ZDDC/shared/fonts/README.md

shared/fonts/

Source .woff2 files for the typography baked into every tool. These are the raw font bytes; the actual @font-face declarations live in shared/fonts.css as base64 data URIs so single-file HTML tools render identically offline (file://) and online with no CDN dependency.

Files

• ibm-plex-sans-400.woff2 — UI body text (regular weight)
• ibm-plex-sans-600.woff2 — UI emphasis (semibold)
• source-serif-4-600.woff2 — display/headings (semibold)

Latin subsets only. ~60 KB total raw; ~80 KB once base64-inlined.

Regenerating shared/fonts.css

Run from the repo root:

python3 - <<'PY'
import base64, pathlib
fonts = [
    ('IBM Plex Sans',   400, 'ibm-plex-sans-400.woff2'),
    ('IBM Plex Sans',   600, 'ibm-plex-sans-600.woff2'),
    ('Source Serif 4',  600, 'source-serif-4-600.woff2'),
]
out = pathlib.Path('shared/fonts.css')
lines = ['/* shared/fonts.css — base64-inlined woff2. Generated by',
         ' * shared/fonts/README.md instructions; do NOT edit by hand. */', '']
for family, weight, fn in fonts:
    b64 = base64.b64encode((pathlib.Path('shared/fonts') / fn).read_bytes()).decode('ascii')
    lines += ['@font-face {',
              f"    font-family: '{family}';",
              '    font-style: normal',
              f'    font-weight: {weight};',
              '    font-display: swap;',
              f"    src: url(data:font/woff2;base64,{b64}) format('woff2');",
              '}', '']
out.write_text('\n'.join(lines))
PY

Adding or swapping a font

1. Download the new .woff2 into this directory (latin subset only — keep the bundle small).
2. Update the fonts list in the snippet above to include the new family
   • weight + filename.
3. Re-run the regen snippet.
4. Update --font or --font-display tokens in shared/base.css.
5. ./build and verify every tool's dist/*.html still includes @font-face (three by default).

Sourcing

Originally downloaded from the @fontsource npm packages via jsdelivr:

• IBM Plex Sans 400/600: @fontsource/ibm-plex-sans@5.0.18
• Source Serif 4 600: @fontsource/source-serif-4@5.0.5

Both licenses are SIL Open Font License 1.1. Fontsource bundles only the latin subset by default, which is exactly what we want.