diff --git a/docs/design.md b/docs/design.md
index 8a2cae25ba..0437320c09 100644
--- a/docs/design.md
+++ b/docs/design.md
@@ -68,9 +68,11 @@ the sidebar. Apply it as `backgroundColor`; setting `opacity` on the control als
 
 `destructive` is filled with `destructive`. It only appears inside a confirm. The button on the page is `outline`; the destructive button is the confirm button inside the dialog.
 
-Controls come in two sizes, defined once in `control-geometry.ts`. The default is the right size almost everywhere — pages, dialogs, forms, settings rows, the setup flow — so don't pass a size. It is 32px tall where a pointer drives it and 44px in the compact layout, so every phone control is a full touch target; the breakpoint, not the caller, makes that choice. `sm` is 28px with `fontSize.sm` labels and is for tight chrome only: toolbars, nested settings rows, dense inline row actions. A `size="sm"` on an ordinary page or dialog is wrong, and so is choosing a size from `useIsCompactFormFactor()`.
+Controls come in two sizes, defined once in `control-geometry.ts`. The default is the right size almost everywhere — pages, dialogs, forms, settings rows, the setup flow — so don't pass a size. It is 32px tall where a pointer drives it and 44px where controls are touch-sized, so every touch control meets the iOS HIG's 44pt hit region. `sm` is 28px pointer and 32px touch, with `fontSize.sm` labels, and is for tight chrome only: toolbars, nested settings rows, dense inline row actions. A `size="sm"` on an ordinary page or dialog is wrong, and so is choosing a size from `useIsCompactFormFactor()`.
 
-Buttons are pills (`borderRadius.full`) with medium-weight labels; an icon-only button is a circle. `<Switch>` follows the same two sizes: a 34×20 track by default and in `sm`, 44×26 in the compact layout, and it reserves its size's control height so a row holding one lines up with a row holding a button. Buttons, text fields, dropdown triggers, and `<SegmentedControl>` (`packages/app/src/components/ui/segmented-control.tsx`) share the size contract — the same size name means the same height and label size on every control kind, so controls in one row line up. Segments run tighter than a button, because the gap between segments already reads as padding. The selected segment is a `surface3` fill with `foreground` text, not an inverted one — inverting it inside thin chrome puts a white slab in the toolbar. A settings row sizes the controls in its trailing slot itself, default in a card and `sm` when nested (`packages/app/src/components/ui/control-size.tsx`), so don't pass a size to a button, dropdown or field placed in a row. Code that computes with a control's height outside a stylesheet uses `controlHeightForLayout`. Never shrink a control's font or padding locally to fit a context — if the context needs a smaller control, the size tier is missing or the wrong one is in use.
+One gate, `resolveControlSizing`, picks touch or pointer sizing: touch when the layout is compact or the device has a touch screen. An iPad with the sidebar docked is wide and touch-sized; a desktop is pointer-sized; a phone is both compact and touch. The touch-screen fact is read once at startup (`hasTouchScreen` in `hooks/use-fine-pointer.ts`), so attaching a mouse or keyboard to a tablet never shrinks its controls. Stylesheets take sizes from `bySizing({ touch, pointer })`, which resolves to a breakpoint value, so a caller never sees which sizing it got. Rows, icon buttons and icon slots take theirs from `styles/density.ts`, which uses the same gate. An `{ xs, md }` literal for a hit target or glyph is wrong: on an iPad it yields the pointer size.
+
+Buttons are pills (`borderRadius.full`) with medium-weight labels; an icon-only button is a circle. `<Switch>` follows the same two sizes: a 34×20 track by default and in `sm`, 44×26 where controls are touch-sized, and it reserves its size's control height so a row holding one lines up with a row holding a button. Buttons, text fields, dropdown triggers, and `<SegmentedControl>` (`packages/app/src/components/ui/segmented-control.tsx`) share the size contract — the same size name means the same height and label size on every control kind, so controls in one row line up. Segments run tighter than a button, because the gap between segments already reads as padding. The selected segment is a `surface3` fill with `foreground` text, not an inverted one — inverting it inside thin chrome puts a white slab in the toolbar. A settings row sizes the controls in its trailing slot itself, default in a card and `sm` when nested (`packages/app/src/components/ui/control-size.tsx`), so don't pass a size to a button, dropdown or field placed in a row. Code that computes with a control's height outside a stylesheet uses `controlHeightForLayout`. Never shrink a control's font or padding locally to fit a context — if the context needs a smaller control, the size tier is missing or the wrong one is in use.
 
 A `<Pressable>` wrapping a `<Text>` is a sixth variant. It is wrong. `<Button>` accepts `style`, `textStyle`, `leftIcon`, `disabled`, `size`, and `variant`.
 
@@ -150,7 +152,7 @@ One row off the rail makes the whole card look unconsidered.
 
 Compact-first. The small case is designed; the large case adds chrome around it.
 
-Use `md: 600` for both the compact/wide layout boundary and responsive density, in logical points on native and CSS pixels on web. Do not add a separate density breakpoint. Measured content constraints remain independent: composer controls use `COMPACT_CONTENT_WIDTH` (500), so a narrow pane can keep compact controls inside a wide window.
+Use `md: 600` for the compact/wide layout boundary, in logical points on native and CSS pixels on web. Do not add a separate density breakpoint; touch sizing comes from the control sizing gate in [Buttons](#4-buttons). Measured content constraints remain independent: composer controls use `COMPACT_CONTENT_WIDTH` (500), so a narrow pane can keep compact controls inside a wide window.
 
 The settings shell (`packages/app/src/screens/settings-screen.tsx`) and the projects screen (`packages/app/src/screens/projects-screen.tsx`) share the canonical list+detail navigation pattern:
 
diff --git a/packages/app/e2e/browser/changes-pane.spec.ts b/packages/app/e2e/browser/changes-pane.spec.ts
index 1ff6059460..aa884c66e9 100644
--- a/packages/app/e2e/browser/changes-pane.spec.ts
+++ b/packages/app/e2e/browser/changes-pane.spec.ts
@@ -928,11 +928,11 @@ test("compact Changes keeps its actions compact and menu-only", async ({ page })
     throw new Error("Compact Changes toolbar geometry could not be measured");
   }
   expect(actionsBox.width).toBe(48);
-  expect(actionsBox.height).toBe(28);
-  expect(optionsBox.width).toBe(32);
-  expect(optionsBox.height).toBe(32);
-  expect(glyphBox.width).toBe(18);
-  expect(glyphBox.height).toBe(18);
+  expect(actionsBox.height).toBe(32);
+  expect(optionsBox.width).toBe(44);
+  expect(optionsBox.height).toBe(44);
+  expect(glyphBox.width).toBe(20);
+  expect(glyphBox.height).toBe(20);
 
   await expect(actions).not.toContainText("Commit");
   await expect(actions.locator("svg")).toHaveCount(2);
diff --git a/packages/app/e2e/browser/composer-control-density.spec.ts b/packages/app/e2e/browser/composer-control-density.spec.ts
index 9c81037526..ebd9717feb 100644
--- a/packages/app/e2e/browser/composer-control-density.spec.ts
+++ b/packages/app/e2e/browser/composer-control-density.spec.ts
@@ -5,6 +5,7 @@ import {
   recordComposerToolbarFrames,
 } from "../support/helpers/composer-control-density";
 import { clickNewChat, gotoWorkspace } from "../support/helpers/launcher";
+import { openAgentRoute, seedMockAgentWorkspace } from "../support/helpers/mock-agent";
 import { seedWorkspace, type SeededWorkspace } from "../support/helpers/seed-client";
 
 const SETTLE_MS = 1_000;
@@ -92,3 +93,34 @@ test.describe("Composer control density across tab switches", () => {
     }
   });
 });
+
+test.describe("Composer controls folding on a touch device", () => {
+  test.use({ viewport: { width: 1194, height: 834 }, isMobile: true, hasTouch: true });
+  test.describe.configure({ timeout: 180_000 });
+
+  test("an open menu stays closed after the controls fold and unfold", async ({ page }) => {
+    const session = await seedMockAgentWorkspace({
+      repoPrefix: "composer-density-fold-",
+      title: "Folding chat",
+      model: "ten-second-stream",
+    });
+    try {
+      await openAgentRoute(page, session);
+      const thinking = page.getByTestId("agent-thinking-selector").filter({ visible: true });
+      const thinkingMenu = page.getByTestId("combobox-desktop-container");
+
+      await thinking.click();
+      await expect(thinkingMenu).toBeVisible();
+
+      // Still a wide layout, but too narrow for separate controls: they fold into the model control.
+      await page.setViewportSize({ width: 640, height: 834 });
+      await expect(thinking).toHaveCount(0);
+
+      await page.setViewportSize({ width: 1194, height: 834 });
+      await expect(thinking).toBeVisible();
+      await expect(thinkingMenu).toHaveCount(0);
+    } finally {
+      await session.cleanup();
+    }
+  });
+});
diff --git a/packages/app/e2e/browser/plugin-sidebar-items.spec.ts b/packages/app/e2e/browser/plugin-sidebar-items.spec.ts
index dfba0ec816..e91b6a55da 100644
--- a/packages/app/e2e/browser/plugin-sidebar-items.spec.ts
+++ b/packages/app/e2e/browser/plugin-sidebar-items.spec.ts
@@ -317,7 +317,10 @@ test.describe("Plugin sidebar items", () => {
       const compactSync = footerItem(page, SHOWCASE_PLUGIN_ID, "sync");
       await expect(compactSync).toBeInViewport();
       await expectFooterRow(page, compactSync);
-      await expect(headerRow(page, SHOWCASE_PLUGIN_ID, "deploys")).toBeInViewport();
+      // The compact nav block is capped at half the sidebar and scrolls past it.
+      const compactDeploys = headerRow(page, SHOWCASE_PLUGIN_ID, "deploys");
+      await compactDeploys.scrollIntoViewIfNeeded();
+      await expect(compactDeploys).toBeInViewport();
       await qaScreenshot(page, "phase2-compact-sidebar");
       await qaScreenshot(page, "phase5-compact-footer", sidebarFooter(page));
       await compactSync.click();
diff --git a/packages/app/src/components/combined-model-selector.tsx b/packages/app/src/components/combined-model-selector.tsx
index 8473760c92..2f6ab0137e 100644
--- a/packages/app/src/components/combined-model-selector.tsx
+++ b/packages/app/src/components/combined-model-selector.tsx
@@ -13,6 +13,7 @@ import { useIsCompactFormFactor } from "@/constants/layout";
 import { isNative, isWeb } from "@/constants/platform";
 import type { ProviderSelectorProvider } from "@/provider-selection/provider-selection";
 import { ICON_SIZE, type Theme } from "@/styles/theme";
+import { TOOLBAR_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 
 const EMPTY_COMBOBOX_OPTIONS: ComboboxOption[] = [];
 const ThemedLoadingSpinner = withUnistyles(LoadingSpinner);
@@ -292,7 +293,7 @@ const styles = StyleSheet.create((theme) => ({
     paddingHorizontal: 0,
   },
   trigger: {
-    height: 28,
+    height: TOOLBAR_CONTROL_HEIGHT,
     minWidth: 0,
     flexShrink: 1,
     flexDirection: "row",
diff --git a/packages/app/src/components/context-window-meter.tsx b/packages/app/src/components/context-window-meter.tsx
index 32c739c073..4d78ea7592 100644
--- a/packages/app/src/components/context-window-meter.tsx
+++ b/packages/app/src/components/context-window-meter.tsx
@@ -9,6 +9,7 @@ import { useIsCompactFormFactor } from "@/constants/layout";
 import { isNative } from "@/constants/platform";
 import { useHostReportsUsage } from "@/usage";
 import type { Theme } from "@/styles/theme";
+import { TOOLBAR_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 import { ContextWindowDetails } from "./context-window-details";
 import { ContextWindowSheet } from "./context-window-sheet";
 import { formatContextPercentage } from "./context-window-meter.utils";
@@ -306,14 +307,14 @@ export function ContextWindowMeter({
 
 const styles = StyleSheet.create((theme) => ({
   container: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     borderRadius: theme.borderRadius.full,
     alignItems: "center",
     justifyContent: "center",
   },
   containerWithLabel: {
-    height: 28,
+    height: TOOLBAR_CONTROL_HEIGHT,
     flexDirection: "row",
     alignItems: "center",
     justifyContent: "center",
diff --git a/packages/app/src/components/settings/row-density.tsx b/packages/app/src/components/settings/row-density.tsx
index 8a52d6cdab..3682899624 100644
--- a/packages/app/src/components/settings/row-density.tsx
+++ b/packages/app/src/components/settings/row-density.tsx
@@ -1,7 +1,7 @@
 import { createContext, useContext, useMemo, type ReactNode } from "react";
 import type { StyleProp, TextStyle, ViewStyle } from "react-native";
 import { StyleSheet } from "react-native-unistyles";
-import { CONTROL_HEIGHTS, type ControlSize } from "@/components/ui/control-geometry";
+import { CONTROL_HEIGHTS, mapLayout, type ControlSize } from "@/components/ui/control-geometry";
 
 import { settingsStyles } from "@/styles/settings";
 
@@ -49,7 +49,7 @@ const styles = StyleSheet.create((theme) => ({
   // trailing button line up.
   nestedRow: {
     paddingVertical: theme.spacing[2],
-    minHeight: CONTROL_HEIGHTS.sm + theme.spacing[2] * 2,
+    minHeight: mapLayout(CONTROL_HEIGHTS.sm, (height) => height + theme.spacing[2] * 2),
   },
   nestedText: {
     fontSize: theme.fontSize.sm,
diff --git a/packages/app/src/components/sidebar-workspace-list.tsx b/packages/app/src/components/sidebar-workspace-list.tsx
index 8697a4b27b..5000e1f067 100644
--- a/packages/app/src/components/sidebar-workspace-list.tsx
+++ b/packages/app/src/components/sidebar-workspace-list.tsx
@@ -154,6 +154,7 @@ import type { HostBadgeModel } from "@/hosts/appearance";
 import { useHostBadges } from "@/hosts/use-host-badges";
 import { useSidebarRowItems } from "@/components/sidebar/display-preferences/model";
 import { PullRequestStateIcon } from "@/git/pull-request-state-icon";
+import { bySizing } from "@/components/ui/control-geometry";
 
 const workspaceKeyExtractor = (workspace: SidebarWorkspacePlacement) => workspace.workspaceKey;
 
@@ -2737,12 +2738,12 @@ const styles = StyleSheet.create((theme) => ({
     marginRight: -6,
   },
   projectKebabButton: {
-    // Larger on compact so the kebab is an easy tap target. The negative margins keep its
-    // dots on the same rail as the 24px desktop box and the row at its 44px height.
-    width: { xs: 32, md: 24 },
-    height: { xs: 32, md: 24 },
-    marginRight: { xs: -4, md: 0 },
-    marginVertical: { xs: -4, md: 0 },
+    // Larger on touch so the kebab is an easy tap target. The negative margins keep its
+    // dots on the same rail as the 24px pointer box and the row at its 44px height.
+    width: bySizing({ touch: 32, pointer: 24 }),
+    height: bySizing({ touch: 32, pointer: 24 }),
+    marginRight: bySizing({ touch: -4, pointer: 0 }),
+    marginVertical: bySizing({ touch: -4, pointer: 0 }),
     borderRadius: theme.borderRadius.md,
     alignItems: "center",
     justifyContent: "center",
diff --git a/packages/app/src/components/sidebar/sidebar-workspace-menu.tsx b/packages/app/src/components/sidebar/sidebar-workspace-menu.tsx
index f74c43c980..64a3099047 100644
--- a/packages/app/src/components/sidebar/sidebar-workspace-menu.tsx
+++ b/packages/app/src/components/sidebar/sidebar-workspace-menu.tsx
@@ -36,6 +36,7 @@ import {
 import { Shortcut } from "@/components/ui/shortcut";
 import { OpenInFileManagerMenuItem } from "@/workspace/open-in-file-manager/menu-item";
 import { resolveSidebarWorkspaceAccessibilityLabel } from "@/components/sidebar/sidebar-workspace-title";
+import { bySizing } from "@/components/ui/control-geometry";
 import {
   workspaceServiceLabelKey,
   type WorkspaceServiceSummary,
@@ -438,18 +439,18 @@ function triggerStyle({ hovered = false }: PressableStateCallbackType & { hovere
 
 const styles = StyleSheet.create((theme) => ({
   trigger: {
-    // Larger on compact so the kebab is an easy tap target.
-    width: { xs: 32, md: 18 },
-    height: { xs: 32, md: 18 },
+    // Larger on touch so the kebab is an easy tap target.
+    width: bySizing({ touch: 32, pointer: 18 }),
+    height: bySizing({ touch: 32, pointer: 18 }),
     alignItems: "center",
     justifyContent: "center",
     borderRadius: 4,
     marginLeft: 2,
-    // Center the compact box on the 20px title line it is anchored to.
-    marginTop: { xs: -6, md: 0 },
+    // Center the touch box on the 20px title line it is anchored to.
+    marginTop: bySizing({ touch: -6, pointer: 0 }),
     // MoreVertical paints only around the center of its SVG. Keep the padded hit box, but
     // pull the painted dots through that unused view-box space onto the trailing-content rail.
-    marginRight: { xs: -14, md: -7 },
+    marginRight: bySizing({ touch: -14, pointer: -7 }),
   },
   triggerHovered: {
     backgroundColor: theme.colors.surface2,
diff --git a/packages/app/src/components/ui/combobox.tsx b/packages/app/src/components/ui/combobox.tsx
index 5a2da0a365..cee4fc2dea 100644
--- a/packages/app/src/components/ui/combobox.tsx
+++ b/packages/app/src/components/ui/combobox.tsx
@@ -64,6 +64,8 @@ import {
 import { FloatingSurface } from "@/components/ui/floating";
 import { useDismissKeyboardOnOpen } from "@/components/ui/keyboard-dismiss";
 import { getOverlayRoot, OverlayLayerProvider, useOverlayLayer } from "@/lib/overlay-root";
+import { density, densityIconBox } from "@/styles/density";
+import { DensityIcon } from "@/components/ui/density-icon";
 import { buildDesktopFrameStyle } from "./combobox-frame-style";
 
 export { buildDesktopFrameStyle } from "./combobox-frame-style";
@@ -203,7 +205,7 @@ export function SearchInput({
 
   return (
     <View style={styles.searchInputContainer}>
-      <Search size={16} color={theme.colors.foregroundMuted} />
+      <DensityIcon icon={Search} size="md" color="foregroundMuted" />
       <AdaptiveTextInput
         ref={inputRef}
         // @ts-expect-error - outlineStyle is web-only
@@ -250,21 +252,19 @@ export function ComboboxItem({
   onPress,
   testID,
 }: ComboboxItemProps): ReactElement {
-  const { theme } = useUnistyles();
-
   let leadingContent: ReactElement | null = null;
   if (leadingSlot) {
     leadingContent = <View style={styles.comboboxItemLeadingSlot}>{leadingSlot}</View>;
   } else if (kind === "directory") {
     leadingContent = (
       <View style={styles.comboboxItemLeadingSlot}>
-        <Folder size={16} color={theme.colors.foregroundMuted} />
+        <DensityIcon icon={Folder} size="md" color="foregroundMuted" />
       </View>
     );
   } else if (kind === "file") {
     leadingContent = (
       <View style={styles.comboboxItemLeadingSlot}>
-        <File size={16} color={theme.colors.foregroundMuted} />
+        <DensityIcon icon={File} size="md" color="foregroundMuted" />
       </View>
     );
   }
@@ -308,7 +308,7 @@ export function ComboboxItem({
       {selected || trailingSlot ? (
         <View style={styles.comboboxItemTrailingContainer}>
           <View style={styles.comboboxItemTrailingSlot}>
-            {selected ? <Check size={16} color={theme.colors.foregroundMuted} /> : null}
+            {selected ? <DensityIcon icon={Check} size="md" color="foregroundMuted" /> : null}
           </View>
           {trailingSlot}
         </View>
@@ -1682,7 +1682,7 @@ const styles = StyleSheet.create((theme) => ({
   comboboxItem: {
     flexDirection: "row",
     alignItems: "center",
-    minHeight: 36,
+    minHeight: density.rowHeight,
     gap: theme.spacing[2],
     paddingHorizontal: theme.spacing[3],
     paddingVertical: theme.spacing[2],
@@ -1713,7 +1713,7 @@ const styles = StyleSheet.create((theme) => ({
     opacity: 0.55,
   },
   comboboxItemTrailingSlot: {
-    width: 16,
+    width: densityIconBox("md"),
     alignItems: "center",
     justifyContent: "center",
   },
@@ -1733,7 +1733,7 @@ const styles = StyleSheet.create((theme) => ({
     gap: theme.spacing[2],
   },
   comboboxItemLeadingSlot: {
-    width: 16,
+    width: densityIconBox("md"),
     alignItems: "center",
     justifyContent: "center",
   },
diff --git a/packages/app/src/components/ui/control-geometry.test.ts b/packages/app/src/components/ui/control-geometry.test.ts
index dc39cdf596..90b18d6029 100644
--- a/packages/app/src/components/ui/control-geometry.test.ts
+++ b/packages/app/src/components/ui/control-geometry.test.ts
@@ -1,11 +1,20 @@
 import { describe, expect, it } from "vitest";
 import {
   ALERT_ICON_SIZE,
+  bySizing,
   CONTROL_HEIGHTS,
   controlHeightForLayout,
+  controlSizingForLayout,
   createControlGeometry,
+  HEADER_CONTROL_HEIGHT,
+  ICON_BUTTON_SIZES,
+  iconSizeFor,
+  resolveControlSizing,
   switchGeometryForLayout,
   getControlInteractionPhase,
+  TOOLBAR_CONTROL_HEIGHT,
+  TOOLBAR_CONTROL_SIZES,
+  TOUCH_TARGET,
 } from "@/components/ui/control-geometry";
 import type { Theme } from "@/styles/theme";
 
@@ -47,6 +56,52 @@ const theme = {
   },
 } as unknown as Theme;
 
+describe("control sizing gate", () => {
+  it("is touch-sized in the compact layout or on a touch screen, and pointer-sized otherwise", () => {
+    expect(resolveControlSizing({ compactLayout: true, touchScreen: true })).toBe("touch");
+    expect(resolveControlSizing({ compactLayout: true, touchScreen: false })).toBe("touch");
+    expect(resolveControlSizing({ compactLayout: false, touchScreen: true })).toBe("touch");
+    expect(resolveControlSizing({ compactLayout: false, touchScreen: false })).toBe("pointer");
+  });
+
+  it("gives a touch screen its touch sizes at every width", () => {
+    const sizes = { touch: 44, pointer: 32 };
+
+    // An iPad: touch-sized in the docked desktop layout too.
+    expect(bySizing(sizes, true)).toEqual({ xs: 44, md: 44 });
+    // A mouse-driven window: touch-sized only once it narrows into the compact layout.
+    expect(bySizing(sizes, false)).toEqual({ xs: 44, md: 32 });
+  });
+
+  it("keeps a device without a touch screen on pointer sizes from md up", () => {
+    // The unit runtime has no touch screen, which is the desktop that must not change.
+    expect(controlSizingForLayout(false)).toBe("pointer");
+    expect(controlSizingForLayout(true)).toBe("touch");
+    expect(CONTROL_HEIGHTS.md).toEqual({ xs: 44, md: 32 });
+    expect(CONTROL_HEIGHTS.sm).toEqual({ xs: 32, md: 28 });
+    expect(HEADER_CONTROL_HEIGHT).toEqual({ xs: 32, md: 26 });
+  });
+
+  it("follows the HIG on touch: a 44pt target, no control under 28pt, larger glyphs", () => {
+    expect(TOUCH_TARGET).toBe(44);
+    expect(controlHeightForLayout("md", true)).toBe(TOUCH_TARGET);
+    expect(ICON_BUTTON_SIZES.large.touch).toBe(TOUCH_TARGET);
+    expect(ICON_BUTTON_SIZES.small.touch).toBe(TOUCH_TARGET);
+    // Composer toolbar controls: a full target on touch, unchanged 28 on pointer.
+    expect(TOOLBAR_CONTROL_SIZES).toEqual({ touch: TOUCH_TARGET, pointer: 28 });
+    expect(TOOLBAR_CONTROL_HEIGHT).toEqual({ xs: TOUCH_TARGET, md: 28 });
+    for (const size of ["sm", "md"] as const) {
+      expect(controlHeightForLayout(size, true)).toBeGreaterThan(
+        controlHeightForLayout(size, false),
+      );
+      expect(controlHeightForLayout(size, false)).toBeGreaterThanOrEqual(28);
+    }
+    for (const size of ["xs", "sm", "md", "lg"] as const) {
+      expect(iconSizeFor(size).touch).toBeGreaterThan(iconSizeFor(size).pointer);
+    }
+  });
+});
+
 describe("control geometry", () => {
   it("keeps resting control borders transparent while preserving border geometry", () => {
     const geometry = createControlGeometry(theme);
@@ -98,18 +153,17 @@ describe("control geometry", () => {
     const geometry = createControlGeometry(theme);
     const borderWidth = theme.borderWidth[1];
 
-    expect(geometry.fieldControlSm.minHeight).toBe(28);
-    expect(
-      geometry.fieldTextSm.lineHeight +
-        geometry.fieldControlSm.paddingVertical * 2 +
-        borderWidth * 2,
-    ).toBe(geometry.fieldControlSm.minHeight);
-
+    expect(geometry.fieldControlSm.minHeight).toEqual({ xs: 32, md: 28 });
     // The default keeps a 44 touch target in the compact layout and is 32 from the md
     // breakpoint up.
     expect(geometry.fieldControlMd.minHeight).toEqual({ xs: 44, md: 32 });
     expect(geometry.fieldControlMd.paddingVertical).toEqual({ xs: 11, md: 5 });
     for (const layout of ["xs", "md"] as const) {
+      expect(
+        geometry.fieldTextSm.lineHeight +
+          geometry.fieldControlSm.paddingVertical[layout] * 2 +
+          borderWidth * 2,
+      ).toBe(geometry.fieldControlSm.minHeight[layout]);
       expect(
         geometry.fieldTextMd.lineHeight +
           geometry.fieldControlMd.paddingVertical[layout] * 2 +
@@ -125,24 +179,25 @@ describe("control geometry", () => {
     expect(geometry.segmentedContainerMd.padding).toBe(0);
     expect(geometry.segmentedSegmentSm.borderRadius).toBe(geometry.buttonSm.borderRadius);
     expect(geometry.segmentedSegmentMd.borderRadius).toBe(geometry.buttonMd.borderRadius);
-    expect(geometry.segmentedContainerSm.minHeight).toBe(geometry.buttonSm.minHeight);
+    expect(geometry.segmentedContainerSm.minHeight).toEqual(geometry.buttonSm.minHeight);
     expect(geometry.segmentedContainerMd.minHeight).toEqual(geometry.buttonMd.minHeight);
-    expect(geometry.segmentedSegmentSm.minHeight).toBe(24);
+    expect(geometry.segmentedSegmentSm.minHeight).toEqual({ xs: 28, md: 24 });
     expect(geometry.segmentedSegmentMd.minHeight).toEqual({ xs: 40, md: 28 });
   });
 
   it("keeps one size contract across buttons, fields, and segmented controls", () => {
     const geometry = createControlGeometry(theme);
 
-    expect(geometry.buttonSm.minHeight).toBe(28);
+    expect(geometry.buttonSm.minHeight).toEqual({ xs: 32, md: 28 });
     expect(geometry.buttonMd.minHeight).toEqual({ xs: 44, md: 32 });
-    expect(geometry.buttonSm.minHeight).toBe(CONTROL_HEIGHTS.sm);
+    expect(geometry.buttonSm.minHeight).toEqual(CONTROL_HEIGHTS.sm);
     expect(geometry.buttonMd.minHeight).toEqual(CONTROL_HEIGHTS.md);
-    expect(geometry.fieldControlSm.minHeight).toBe(CONTROL_HEIGHTS.sm);
+    expect(geometry.fieldControlSm.minHeight).toEqual(CONTROL_HEIGHTS.sm);
     expect(geometry.fieldControlMd.minHeight).toEqual(CONTROL_HEIGHTS.md);
     expect(controlHeightForLayout("md", true)).toBe(44);
     expect(controlHeightForLayout("md", false)).toBe(32);
-    expect(controlHeightForLayout("sm", true)).toBe(28);
+    expect(controlHeightForLayout("sm", true)).toBe(32);
+    expect(controlHeightForLayout("sm", false)).toBe(28);
 
     // Same size name means the same label size on every control kind.
     expect(geometry.segmentedLabelSm.fontSize).toBe(12);
@@ -177,13 +232,15 @@ describe("control geometry", () => {
       thumbTravel: 18,
       reservedHeight: 44,
     });
-    // Tight chrome keeps the pointer-sized switch on every layout.
-    for (const isCompact of [true, false]) {
-      expect(switchGeometryForLayout("sm", isCompact)).toMatchObject({
-        trackWidth: 34,
-        reservedHeight: 28,
-      });
-    }
+    // Tight chrome keeps the pointer-sized track on every layout and reserves its row's height.
+    expect(switchGeometryForLayout("sm", true)).toMatchObject({
+      trackWidth: 34,
+      reservedHeight: 32,
+    });
+    expect(switchGeometryForLayout("sm", false)).toMatchObject({
+      trackWidth: 34,
+      reservedHeight: 28,
+    });
   });
 
   it("gives alert title and description one font size and a tight gap per size", () => {
diff --git a/packages/app/src/components/ui/control-geometry.ts b/packages/app/src/components/ui/control-geometry.ts
index ef2f6a7a72..407c042cbe 100644
--- a/packages/app/src/components/ui/control-geometry.ts
+++ b/packages/app/src/components/ui/control-geometry.ts
@@ -1,5 +1,14 @@
 import type { StyleProp, ViewStyle } from "react-native";
 import { ICON_SIZE, type Theme } from "@/styles/theme";
+import {
+  bySizing,
+  controlSizingForLayout,
+  mapLayout,
+  TOUCH_TARGET,
+  type ControlSizing,
+  type LayoutValue,
+  type SizingValue,
+} from "./control-sizing";
 
 /**
  * Controls come in two sizes. `md` is the default and the right size almost everywhere;
@@ -26,46 +35,78 @@ export interface ControlInteractionStyleMap {
   controlDisabled?: StyleProp<ViewStyle>;
 }
 
-const SMALL_CONTROL_HEIGHT = 28;
-// The default control keeps a full touch target in the compact layout and tightens where a
-// pointer drives it.
-const DEFAULT_CONTROL_HEIGHT_COMPACT_LAYOUT = 44;
-const DEFAULT_CONTROL_HEIGHT_WIDE_LAYOUT = 32;
-export const HEADER_CONTROL_HEIGHT = 26;
+export {
+  bySizing,
+  controlSizingForLayout,
+  mapLayout,
+  resolveControlSizing,
+  TOUCH_TARGET,
+  type ControlSizing,
+  type ControlSizingFacts,
+  type LayoutValue,
+  type SizingValue,
+} from "./control-sizing";
+
+// Touch `md` is the iOS HIG's 44pt default control; touch `sm` stays above its 28pt minimum.
+const CONTROL_SIZES = {
+  sm: { touch: 32, pointer: 28 },
+  md: { touch: TOUCH_TARGET, pointer: 32 },
+} satisfies Record<ControlSize, SizingValue>;
+
+/** Pointer-sized header controls run tighter than `sm` so they fit the 36pt header. */
+const POINTER_HEADER_CONTROL_HEIGHT = 26;
 const SEGMENTED_INSET = 2;
 const CONTROL_FOCUS_RING_WIDTH = 2;
 const CONTROL_FOCUS_RING_OFFSET = 1;
 const FIELD_TEXT_LINE_HEIGHT_RATIO = 1.4;
 
-/** A Unistyles breakpoint value: one number in the compact layout, another from `md` up. */
-// A mapped type, not an interface: Unistyles checks breakpoint objects against an index
-// signature, which interfaces never satisfy.
-export type LayoutValue = Record<"xs" | "md", number>;
-
-function byLayout(compact: number, wide: number): LayoutValue {
-  return { xs: compact, md: wide };
-}
-
-function mapLayout(value: LayoutValue, map: (height: number) => number): LayoutValue {
-  return byLayout(map(value.xs), map(value.md));
-}
-
 /**
  * The height of every button, field, and segmented control of a size. Exported so a row that
  * hosts one of those controls can size itself from the same numbers instead of guessing a
- * height the control then outgrows. `md` depends on the layout, so it only works inside a
- * Unistyles stylesheet.
+ * height the control then outgrows. Breakpoint values, so they only work inside a Unistyles
+ * stylesheet.
  */
 export const CONTROL_HEIGHTS = {
-  sm: SMALL_CONTROL_HEIGHT,
-  md: byLayout(DEFAULT_CONTROL_HEIGHT_COMPACT_LAYOUT, DEFAULT_CONTROL_HEIGHT_WIDE_LAYOUT),
-} satisfies Record<ControlSize, number | LayoutValue>;
+  sm: bySizing(CONTROL_SIZES.sm),
+  md: bySizing(CONTROL_SIZES.md),
+} satisfies Record<ControlSize, LayoutValue>;
+
+/** A framed control in a header row, such as a split button. Touch-sized it is an `sm` control. */
+export const HEADER_CONTROL_HEIGHT = bySizing({
+  touch: CONTROL_SIZES.sm.touch,
+  pointer: POINTER_HEADER_CONTROL_HEIGHT,
+});
+
+/**
+ * Square icon-only buttons. Touch-sized, every icon button is one touch target; pointer-sized,
+ * header buttons are larger than toolbar buttons.
+ */
+export const ICON_BUTTON_SIZES = {
+  large: { touch: TOUCH_TARGET, pointer: POINTER_HEADER_CONTROL_HEIGHT },
+  small: { touch: TOUCH_TARGET, pointer: 20 },
+} satisfies Record<"large" | "small", SizingValue>;
+
+/**
+ * A control in a dense toolbar row, such as the composer's: an icon-only square or a labelled
+ * pill. Touch-sized it is one touch target.
+ */
+export const TOOLBAR_CONTROL_SIZES = { touch: TOUCH_TARGET, pointer: 28 } satisfies SizingValue;
+export const TOOLBAR_CONTROL_HEIGHT = bySizing(TOOLBAR_CONTROL_SIZES);
+
+/**
+ * Glyph sizes. Pointer glyphs sit beside 13-14pt text; touch glyphs sit beside iOS's 17pt body
+ * text, so each step is larger.
+ */
+export type IconSize = keyof typeof ICON_SIZE;
+export const TOUCH_ICON_SIZE: Record<IconSize, number> = { xs: 14, sm: 18, md: 20, lg: 24 };
+
+export function iconSizeFor(size: IconSize): SizingValue {
+  return { touch: TOUCH_ICON_SIZE[size], pointer: ICON_SIZE[size] };
+}
 
 /** The height of a control of `size`, for code that has to compute with it outside a stylesheet. */
 export function controlHeightForLayout(size: ControlSize, isCompact: boolean): number {
-  const height = CONTROL_HEIGHTS[size];
-  if (typeof height === "number") return height;
-  return isCompact ? height.xs : height.md;
+  return CONTROL_SIZES[size][controlSizingForLayout(isCompact)];
 }
 
 export const controlIconSize: Record<ControlSize, number> = {
@@ -96,7 +137,8 @@ const SWITCH_TOUCH = switchSize(44, 26, 22);
  * animation, so the size is resolved to plain numbers here instead of a stylesheet breakpoint.
  */
 export function switchGeometryForLayout(size: ControlSize, isCompact: boolean): SwitchGeometry {
-  const track = size === "md" && isCompact ? SWITCH_TOUCH : SWITCH_POINTER;
+  const touchSized = controlSizingForLayout(isCompact) === "touch";
+  const track = size === "md" && touchSized ? SWITCH_TOUCH : SWITCH_POINTER;
   return { ...track, reservedHeight: controlHeightForLayout(size, isCompact) };
 }
 
@@ -225,10 +267,8 @@ export function createControlGeometry(theme: Theme) {
   const fieldControlSm = {
     minHeight: CONTROL_HEIGHTS.sm,
     paddingHorizontal: theme.spacing[2],
-    paddingVertical: fieldVerticalPadding(
-      CONTROL_HEIGHTS.sm,
-      fieldTextSmLineHeight,
-      controlBorderWidth,
+    paddingVertical: mapLayout(CONTROL_HEIGHTS.sm, (height) =>
+      fieldVerticalPadding(height, fieldTextSmLineHeight, controlBorderWidth),
     ),
     borderRadius: theme.borderRadius.md,
   };
@@ -258,7 +298,7 @@ export function createControlGeometry(theme: Theme) {
     },
     buttonMd: {
       minHeight: CONTROL_HEIGHTS.md,
-      paddingHorizontal: byLayout(theme.spacing[6], theme.spacing[4]),
+      paddingHorizontal: bySizing({ touch: theme.spacing[6], pointer: theme.spacing[4] }),
       borderRadius: theme.borderRadius.full,
     },
     // A button with only an icon is a circle of its size's height.
@@ -314,7 +354,7 @@ export function createControlGeometry(theme: Theme) {
       padding: 0,
     },
     segmentedSegmentSm: {
-      minHeight: CONTROL_HEIGHTS.sm - SEGMENTED_INSET * 2,
+      minHeight: mapLayout(CONTROL_HEIGHTS.sm, (height) => height - SEGMENTED_INSET * 2),
       paddingHorizontal: theme.spacing[2],
       borderRadius: theme.borderRadius.full,
     },
diff --git a/packages/app/src/components/ui/control-sizing.ts b/packages/app/src/components/ui/control-sizing.ts
new file mode 100644
index 0000000000..d64fc3f000
--- /dev/null
+++ b/packages/app/src/components/ui/control-sizing.ts
@@ -0,0 +1,68 @@
+import { hasTouchScreen } from "@/hooks/use-fine-pointer";
+
+// The sizing gate, apart from the control sizes so that low-level modules such as
+// `constants/layout` can size by it without loading the theme. Import it through
+// `@/components/ui/control-geometry`, which re-exports it.
+
+/**
+ * Every size comes in a touch value and a pointer value. Touch values follow Apple's Human
+ * Interface Guidelines for iOS and iPadOS: a 44pt default control and hit region, nothing
+ * smaller than its 28pt minimum. Pointer values sit one step down the same button ladder.
+ */
+export type ControlSizing = "touch" | "pointer";
+
+export interface ControlSizingFacts {
+  /** The layout is below the `md` breakpoint. */
+  compactLayout: boolean;
+  /** The device has a touch screen; see `hasTouchScreen`. */
+  touchScreen: boolean;
+}
+
+/**
+ * The one sizing gate: touch-sized in the compact layout or on any device with a touch screen,
+ * pointer-sized otherwise. A touch screen keeps touch sizing when a mouse or keyboard is attached.
+ */
+export function resolveControlSizing({
+  compactLayout,
+  touchScreen,
+}: ControlSizingFacts): ControlSizing {
+  if (compactLayout || touchScreen) return "touch";
+  return "pointer";
+}
+
+// Read once, so attaching a mouse or keyboard later never flips the sizing.
+const DEVICE_HAS_TOUCH_SCREEN = hasTouchScreen();
+
+/** The sizing on this device for a layout, for code that sizes outside a stylesheet. */
+export function controlSizingForLayout(compactLayout: boolean): ControlSizing {
+  return resolveControlSizing({ compactLayout, touchScreen: DEVICE_HAS_TOUCH_SCREEN });
+}
+
+/** A Unistyles breakpoint value: one number in the compact layout, another from `md` up. */
+// A mapped type, not an interface: Unistyles checks breakpoint objects against an index
+// signature, which interfaces never satisfy.
+export type LayoutValue = Record<"xs" | "md", number>;
+
+export type SizingValue = Record<ControlSizing, number>;
+
+/**
+ * A size as a Unistyles breakpoint value. The compact layout always takes the touch value; from
+ * `md` up the device decides.
+ */
+export function bySizing(
+  sizes: SizingValue,
+  touchScreen: boolean = DEVICE_HAS_TOUCH_SCREEN,
+): LayoutValue {
+  return {
+    xs: sizes[resolveControlSizing({ compactLayout: true, touchScreen })],
+    md: sizes[resolveControlSizing({ compactLayout: false, touchScreen })],
+  };
+}
+
+/** Derives a breakpoint value from another, such as a row as tall as its control plus padding. */
+export function mapLayout(value: LayoutValue, map: (height: number) => number): LayoutValue {
+  return { xs: map(value.xs), md: map(value.md) };
+}
+
+/** The smallest touch target, and the size of every touch-sized icon button, row, and bar. */
+export const TOUCH_TARGET = 44;
diff --git a/packages/app/src/components/ui/icon-button-chrome.ts b/packages/app/src/components/ui/icon-button-chrome.ts
index 75735ac986..42ba47a80a 100644
--- a/packages/app/src/components/ui/icon-button-chrome.ts
+++ b/packages/app/src/components/ui/icon-button-chrome.ts
@@ -1,17 +1,24 @@
 import { createContext, useCallback, useContext } from "react";
 import type { StyleProp, ViewStyle } from "react-native";
 import { StyleSheet } from "react-native-unistyles";
-import { HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
+import {
+  bySizing,
+  controlSizingForLayout,
+  ICON_BUTTON_SIZES,
+  TOUCH_ICON_SIZE,
+  type SizingValue,
+} from "@/components/ui/control-geometry";
 import { ICON_SIZE } from "@/styles/theme";
 
 export { extraMutedIconColorMapping, mutedIconColorMapping } from "@/components/ui/icon-color";
 
 export type IconButtonChromeSize = "large" | "small";
 
-const SMALL_ICON_BUTTON_SIZE = 20;
-/** Width and height of a large icon button on compact layouts. */
-export const COMPACT_LARGE_ICON_BUTTON_SIZE = 32;
-const COMPACT_SMALL_ICON_BUTTON_SIZE = 32;
+// Touch-sized, every icon button is one target with one glyph size.
+const GLYPH_SIZES = {
+  large: { touch: TOUCH_ICON_SIZE.md, pointer: ICON_SIZE.md },
+  small: { touch: TOUCH_ICON_SIZE.md, pointer: ICON_SIZE.sm },
+} satisfies Record<IconButtonChromeSize, SizingValue>;
 
 export interface IconButtonChromeState {
   hovered?: boolean;
@@ -22,7 +29,7 @@ export interface IconButtonChromeState {
 
 function resolveIconButtonFrame(size: IconButtonChromeSize, compact: boolean) {
   if (size === "large") return styles.large;
-  return compact ? styles.smallCompact : styles.small;
+  return controlSizingForLayout(compact) === "touch" ? styles.smallTouch : styles.small;
 }
 
 interface IconButtonChromeOptions {
@@ -92,24 +99,17 @@ export function iconButtonChromeFrameStyle(
 }
 
 export function iconButtonChromeGlyphSize(size: IconButtonChromeSize, compact = false): number {
-  if (size === "large") return ICON_SIZE.md;
-  return compact ? 18 : 14;
+  return GLYPH_SIZES[size][controlSizingForLayout(compact)];
 }
 
 export function smallIconButtonChromeFrameSize(compact = false): number {
-  return compact ? COMPACT_SMALL_ICON_BUTTON_SIZE : SMALL_ICON_BUTTON_SIZE;
+  return ICON_BUTTON_SIZES.small[controlSizingForLayout(compact)];
 }
 
 const styles = StyleSheet.create((theme) => ({
   large: {
-    width: {
-      xs: COMPACT_LARGE_ICON_BUTTON_SIZE,
-      md: HEADER_CONTROL_HEIGHT,
-    },
-    height: {
-      xs: COMPACT_LARGE_ICON_BUTTON_SIZE,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    width: bySizing(ICON_BUTTON_SIZES.large),
+    height: bySizing(ICON_BUTTON_SIZES.large),
     padding: 0,
     borderRadius: theme.borderRadius.md,
     alignItems: "center",
@@ -119,8 +119,8 @@ const styles = StyleSheet.create((theme) => ({
     outlineColor: "transparent",
   },
   small: {
-    width: SMALL_ICON_BUTTON_SIZE,
-    height: SMALL_ICON_BUTTON_SIZE,
+    width: ICON_BUTTON_SIZES.small.pointer,
+    height: ICON_BUTTON_SIZES.small.pointer,
     padding: 0,
     borderRadius: theme.borderRadius.md,
     alignItems: "center",
@@ -129,9 +129,9 @@ const styles = StyleSheet.create((theme) => ({
     outlineWidth: 0,
     outlineColor: "transparent",
   },
-  smallCompact: {
-    width: COMPACT_SMALL_ICON_BUTTON_SIZE,
-    height: COMPACT_SMALL_ICON_BUTTON_SIZE,
+  smallTouch: {
+    width: ICON_BUTTON_SIZES.small.touch,
+    height: ICON_BUTTON_SIZES.small.touch,
     padding: 0,
     borderRadius: theme.borderRadius.md,
     alignItems: "center",
diff --git a/packages/app/src/components/ui/menu/menu-geometry.ts b/packages/app/src/components/ui/menu/menu-geometry.ts
index 089f4afa67..b0b53e697e 100644
--- a/packages/app/src/components/ui/menu/menu-geometry.ts
+++ b/packages/app/src/components/ui/menu/menu-geometry.ts
@@ -1,2 +1,5 @@
 /** Shared geometry for menu rows and controls that align with them. */
-export const MENU_ITEM_HEIGHT = { xs: 40, md: 28 } as const;
+import { density } from "@/styles/density";
+
+/** A menu row is a tight row: touch-sized wherever controls are (see `resolveControlSizing`). */
+export const MENU_ITEM_HEIGHT = density.tightRowHeight;
diff --git a/packages/app/src/composer/agent-controls/control.tsx b/packages/app/src/composer/agent-controls/control.tsx
index 64b8b39100..a858c64f71 100644
--- a/packages/app/src/composer/agent-controls/control.tsx
+++ b/packages/app/src/composer/agent-controls/control.tsx
@@ -2,6 +2,7 @@ import { forwardRef, useCallback, type ComponentProps } from "react";
 import { Text, View, type PressableStateCallbackType } from "react-native";
 import { StyleSheet } from "react-native-unistyles";
 import { ComboboxTrigger } from "@/components/ui/combobox-trigger";
+import { TOOLBAR_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 import { useComposerControlLayout } from "@/composer/agent-controls/layout-context";
 import { ComposerToolbarGlyph } from "@/composer/agent-controls/glyph";
 import type { AgentControlIcon } from "@/agent-controls/icons";
@@ -96,7 +97,7 @@ export const AgentControlTrigger = forwardRef<View, AgentControlTriggerProps>(
 
 const styles = StyleSheet.create((theme) => ({
   toolbarControl: {
-    height: 28,
+    height: TOOLBAR_CONTROL_HEIGHT,
     minWidth: 0,
     flexShrink: 1,
     flexDirection: "row",
@@ -107,7 +108,7 @@ const styles = StyleSheet.create((theme) => ({
     backgroundColor: "transparent",
   },
   toolbarIconOnly: {
-    width: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
     flexShrink: 0,
     paddingHorizontal: 0,
     justifyContent: "center",
diff --git a/packages/app/src/composer/agent-controls/glyph.tsx b/packages/app/src/composer/agent-controls/glyph.tsx
index 73b2a220c1..f7d68d38c0 100644
--- a/packages/app/src/composer/agent-controls/glyph.tsx
+++ b/packages/app/src/composer/agent-controls/glyph.tsx
@@ -4,7 +4,7 @@ import { StyleSheet, View } from "react-native";
 export function ComposerToolbarGlyph({ children, size }: { children: ReactNode; size: number }) {
   return (
     <View
-      style={size >= 20 ? styles.native : styles.web}
+      style={size >= 20 ? styles.touch : styles.pointer}
       accessibilityElementsHidden
       importantForAccessibility="no-hide-descendants"
       pointerEvents="none"
@@ -15,14 +15,14 @@ export function ComposerToolbarGlyph({ children, size }: { children: ReactNode;
 }
 
 const styles = StyleSheet.create({
-  web: {
+  pointer: {
     width: 16,
     height: 16,
     flexShrink: 0,
     alignItems: "center",
     justifyContent: "center",
   },
-  native: {
+  touch: {
     width: 20,
     height: 20,
     flexShrink: 0,
diff --git a/packages/app/src/composer/agent-controls/index.tsx b/packages/app/src/composer/agent-controls/index.tsx
index 72795289cf..63111538e3 100644
--- a/packages/app/src/composer/agent-controls/index.tsx
+++ b/packages/app/src/composer/agent-controls/index.tsx
@@ -61,6 +61,8 @@ import {
   resolveAgentModelSelection,
 } from "@/composer/agent-controls/utils";
 import { useIsCompactFormFactor } from "@/constants/layout";
+import { controlSizingForLayout, TOOLBAR_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
+import { DensityIcon } from "@/components/ui/density-icon";
 import { readMeasuredWidth } from "@/hooks/use-container-width";
 import { useToast } from "@/contexts/toast-context";
 import { toErrorMessage } from "@/utils/error-messages";
@@ -70,11 +72,10 @@ import {
   type AgentControlCommandCenterSource,
 } from "@/command-center/agent-control-registration";
 import { useComposerKeyboardScope } from "@/composer/keyboard-scope";
-import { isNative } from "@/constants/platform";
 import {
+  composerToolbarGeometry,
   resolveComposerControlDensity,
   resolveComposerControlPresentation,
-  resolveComposerToolbarGlyphSize,
   type ComposerControlDensity,
   type ComposerControlPresentation,
 } from "@/composer/agent-controls/layout";
@@ -460,6 +461,10 @@ function buildAgentProviderModels(
   return map;
 }
 
+function densityFolds(density: ComposerControlDensity): boolean {
+  return resolveComposerControlPresentation(density).foldControls;
+}
+
 function buildOpenChangeHandler(
   selector: AgentControlSelector,
   setOpenSelector: (next: AgentControlSelector | null) => void,
@@ -503,14 +508,20 @@ function ControlledAgentControls({
   modelSelectorServerId = null,
   isCompactLayout,
 }: ControlledAgentControlsProps) {
-  const { theme } = useUnistyles();
   const { t } = useTranslation();
   const isCompactFormFactor = useIsCompactFormFactor();
   const isCompact = isCompactLayout ?? isCompactFormFactor;
+  // Control sizes follow the window layout, as the toolbar's stylesheet does. A narrow pane in a
+  // wide window (`isCompactLayout`) changes which labels show, never how large a control is.
+  const toolbarSizing = controlSizingForLayout(isCompactFormFactor);
+  const toolbarGeometry = useMemo(() => composerToolbarGeometry(toolbarSizing), [toolbarSizing]);
   const { fontScale } = useWindowDimensions();
   const [activeSheet, setActiveSheet] = useState<ActiveSheet>(null);
   const [openSelector, setOpenSelector] = useState<AgentControlSelector | null>(null);
-  const initialDensity: ComposerControlDensity = isCompact ? "tight" : "full";
+  // A compact composer always folds its controls into the model sheet; the width budget only
+  // decides whether the model keeps its label.
+  const minimumDensity: ComposerControlDensity = isCompact ? "compact" : "full";
+  const initialDensity = minimumDensity;
   const [density, setDensity] = useState<ComposerControlDensity>(initialDensity);
   const densityRef = useRef<ComposerControlDensity>(initialDensity);
   const availableWidthRef = useRef(0);
@@ -574,10 +585,10 @@ function ControlledAgentControls({
   const presentation = useMemo(() => resolveComposerControlPresentation(density), [density]);
   const layoutContextValue = useMemo(
     () => ({
-      glyphSize: resolveComposerToolbarGlyphSize(isNative ? "native" : "web"),
+      glyphSize: toolbarGeometry.glyphSize,
       presentation,
     }),
-    [presentation],
+    [presentation, toolbarGeometry],
   );
 
   const updateDensityForWidth = useCallback(
@@ -586,12 +597,20 @@ function ControlledAgentControls({
         availableWidth,
         currentDensity: densityRef.current,
         controls: controlPresence,
+        geometry: toolbarGeometry,
+        minimumDensity,
       });
       if (nextDensity === densityRef.current) return;
+      // Folding swaps the toolbar controls for the model sheet and back, so whatever menu or
+      // sheet was open belonged to controls that are gone.
+      if (densityFolds(nextDensity) !== densityFolds(densityRef.current)) {
+        setOpenSelector(null);
+        setActiveSheet(null);
+      }
       densityRef.current = nextDensity;
       setDensity(nextDensity);
     },
-    [controlPresence],
+    [controlPresence, minimumDensity, toolbarGeometry],
   );
 
   const handleLayout = useCallback(
@@ -633,10 +652,9 @@ function ControlledAgentControls({
         selected={args.selected}
         active={args.active}
         onPress={args.onPress}
-        iconColor={theme.colors.foreground}
       />
     ),
-    [theme.colors.foreground],
+    [],
   );
 
   const handleOpenChange = useCallback(
@@ -702,8 +720,8 @@ function ControlledAgentControls({
 
   const handleCloseSheet = useCallback(() => {
     setActiveSheet(null);
-    if (!isCompact) onDropdownClose?.();
-  }, [isCompact, onDropdownClose]);
+    if (!presentation.foldControls) onDropdownClose?.();
+  }, [onDropdownClose, presentation.foldControls]);
 
   const handleSelectThinkingAndClose = useCallback(
     (thinkingOptionId: string) => {
@@ -734,7 +752,7 @@ function ControlledAgentControls({
   return (
     <ComposerControlLayoutProvider value={layoutContextValue}>
       <View style={styles.container} onLayout={handleLayout}>
-        {!isCompact ? (
+        {!presentation.foldControls ? (
           <DesktopAgentControlsContent
             provider={provider}
             providerOptions={providerOptions}
@@ -821,6 +839,7 @@ function ControlledAgentControls({
             renderThinkingOption={renderThinkingOption}
             modeControl={modeControl}
             glyphSize={layoutContextValue.glyphSize}
+            showLabels={presentation.showModelLabel}
             modelSelectorServerId={modelSelectorServerId}
             canSwitchProvider={Boolean(onSelectProviderAndModel)}
           />
@@ -1144,6 +1163,7 @@ interface SheetAgentControlsContentProps {
   }) => ReactElement;
   modeControl?: AgentModeControlValue | null;
   glyphSize: number;
+  showLabels: boolean;
   modelSelectorServerId: string | null;
   canSwitchProvider: boolean;
 }
@@ -1183,6 +1203,7 @@ function SheetAgentControlsContent(props: SheetAgentControlsContentProps) {
     renderThinkingOption,
     modeControl,
     glyphSize,
+    showLabels,
     modelSelectorServerId,
     canSwitchProvider,
   } = props;
@@ -1271,6 +1292,7 @@ function SheetAgentControlsContent(props: SheetAgentControlsContentProps) {
       isRetryingProvider={isRetryingModelProvider}
       serverId={modelSelectorServerId}
       glyphSize={glyphSize}
+      showLabels={showLabels}
       canSwitchProvider={canSwitchProvider}
     >
       {sheetControls}
@@ -1529,15 +1551,16 @@ function ThinkingComboboxOption({
   selected,
   active,
   onPress,
-  iconColor,
 }: {
   option: ComboboxOption;
   selected: boolean;
   active: boolean;
   onPress: () => void;
-  iconColor: string;
 }) {
-  const leadingSlot = useMemo(() => <ThinkingIcon size={16} color={iconColor} />, [iconColor]);
+  const leadingSlot = useMemo(
+    () => <DensityIcon icon={ThinkingIcon} size="md" color="foreground" />,
+    [],
+  );
   return (
     <ComboboxItem
       label={option.label}
@@ -1953,7 +1976,7 @@ const styles = StyleSheet.create((theme) => ({
     overflow: "hidden",
   },
   modeBadge: {
-    height: 28,
+    height: TOOLBAR_CONTROL_HEIGHT,
     flexDirection: "row",
     alignItems: "center",
     backgroundColor: "transparent",
@@ -1971,8 +1994,8 @@ const styles = StyleSheet.create((theme) => ({
     flexShrink: 0,
   },
   modeIconBadge: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     alignItems: "center",
     justifyContent: "center",
     paddingHorizontal: 0,
diff --git a/packages/app/src/composer/agent-controls/layout-context.tsx b/packages/app/src/composer/agent-controls/layout-context.tsx
index edf8fec7aa..75b4abac80 100644
--- a/packages/app/src/composer/agent-controls/layout-context.tsx
+++ b/packages/app/src/composer/agent-controls/layout-context.tsx
@@ -1,5 +1,8 @@
 import { createContext, useContext, type ReactNode } from "react";
-import type { ComposerControlPresentation } from "@/composer/agent-controls/layout";
+import {
+  resolveComposerControlPresentation,
+  type ComposerControlPresentation,
+} from "@/composer/agent-controls/layout";
 
 interface ComposerControlLayoutValue {
   glyphSize: number;
@@ -8,12 +11,7 @@ interface ComposerControlLayoutValue {
 
 const DEFAULT_LAYOUT: ComposerControlLayoutValue = {
   glyphSize: 16,
-  presentation: {
-    showCarets: true,
-    showThinkingLabel: true,
-    showModeLabel: true,
-    aggregateFeatures: false,
-  },
+  presentation: resolveComposerControlPresentation("full"),
 };
 
 const ComposerControlLayoutContext = createContext(DEFAULT_LAYOUT);
diff --git a/packages/app/src/composer/agent-controls/layout.test.ts b/packages/app/src/composer/agent-controls/layout.test.ts
index 2e52972b1c..2135068bdc 100644
--- a/packages/app/src/composer/agent-controls/layout.test.ts
+++ b/packages/app/src/composer/agent-controls/layout.test.ts
@@ -1,30 +1,42 @@
 import { describe, expect, it } from "vitest";
 import {
-  COMPOSER_TOOLBAR_GEOMETRY,
+  composerToolbarGeometry,
   resolveComposerControlDensity,
   resolveComposerControlPresentation,
-  resolveComposerToolbarGlyphSize,
 } from "./layout";
 
+const POINTER = composerToolbarGeometry("pointer");
+const TOUCH = composerToolbarGeometry("touch");
+
 describe("composer control layout", () => {
-  it("removes labels in priority order as the toolbar narrows", () => {
+  it("removes labels, then folds controls, then drops the model label as the toolbar narrows", () => {
     expect(resolveComposerControlPresentation("full")).toEqual({
       showCarets: true,
       showThinkingLabel: true,
       showModeLabel: true,
       aggregateFeatures: false,
+      foldControls: false,
+      showModelLabel: true,
     });
-    expect(resolveComposerControlPresentation("condensed")).toEqual({
+    expect(resolveComposerControlPresentation("condensed")).toMatchObject({
       showCarets: false,
       showThinkingLabel: false,
       showModeLabel: true,
       aggregateFeatures: true,
+      foldControls: false,
     });
-    expect(resolveComposerControlPresentation("tight")).toEqual({
-      showCarets: false,
-      showThinkingLabel: false,
+    expect(resolveComposerControlPresentation("tight")).toMatchObject({
       showModeLabel: false,
-      aggregateFeatures: true,
+      foldControls: false,
+      showModelLabel: true,
+    });
+    expect(resolveComposerControlPresentation("compact")).toMatchObject({
+      foldControls: true,
+      showModelLabel: true,
+    });
+    expect(resolveComposerControlPresentation("iconOnly")).toMatchObject({
+      foldControls: true,
+      showModelLabel: false,
     });
   });
 
@@ -41,6 +53,7 @@ describe("composer control layout", () => {
       resolveComposerControlDensity({
         availableWidth: 420,
         currentDensity: "full",
+        geometry: POINTER,
         controls,
       }),
     ).toBe("full");
@@ -48,6 +61,7 @@ describe("composer control layout", () => {
       resolveComposerControlDensity({
         availableWidth: 380,
         currentDensity: "full",
+        geometry: POINTER,
         controls,
       }),
     ).toBe("condensed");
@@ -55,6 +69,7 @@ describe("composer control layout", () => {
       resolveComposerControlDensity({
         availableWidth: 290,
         currentDensity: "condensed",
+        geometry: POINTER,
         controls,
       }),
     ).toBe("condensed");
@@ -62,6 +77,7 @@ describe("composer control layout", () => {
       resolveComposerControlDensity({
         availableWidth: 280,
         currentDensity: "condensed",
+        geometry: POINTER,
         controls,
       }),
     ).toBe("tight");
@@ -69,6 +85,7 @@ describe("composer control layout", () => {
       resolveComposerControlDensity({
         availableWidth: 300,
         currentDensity: "tight",
+        geometry: POINTER,
         controls,
       }),
     ).toBe("tight");
@@ -76,6 +93,7 @@ describe("composer control layout", () => {
       resolveComposerControlDensity({
         availableWidth: 312,
         currentDensity: "tight",
+        geometry: POINTER,
         controls,
       }),
     ).toBe("condensed");
@@ -85,6 +103,7 @@ describe("composer control layout", () => {
     const base = {
       availableWidth: 430,
       currentDensity: "condensed" as const,
+      geometry: POINTER,
     };
 
     expect(
@@ -129,6 +148,7 @@ describe("composer control layout", () => {
     const base = {
       availableWidth: 430,
       currentDensity: "full" as const,
+      geometry: POINTER,
       controls: {
         hasModel: true,
         hasThinking: true,
@@ -154,15 +174,97 @@ describe("composer control layout", () => {
     ).toBe("condensed");
   });
 
-  it("gives every toolbar control one shell and one platform glyph envelope", () => {
-    expect(COMPOSER_TOOLBAR_GEOMETRY).toEqual({
+  it("gives every toolbar control one shell and one glyph per control sizing", () => {
+    expect(POINTER).toEqual({
       controlSize: 28,
+      glyphSize: 16,
       controlGap: 4,
       iconLabelGap: 4,
       labelPadding: 8,
       caretSize: 14,
     });
-    expect(resolveComposerToolbarGlyphSize("web")).toBe(16);
-    expect(resolveComposerToolbarGlyphSize("native")).toBe(20);
+    expect(TOUCH).toMatchObject({ controlSize: 44, glyphSize: 20 });
+  });
+
+  it("budgets touch-sized controls, so a touch toolbar condenses at a width a pointer one fits", () => {
+    const input = {
+      availableWidth: 420,
+      currentDensity: "full" as const,
+      controls: {
+        hasModel: true,
+        hasThinking: true,
+        hasMode: true,
+        features: [{ type: "toggle" as const }],
+        fontScale: 1,
+      },
+    };
+
+    expect(resolveComposerControlDensity({ ...input, geometry: POINTER })).toBe("full");
+    expect(resolveComposerControlDensity({ ...input, geometry: TOUCH })).toBe("condensed");
+  });
+
+  describe("touch toolbar on an iPad in portrait, sidebar docked", () => {
+    // Codex: model, thinking, mode and two toggle features. The measured toolbar is 272 wide
+    // with an empty draft and 224 once an attachment brings in the send button.
+    const controls = {
+      hasModel: true,
+      hasThinking: true,
+      hasMode: true,
+      features: [{ type: "toggle" as const }, { type: "toggle" as const }],
+      fontScale: 1,
+    };
+
+    it("keeps the model family label with icon-only controls on an empty draft", () => {
+      expect(
+        resolveComposerControlDensity({
+          availableWidth: 272,
+          currentDensity: "full",
+          geometry: TOUCH,
+          controls,
+        }),
+      ).toBe("tight");
+    });
+
+    it("folds thinking, mode and features into the model control once an attachment narrows it", () => {
+      expect(
+        resolveComposerControlDensity({
+          availableWidth: 224,
+          currentDensity: "tight",
+          geometry: TOUCH,
+          controls,
+        }),
+      ).toBe("compact");
+    });
+
+    it("drops the model label only after the controls are folded", () => {
+      expect(
+        resolveComposerControlDensity({
+          availableWidth: 120,
+          currentDensity: "compact",
+          geometry: TOUCH,
+          controls,
+        }),
+      ).toBe("iconOnly");
+    });
+  });
+
+  it("starts a compact composer at the folded toolbar however wide it is", () => {
+    const input = {
+      currentDensity: "compact" as const,
+      geometry: TOUCH,
+      minimumDensity: "compact" as const,
+      controls: {
+        hasModel: true,
+        hasThinking: true,
+        hasMode: true,
+        features: [],
+        fontScale: 1,
+      },
+    };
+
+    expect(resolveComposerControlDensity({ ...input, availableWidth: 600 })).toBe("compact");
+    // The iPhone toolbar with an attachment: "GPT-6…" beside "Medium" still fits.
+    expect(resolveComposerControlDensity({ ...input, availableWidth: 159 })).toBe("compact");
+    expect(resolveComposerControlDensity({ ...input, availableWidth: 120 })).toBe("iconOnly");
   });
 });
diff --git a/packages/app/src/composer/agent-controls/layout.ts b/packages/app/src/composer/agent-controls/layout.ts
index 6f7c78cc73..f14950231c 100644
--- a/packages/app/src/composer/agent-controls/layout.ts
+++ b/packages/app/src/composer/agent-controls/layout.ts
@@ -1,4 +1,23 @@
-export type ComposerControlDensity = "full" | "condensed" | "tight";
+import {
+  iconSizeFor,
+  TOOLBAR_CONTROL_SIZES,
+  type ControlSizing,
+} from "@/components/ui/control-geometry";
+
+/**
+ * How much of the toolbar shows, widest first. Each step drops something before the next:
+ * carets and labels, then the mode label, then the thinking, mode and feature controls fold into
+ * the model control's sheet (`compact`, the phone toolbar), then the model's own label.
+ */
+export type ComposerControlDensity = "full" | "condensed" | "tight" | "compact" | "iconOnly";
+
+const DENSITY_LADDER: readonly ComposerControlDensity[] = [
+  "full",
+  "condensed",
+  "tight",
+  "compact",
+  "iconOnly",
+];
 
 export interface ComposerControlPresence {
   hasModel: boolean;
@@ -15,27 +34,46 @@ export interface ComposerControlPresentation {
   showThinkingLabel: boolean;
   showModeLabel: boolean;
   aggregateFeatures: boolean;
+  /** Thinking, mode and features live in the model control's sheet. */
+  foldControls: boolean;
+  showModelLabel: boolean;
 }
 
-export const COMPOSER_TOOLBAR_GEOMETRY = {
-  controlSize: 28,
-  controlGap: 4,
-  iconLabelGap: 4,
-  labelPadding: 8,
-  caretSize: 14,
-} as const;
+export interface ComposerToolbarGeometry {
+  controlSize: number;
+  glyphSize: number;
+  controlGap: number;
+  iconLabelGap: number;
+  labelPadding: number;
+  caretSize: number;
+}
+
+/** The toolbar's measurements under a control sizing; see `resolveControlSizing`. */
+export function composerToolbarGeometry(sizing: ControlSizing): ComposerToolbarGeometry {
+  return {
+    controlSize: TOOLBAR_CONTROL_SIZES[sizing],
+    glyphSize: iconSizeFor("md")[sizing],
+    controlGap: 4,
+    iconLabelGap: 4,
+    labelPadding: 8,
+    caretSize: 14,
+  };
+}
 
 const DENSITY_HYSTERESIS = 12;
+/** The model label's narrowest useful width: enough for the model family, such as "GPT-6…". */
+const MODEL_FAMILY_LABEL_WIDTH = 56;
+/** A thinking label beside the folded model label, such as "Medium". */
+const THINKING_LABEL_WIDTH = 48;
 
 function normalizedFontScale(fontScale: number): number {
   return Number.isFinite(fontScale) ? Math.max(1, fontScale) : 1;
 }
 
-function sumControlWidths(widths: number[]): number {
+function sumControlWidths(widths: number[], geometry: ComposerToolbarGeometry): number {
   if (widths.length === 0) return 0;
   return (
-    widths.reduce((total, width) => total + width, 0) +
-    (widths.length - 1) * COMPOSER_TOOLBAR_GEOMETRY.controlGap
+    widths.reduce((total, width) => total + width, 0) + (widths.length - 1) * geometry.controlGap
   );
 }
 
@@ -43,92 +81,173 @@ function estimateLabelWidth(label: string, fontScale: number): number {
   return Array.from(label).length * 7 * fontScale;
 }
 
+/** A labelled control's fixed chrome: its padding, its glyph, and the gap to its label. */
+function labelledChrome(geometry: ComposerToolbarGeometry): number {
+  return geometry.labelPadding * 2 + geometry.glyphSize + geometry.iconLabelGap;
+}
+
 function resolveFeatureControlWidth(
   feature: ComposerFeatureControlPresence,
   fontScale: number,
+  geometry: ComposerToolbarGeometry,
 ): number {
-  if (feature.type === "toggle") return COMPOSER_TOOLBAR_GEOMETRY.controlSize;
+  if (feature.type === "toggle") return geometry.controlSize;
   return (
-    COMPOSER_TOOLBAR_GEOMETRY.controlSize +
-    COMPOSER_TOOLBAR_GEOMETRY.iconLabelGap +
-    COMPOSER_TOOLBAR_GEOMETRY.labelPadding * 2 +
+    geometry.controlSize +
+    geometry.iconLabelGap +
+    geometry.labelPadding * 2 +
     estimateLabelWidth(feature.label, fontScale)
   );
 }
 
-function resolveCondensedFloor(controls: ComposerControlPresence): number {
+function resolveCondensedFloor(
+  controls: ComposerControlPresence,
+  geometry: ComposerToolbarGeometry,
+): number {
   const fontScale = normalizedFontScale(controls.fontScale);
+  const chrome = labelledChrome(geometry);
   const widths: number[] = [];
-  if (controls.hasModel) widths.push(36 + 60 * fontScale);
-  if (controls.hasThinking) widths.push(COMPOSER_TOOLBAR_GEOMETRY.controlSize);
-  if (controls.hasMode) widths.push(36 + 96 * fontScale);
-  if (controls.features.length > 0) widths.push(COMPOSER_TOOLBAR_GEOMETRY.controlSize);
-  return sumControlWidths(widths);
+  if (controls.hasModel) widths.push(chrome + 60 * fontScale);
+  if (controls.hasThinking) widths.push(geometry.controlSize);
+  if (controls.hasMode) widths.push(chrome + 96 * fontScale);
+  if (controls.features.length > 0) widths.push(geometry.controlSize);
+  return sumControlWidths(widths, geometry);
 }
 
-function resolveFullFloor(controls: ComposerControlPresence): number {
+function resolveFullFloor(
+  controls: ComposerControlPresence,
+  geometry: ComposerToolbarGeometry,
+): number {
   const fontScale = normalizedFontScale(controls.fontScale);
+  const chrome = labelledChrome(geometry);
+  const caret = geometry.caretSize;
   const widths: number[] = [];
-  if (controls.hasModel) widths.push(50 + 70 * fontScale);
-  if (controls.hasThinking) widths.push(54 + 48 * fontScale);
-  if (controls.hasMode) widths.push(54 + 96 * fontScale);
+  if (controls.hasModel) widths.push(chrome + caret + 70 * fontScale);
+  if (controls.hasThinking) widths.push(chrome + geometry.iconLabelGap + caret + 48 * fontScale);
+  if (controls.hasMode) widths.push(chrome + geometry.iconLabelGap + caret + 96 * fontScale);
   for (const feature of controls.features) {
-    widths.push(resolveFeatureControlWidth(feature, fontScale));
+    widths.push(resolveFeatureControlWidth(feature, fontScale, geometry));
   }
-  return sumControlWidths(widths);
+  return sumControlWidths(widths, geometry);
 }
 
+/** Model at its family label, with thinking, mode and features as icon-only squares. */
+function resolveTightFloor(
+  controls: ComposerControlPresence,
+  geometry: ComposerToolbarGeometry,
+): number {
+  const fontScale = normalizedFontScale(controls.fontScale);
+  const widths: number[] = [];
+  if (controls.hasModel) {
+    widths.push(labelledChrome(geometry) + MODEL_FAMILY_LABEL_WIDTH * fontScale);
+  }
+  if (controls.hasThinking) widths.push(geometry.controlSize);
+  if (controls.hasMode) widths.push(geometry.controlSize);
+  if (controls.features.length > 0) widths.push(geometry.controlSize);
+  return sumControlWidths(widths, geometry);
+}
+
+/** One model control carrying the model family label and the thinking label. */
+function resolveCompactFloor(
+  controls: ComposerControlPresence,
+  geometry: ComposerToolbarGeometry,
+): number {
+  const fontScale = normalizedFontScale(controls.fontScale);
+  const thinkingLabel = controls.hasThinking
+    ? geometry.iconLabelGap + THINKING_LABEL_WIDTH * fontScale
+    : 0;
+  return labelledChrome(geometry) + MODEL_FAMILY_LABEL_WIDTH * fontScale + thinkingLabel;
+}
+
+function resolveDensityFloor(
+  density: ComposerControlDensity,
+  controls: ComposerControlPresence,
+  geometry: ComposerToolbarGeometry,
+): number {
+  switch (density) {
+    case "full":
+      return resolveFullFloor(controls, geometry);
+    case "condensed":
+      return resolveCondensedFloor(controls, geometry);
+    case "tight":
+      return resolveTightFloor(controls, geometry);
+    case "compact":
+      return resolveCompactFloor(controls, geometry);
+    case "iconOnly":
+      return 0;
+  }
+}
+
+/**
+ * The widest density whose floor fits `availableWidth`. Widening past the current density needs
+ * the floor plus the hysteresis and keeping it tolerates the floor minus it, so a width near a
+ * floor does not flip back and forth. `minimumDensity` is the widest density allowed.
+ */
 export function resolveComposerControlDensity(input: {
   availableWidth: number;
   currentDensity: ComposerControlDensity;
   controls: ComposerControlPresence;
+  geometry: ComposerToolbarGeometry;
+  minimumDensity?: ComposerControlDensity;
 }): ComposerControlDensity {
-  const fullFloor = resolveFullFloor(input.controls);
-  const condensedFloor = resolveCondensedFloor(input.controls);
-
-  if (input.currentDensity === "full") {
-    if (input.availableWidth >= fullFloor - DENSITY_HYSTERESIS) return "full";
-    return input.availableWidth >= condensedFloor ? "condensed" : "tight";
+  const current = DENSITY_LADDER.indexOf(input.currentDensity);
+  const first = DENSITY_LADDER.indexOf(input.minimumDensity ?? "full");
+  for (let step = first; step < DENSITY_LADDER.length; step += 1) {
+    const density = DENSITY_LADDER[step];
+    const floor = resolveDensityFloor(density, input.controls, input.geometry);
+    let required = floor;
+    if (step < current) required = floor + DENSITY_HYSTERESIS;
+    if (step === current) required = floor - DENSITY_HYSTERESIS;
+    if (input.availableWidth >= required) return density;
   }
-
-  if (input.currentDensity === "condensed") {
-    if (input.availableWidth >= fullFloor + DENSITY_HYSTERESIS) return "full";
-    if (input.availableWidth < condensedFloor - DENSITY_HYSTERESIS) return "tight";
-    return "condensed";
-  }
-
-  if (input.availableWidth >= fullFloor + DENSITY_HYSTERESIS) return "full";
-  if (input.availableWidth >= condensedFloor + DENSITY_HYSTERESIS) return "condensed";
-  return "tight";
+  return "iconOnly";
 }
 
-export function resolveComposerControlPresentation(
-  density: ComposerControlDensity,
-): ComposerControlPresentation {
-  if (density === "full") {
-    return {
-      showCarets: true,
-      showThinkingLabel: true,
-      showModeLabel: true,
-      aggregateFeatures: false,
-    };
-  }
-  if (density === "condensed") {
-    return {
-      showCarets: false,
-      showThinkingLabel: false,
-      showModeLabel: true,
-      aggregateFeatures: true,
-    };
-  }
-  return {
+const PRESENTATIONS: Record<ComposerControlDensity, ComposerControlPresentation> = {
+  full: {
+    showCarets: true,
+    showThinkingLabel: true,
+    showModeLabel: true,
+    aggregateFeatures: false,
+    foldControls: false,
+    showModelLabel: true,
+  },
+  condensed: {
+    showCarets: false,
+    showThinkingLabel: false,
+    showModeLabel: true,
+    aggregateFeatures: true,
+    foldControls: false,
+    showModelLabel: true,
+  },
+  tight: {
     showCarets: false,
     showThinkingLabel: false,
     showModeLabel: false,
     aggregateFeatures: true,
-  };
-}
+    foldControls: false,
+    showModelLabel: true,
+  },
+  compact: {
+    showCarets: false,
+    showThinkingLabel: true,
+    showModeLabel: false,
+    aggregateFeatures: true,
+    foldControls: true,
+    showModelLabel: true,
+  },
+  iconOnly: {
+    showCarets: false,
+    showThinkingLabel: false,
+    showModeLabel: false,
+    aggregateFeatures: true,
+    foldControls: true,
+    showModelLabel: false,
+  },
+};
 
-export function resolveComposerToolbarGlyphSize(platform: "web" | "native"): number {
-  return platform === "native" ? 20 : 16;
+export function resolveComposerControlPresentation(
+  density: ComposerControlDensity,
+): ComposerControlPresentation {
+  return PRESENTATIONS[density];
 }
diff --git a/packages/app/src/composer/agent-controls/mode-control.tsx b/packages/app/src/composer/agent-controls/mode-control.tsx
index 59fb515ce5..25352d8a9d 100644
--- a/packages/app/src/composer/agent-controls/mode-control.tsx
+++ b/packages/app/src/composer/agent-controls/mode-control.tsx
@@ -27,6 +27,7 @@ import { showProviderNoticeToast } from "@/utils/provider-notice-toast";
 import type { AgentMode } from "@getpaseo/protocol/agent-types";
 import type { AgentProviderDefinition } from "@getpaseo/protocol/provider-manifest";
 import { getAgentModeIcon, getAgentModeOptionIcon } from "@/agent-controls/icons";
+import { DensityIcon } from "@/components/ui/density-icon";
 interface ModeComboboxOptionProps {
   option: ComboboxOption;
   selected: boolean;
@@ -34,7 +35,6 @@ interface ModeComboboxOptionProps {
   onPress: () => void;
   provider: string;
   providerDefinitions: AgentProviderDefinition[];
-  iconColor: string;
 }
 
 function ModeComboboxOption({
@@ -44,12 +44,12 @@ function ModeComboboxOption({
   onPress,
   provider,
   providerDefinitions,
-  iconColor,
 }: ModeComboboxOptionProps) {
   const IconComponent = getAgentModeOptionIcon(provider, option.id, providerDefinitions);
   const leadingSlot = useMemo(
-    () => (IconComponent ? <IconComponent size={16} color={iconColor} /> : null),
-    [IconComponent, iconColor],
+    () =>
+      IconComponent ? <DensityIcon icon={IconComponent} size="md" color="foreground" /> : null,
+    [IconComponent],
   );
   return (
     <ComboboxItem
@@ -171,10 +171,9 @@ export function AgentModeControl({
         onPress={args.onPress}
         provider={provider}
         providerDefinitions={providerDefinitions}
-        iconColor={theme.colors.foreground}
       />
     ),
-    [provider, providerDefinitions, theme.colors.foreground],
+    [provider, providerDefinitions],
   );
 
   const sheetHeader = useMemo<SheetHeader>(
diff --git a/packages/app/src/composer/agent-controls/model-sheet.tsx b/packages/app/src/composer/agent-controls/model-sheet.tsx
index 6929b447ea..2eccda373d 100644
--- a/packages/app/src/composer/agent-controls/model-sheet.tsx
+++ b/packages/app/src/composer/agent-controls/model-sheet.tsx
@@ -15,6 +15,7 @@ import { resolveModelSheetOpening } from "@/composer/agent-controls/model-sheet-
 import type { ProviderSelectorProvider } from "@/provider-selection/provider-selection";
 import { useIsCompactFormFactor } from "@/constants/layout";
 import { isNative, isWeb } from "@/constants/platform";
+import { TOOLBAR_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 
 const SNAP_POINTS = ["80%", "90%"];
 const MODEL_LIST_TOP_INSET = 4;
@@ -42,6 +43,8 @@ interface CompactModelSheetProps {
   disabled?: boolean;
   serverId?: string | null;
   glyphSize: number;
+  /** False when the toolbar is too narrow for labels: the trigger shows the provider glyph only. */
+  showLabels: boolean;
   canSwitchProvider: boolean;
   children: ReactNode;
 }
@@ -94,6 +97,7 @@ export function CompactModelSheet({
   disabled = false,
   serverId = null,
   glyphSize,
+  showLabels,
   canSwitchProvider,
   children,
 }: CompactModelSheetProps) {
@@ -229,14 +233,16 @@ export function CompactModelSheet({
     open();
   }, [close, isOpen, open]);
 
+  const iconOnly = !showLabels && hasSelectedProvider;
   const triggerStyle = useCallback(
     ({ hovered, pressed }: PressableStateCallbackType) => [
       styles.trigger,
+      iconOnly && styles.triggerIconOnly,
       hovered && styles.triggerHovered,
       (pressed || isOpen) && styles.triggerPressed,
       disabled && styles.triggerDisabled,
     ],
-    [disabled, isOpen],
+    [disabled, iconOnly, isOpen],
   );
   const mobileRootContent = useMemo(
     () => (
@@ -280,16 +286,18 @@ export function CompactModelSheet({
             <ModelIcon size={glyphSize} color={styles.providerIcon.color} />
           </ComposerToolbarGlyph>
         ) : null}
-        <View style={styles.triggerLabels}>
-          <Text style={styles.triggerText} numberOfLines={1}>
-            {shortModelLabel(rootBrowser.triggerLabel)}
-          </Text>
-          {thinkingLabel ? (
-            <Text style={styles.triggerThinking} numberOfLines={1}>
-              {thinkingLabel}
+        {!iconOnly ? (
+          <View style={styles.triggerLabels}>
+            <Text style={styles.triggerText} numberOfLines={1}>
+              {shortModelLabel(rootBrowser.triggerLabel)}
             </Text>
-          ) : null}
-        </View>
+            {thinkingLabel ? (
+              <Text style={styles.triggerThinking} numberOfLines={1}>
+                {thinkingLabel}
+              </Text>
+            ) : null}
+          </View>
+        ) : null}
       </ComboboxTrigger>
 
       <AdaptiveModalSheet
@@ -374,7 +382,7 @@ export function CompactModelSheet({
 
 const styles = StyleSheet.create((theme) => ({
   trigger: {
-    height: 28,
+    height: TOOLBAR_CONTROL_HEIGHT,
     minWidth: 0,
     flexShrink: 1,
     flexDirection: "row",
@@ -384,6 +392,12 @@ const styles = StyleSheet.create((theme) => ({
     borderRadius: theme.borderRadius["2xl"],
     backgroundColor: "transparent",
   },
+  triggerIconOnly: {
+    width: TOOLBAR_CONTROL_HEIGHT,
+    flexShrink: 0,
+    paddingHorizontal: 0,
+    justifyContent: "center",
+  },
   triggerHovered: {
     backgroundColor: theme.colors.surface2,
   },
diff --git a/packages/app/src/composer/index.tsx b/packages/app/src/composer/index.tsx
index d6b4bae63f..af9a56b826 100644
--- a/packages/app/src/composer/index.tsx
+++ b/packages/app/src/composer/index.tsx
@@ -31,6 +31,11 @@ import {
 import { useTranslation } from "react-i18next";
 import { StyleSheet, withUnistyles } from "react-native-unistyles";
 import { useIsCompactFormFactor } from "@/constants/layout";
+import {
+  controlSizingForLayout,
+  iconSizeFor,
+  TOOLBAR_CONTROL_HEIGHT,
+} from "@/components/ui/control-geometry";
 import { usePanelStore } from "@/stores/panel-store";
 import { useHasFinePointer } from "@/hooks/use-fine-pointer";
 import { useShallow } from "zustand/shallow";
@@ -193,10 +198,6 @@ const EMPTY_ATTACHMENT_SCOPE_KEYS: readonly string[] = [];
 function noop() {}
 const noopCallback = () => {};
 
-function resolveComposerButtonIconSize(): number {
-  return isWeb ? ICON_SIZE.md : ICON_SIZE.lg;
-}
-
 function resolveIsComposerLocked(
   submitBehavior: "clear" | "preserve-and-lock",
   isSubmitLoading: boolean,
@@ -1281,7 +1282,6 @@ function ComposerContentImpl({
 }: ComposerContentProps) {
   const mode = resolveComposerInputMode(inputMode);
   const { t } = useTranslation();
-  const buttonIconSize = resolveComposerButtonIconSize();
   const client = useHostRuntimeClient(serverId);
   const isConnected = useHostRuntimeIsConnected(serverId);
   const agentDirectoryStatus = useHostRuntimeAgentDirectoryStatus(serverId);
@@ -1310,6 +1310,7 @@ function ComposerContentImpl({
 
   const isCompactFormFactor = useIsCompactFormFactor();
   const isCompactLayout = resolveCompactLayout(isCompactLayoutOverride, isCompactFormFactor);
+  const buttonIconSize = iconSizeFor("md")[controlSizingForLayout(isCompactFormFactor)];
   const isDesktopWebBreakpoint = resolveIsDesktopWebBreakpoint(isCompactFormFactor);
   const hasFinePointer = useHasFinePointer();
   const isDesktopLayout = resolveIsDesktopWebBreakpoint(isCompactLayout);
@@ -2081,7 +2082,6 @@ function ComposerContentImpl({
     ],
   );
 
-  const contextWindowMeterGlyphSize = isCompactLayout ? ICON_SIZE.md : buttonIconSize;
   const beforeVoiceContent = useMemo(
     () =>
       hasAgent ? (
@@ -2092,7 +2092,7 @@ function ComposerContentImpl({
             maxTokens={agentState.contextWindowMaxTokens}
             usedTokens={agentState.contextWindowUsedTokens}
             totalCostUsd={agentState.totalCostUsd}
-            glyphSize={contextWindowMeterGlyphSize}
+            glyphSize={buttonIconSize}
           />
         </View>
       ) : null,
@@ -2103,7 +2103,7 @@ function ComposerContentImpl({
       agentState.contextWindowMaxTokens,
       agentState.contextWindowUsedTokens,
       agentState.totalCostUsd,
-      contextWindowMeterGlyphSize,
+      buttonIconSize,
     ],
   );
 
@@ -2598,8 +2598,8 @@ const styles = StyleSheet.create((theme: Theme) => ({
     gap: theme.spacing[3],
   },
   cancelButton: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     borderRadius: theme.borderRadius.full,
     backgroundColor: theme.colors.palette.red[600],
     alignItems: "center",
@@ -2612,15 +2612,15 @@ const styles = StyleSheet.create((theme: Theme) => ({
     gap: theme.spacing[1],
   },
   contextWindowMeterSlot: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     flexShrink: 0,
     alignItems: "center",
     justifyContent: "center",
   },
   realtimeVoiceButton: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     borderRadius: theme.borderRadius.full,
     alignItems: "center",
     justifyContent: "center",
diff --git a/packages/app/src/composer/input/input.tsx b/packages/app/src/composer/input/input.tsx
index 618b923024..311e4dedd4 100644
--- a/packages/app/src/composer/input/input.tsx
+++ b/packages/app/src/composer/input/input.tsx
@@ -27,7 +27,12 @@ import {
 } from "react";
 import { StyleSheet, withUnistyles } from "react-native-unistyles";
 import { useTranslation } from "react-i18next";
-import { ICON_SIZE, type Theme } from "@/styles/theme";
+import type { Theme } from "@/styles/theme";
+import {
+  controlSizingForLayout,
+  iconSizeFor,
+  TOOLBAR_CONTROL_HEIGHT,
+} from "@/components/ui/control-geometry";
 import { ArrowUp, Mic, MicOff, CornerDownLeft, Plus, Square } from "lucide-react-native";
 import * as Haptics from "expo-haptics";
 import { useDictation } from "@/hooks/use-dictation";
@@ -1282,7 +1287,8 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
     const isFullscreen = useComposerFullscreen(editingSession);
     const [renderedLines, setRenderedLines] = useState(1);
     const maxInputHeight = resolveMaxInputHeight(windowHeight, isCompact);
-    const buttonIconSize = isWeb ? ICON_SIZE.md : ICON_SIZE.lg;
+    const controlSizing = controlSizingForLayout(isCompact);
+    const buttonIconSize = iconSizeFor("md")[controlSizing];
     const toast = useToast();
     const voice = useVoiceOptional();
     const voiceMuteToggleKeys = useShortcutKeys("voice-mute-toggle");
@@ -2235,6 +2241,7 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
         />
         <ComposerInputPresentation
           fullscreen={isFullscreen}
+          controlSizing={controlSizing}
           sendIconSize={buttonIconSize}
           surface={textSurface}
           toolbar={toolbar}
@@ -2384,21 +2391,21 @@ const styles = StyleSheet.create((theme: Theme) => ({
     gap: theme.spacing[1],
   },
   attachButton: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     borderRadius: theme.borderRadius.full,
     alignItems: "center",
     justifyContent: "center",
   },
   attachButtonAnchor: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     alignItems: "center",
     justifyContent: "center",
   },
   voiceButton: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     borderRadius: theme.borderRadius.full,
     alignItems: "center",
     justifyContent: "center",
@@ -2407,8 +2414,8 @@ const styles = StyleSheet.create((theme: Theme) => ({
     backgroundColor: theme.colors.destructive,
   },
   sendButton: {
-    width: 28,
-    height: 28,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     borderRadius: theme.borderRadius.full,
     backgroundColor: theme.colors.accent,
     alignItems: "center",
@@ -2417,7 +2424,7 @@ const styles = StyleSheet.create((theme: Theme) => ({
   },
   sendButtonLabeled: {
     width: "auto",
-    minWidth: 28,
+    minWidth: TOOLBAR_CONTROL_HEIGHT,
     paddingHorizontal: theme.spacing[3],
     borderRadius: theme.borderRadius.full,
   },
diff --git a/packages/app/src/composer/input/presentation.tsx b/packages/app/src/composer/input/presentation.tsx
index 23f78c58ee..956dc22597 100644
--- a/packages/app/src/composer/input/presentation.tsx
+++ b/packages/app/src/composer/input/presentation.tsx
@@ -6,14 +6,16 @@ import { Button } from "@/components/ui/button";
 import { ComposerFullscreenBody, ComposerFullscreenFooter } from "@/composer/dock";
 import { useComposerKeyboardScope } from "@/composer/keyboard-scope";
 import { isWeb } from "@/constants/platform";
-import { ICON_SIZE } from "@/styles/theme";
+import {
+  iconSizeFor,
+  TOOLBAR_CONTROL_HEIGHT,
+  TOOLBAR_CONTROL_SIZES,
+  type ControlSizing,
+} from "@/components/ui/control-geometry";
 import { StyleSheet } from "react-native-unistyles";
 import { useComposerFullscreenExit } from "./fullscreen-exit";
 import { resolveGlyphRailOffset } from "./state";
 
-const CONTROL_SIZE = 28;
-const FULLSCREEN_GLYPH_SIZE = ICON_SIZE.md;
-
 function keepEditorFocused(event: import("react-native").PointerEvent) {
   if (isWeb) event.preventDefault();
 }
@@ -27,6 +29,7 @@ function keepEditorFocused(event: import("react-native").PointerEvent) {
  */
 export function ComposerInputPresentation({
   fullscreen,
+  controlSizing,
   sendIconSize,
   surface,
   toolbar,
@@ -42,6 +45,8 @@ export function ComposerInputPresentation({
   overlay,
 }: {
   fullscreen: boolean;
+  /** The sizing the toolbar's stylesheet resolves to; see `resolveControlSizing`. */
+  controlSizing: ControlSizing;
   sendIconSize: number;
   surface: ReactNode;
   toolbar: ReactNode;
@@ -61,18 +66,19 @@ export function ComposerInputPresentation({
   // action (Escape, hardware back) belongs only to the pane the user is in.
   const { isActiveComposer } = useComposerKeyboardScope();
   const exitScopeRef = useComposerFullscreenExit(fullscreen && isActiveComposer, onExit);
+  const glyphSize = iconSizeFor("md")[controlSizing];
   const railOffset = resolveGlyphRailOffset({
-    controlSize: CONTROL_SIZE,
+    controlSize: TOOLBAR_CONTROL_SIZES[controlSizing],
     sendIconSize,
-    glyphIconSize: FULLSCREEN_GLYPH_SIZE,
+    glyphIconSize: glyphSize,
   });
   const maximizeIcon = useCallback(
-    (color: string) => <Maximize2 color={color} size={FULLSCREEN_GLYPH_SIZE} />,
-    [],
+    (color: string) => <Maximize2 color={color} size={glyphSize} />,
+    [glyphSize],
   );
   const minimizeIcon = useCallback(
-    (color: string) => <Minimize2 color={color} size={FULLSCREEN_GLYPH_SIZE} />,
-    [],
+    (color: string) => <Minimize2 color={color} size={glyphSize} />,
+    [glyphSize],
   );
   // The toolbar row bleeds 6px past the input padding; the inline glyph sits on that edge.
   const enterStyle = useMemo(() => [styles.enterButton, { right: -6 + railOffset }], [railOffset]);
@@ -141,8 +147,8 @@ const styles = StyleSheet.create((theme) => ({
   inline: { flexShrink: 1, position: "relative" },
   inlineTextSurface: { flexShrink: 1, position: "relative" },
   iconButton: {
-    width: CONTROL_SIZE,
-    height: CONTROL_SIZE,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     padding: 0,
     borderWidth: 0,
     borderRadius: theme.borderRadius.full,
@@ -150,8 +156,8 @@ const styles = StyleSheet.create((theme) => ({
   enterButton: {
     position: "absolute",
     top: 0,
-    width: CONTROL_SIZE,
-    height: CONTROL_SIZE,
+    width: TOOLBAR_CONTROL_HEIGHT,
+    height: TOOLBAR_CONTROL_HEIGHT,
     padding: 0,
     borderWidth: 0,
     borderRadius: theme.borderRadius.full,
diff --git a/packages/app/src/composer/tracks.tsx b/packages/app/src/composer/tracks.tsx
index a6c0db1098..71ed312739 100644
--- a/packages/app/src/composer/tracks.tsx
+++ b/packages/app/src/composer/tracks.tsx
@@ -13,6 +13,7 @@ import {
   type MenuTriggerState,
 } from "@/components/ui/menu";
 import { StatusRing } from "@/components/status-ring";
+import { bySizing } from "@/components/ui/control-geometry";
 import { STATUS_RING_HALO_INSET } from "@/components/status-ring/geometry";
 import { isWeb } from "@/constants/platform";
 import { getStatusDotColor } from "@/utils/status-dot-color";
@@ -343,16 +344,17 @@ const styles = StyleSheet.create((theme) => {
   // The rail every panel row sits on: inset from the panel edge so the fill is a rounded block
   // inside it, and tall enough that revealing an action button cannot resize the row.
   //
-  // Compact and desktop differ here and only here. A finger needs the taller row a menu row gets
-  // on compact; a pointer does not, and the popover keeps its density.
+  // Touch and pointer sizing differ here and only here. A finger needs the row a menu row gets
+  // on touch (`MENU_ITEM_HEIGHT` is always its touch value at `xs`); a pointer does not, and the
+  // popover keeps its density.
   const trackRow = {
     flexDirection: "row",
     alignItems: "center",
     gap: theme.spacing[2],
-    minHeight: { xs: MENU_ITEM_HEIGHT.xs, md: 32 },
+    minHeight: bySizing({ touch: MENU_ITEM_HEIGHT.xs, pointer: 32 }),
     marginHorizontal: theme.spacing[1],
     paddingHorizontal: theme.spacing[2],
-    paddingVertical: { xs: theme.spacing[2], md: theme.spacing[1] },
+    paddingVertical: bySizing({ touch: theme.spacing[2], pointer: theme.spacing[1] }),
     borderRadius: theme.borderRadius.md,
   } as const;
 
diff --git a/packages/app/src/constants/layout.ts b/packages/app/src/constants/layout.ts
index 739be45ee9..ee30a611ff 100644
--- a/packages/app/src/constants/layout.ts
+++ b/packages/app/src/constants/layout.ts
@@ -1,14 +1,19 @@
 import { useUnistyles } from "react-native-unistyles";
+import { bySizing, TOUCH_TARGET } from "@/components/ui/control-sizing";
 import { isWeb } from "@/constants/platform";
 
 export const FOOTER_HEIGHT = 75;
 
-// Shared header inner height (excluding safe area insets and border)
+// A bar of icon buttons: touch-sized it is one touch target tall, like an iOS navigation bar.
+const BAR_HEIGHT = { touch: TOUCH_TARGET, pointer: 36 };
+
+// Shared header inner height from `md` up (excluding safe area insets and border).
 // Used by both agent header (ScreenHeader) and explorer sidebar header
 // This ensures both headers have the same visual height
-export const HEADER_INNER_HEIGHT = 36;
+export const HEADER_INNER_HEIGHT = bySizing(BAR_HEIGHT).md;
 export const HEADER_INNER_HEIGHT_MOBILE = 56;
-export const WORKSPACE_SECONDARY_HEADER_HEIGHT = 36;
+/** The tab rail and pane toolbars under the header. A breakpoint value for stylesheets. */
+export const WORKSPACE_SECONDARY_HEADER_HEIGHT = bySizing(BAR_HEIGHT);
 export const HEADER_TOP_PADDING_MOBILE = 8;
 
 // Measured composer width; independent of the window's compact/wide breakpoint.
diff --git a/packages/app/src/git/actions-split-button.tsx b/packages/app/src/git/actions-split-button.tsx
index 7bd9aaf055..eb52e5ca53 100644
--- a/packages/app/src/git/actions-split-button.tsx
+++ b/packages/app/src/git/actions-split-button.tsx
@@ -17,7 +17,7 @@ import { inlineUnistylesStyle } from "@/styles/unistyles-inline-style";
 import type { ShortcutKey } from "@/utils/format-shortcut";
 import { actionsWithoutPrimary, type GitAction, type GitActions } from "@/git/policy";
 import { useGitActionRunner } from "@/git/use-actions";
-import { CONTROL_HEIGHTS, HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
+import { HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 
 interface GitActionsSplitButtonProps {
   gitActions: GitActions;
@@ -272,10 +272,7 @@ const styles = StyleSheet.create((theme) => ({
     flexShrink: 0,
   },
   splitButton: {
-    height: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    height: HEADER_CONTROL_HEIGHT,
     flexDirection: "row",
     alignItems: "stretch",
     borderRadius: theme.borderRadius.md,
@@ -296,10 +293,7 @@ const styles = StyleSheet.create((theme) => ({
       xs: 48,
       md: 42,
     },
-    height: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    height: HEADER_CONTROL_HEIGHT,
     flexDirection: "row",
     alignItems: "center",
     justifyContent: "center",
@@ -330,24 +324,15 @@ const styles = StyleSheet.create((theme) => ({
     transform: [{ scale: 0.8 }],
   },
   splitButtonCaret: {
-    width: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    width: HEADER_CONTROL_HEIGHT,
     alignItems: "center",
     justifyContent: "center",
     borderLeftWidth: theme.borderWidth[1],
     borderLeftColor: theme.colors.borderAccent,
   },
   iconButton: {
-    width: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
-    height: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    width: HEADER_CONTROL_HEIGHT,
+    height: HEADER_CONTROL_HEIGHT,
     alignItems: "center",
     justifyContent: "center",
     borderRadius: theme.borderRadius.md,
diff --git a/packages/app/src/git/pull-request-panel/section-kit.tsx b/packages/app/src/git/pull-request-panel/section-kit.tsx
index 3022d93161..b4a9d00a3a 100644
--- a/packages/app/src/git/pull-request-panel/section-kit.tsx
+++ b/packages/app/src/git/pull-request-panel/section-kit.tsx
@@ -2,7 +2,7 @@ import React, { type ReactNode } from "react";
 import { Pressable, Text, View } from "react-native";
 import { StyleSheet, withUnistyles } from "react-native-unistyles";
 import type { CountedCheckPresentation } from "@/git/check-presentation";
-import { CONTROL_HEIGHTS } from "@/components/ui/control-geometry";
+import { CONTROL_HEIGHTS, mapLayout } from "@/components/ui/control-geometry";
 import {
   CheckPresentationIcon,
   getCheckPresentationTone,
@@ -164,10 +164,10 @@ export const sectionKitStyles = StyleSheet.create((theme) => ({
     gap: theme.spacing[2],
     paddingHorizontal: theme.spacing[3],
     // Fixed, not minHeight plus padding. A row's trailing slot holds an sm Button
-    // (28pt), which stacked on the vertical padding and made rows with an
+    // , which stacked on the vertical padding and made rows with an
     // "Add to chat" button taller than rows without one. The row is single-line by
     // construction, so it declares a height the button fits inside instead.
-    height: CONTROL_HEIGHTS.sm + theme.spacing[1],
+    height: mapLayout(CONTROL_HEIGHTS.sm, (height) => height + theme.spacing[1]),
   },
   checkName: {
     fontSize: theme.fontSize.base,
diff --git a/packages/app/src/hooks/use-fine-pointer.ts b/packages/app/src/hooks/use-fine-pointer.ts
index a0bc2489bf..dcd8fe0853 100644
--- a/packages/app/src/hooks/use-fine-pointer.ts
+++ b/packages/app/src/hooks/use-fine-pointer.ts
@@ -18,6 +18,16 @@ export function hasFinePointer(): boolean {
   return getFinePointerQueryList()?.matches ?? false;
 }
 
+/**
+ * True when the device has a touch screen, even while a mouse or keyboard is attached to it:
+ * the primary pointer is coarse, or the screen reports touch points. Always true on native.
+ */
+export function hasTouchScreen(): boolean {
+  if (!isWeb) return true;
+  if (typeof window === "undefined" || typeof window.matchMedia !== "function") return false;
+  return window.matchMedia("(pointer: coarse)").matches || window.navigator.maxTouchPoints > 0;
+}
+
 /**
  * Reactive `hasFinePointer()` — re-renders when the user switches between a
  * mouse and touch (detachable keyboards, tablet mode).
diff --git a/packages/app/src/plugins/buttons/view.tsx b/packages/app/src/plugins/buttons/view.tsx
index 889d71001f..1876fef431 100644
--- a/packages/app/src/plugins/buttons/view.tsx
+++ b/packages/app/src/plugins/buttons/view.tsx
@@ -656,8 +656,8 @@ const styles = StyleSheet.create((theme) => ({
     gap: { xs: theme.spacing[1], md: theme.spacing[2] },
   },
   headerButton: {
-    height: { xs: 32, md: HEADER_CONTROL_HEIGHT },
-    minWidth: { xs: 32, md: HEADER_CONTROL_HEIGHT },
+    height: HEADER_CONTROL_HEIGHT,
+    minWidth: HEADER_CONTROL_HEIGHT,
     paddingHorizontal: theme.spacing[2],
     flexDirection: "row",
     alignItems: "center",
diff --git a/packages/app/src/screens/settings-screen.tsx b/packages/app/src/screens/settings-screen.tsx
index 8bce0c4dd1..9c8b230e4c 100644
--- a/packages/app/src/screens/settings-screen.tsx
+++ b/packages/app/src/screens/settings-screen.tsx
@@ -125,7 +125,7 @@ import {
   SETTINGS_DESKTOP_SIDEBAR_WIDTH,
   useIsCompactFormFactor,
 } from "@/constants/layout";
-import { densityIconBox, densityIconSize } from "@/styles/density";
+import { density, densityIconBox, densityIconSize } from "@/styles/density";
 import { useLocalDaemonServerId } from "@/hooks/use-is-local-daemon";
 import {
   type EnableBuiltInDaemonOption,
@@ -1523,7 +1523,7 @@ const sidebarStyles = StyleSheet.create((theme) => ({
     flexDirection: "row",
     alignItems: "center",
     gap: { xs: theme.spacing[3], md: theme.spacing[2] },
-    minHeight: { xs: 52, md: 28 },
+    minHeight: { xs: 52, md: density.tightRowHeight.md },
     paddingVertical: theme.spacing[1],
     paddingHorizontal: { xs: theme.spacing[4], md: theme.spacing[2] },
     borderRadius: { xs: 0, md: theme.borderRadius.lg },
@@ -1549,7 +1549,7 @@ const sidebarStyles = StyleSheet.create((theme) => ({
     flexDirection: "row",
     alignItems: "center",
     gap: { xs: theme.spacing[3], md: theme.spacing[2] },
-    minHeight: { xs: 52, md: 28 },
+    minHeight: { xs: 52, md: density.tightRowHeight.md },
     paddingVertical: theme.spacing[1],
     paddingHorizontal: { xs: theme.spacing[4], md: theme.spacing[2] },
     borderRadius: { xs: 0, md: theme.borderRadius.lg },
diff --git a/packages/app/src/screens/workspace/scripts/workspace-scripts-button.tsx b/packages/app/src/screens/workspace/scripts/workspace-scripts-button.tsx
index 6acd0dfe53..2f58dedfca 100644
--- a/packages/app/src/screens/workspace/scripts/workspace-scripts-button.tsx
+++ b/packages/app/src/screens/workspace/scripts/workspace-scripts-button.tsx
@@ -28,7 +28,7 @@ import type {
   WorkspaceScriptLinkTarget,
 } from "@/utils/workspace-script-links";
 import type { Theme } from "@/styles/theme";
-import { CONTROL_HEIGHTS, HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
+import { HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 import { extraMutedIconColorMapping } from "@/components/ui/icon-color";
 import { ExitCodeBadge, routeLabelKey, ScriptIcon } from "./script-marks";
 import { scriptToneColorMapping } from "./script-status";
@@ -531,10 +531,7 @@ const styles = StyleSheet.create((theme) => ({
     flexShrink: 0,
   },
   splitButton: {
-    height: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    height: HEADER_CONTROL_HEIGHT,
     flexDirection: "row",
     alignItems: "stretch",
     borderRadius: theme.borderRadius.md,
diff --git a/packages/app/src/screens/workspace/workspace-desktop-tabs-row.tsx b/packages/app/src/screens/workspace/workspace-desktop-tabs-row.tsx
index bf957a27d4..01a5ccadaf 100644
--- a/packages/app/src/screens/workspace/workspace-desktop-tabs-row.tsx
+++ b/packages/app/src/screens/workspace/workspace-desktop-tabs-row.tsx
@@ -82,6 +82,7 @@ import { buildWorkspaceKeyboardHandlerId } from "@/keyboard/handler-id";
 import type { KeyboardActionDefinition } from "@/keyboard/keyboard-action-dispatcher";
 import { WorkspaceNewTabMenuContent } from "@/screens/workspace/workspace-new-tab-menu";
 import {
+  paneContentToolbarIconSize,
   paneContentToolbarTrailingPadding,
   ToolbarButton,
   ToolbarControls,
@@ -115,6 +116,8 @@ const TAB_ICON_WIDTH = 14;
 const TAB_CONTENT_GAP = 4;
 const TAB_DROP_INDICATOR_WIDTH = 4;
 const TAB_MODIFIED_DOT_SIZE = 8;
+// The tab rail only renders in the wide layout, so the device alone picks its glyph size.
+const TAB_RAIL_GLYPH_SIZE = paneContentToolbarIconSize(false);
 const TAB_MIN_WIDTH = 64;
 const TAB_MAX_WIDTH = 160;
 const TAB_CLOSE_BUTTON_RESERVED_WIDTH = 0;
@@ -249,7 +252,7 @@ function WorkspaceNewTabButton({
         testID="workspace-new-tab-button"
         style={placement === "inline" ? styles.inlineNewTabButton : undefined}
       >
-        <ThemedPlus size={14} uniProps={extraMutedColorMapping} />
+        <ThemedPlus size={TAB_RAIL_GLYPH_SIZE} uniProps={extraMutedColorMapping} />
       </ToolbarButton>
       <WorkspaceNewTabMenuContent
         serverId={serverId}
@@ -298,11 +301,11 @@ function WorkspacePaneToolbarActions({
   const splitDownKeys = useShortcutKeys("workspace-pane-split-down");
   const splitActionsVisible = showSplitActions && Boolean(onSplitRight && onSplitDown);
   const splitRightLeading = useMemo(
-    () => <ThemedColumns2 size={14} uniProps={extraMutedColorMapping} />,
+    () => <ThemedColumns2 size={TAB_RAIL_GLYPH_SIZE} uniProps={extraMutedColorMapping} />,
     [],
   );
   const splitDownLeading = useMemo(
-    () => <ThemedRows2 size={14} uniProps={extraMutedColorMapping} />,
+    () => <ThemedRows2 size={TAB_RAIL_GLYPH_SIZE} uniProps={extraMutedColorMapping} />,
     [],
   );
   const splitRightTrailing = useMemo(
@@ -341,9 +344,9 @@ function WorkspacePaneToolbarActions({
           onPress={onTogglePaneMaximized}
         >
           {paneMaximized ? (
-            <ThemedMinimize size={14} uniProps={extraMutedColorMapping} />
+            <ThemedMinimize size={TAB_RAIL_GLYPH_SIZE} uniProps={extraMutedColorMapping} />
           ) : (
-            <ThemedMaximize size={14} uniProps={extraMutedColorMapping} />
+            <ThemedMaximize size={TAB_RAIL_GLYPH_SIZE} uniProps={extraMutedColorMapping} />
           )}
         </ToolbarButton>
       ) : null}
@@ -354,7 +357,7 @@ function WorkspacePaneToolbarActions({
             label={t("workspace.git.actions.moreActions")}
             testID="workspace-split-pane-menu"
           >
-            <ThemedEllipsis size={14} uniProps={extraMutedColorMapping} />
+            <ThemedEllipsis size={TAB_RAIL_GLYPH_SIZE} uniProps={extraMutedColorMapping} />
           </ToolbarButton>
           <DropdownMenuContent
             side="bottom"
@@ -409,7 +412,7 @@ function WorkspaceExitFocusModeButton({
         testID="workspace-exit-focus-mode"
         onPress={onPress}
       >
-        <ThemedX size={14} uniProps={mutedColorMapping} />
+        <ThemedX size={TAB_RAIL_GLYPH_SIZE} uniProps={mutedColorMapping} />
       </ToolbarButton>
     </View>
   );
diff --git a/packages/app/src/styles/density.ts b/packages/app/src/styles/density.ts
index d29547ee88..1e66a555c0 100644
--- a/packages/app/src/styles/density.ts
+++ b/packages/app/src/styles/density.ts
@@ -1,33 +1,36 @@
+import {
+  bySizing,
+  iconSizeFor,
+  TOOLBAR_CONTROL_HEIGHT,
+  TOUCH_TARGET,
+  type IconSize,
+} from "@/components/ui/control-geometry";
 import { isCompactBreakpoint } from "@/constants/layout";
-import { ICON_SIZE, type Theme } from "@/styles/theme";
+import type { Theme } from "@/styles/theme";
 
 /**
- * Density sizes for surfaces that opt into touch sizing: rows and icons grow on compact
- * layouts and keep their desktop sizes from the `md` breakpoint up. Plain theme tokens stay
- * desktop-sized everywhere, so a surface migrates by swapping its sizes for these.
+ * Density sizes for surfaces that opt into touch sizing: rows and icons take their touch sizes
+ * where controls do (see `resolveControlSizing`) and their pointer sizes elsewhere. Plain theme
+ * tokens stay pointer-sized everywhere, so a surface migrates by swapping its sizes for these.
  *
  * Style values are Unistyles breakpoint values, resolved inside `StyleSheet.create`. Icon sizes
  * are props, so icons take them through `DensityIcon` or a `densityIconProps` mapping.
  */
 
-export type DensityIconSize = keyof typeof ICON_SIZE;
-
-const COMPACT_ICON_SIZE: Record<DensityIconSize, number> = { xs: 14, sm: 18, md: 20, lg: 24 };
-
-// Compact layouts end where `md` begins; see `isCompactBreakpoint`.
-function byLayout<T>(compact: T, desktop: T) {
-  return { xs: compact, md: desktop };
-}
+export type DensityIconSize = IconSize;
 
 export const density = {
   /** A list row such as a sidebar entry. */
-  rowHeight: byLayout(44, 36),
-  /** A row in a tight group, such as the sidebar's navigation rows. */
-  tightRowHeight: byLayout(36, 28),
+  rowHeight: bySizing({ touch: TOUCH_TARGET, pointer: 36 }),
+  /** A row in a tight group, such as the sidebar's navigation rows. Touch-sized it is a full row. */
+  tightRowHeight: bySizing({ touch: TOUCH_TARGET, pointer: 28 }),
   /** A square icon-only button that sits in a row or toolbar. */
-  iconButton: byLayout(44, 28),
-  /** The space between two blocks of rich text, such as Markdown paragraphs, code and images. */
-  blockGap: byLayout(12, 16),
+  iconButton: TOOLBAR_CONTROL_HEIGHT,
+  /**
+   * The space between two blocks of rich text, such as Markdown paragraphs, code and images.
+   * Reading rhythm, not a touch target, so it follows the layout alone.
+   */
+  blockGap: { xs: 12, md: 16 },
 };
 
 /** Resolves a density value for a prop, which Unistyles cannot resolve on its own. */
@@ -37,7 +40,7 @@ export function resolveDensity<T>(rt: { breakpoint?: string }, value: { xs: T; m
 
 /** The width or height of a slot that holds an icon of `size`. */
 export function densityIconBox(size: DensityIconSize) {
-  return byLayout(COMPACT_ICON_SIZE[size], ICON_SIZE[size]);
+  return bySizing(iconSizeFor(size));
 }
 
 export function densityIconSize(rt: { breakpoint?: string }, size: DensityIconSize): number {
diff --git a/packages/app/src/workspace/open-in-editor/button.tsx b/packages/app/src/workspace/open-in-editor/button.tsx
index e2b0530a82..5df614ec50 100644
--- a/packages/app/src/workspace/open-in-editor/button.tsx
+++ b/packages/app/src/workspace/open-in-editor/button.tsx
@@ -27,7 +27,7 @@ import { planWorkspaceOpenTargets } from "@/workspace/open-in-editor/planner";
 import type { Theme } from "@/styles/theme";
 import { ForgeBrandIcon } from "@/git/forge-icon";
 import { getForgePresentation } from "@/git/forge";
-import { CONTROL_HEIGHTS, HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
+import { HEADER_CONTROL_HEIGHT } from "@/components/ui/control-geometry";
 import { extraMutedIconColorMapping } from "@/components/ui/icon-button-chrome";
 
 interface WorkspaceOpenInEditorButtonProps {
@@ -297,10 +297,7 @@ const styles = StyleSheet.create((theme) => ({
     flexShrink: 0,
   },
   splitButton: {
-    height: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    height: HEADER_CONTROL_HEIGHT,
     flexDirection: "row",
     alignItems: "stretch",
     borderRadius: theme.borderRadius.md,
@@ -317,10 +314,7 @@ const styles = StyleSheet.create((theme) => ({
     position: "relative",
   },
   splitButtonPrimaryIconOnly: {
-    width: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    width: HEADER_CONTROL_HEIGHT,
     paddingHorizontal: 0,
     justifyContent: "center",
     position: "relative",
@@ -348,10 +342,7 @@ const styles = StyleSheet.create((theme) => ({
     transform: [{ scale: 0.8 }],
   },
   splitButtonCaret: {
-    width: {
-      xs: CONTROL_HEIGHTS.sm,
-      md: HEADER_CONTROL_HEIGHT,
-    },
+    width: HEADER_CONTROL_HEIGHT,
     alignItems: "center",
     justifyContent: "center",
     borderLeftWidth: theme.borderWidth[1],