diff --git a/apps/review-desktop/code-oss/src/vs/review/browser/workbench.ts b/apps/review-desktop/code-oss/src/vs/review/browser/workbench.ts
index f16813b83..4c2bfe8af 100644
--- a/apps/review-desktop/code-oss/src/vs/review/browser/workbench.ts
+++ b/apps/review-desktop/code-oss/src/vs/review/browser/workbench.ts
@@ -317,6 +317,8 @@ export class ReviewWorkbench extends Disposable implements IAgentWorkbenchLayout
 	protected _editorPartAutoVisibilitySuppressionCount = 0;
 	protected _hasAppliedInitialEditorSplit = false;
 	private readonly reviewChromeTabStrips: HTMLElement[] = [];
+	private reviewChromeRightPart: HTMLElement | undefined;
+	private reviewChromeRightWidth: string | undefined;
 	private readonly reviewChromeDragListeners = this._register(new DisposableStore());
 	private readonly reviewChromeInsetScheduler = this._register(new RunOnceScheduler(() => this.updateReviewChromeInset(), 0));
 
@@ -996,6 +998,9 @@ export class ReviewWorkbench extends Disposable implements IAgentWorkbenchLayout
 		if (titlebarPart instanceof MainReviewTitlebarPart) {
 			this._register(titlebarPart.onDidChangeChromeInsets(() => this.reviewChromeInsetScheduler.schedule()));
 		}
+		// The Ask column opening or closing moves the window's top-right corner
+		// to another part.
+		this._register(this.onDidChangePartVisibility(() => this.reviewChromeInsetScheduler.schedule()));
 		this._register(editorMainPart.onDidAddGroup(() => this.reviewChromeInsetScheduler.schedule()));
 		this._register(editorMainPart.onDidRemoveGroup(() => this.reviewChromeInsetScheduler.schedule()));
 		this._register(editorMainPart.onDidMoveGroup(() => this.reviewChromeInsetScheduler.schedule()));
@@ -1207,7 +1212,42 @@ export class ReviewWorkbench extends Disposable implements IAgentWorkbenchLayout
 		tabStrip.style.setProperty('--review-explorer-width', `${explorerWidth}px`);
 	}
 
+	/**
+	 * With tabs hidden, whichever part reaches the window's top-right corner,
+	 * a top-row editor group or the Ask column, runs under the window
+	 * controls Windows and Linux draw there. Its canvas reads their width so
+	 * a header's close button clears them. Written on that part, and only
+	 * when it changes, for the reason above.
+	 */
+	private updateReviewChromeRightInset(): void {
+		const bounds = this.mainContainer.getBoundingClientRect();
+		const candidates = [
+			...Array.from(this._editorPartContainer?.getElementsByClassName('editor-group-container') ?? []),
+			...Array.from(this.mainContainer.getElementsByClassName('review-ask-part')),
+		];
+		const part = candidates.find((candidate): candidate is HTMLElement => {
+			if (!isHTMLElement(candidate)) {
+				return false;
+			}
+			const rect = candidate.getBoundingClientRect();
+			return rect.width > 0 && Math.abs(rect.top - bounds.top) <= 1 && Math.abs(rect.right - bounds.right) <= 1;
+		});
+		const titlebarPart = this.getPart(Parts.TITLEBAR_PART);
+		const width = part && titlebarPart instanceof MainReviewTitlebarPart ? `${titlebarPart.chromeInsets.right}px` : undefined;
+		if (part === this.reviewChromeRightPart && width === this.reviewChromeRightWidth) {
+			return;
+		}
+		this.reviewChromeRightPart?.style.removeProperty('--review-chrome-right-width');
+		this.reviewChromeRightPart = part;
+		this.reviewChromeRightWidth = width;
+		if (part && width) {
+			part.style.setProperty('--review-chrome-right-width', width);
+		}
+	}
+
 	private updateReviewChromeInset(): void {
+		this.updateReviewChromeRightInset();
+
 		this.reviewChromeDragListeners.clear();
 		this.mainContainer.classList.remove('review-tab-dragging');
 		for (const tabStrip of this.reviewChromeTabStrips) {
diff --git a/packages/review/app/src/blocks.browser.test.tsx b/packages/review/app/src/blocks.browser.test.tsx
index a3770f30b..9c37c3924 100644
--- a/packages/review/app/src/blocks.browser.test.tsx
+++ b/packages/review/app/src/blocks.browser.test.tsx
@@ -2159,6 +2159,121 @@ it("opens a flow node in a full-screen tour with all its code attachments", asyn
   expect(container.querySelector(".lens-flow-node")).not.toBeNull();
 });
 
+it("keeps a tour's close button in Desktop's right column clear of window controls", async () => {
+  // A step picked on the diagram opens the tour in Desktop's right column,
+  // which runs under the window controls Windows and Linux draw at the
+  // window's top-right corner. The host publishes their width on the column
+  // as --review-chrome-right-width.
+  const controls = document.createElement("div");
+  const column = document.createElement("div");
+
+  controls.style.cssText =
+    "position:fixed;top:0;right:0;width:138px;height:40px;z-index:2147483647";
+  column.style.cssText =
+    "position:fixed;top:0;right:0;bottom:0;width:480px;display:flex;flex-direction:column;--review-chrome-right-width:138px";
+  document.body.append(column, controls);
+
+  try {
+    const { container } = await mountFixture(
+      "sequence",
+      {
+        diagramFullscreenOnClick: false,
+        host: { askPanelHost: () => column },
+      },
+      "position:fixed;top:0;bottom:0;left:0;right:480px",
+    );
+
+    const step = await settled(() =>
+      container.querySelector<HTMLButtonElement>(
+        "button[data-review-anchor-id='step-1']",
+      ),
+    );
+
+    await act(async () => step!.click());
+
+    const close = await settled(() =>
+      document.querySelector<HTMLButtonElement>(
+        'button[aria-label="Close guided tour"]',
+      ),
+    );
+
+    expect(column.contains(close)).toBe(true);
+    // The reader clicks once the panel has slid in.
+    await Promise.allSettled(
+      column
+        .getAnimations({ subtree: true })
+        .map((animation) => animation.finished),
+    );
+    const box = close!.getBoundingClientRect();
+
+    const hit = document.elementFromPoint(
+      box.left + box.width / 2,
+      box.top + box.height / 2,
+    );
+
+    expect(close!.contains(hit)).toBe(true);
+    await act(async () => close!.click());
+    expect(
+      document.querySelector('button[aria-label="Close guided tour"]'),
+    ).toBeNull();
+  } finally {
+    controls.remove();
+    column.remove();
+  }
+});
+
+it("keeps a full-screen tour's close button clear of window controls on the right", async () => {
+  // Windows and Linux draw the window controls over the canvas's top-right
+  // corner, above everything the canvas renders. The host publishes their
+  // width as --review-chrome-right-width.
+  const controls = document.createElement("div");
+
+  controls.style.cssText =
+    "position:fixed;top:0;right:0;width:138px;height:35px;z-index:2147483647";
+  document.body.append(controls);
+
+  try {
+    const { container } = await mountFixture(
+      "sequence",
+      {},
+      "position:fixed;inset:0;--review-chrome-right-width:138px",
+    );
+
+    const expand = await settled(() =>
+      container.querySelector<HTMLButtonElement>(".diagram-tour-button"),
+    );
+
+    await act(async () => expand!.click());
+
+    const close = await settled(() =>
+      container.querySelector<HTMLButtonElement>(
+        '[role="dialog"] button[aria-label="Close guided tour"]',
+      ),
+    );
+
+    expect(close).toBeTruthy();
+    // The reader clicks once the panel has slid in.
+    await Promise.allSettled(
+      close!
+        .closest('[role="dialog"]')!
+        .getAnimations({ subtree: true })
+        .map((animation) => animation.finished),
+    );
+    const box = close!.getBoundingClientRect();
+
+    const hit = document.elementFromPoint(
+      box.left + box.width / 2,
+      box.top + box.height / 2,
+    );
+
+    expect(close!.contains(hit)).toBe(true);
+    await act(async () => close!.click());
+    expect(container.querySelector('[role="dialog"]')).toBeNull();
+  } finally {
+    controls.remove();
+  }
+});
+
 it.each([
   {
     kind: "database_lens" as const,
diff --git a/packages/review/app/src/diagram-tour.tsx b/packages/review/app/src/diagram-tour.tsx
index adfca6b8d..9e17ef795 100644
--- a/packages/review/app/src/diagram-tour.tsx
+++ b/packages/review/app/src/diagram-tour.tsx
@@ -100,7 +100,12 @@ export function DiagramTourOverlay({
         )}
         {...paneResize.separatorProps}
       />
-      <div {...stylex.props(styles.panel, !flow && styles.panelAlone)}>
+      <div
+        {...stylex.props(
+          styles.panel,
+          flow ? styles.panelUnderStage : styles.panelAlone,
+        )}
+      >
         <GuidedTourPanel
           tour={tour}
           activeAnchor={activeAnchor}
@@ -187,12 +192,23 @@ const styles = stylex.create({
     display: { default: null, [narrow]: "none" },
   },
   // Positioned so the panel's floating pager centers on this column.
+  // The panel is the right column, under the window controls that Windows
+  // and Linux draw at the window's right end; its header clears them.
   panel: {
     position: "relative",
     display: "flex",
     flexDirection: "column",
     minWidth: 0,
     minHeight: 0,
+    "--review-header-inset-right": "var(--review-chrome-right-width, 0px)",
+  },
+  // A narrow flow stacks its stage above the panel, so the panel's header
+  // no longer meets the window controls.
+  panelUnderStage: {
+    "--review-header-inset-right": {
+      default: null,
+      [narrow]: "0px",
+    },
   },
   // Without its stage, the panel is the left column, under the window
   // controls.
diff --git a/packages/review/app/src/side-panel-styles.ts b/packages/review/app/src/side-panel-styles.ts
index 99eddd5dc..896cc681a 100644
--- a/packages/review/app/src/side-panel-styles.ts
+++ b/packages/review/app/src/side-panel-styles.ts
@@ -102,7 +102,7 @@ export const panelStyles = stylex.create({
     gap: space.s12,
     minHeight: tokens.reviewHeaderHeight,
     paddingBlock: 0,
-    paddingRight: space.s10,
+    paddingRight: "calc(10px + var(--review-header-inset-right, 0px))",
     paddingLeft: "calc(16px + var(--review-fullscreen-inset, 0px))",
     borderBottomWidth: "1px",
     borderBottomStyle: "solid",
@@ -137,11 +137,13 @@ export const panelStyles = stylex.create({
     gap: space.s2,
   },
   // As tall as the window controls beside it, with no rule: the header row
-  // of Desktop's Ask panel.
+  // of Desktop's Ask panel. At the window's right end, under the controls
+  // Windows and Linux draw there, its close button clears them.
   nativeHeader: {
     height: tokens.reviewPageBarHeight,
     minHeight: tokens.reviewPageBarHeight,
     borderBottomWidth: 0,
+    "--review-header-inset-right": "var(--review-chrome-right-width, 0px)",
   },
   // A conversation sits on the tray, header and all.
   tray: {