# Principles

Lamplight is seven principles and a shared core, adapted across modes and surfaces. Night and Day
are modes: what the light is doing. Study, Ledger and Folio are surfaces: what the thing is and
how it's used. Each one names a real situation and answers the same five questions about depth,
emphasis, state, motion and density.

## Principles

**1. Honest materials.** Protects: honesty.
- Night: Light glows.
- Day: Ink doesn't, so depth comes from paper tone and rules.
- Ledger: Alignment, columns and rules do the work.
- Folio: Ink on plain paper, with nothing that moves.

**2. One thing at a time.** Protects: focus.
- Night: One lit thing per view.
- Day: One dark block or one heavy mark.
- Ledger: One lead per region.
- Folio: One lead per page.

**3. Keep it calm.** Protects: calm.
- Night: Plenty of space and few items.
- Day: The same, with wide margins.
- Ledger: Long lists are fine if they're grouped and aligned.
- Folio: A clear grid, and ideas don't split across pages.

**4. Tell the truth about state.** Protects: trust.
- Night: The colour of the light changes.
- Day: The ink colour changes, with a word beside it.
- Ledger: State gets its own column so rows can be compared.
- Folio: It's dated, for example "as at 30 October".

**5. Movement needs a reason.** Protects: stillness.
- Night: Light responds to the hand.
- Day: The same, but much fainter.
- Ledger: Fast responses and no ambient movement.
- Folio: None.

**6. Everyone can read it.** Protects: access.
- Night: AA contrast, a clear focus ring and full keyboard use.
- Day: The same, with colours darkened for paper.
- Ledger: Real tables, full keyboard use and a layout that works on a phone.
- Folio: It still makes sense in black and white, PDFs are tagged, and link addresses are printed.

**7. Talk like a person.** Protects: dignity.
- Night: "One answer is waiting", not "1 pending item".
- Day: The same voice.
- Ledger: Shorter labels in plain language.
- Folio: It makes sense without you there to explain it.

## Marks inside panels

Coloured top or left border bars on rounded panels are not Lamplight. Use an
internal straight Lead line to mark a region, or a Thread to connect a sequence.
This guidance does not prohibit functional one-pixel boundaries that separate
or identify controls and content.

## Fixed and flexible

Three things are fixed everywhere, and only these are enforced by build checks:

- Principle 6.
- State is never carried by colour or motion alone.
- Red is for genuine errors.

Everything else is a default that a mode or surface can answer in its own way. Taste stays as
guidance. Token and class drift checks stay, because they protect the build rather than steer
behaviour.

## Modes and surfaces

Night is the default mode; Day is ink on parchment. Study is the default surface. Mode and surface
are separate choices, so Ledger can be used in Night or Day. Folio is always ink and is also applied
automatically when printing.

### Ledger

The working desk with papers spread out. It serves material people scan, compare and return to.

| Question | Answer |
|---|---|
| Depth | Alignment, columns and rules; fewer panels |
| Emphasis | One lead per region |
| State | Its own column, as a word or glyph |
| Motion | Fast responses; no sheen or wire gleam across rows |
| Density | Tighter tables and tabular numbers; long lists allowed when grouped |

Ledger leads are lighter than Focal Catch and separate from it. Focal Catch stays at one per view.

### Folio

The sheet that leaves the room. It serves print and PDF, and is always ink.

| Question | Answer |
|---|---|
| Depth | Rule weight and type size; no printed ground |
| Emphasis | One lead per page, carried by the heaviest rule or largest type |
| State | Dated, with no live claims |
| Motion | None |
| Density | Set by page size, with a clear grid and running heads |

The paper's own colour is the ground. Use shape or line cues alongside colour, replace interactive
controls with what they currently show, and adapt wide content to the page so it is not clipped.