diff --git a/start.py b/start.py
index 3c57ec9..bdb16f6 100644
--- a/start.py
+++ b/start.py
@@ -1,5 +1,6 @@
-import os
+import signal
 import sys
+import traceback
 
 from PyQt6.QtWidgets import QApplication
 
@@ -7,30 +8,28 @@ from core.app import StickyNoteApp
 
 
 def main() -> int:
-    os.environ["QT_AUTO_SCREEN_SCALE_FACTOR"] = "1"
+    signal.signal(signal.SIGINT, signal.SIG_DFL)
 
-    QApplication.setQuitOnLastWindowClosed(False)
-
-    app = QApplication.instance()
-    if app is None:
-        app = QApplication(sys.argv)
-
-    app.setQuitLockEnabled(False)
-
-    existing = getattr(app, "_sticky_note_instance", None)
-    if existing is not None:
-        existing.raise_()
-        existing.activateWindow()
-        return 0
+    app = QApplication(sys.argv)
 
     window = StickyNoteApp()
-
-    app._sticky_note_instance = window
-
     window.show()
 
-    return app.exec()
+    try:
+        return app.exec()
+    except KeyboardInterrupt:
+        try:
+            window.safe_exit()
+        except Exception:
+            traceback.print_exc()
+
+        return 0
+    except SystemExit:
+        return 0
+    except Exception:
+        traceback.print_exc()
+        return 1
 
 
 if __name__ == "__main__":
-    raise SystemExit(main())
+    raise SystemExit(main())
\ No newline at end of file