# IZ4 brand guidelines

## The idea
IZ4 ("is for") preserves the purpose and human-first invariants beneath changing software. An `iz4`
file sits beside a project's README and records what the software is for, who it is for, and the
invariants that must stay true. Every file carries the foundation.

**The mark.** Four people holding hands, seen from above. Four small hollow diamonds - the people,
the foundation invariants - stand at the corners. A closed inner band binds them; along each side an
outer band runs from one figure toward the next and meets its neighbour's at the middle: the hands.
The diamond space they hold between them is what the software is for. It is empty in the trademark
drawing, green when a project has declared, and carries a QR code in the live badge.

Never draw the people. The reading is the viewer's discovery; the geometry stays pure.

**Words.** "The diamond holds what the software is for. The people around it keep it true."
Supporting line: *Intent, held in alignment.* Product name in prose: **IZ4**. Wordmark, domain
and CLI: lowercase **iz4**. The badge shows that a public declaration exists; it is never proof,
certification or assurance.

## Geometry - one rule
Every dimension is a golden-ratio step from the stroke:

| element | value | rule |
|---|---|---|
| stroke | 11 | the unit |
| corner loop (half-diagonal) | 28.8 | stroke × φ² |
| diamond (half-diagonal) | 122 | loop × φ³ |
| band gap and hands gap | 4.2 | stroke ÷ φ² |
| loops stand proud of the corner | 11 | one stroke |
| green diamond (half-diagonal) | 46.6 | diamond ÷ φ² |
| lockup: wordmark height, gap to mark | mark ÷ φ, mark ÷ φ² | |

All edges are at 45°. Master viewBox 0 0 400 400; the device spans 324 units. Fills only: no
strokes, gradients, shadows, bevels, 3D, text or pictograms in the device.

## Colour
- Ink `#1c1a17` · Paper `#f5f1e8` · Green `#1f9156`
- Green is used only for the centre diamond (the declaration) and the i's dot in the wordmark.
  Never on the bands, loops, or anywhere decorative. No tints, no gradients, no second accent.
- Reversed: paper on ink, green unchanged. SVG masters are transparent and use `currentColor`.

## Sizes
| context | asset | minimum |
|---|---|---|
| hero, seal, print, social image | `iz4-mark-declared.svg` | 48 px |
| header | `iz4-lockup.svg` (or the wordmark alone) | 96 px wide |
| live QR badge | generated per project | 280 px wide (OpenCV floor; phones do better) |
| README pills | `iz4-badge-20/32*.svg` | as built (20 / 32 px) |
| favicon and app icons | `iz4-favicon.svg`, `icons/` | 16 px |

Clear space around the master: at least one corner loop (29 units, ≈ 9 % of the device) on all
sides. Never stretch; never rotate; never recolour the bands.

## The badge
- Each project's live badge encodes that project's canonical card URL and links the whole badge
  to it. Keep card URLs short (`iz4.you/c/<id>`) - every extra QR version raises the size floor.
- Label: "View this project's IZ4 declaration".
- README pills carry the green diamond as the token - not a miniature of the device.

## Do not
Add a person, heart, lock, shield, hand, tick or arrow · put letters inside the device · colour the
bands or loops · thicken or thin one element without the others · round the corners · add a twist
or over-under to the bands (the resolved mark has none) · reintroduce pillars, plinths, tiled
borders or the earlier knot · use the QR at favicon sizes · describe the badge as certification.

## Trade mark
File separately: the word **IZ4** (standard characters); the device (`trademark/IZ4-device-mark-mono`)
in black and white, no colour claim, with the green and reversed versions as a series; and the
composite device + wordmark. Classes 9 and 42 (consider 41, 35). UK IPO first, then Madrid for the
EU and others. The registered drawing must match the drawing in use: this one.

Description for the application: "A diamond-shaped device formed of two concentric bands, the inner
band continuous and the outer band interrupted at the middle of each side, with a small hollow
diamond at each of the four corners, enclosing an open central diamond space."

## On the register (rulings since the handoff)
- README pills are always a project's own, at `/p/<id>/badge.svg`, drawn by `lib/IZ4/Badge.pm`. A pill
  states what that project's card states, from the same calculation, and carries the green token and
  "we use iz4" only while the project's badge is issued and its evidence shows the declaration present
  with a passing syntax check (IZ4 Invariants 5 and 28). Otherwise it carries an empty diamond and the
  card's words. There is no pill that says "we use iz4" on its own, so none is served.
  Markdown: `[![IZ4](https://iz4.you/p/<id>/badge.svg)](https://iz4.you/p/<id>)`
- The register mints each live badge itself (`lib/IZ4/Device.pm`), with the same numbers as
  `build_assets.py`.
- The i's dot sits 8 units higher in the light wordmark and 12 in the bold, in the wordmarks and the
  lockup, so it stands clear of the stem's notch and never reads as an l.
- The site's footer is reversed (paper on ink) and carries the declared mark, green centre and all, to say
  this is the IZ4 site; the handoff's mono footer mark is not used on the site.
- Hyphens, never em dashes; the site title stays "IZ4 - Intention Protection for Humans".
- On the site the four figures and their bands are read as the foundation, as one
  piece; the green diamond at the centre is the project's own, by name.