diff --git a/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.test.ts b/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.test.ts
index 0e9921b3dc8..8cf54832c58 100644
--- a/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.test.ts
+++ b/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.test.ts
@@ -7,6 +7,14 @@ import {
 } from './right-sidebar-primary-action-layout'
 
 describe('right sidebar primary action layout classes', () => {
+  it('fills the sidebar row while stretching wrapped and direct primary buttons', () => {
+    expect(RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS).toContain('flex')
+    expect(RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS).toContain('w-full')
+    expect(RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS).toContain('[&>*:first-child]:flex-1')
+    expect(RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS).toContain('[&>*:first-child>button]:w-full')
+    expect(RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS).toContain('[&>button:first-child]:w-full')
+  })
+
   it('lets split-button primaries shrink inside the minimum-width sidebar', () => {
     expect(RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS).toContain('min-w-0')
     expect(RIGHT_SIDEBAR_MORPHING_PRIMARY_BUTTON_CLASS).toContain('shrink')
diff --git a/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.ts b/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.ts
index 4ea850c8ac3..514aa28f702 100644
--- a/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.ts
+++ b/src/renderer/src/components/right-sidebar/right-sidebar-primary-action-layout.ts
@@ -1,7 +1,8 @@
-// Why: sidebar primaries rotate labels as git/review state changes. Content-width
-// reads better than full-bleed; preferred width reduces jump between states; the
+// Why: sidebar primaries rotate labels as git/review state changes. Filling the
+// pane keeps their right edge aligned with the surrounding editor chrome; the
 // primary half must shrink first so split-button chevrons never overflow.
-export const RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS = 'inline-flex min-w-0 max-w-full items-stretch'
+export const RIGHT_SIDEBAR_SPLIT_ACTION_ROW_CLASS =
+  'flex w-full min-w-0 items-stretch [&>*:first-child]:flex-1 [&>*:first-child>button]:w-full [&>button:first-child]:w-full'
 
 export const RIGHT_SIDEBAR_MORPHING_PRIMARY_BUTTON_CLASS = 'w-[10.5rem] min-w-0 max-w-full shrink'