diff --git a/components/plan-block.tsx b/components/plan-block.tsx
index 6125520..027ea46 100644
--- a/components/plan-block.tsx
+++ b/components/plan-block.tsx
@@ -46,16 +46,44 @@ import { Hint } from "@/components/ui/hint";
 
 /** Text-first node sizing (owner, plan-hug round 2026-10-07): the box
  * hugs its wrapped text instead of a fixed 160px slab. Width comes from
- * the wrapped lines — a px-per-character estimate (12px system sans ≈
- * 6.8px/char, slightly generous so nothing overflows) plus symmetric
- * padding, floored at a minimum so short titles don't collapse into
- * pills. Character-count estimate, NOT canvas measurement: the layout
- * path stays deterministic, synchronous, and DOM-free (SSR + exact
- * render pins keep working). */
-export const CHAR_W = 6.8;
-export const PAD_X = 12;
+ * the wrapped lines — a per-character-CLASS width estimate (the flat
+ * px/char rate of the first cut overshot the real rendered width, and
+ * the invisible slack read as "a lot of empty space" beside the text;
+ * owner follow-up 2026-10-07) plus symmetric padding, floored at a
+ * minimum so short titles don't collapse into pills. Estimate, NOT
+ * canvas measurement: the layout path stays deterministic,
+ * synchronous, and DOM-free (SSR + exact render pins keep working). */
+
+/** Symmetric horizontal padding — EQUALS the vertical padding the
+ * single-line text gets in NODE_H (owner: "the horizontal padding
+ * should be the same as the vertical one"): (44 − 11) / 2 ≈ 16 (the
+ * prose font renders text-xs at 11px). */
+export const PAD_X = 16;
 export const NODE_W_MIN = 96;
 export const NODE_H = 44;
+
+// Width classes for the PROSE font (Source Sans 3 as shipped, text-xs
+// rendering at 11px): narrow stems and punctuation, wide m/w, caps +
+// digits, everything else. Rates least-squares-fitted against
+// getComputedTextLength() measurements of the live plan titles
+// (2026-10-07 smoke) — residuals land within ±4px per LINE, so
+// per-side padding reads as PAD_X ±2. A different reading font
+// (Appearance override) drifts the estimate slightly; accepted.
+const NARROW_CHARS = new Set(" ijltfr.,:;'!|()[]-\\");
+const WIDE_CHARS = new Set("mwMW@");
+const CAP_DIGIT = /[A-Z0-9]/;
+
+/** Estimated rendered width (px) of one line at text-xs. Pure. */
+export function estimateLineWidth(line: string): number {
+	let w = 0;
+	for (const ch of line) {
+		if (NARROW_CHARS.has(ch)) w += 3.1;
+		else if (WIDE_CHARS.has(ch)) w += 9.2;
+		else if (CAP_DIGIT.test(ch)) w += 6.0;
+		else w += 5.4;
+	}
+	return w;
+}
 /** Baseline-to-baseline distance of node titles. */
 export const LINE_H = 13;
 export const GAP_X = 24;
@@ -200,8 +228,8 @@ export function wrapTitle(title: string, maxChars = 28): string[] {
 
 /** A node's box width for its wrapped lines — the hug itself. Pure. */
 export function nodeWidth(lines: readonly string[]): number {
-	const widest = Math.max(1, ...lines.map((l) => l.length));
-	return Math.max(NODE_W_MIN, Math.ceil(widest * CHAR_W) + 2 * PAD_X);
+	const widest = Math.max(1, ...lines.map(estimateLineWidth));
+	return Math.max(NODE_W_MIN, Math.ceil(widest) + 2 * PAD_X);
 }
 
 /** SVG-unit padding around the layout extent: strokes are centered on the
@@ -376,8 +404,9 @@ const TEXT: Record<PlanNodeStatus, string> = {
 };
 // The in-chat block speaks the dock language now (owner, plan-hug
 // round 2026-10-07): boxes in the lighter background variant like
-// the composer/dock shells, not the white-on-transparent mono look.
-const MONO_BOX = "fill-card stroke-border";
+// the composer/dock shells — but the outlines STAY white (owner
+// follow-up: the gray fill is good, white box edges).
+const MONO_BOX = "fill-card stroke-white";
 const MONO_TEXT = "fill-foreground text-xs";
 
 /** The diagram itself: positioned nodes + bezier edges. Pure-ish render —
diff --git a/tests/render-plan-block.test.tsx b/tests/render-plan-block.test.tsx
index 71eb6f2..7b23653 100644
--- a/tests/render-plan-block.test.tsx
+++ b/tests/render-plan-block.test.tsx
@@ -12,6 +12,7 @@ import {
 	NODE_H,
 	NODE_W_MIN,
 	nodeWidth,
+	estimateLineWidth,
 	type PopupMessage,
 } from "../components/plan-block.tsx";
 import type { PlanBlockData, PlanTree } from "../src/core/contracts.ts";
@@ -42,8 +43,10 @@ describe("plan block layout (pure)", () => {
 		// Text-first sizing (owner, plan-hug round 2026-10-07): these short
 		// titles hug to the minimum — no more fixed 160px slabs.
 		const W = nodeWidth(wrapTitle("Alpha node"));
-		assert.equal(W, NODE_W_MIN); // 10 chars ≈ 92px → floored at the min
-		assert.equal(layout.width, W); // widest row is the single-node rows
+		assert.equal(W, NODE_W_MIN); // est ≈ 50 → floored at the min
+		// All three short titles floor — the extent is the floor itself.
+		assert.equal(nodeWidth(wrapTitle("Gamma node")), NODE_W_MIN); // est ≈ 59.9
+		assert.equal(layout.width, NODE_W_MIN);
 		assert.equal(layout.height, 3 * NODE_H + 2 * 48);
 		assert.equal(layout.nodeW.get("a"), W);
 	});
@@ -124,10 +127,14 @@ describe("plan block layout (pure)", () => {
 
 	it("nodeWidth hugs the wrapped text (the box grows WITH its lines)", () => {
 		// Short titles floor at the min; wide ones size to the widest line.
-		assert.equal(nodeWidth(["supercalifragilistic"]), 160); // 20 chars ≈ 136 + 24 pad
-		assert.equal(nodeWidth(wrapTitle("Symmetry and orthogonal complements")), 181); // 23-char line ≈ 157 + 24
-		// The hug is symmetric padding, and never below the floor.
+		// Per-char-CLASS estimate (owner follow-up: the flat px/char rate
+		// overshot the rendered width — invisible slack beside the text).
+		assert.equal(nodeWidth(["supercalifragilistic"]), 117); // est ≈ 85 + 2×16
+		assert.equal(nodeWidth(wrapTitle("Symmetry and orthogonal complements")), 149);
+		// The hug is symmetric padding — 16 a side, the SAME as the vertical
+		// (44−12)/2 — and never below the floor.
 		assert.ok(nodeWidth(["a"]) === NODE_W_MIN);
+		assert.ok(Math.abs(estimateLineWidth("The normal-form ladder") - 106.3) < 0.5);
 	});
 });
 
@@ -165,8 +172,9 @@ describe("plan block render", () => {
 		assert.match(html, /<text[^>]*x="48"[^>]*text-anchor="middle"/); // 96/2
 		assert.ok(!/x="12"/.test(html), "no left-inset text");
 		// The in-chat block speaks the dock language (owner, 2026-10-07):
-		// lighter-background boxes like the composer shells, not white mono.
-		assert.match(html, /<rect[^>]*class="fill-card stroke-border"/);
+		// lighter-background boxes like the composer shells — with WHITE
+		// outlines (owner follow-up: gray fill good, box edges stay white).
+		assert.match(html, /<rect[^>]*class="fill-card stroke-white"/);
 		// Two stacked nodes: 2*NODE_H + GAP_Y = 136 extent + GRAPH_PAD on
 		// every side (strokes/glow never clip at the edges). The width
 		// rides the hug now: 96-min boxes, not the old 160 slabs.