diff --git a/web/src/hooks/useViewportHeight.test.ts b/web/src/hooks/useViewportHeight.test.ts
index 8262af94..5a2d6664 100644
--- a/web/src/hooks/useViewportHeight.test.ts
+++ b/web/src/hooks/useViewportHeight.test.ts
@@ -60,4 +60,47 @@ describe('useViewportHeight update logic', () => {
 
         expect(root.style.getPropertyValue('--app-viewport-height')).toBe('')
     })
+
+    it('resets page scroll when keyboard is open', () => {
+        const scrollToSpy = vi.spyOn(window, 'scrollTo').mockImplementation(() => {})
+
+        // Simulate: keyboard open AND page has been scrolled by iOS
+        Object.defineProperty(window, 'scrollY', { value: 120, configurable: true })
+
+        const viewportHeight = 400
+        const windowHeight = 800
+        const diff = windowHeight - viewportHeight
+        if (diff > 1) {
+            root.style.setProperty('--app-viewport-height', `${viewportHeight}px`)
+            if (window.scrollY > 0) {
+                window.scrollTo(0, 0)
+            }
+        }
+
+        expect(scrollToSpy).toHaveBeenCalledWith(0, 0)
+
+        // Cleanup
+        Object.defineProperty(window, 'scrollY', { value: 0, configurable: true })
+        scrollToSpy.mockRestore()
+    })
+
+    it('does not reset scroll when page is not scrolled', () => {
+        const scrollToSpy = vi.spyOn(window, 'scrollTo').mockImplementation(() => {})
+
+        Object.defineProperty(window, 'scrollY', { value: 0, configurable: true })
+
+        const viewportHeight = 400
+        const windowHeight = 800
+        const diff = windowHeight - viewportHeight
+        if (diff > 1) {
+            root.style.setProperty('--app-viewport-height', `${viewportHeight}px`)
+            if (window.scrollY > 0) {
+                window.scrollTo(0, 0)
+            }
+        }
+
+        expect(scrollToSpy).not.toHaveBeenCalled()
+
+        scrollToSpy.mockRestore()
+    })
 })
diff --git a/web/src/hooks/useViewportHeight.ts b/web/src/hooks/useViewportHeight.ts
index b8c500c8..fbf206f3 100644
--- a/web/src/hooks/useViewportHeight.ts
+++ b/web/src/hooks/useViewportHeight.ts
@@ -32,15 +32,26 @@ export function useViewportHeight(): void {
             const diff = window.innerHeight - viewport.height
             if (diff > 1) {
                 root.style.setProperty('--app-viewport-height', `${viewport.height}px`)
+                // On iOS PWA (black-translucent status bar + viewport-fit=cover),
+                // the browser scrolls the page upward when the keyboard opens to
+                // keep the focused input visible. This pushes the header behind
+                // the iOS status bar. Reset the page scroll so the app stays
+                // pinned to the top — the inner flex layout already handles
+                // keeping the composer visible.
+                if (window.scrollY > 0) {
+                    window.scrollTo(0, 0)
+                }
             } else {
                 root.style.removeProperty('--app-viewport-height')
             }
         }
 
         viewport.addEventListener('resize', update)
+        viewport.addEventListener('scroll', update)
 
         return () => {
             viewport.removeEventListener('resize', update)
+            viewport.removeEventListener('scroll', update)
             root.style.removeProperty('--app-viewport-height')
         }
     }, [])