Firmament Sans and scholarly typography

The primary Latin and Cyrillic reading font is Firmament Sans, Wheel of Heaven’s scholarly extension of Jost. Bifrost selects all four static styles: regular, italic, bold, and bold italic. The website supplies the self-hosted files at static/fonts/vendor/firmament-sans/0.1/FirmamentSans-*.woff2. The regular face is preloaded; other styles load when used.

Project and design direction#

Firmament began with a reading problem: scholarly Latin characters in the main site’s Jost subset fell back to visibly different typefaces inside otherwise continuous words. The project preserves Jost’s geometric character while adding the distinctions that etymology and transliteration need. Jost is credited to Owen Earl / indestructible type; Firmament is an independently named derivative under the SIL Open Font License.

The public story connects the clarity of 1920s German design with the transmission of knowledge into a future society. Bauhaus, New Typography, and New Objectivity provide three distinct points of reference: practical design, the organisation of information, and attention to the subject. These are Firmament’s contemporary influences, not a claim that the Bauhaus designed Jost or that the movements were interchangeable. Jost’s immediate reference is the spirit of Futura.

The guiding principle is form follows function: make inherited knowledge readable, preserve meaningful distinctions, and leave tools that the next generation can inspect and improve. The maxim predates the Bauhaus; the public design story links the historical sources and separates their history from our interpretation. The Wheel of Heaven wink is: our feet on the baseline and our eyes on the stars.

Repositories and responsibilities#

The font and showcase repositories both link to https://firmament.wheelofheaven.world/ as their public homepage. Their descriptions, topics, and READMEs describe the scholarly extension and modernist design story. Changing the specimen alone does not update the main site’s pinned fonts or Bifrost dependency.

Showcase and hosting#

The one-page specimen includes an editable typesetter, four-style family proofs, letterform anatomy, Jost comparison, searchable character inventory, display and paragraph specimens, multilingual proofs, numbers and signs, design story, release limitations, and licensed downloads. It is Zola 0.22.1 with self-hosted fonts and small dependency-free JavaScript.

Cloudflare Pages builds the showcase repository’s main branch with zola build, publishes public, and uses ZOLA_VERSION=0.22.1. The custom domain is firmament.wheelofheaven.world. Hosting was configured through the Cloudflare dashboard; there is no separate Worker application. Run mise run build and mise run check in the showcase repository before publishing changes.

Brand assets and README screenshots#

Both repositories carry the same self-contained assets under docs/images/:

• brandmark.svg: Firmament Italic’s lowercase f with a rust-coloured dot.
• brandtype.svg: Firmament. drawn from the actual Regular outlines, with a rust full stop.
• showcase.jpg, typesetter.jpg, and characters.jpg: live Chrome viewport captures, with capture date and context recorded in docs/images/README.md.

The palette is warm paper #f1f0e9, forest #26372f, and rust #a74732. SVG outlines make the README identity independent of fonts installed on the viewer’s device. The canonical renderer is scripts/render-brand.py in the showcase repository; it uses FontTools and HarfBuzz. Run it when the identity or font release changes, then copy the reviewed assets to the font repository. Keep both READMEs’ image links and capture notes aligned. Refresh screenshots from the working site when its design changes.

Site code and original prose are CC0-1.0. Bundled fonts and derivative outlines retain the OFL; the site’s CC0 license does not replace it. Preserve authorship, licenses, and provenance when copying assets.

Coverage and deployment#

Each 0.1 style contains 584 Unicode mappings, including 60 additions to full upstream Jost. Alongside macrons and carons (ā ē ī ō ū š), Firmament adds scholarly forms such as ḥ ṣ ṭ ḫ ṛ ḇ ṯ, half-ring letters ʾ ʿ, schwa ə Ə, and four combining marks below. It preserves Jost’s existing Latin and Cyrillic outlines and layout.

CSS uses the deployed files directly without a local() override, so installed fonts cannot silently change coverage. The vendor directory includes the Open Font License, pinned build provenance, and SHA-256 checksums. Versioned paths respect the CDN’s immutable font cache: future releases need a new directory, matching Bifrost declarations/preload, and an updated service-worker precache. The website’s service worker uses cache version v22 for this migration. Bifrost also adds fonts=firmament-0.1 to its stylesheet URLs: a pre-deployment preview had requested the new CSS hash while production still served the old sheet, so the CDN cached Jost under that URL. The explicit release key bypasses that entry. Keep preview base URLs local and advance this key when publishing a new font release. Older Jost files remain available for cached stylesheets.

Review and maintenance#

Firmament Sans 0.1 remains an optical-review pilot. Deployment does not imply complete scholarly or language coverage. Remaining work includes broader IPA and Latin coverage, optical spacing and stacked accents, general mark-to-mark attachment, and variable-font masters. The specimen provides four-style proofs and an interactive character inventory.

The fork contains a corpus inventory with Unicode names, occurrence counts, example paths, and coverage comparisons. Counts describe published Markdown source and library JSON strings across all locales; they are not measurements of browser fallback. Library quotations and original scripts often use other font stacks. Draft Markdown and library review/curation/audio directories are excluded.

Run mise run audit in the font repository to refresh the inventory against a sibling website checkout. Run mise run build and mise run check to build and validate all four static styles. The shaping checks compare precomposed and decomposed forms and verify that ordinary upstream Latin and Cyrillic text retains its shaping.

Source scripts and typography roles#

This extension addresses Latin transliteration within prose. Greek, cuneiform, and East Asian writing keep their script-specific fonts and the existing body/display/citation/metadata roles. An unsupported character in a heading or quotation needs investigation of that element’s font stack; changing the body family alone does not change Space Grotesk or IBM Plex Serif.

See the script-expansion study for proposed Greek, Hebrew, Arabic, cuneiform, and CJK development. These are not new glyph repertoires in the deployed 0.1 fonts.

Hebrew: locale companion versus citation serif#

Hebrew is served by two faces with two jobs, selected by the cascade in sass/base/_base.scss:

Arabic: interface face and reading face#

Arabic had no web font on the main site until 25 October 2026; readers saw whatever their operating system supplied. Two companions from the proof now cover it, split by job the way Hebrew is:

Both @font-face rules are bounded by unicode-range to the Arabic blocks, so the files load only on pages with Arabic and Latin never touches them. Inline Arabic is right-to-left and bidi-isolated like inline Hebrew. Provenance, subset ranges and checksums live in static/fonts/vendor/cairo/ and static/fonts/vendor/noto-naskh-arabic/ in Bifrost. Native-reader review of a full Hidden Words chapter at reading size is still owed.

Japanese body face#

On 25 October 2026 the Japanese body face changed from Zen Kaku Gothic New to Noto Sans JP ($font-family-ja-body; the Google Fonts link in partials/fonts-css.html). In the companion proof Zen Kaku measured 0.84× the contract stem, visibly lighter than Firmament beside it, while Noto Sans JP measured 1.01× and matches the Noto Sans SC/TC/KR siblings in weight and rhythm. M PLUS 1p stays the Japanese display face.

Every CJK body stack ($font-family-ja-body, -zh-body, -zh-hant-body, -ko-body) now starts with Firmament Sans. Firmament has no CJK glyphs, so kana, kanji, hanzi and hangul fall through to the regional face, while Latin and Cyrillic — navigation labels, brand words, transliterations, the “Русский” entry in the language menu — stay in the same face as on every other page. Before this, the regional face supplied them, and Noto Sans JP’s full-width Cyrillic made “Русский” render wide and wrap in the switcher on Japanese pages (found and fixed on 25 October 2026).

Before this split (24 October 2026) :lang(he) set the citation serif directly on every element of the Hebrew locale. That out-specified the plain-element heading rules and lost to component class selectors, so the locale had no body/display layering and component headings fell to system Hebrew fonts. The @font-face for Miriam Libre is bounded by unicode-range to U+0590–05FF, U+FB1D–FB4F, U+200C–2010, U+20AA and U+25CC, so Latin words, digits and punctuation inside Hebrew pages still come from Firmament Sans and Space Grotesk, and the file is never fetched on pages without Hebrew. It is preloaded only when detected_lang == "he" (partials/fonts-css.html). Provenance, subset ranges and the checksum live in static/fonts/vendor/miriam-libre/ in Bifrost. Miriam Libre’s heaviest instance (700) measures 120 ‰, lighter than Firmament Bold’s 152 ‰; Hebrew headings therefore read slightly lighter than their Latin counterparts, which was judged acceptable for a companion and is recorded in the proof.

Code face: iA Writer Mono S#

The theme’s “tech” voice ($font-family-tech, used for labels, bylines and metadata) is iA Writer Quattro S, a duospace in which wide letters take one and a half columns. For text that is code proper, listings and BibTeX, that drift shows. Since 2026-10-25 Bifrost vendors iA Writer Mono S 2.000 (Regular and Bold, SIL OFL, from the upstream iaolo/iA-Fonts repository, every glyph 600/1000 em) at static/fonts/vendor/ia-writer-mono/ and exposes it as $font-family-code, falling back through the Quattro stack. The BibTeX panel of “Cite this page” uses it; site code blocks still set in Quattro and can move to the same token.

Multiscript direction#

A coordinated family should respect each script’s own reading conventions. The following is a development proposal, not coverage claimed by Firmament 0.1:

The full feasibility study contains corpus evidence, candidate families, relative effort, and release gates. Its counts inventory source strings, not actual browser fallback or a complete target repertoire. Add script fonts on demand. Do not silently merge or rename another family’s outlines.

The companion proof and the metric contract#

The study’s first step, a companion proof page, is published at https://firmament.wheelofheaven.world/companions/ and generated by scripts/companions.py in the showcase repository from a pinned google/fonts commit. It defines the metric contract that “harmonious with Firmament” means in numbers, read from the 0.1 outlines:

A companion fits when its stem and colour are within a tenth of the contract at the same nominal weight, its working letter height sits between x-height and cap height, and its marks and joins survive HarfBuzz shaping. Futura’s geometry does not travel between scripts; the measurements do. Outcomes so far: Miriam Libre adopted for the Hebrew locale (above); Cairo and Noto Naskh Arabic adopted for Arabic (above); the Japanese body face moved to Noto Sans JP; no open Greek fits, which is the argument for drawing Firmament Greek (brief in firmament-sans/scholar/greek/); cuneiform and the other CJK pairings keep their current faces, now recorded with measurements as pairing specifications.

Publishing the next font release#

1. In firmament-sans, follow the pinned tooling in mise.toml: mise run setup, mise run build, and mise run check. Refresh the corpus audit when relevant. Review regular, italic, bold, and bold italic at actual reading sizes.
2. In the showcase, run scripts/sync-fonts.py against the sibling font checkout. Review the generated character inventory, statistics, licenses, ZIP README, and versioned download names; regenerate social and brand artwork if affected.
3. Copy the reviewed WOFF2 files into a new version directory in the main website, with the exact source commit, OFL, and updated checksums. Avoid replacing bytes behind an existing immutable URL.
4. Update Bifrost’s sass/base/_fonts.scss, sass/base/_typography.scss when the family changes, and templates/partials/fonts-css.html. Update the site’s static/sw.js precache and increment its cache version.
5. Build the consuming website and inspect desktop/mobile prose, emphasis, scholarly marks, Cyrillic, and source-script companions. Check both main.css and critical.css; previews must load local CSS rather than the production URLs.
6. Merge the theme first, then advance the website’s theme pin alongside its font assets. Publish the updated documentation and showcase as needed.
7. Verify the production deployment, actual font URLs, checksums, computed body stack, and preload. A merged PR alone does not prove the new font is live.

Where Firmament is adopted#

Deliberately unchanged: the narrative map poster (its Latin labels share Jost’s outlines, and the served SVG is text-to-path), the EPUB stylesheet (generic families by design, so e-readers keep their own font preferences), and the video and brand renderers, which use Space Grotesk, the display face.

The initial main-site adoption is recorded in website PR #28, Bifrost PR #3, and documentation PR #3. All four deployed 0.1 files passed coverage, canonical-shaping, and upstream-regression checks; the main site built 10,999 pages and was checked in desktop and 390px mobile previews.