How this site is made

Parts

What it is built from

These are the direct dependencies, with the versions that the lockfile installs. A browser receives Preact and our own code and nothing else. The calculation kernel has no dependencies at all.

In the browser

Package	Version	Licence	What it does here
@astrojs/preact	6.1.1	MIT	Connects Preact to the pages.
preact	11.1.0	MIT	Draws the plates that you can change, and the receipt check.

In the Worker

Package	Version	Licence	What it does here
@astrojs/cloudflare	14.4.3	MIT	Runs the site on Cloudflare Workers, with D1 and R2.
valibot	1.5.0	MIT	Checks what the contact form and the receipt check receive.

At build and in tests

Package	Version	Licence	What it does here
@astrojs/check	0.9.12	MIT	Type checks the pages.
@astrojs/markdown-remark	7.3.5	MIT	Reads the front matter of essays and pages.
@astrojs/markdown-satteri	0.4.6	MIT	Turns Markdown into pages.
@axe-core/playwright	4.14.0	MPL-2.0	Scans every page for accessibility faults.
@fontsource-variable/archivo	5.3.0	OFL-1.1	The source of the face that the name of the site is traced from. It is not served.
@fontsource-variable/inter	5.3.0	OFL-1.1	The source of the Inter files, upright and italic.
@fontsource-variable/jetbrains-mono	5.3.0	OFL-1.1	The source of the JetBrains Mono file.
@fontsource/stix-two-math	5.3.0	OFL-1.1	The source of the STIX Two Math file.
@types/node	22.20.5	MIT	Types for the scripts that build and check.
astro	7.4.4	MIT	Builds the pages.
fast-check	4.10.2	MIT	Makes the inputs for the property tests.
github-slugger	2.0.0	ISC	Makes the same heading anchors in the pages and in the tests.
playwright	1.64.1	Apache-2.0	Drives Chromium, Firefox and WebKit for the parity check and the screenshots.
satteri	0.10.5	MIT	The Markdown processor under it.
sharp	0.35.5	Apache-2.0	Draws the icons, and reduces the pictures that links show to a small palette.
shiki	4.5.0	MIT	Colours code blocks while the site is built.
temml	0.14.0	MIT	Draws mathematics as MathML while the site is built.
typescript	6.0.3	Apache-2.0	Type checks every file.
vitest	5.0.5	MIT	Runs the tests.
wrangler	4.156.0	MIT OR Apache-2.0	Runs the Worker on this machine, with D1 and R2.
z3-solver	5.3.3	MIT	Checks the proofs. A second solver checks them again.

Colour

One blue and one orange

The page is a white leaf on a field of one saturated blue. A block that has to stand out is a flat panel of the blue, of the pale wash of it or of the orange, and everything else is drawn in the blue and in the night. The orange is for what is small and has to be found, a full stop, a crosshair or a tag, and is never the colour of words on white. No colour stands for a kind of page or a kind of product. Every pair of colours that the site sets against each other is held to a minimum contrast by a test that reads the style sheet.

Six grounds

• Leaf #FFFFFF The leaf that the page is on: white.
• Sheet #FFFFFF A sheet: anything that carries a figure, a table or a field, and the ink on the blue.
• Wash #ECF3FF The pale blue of a panel that is read, of the head of a table and of a band within a sheet.
• Blue #2455F6 The electric blue of the field, of the panels and of the button. White on it is 5.67 to 1.
• Night #121A30 The ink. Text and headings, the ground of a block of code, and the word on a button that sits on the orange. It is a blue-black.
• Orange #FF8F5A The orange as a ground, for a tag and for the panel that closes a page, with the night set on it.

The inks and the marks

• The link #1C40D6 The ink of a link and of the words that are the blue on a ground that is light, and the blue under the pointer on a button.
• The lesser ink #37425F Text of lesser weight on the leaf and on a sheet, such as a summary.
• The dot #E04F1A The dot of the mark: the one warm colour of the site, for what is small and has to be found, and never for words on white.
• The highlighter #FFE6D9 The orange as a pale ground: the highlighter, for the one thing on a page that is being pointed at.
• A check that passed #27603B A check that passed, on a ground that is light. Always beside a word.
• A limit #8A5200 A limit to read before relying on something. Always beside a word.
• An error #9A322A An error that the reader has to fix, on a ground that is light. The dark has its own, lifted. Always beside a word.

The grounds of a section are paper, white, wash, blue and signal. Each sets its own text, its lesser text and its marks, and a component reads them from the section that it stands in.