diff --git a/internal/editor/cursor_test.go b/internal/editor/cursor_test.go
index 06dea1b..993fe68 100644
--- a/internal/editor/cursor_test.go
+++ b/internal/editor/cursor_test.go
@@ -111,6 +111,49 @@ func TestTapLocalY_WindowRelative(t *testing.T) {
 	}
 }
 
+// TestTapToPosition_WindowBaseOffset is a regression test for the
+// window-relative GlyphLayout bug: the GlyphLayout is shaped from the visible
+// window alone, so its ByteOffsets are relative to the window start
+// (IMEWindowStartByte). SetCursorFromPoint must add that base to produce an
+// absolute file offset. Before the fix, a tap on a scrolled large file set the
+// cursor to a window-relative offset (near the file start), so the IME
+// selection snapped to the window top on every tap.
+func TestTapToPosition_WindowBaseOffset(t *testing.T) {
+	lh := float64(EditorLineHeight())
+	const lines = 40
+	gl := ui.GlyphLayout{LineHeight: EditorLineHeight()}
+	for i := 0; i < lines; i++ {
+		for _, x := range []ui.Dp{10, 20} {
+			gl.ByteOffsets = append(gl.ByteOffsets, i*2) // window-relative
+			gl.X = append(gl.X, x)
+			gl.Y = append(gl.Y, ui.Dp(float64(i+1)*lh))
+			gl.Advance = append(gl.Advance, 10)
+		}
+	}
+	TheState = NewState()
+	TheState.Editor.GlyphLayout = gl
+	TheState.Editor.IMEWindowStartByte = 47618 // window starts deep in the file
+	TheState.ScrollOffset = 16500
+
+	// Tap ~3 lines below the top of the window.
+	regionTop := ui.Dp(114)
+	ptY := regionTop + ui.Dp(3*lh)
+	localY := tapLocalY(ptY, regionTop, TheState.ScrollOffset)
+	SetCursorFromPoint(15, localY)
+
+	// Window line 3 is window-relative byte 6, so the absolute cursor must be
+	// base (47618) + 6 = 47624. Before the fix it would be 6 (window-relative),
+	// which is the file start, not the tapped line.
+	want := 47618 + 6
+	if TheState.Editor.CursorPosition < want-2 || TheState.Editor.CursorPosition > want+2 {
+		t.Errorf("cursor = %d, want %d (base 47618 + window byte 6); window-relative offset bug?", TheState.Editor.CursorPosition, want)
+	}
+	// Regression: the buggy cursor would be ~6 (window-relative, near file start).
+	if TheState.Editor.CursorPosition < 100 {
+		t.Errorf("cursor = %d, window-relative offset leaked (should be absolute ~%d)", TheState.Editor.CursorPosition, want)
+	}
+}
+
 // TestTapToPosition_LargeFileScrolled is the end-to-end regression: with a
 // window-relative GlyphLayout and a deep scroll, a tap a few lines below the top
 // of the window must land on that window line, NOT be clamped to the last window
diff --git a/internal/editor/state.go b/internal/editor/state.go
index 60d82b6..74fe999 100644
--- a/internal/editor/state.go
+++ b/internal/editor/state.go
@@ -341,7 +341,6 @@ func HandleCursorMove(delta int) {
 	if newPos > maxPos {
 		newPos = maxPos
 	}
-	log.Printf("HandleCursorMove: old=%d, new=%d (max=%d)", TheState.Editor.CursorPosition, newPos, maxPos)
 	TheState.Editor.CursorPosition = newPos
 }
 
@@ -352,11 +351,9 @@ func HandleKeyDown(data any) {
 	if TheState.Editor.TooLarge {
 		return
 	}
-	log.Printf("HandleKeyDown: received data of type %T: %v", data, data)
 	switch v := data.(type) {
 	case key.EditEvent:
 		// Text input from IME / keyboard.
-		log.Printf("HandleKeyDown: EditEvent text=%q range=%+v", v.Text, v.Range)
 		if v.Text == "\b" {
 			// Backspace character (legacy / hardware): delete one char before
 			// the cursor.
@@ -370,7 +367,6 @@ func HandleKeyDown(data any) {
 			HandleReplaceRange(v.Range.Start, v.Range.End, v.Text)
 		}
 	case key.Name:
-		log.Printf("HandleKeyDown: name=%q", v)
 		switch v {
 		case key.NameLeftArrow:
 			HandleCursorMove(-1)
@@ -398,6 +394,15 @@ func HandleKeyDown(data any) {
 	}
 }
 
+// glyphBase returns the absolute file byte offset at the start of the current
+// visible window. The GlyphLayout is shaped from the visible window alone, so
+// every one of its ByteOffsets is relative to this base; adding it yields an
+// absolute file offset. For a whole-file window (small files, or scroll 0) the
+// base is 0 and this is a no-op.
+func glyphBase() int {
+	return TheState.Editor.IMEWindowStartByte
+}
+
 // HandleHome moves the cursor to the start of the current visual line.
 func HandleHome() {
 	layout := TheState.Editor.GlyphLayout
@@ -405,8 +410,12 @@ func HandleHome() {
 		return
 	}
 
-	pos := TheState.Editor.CursorPosition
-	// Find current glyph index.
+	base := glyphBase()
+	pos := TheState.Editor.CursorPosition - base
+	if pos < 0 {
+		pos = 0
+	}
+	// Find current glyph index (offsets are window-relative).
 	idx := sort.Search(len(layout.ByteOffsets), func(i int) bool {
 		return layout.ByteOffsets[i] >= pos
 	})
@@ -424,7 +433,7 @@ func HandleHome() {
 			break
 		}
 	}
-	TheState.Editor.CursorPosition = layout.ByteOffsets[targetIdx]
+	TheState.Editor.CursorPosition = base + layout.ByteOffsets[targetIdx]
 }
 
 // HandleEnd moves the cursor to the end of the current visual line.
@@ -434,8 +443,12 @@ func HandleEnd() {
 		return
 	}
 
-	pos := TheState.Editor.CursorPosition
-	// Find current glyph index.
+	base := glyphBase()
+	pos := TheState.Editor.CursorPosition - base
+	if pos < 0 {
+		pos = 0
+	}
+	// Find current glyph index (offsets are window-relative).
 	idx := sort.Search(len(layout.ByteOffsets), func(i int) bool {
 		return layout.ByteOffsets[i] >= pos
 	})
@@ -456,7 +469,8 @@ func HandleEnd() {
 
 	// Position after the last character of the line.
 	// If it's a newline, it's the newline itself.
-	start := layout.ByteOffsets[targetIdx]
+	// start is window-relative; convert to an absolute file offset.
+	start := base + layout.ByteOffsets[targetIdx]
 	buf := TheState.Editor.ChunkedBuffer
 	var fileContent string
 	if buf != nil {
@@ -503,8 +517,12 @@ func HandleVerticalCursorMove(up bool) {
 		return
 	}
 
-	pos := TheState.Editor.CursorPosition
-	// Find current glyph index.
+	base := glyphBase()
+	pos := TheState.Editor.CursorPosition - base
+	if pos < 0 {
+		pos = 0
+	}
+	// Find current glyph index (offsets are window-relative).
 	idx := sort.Search(len(layout.ByteOffsets), func(i int) bool {
 		return layout.ByteOffsets[i] >= pos
 	})
@@ -578,7 +596,7 @@ func HandleVerticalCursorMove(up bool) {
 		}
 	}
 
-	TheState.Editor.CursorPosition = layout.ByteOffsets[targetIdx]
+	TheState.Editor.CursorPosition = base + layout.ByteOffsets[targetIdx]
 }
 
 // HandleDelete removes the character after the cursor.
@@ -617,7 +635,6 @@ func HandleInsert(s string) {
 
 // HandleBackspace removes the character before the cursor.
 func HandleBackspace() {
-	log.Printf("HandleBackspace: CursorPosition=%d", TheState.Editor.CursorPosition)
 	pos := TheState.Editor.CursorPosition
 	if pos == 0 {
 		return
@@ -749,9 +766,6 @@ func markDirty() {
 
 // EditorLayout computes the element tree for the editor page.
 func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
-	// Debug: ensure we are actually running this
-	// fmt.Printf("DEBUG: EditorLayout called\n")
-
 	margin := ui.Dp(10)
 
 	// --- Top bar: filename on row 1, icons on row 2 ---
@@ -1007,6 +1021,7 @@ func SetCursorFromPoint(x, y float64) {
 		return
 	}
 
+	base := glyphBase()
 	lineHeight := float64(EditorLineHeight())
 
 	// 1. Identify the intended line index based on y
@@ -1091,7 +1106,7 @@ func SetCursorFromPoint(x, y float64) {
 	// 4. Check if tap is to the right of the last character
 	if rightmostIdx != -1 && x > rightmostX {
 		// Position at the end of the line content, before any trailing newline.
-		start := layout.ByteOffsets[rightmostIdx]
+		start := base + layout.ByteOffsets[rightmostIdx]
 		buf := TheState.Editor.ChunkedBuffer
 		var fileContent string
 		if buf != nil {
@@ -1132,6 +1147,6 @@ func SetCursorFromPoint(x, y float64) {
 		}
 	}
 	if bestIdx != -1 {
-		TheState.Editor.CursorPosition = layout.ByteOffsets[bestIdx]
+		TheState.Editor.CursorPosition = base + layout.ByteOffsets[bestIdx]
 	}
 }