Give every movement its own period interior.

Movement halls routed 24 of the 26 movements through 8 generic detail kinds,
four of which (modern, industrial, atelier, museum) rendered nothing at all,
and `salon` was a single ceiling ring shared by eight movements.

`details` is now a 26-value MovementDetailKind, one per movement, each built
from the architecture of the same period as the movement itself. Gothic and
Byzantine are unchanged and stay in MovementHallDetails.tsx as the reference
implementations; the rest live under components/hall-details/, split by era,
over shared wall-flush primitives.

hall-details/geometry.ts records the budget the Gothic and Byzantine
components established, since frames hang 0.23 m proud with a 0.7 m clear
margin at each wall end: relief limits above and below the frame line, corner
pockets for freestanding masses, doorway and title-band clearance, and a cap
of two added lights per hall. Halls now pass their computed windows down so
upper-wall panels, arches and roundels step around the openings.

Also holds the pale interiors back from blowing out: gallery wall tints are
authored around 0.50-0.56 luminance instead of near-white, and the 19 halls
that read too bright take lightScale 0.30, matching the basilica.

Verified by rendering all 26 interiors offline at two hall sizes and
measuring the scene graph: nothing through walls, floor or ceiling, maximum
0.17 m intrusion into the hang zone, at most two added lights per hall.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Documentation/basics.md

@@ -37,7 +37,8 @@ Gallery/
 │   │   ├── components/GalleryLoadingMarker.tsx  # Loading spinner overlay/banner (catalog, portraits, halls)
 │   │   ├── components/GalleryWindows.tsx  # Side-wall daylight windows (movement)
 │   │   ├── components/HallPassage.tsx     # Open archway between movement wings
-│   │   ├── components/MovementHallDetails.tsx  # Period architectural details
+│   │   ├── components/MovementHallDetails.tsx  # Period architecture dispatcher (Gothic + Byzantine reference)
+│   │   ├── components/hall-details/            # One period interior per movement + shared primitives
 │   │   ├── data/movement-interior-styles.ts    # Per-movement interior themes
 │   │   ├── utils/movementHallLayout.ts         # Wing split + window gap placement
 │   │   ├── utils/galleryProceduralTextures.ts  # Hi-res wall/floor textures
@@ -353,13 +354,14 @@ Enter from the home page by clicking a **movement name** on the movement flow. F
 | Wall order | Same U-shaped hang as artist halls (left → end → right) |
 | Frame captions | **Year · artist** label below each frame |
 | Period interior | Each of the 26 seeded movements maps to a unique style in `movement-interior-styles.ts` (Italian palazzo, Baroque palace, Byzantine basilica, NYC loft, white cube, etc.). Style keys use a legacy id map (`DB_ID_TO_STYLE_KEY`: gallery ids **1–26** → authored keys **27–52**, with Northern/High Renaissance swapped) so Byzantine gets the basilica, not Gothic stone |
+| Period architecture | Each style names a `details` kind (26 of them) that selects one component under `components/hall-details/` — the hall is built from the architecture of the **same period as the movement** (Roman entablature, Brunelleschi arcade, Flemish beam ceiling, Horta whiplash brackets, Rodchenko lattice, 1960s troffer grid). Gothic and Byzantine remain the reference implementations in `MovementHallDetails.tsx`; the geometry budget every module works to is documented in `hall-details/geometry.ts` |
 | Wall materials | Hi-res **procedural textures** with normal maps (`galleryProceduralTextures.ts`): real-world stone, marble, wood panelling, brick, velvet, stucco, **marble revetment** (framed book-matched panels), **Cosmatesque paving** (`marble-opus-sectile`), **coffered timber** ceilings, **blind-arcaded ashlar** (`gothic-ashlar`) and **ribbed vaulting** (`gothic-vault`) — plus **single-colour painted walls** (`painted-lime`, `painted-oil-matte`, `painted-oil-satin`, `painted-emulsion`, `painted-flat`) tinted per movement for Renaissance salons through modern white cubes |
 | Architecture in texture | Period halls that need arcades, vaults, or panelling draw that **relief into the texture** rather than adding geometry: `gothic-ashlar` paints a full storey (plinth → blind arcade → string course → triforium → cornice) into one tile whose `metersPerRepeat` equals `WALL_HEIGHT`, so it maps **once vertically** onto the wall; `gothic-vault` paints a quadripartite bay with tiercerons and a boss. Light/dark banding plus a high `normalStrengthFor()` makes it read as carved stone, keeping the mesh and light budget flat |
 | Door-flanking panels | Wall segments beside exit doors and passages take the hall's own wall texture (`GalleryWall` accepts `kind`/`tint`) instead of rendering as flat single-colour blocks next to textured walls |
 | Textures | Wall/floor/ceiling maps applied via `useTexturedMaterial`; movement **tints** drive painted-wall hue |
 | Windows | **Side walls only** — placed in gaps between frames when possible; if a wall is packed, high **clerestory** windows are still added so the hall keeps daylight (`computeSideWallWindows`). Styles are drawn in `GalleryWindows.tsx`; `gothic-lancet` builds a two-centred arch head from chords with a glazed spandrel, mullions, and transoms |
 | Lighting | Shared hall lights only (ambient / hemisphere / directional + capped ceiling track spots + one fill per window). See **light budget** below |
-| Period details | `MovementHallDetails.tsx` — classical / neoclassical use **shallow engaged corner pilasters** (never freestanding mid-hall or proud corner shafts that cover frames); `byzantine` adds engaged porphyry colonnettes with basket capitals, a marble revetment dado, and hanging brass polycandela; `gothic` adds bay-spaced compound piers with vault springers, transverse ribs arching across the nave, and a moulded string course — all flush to the side walls |
+| Period details | `MovementHallDetails.tsx` dispatches to one module per movement. `byzantine` adds engaged porphyry colonnettes with basket capitals, a marble revetment dado, and hanging brass polycandela; `gothic` adds bay-spaced compound piers with vault springers, transverse ribs arching across the nave, and a moulded string course. Every other movement follows the same rules in `components/hall-details/`: orders and piers stay **flush to the side walls** (≤ 0.17 m proud), freestanding masses only in the corner pockets, and no more than two added lights per hall — see `hall-details/geometry.ts` |
 | Back wall | Single wing: solid display wall. Multi-wing: **Exit double doors** → **Wing navigator** or **Exit to Timeline** |
 | Front / entrance wall | Single wing: **Exit double doors** (leave the way you entered). Multi-wing: **“Next wing →”** archway when a later wing exists |
 | Influence lamps | Same golden upside-down emissive fixtures as artist halls when `has_influence_links` is true (shared rail: 40 cm above the tallest frame in the wing) |
@@ -395,7 +397,11 @@ Full guide: [tours.md](tours.md).
 
 **Light budget (critical):** Three.js forward shading cannot compile `MeshStandardMaterial` with dozens of dynamic lights. Large wings used to add **one `spotLight` per painting** (plus influence lamps), which pushed the scene to ~100–200 lights — walls, floor, and ceiling then rendered as a black void while painting canvases (`MeshBasicMaterial`) still showed. Halls therefore use **shared lighting only**: ambient / hemisphere / directional fill, a small set of ceiling track spots (`GalleryTrackLights`, capped), and **one** window spot each. Painting canvases stay unlit (`MeshBasicMaterial`); frames and influence fixtures use **emissive** accents instead of per-frame lights. Intensities are scaled for three.js physical lights (post-r155).
 
-Shared lights carry a **brightness floor** so dark period styles never render as a black void. A style that is *meant* to be dim (a basilica lit by window shafts, not flooded) sets **`lightScale`** in `movement-interior-styles.ts` — it multiplies the scene ambient/hemisphere/directional/fill lights, the hall point lights, the ceiling track spots, and the HDR `environmentIntensity`. It defaults to **1**, so only styles that opt in are affected. Window fill lights are deliberately **not** scaled, so the daylight shafts still read against the darker room.
+Shared lights carry a **brightness floor** so dark period styles never render as a black void. That floor is high enough to blow out a pale wall, so **`lightScale`** in `movement-interior-styles.ts` is the knob that holds a hall back — it multiplies the scene ambient/hemisphere/directional/fill lights, the hall point lights, the ceiling track spots, and the HDR `environmentIntensity`. Window fill lights are deliberately **not** scaled, so daylight shafts still read against the darker room.
+
+It defaults to **1**, but most halls now set it: Gothic uses **0.26**, Byzantine **0.30**, and the 19 formerly pale interiors (Roman through Pop Art) also use **0.30**. Only the five halls that are already dark by albedo — Symbolist, Expressionist, Surrealist, Baroque, Romantic — stay at 1, since scaling their lights would crush walls that already sit at 0.15–0.27 luminance.
+
+**Wall brightness is albedo × `lightScale`.** Gallery walls are authored well below white for that reason: the reworked interiors sit around **0.50–0.56** wall luminance (0.66 for the two white-cube halls), landing at an effective 0.14–0.20 — the range Gothic and Byzantine established. Reach for `lightScale` before darkening a tint further; the two multiply, and dimming the hall dims the paintings with it.
 
 **Period architecture:** Freestanding columns must not sit in the walkway or in the corner pocket in front of frames (hang margin is only ~0.7 m from each wall end). Classical / neoclassical details use **engaged corner pilasters** flush to the walls (`MovementHallDetails.tsx`).