# Edge-lit active row — dark rail, magenta terminal, clipped bloom

Learned 2026-08-13 replicating reference R#4 (node 150:4341 → replica
`R#4-replica` 152:9, page Glass Morphism, Quorra v.0). A product
screenshot of a dark SaaS sidebar, one saturated colour in the whole
frame.

- **The lit edge is the fill, not an object.** The active row's own
  linear gradient runs flat graphite across four fifths of its width,
  then climbs in the last tenth: measured 66 at 88.5%, 100 at 95.5%,
  191 at 98.9%, 221 at the edge. The corner radius clips it, which is
  what produces the tapered ends. Building it as a separate rod on top
  reads as a different design at a glance and was the blind pass's
  first finding.
- **The bloom is a blurred sibling behind the row**, not a drop shadow
  on it: a 20px rect with LAYER_BLUR 16 plus a fainter 26px one at
  blur 34 and 34% opacity. A shadow spreads on every side; only the
  right side should glow. Measured decay: +24 levels at 11px past the
  edge, +12 at 21px, gone by 45px.
- **A top rim, no border.** The row carries a diffuse white highlight
  along its top edge only (85 → 71 → 50 across 3px), and no stroke on
  the other three sides. A 1px stroke all round is the tell of a
  rebuilt component.
- **The field is radial from the top-left corner**: 43 at (20,60)
  falling to 21 at (620,60) on the same row, flat by y=700. The base
  ramp must describe the far side and a large soft white ellipse (9%
  → 0 over ~620px) supplies the near corner. A vertical gradient alone
  over-lights the whole right half.
- **Nested panels are separated by hairlines, not by fill.** Three
  rounded rects at x=713, 799, 843 share the same 22-level interior;
  only the innermost lifts to 34. The rims (36-39) do the dividing.
- **Connotes**: one saturated colour in a monochrome frame is a
  spotlight — selection as electricity rather than as paint, the same
  discipline the house system applies to gold. Outline icons and
  sentence-case labels withhold weight, which reads as instrument
  rather than shopfront; the nested dark panels say depth without
  drawing a single divider line across the content.