The dorveille is a room you read in: its words are the fringe, the only lit thing in the dark. This is the room you work in. The void is a place you write in, and the words you write are the light. The page is dark until you write — the register below is empty, and the empty register is the void. The moment you write, the room lights itself at the work's own level: the hand's lamp, the fourth lamp.
Write. The work is the light: each line you write is lit at the penumbra's own level — the boundary's light, relocated — and the lines you have written keep the light they were written in. The next line waits at e−1; the void resumes 0.916 line-heights below the last. The ember — the band between the last line's level and the void — has a surface now: the strip below the register is the work's own tail, its height the ember's own depth (ln(0.30/0.12) × the room's line-height), gold at the last line's level and void at its bottom, where the void resumes. What you write here stays in this browser: the work done in the thirty-first hour is real, and it remains.
The map of the light names three lamps and the inverse: the reader's (gaze-anchored, unit the viewport), the place's (page-anchored, unit the page's own height), the clock's (time-anchored, unit the 31-minute beat), and the inverse — the dark's own, no time term, no scroll term, lit only at its fringe. This page is lit by a fourth kind, the one the map's drawing cannot show: the hand's lamp, work-anchored, unit the line. It does not breathe with the beat and it does not follow the gaze — it appears where the work appears, and it is gone where the work is not. A lamp that only exists while someone works cannot be drawn in a static register; it must be used to be seen. The dial below is the lamp's instrument, not its portrait: beside the law's own curve it draws the hand's cursor — the line the next keystroke writes, measured from the register's real geometry and placed on the law's own axis, line-heights from the last line, never page-pixels. The law has no scroll term; the marker has none either — only the work's own coordinate. Type, and the caret rides the rule; edit an earlier line, and it climbs into the work's light; overflow the box, and the register's scroll is named as a room fact, never as a position. And the light below the work uses the same measurement as the instrument: it falls from the work's own last line — the text's true edge, in the work's own coordinate — never from the box's edge. The box is a window onto the work, not the work's boundary: when the work overflows the fixed box, the ember begins where the work actually ends, and a long work lights a long room. And the ember is no longer only a reading: the strip below the register is the ember's own surface — its height the ember's own depth, its paint the law's own gradient, its bottom edge the void line. The lamp lights, the dial reads, the strip shows: three surfaces, one measurement. And the strip's record is static now: the twin below is the same gradient, stopped and parsed by the wall — the first gradient the checks prove by construction; the live strip stays the use, the twin is the record.
The law: workAt(depth, workTop, workBottom, lineHeight) — above the work, the void stays void (the work does not light the room above it); within the work, the light is the penumbra's own level, so the written words keep the light they were written in; below the work, the light falls one e-fold per line-height, the next line waiting at e−1. No time term, no scroll term — a hand term. The work is the only motion the dark permits, and the work is the light.
The same argument the dorveille made, one step further. A black box with a gold stripe is a stage prop, because its dark is a costume — painted on, indifferent to the hand. This page's dark is structural: the light is generated by the work itself. An empty register is void — not decorated void, actual void, the same ink and the same discipline with the lamps turned off. Write, and the light appears at the work's own position, gold at the edges of your words, zero beyond them. The strip below the register is not the prop's stripe: its paint is the law's own gradient — goldMix sampled down the ember band, the same function that lights the page — and its height is the ember's own depth in the room's real line-heights, so the stripe is the light, not a costume of it. The workbench is never a lit room — only a lit page, and only while the work is on it.