add menu bar

frontend/src/App.js

@@ -1,19 +1,28 @@
 import React from 'react';
-import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';
-import Home from './pages/Home';
-import Invoices from './pages/Invoices';
-import Clients from './pages/Clients';
+import { BrowserRouter as Router, Route, Routes, Link } from 'react-router-dom';
+import InvoiceList from './components/InvoiceList';
+import ClientList from './components/ClientList';
+import Home from './components/Home';
 
 function App() {
   return (
     <Router>
-      <div>
+      <div style={{ padding: '20px' }}>
         <h1>Invoice Notification App</h1>
-        <Switch>
-          <Route path="/" exact component={Home} />
-          <Route path="/invoices" component={Invoices} />
-          <Route path="/clients" component={Clients} />
-        </Switch>
+
+        {/* Navigation Bar */}
+        <nav style={{ marginBottom: '20px' }}>
+          <Link to="/" style={{ marginRight: '15px' }}>Home</Link>
+          <Link to="/invoices" style={{ marginRight: '15px' }}>Invoices</Link>
+          <Link to="/clients">Clients</Link>
+        </nav>
+
+        {/* Routes */}
+        <Routes>
+          <Route path="/" element={<Home />} />
+          <Route path="/invoices" element={<InvoiceList />} />
+          <Route path="/clients" element={<ClientList />} />
+        </Routes>
       </div>
     </Router>
   );