Update lesson_graph.py

lesson_graph.py

@@ -160,7 +160,7 @@ class LessonGraph:
         Visualize the graph using Matplotlib, handling layout, labels, and interactivity.
         """
         fig, ax = plt.subplots(figsize=(14, 10))
-        pos = nx.spring_layout(self.graph, k=0.9, iterations=50)
+        pos = nx.spring_layout(self.graph, k=1.2, iterations=100)
 
         self._draw_nodes(ax, pos)
         self._draw_edges(ax, pos)
@@ -174,7 +174,7 @@ class LessonGraph:
         
         # Save the plot to a BytesIO object
         buf = BytesIO()
-        plt.savefig(buf, format="png", dpi=300, bbox_inches="tight")
+        plt.savefig(buf, format="png", dpi=300, bbox_inches="tight", pad_inches=0.5)
         buf.seek(0)
         plt.close(fig)