Add error handling

backend/app.js

@@ -9,4 +9,8 @@ app.use(express.json());
 
 app.use('/v1/notes', notesRoutes);
 
+app.use((req, res) => {
+   res.status(404).json({ error: `Requested path is invalid or does not exist: ${req.method} ${req.originalUrl}` });
+ });
+
 export default app;

frontend/src/styles/home.css

@@ -22,10 +22,10 @@
   .main-head {
     font-size: 5rem;
     color: #6dd6f4;
-    margin: 2px 0px 24px 22px;
+    margin: 6px 0px 24px 22px;
     font-family: "Sulphur Point", sans-serif;
     font-weight: 500;
-    letter-spacing: 3px;
+    letter-spacing: 4px;
     text-decoration: underline;
   }