From fde030a699b3d6667d1fa21ae192b5011e3f373f Mon Sep 17 00:00:00 2001
From: Gabriel Schneider <gbrls@0x4200.cafe>
Date: Mon, 28 Sep 2026 23:50:56 -0300
Subject: Rules and chrome scale with the display's density; dark pages get
 visible separators and focus tints

Density: dp() in gui.zig draws every size given in pixels in logical
pixels (SDL's window display scale, rounded, at least one), as acme scales
Border, ButtonBorder and Scrollgap: the rules (rule_px), the tag rule, the
grip's ring, its dirty gap and mode bars, the rail's gap to the text and
its minimum, the thumb's inset, the rim, a bar cursor's minimum width,
underline and strikethrough thickness (the atlas is dropped on a scale
change), the rule-grab margin, and the Crt's scanline and mask periods
(pardesScale in the post prefix). Cell- and tagline-measured sizes stay:
the rail's width, Lift's blur and offsets, every motion; iResolution,
fragCoord and iMouse stay in the display's pixels, as ghostty's.
PARDES_TEST_SCALE forces a density in a harness (a test window is 1x
otherwise, whatever display it lands on) and sizes the test font with it.

Colours: a separator that stands off its page by less than 1.5:1 is lifted
toward the text to 1.6:1 (helix, atelier, paper; a theme with no page,
dark, is judged against #121212), and empty_col follows it. forge's own
rule already stands at 3.83:1; what hid it was density: 2 device pixels
on a 3x screen, now 6 (dp). A focused tag's tint closer than 1.5:1 to the
plain tag on a dark page (1.25:1 on a light one) is pushed further the way
it leans, as far as its text keeps its own contrast or 4.5: forge
1.23 -> 1.51 (#2d3440 -> #374253), and likewise dusk, orchard, ink,
lagoon, clay, harvest, spectrum, solarium, forge_soft; daybreak, atelier,
paper to 1.25. dark and helix gain a tint of their own (dark: #484566
under #c8c8c8, 1.54:1; helix: ramp 237 under 250, 1.65:1).

Tag caret: past a full row's end, the G3 glide box sits on the tag's right
edge, where the layer's caret and the pixel shell's are.

Tests: every native theme's separator >= 1.5 and every dark one has a
tint >= 1.25 with readable text; forge keeps its own border; the tag caret
glide box at a full row; at 2x the spine, tag rule, ring, rail start and
gap, and bar cursor double. Legacy-ThemeFile test strips helix's new pair.

Goldens: snapshot goldens change in colour rows only, the tints (orchard
#283a2f -> #314738 at boot, forge, helix and dark in theme/themesel).
GUI goldens: the harness's single Del of the renamed wide pane is refused
since ysqnkyoy (a rename counted as unsaved; fixed on the 9P line in
wkzlsqvy), so scenes 09-17 were recorded with that pane open and the file
was stale since the merge (08 and 18 also moved with ykvnltvs's full-row
tag wrap). The goldens here were recorded with that pane closed (as
wkzlsqvy will close it); against the parent's binary under the same
conditions they differ only in the tints: 01-13 forge's (#2d3440 ->
#374253, and the glyph edges on it), 14 ink's; 15-18 are byte-identical.
Until wkzlsqvy is merged, a run here fails 09-17. Each commit reproduces its own
recorded goldens on this machine (checked at kvtmqkyn). A test window is
1x unless PARDES_TEST_SCALE says otherwise, whatever display it opens on.
Prebuilt shaders refreshed from their sources.
Captures: .scratch/render/dark-borders/{before,after,compare,scale2,scale3}.
---
 shaders/prebuilt/ui.frag.spv | Bin 5700 -> 5700 bytes
 1 file changed, 0 insertions(+), 0 deletions(-)

(limited to 'shaders/prebuilt/ui.frag.spv')

diff --git a/shaders/prebuilt/ui.frag.spv b/shaders/prebuilt/ui.frag.spv
index 033c10ab..c8ee1604 100644
Binary files a/shaders/prebuilt/ui.frag.spv and b/shaders/prebuilt/ui.frag.spv differ
-- 
cgit v1.3


From 09ec515c5e94de741104038cd61f18b2b997e78c Mon Sep 17 00:00:00 2001
From: Gabriel Schneider <gbrls@0x4200.cafe>
Date: Tue, 29 Sep 2026 06:04:28 -0300
Subject: G5: lapis, 0x4200.cafe's manuscript, as a theme with its ornament

A native theme `lapis` (src/themes/lapis.zig) from web/theme/lapis.css:
a lapis-deep page, lapis tags with gold names, vellum text, vermilion
rubrics, gold rules and a vermilion tag rule, gold selection in lapis ink.
Its ornament is the theme's new `decor` (colors.Decor), drawn by a pixel
shell inside the chrome it already has (decision 1), all of it off every
focus indicator:

- page_dots: the site's gold dot grid (#e8c46a22, 22 px), drawn by the
  cell shader on page-coloured cells alone (flag 0x10000000), so it lies
  under the text and never under a selection, a tag or the cursor; fixed
  to the window, a page the panes lie on.
- rail_checker: the dither frame's gold and lapis checker in the scroll
  track (a decor kind, flag 0x08000000), anchored to its rail; the thumb
  stays solid gold.
- tag plaques (tag_border, tag_shadow, tag_stripe): every tag a raised
  plaque inside its own band, the site's trail: a 2px gold frame and a
  hard 5px vermilion shadow down and right, both within the band's rows
  and columns (down, what the slack under the text leaves), so no shadow
  reaches a body, a grip or the next pane. The focused pane's plaque is
  the code window's title bar, gold and lapis stripes of 2px, its words
  on plates of the focused ground; unfocused ones are plain; column and
  workspace tags take the object-label language (1px frame, 2px shadow
  toward the page). Drawn as decor under the cells (a group's under
  range), with blank tag cells see-through and the cells blended
  premultiplied (pipeline_over) on such frames; opaque windows only.
- title_shadow: the titles' vermilion offset shadow under a file name's
  letters, sampled in the cell shader inside the letters' own cells (flag
  0x08000000), none on a cursor.

Chrome carries the decor (decor_*, name_ink, active_name_ink); a theme
file folds a nested decor literal field by field. Left out, with why, in
docs/effects.md: the fonts, the ornaments, a decor crossfade, and in the
tty anything but the colours (a tag row has no spare cell for a shadow).
An empty column is the page. The effect id is masked to 27 bits (ui.vert/ui.frag) for the
fifth flag.

Tests: the cell flags land only on page ground and file-name cells, never
a cursor, nothing without decor; lapis's plaques stay inside their tag's
band, clear of every grip, only the focused one striped; its checker is in
the track; no other theme draws any; the separator and focus
tests cover lapis. Goldens: theme and themesel (the ring gains lapis after
acme). Gates as G4. Feel review: .scratch/render/lapis/ (lapis.png, lapis-2x.png,
tags-focused-vs-unfocused-2x.png, a PanelSlide at 60 fps and a quarter).
---
 docs/effects.md                  |  29 ++++
 docs/themes.md                   |   1 +
 shaders/decor.frag.glsl          |  13 ++
 shaders/prebuilt/decor.frag.glsl |  13 ++
 shaders/prebuilt/decor.frag.spv  | Bin 6560 -> 7852 bytes
 shaders/prebuilt/ui.frag.glsl    |  32 +++-
 shaders/prebuilt/ui.frag.spv     | Bin 5700 -> 8448 bytes
 shaders/prebuilt/ui.vert.glsl    |  10 +-
 shaders/prebuilt/ui.vert.spv     | Bin 5612 -> 5612 bytes
 shaders/ui.frag.glsl             |  32 +++-
 shaders/ui.vert.glsl             |  10 +-
 src/colors.zig                   |  49 +++++-
 src/detached/wire.zig            |   2 +-
 src/draw.zig                     |  17 ++
 src/gui/gui.zig                  | 335 ++++++++++++++++++++++++++++++++++++++-
 src/surface.zig                  |  20 +++
 src/themes/lapis.zig             |  92 +++++++++++
 test/snapshots/theme.golden      |  62 ++++----
 test/snapshots/themesel.golden   | 126 +++++++--------
 19 files changed, 729 insertions(+), 114 deletions(-)
 create mode 100644 src/themes/lapis.zig

(limited to 'shaders/prebuilt/ui.frag.spv')

diff --git a/docs/effects.md b/docs/effects.md
index 8073c50a..8a60d116 100644
--- a/docs/effects.md
+++ b/docs/effects.md
@@ -38,6 +38,7 @@ why. The verdict is the user's.
 | G1 lift | `Lift shadow\|rim\|auto` (off), `InactiveDim <percent>` | opt-in until the focus-lift default is decided | lift-shots-2 (off, shadow, rim, auto on acme, dusk, forge); frame series + mp4 per Motion flavour | shadow on acme: keep as is. Round 1 dropped glow and surface (surface lowered the focused text's contrast) and made rim a hairline just above the focused tag (light on a dark page, shade on a light one). auto on a dark page recedes the others (InactiveDim 30) |
 | G3 cursor | follows `Motion`; `CursorBlink on\|off` (on) | glide on by default through the default flavour (smooth); blink on (decision 6) | .scratch/render/cursor/cursor-flavours-grid.mp4 (and quarter speed), raw/<flavour>/<motion>/ | pending |
 | G4 bloom, vignette, grain | `Bloom`, `Vignette`, `Grain` `0..3` (off) | bundled post passes; none touches a tag, grip, notice or the cursor (pardesSpare); each capped per theme (pardesCap) | .scratch/render/{bloom,vignette,grain}/ (levels 0-3 on forge, dusk, acme; crops; mp4 stepping through the levels) | pending |
+| G5 lapis | `Theme lapis` (its `decor`) | a native theme with ornament: tag plaques with hard shadows inside their bands (the focused one striped), dots, rail checker, title shadow | .scratch/render/lapis/ (whole window at 1x and 2x, crops, a slide mp4) | pending |
 
 ## Motion flavours
 
@@ -114,3 +115,31 @@ is round, starts halfway to a corner and reaches 10, 18 and 28%. Grain is
 Found on the way: SDL GPU binds at most 4 KiB of a uniform block, so every
 Shadertoy colour after the palette (iBackgroundColor and on) read zero; the
 block is now cut in three with ghostty's names and order kept.
+
+Notes on G5: lapis (src/themes/lapis.zig) is 0x4200.cafe's lapis.css in
+pardes's chrome, drawn inside it (decision 1). The tags are the site's
+trail and title bars: every tag a plaque in its own band, framed in gold
+(2 px, the trail's border) with the trail's hard vermilion shadow (5 px)
+down and right, the frame and the shadow both inside the band's rows and
+columns, so no shadow reaches a body, a grip or the next pane; down, the
+shadow gets what the band's slack under the text leaves (a pixel or three
+at a tagline under the body's size, more at a larger one), to the right
+its full offset. The focused pane's plaque is the code window's title bar,
+gold and lapis stripes of 2 px, its words on plates of the focused ground
+(the words' cells stay opaque, the blanks between let the stripes show),
+so the focus indicator is plainer to see than any theme's tint, never
+less; the unfocused ones are plain. Column and workspace tags take the
+quieter object-label language: a 1 px frame and a 2 px shadow of vermilion
+toward the page. The plaques are decor drawn under their cells (a group's
+under range) with the cells blended premultiplied over them; blank tag
+cells on the tag's ground are see-through there. They need an opaque
+window: under WindowOpacity 100 the tags are plain. Also from the site:
+the colours (lapis-deep page, vellum text, gold names and rules,
+vermilion rubrics and tag rule, gold selection in lapis ink), the page's
+gold dot grid (22 px, #e8c46a22) on page-coloured cells only, fixed to the
+window; the dither frame's checker in the scroll track, anchored to its
+rail (the thumb solid gold); the titles' vermilion offset shadow under a
+file name's letters. Left out: Crimson Pro and Departure Mono, the
+ornaments, a decor crossfade (it snaps while the colours fade). The tty
+shows the colours alone: a tag row abuts its body and its neighbour, so
+there is no cell for a shadow row or column.
diff --git a/docs/themes.md b/docs/themes.md
index 2b15051e..38596819 100644
--- a/docs/themes.md
+++ b/docs/themes.md
@@ -121,6 +121,7 @@ so existing exported themes remain valid.
 | `rule_px` | Pixel shells: the width of the rules between columns, between panes stacked in a column, and under the workspace and column tags, in `border` (the rule between a tag and its body is always one pixel), in logical pixels: doubled on a 2x display, as acme scales its Border | 2 |
 | `box_border`, `box_dirty` | The grip is acme's button: `box` filled when focused, else a two-pixel ring of `box_border` round the tag's ground; `box_dirty` fills it inside either ring while its file is unsaved (a grid, which has no ring, shows a bold `*` on `box_dirty` in the grip's second cell) | `box_dim`; `diagnostic_warning`, then `num` |
 | `rail_px` | Pixel shells: the scroll column's width, the grip's button over the scrollbar (thumb a pixel narrower), in pixels at a 17px tagline, scaled with it | 12, acme's Scrollwid |
+| `decor` | Pixel shells: a theme's ornament, drawn inside the chrome it has (lapis's): `page_dots` (a dot grid on the page's own ground, `page_dot_alpha` strong every `page_dot_px`), `rail_checker` (a checker in the scroll track, squares of `rail_checker_px`), `tag_border`, `tag_shadow`, `tag_stripe` (every tag a raised plaque inside its own band: a `tag_border_px` frame round its text and a hard `tag_shadow_px` shadow down and right, both inside the band's rows and columns; the focused pane's plaque striped `tag_stripe_px` with its words on plates of the tag's ground; column and workspace tags a quieter one; opaque windows only) and `title_shadow` (the file name's offset shadow, `title_shadow_px`), sizes in logical pixels. None of it touches a focus indicator | none |
 
 Native palettes give filenames a distinct hue at approximately the same
 brightness as the surrounding tag text. This also applies to output names
diff --git a/shaders/decor.frag.glsl b/shaders/decor.frag.glsl
index 3e2c286f..bb1ef0d6 100644
--- a/shaders/decor.frag.glsl
+++ b/shaders/decor.frag.glsl
@@ -8,6 +8,8 @@
 // colour rides in the cell's ground (a_bg), its coverage in a_fg.r, so the
 // result is the overlay pipeline's exactly.
 //
+// Checker (flag 0x08000000): two colours in squares, or in stripes, see main.
+//
 // Soft (flag 0x10000000): a rectangle's shadow, rim or glow blurred by a Gaussian,
 // in closed form (the product of two erf edges), on one quad grown by 3
 // sigma: no blur pass. Everything is in the quad's own 0..1 space, so a
@@ -51,6 +53,17 @@ void main() {
     if (v_clip.z >= v_clip.x && (gl_FragCoord.x < v_clip.x || gl_FragCoord.x >= v_clip.z ||
         gl_FragCoord.y < v_clip.y || gl_FragCoord.y >= v_clip.w)) discard;
     float opacity = clamp(u_ui.background_opacity, 0.0, 1.0);
+    // Checker (flag 0x08000000): squares of v_uv.x pixels from the quad's
+    // own corner, so it moves with its rail, in the ground's colour and the
+    // ink's (lapis's scroll track).
+    vec2 in_quad = v_cell_uv / max(vec2(dFdx(v_cell_uv.x), dFdy(v_cell_uv.y)), vec2(1e-6));
+    if ((v_effect.x & 0x08000000u) != 0u) {
+        ivec2 q = ivec2(floor(in_quad / max(v_uv.x, 1.0)));
+        // v_uv.y set: stripes across the quad (lapis's title bar), not squares.
+        int k = v_uv.y > 0.5 ? q.y : q.x + q.y;
+        o_col = vec4(((k & 1) == 0 ? v_bg : v_fg) * opacity, 1.0);
+        return;
+    }
     if ((v_effect.x & 0x10000000u) == 0u) {
         o_col = vec4(v_bg * opacity, v_fg.r);
         return;
diff --git a/shaders/prebuilt/decor.frag.glsl b/shaders/prebuilt/decor.frag.glsl
index 3e2c286f..bb1ef0d6 100644
--- a/shaders/prebuilt/decor.frag.glsl
+++ b/shaders/prebuilt/decor.frag.glsl
@@ -8,6 +8,8 @@
 // colour rides in the cell's ground (a_bg), its coverage in a_fg.r, so the
 // result is the overlay pipeline's exactly.
 //
+// Checker (flag 0x08000000): two colours in squares, or in stripes, see main.
+//
 // Soft (flag 0x10000000): a rectangle's shadow, rim or glow blurred by a Gaussian,
 // in closed form (the product of two erf edges), on one quad grown by 3
 // sigma: no blur pass. Everything is in the quad's own 0..1 space, so a
@@ -51,6 +53,17 @@ void main() {
     if (v_clip.z >= v_clip.x && (gl_FragCoord.x < v_clip.x || gl_FragCoord.x >= v_clip.z ||
         gl_FragCoord.y < v_clip.y || gl_FragCoord.y >= v_clip.w)) discard;
     float opacity = clamp(u_ui.background_opacity, 0.0, 1.0);
+    // Checker (flag 0x08000000): squares of v_uv.x pixels from the quad's
+    // own corner, so it moves with its rail, in the ground's colour and the
+    // ink's (lapis's scroll track).
+    vec2 in_quad = v_cell_uv / max(vec2(dFdx(v_cell_uv.x), dFdy(v_cell_uv.y)), vec2(1e-6));
+    if ((v_effect.x & 0x08000000u) != 0u) {
+        ivec2 q = ivec2(floor(in_quad / max(v_uv.x, 1.0)));
+        // v_uv.y set: stripes across the quad (lapis's title bar), not squares.
+        int k = v_uv.y > 0.5 ? q.y : q.x + q.y;
+        o_col = vec4(((k & 1) == 0 ? v_bg : v_fg) * opacity, 1.0);
+        return;
+    }
     if ((v_effect.x & 0x10000000u) == 0u) {
         o_col = vec4(v_bg * opacity, v_fg.r);
         return;
diff --git a/shaders/prebuilt/decor.frag.spv b/shaders/prebuilt/decor.frag.spv
index 3256f2b1..bd565d03 100644
Binary files a/shaders/prebuilt/decor.frag.spv and b/shaders/prebuilt/decor.frag.spv differ
diff --git a/shaders/prebuilt/ui.frag.glsl b/shaders/prebuilt/ui.frag.glsl
index dca224ba..62dbbfa2 100644
--- a/shaders/prebuilt/ui.frag.glsl
+++ b/shaders/prebuilt/ui.frag.glsl
@@ -10,6 +10,12 @@
 layout(set = 2, binding = 0) uniform sampler2D u_atlas;
 layout(std140, set = 3, binding = 0) uniform UiUniforms {
     float background_opacity;
+    // A theme's ornament (colors.Decor): the page's dots (rgb, strength),
+    // their geometry (period, solid radius, faded radius, in pixels), and a
+    // file name's shadow (rgb, offset in pixels).
+    vec4 decor_dots;
+    vec4 decor_dot_geom;
+    vec4 decor_shadow;
 } u_ui;
 
 layout(location = 0) in vec2 v_uv;
@@ -43,7 +49,7 @@ void main() {
     float bgA = (v_effect.x & 0x20000000u) != 0u ? 1.0
         : (v_effect.x & 0x40000000u) != 0u ? 0.0
         : clamp(u_ui.background_opacity, 0.0, 1.0);
-    uint effect = v_effect.x & 0x0fffffffu;
+    uint effect = v_effect.x & 0x07ffffffu;
     float progress = clamp(uintBitsToFloat(v_effect.y), 0.0, 1.0);
     uint cellCol = v_effect.w & 0xffffu;
     uint cellRow = v_effect.w >> 16;
@@ -52,7 +58,29 @@ void main() {
     // Ink over ground, both premultiplied: v_fg*a + (v_bg*bgA)*(1-a), which is
     // mix() with the ground already premultiplied. At bgA = 1 that is exactly
     // the mix(v_bg, v_fg, a) at alpha 1 this shader always wrote.
-    vec4 cell = vec4(mix(v_bg * bgA, v_fg, a), mix(bgA, 1.0, a));
+    vec3 ground = v_bg;
+    // 0x10000000: the page's ground under a pane body, dotted (lapis): a
+    // dot every period pixels, fixed to the window, under the text.
+    if ((v_effect.x & 0x10000000u) != 0u) {
+        float period = u_ui.decor_dot_geom.x;
+        vec2 d = mod(gl_FragCoord.xy, period) - 0.5 * period;
+        float dot_a = 1.0 - smoothstep(u_ui.decor_dot_geom.y, u_ui.decor_dot_geom.z, length(d));
+        ground = mix(ground, u_ui.decor_dots.rgb, u_ui.decor_dots.a * dot_a);
+    }
+    vec4 under = vec4(ground * bgA, bgA);
+    // Derivatives outside any branch: a pixel's step in the atlas and in
+    // the cell, for the shadow's offset.
+    vec2 step_uv = vec2(dFdx(v_uv.x), dFdy(v_uv.y)) * u_ui.decor_shadow.a;
+    vec2 step_cell = vec2(dFdx(v_cell_uv.x), dFdy(v_cell_uv.y)) * u_ui.decor_shadow.a;
+    // 0x08000000: a file name's letters cast a shadow down and right onto
+    // their own cell's ground (lapis), under the ink; what would fall past
+    // the cell's edge is not drawn.
+    if ((v_effect.x & 0x08000000u) != 0u) {
+        vec2 from = v_cell_uv - step_cell;
+        float s = all(greaterThanEqual(from, vec2(0.0))) ? texture(u_atlas, v_uv - step_uv).r : 0.0;
+        under = mix(under, vec4(u_ui.decor_shadow.rgb, 1.0), s);
+    }
+    vec4 cell = vec4(mix(under.rgb, v_fg, a), mix(under.a, 1.0, a));
 
     // 3 = data dissolve. Changed cells retain the frozen old cell until their
     // stable threshold, then atomically become the new cell. Exact endpoints
diff --git a/shaders/prebuilt/ui.frag.spv b/shaders/prebuilt/ui.frag.spv
index c8ee1604..d83d9c55 100644
Binary files a/shaders/prebuilt/ui.frag.spv and b/shaders/prebuilt/ui.frag.spv differ
diff --git a/shaders/prebuilt/ui.vert.glsl b/shaders/prebuilt/ui.vert.glsl
index 5551f3f1..de22adee 100644
--- a/shaders/prebuilt/ui.vert.glsl
+++ b/shaders/prebuilt/ui.vert.glsl
@@ -14,9 +14,11 @@ layout(location = 3) in vec3 a_bg;
 layout(location = 4) in vec4 a_panel_rect;
 layout(location = 5) in vec4 a_present_rect;
 // effect id, eased-progress float bits, pane serial, local row/column packed
-// into one uint. The FOUR high effect bits are flags — the frozen-old cell
-// layer, a see-through cell background, an opaque block-cursor fill and a
-// soft shadow (decor.frag.glsl) — so the id is what is left below them; integer transport preserves the exact
+// into one uint. The FIVE high effect bits are flags — the frozen-old cell
+// layer, a see-through cell background, an opaque block-cursor fill, a soft
+// shadow (decor.frag.glsl) or dotted page ground (ui.frag.glsl), and a
+// checker (decor) or a file name's shadow (ui) — so the id is what is left
+// below them; integer transport preserves the exact
 // cross-backend hash.
 layout(location = 6) in uvec4 a_effect;
 // A clip rectangle in target pixels (x0, y0, x1, y1): the fragment shader
@@ -61,7 +63,7 @@ void main() {
         v_cell_uv = vec2(0.0, 1.0);
     }
 
-    uint effect = a_effect.x & 0x0fffffffu;
+    uint effect = a_effect.x & 0x07ffffffu;
     if (effect == 1u || effect == 2u || effect == 5u) {
         // NDC y points up, so a top-left/bottom-right box has a NEGATIVE y
         // delta. Preserve that sign or every local y is mirrored/outside.
diff --git a/shaders/prebuilt/ui.vert.spv b/shaders/prebuilt/ui.vert.spv
index b1e87ec1..af5b0738 100644
Binary files a/shaders/prebuilt/ui.vert.spv and b/shaders/prebuilt/ui.vert.spv differ
diff --git a/shaders/ui.frag.glsl b/shaders/ui.frag.glsl
index dca224ba..62dbbfa2 100644
--- a/shaders/ui.frag.glsl
+++ b/shaders/ui.frag.glsl
@@ -10,6 +10,12 @@
 layout(set = 2, binding = 0) uniform sampler2D u_atlas;
 layout(std140, set = 3, binding = 0) uniform UiUniforms {
     float background_opacity;
+    // A theme's ornament (colors.Decor): the page's dots (rgb, strength),
+    // their geometry (period, solid radius, faded radius, in pixels), and a
+    // file name's shadow (rgb, offset in pixels).
+    vec4 decor_dots;
+    vec4 decor_dot_geom;
+    vec4 decor_shadow;
 } u_ui;
 
 layout(location = 0) in vec2 v_uv;
@@ -43,7 +49,7 @@ void main() {
     float bgA = (v_effect.x & 0x20000000u) != 0u ? 1.0
         : (v_effect.x & 0x40000000u) != 0u ? 0.0
         : clamp(u_ui.background_opacity, 0.0, 1.0);
-    uint effect = v_effect.x & 0x0fffffffu;
+    uint effect = v_effect.x & 0x07ffffffu;
     float progress = clamp(uintBitsToFloat(v_effect.y), 0.0, 1.0);
     uint cellCol = v_effect.w & 0xffffu;
     uint cellRow = v_effect.w >> 16;
@@ -52,7 +58,29 @@ void main() {
     // Ink over ground, both premultiplied: v_fg*a + (v_bg*bgA)*(1-a), which is
     // mix() with the ground already premultiplied. At bgA = 1 that is exactly
     // the mix(v_bg, v_fg, a) at alpha 1 this shader always wrote.
-    vec4 cell = vec4(mix(v_bg * bgA, v_fg, a), mix(bgA, 1.0, a));
+    vec3 ground = v_bg;
+    // 0x10000000: the page's ground under a pane body, dotted (lapis): a
+    // dot every period pixels, fixed to the window, under the text.
+    if ((v_effect.x & 0x10000000u) != 0u) {
+        float period = u_ui.decor_dot_geom.x;
+        vec2 d = mod(gl_FragCoord.xy, period) - 0.5 * period;
+        float dot_a = 1.0 - smoothstep(u_ui.decor_dot_geom.y, u_ui.decor_dot_geom.z, length(d));
+        ground = mix(ground, u_ui.decor_dots.rgb, u_ui.decor_dots.a * dot_a);
+    }
+    vec4 under = vec4(ground * bgA, bgA);
+    // Derivatives outside any branch: a pixel's step in the atlas and in
+    // the cell, for the shadow's offset.
+    vec2 step_uv = vec2(dFdx(v_uv.x), dFdy(v_uv.y)) * u_ui.decor_shadow.a;
+    vec2 step_cell = vec2(dFdx(v_cell_uv.x), dFdy(v_cell_uv.y)) * u_ui.decor_shadow.a;
+    // 0x08000000: a file name's letters cast a shadow down and right onto
+    // their own cell's ground (lapis), under the ink; what would fall past
+    // the cell's edge is not drawn.
+    if ((v_effect.x & 0x08000000u) != 0u) {
+        vec2 from = v_cell_uv - step_cell;
+        float s = all(greaterThanEqual(from, vec2(0.0))) ? texture(u_atlas, v_uv - step_uv).r : 0.0;
+        under = mix(under, vec4(u_ui.decor_shadow.rgb, 1.0), s);
+    }
+    vec4 cell = vec4(mix(under.rgb, v_fg, a), mix(under.a, 1.0, a));
 
     // 3 = data dissolve. Changed cells retain the frozen old cell until their
     // stable threshold, then atomically become the new cell. Exact endpoints
diff --git a/shaders/ui.vert.glsl b/shaders/ui.vert.glsl
index 5551f3f1..de22adee 100644
--- a/shaders/ui.vert.glsl
+++ b/shaders/ui.vert.glsl
@@ -14,9 +14,11 @@ layout(location = 3) in vec3 a_bg;
 layout(location = 4) in vec4 a_panel_rect;
 layout(location = 5) in vec4 a_present_rect;
 // effect id, eased-progress float bits, pane serial, local row/column packed
-// into one uint. The FOUR high effect bits are flags — the frozen-old cell
-// layer, a see-through cell background, an opaque block-cursor fill and a
-// soft shadow (decor.frag.glsl) — so the id is what is left below them; integer transport preserves the exact
+// into one uint. The FIVE high effect bits are flags — the frozen-old cell
+// layer, a see-through cell background, an opaque block-cursor fill, a soft
+// shadow (decor.frag.glsl) or dotted page ground (ui.frag.glsl), and a
+// checker (decor) or a file name's shadow (ui) — so the id is what is left
+// below them; integer transport preserves the exact
 // cross-backend hash.
 layout(location = 6) in uvec4 a_effect;
 // A clip rectangle in target pixels (x0, y0, x1, y1): the fragment shader
@@ -61,7 +63,7 @@ void main() {
         v_cell_uv = vec2(0.0, 1.0);
     }
 
-    uint effect = a_effect.x & 0x0fffffffu;
+    uint effect = a_effect.x & 0x07ffffffu;
     if (effect == 1u || effect == 2u || effect == 5u) {
         // NDC y points up, so a top-left/bottom-right box has a NEGATIVE y
         // delta. Preserve that sign or every local y is mirrored/outside.
diff --git a/src/colors.zig b/src/colors.zig
index 4a18bba9..b44e84f9 100644
--- a/src/colors.zig
+++ b/src/colors.zig
@@ -123,6 +123,42 @@ pub fn mix(a: [3]u8, b: [3]u8) [3]u8 {
     return out;
 }
 
+/// A theme's ornament, drawn by a pixel shell inside the chrome it already
+/// has (docs/render-pipeline.md §10: no gaps between panes): the lapis
+/// theme's. Sizes are logical pixels. None of it touches a focus indicator:
+/// the dots lie on the page's own ground, the checker in the scroll track
+/// (never its thumb), a tag's plaque inside its band beside its grip (and
+/// the focused one only the more striking), and the shadow under a file
+/// name's own letters.
+pub const Decor = struct {
+    /// A dot grid on the page's ground, `page_dot_alpha` of 255 strong, a
+    /// dot one logical pixel across (fading out by a pixel and a half) every
+    /// `page_dot_px`, fixed to the window.
+    page_dots: ?[3]u8 = null,
+    page_dot_alpha: u8 = 0x22,
+    page_dot_px: u8 = 22,
+    /// A checker in the scroll track, squares of `rail_checker_px`, this
+    /// colour and the track's.
+    rail_checker: ?[3]u8 = null,
+    rail_checker_px: u8 = 3,
+    /// Every tag drawn as a raised plaque inside its own band (the site's
+    /// trail and title bars): a `tag_border` frame round the text, a hard
+    /// `tag_shadow` offset down and right by `tag_shadow_px`, both within
+    /// the band's rows and columns, never past them; the focused pane's
+    /// plaque striped `tag_stripe` and the tag's ground, `tag_stripe_px`
+    /// each, its words on plates of the ground. Column and workspace tags
+    /// take a quieter one (a one-pixel frame, a shadow of two, no stripes).
+    tag_border: ?[3]u8 = null,
+    tag_border_px: u8 = 2,
+    tag_shadow: ?[3]u8 = null,
+    tag_shadow_px: u8 = 5,
+    tag_stripe: ?[3]u8 = null,
+    tag_stripe_px: u8 = 2,
+    /// The file name's offset shadow, down and right, in a pane's tag.
+    title_shadow: ?[3]u8 = null,
+    title_shadow_px: u8 = 2,
+};
+
 pub const Theme = struct {
     name: []const u8,
     bg: ?[3]u8,
@@ -188,6 +224,8 @@ pub const Theme = struct {
     /// in pixels at a 17px tagline, the thumb one narrower (acme's 12px
     /// Scrollwid, the default).
     rail_px: ?u8 = null,
+    /// A pixel shell's ornament (Decor): lapis's.
+    decor: ?Decor = null,
 };
 
 const curated = struct {
@@ -209,6 +247,7 @@ const curated = struct {
     pub const helix = @import("themes/helix.zig");
     pub const dark = @import("themes/dark.zig");
     pub const acme = @import("themes/acme.zig");
+    pub const lapis = @import("themes/lapis.zig");
 };
 
 fn fold(comptime C: type) [@typeInfo(C).@"struct".decls.len]Theme {
@@ -219,7 +258,15 @@ fn fold(comptime C: type) [@typeInfo(C).@"struct".decls.len]Theme {
             var t: Theme = undefined;
             const source = @field(C, d.name).theme;
             for (@typeInfo(Theme).@"struct".fields) |f| {
-                @field(t, f.name) = if (@hasField(@TypeOf(source), f.name))
+                @field(t, f.name) = if (f.type == ?Decor and @hasField(@TypeOf(source), f.name)) decor: {
+                    // A nested literal is folded field by field too.
+                    var decor: Decor = .{};
+                    const given = @field(source, f.name);
+                    for (@typeInfo(Decor).@"struct".fields) |g| if (@hasField(@TypeOf(given), g.name)) {
+                        @field(decor, g.name) = @field(given, g.name);
+                    };
+                    break :decor decor;
+                } else if (@hasField(@TypeOf(source), f.name))
                     @field(source, f.name)
                 else if (f.default_value_ptr) |ptr|
                     @as(*const f.type, @ptrCast(@alignCast(ptr))).*
diff --git a/src/detached/wire.zig b/src/detached/wire.zig
index 53a1a70d..9f9c716a 100644
--- a/src/detached/wire.zig
+++ b/src/detached/wire.zig
@@ -13,7 +13,7 @@ pub const version: u16 = 8;
 
 /// The Chrome palette is carried field by field as its declaration lists
 /// them, so any change to it changes the wire: bump `version`, then this.
-const chrome_layout: u64 = 0xc91196fcdef144e2;
+const chrome_layout: u64 = 0xf852cb229ae38f51;
 comptime {
     @setEvalBranchQuota(10_000);
     var hash = std.hash.Fnv1a_64.init();
diff --git a/src/draw.zig b/src/draw.zig
index b8cf4e7d..5f14ae21 100644
--- a/src/draw.zig
+++ b/src/draw.zig
@@ -470,7 +470,24 @@ pub fn render(p: *Pardes, arena: std.mem.Allocator) !*Surface {
         .grip_dirty = boxDirty(p),
         .tag_rule = p.theme().tag_rule,
         .rail_px = @intCast(@min(255, @as(u32, p.theme().rail_px orelse 12) * p.settings.grip_width / 100)),
+        .name_ink = chrome.tag_name_fg,
+        .active_name_ink = if (p.settings.focus_tint) chrome.tag_active_name_fg else chrome.tag_name_fg,
     };
+    if (p.theme().decor) |decor| {
+        s.chrome.decor_dots = decor.page_dots;
+        s.chrome.decor_dot_alpha = decor.page_dot_alpha;
+        s.chrome.decor_dot_px = decor.page_dot_px;
+        s.chrome.decor_checker = decor.rail_checker;
+        s.chrome.decor_checker_px = decor.rail_checker_px;
+        s.chrome.decor_box_border = decor.tag_border;
+        s.chrome.decor_box_border_px = decor.tag_border_px;
+        s.chrome.decor_box_shadow = decor.tag_shadow;
+        s.chrome.decor_box_shadow_px = decor.tag_shadow_px;
+        s.chrome.decor_box_stripe = decor.tag_stripe;
+        s.chrome.decor_box_stripe_px = decor.tag_stripe_px;
+        s.chrome.decor_title = decor.title_shadow;
+        s.chrome.decor_title_px = decor.title_shadow_px;
+    }
     place(p, s);
     // Separators have their own role; a scrollbar need not frame the page.
     const whole = s.regions[0].rect;
diff --git a/src/gui/gui.zig b/src/gui/gui.zig
index bde9aecd..092bb3bf 100644
--- a/src/gui/gui.zig
+++ b/src/gui/gui.zig
@@ -507,6 +507,12 @@ const clear_bg_bit: u32 = 0x4000_0000;
 const opaque_bg_bit: u32 = 0x2000_0000;
 /// Decor that is a soft shadow, not a flat fill (decor.frag.glsl).
 const soft_shadow_bit: u32 = 0x1000_0000;
+/// Decor that is a checker (decor.frag.glsl).
+const checker_bit: u32 = 0x0800_0000;
+/// A cell on the page's ground under the theme's dots, and a file name's
+/// cell that casts the theme's shadow (ui.frag.glsl, Chrome.decor_*).
+const dotted_bit: u32 = 0x1000_0000;
+const title_bit: u32 = 0x0800_0000;
 
 const SavedImagePlace = struct {
     key: pardes.ImageCacheKey,
@@ -1787,6 +1793,10 @@ const Gui = struct {
     device: *c.SDL_GPUDevice,
     swapchain_format: c.SDL_GPUTextureFormat,
     pipeline: *c.SDL_GPUGraphicsPipeline,
+    /// The cell pipeline, blending premultiplied over what is drawn under:
+    /// for a frame with a theme's tag plaques, whose blank tag cells let
+    /// them show (tagPlaques).
+    pipeline_over: *c.SDL_GPUGraphicsPipeline,
     decor_pipeline: *c.SDL_GPUGraphicsPipeline,
     overlay_pipeline: *c.SDL_GPUGraphicsPipeline,
     image_pipeline: *c.SDL_GPUGraphicsPipeline,
@@ -2068,6 +2078,9 @@ const Group = struct {
     image_count: u32 = 0,
     decor_start: u32 = 0,
     decor_count: u32 = 0,
+    /// The first `under_count` of the group's decor are drawn before its
+    /// cells, under them (a theme's tag plaques, whose cells let them show).
+    under_count: u32 = 0,
 };
 
 /// The frame's draw groups, bottom to top: tier 0 (the page and the panes
@@ -2455,6 +2468,7 @@ fn runNative(init: std.process.Init, opts_in: pardes.Options, attach: ?[]const u
     const atlas_xfer = c.SDL_CreateGPUTransferBuffer(device, &ax_info) orelse return error.GpuCreate;
 
     const pipeline = try makePipeline(device, swapchain_format, frag_spv, 1, std.mem.zeroes(c.SDL_GPUColorTargetBlendState));
+    const pipeline_over = try makePipeline(device, swapchain_format, frag_spv, 1, premultipliedBlend());
     const decor_pipeline = try makePipeline(device, swapchain_format, decor_frag_spv, 0, backgroundLayerBlend());
     const overlay_pipeline = try makeOverlayPipeline(device, swapchain_format);
     const image_pipeline = try makeImagePipeline(device, swapchain_format);
@@ -2485,6 +2499,7 @@ fn runNative(init: std.process.Init, opts_in: pardes.Options, attach: ?[]const u
         .device = device,
         .swapchain_format = swapchain_format,
         .pipeline = pipeline,
+        .pipeline_over = pipeline_over,
         .decor_pipeline = decor_pipeline,
         .overlay_pipeline = overlay_pipeline,
         .image_pipeline = image_pipeline,
@@ -2523,6 +2538,7 @@ fn runNative(init: std.process.Init, opts_in: pardes.Options, attach: ?[]const u
     // regrown to; the image ones are released below.
     defer {
         c.SDL_ReleaseGPUGraphicsPipeline(device, g.pipeline);
+        c.SDL_ReleaseGPUGraphicsPipeline(device, g.pipeline_over);
         c.SDL_ReleaseGPUGraphicsPipeline(device, g.decor_pipeline);
         c.SDL_ReleaseGPUGraphicsPipeline(device, g.overlay_pipeline);
         c.SDL_ReleaseGPUTexture(device, g.atlas_tex);
@@ -5418,6 +5434,20 @@ fn renderFrame(
     defer if (building) build_zone.end();
     const layout = fixedCellLayout(g);
     const chrome = &surface.chrome;
+    cell_decor = CellDecor.of(chrome);
+    // Plaques need an opaque window: with WindowOpacity under 100 the cells
+    // are drawn as they are, and the plaques not at all.
+    cell_decor.plaques_off = backgroundOpacity(g.applied_window_opacity) < 1;
+    if (chrome.decor_box_border != null and !cell_decor.plaques_off) {
+        cell_decor.grounds = .{ chrome.tag_bg, chrome.tag_focus_bg };
+        for (surface.regionList()) |region| {
+            if (region.kind != .tag and region.kind != .column_tag and region.kind != .workspace_tag) continue;
+            if (cell_decor.nplaques == cell_decor.plaques.len) break;
+            const plaque = plaqueBox(g, chrome, surface.regionList(), region, layout, win_w, win_h) orelse continue;
+            cell_decor.plaques[cell_decor.nplaques] = plaque.band;
+            cell_decor.nplaques += 1;
+        }
+    }
     var groups = makeGroups(surface.panelTracks(), surface.hasPanelDiff());
     // Cursors stand still while panes move, as they always have; while the
     // focused one glides or blinks, it is the overlay's quad instead. One
@@ -5696,9 +5726,16 @@ fn renderFrame(
     const whole = c.SDL_Rect{ .x = 0, .y = 0, .w = @intCast(sw), .h = @intCast(sh) };
     const decor_base = cell_total + shifted;
     for (groups.items[0..groups.len], 0..) |group, index| {
+        if (group.under_count != 0 and g.vbuf != null) {
+            c.SDL_BindGPUGraphicsPipeline(rp, g.decor_pipeline);
+            pushLayerOpacity(cmd, rp, background_opacity);
+            const binding = c.SDL_GPUBufferBinding{ .buffer = g.vbuf.?, .offset = (decor_base + group.decor_start) * @sizeOf(CellInstance) };
+            c.SDL_BindGPUVertexBuffers(rp, 0, &binding, 1);
+            c.SDL_DrawGPUPrimitives(rp, 6, group.under_count, 0, 0);
+        }
         const has_shifted = index == 0 and shifted != 0;
         if ((group.cell_count != 0 or has_shifted) and g.vbuf != null) {
-            c.SDL_BindGPUGraphicsPipeline(rp, g.pipeline);
+            c.SDL_BindGPUGraphicsPipeline(rp, if (cell_decor.nplaques != 0) g.pipeline_over else g.pipeline);
             const samp_binding = c.SDL_GPUTextureSamplerBinding{ .texture = g.atlas_tex, .sampler = g.atlas_sampler };
             c.SDL_BindGPUFragmentSamplers(rp, 0, &samp_binding, 1);
             if (group.cell_count != 0) {
@@ -5716,13 +5753,13 @@ fn renderFrame(
             }
         }
         if (group.image_count != 0) drawNativeImagesGpu(g, rp, surface, group, whole);
-        if (group.decor_count != 0 and g.vbuf != null) {
+        if (group.decor_count > group.under_count and g.vbuf != null) {
             c.SDL_BindGPUGraphicsPipeline(rp, g.decor_pipeline);
             // Ink keeps its colour at any WindowOpacity.
             pushLayerOpacity(cmd, rp, if (index == groups.ink) 1 else background_opacity);
-            const binding = c.SDL_GPUBufferBinding{ .buffer = g.vbuf.?, .offset = (decor_base + group.decor_start) * @sizeOf(CellInstance) };
+            const binding = c.SDL_GPUBufferBinding{ .buffer = g.vbuf.?, .offset = (decor_base + group.decor_start + group.under_count) * @sizeOf(CellInstance) };
             c.SDL_BindGPUVertexBuffers(rp, 0, &binding, 1);
-            c.SDL_DrawGPUPrimitives(rp, 6, group.decor_count, 0, 0);
+            c.SDL_DrawGPUPrimitives(rp, 6, group.decor_count - group.under_count, 0, 0);
         }
     }
     drawOverlayGpu(g, cmd, rp, overlay_count);
@@ -6024,6 +6061,9 @@ fn emitTagLayer(g: *Gui, instances: [*]CellInstance, next: *u32, layer: *const p
         const y = layer.viewport.y + @as(u16, @intCast(index));
         const top = @as(f32, @floatFromInt(y)) * bh;
         emitInstance(g, instances, next.*, 0, y, .{ .w = band_right - left, .h = bh, .x_off = left, .y_off = slide }, win_w, win_h, track, .body, (&background)[0..1], 0, null, old_layer, false, page);
+        // A theme's plaque is drawn under the band: the band's own ground
+        // lets it show (tagPlaques).
+        if (cell_decor.nplaques != 0 and cell_decor.inPlaque(left + 0.5, top + 0.5)) instances[next.*].effect |= clear_bg_bit;
         if (slide != 0) clipInstanceTop(&instances[next.*], top, win_h);
         next.* += 1;
         const cells = layer.cells[index * layer.cols ..][0..layer.cols];
@@ -6229,6 +6269,10 @@ fn emitSurfaceCell(
         // this underlay at tagline height leaves page-colored gutters between
         // adjacent workspace, column and pane tags at TaglineSize < 100.
         emitInstance(g, instances, next.*, col, row, body_layout, win_w, win_h, track, .body, (&band_base)[0..1], 0, null, old_layer, false, page);
+        // Over a theme's plaque (not a grip's button) the underlay lets it
+        // show (tagPlaques).
+        if (cell_decor.nplaques != 0 and !here.grip and cell_decor.inPlaque((@as(f32, @floatFromInt(col)) + 0.5) * body_layout.w + body_layout.x_off, @as(f32, @floatFromInt(row)) * body_layout.h + body_layout.y_off + 0.5))
+            instances[next.*].effect |= clear_bg_bit;
         next.* += 1;
         // Tag glyphs keep their font size inside a full physical-width grip.
         // A pane's grip cells are the cell shells' form (a dirty `*`): the
@@ -6553,6 +6597,21 @@ fn emitInstance(
     // A block cursor is foreground UI ink, even though its color is carried
     // in the reversed cell background. Keep it visible at WindowOpacity 0.
     if (is_cursor) instances[idx].effect |= opaque_bg_bit;
+    // The theme's ornament (cell_decor): dots on the page's own ground, a
+    // shadow under a file name's letters. Never on a cursor.
+    if (!is_cursor) {
+        // A blank cell on a tag's ground inside a plaque: the plaque shows.
+        if (cell_decor.nplaques != 0 and resolved.role == .tagline and cellCodepoint(&line[at]) == ' ' and
+            (std.mem.eql(u8, &resolved.bg, &cell_decor.grounds[0]) or std.mem.eql(u8, &resolved.bg, &cell_decor.grounds[1])) and
+            (cell_decor.inPlaque(px0 + 0.5, py0 + 0.5) or cell_decor.inPlaque(px0 + layout.w - 0.5, py0 + 0.5)))
+            instances[idx].effect |= clear_bg_bit;
+        if (cell_decor.dots) |dotted| {
+            if (!resolved.clear_bg and std.mem.eql(u8, &resolved.bg, &dotted)) instances[idx].effect |= dotted_bit;
+        }
+        if (cell_decor.title) |inks| {
+            if (resolved.role == .tagline and (std.mem.eql(u8, &resolved.fg, &inks[0]) or std.mem.eql(u8, &resolved.fg, &inks[1]))) instances[idx].effect |= title_bit;
+        }
+    }
 }
 
 test "block cursor alone overrides transparent cell background" {
@@ -6569,6 +6628,107 @@ test "block cursor alone overrides transparent cell background" {
     }
 }
 
+test "lapis dots only the page's own ground and shadows only a file name, never a cursor" {
+    var g: Gui = undefined;
+    g.words = .{};
+    g.cell_w = 10;
+    g.cell_h = 20;
+    g.tagline_width = 8;
+    g.tagline_height = 16;
+    g.space_slot = .{ .u = 0, .v = 0 };
+    const page: [3]u8 = .{ 0x0a, 0x10, 0x30 };
+    const name: [3]u8 = .{ 0xe8, 0xc4, 0x6a };
+    var chrome: pardes.Chrome = .{ .page = page, .decor_dots = .{ 1, 2, 3 }, .decor_dot_alpha = 0x22, .decor_title = .{ 4, 5, 6 }, .name_ink = name, .active_name_ink = name };
+    cell_decor = CellDecor.of(&chrome);
+    defer cell_decor = .{};
+    const on_page: pardes.Cell = .{ .default = false, .style = .{ .fg = .{ .rgb = .{ 200, 200, 200 } }, .bg = .{ .rgb = page } } };
+    const selected: pardes.Cell = .{ .default = false, .style = .{ .fg = .{ .rgb = .{ 0, 0, 0 } }, .bg = .{ .rgb = name } } };
+    const title: pardes.Cell = .{ .default = false, .style = .{ .fg = .{ .rgb = name }, .bg = .{ .rgb = .{ 0x0f, 0x1a, 0x4a } }, .font_role = .tagline } };
+    const plain_tag: pardes.Cell = .{ .default = false, .style = .{ .fg = .{ .rgb = .{ 0x9a, 0xa6, 0xd9 } }, .bg = .{ .rgb = .{ 0x0f, 0x1a, 0x4a } }, .font_role = .tagline } };
+    var instances: [1]CellInstance = undefined;
+    const Case = struct { cell: pardes.Cell, role: pardes.FontRole, cursor: bool, dotted: bool, shadowed: bool };
+    for ([_]Case{
+        .{ .cell = on_page, .role = .body, .cursor = false, .dotted = true, .shadowed = false },
+        .{ .cell = on_page, .role = .body, .cursor = true, .dotted = false, .shadowed = false },
+        .{ .cell = selected, .role = .body, .cursor = false, .dotted = false, .shadowed = false },
+        .{ .cell = title, .role = .tagline, .cursor = false, .dotted = false, .shadowed = true },
+        .{ .cell = title, .role = .tagline, .cursor = true, .dotted = false, .shadowed = false },
+        .{ .cell = plain_tag, .role = .tagline, .cursor = false, .dotted = false, .shadowed = false },
+    }) |case| {
+        emitInstance(&g, &instances, 0, 0, 0, fixedCellLayout(&g), 800, 480, null, case.role, (&case.cell)[0..1], 0, null, false, case.cursor, Ground.opaqueRgb(page));
+        try std.testing.expectEqual(case.dotted, instances[0].effect & dotted_bit != 0);
+        try std.testing.expectEqual(case.shadowed, instances[0].effect & title_bit != 0);
+    }
+    // A theme without decor marks nothing.
+    chrome = .{ .page = page };
+    cell_decor = CellDecor.of(&chrome);
+    emitInstance(&g, &instances, 0, 0, 0, fixedCellLayout(&g), 800, 480, null, .body, (&on_page)[0..1], 0, null, false, false, Ground.opaqueRgb(page));
+    try std.testing.expectEqual(@as(u32, 0), instances[0].effect & (dotted_bit | title_bit));
+}
+
+test "lapis plaques stay in their tag's band, clear of every grip; only the focused one is striped" {
+    const gpa = std.testing.allocator;
+    const core = try pardes.Pardes.init(gpa, .{ .cols = 80, .rows = 24 });
+    defer core.deinit();
+    _ = try core.newShell(1, "");
+    try std.testing.expect(pardes.layout.splitColumn(core, 0, 1, false));
+    try std.testing.expect(core.executeBuiltinLine(0, "Theme lapis"));
+    for (0..40) |_| core.update(.tick);
+    pardes.test_api.sync(core);
+    const s = try core.render(core.scratch.allocator());
+    try std.testing.expect(s.chrome.decor_box_border != null and s.chrome.decor_checker != null and s.chrome.decor_dots != null and s.chrome.decor_title != null);
+    var g: Gui = undefined;
+    g.decor = .empty;
+    defer g.decor.deinit(gpa);
+    g.cell_w = 16;
+    g.cell_h = 32;
+    g.tagline_width = 12;
+    g.tagline_height = 22;
+    display_scale = 1;
+    var groups = makeGroups(&.{}, false);
+    try buildDecor(&g, gpa, s, &groups, fixedCellLayout(&g), 1280, 768, true);
+    const layout = fixedCellLayout(&g);
+    const under = g.decor.items[groups.items[0].decor_start..][0..groups.items[0].under_count];
+    try std.testing.expect(under.len != 0);
+    var stripes: usize = 0;
+    var shadows: usize = 0;
+    for (under) |item| {
+        const r: [4]f32 = .{ (item.x0 + 1) / 2 * 1280, (1 - item.y0) / 2 * 768, (item.x1 + 1) / 2 * 1280, (1 - item.y1) / 2 * 768 };
+        // Inside one tag's band, whole: never on a body, a grip or the
+        // next pane.
+        const home = for (s.regionList()) |region| {
+            if (region.kind != .tag and region.kind != .column_tag and region.kind != .workspace_tag) continue;
+            const band = plaqueBox(&g, &s.chrome, s.regionList(), region, layout, 1280, 768) orelse continue;
+            if (r[0] >= band.band[0] - 0.01 and r[1] >= band.band[1] - 0.01 and r[2] <= band.band[2] + 0.01 and r[3] <= band.band[3] + 0.01) break region;
+        } else return error.PlaqueOutsideItsBand;
+        for (s.regionList()) |grip| {
+            if (grip.kind != .grip and grip.kind != .column_grip) continue;
+            const gx0 = @as(f32, @floatFromInt(grip.rect.x)) * 16;
+            const gx1 = @as(f32, @floatFromInt(grip.rect.x + grip.rect.w)) * 16;
+            const gy0 = @as(f32, @floatFromInt(grip.rect.y)) * 32;
+            const gy1 = @as(f32, @floatFromInt(grip.rect.y + grip.rect.h)) * 32;
+            try std.testing.expect(r[2] <= gx0 + 0.01 or r[0] >= gx1 - 0.01 or r[3] <= gy0 + 0.01 or r[1] >= gy1 - 0.01);
+        }
+        if (item.effect & checker_bit != 0) {
+            try std.testing.expect(home.kind == .tag and home.active);
+            stripes += 1;
+        }
+        const rgb: [3]u8 = .{ @intFromFloat(@round(item.br * 255)), @intFromFloat(@round(item.bg * 255)), @intFromFloat(@round(item.bb * 255)) };
+        if (std.mem.eql(u8, &rgb, &s.chrome.decor_box_shadow.?)) shadows += 1;
+    }
+    try std.testing.expectEqual(@as(usize, 1), stripes);
+    try std.testing.expect(shadows >= 2);
+    // The scroll track is chequered.
+    var checkers: usize = 0;
+    for (g.decor.items[groups.items[0].decor_start + groups.items[0].under_count ..]) |item| checkers += @intFromBool(item.effect & checker_bit != 0);
+    try std.testing.expect(checkers >= 1);
+    // No other theme draws any of it.
+    try std.testing.expect(core.executeBuiltinLine(0, "Theme forge"));
+    for (0..40) |_| core.update(.tick);
+    const plain = try core.render(core.scratch.allocator());
+    try std.testing.expect(plain.chrome.decor_box_border == null and plain.chrome.decor_checker == null and plain.chrome.decor_dots == null and plain.chrome.decor_title == null);
+}
+
 fn cellCodepoint(cell: *const pardes.Cell) u32 {
     const grapheme = cell.grapheme();
     return if (cell.default or grapheme.len == 0) ' ' else firstCp(grapheme);
@@ -7352,6 +7512,20 @@ fn makePipeline(device: *c.SDL_GPUDevice, color_format: c.SDL_GPUTextureFormat,
     return c.SDL_CreateGPUGraphicsPipeline(device, &info) orelse error.GpuCreate;
 }
 
+/// Premultiplied over: an opaque cell writes itself exactly, a see-through
+/// one only its ink.
+fn premultipliedBlend() c.SDL_GPUColorTargetBlendState {
+    var blend = std.mem.zeroes(c.SDL_GPUColorTargetBlendState);
+    blend.src_color_blendfactor = c.SDL_GPU_BLENDFACTOR_ONE;
+    blend.dst_color_blendfactor = c.SDL_GPU_BLENDFACTOR_ONE_MINUS_SRC_ALPHA;
+    blend.color_blend_op = c.SDL_GPU_BLENDOP_ADD;
+    blend.src_alpha_blendfactor = c.SDL_GPU_BLENDFACTOR_ONE;
+    blend.dst_alpha_blendfactor = c.SDL_GPU_BLENDFACTOR_ONE_MINUS_SRC_ALPHA;
+    blend.alpha_blend_op = c.SDL_GPU_BLENDOP_ADD;
+    blend.enable_blend = true;
+    return blend;
+}
+
 fn backgroundLayerBlend() c.SDL_GPUColorTargetBlendState {
     var blend = std.mem.zeroes(c.SDL_GPUColorTargetBlendState);
     blend.src_color_blendfactor = c.SDL_GPU_BLENDFACTOR_SRC_ALPHA;
@@ -7742,6 +7916,29 @@ fn addDecor(g: *Gui, gpa: std.mem.Allocator, x0_in: f32, y0_in: f32, x1_in: f32,
     try g.decor.append(gpa, instance);
 }
 
+/// A checker (decor.frag.glsl): squares of `px` window pixels in `a` and
+/// `b` from the quad's corner (lapis's scroll track); `stripes`, bands of
+/// `px` across it instead (lapis's focused title bar), `a` first.
+fn addChecker(g: *Gui, gpa: std.mem.Allocator, x0: f32, y0: f32, x1: f32, y1: f32, a: [3]u8, b: [3]u8, px: f32, track: ?pardes.animation.Track, win_w: f32, win_h: f32) !void {
+    return addPattern(g, gpa, x0, y0, x1, y1, a, b, px, false, track, win_w, win_h);
+}
+
+fn addPattern(g: *Gui, gpa: std.mem.Allocator, x0: f32, y0: f32, x1: f32, y1: f32, a: [3]u8, b: [3]u8, px: f32, stripes: bool, track: ?pardes.animation.Track, win_w: f32, win_h: f32) !void {
+    const first = g.decor.items.len;
+    try addDecor(g, gpa, x0, y0, x1, y1, a, 1, track, win_w, win_h);
+    if (g.decor.items.len == first) return;
+    const instance = &g.decor.items[first];
+    instance.u0 = px;
+    instance.u1 = px;
+    instance.v0 = if (stripes) 1 else 0;
+    instance.v1 = if (stripes) 1 else 0;
+    instance.fr = @as(f32, @floatFromInt(b[0])) / 255.0;
+    instance.fg = @as(f32, @floatFromInt(b[1])) / 255.0;
+    instance.fb = @as(f32, @floatFromInt(b[2])) / 255.0;
+    instance.effect |= checker_bit;
+}
+
+
 /// How a lift of 0 to 1 stands off the page: the shadow's blur and offset
 /// in cell heights, and its darkest, where it leaves the caster's edge.
 /// Within §8.2's budget: sigma 0.4-0.8 cell, at most 30% darker at the edge.
@@ -8062,6 +8259,13 @@ fn buildDecor(g: *Gui, gpa: std.mem.Allocator, surface: *const pardes.Surface, g
     for (groups.items[0..groups.len], 0..) |*group, index| {
         group.decor_start = @intCast(g.decor.items.len);
         defer group.decor_count = @as(u32, @intCast(g.decor.items.len)) - group.decor_start;
+        // Under the cells: a theme's tag plaques, this group's panes' (and
+        // the column and workspace tags with the still ones).
+        if (index <= groups.tracks) {
+            const closing = if (group.track) |active| active.phase == .closing else false;
+            try tagPlaques(g, gpa, if (closing) surface.previous_regions else regions, groups, index, chrome, layout, win_w, win_h, group.track);
+        }
+        group.under_count = @as(u32, @intCast(g.decor.items.len)) - group.decor_start;
         // The grips' buttons before any rule: the rules over their rows cut
         // them, and the band round them never covers a rule.
         if (index <= groups.tracks) {
@@ -8226,7 +8430,10 @@ fn paneDecor(g: *Gui, gpa: std.mem.Allocator, regions: []const pardes.Region, gr
         // the track edges it.
         const column = scrollColumn(g, chrome, rail.rect.x, layout);
         try addDecor(g, gpa, x0, y0, x0 + layout.w, y1, page, 1, track, win_w, win_h);
-        try addDecor(g, gpa, column[0], y0, column[1], y1, chrome.scroll_track, 1, track, win_w, win_h);
+        if (chrome.decor_checker) |gold|
+            try addChecker(g, gpa, column[0], y0, column[1], y1, chrome.scroll_track, gold, dp(@floatFromInt(@max(1, chrome.decor_checker_px))), track, win_w, win_h)
+        else
+            try addDecor(g, gpa, column[0], y0, column[1], y1, chrome.scroll_track, 1, track, win_w, win_h);
         if (rail.thumb_h != 0) {
             const thumb_y0 = @as(f32, @floatFromInt(rail.rect.y + rail.thumb_y)) * layout.h;
             const thumb_y1 = if (rail.thumb_y + rail.thumb_h == rail.rect.h) y1 else @as(f32, @floatFromInt(rail.rect.y + rail.thumb_y + rail.thumb_h)) * layout.h;
@@ -8269,11 +8476,126 @@ fn updateDisplayScale(window: *c.SDL_Window) void {
     display_scale = std.math.clamp(display_scale, 1, 4);
 }
 
+/// A theme's ornament as the cell shader draws it (Chrome.decor_*), for the
+/// frame being built: renderFrame sets it, writing a cell marks the cells
+/// it falls on, and pushLayerOpacity hands the shader its colours and
+/// sizes. ponytail: one window per process, as display_scale.
+var cell_decor: CellDecor = .{};
+const CellDecor = struct {
+    /// The page's ground, when the theme dots it.
+    dots: ?[3]u8 = null,
+    /// A file name's inks in a tag, when the theme shadows it.
+    title: ?[2][3]u8 = null,
+    /// UiUniforms after background_opacity (ui.frag.glsl): the dots' colour
+    /// and strength, their period and radii, the shadow's colour and offset.
+    uniforms: [12]f32 = @splat(0),
+    /// The tag plaques' bands (window pixels) and the tag grounds: a blank
+    /// tag cell there lets its plaque show through (tagPlaques).
+    plaques: [pardes.MAX_TAG_LAYERS][4]f32 = undefined,
+    nplaques: usize = 0,
+    grounds: [2][3]u8 = .{ .{ 0, 0, 0 }, .{ 0, 0, 0 } },
+    plaques_off: bool = false,
+
+    fn inPlaque(decor: *const CellDecor, x: f32, y: f32) bool {
+        for (decor.plaques[0..decor.nplaques]) |band|
+            if (x >= band[0] and x < band[2] and y >= band[1] and y < band[3]) return true;
+        return false;
+    }
+
+    fn of(chrome: *const pardes.Chrome) CellDecor {
+        var out: CellDecor = .{};
+        if (chrome.decor_dots) |rgb| if (chrome.page) |page| {
+            out.dots = page;
+            out.uniforms[0..4].* = .{ unit(rgb[0]), unit(rgb[1]), unit(rgb[2]), unit(chrome.decor_dot_alpha) };
+            out.uniforms[4..8].* = .{ dp(@floatFromInt(@max(2, chrome.decor_dot_px))), 0.75 * display_scale, 1.25 * display_scale, 0 };
+        };
+        if (chrome.decor_title) |rgb| {
+            out.title = .{ chrome.name_ink, chrome.active_name_ink };
+            out.uniforms[8..12].* = .{ unit(rgb[0]), unit(rgb[1]), unit(rgb[2]), dp(@floatFromInt(@max(1, chrome.decor_title_px))) };
+        }
+        return out;
+    }
+
+    fn unit(v: u8) f32 {
+        return @as(f32, @floatFromInt(v)) / 255;
+    }
+};
+
 /// A logical pixel size in the display's pixels: rounded, at least one.
 fn dp(logical: f32) f32 {
     return @max(1, @round(logical * display_scale));
 }
 
+/// A theme's tag plaques (Chrome.decor_box_*), drawn under the cells of
+/// group `index`: each pane tag, and with the still panes the column and
+/// workspace tags, becomes a framed box inside its own band with a hard
+/// shadow down and right that stays inside the band too, so it never falls
+/// on a body, a grip or the next pane. The focused pane's box is striped,
+/// its words on plates of the tag's ground (their cells stay opaque; the
+/// spaces between let the stripes through, emitInstance); a column or the
+/// workspace takes a quieter box, a one-pixel frame and a two-pixel shadow.
+fn tagPlaques(g: *Gui, gpa: std.mem.Allocator, regions: []const pardes.Region, groups: *const Groups, index: usize, chrome: *const pardes.Chrome, layout: CellLayout, win_w: f32, win_h: f32, track: ?pardes.animation.Track) !void {
+    const border_rgb = chrome.decor_box_border orelse return;
+    if (cell_decor.plaques_off) return;
+    const page = chrome.page orelse bg_default;
+    for (regions) |tag| {
+        const pane = tag.kind == .tag;
+        if (!pane and tag.kind != .column_tag and tag.kind != .workspace_tag) continue;
+        if (tag.rect.w == 0 or tag.rect.h == 0) continue;
+        if (pane and groupOf(groups, tag.serial) != index) continue;
+        if (!pane and index != 0) continue;
+        const plaque = plaqueBox(g, chrome, regions, tag, layout, win_w, win_h) orelse continue;
+        const b = plaque.border;
+        const sh = plaque.shadow;
+        const fill = if (tag.active) chrome.tag_focus_bg else chrome.tag_bg;
+        // The band's own ground, then the shadow, the frame and the fill.
+        try addDecor(g, gpa, plaque.band[0], plaque.band[1], plaque.band[2], plaque.band[3], page, 1, track, win_w, win_h);
+        const shadow_rgb = chrome.decor_box_shadow orelse border_rgb;
+        try addDecor(g, gpa, plaque.box[0] + sh[0], plaque.box[1] + sh[1], plaque.box[2] + sh[0], plaque.box[3] + sh[1], if (pane) shadow_rgb else mixRgb(shadow_rgb, page), 1, track, win_w, win_h);
+        try addDecor(g, gpa, plaque.box[0], plaque.box[1], plaque.box[2], plaque.box[3], border_rgb, 1, track, win_w, win_h);
+        const inner: [4]f32 = .{ plaque.box[0] + b, plaque.box[1] + b, plaque.box[2] - b, plaque.box[3] - b };
+        if (pane and tag.active and chrome.decor_box_stripe != null)
+            try addPattern(g, gpa, inner[0], inner[1], inner[2], inner[3], chrome.decor_box_stripe.?, fill, dp(@floatFromInt(@max(1, chrome.decor_box_stripe_px))), true, track, win_w, win_h)
+        else
+            try addDecor(g, gpa, inner[0], inner[1], inner[2], inner[3], fill, 1, track, win_w, win_h);
+    }
+}
+
+const Plaque = struct { band: [4]f32, box: [4]f32, border: f32, shadow: [2]f32 };
+
+/// A tag's plaque in window pixels: its band (the rows, from after the
+/// grip to the end), the framed box round the tagline's text, and the
+/// frame's and the shadow's widths, the shadow cut to what the band's slack
+/// below the text and its right end leave. Null where there is no room.
+fn plaqueBox(g: *const Gui, chrome: *const pardes.Chrome, regions: []const pardes.Region, tag: pardes.Region, layout: CellLayout, win_w: f32, win_h: f32) ?Plaque {
+    const pane = tag.kind == .tag;
+    const first = tag.rect.y;
+    const last = tag.rect.y + tag.rect.h - 1;
+    // From its start, right of its grip: the gap cell before its text is
+    // the plaque's margin, so its frame is never under the first letter.
+    _ = regions;
+    const x0 = @as(f32, @floatFromInt(tag.rect.x)) * layout.w;
+    const x1_cells = @as(f32, @floatFromInt(tag.rect.x + tag.rect.w)) * layout.w;
+    const x1 = if (win_w - x1_cells < layout.w) @max(x1_cells, win_w) else x1_cells;
+    const row_top = @as(f32, @floatFromInt(first)) * layout.h;
+    const row_bottom = @as(f32, @floatFromInt(last + 1)) * layout.h;
+    const text_top = row_top + @as(f32, @floatFromInt(taglineBandOffset(first, win_h, g.cell_h, g.tagline_height)));
+    const text_bottom = @as(f32, @floatFromInt(last)) * layout.h + @as(f32, @floatFromInt(taglineBandOffset(last, win_h, g.cell_h, g.tagline_height) + g.tagline_height));
+    const border = @min(if (pane) dp(@floatFromInt(@max(1, chrome.decor_box_border_px))) else dp(1), @floor(text_top - row_top));
+    if (border < 1) return null;
+    // The shadow's full offset to the right; down, what the slack under the
+    // text leaves (a pixel or three at a tagline under the body's size).
+    const want: f32 = if (pane) dp(@floatFromInt(chrome.decor_box_shadow_px)) else dp(2);
+    const drop = std.math.clamp(@floor(row_bottom - text_bottom - border), 0, want);
+    if (x1 - x0 < 4 * border + want) return null;
+    return .{
+        .band = .{ x0, row_top, x1, row_bottom },
+        .box = .{ x0, text_top - border, x1 - want, text_bottom + border },
+        .border = border,
+        .shadow = .{ want, drop },
+    };
+}
+
 /// The two short bars on each row of a grip with no mode glyph there,
 /// centered in its anchor. Only the panes of group `index`.
 fn gripDecor(g: *Gui, gpa: std.mem.Allocator, regions: []const pardes.Region, cells: []const pardes.Cell, groups: *const Groups, index: usize, chrome: *const pardes.Chrome, layout: CellLayout, cols: u16, rows: u16, win_w: f32, win_h: f32, track: ?pardes.animation.Track) !void {
@@ -8903,7 +9225,8 @@ fn uploadOverlayGpu(g: *Gui, cmd: *c.SDL_GPUCommandBuffer, vertex_count: u32) bo
 }
 
 fn pushLayerOpacity(cmd: *c.SDL_GPUCommandBuffer, pass: ?*c.SDL_GPURenderPass, opacity: f32) void {
-    const uniforms = [4]f32{ opacity, 0, 0, 0 };
+    var uniforms = [4]f32{ opacity, 0, 0, 0 } ++ @as([12]f32, @splat(0));
+    uniforms[4..].* = cell_decor.uniforms;
     c.SDL_PushGPUFragmentUniformData(cmd, 0, &uniforms, @sizeOf(@TypeOf(uniforms)));
     // The source alpha is geometric/image coverage, not window opacity. Its
     // alpha contribution is multiplied by this constant separately, so a
diff --git a/src/surface.zig b/src/surface.zig
index 523cba43..5b850a8b 100644
--- a/src/surface.zig
+++ b/src/surface.zig
@@ -428,6 +428,26 @@ pub const Chrome = struct {
     /// The scroll column's width, button and scrollbar alike, in pixels at
     /// a 17px tagline (acme's 12 at its font); a pixel shell scales it.
     rail_px: u8 = 12,
+    /// The theme's ornament (colors.Decor), a pixel shell's alone: the dot
+    /// grid on the page, the scroll track's checker, the tags' plaques
+    /// (frame, shadow, the focused one's stripes) and the file name's shadow, each null when the theme has none, sizes
+    /// in logical pixels. `name_ink` and `active_name_ink` are the file
+    /// name's colours in a tag, which the shadow goes under.
+    decor_dots: ?[3]u8 = null,
+    decor_dot_alpha: u8 = 0,
+    decor_dot_px: u8 = 22,
+    decor_checker: ?[3]u8 = null,
+    decor_checker_px: u8 = 3,
+    decor_box_border: ?[3]u8 = null,
+    decor_box_border_px: u8 = 2,
+    decor_box_shadow: ?[3]u8 = null,
+    decor_box_shadow_px: u8 = 5,
+    decor_box_stripe: ?[3]u8 = null,
+    decor_box_stripe_px: u8 = 2,
+    decor_title: ?[3]u8 = null,
+    decor_title_px: u8 = 2,
+    name_ink: [3]u8 = .{ 0, 0, 0 },
+    active_name_ink: [3]u8 = .{ 0, 0, 0 },
 };
 
 /// The canonical interface: what a frame of pardes IS. The tty shell writes
diff --git a/src/themes/lapis.zig b/src/themes/lapis.zig
new file mode 100644
index 00000000..46623fc2
--- /dev/null
+++ b/src/themes/lapis.zig
@@ -0,0 +1,92 @@
+//! Lapis: 0x4200.cafe's illuminated manuscript (web/theme/lapis.css) as a
+//! pardes theme. Ultramarine vellum, gold leaf and vermilion rubrics: the
+//! page is lapis-deep, the tags lapis with their names in gold, the text
+//! vellum. The site's ornament comes with it as the theme's `decor`, drawn
+//! inside the existing chrome (docs/render-pipeline.md §10, decision 1):
+//! a gold dot grid on the page under the pane bodies, a gold and lapis
+//! checker in the scroll column, every tag a gold-framed plaque with the
+//! trail's hard vermilion shadow (inside its own band: in a tiled layout a
+//! shadow past it would fall on the next pane or its grip, and no ornament
+//! may cover a focus indicator), the focused one striped like the code
+//! window's title bar, and the file name's vermilion offset shadow.
+pub const theme = .{
+    .name = "lapis",
+    // --lapis-deep, --vellum
+    .bg = .{ 0x0a, 0x10, 0x30 },
+    .fg = .{ 0xee, 0xe6, 0xd2 },
+    // A gold highlight in lapis ink, as the directory's current entry.
+    .sel_bg = .{ 0xe8, 0xc4, 0x6a },
+    .sel_fg = .{ 0x0f, 0x1a, 0x4a },
+    // --lapis, --vellum-dim
+    .tag_bg = .{ 0x0f, 0x1a, 0x4a },
+    .tag_fg = .{ 0x9a, 0xa6, 0xd9 },
+    .tag_name_fg = .{ 0xe8, 0xc4, 0x6a },
+    .tag_active_name_fg = .{ 0xf2, 0xd2, 0x80 },
+    // The plaques' hover lapis, taken a step further: 1.5:1 off the tag.
+    .tag_active_bg = .{ 0x25, 0x39, 0x7d },
+    .tag_active_fg = .{ 0xee, 0xe6, 0xd2 },
+    .box = .{ 0xe8, 0xc4, 0x6a },
+    .box_dim = .{ 0x3a, 0x4a, 0x8a },
+    .box_border = .{ 0x9a, 0xa6, 0xd9 },
+    .box_dirty = .{ 0xff, 0x6a, 0x4a },
+    .column_box = .{ 0xff, 0x6a, 0x4a },
+    .column_box_dim = .{ 0x8a, 0x3a, 0x3a },
+    // Rubrics: vermilion keywords, gilded strings, the code window's green
+    // for numbers, vellum-dim comments.
+    .kw = .{ 0xff, 0x6a, 0x4a },
+    .str = .{ 0xe8, 0xc4, 0x6a },
+    .num = .{ 0xe7, 0xff, 0xe0 },
+    .comment = .{ 0x9a, 0xa6, 0xd9 },
+    .lineno = .{ 0x5a, 0x6a, 0xa8 },
+    .lineno_active = .{ 0x6a, 0x7a, 0xb8 },
+    // --lapis-ink under a gold thumb (the page's scrollbar-color).
+    .scroll_track = .{ 0x05, 0x0a, 0x24 },
+    .scroll_thumb = .{ 0xe8, 0xc4, 0x6a },
+    // Gold rules, a vermilion hairline between a tag and its text.
+    .border = .{ 0xe8, 0xc4, 0x6a },
+    // An empty column is the page, not a slab of gold leaf.
+    .empty_col = .{ 0x0a, 0x10, 0x30 },
+    .tag_rule = .{ 0xd4, 0x41, 0x2f },
+    .search_bg = .{ 0x6a, 0x2a, 0x1c },
+    .search_fg = .{ 0xff, 0xd0, 0xb0 },
+    .diagnostic_error = .{ 0xff, 0x6a, 0x4a },
+    .diagnostic_warning = .{ 0xe8, 0xc4, 0x6a },
+    .diagnostic_info = .{ 0x9a, 0xc6, 0xff },
+    .diagnostic_hint = .{ 0xa8, 0xe0, 0xc0 },
+    .decor = .{
+        .page_dots = .{ 0xe8, 0xc4, 0x6a },
+        // #e8c46a22 on the site: a dot a pixel and a half across every 22.
+        .page_dot_alpha = 0x22,
+        .page_dot_px = 22,
+        .rail_checker = .{ 0xe8, 0xc4, 0x6a },
+        .rail_checker_px = 3,
+        // The trail: a 2px gold frame and a 5px vermilion shadow; the code
+        // window's title bar: gold and lapis stripes of 2px.
+        .tag_border = .{ 0xe8, 0xc4, 0x6a },
+        .tag_border_px = 2,
+        .tag_shadow = .{ 0xd4, 0x41, 0x2f },
+        .tag_shadow_px = 5,
+        .tag_stripe = .{ 0xe8, 0xc4, 0x6a },
+        .tag_stripe_px = 2,
+        .title_shadow = .{ 0xd4, 0x41, 0x2f },
+        .title_shadow_px = 2,
+    },
+    .palette = .{
+        .{ 0x0a, 0x10, 0x30 },
+        .{ 0xff, 0x6a, 0x4a },
+        .{ 0xa8, 0xe0, 0xc0 },
+        .{ 0xe8, 0xc4, 0x6a },
+        .{ 0x9a, 0xc6, 0xff },
+        .{ 0xd8, 0xa0, 0xe8 },
+        .{ 0x8a, 0xd8, 0xd8 },
+        .{ 0xee, 0xe6, 0xd2 },
+        .{ 0x9a, 0xa6, 0xd9 },
+        .{ 0xff, 0x9a, 0x6a },
+        .{ 0xc8, 0xf0, 0xd8 },
+        .{ 0xff, 0xde, 0x90 },
+        .{ 0xc0, 0xdc, 0xff },
+        .{ 0xe8, 0xc0, 0xf4 },
+        .{ 0xb0, 0xec, 0xec },
+        .{ 0xff, 0xf8, 0xe8 },
+    },
+};
diff --git a/test/snapshots/theme.golden b/test/snapshots/theme.golden
index 4acf715d..a6bd6e60 100644
--- a/test/snapshots/theme.golden
+++ b/test/snapshots/theme.golden
@@ -645,34 +645,34 @@
 |30: 0-1 d,#ffffea, 2-49 #000000,#ffffea, 50-51 d,#ffffea, 52-99 #000000,#ffffea,
 == snap generated grid=100x31 cursor=4,6
 == style generated grid=100x31
-|0: 0-50 #e0e0e0,#1e262e, 51-59 #e0e0e0,#303840, 60-70 #e0e0e0,#1e262e, 71-99 d,#1e262e,
-|1: 0-1 #ffffff,#4f7b96, 2-2 d,#1e262e, 3-34 #e0e0e0,#1e262e, 35-49 d,#1e262e, 50-51 #ffffff,#4f7b96, 52-52 d,#1e262e, 53-84 #e0e0e0,#1e262e, 85-99 d,#1e262e,
-|2: 0-1 #000000,#ffa060, 2-2 d,#1e262e, 3-49 #e0e0e0,#1e262e, 50-51 #ffffff,#303840, 52-52 d,#1e262e, 53-99 #e0e0e0,#1e262e,
-|3: 0-2 d,#1e262e, 3-20 #e0e0e0,#1e262e, 21-52 d,#1e262e, 53-70 #e0e0e0,#1e262e, 71-99 d,#1e262e,
-|4: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|5: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|6: 0-0 d,#303840, 1-49 d,#161e26, 50-50 d,#303840, 51-99 d,#161e26,
-|7: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|8: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|9: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|10: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|11: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|12: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|13: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|14: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|15: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|16: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|17: 0-1 #ffffff,#303840, 2-2 d,#1e262e, 3-49 #e0e0e0,#1e262e, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|18: 0-2 d,#1e262e, 3-20 #e0e0e0,#1e262e, 21-49 d,#1e262e, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|19: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|20: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|21: 0-0 d,#303840, 1-49 d,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|22: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|23: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|24: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|25: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|26: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|27: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|28: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|29: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
-|30: 0-0 d,#303840, 1-1 d,#161e26, 2-49 #e0e0e0,#161e26, 50-50 d,#303840, 51-51 d,#161e26, 52-99 #e0e0e0,#161e26,
+|0: 0-50 #9aa6d9,#0f1a4a, 51-59 #0f1a4a,#e8c46a, 60-70 #9aa6d9,#0f1a4a, 71-99 d,#0f1a4a,
+|1: 0-1 #ffffff,#8a3a3a, 2-2 d,#25397d, 3-34 #eee6d2,#25397d, 35-49 d,#25397d, 50-51 #ffffff,#8a3a3a, 52-52 d,#0f1a4a, 53-84 #9aa6d9,#0f1a4a, 85-99 d,#0f1a4a,
+|2: 0-1 #000000,#e8c46a, 2-2 d,#25397d, 3-29 #eee6d2,#25397d, 30-37 #f2d280,#25397d, 38-49 #eee6d2,#25397d, 50-51 #ffffff,#6a78b1, 52-52 d,#0f1a4a, 53-79 #9aa6d9,#0f1a4a, 80-87 #e8c46a,#0f1a4a, 88-99 #9aa6d9,#0f1a4a,
+|3: 0-2 d,#25397d, 3-20 #eee6d2,#25397d, 21-49 d,#25397d, 50-52 d,#0f1a4a, 53-70 #9aa6d9,#0f1a4a, 71-99 d,#0f1a4a,
+|4: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|5: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|6: 0-0 d,#e8c46a, 1-49 d,#0a1030, 50-50 d,#e8c46a, 51-99 d,#0a1030,
+|7: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|8: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|9: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|10: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|11: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|12: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|13: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|14: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|15: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|16: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|17: 0-1 #ffffff,#6a78b1, 2-2 d,#0f1a4a, 3-29 #9aa6d9,#0f1a4a, 30-37 #e8c46a,#0f1a4a, 38-49 #9aa6d9,#0f1a4a, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|18: 0-2 d,#0f1a4a, 3-20 #9aa6d9,#0f1a4a, 21-49 d,#0f1a4a, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|19: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|20: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|21: 0-0 d,#e8c46a, 1-49 d,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|22: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|23: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|24: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|25: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|26: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|27: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|28: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|29: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
+|30: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-49 #eee6d2,#0a1030, 50-50 d,#e8c46a, 51-51 d,#0a1030, 52-99 #eee6d2,#0a1030,
diff --git a/test/snapshots/themesel.golden b/test/snapshots/themesel.golden
index 455808ab..8d453978 100644
--- a/test/snapshots/themesel.golden
+++ b/test/snapshots/themesel.golden
@@ -529,7 +529,7 @@
 |27:     19 Theme helix
 |28:     20 Theme dark
 |29:     21 Theme acme
-|30:     22 Theme acid
+|30:     22 Theme lapis
 == style step-helix grid=100x31
 |0: 0-70 #949494,#121212, 71-99 d,#121212,
 |1: 0-1 #ffffff,#826f46, 2-2 d,#3a3a3a, 3-34 #bdbdbd,#3a3a3a, 35-99 d,#3a3a3a,
@@ -561,7 +561,7 @@
 |27: 0-0 d,#121212, 1-1 d,#080808, 2-6 #626262,#080808,b 7-17 #bdbdbd,#080808, 18-99 d,#080808,
 |28: 0-0 d,#121212, 1-1 d,#080808, 2-6 #626262,#080808, 7-16 #bdbdbd,#080808, 17-99 d,#080808,
 |29: 0-0 d,#121212, 1-1 d,#080808, 2-6 #626262,#080808, 7-16 #bdbdbd,#080808, 17-99 d,#080808,
-|30: 0-0 d,#121212, 1-1 d,#080808, 2-6 #626262,#080808, 7-16 #bdbdbd,#080808, 17-99 d,#080808,
+|30: 0-0 d,#121212, 1-1 d,#080808, 2-6 #626262,#080808, 7-17 #bdbdbd,#080808, 18-99 d,#080808,
 == snap step-dark grid=100x31 cursor=7,27
 |17:     10 Theme solarium                                                                         Theme
 |18:     11 Theme spectrum
@@ -575,8 +575,8 @@
 |26:     19 Theme helix
 |27:     20 Theme dark
 |28:     21 Theme acme
-|29:     22 Theme acid
-|30:     23 Theme acme_helix
+|29:     22 Theme lapis
+|30:     23 Theme acid
 == style step-dark grid=100x31
 |0: 0-70 #969696,#2c2a3e, 71-99 d,#2c2a3e,
 |1: 0-1 #ffffff,#867a4e, 2-2 d,#484566, 3-34 #c8c8c8,#484566, 35-99 d,#484566,
@@ -621,9 +621,9 @@
 |25:     19 Theme helix
 |26:     20 Theme dark
 |27:     21 Theme acme
-|28:     22 Theme acid
-|29:     23 Theme acme_helix
-|30:     24 Theme adwaita_dark
+|28:     22 Theme lapis
+|29:     23 Theme acid
+|30:     24 Theme acme_helix
 == style step-acme grid=100x31
 |0: 0-70 #000000,#eaffff, 71-99 d,#eaffff,
 |1: 0-1 #000000,#8888cc, 2-2 d,#eaffff, 3-34 #000000,#eaffff, 35-99 d,#eaffff,
@@ -653,9 +653,9 @@
 |25: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-17 #000000,#ffffea, 18-99 d,#ffffea,
 |26: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-16 #000000,#ffffea, 17-99 d,#ffffea,
 |27: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea,b 7-16 #000000,#ffffea, 17-99 d,#ffffea,
-|28: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-16 #000000,#ffffea, 17-99 d,#ffffea,
-|29: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-22 #000000,#ffffea, 23-99 d,#ffffea,
-|30: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-24 #000000,#ffffea, 25-99 d,#ffffea,
+|28: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-17 #000000,#ffffea, 18-99 d,#ffffea,
+|29: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-16 #000000,#ffffea, 17-99 d,#ffffea,
+|30: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-22 #000000,#ffffea, 23-99 d,#ffffea,
 == snap step-generated grid=100x31 cursor=7,27
 |17:     12 Theme harvest                                                                          Theme
 |18:     13 Theme clay
@@ -667,42 +667,42 @@
 |24:     19 Theme helix
 |25:     20 Theme dark
 |26:     21 Theme acme
-|27:     22 Theme acid
-|28:     23 Theme acme_helix
-|29:     24 Theme adwaita_dark
-|30:     25 Theme adwaita_light
+|27:     22 Theme lapis
+|28:     23 Theme acid
+|29:     24 Theme acme_helix
+|30:     25 Theme adwaita_dark
 == style step-generated grid=100x31
-|0: 0-70 #e0e0e0,#1e262e, 71-99 d,#1e262e,
-|1: 0-1 #ffffff,#4f7b96, 2-2 d,#1e262e, 3-34 #e0e0e0,#1e262e, 35-99 d,#1e262e,
-|2: 0-1 #ffffff,#303840, 2-2 d,#1e262e, 3-59 #e0e0e0,#1e262e, 60-99 d,#1e262e,
-|3: 0-0 d,#303840, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|4: 0-0 d,#303840, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|5: 0-0 d,#303840, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|6: 0-0 d,#303840, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|7: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|8: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|9: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|10: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|11: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-12 #e0e0e0,#161e26, 13-99 d,#161e26,
-|12: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-13 #e0e0e0,#161e26, 14-99 d,#161e26,
-|13: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-13 #e0e0e0,#161e26, 14-99 d,#161e26,
-|14: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-13 #e0e0e0,#161e26, 14-99 d,#161e26,
-|15: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-13 #e0e0e0,#161e26, 14-99 d,#161e26,
-|16: 0-1 #000000,#ffa060, 2-2 d,#1e262e, 3-61 #e0e0e0,#1e262e, 62-99 d,#1e262e,
-|17: 0-0 d,#303840, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-19 #e0e0e0,#161e26, 20-92 d,#161e26, 93-93 d,#1e262e, 94-98 #e0e0e0,#1e262e, 99-99 d,#1e262e,
-|18: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-16 #e0e0e0,#161e26, 17-99 d,#161e26,
-|19: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-23 #e0e0e0,#161e26, 24-99 d,#161e26,
-|20: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-22 #e0e0e0,#161e26, 23-99 d,#161e26,
-|21: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-25 #e0e0e0,#161e26, 26-99 d,#161e26,
-|22: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-99 d,#161e26,
-|23: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-34 #e0e0e0,#161e26, 35-99 d,#161e26,
-|24: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-17 #e0e0e0,#161e26, 18-99 d,#161e26,
-|25: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-16 #e0e0e0,#161e26, 17-99 d,#161e26,
-|26: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-16 #e0e0e0,#161e26, 17-99 d,#161e26,
-|27: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26,b 7-16 #e0e0e0,#161e26, 17-99 d,#161e26,
-|28: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-22 #e0e0e0,#161e26, 23-99 d,#161e26,
-|29: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-24 #e0e0e0,#161e26, 25-99 d,#161e26,
-|30: 0-0 d,#1e262e, 1-1 d,#161e26, 2-6 #303840,#161e26, 7-25 #e0e0e0,#161e26, 26-99 d,#161e26,
+|0: 0-70 #9aa6d9,#0f1a4a, 71-99 d,#0f1a4a,
+|1: 0-1 #ffffff,#8a3a3a, 2-2 d,#25397d, 3-34 #eee6d2,#25397d, 35-99 d,#25397d,
+|2: 0-1 #ffffff,#6a78b1, 2-2 d,#0f1a4a, 3-32 #9aa6d9,#0f1a4a, 33-37 #e8c46a,#0f1a4a, 38-59 #9aa6d9,#0f1a4a, 60-99 d,#0f1a4a,
+|3: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|4: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|5: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|6: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|7: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|8: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|9: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|10: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|11: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-12 #eee6d2,#0a1030, 13-99 d,#0a1030,
+|12: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-13 #eee6d2,#0a1030, 14-99 d,#0a1030,
+|13: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-13 #eee6d2,#0a1030, 14-99 d,#0a1030,
+|14: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-13 #eee6d2,#0a1030, 14-99 d,#0a1030,
+|15: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-13 #eee6d2,#0a1030, 14-99 d,#0a1030,
+|16: 0-1 #000000,#e8c46a, 2-2 d,#25397d, 3-32 #eee6d2,#25397d, 33-39 #f2d280,#25397d, 40-61 #eee6d2,#25397d, 62-99 d,#25397d,
+|17: 0-0 d,#e8c46a, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-19 #eee6d2,#0a1030, 20-92 d,#0a1030, 93-93 d,#0f1a4a, 94-98 #9aa6d9,#0f1a4a, 99-99 d,#0f1a4a,
+|18: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-16 #eee6d2,#0a1030, 17-99 d,#0a1030,
+|19: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-23 #eee6d2,#0a1030, 24-99 d,#0a1030,
+|20: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-22 #eee6d2,#0a1030, 23-99 d,#0a1030,
+|21: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-25 #eee6d2,#0a1030, 26-99 d,#0a1030,
+|22: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-99 d,#0a1030,
+|23: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-34 #eee6d2,#0a1030, 35-99 d,#0a1030,
+|24: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-17 #eee6d2,#0a1030, 18-99 d,#0a1030,
+|25: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-16 #eee6d2,#0a1030, 17-99 d,#0a1030,
+|26: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-16 #eee6d2,#0a1030, 17-99 d,#0a1030,
+|27: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #6a7ab8,#0a1030,b 7-17 #eee6d2,#0a1030, 18-99 d,#0a1030,
+|28: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-16 #eee6d2,#0a1030, 17-99 d,#0a1030,
+|29: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-22 #eee6d2,#0a1030, 23-99 d,#0a1030,
+|30: 0-0 d,#050a24, 1-1 d,#0a1030, 2-6 #5a6aa8,#0a1030, 7-24 #eee6d2,#0a1030, 25-99 d,#0a1030,
 == snap step-back grid=100x31 cursor=7,26
 == style step-back grid=100x31
 |0: 0-70 #000000,#eaffff, 71-99 d,#eaffff,
@@ -732,25 +732,25 @@
 |24: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-17 #000000,#ffffea, 18-99 d,#ffffea,
 |25: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-16 #000000,#ffffea, 17-99 d,#ffffea,
 |26: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea,b 7-16 #000000,#ffffea, 17-99 d,#ffffea,
-|27: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-16 #000000,#ffffea, 17-99 d,#ffffea,
-|28: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-22 #000000,#ffffea, 23-99 d,#ffffea,
-|29: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-24 #000000,#ffffea, 25-99 d,#ffffea,
-|30: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-25 #000000,#ffffea, 26-99 d,#ffffea,
+|27: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-17 #000000,#ffffea, 18-99 d,#ffffea,
+|28: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-16 #000000,#ffffea, 17-99 d,#ffffea,
+|29: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-22 #000000,#ffffea, 23-99 d,#ffffea,
+|30: 0-0 d,#99994c, 1-1 d,#ffffea, 2-6 #999980,#ffffea, 7-24 #000000,#ffffea, 25-99 d,#ffffea,
 == snap tail grid=100x31 cursor=7,29
-|17:    234 Theme wolf_alabaster_dark
-|18:    235 Theme wolf_alabaster_dark_bg
-|19:    236 Theme wolf_alabaster_dark_mono
-|20:    237 Theme wolf_alabaster_light
-|21:    238 Theme wolf_alabaster_light_bg
-|22:    239 Theme wolf_alabaster_light_mono
-|23:    240 Theme yellowed
-|24:    241 Theme yo
-|25:    242 Theme yo_berry
-|26:    243 Theme yo_light
-|27:    244 Theme zed_onedark
-|28:    245 Theme zed_onelight
-|29:    246 Theme zenburn
-|30:    247
+|17:    235 Theme wolf_alabaster_dark
+|18:    236 Theme wolf_alabaster_dark_bg
+|19:    237 Theme wolf_alabaster_dark_mono
+|20:    238 Theme wolf_alabaster_light
+|21:    239 Theme wolf_alabaster_light_bg
+|22:    240 Theme wolf_alabaster_light_mono
+|23:    241 Theme yellowed
+|24:    242 Theme yo
+|25:    243 Theme yo_berry
+|26:    244 Theme yo_light
+|27:    245 Theme zed_onedark
+|28:    246 Theme zed_onelight
+|29:    247 Theme zenburn
+|30:    248
 == snap picked grid=100x31 cursor=7,3
 |16:     14 line 14
 |17:     15 line 15
-- 
cgit v1.3


From c1dbb16d069a54f52533f346655b0fc49026c9a4 Mon Sep 17 00:00:00 2001
From: Gabriel Schneider <gbrls@0x4200.cafe>
Date: Tue, 29 Sep 2026 06:58:19 -0300
Subject: G7: a moving pane casts a shadow, a retargeted move keeps its speed,
 a dissolve crossfades

- Track.launch: a move retargeted mid-way (Presentation.sync) starts at
  the old move's speed along the new one's longest side (carriedLaunch,
  Motion.easeFrom/speedFrom), so a second change during a slide bends the
  motion instead of stopping it dead. The macOS track ABI grows the float
  (pardes.h, 48 bytes; its reserved byte is named motion, as in Zig).
- A pane that slides, zooms or rises casts Lift's soft shadow at
  sin(pi x progress) of its strength, on the other panes' bodies and
  rails alone, under the same contrast ceiling, carried by its track.
- The GUI's PanelDissolve is a crossfade: the new cell drawn first, the
  old one over it at 1 - progress, premultiplied, on the blending cell
  pipeline for such groups (new cells now emitted before old ones, as the
  old layers already came after the new). sRGB blend, not linear light
  (documented). The tty keeps its per-cell swap.

Presentation.zig's and animation.zig's tests were not in any test root;
pardes.zig's test block now takes them in.

Tests: a retargeted move carries its speed and still lands exactly; a
moving pane's shadow is clipped off every tag, grip and its own body,
none at the start or the landing, most mid-way. GUI golden 18 changes by
the shadow (frame 6 of a slide). Gates as G6. Feel review:
.scratch/render/transitions/.
---
 docs/effects.md               |  15 ++++++
 shaders/prebuilt/ui.frag.glsl |  17 ++++---
 shaders/prebuilt/ui.frag.spv  | Bin 8448 -> 8176 bytes
 shaders/ui.frag.glsl          |  17 ++++---
 src/Presentation.zig          |  39 +++++++++++++++-
 src/animation.zig             |  33 ++++++++++++--
 src/gui/gui.zig               | 103 ++++++++++++++++++++++++++++++++++++------
 src/macos.zig                 |   2 +-
 src/macos/pardes.h            |   3 +-
 src/pardes.zig                |   2 +
 10 files changed, 199 insertions(+), 32 deletions(-)

(limited to 'shaders/prebuilt/ui.frag.spv')

diff --git a/docs/effects.md b/docs/effects.md
index 04757aca..58c0098e 100644
--- a/docs/effects.md
+++ b/docs/effects.md
@@ -40,6 +40,7 @@ why. The verdict is the user's.
 | G4 bloom, vignette, grain | `Bloom`, `Vignette`, `Grain` `0..3` (off) | bundled post passes; none touches a tag, grip, notice or the cursor (pardesSpare); each capped per theme (pardesCap) | .scratch/render/{bloom,vignette,grain}/ (levels 0-3 on forge, dusk, acme; crops; mp4 stepping through the levels) | pending |
 | G5 lapis | `Theme lapis` (its `decor`) | a native theme with ornament: tag plaques with hard shadows inside their bands (the focused one striped), dots, rail checker, title shadow | .scratch/render/lapis/ (whole window at 1x and 2x, crops, a slide mp4) | pending |
 | G6 smooth scroll | follows `Motion` (on through the default smooth; `Motion off` lands at once) | a mouse wheel's notch glides, a touchpad follows the finger | .scratch/render/scroll/ (glide-<flavour>.mp4, quarter speed, strips) | pending |
+| G7 panel transitions | `PanelSlide`, `PanelZoom`, `PanelVertical`, `PanelDissolve` (off) with `Motion` | a moving pane casts a shadow; a retargeted move keeps its speed; the GUI's dissolve is a crossfade | .scratch/render/transitions/ (slide smooth, bouncy, retargeted; dissolve) | pending |
 
 ## Motion flavours
 
@@ -161,3 +162,17 @@ continuous path (Pardes.shell_continuous), so the shell draws every loop
 while it moves and a virtual clock moves with it; idle, it costs nothing.
 A PDF page scrolls as before. The test feed takes wheel events
 (ESC]777;mouse;wheel;<amount>;<x>;<y>BEL).
+
+Notes on G7: the geometry already followed the Motion flavour's spring
+(sxrrwplk); a move retargeted mid-way now carries its speed on
+(Track.launch, from the old move's speed along the new one's longest
+side), so a second Newcol during a slide bends the motion instead of
+stopping it dead. A pane that slides, zooms or rises stands off the page
+while it moves: a soft shadow as Lift's, at sin(pi x progress) of its
+strength (none as it sets out or lands), on the other panes' bodies and
+rails alone and under the same contrast ceiling, moving with the pane. The
+GUI's PanelDissolve is a crossfade: a changed cell's new form drawn whole,
+its old one over it at 1 - progress; the blend is in sRGB, not linear
+light (a two-colour mix in linear light needs both in one shader; open
+point 3). The tty keeps its per-cell swap. GUI golden 18-mid-transition
+changes (the slide's shadow at frame 6).
diff --git a/shaders/prebuilt/ui.frag.glsl b/shaders/prebuilt/ui.frag.glsl
index 62dbbfa2..cb38fff1 100644
--- a/shaders/prebuilt/ui.frag.glsl
+++ b/shaders/prebuilt/ui.frag.glsl
@@ -82,13 +82,18 @@ void main() {
     }
     vec4 cell = vec4(mix(under.rgb, v_fg, a), mix(under.a, 1.0, a));
 
-    // 3 = data dissolve. Changed cells retain the frozen old cell until their
-    // stable threshold, then atomically become the new cell. Exact endpoints
-    // mirror panel_animation.dissolveRevealed, including the zero hash.
+    // 3 = dissolve, a crossfade (G7): a changed cell's new form is drawn
+    // first, whole, and its frozen old one over it at 1 - progress,
+    // premultiplied (the frame's cells blend over, pipeline_over), so the
+    // old fades out as the new comes in; at the ends, exactly one of them.
+    // The tty keeps its per-cell swap (panel_animation.dissolveRevealed).
     if (effect == 3u) {
-        bool reveal = progress >= 1.0 || (progress > 0.0 && noise < progress);
-        if (oldLayer ? reveal : !reveal) discard;
-        o_col = cell;
+        if (!oldLayer) {
+            o_col = cell;
+            return;
+        }
+        if (progress >= 1.0) discard;
+        o_col = cell * (1.0 - progress);
         return;
     }
 
diff --git a/shaders/prebuilt/ui.frag.spv b/shaders/prebuilt/ui.frag.spv
index d83d9c55..15318214 100644
Binary files a/shaders/prebuilt/ui.frag.spv and b/shaders/prebuilt/ui.frag.spv differ
diff --git a/shaders/ui.frag.glsl b/shaders/ui.frag.glsl
index 62dbbfa2..cb38fff1 100644
--- a/shaders/ui.frag.glsl
+++ b/shaders/ui.frag.glsl
@@ -82,13 +82,18 @@ void main() {
     }
     vec4 cell = vec4(mix(under.rgb, v_fg, a), mix(under.a, 1.0, a));
 
-    // 3 = data dissolve. Changed cells retain the frozen old cell until their
-    // stable threshold, then atomically become the new cell. Exact endpoints
-    // mirror panel_animation.dissolveRevealed, including the zero hash.
+    // 3 = dissolve, a crossfade (G7): a changed cell's new form is drawn
+    // first, whole, and its frozen old one over it at 1 - progress,
+    // premultiplied (the frame's cells blend over, pipeline_over), so the
+    // old fades out as the new comes in; at the ends, exactly one of them.
+    // The tty keeps its per-cell swap (panel_animation.dissolveRevealed).
     if (effect == 3u) {
-        bool reveal = progress >= 1.0 || (progress > 0.0 && noise < progress);
-        if (oldLayer ? reveal : !reveal) discard;
-        o_col = cell;
+        if (!oldLayer) {
+            o_col = cell;
+            return;
+        }
+        if (progress >= 1.0) discard;
+        o_col = cell * (1.0 - progress);
         return;
     }
 
diff --git a/src/Presentation.zig b/src/Presentation.zig
index 15ed9ea6..5cec73e0 100644
--- a/src/Presentation.zig
+++ b/src/Presentation.zig
@@ -183,7 +183,7 @@ pub fn sync(self: *Presentation, p: *Pardes) void {
                 prior.?.from
             else
                 old.box;
-            const next = stamp(p, .{
+            var next = stamp(p, .{
                 .serial = pane.serial,
                 .pane = @intCast(id),
                 .phase = if (!same_lifetime or
@@ -192,6 +192,10 @@ pub fn sync(self: *Presentation, p: *Pardes) void {
                 .from = from,
                 .to = target,
             });
+            // Retargeted mid-way from where it shows: it keeps its speed.
+            if (same_lifetime and shown != null) if (prior) |old_move| {
+                next.launch = carriedLaunch(old_move, next);
+            };
             self.tracks[id] = next;
             changed = true;
             animated_change = true;
@@ -230,6 +234,23 @@ fn stamp(p: *const Pardes, track: Track) Track {
     return stamped;
 }
 
+/// A retargeted move's starting speed, in its own lengths per unit of
+/// progress, from the old move's speed now (cells per frame), along the
+/// new move's longest side; within four lengths per unit either way.
+fn carriedLaunch(old_move: Track, next: Track) f32 {
+    const v = old_move.velocity();
+    if (next.frames() <= 1) return 0;
+    const steps: f32 = @floatFromInt(next.frames() - 1);
+    const d: [4]f32 = .{ next.to.x - next.from.x, next.to.y - next.from.y, next.to.w - next.from.w, next.to.h - next.from.h };
+    const vs: [4]f32 = .{ v.x, v.y, v.w, v.h };
+    var axis: usize = 0;
+    for (d, 0..) |value, i| if (@abs(value) > @abs(d[axis])) {
+        axis = i;
+    };
+    if (@abs(d[axis]) < 1e-3) return 0;
+    return std.math.clamp(vs[axis] * steps / d[axis], -4, 4);
+}
+
 fn appendClosing(self: *Presentation, track: Track) bool {
     std.debug.assert(track.phase == .closing);
     const baseline = self.previous_layout[track.pane] orelse return false;
@@ -784,3 +805,19 @@ test "presentation snapshots own compact body and tag rows across later edits" {
     try std.testing.expectEqual(@as(u8, 'B'), state.previous_body_layers[0].cells[0].text[0]);
     try std.testing.expectEqual(@as(u8, 'U'), state.previous_tag_layers[0].cells[0].text[0]);
 }
+
+test "a move retargeted mid-way carries its speed into the new one" {
+    const smooth = @intFromEnum(animation.Motion.Flavour.smooth) + 1;
+    const first: Track = .{ .serial = 1, .phase = .moving, .effect = .slide, .motion = smooth, .frame = 4, .frame_count = 14, .from = .{ .x = 0, .y = 1, .w = 40, .h = 20 }, .to = .{ .x = 40, .y = 1, .w = 40, .h = 20 } };
+    const was = first.velocity();
+    try std.testing.expect(was.x > 0.5);
+    var next: Track = .{ .serial = 1, .phase = .moving, .effect = .slide, .motion = smooth, .frame_count = 14, .from = first.presented(), .to = .{ .x = 60, .y = 1, .w = 40, .h = 20 } };
+    next.launch = carriedLaunch(first, next);
+    try std.testing.expect(next.launch > 0);
+    // It sets off at the speed the old one had, not from a stop.
+    const now = next.velocity();
+    try std.testing.expectApproxEqRel(was.x, now.x, 0.15);
+    // And still lands exactly.
+    next.frame = 13;
+    try std.testing.expectEqual(next.to.x, next.presented().x);
+}
diff --git a/src/animation.zig b/src/animation.zig
index 12d352d1..855fef03 100644
--- a/src/animation.zig
+++ b/src/animation.zig
@@ -136,6 +136,10 @@ pub const Track = extern struct {
     frame_count: u16 = 0,
     from: Box = .{},
     to: Box = .{},
+    /// The move's speed as it starts, in its lengths per unit of progress:
+    /// 0 sets off as the flavour does; a move retargeted mid-way carries
+    /// the old one's speed on (Presentation.sync), so it never stops dead.
+    launch: f32 = 0,
 
     pub fn active(track: Track) bool {
         return track.effect != .off and track.frame < track.frames();
@@ -151,7 +155,7 @@ pub const Track = extern struct {
         if (track.phase == .closing and track.effect == .vertical)
             return progressEased(.in_cubic, track.frames(), track.frame);
         if (track.flavour()) |motion|
-            return motion.ease(track.progress());
+            return motion.easeFrom(track.progress(), track.launch);
         return progressEased(track.effect.easing(), track.frames(), track.frame);
     }
 
@@ -163,6 +167,16 @@ pub const Track = extern struct {
         return Motion.of(which);
     }
 
+    /// How fast its presented box moves now, in cells per frame of its
+    /// own (x, y, w, h); zero when it follows no flavour or has landed.
+    pub fn velocity(track: Track) Box {
+        const motion = track.flavour() orelse return .{};
+        const u = track.progress();
+        if (u >= 1 or track.frames() <= 1) return .{};
+        const rate = motion.speedFrom(u, track.launch) / @as(f32, @floatFromInt(track.frames() - 1));
+        return .{ .x = (track.to.x - track.from.x) * rate, .y = (track.to.y - track.from.y) * rate, .w = (track.to.w - track.from.w) * rate, .h = (track.to.h - track.from.h) * rate };
+    }
+
     fn progress(track: Track) f32 {
         if (track.frames() <= 1 or track.frame >= track.frames() - 1) return 1;
         return @as(f32, @floatFromInt(track.frame)) / @as(f32, @floatFromInt(track.frames() - 1));
@@ -180,7 +194,7 @@ pub const Track = extern struct {
         // box, so a click lands on the glyph it is drawn as).
         const motion = track.flavour() orelse return box;
         if (motion.stretch == 0) return box;
-        const factor = 1 + motion.stretch * std.math.clamp(motion.speed(track.progress()) / 4, -1, 1);
+        const factor = 1 + motion.stretch * std.math.clamp(motion.speedFrom(track.progress(), track.launch) / 4, -1, 1);
         if (@abs(track.to.x - track.from.x) >= @abs(track.to.y - track.from.y)) {
             const w = box.w * factor;
             box.x -= (w - box.w) / 2;
@@ -685,16 +699,27 @@ pub const Motion = struct {
     /// flavour's spring (wind-up, overshoot and all), landing exactly on 1
     /// at its end. `instant` is there at once.
     pub fn ease(motion: Motion, u: f32) f32 {
+        return motion.easeFrom(u, 0);
+    }
+
+    /// `ease` for a move that starts already moving at `launch` lengths
+    /// per unit of `u` (a retarget): no wind-up then, the speed carried on.
+    pub fn easeFrom(motion: Motion, u: f32, launch: f32) f32 {
         if (motion.instant or u >= 1) return 1;
         if (u <= 0) return 0;
-        const spring: Spring = .{ .omega = motion.norm, .zeta = motion.zeta, .target = 1, .from = 0, .velocity = (motion.launch - 2 * motion.anticipate) * motion.norm, .settled = false };
+        const kick = if (launch != 0) launch else (motion.launch - 2 * motion.anticipate) * motion.norm;
+        const spring: Spring = .{ .omega = motion.norm, .zeta = motion.zeta, .target = 1, .from = 0, .velocity = kick, .settled = false };
         return spring.value(@intFromFloat(u * std.time.ns_per_s));
     }
 
     /// The same move's speed at `u`, in lengths per unit of `u`.
     pub fn speed(motion: Motion, u: f32) f32 {
+        return motion.speedFrom(u, 0);
+    }
+
+    pub fn speedFrom(motion: Motion, u: f32, launch: f32) f32 {
         const h: f32 = 1.0 / 256.0;
-        return (motion.ease(@min(1, u + h)) - motion.ease(@max(0, u - h))) / (@min(1, u + h) - @max(0, u - h));
+        return (motion.easeFrom(@min(1, u + h), launch) - motion.easeFrom(@max(0, u - h), launch)) / (@min(1, u + h) - @max(0, u - h));
     }
 };
 
diff --git a/src/gui/gui.zig b/src/gui/gui.zig
index 449cae15..b5da9ad6 100644
--- a/src/gui/gui.zig
+++ b/src/gui/gui.zig
@@ -5963,7 +5963,9 @@ fn renderFrame(
                 const track = groups.items[group_index].track;
                 const data_effect = if (track) |active| active.effect == .dissolve else false;
                 const data_diff = data_effect and gripCellChanged(surface, covered, previous_covered, col, row);
-                if (data_diff) emitSurfaceCell(
+                // The new cell, then (a dissolve) the old one fading out over
+                // it, as the old layers come after the new ones.
+                emitSurfaceCell(
                     g,
                     chrome,
                     instances,
@@ -5973,16 +5975,16 @@ fn renderFrame(
                     layout,
                     win_w,
                     win_h,
-                    track,
-                    surface.previous_cells[@as(usize, row) * surface.cols ..][0..surface.cols],
-                    previous_covered[@as(usize, row) * surface.cols ..][0..surface.cols],
+                    if (data_effect and !data_diff) null else track,
+                    line,
+                    line_cover,
                     col,
-                    null,
-                    true,
+                    line_cursor,
                     false,
+                    cursors_shown and at == cursor_idx and !cursor_bar and bodyLayerAt(surface, col, row) == null,
                     page,
                 );
-                emitSurfaceCell(
+                if (data_diff) emitSurfaceCell(
                     g,
                     chrome,
                     instances,
@@ -5992,13 +5994,13 @@ fn renderFrame(
                     layout,
                     win_w,
                     win_h,
-                    if (data_effect and !data_diff) null else track,
-                    line,
-                    line_cover,
+                    track,
+                    surface.previous_cells[@as(usize, row) * surface.cols ..][0..surface.cols],
+                    previous_covered[@as(usize, row) * surface.cols ..][0..surface.cols],
                     col,
-                    line_cursor,
+                    null,
+                    true,
                     false,
-                    cursors_shown and at == cursor_idx and !cursor_bar and bodyLayerAt(surface, col, row) == null,
                     page,
                 );
             }
@@ -6104,7 +6106,10 @@ fn renderFrame(
         }
         const has_shifted = index == 0 and shifted != 0;
         if ((group.cell_count != 0 or has_shifted) and g.vbuf != null) {
-            c.SDL_BindGPUGraphicsPipeline(rp, if (cell_decor.nplaques != 0) g.pipeline_over else g.pipeline);
+            // Blended over what is under: a theme's plaques show through
+            // blank tag cells; a dissolve's old cells fade over its new.
+            const dissolving = if (group.track) |active| active.effect == .dissolve else false;
+            c.SDL_BindGPUGraphicsPipeline(rp, if (cell_decor.nplaques != 0 or dissolving) g.pipeline_over else g.pipeline);
             const samp_binding = c.SDL_GPUTextureSamplerBinding{ .texture = g.atlas_tex, .sampler = g.atlas_sampler };
             c.SDL_BindGPUFragmentSamplers(rp, 0, &samp_binding, 1);
             if (group.cell_count != 0) {
@@ -8715,6 +8720,34 @@ fn buildDecor(g: *Gui, gpa: std.mem.Allocator, surface: *const pardes.Surface, g
                 } else null;
                 try addLift(g, gpa, lift_style, ceilings, box, rim_edge, bodies, grip.lift, track, win_w, win_h);
             }
+            // G7: a pane on the move stands off the page, rising as it sets
+            // out and settling as it lands, its shadow on the other panes'
+            // bodies only (never a tag, a grip or its own text), moving
+            // with it.
+            if (track) |active| if (active.phase != .closing and (active.effect == .slide or active.effect == .zoom or active.effect == .vertical)) {
+                const steps: f32 = @floatFromInt(@max(1, active.frames() -| 1));
+                const u = std.math.clamp(@as(f32, @floatFromInt(active.frame)) / steps, 0, 1);
+                const lift = @sin(std.math.pi * u);
+                var box: [4]f32 = .{ std.math.inf(f32), std.math.inf(f32), -std.math.inf(f32), -std.math.inf(f32) };
+                var others: [pardes.MAX_PANES][4]f32 = undefined;
+                var nothers: usize = 0;
+                for (placed) |part| {
+                    if (part.kind != .tag and part.kind != .rail and part.kind != .body and part.kind != .grip) continue;
+                    const r = bodyPixels(part, layout);
+                    if (part.owner == active.pane) {
+                        box = .{ @min(box[0], r[0]), @min(box[1], r[1]), @max(box[2], r[2]), @max(box[3], r[3]) };
+                    } else if ((part.kind == .body or part.kind == .rail) and nothers < others.len) {
+                        others[nothers] = r;
+                        nothers += 1;
+                    }
+                }
+                if (box[2] > box[0] and lift > 0.01) {
+                    const h: f32 = @floatFromInt(g.cell_h);
+                    const first = g.decor.items.len;
+                    try addSoft(g, gpa, box, Shadow.sigma * h * lift, Shadow.side * h * lift, Shadow.drop * h * lift, @min(Shadow.strength * lift, ceilings.shadow), .{ 0, 0, 0 }, track, win_w, win_h);
+                    try clipToBodies(g, gpa, first, others[0..nothers]);
+                }
+            };
         }
         // A notice chip is tagline hung over the body's top rows, so it is
         // ruled off from the text beneath it the way a tag is: the same
@@ -9287,6 +9320,50 @@ test "decor is read from the regions, each pane's in its own group" {
     try std.testing.expectEqual(@as(u32, 0), groups.items[groups.ink].decor_count);
 }
 
+test "a pane on the move casts a shadow on the other panes' bodies alone, most at mid-way" {
+    const gpa = std.testing.allocator;
+    const core = try pardes.Pardes.init(gpa, .{ .cols = 80, .rows = 24 });
+    defer core.deinit();
+    _ = try core.newShell(1, "");
+    try std.testing.expect(pardes.layout.splitColumn(core, 0, 1, false));
+    try std.testing.expect(core.executeBuiltinLine(0, "Theme acme"));
+    for (0..40) |_| core.update(.tick);
+    pardes.test_api.sync(core);
+    const s = try core.render(core.scratch.allocator());
+    var g: Gui = undefined;
+    g.decor = .empty;
+    defer g.decor.deinit(gpa);
+    g.cell_w = 10;
+    g.cell_h = 20;
+    g.tagline_width = 6;
+    g.tagline_height = 12;
+    const layout = fixedCellLayout(&g);
+    const serial = core.panes[1].?.serial;
+    var strengths: [3]f32 = @splat(0);
+    for ([_]u16{ 0, 6, 12 }, 0..) |frame, i| {
+        g.decor.clearRetainingCapacity();
+        const moving: pardes.animation.Track = .{ .pane = 1, .serial = serial, .phase = .moving, .effect = .slide, .frame = frame, .frame_count = 13, .from = .{ .x = 0, .y = 1, .w = 40, .h = 23 }, .to = .{ .x = 40, .y = 1, .w = 40, .h = 23 } };
+        var groups = makeGroups(&.{moving}, true);
+        if (!moving.active()) groups = makeGroups(&.{}, true);
+        try buildDecor(&g, gpa, s, &groups, layout, 800, 480, false);
+        for (g.decor.items) |item| {
+            if (item.effect & soft_shadow_bit == 0) continue;
+            strengths[i] = @max(strengths[i], item.fr);
+            // Clipped to pane 0's body or rail, never pane 1's, never a tag.
+            try std.testing.expect(item.clip_x1 >= item.clip_x0);
+            for (s.regionList()) |region| {
+                if (region.kind != .tag and region.kind != .grip and !(region.owner == 1 and (region.kind == .body or region.kind == .rail))) continue;
+                const r = bodyPixels(region, layout);
+                try std.testing.expect(item.clip_x1 <= r[0] or item.clip_x0 >= r[2] or item.clip_y1 <= r[1] or item.clip_y0 >= r[3]);
+            }
+        }
+    }
+    // Rising as it sets out, gone as it lands.
+    try std.testing.expectEqual(@as(f32, 0), strengths[0]);
+    try std.testing.expect(strengths[1] > 0.05);
+    try std.testing.expectEqual(@as(f32, 0), strengths[2]);
+}
+
 /// What a bundled post pass leaves alone (Post.Frame.spare), in window
 /// pixels: every tag with its grip, the column and workspace tags, and the
 /// notices, the chrome the focus indicators live in. A grip, the gap after
diff --git a/src/macos.zig b/src/macos.zig
index d6daf944..4ff13b23 100644
--- a/src/macos.zig
+++ b/src/macos.zig
@@ -2995,7 +2995,7 @@ test "mac panel mask is a literal normalized grayscale texture" {
 
 test "mac panel ABI has the documented compact byte layout" {
     try std.testing.expectEqual(@as(usize, 16), @sizeOf(PanelBox));
-    try std.testing.expectEqual(@as(usize, 44), @sizeOf(PanelTrack));
+    try std.testing.expectEqual(@as(usize, 48), @sizeOf(PanelTrack));
     try std.testing.expectEqual(@as(usize, 0), @offsetOf(PanelTrack, "serial"));
     try std.testing.expectEqual(@as(usize, 4), @offsetOf(PanelTrack, "pane"));
     try std.testing.expectEqual(@as(usize, 5), @offsetOf(PanelTrack, "phase"));
diff --git a/src/macos/pardes.h b/src/macos/pardes.h
index 29f8a37d..46453429 100644
--- a/src/macos/pardes.h
+++ b/src/macos/pardes.h
@@ -108,11 +108,12 @@ typedef struct {
   uint8_t pane;
   uint8_t phase;
   uint8_t effect;
-  uint8_t reserved0;
+  uint8_t motion;
   uint16_t frame;
   uint16_t frame_count;
   pardes_panel_box_s from;
   pardes_panel_box_s to;
+  float launch;
 } pardes_panel_track_s;
 
 #define PARDES_PANEL_OPENING 0u
diff --git a/src/pardes.zig b/src/pardes.zig
index bbd8e7cd..1f2c3175 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -471,6 +471,8 @@ test {
     _ = @import("body_layer.zig");
     _ = @import("draw.zig");
     _ = @import("tag_layer.zig");
+    _ = @import("Presentation.zig");
+    _ = @import("animation.zig");
 }
 
 pub const Builtin = builtins.registry.Builtin();
-- 
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