diff --git a/vba_code_kukan_detail_master.txt b/vba_code_kukan_detail_master.txt
index b791d6b..76b6985 100644
--- a/vba_code_kukan_detail_master.txt
+++ b/vba_code_kukan_detail_master.txt
@@ -146,6 +146,12 @@ Sub ImportMasterDetailData()
     
     lines = Split(textContent, vbCrLf)
     
+    ' === Clear all data rows before import ===
+    lastRow = wsTarget.Cells(wsTarget.Rows.Count, "C").End(xlUp).Row
+    If lastRow >= 7 Then
+        wsTarget.Range("A7:P" & lastRow).ClearContents
+    End If
+    
     If UBound(lines) < 1 Then
         MsgBox "No data in CSV.", vbExclamation
         Exit Sub