diff --git a/components/answered-card.tsx b/components/answered-card.tsx
index 67c5f6c..303cd80 100644
--- a/components/answered-card.tsx
+++ b/components/answered-card.tsx
@@ -143,11 +143,16 @@ export function AnsweredCard({ answer }: { answer: QuestionAnswerData }) {
 
 			{(answer.thinking ?? answer.note) && (
 				/* The SAME unified row (owner round, 2026-10-05): the quiz answer's
-				    thinking is the identical collapsible ThinkingBlock — and since
-				    owner round three (2026-10-07) IDENTICALLY styled, band and all:
-				    collapsed thinking matches in height everywhere, card or chat
-				    (card-on-card is quiet by design; too light → revert). */
-				<ThinkingBlock testId="your-thinking" label="YOUR THINKING" text={answer.thinking ?? answer.note ?? ""} />
+				    thinking is the identical collapsible ThinkingBlock — one
+				    geometry, and since owner round four (2026-10-07) the band steps
+				    to accent on the card's surface (the same one-step lift the chat
+				    band gets). Collapsed thinking matches in height everywhere. */
+				<ThinkingBlock
+					testId="your-thinking"
+					label="YOUR THINKING"
+					text={answer.thinking ?? answer.note ?? ""}
+					inCard
+				/>
 			)}
 
 			{/* px-3→removed: card p-4 + box px-3 double-inset sat the "Why" label deeper
diff --git a/components/chat.tsx b/components/chat.tsx
index e2e23d1..8c472ea 100644
--- a/components/chat.tsx
+++ b/components/chat.tsx
@@ -1406,7 +1406,7 @@ export function Chat({
 										    inset (the band is the authorship mark against the agent's
 										    transparent prose). The "You" label stays — one register
 										    with the thinking labels. */
-										className="my-2 w-full border-l-[calc(3ch-5px)] border-muted-foreground/30 bg-card py-[5px] pl-[5px] pr-2 font-ui text-xs"
+										className="my-2 w-full border-l-[calc(3ch-8px)] border-muted-foreground/30 bg-card py-1 pl-[8px] pr-4 font-ui text-xs"
 									>
 												{/* The rail GROUPS (owner round 4, 2026-10-05): the YOU heading
 												    sits INSIDE the rail, same mono-xs register and same 1ch
diff --git a/components/thinking-block.tsx b/components/thinking-block.tsx
index 67d0c67..b0ca95b 100644
--- a/components/thinking-block.tsx
+++ b/components/thinking-block.tsx
@@ -23,13 +23,15 @@ import { cn } from "@/lib/utils";
  *  along the left edge. ONE geometry everywhere, in cards and out: the
  *  band padding is a tight 5px (round three: halved — subtle, not tall),
  *  and the left gap MATCHES it, so the rail fills the rest of the 3ch
- *  inset — border-l-[calc(3ch-5px)] pl-[5px]. Total inset stays 3ch (the
- *  chevron-alignment law with the agent's flush rows survives); the rail
- *  grows as the padding shrinks. In-card rows carry the identical
- *  styling (owner round three: same band, same heights — card-on-card is
- *  quiet by design; if it reads too light we revert). `defaultOpen`
- *  marks transcript rows, which arrive EXPANDED (clearly conveyed that
- *  the thinking was sent).
+ *  inset — total inset stays 3ch (the chevron-alignment law with the
+ *  agent's flush rows survives). Round four tunes the split: rail
+ *  thinner (gap 8px, rail calc(3ch-8px)), band padding down to 4px, and
+ *  pr-4 so the expanded text wraps EARLY — the band has a clear right
+ *  edge and text hugging it looks odd. In-card rows (on the card's own
+ *  background) take bg-accent — the same ONE-STEP lift the chat band
+ *  gets (background→card); card→accent (`inCard`). `defaultOpen` marks
+ *  transcript rows, which arrive EXPANDED (clearly conveyed that the
+ *  thinking was sent).
  *
  *  ⌘T (toggle-user-thinking) sets EVERY row to one state via the module
  *  store below — one source of truth, no provider tree: rows subscribe on
@@ -69,6 +71,7 @@ export function ThinkingBlock({
 	testId,
 	dataCommit,
 	defaultOpen = false,
+	inCard = false,
 }: {
 	label?: string;
 	text: string;
@@ -77,6 +80,8 @@ export function ThinkingBlock({
 	dataCommit?: boolean;
 	/** Transcript rows arrive expanded (owner, 2026-10-07). */
 	defaultOpen?: boolean;
+	/** On the card's own background: the band steps to accent (one lift). */
+	inCard?: boolean;
 }) {
 	const [open, setOpen] = useState(() => resolveUserThinkingOpen(defaultOpen));
 	// ⌘T: an explicit global set overrides every row (once set, rows re-sync).
@@ -100,12 +105,13 @@ export function ThinkingBlock({
 			data-testid={testId}
 			data-commit={dataCommit === undefined ? undefined : dataCommit ? "true" : "false"}
 			className={cn(
-				// The rail geometry (owner round three, 2026-10-07): total inset
-				// STAYS 3ch (the chevron-alignment law with the agent's flush
-				// rows). The band padding is a tight 5px (halved from 10px) and
-				// the left gap MATCHES it — the rail fills the rest:
-				// calc(3ch-5px) wide. One geometry everywhere, cards included.
-				"lh-card-enter my-2 w-full border-l-[calc(3ch-5px)] border-muted-foreground/30 bg-card py-[5px] pl-[5px] font-ui text-xs",
+				// Round four (owner, 2026-10-07): total inset still 3ch (the
+				// chevron law); rail thinner (8px gap), padding 4px, and pr-4 —
+				// the text wraps EARLY, never hugging the band's right edge.
+				// In-card rows step the band to accent: the same one-step lift
+				// the chat band gets (background→card → card→accent).
+				"lh-card-enter my-2 w-full border-l-[calc(3ch-8px)] border-muted-foreground/30 py-1 pl-[8px] pr-4 font-ui text-xs",
+				inCard ? "bg-accent" : "bg-card",
 			)}
 		>
 			<button
@@ -113,7 +119,7 @@ export function ThinkingBlock({
 				data-testid={testId ? `${testId}-trigger` : undefined}
 				onClick={() => setOpen((v) => !v)}
 				aria-expanded={open}
-				className="flex w-full items-center gap-2 pr-2 font-medium uppercase tracking-wide text-muted-foreground transition-colors hover:text-foreground"
+				className="flex w-full items-center gap-2 font-medium uppercase tracking-wide text-muted-foreground transition-colors hover:text-foreground"
 			>
 				{label}
 				<ChevronDownIcon className={cn("size-4 shrink-0 transition-transform", open ? "rotate-180" : "rotate-0")} />
diff --git a/tests/render-cards.test.tsx b/tests/render-cards.test.tsx
index 0ede969..dc2df45 100644
--- a/tests/render-cards.test.tsx
+++ b/tests/render-cards.test.tsx
@@ -295,14 +295,14 @@ describe("render smoke tests", () => {
 		// trigger row only — the thinking text is one click away, never loud.
 		assert.ok(html.includes('data-testid="your-thinking-trigger"'), "the trigger row");
 		assert.ok(html.includes('aria-expanded="false"'), "arrives collapsed");
-		// IDENTICAL GEOMETRY (owner round three, 2026-10-07): the in-card row
-		// carries the band too — collapsed thinking matches in height
-		// everywhere, card or chat.
+		// ONE GEOMETRY + THE ACCENT STEP (owner round four, 2026-10-07): the
+		// in-card row carries the accent band — the same one-step lift the
+		// chat band gets; collapsed heights match everywhere.
 		const yourRow = html.slice(html.indexOf('data-testid="your-thinking"'));
-		assert.ok(yourRow.slice(0, 400).includes("bg-card"), "the band inside the card as well");
+		assert.ok(yourRow.slice(0, 400).includes("bg-accent"), "accent inside the card");
 		// THE RAIL GROUPS (owner correction): the label sits INSIDE the rail —
 		// ownership readable from the rail alone, collapsed or expanded.
-		const railAt = html.indexOf("border-l-[calc(3ch-5px)]");
+		const railAt = html.indexOf("border-l-[calc(3ch-8px)]");
 		const trigAt = html.indexOf("your-thinking-trigger");
 		assert.ok(railAt !== -1 && railAt < trigAt, "the rail opens before the label (same quote)");
 		assert.ok(!html.includes("brightness isn&#x27;t distance"), "the text is hidden until expanded");
diff --git a/tests/render-md-blocks.test.tsx b/tests/render-md-blocks.test.tsx
index 781f937..f6e7807 100644
--- a/tests/render-md-blocks.test.tsx
+++ b/tests/render-md-blocks.test.tsx
@@ -243,16 +243,23 @@ describe("md-blocks — the restored plain blockquote (owner round, 2026-10-07)"
 });
 
 describe("ThinkingBlock — the document band + ⌘T sync (owner rounds, 2026-10-07)", () => {
-	it("the row is the document band — one geometry, cards included (owner round three)", () => {
+	it("the row is the document band — round four geometry (owner, 2026-10-07)", () => {
 		const html = renderToStaticMarkup(<ThinkingBlock text="banded" defaultOpen />);
 		assert.ok(html.includes("bg-card"), "the card-color band");
-		assert.ok(html.includes("border-l-[calc(3ch-5px)]"), "the rail fills the 3ch inset");
-		assert.ok(html.includes("py-[5px]") && html.includes("pl-[5px]"), "tight 5px padding, gap matches it");
+		assert.ok(html.includes("border-l-[calc(3ch-8px)]"), "thinner rail — 8px gap inside the 3ch inset");
+		assert.ok(html.includes("py-1") && html.includes("pl-[8px]"), "4px band padding");
+		assert.ok(html.includes("pr-4"), "the text wraps early — air at the band's right edge");
 		assert.ok(html.includes("w-full"), "full width — no chat side");
 		assert.match(html, /aria-expanded="true"/);
 		assert.ok(html.includes("banded"), "text visible on arrival");
 	});
 
+	it("in-card rows step the band to accent — the same one-step lift (owner round four)", () => {
+		const html = renderToStaticMarkup(<ThinkingBlock text="in card" inCard />);
+		assert.ok(html.includes("bg-accent"), "accent on the card's surface");
+		assert.ok(!html.includes("bg-card"), "card-color would vanish on the card");
+	});
+
 	it("⌘T sets every row — explicit sets stomp individual state, late mounts honor the last set", () => {
 		setAllUserThinkingOpen(false);
 		const collapsed = renderToStaticMarkup(<ThinkingBlock text="synced" defaultOpen />);
diff --git a/tests/render-practice-surface.test.tsx b/tests/render-practice-surface.test.tsx
index 721c783..0f4f2b0 100644
--- a/tests/render-practice-surface.test.tsx
+++ b/tests/render-practice-surface.test.tsx
@@ -185,7 +185,7 @@ describe("the practice transcript cards", () => {
 		assert.match(trace, /aria-expanded="true"/);
 		assert.ok(trace.includes("stuck at step two"), "the text is visible on arrival");
 		assert.ok(trace.includes("bg-card"), "the card-color band");
-		assert.ok(trace.includes("border-l-[calc(3ch-5px)]"), "the rail fills the 3ch inset");
+		assert.ok(trace.includes("border-l-[calc(3ch-8px)]"), "thinner rail inside the 3ch inset");
 		const legacy = renderToStaticMarkup(<ThinkingCard data={{ problemCallId: "c", commit: true, text: "It is 42." }} />);
 		assert.match(legacy, /YOUR THINKING/);
 		assert.doesNotMatch(legacy, /Your solution/);