Put resize handles as invisible bars on edges of inspector window

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Inspector/GraphInspectorView.cs

 {
     public class GraphInspectorView : VisualElement, IDisposable
     {
+        enum ResizeDirection
+        {
+            Any,
+            Vertical,
+            Horizontal
+        }
+
         int m_SelectionHash;
 
         VisualElement m_PropertyItems;
             foreach (var property in m_Graph.properties)
                 m_PropertyItems.Add(new ShaderPropertyView(m_Graph, property));
 
-            var resizeHandle = new Label { name = "resize", text = "" };
-            resizeHandle.AddManipulator(new Draggable(OnResize));
-            Add(resizeHandle);
+            var resizeHandleTop = new Label { name = "resize-top", text = "" };
+            resizeHandleTop.AddManipulator(new Draggable(mouseDelta => OnResize(mouseDelta, ResizeDirection.Vertical, true)));
+            Add(resizeHandleTop);
+
+            var resizeHandleRight = new Label { name = "resize-right", text = "" };
+            resizeHandleRight.AddManipulator(new Draggable(mouseDelta => OnResize(mouseDelta, ResizeDirection.Horizontal, false)));
+            Add(resizeHandleRight);
+
+            var resizeHandleLeft = new Label { name = "resize-left", text = "" };
+            resizeHandleLeft.AddManipulator(new Draggable(mouseDelta => OnResize(mouseDelta, ResizeDirection.Horizontal, true)));
+            Add(resizeHandleLeft);
+
+            var resizeHandleBottom = new Label { name = "resize-bottom", text = "" };
+            resizeHandleBottom.AddManipulator(new Draggable(mouseDelta => OnResize(mouseDelta, ResizeDirection.Vertical, false)));
+            Add(resizeHandleBottom);
 
             // Nodes missing custom editors:
             // - PropertyNode
             };
         }
 
-        void OnResize(Vector2 resizeDelta)
+        void OnResize(Vector2 resizeDelta, ResizeDirection direction, bool moveWhileResize)
+
+            if (direction == ResizeDirection.Vertical)
+            {
+                normalizedResizeDelta.x = 0f;
+            }
+            else if (direction == ResizeDirection.Horizontal)
+            {
+                normalizedResizeDelta.y = 0f;
+            }
+
+            if (moveWhileResize)
+            {
+                style.positionLeft += normalizedResizeDelta.x;
+                style.positionTop += normalizedResizeDelta.y;
+
+                normalizedResizeDelta *= -1f;
+            }
 
             style.width = Mathf.Max(style.width + normalizedResizeDelta.x, 60f);
             style.height = Mathf.Max(style.height + normalizedResizeDelta.y, 60f);

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Resources/Styles/MaterialGraph.uss

     padding-bottom: 4;
 }
 
-GraphInspectorView > #resize {
-    cursor: resize-up-left;
-    background-image : resource("GraphView/Nodes/NodeChevronLeft.png");
+GraphInspectorView > #resize-right {
+    cursor: resize-horizontal;
+    background-color: rgba(0, 0, 0, 0);
-    width: 16;
-    height: 16;
+    width: 5;
+    position-right: 0;
+    position-top: 0;
+    position-bottom: 0;
+}
+
+GraphInspectorView > #resize-left {
+    cursor: resize-horizontal;
+    background-color: rgba(0, 0, 0, 0);
+    position-type: absolute;
+    width: 5;
+    position-left: 0;
+    position-top: 0;
+    position-bottom: 0;
+    padding-left: 0;
+    margin-left: 0;
+}
+
+GraphInspectorView > #resize-top {
+    cursor: resize-vertical;
+    background-color: rgba(0, 0, 0, 0);
+    position-type: absolute;
+    height: 5;
+    position-left: 0;
+    position-right: 0;
+    position-top: 0;
+    padding-top: 0;
+    margin-top: 0;
+}
+
+GraphInspectorView > #resize-bottom {
+    cursor: resize-vertical;
+    background-color: rgba(0, 0, 0, 0);
+    position-type: absolute;
+    height: 5;
+    position-left: 0;
     position-right: 0;
     position-bottom: 0;
 }