocks 7 to 10.',
    es: 'Barras de cobertura de copa de 16 manzanas sobre una cuadrícula de celdas de color, '
      + 'horas hacia abajo y manzanas en horizontal: azul bajo las manzanas arboladas por la '
      + 'tarde, naranja en las manzanas 7 a 10.' })),
  figure('bars', FIG.bars, t({
    en: 'The paving at 15:00 by canopy class, as the difference from the blocks under 10 %.',
    es: 'El pavimento a las 15:00 por clase de copa, como diferencia con las manzanas de '
      + 'menos del 10 %.' }), t({
    en: 'Horizontal bars that grow with the canopy class, from 2.7 to 15.0 °C cooler.',
    es: 'Barras horizontales que crecen con la clase de copa, de 2,7 a 15,0 °C menos.' })),
  // Not cited in the text: only the band's design draws it.
  { id: 'mark', typeId: figureType.id, kind: 'svg', svg: { fileId: 'mark.svg', width: 100,
    height: 100 }, altText: t({ en: 'The mark of the School of Geography',
    es: 'La marca del Departamento de Geografía' }), createdAt: 0, updatedAt: 0 },
];

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
const FONTS = { // text, display and label faces, loaded before the build (gotcha: fonts-first)
  'Rethink Sans': ['400', '400i', '700'],
  Bitter: ['400', '700', '800'], // 400: the stat style's base face, which the build measures
  'Saira Condensed': ['600', '700'] };

// ─── 4 · Build & show ───────────────────────────────────────────────────────
await loadFonts(FONTS, markdown);
const face = await inlineFace('Saira Condensed', 600);
await Promise.all([loadSvg('plan.svg', planSvg(face)), loadSvg('heat.svg', heatSvg(face)),
  loadSvg('bars.svg', barsSvg(face)), loadSvg('mark.svg', markSvg())]);
const doc = await buildWithFonts(() => buildDocument({ markdown, resources }, config()), markdown);
showPages(doc, { title: t({ en: 'Research poster', es: 'Póster científico' }) });
// The e-poster: renderPage paints the page at its own size, 1,701 × 2,268 px at 72 dpi.
const png = Object.assign(document.createElement('a'), { download: `${RECIPE}.png`,
  textContent: t({ en: 'E-poster PNG', es: 'PNG del póster digital' }) });
renderPage(doc.pages[0], doc).toBlob((blob) => { png.href = URL.createObjectURL(blob); });
document.getElementById('pt-actions').append(png);

Kit · core, fonts, viewer, images: igual en todas las recetas · 270 líneas
// ─── 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 · 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 ───────────────────────────────────────────────────────────────────────