diff --git a/studio/Python/tinymovr/gui/helpers.py b/studio/Python/tinymovr/gui/helpers.py
index d343e527..bc9e5944 100644
--- a/studio/Python/tinymovr/gui/helpers.py
+++ b/studio/Python/tinymovr/gui/helpers.py
@@ -201,6 +201,8 @@
 
 app_stylesheet_dark = """
 
+QSplitter::handle { background-color: black; }
+
 /* --------------------------------------- QPushButton -----------------------------------*/
 
     QPushButton {
diff --git a/studio/Python/tinymovr/gui/window.py b/studio/Python/tinymovr/gui/window.py
index e6c18b0f..32e657bf 100644
--- a/studio/Python/tinymovr/gui/window.py
+++ b/studio/Python/tinymovr/gui/window.py
@@ -34,6 +34,7 @@
     QLabel,
     QMessageBox,
     QTreeWidgetItem,
+    QSplitter
 )
 from PySide6.QtGui import QAction
 import pyqtgraph as pg
@@ -110,6 +111,10 @@ def __init__(self, app, arguments, logger):
         self.status_label = QLabel()
         self.status_label.setStyleSheet("margin: 5px;")
 
+        # Create splitter and add frames
+        self.splitter = QSplitter(QtCore.Qt.Horizontal)
+        self.splitter.setHandleWidth(0)
+
         self.left_frame = QFrame(self)
         self.left_layout = QVBoxLayout()
         self.left_layout.addWidget(self.tree_widget)
@@ -127,9 +132,11 @@ def __init__(self, app, arguments, logger):
         self.right_layout.setContentsMargins(0, 0, 0, 0)
         self.right_frame.setLayout(self.right_layout)
 
-        main_layout = QHBoxLayout()
-        main_layout.addWidget(self.left_frame)
-        main_layout.addWidget(self.right_frame)
+        self.splitter.addWidget(self.left_frame)
+        self.splitter.addWidget(self.right_frame)
+
+        main_layout = QVBoxLayout()
+        main_layout.addWidget(self.splitter)
         main_layout.setSpacing(0)
         main_layout.setContentsMargins(0, 0, 0, 0)