# Fonts

The site's four faces, self-hosted. `src/styles.css` declares them and names
the job each one does; this file is where they came from and what may be done
with them.

Nothing is fetched from a font CDN at runtime. A third party in the critical
path of the first paint is a third party who can take the page down, and the
rest of the site is one S3 bucket behind CloudFront.

## What is here

| Family | Job | Weights | Version |
| --- | --- | --- | --- |
| Chakra Petch | `--font-display`, `--font-labels` | 600, 700 | v13 |
| Barlow Semi Condensed | `--font-text` | 400, 500, 600, 700 | v16 |
| Saira Semi Condensed | `--font-facts` | 400 | v15 |
| Roboto Mono | `--font-data` | 400–700 variable | v31 |

Each file is one weight and one subset: `<family>-<weight>-<subset>.woff2`.
Both `latin` and `latin-ext` are here, carrying the `unicode-range` the Google
Fonts CSS API published with them, so latin-ext is downloaded only when a
handle or a post actually has an accent in it. An English page loads the latin
files and nothing else.

Weights are only the ones the stylesheet asks for, and `scripts/fonts.test.mjs`
checks that in both directions: a file no `@font-face` declares fails, and so
does a rule wanting a weight no face supplies. The second one is the reason the
test exists — a missing weight is synthesised rather than refused, so it renders
as the regular smeared sideways and nothing says so.

Saira is 400 alone because `.fact p` is the only rule that uses it and nothing
in a fact card is bold. Copy that arrives with a `<strong>` in it needs the 600
added here, or it gets a synthesised one.

## Where they came from

`https://fonts.googleapis.com/css2?family=<family>:wght@<weights>&display=swap`,
requested with a browser user agent so the API answers in woff2, then the
`src:` URLs from the `latin` and `latin-ext` blocks fetched as-is. The version
column above is the `vNN` segment of those URLs. To refresh a family, request
it again and compare that segment; the files are unmodified downloads, so
there is nothing local to reapply.

## Licences

All four are under the SIL Open Font License 1.1, whose text is beside them:

- `OFL-Chakra-Petch.txt`
- `OFL-Barlow-Semi-Condensed.txt`
- `OFL-Saira-Semi-Condensed.txt`
- `OFL-Roboto-Mono.txt`

Two consequences worth knowing before touching these files. The OFL requires
its text to travel with the fonts, which is why those four files are committed
rather than linked. And Saira carries "Saira" as a Reserved Font Name, so a
modified copy may not keep the name — which is the reason none of the files
here is subsetted, hinted or renamed beyond the weight-and-subset suffix.