The colour system
It is a field, not a gradient.
A gradient is a ramp between stops. This is four sin and cos iterations displacing the UV coordinates, then two time-driven waves mixing four hues. No start, no end, never repeats. These four are the entire accent system. There is no fifth brand colour.
The shader in LivingBackground.tsx is the source of truth. If these hexes ever disagree with it, the shader is right. This page previously documented four different values and every one of them was wrong.
The realism bar
Real engineers built this.
Cartoon is the failure mode. The widget below runs on requestAnimationFrame and reveals a real before and after through a clip-path wipe, with a beam that has mass. 203 lines. Realism is precision, not volume.
- It runs. Not a static picture of a thing that could run.
- It reveals through geometry, not an opacity fade.
- It shows the actual product at real fidelity, with real findings.
- No fake browser chrome, no traffic lights, no drawn screenshots.
- Existing widgets are the vocabulary. They get upgraded, never replaced.
Type
Three faces, each with one job.
Poppins carries headlines. General Sans carries everything readable. Geist Mono lives only inside product artifacts, never in marketing copy.
Sentence case everywhere in marketing copy. Mono-uppercase eyebrows and proof lines are banned. Marketing labels are sentence case, semibold, and hue-coloured.
Severity
Colour carries meaning, never decoration.
Numerals and borders carry severity. Never fill a whole box with it. These are separate from the field and are not accents.
Geometry
Rectangular and architectural.
Controls 6 to 8px. Frames 6px. Tags 3px or notched. Pills are banned: no rounded-full on anything that is not a dot.
Open decision: the primary button above is #2b5cff, the flat accent the homepage ships today. The field's blue is #2966FF. They are near duplicates, which is drift. Unifying them means touching the homepage, so it is a decision to make out loud rather than a silent change.
Authority
One truth. There is no second opinion.
DESIGN.md wins every contradiction. design-tokens.json is generated output. BRAND_GUIDE.md is an implementation appendix for logo files, PDF sizes and shadows. BRAND_VOICE.md owns copy only.
Three of those files each used to claim to be the single source of truth. That is how an agent talked itself into deleting the how it works page on 30 July 2026. If you are reading brand rules from anywhere but DESIGN.md, stop.