frontend/src/App.tsx

import React from 'react';
import { BrowserRouter as Router, Routes, Route, Link } from 'react-router-dom';
import Home from './components/Home';
import Classify from './components/Classify';
import Validate from './components/Validate';
import Improve from './components/Improve';

const App: React.FC = () => {
  return (
    <Router>
      <div className="min-h-screen bg-gray-50">
        <nav className="bg-white shadow-sm">
          <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
            <div className="flex justify-between h-16">
              <div className="flex">
                <div className="flex-shrink-0 flex items-center">
                  <span className="text-xl font-bold text-primary-600">Text Classifier</span>
                </div>
                <div className="hidden sm:ml-6 sm:flex sm:space-x-8">
                  <Link
                    to="/"
                    className="border-transparent text-gray-500 hover:border-gray-300 hover:text-gray-700 inline-flex items-center px-1 pt-1 border-b-2 text-sm font-medium"
                  >
                    Home
                  </Link>
                  <Link
                    to="/classify"
                    className="border-transparent text-gray-500 hover:border-gray-300 hover:text-gray-700 inline-flex items-center px-1 pt-1 border-b-2 text-sm font-medium"
                  >
                    Classify
                  </Link>
                  <Link
                    to="/validate"
                    className="border-transparent text-gray-500 hover:border-gray-300 hover:text-gray-700 inline-flex items-center px-1 pt-1 border-b-2 text-sm font-medium"
                  >
                    Validate
                  </Link>
                  <Link
                    to="/improve"
                    className="border-transparent text-gray-500 hover:border-gray-300 hover:text-gray-700 inline-flex items-center px-1 pt-1 border-b-2 text-sm font-medium"
                  >
                    Improve
                  </Link>
                </div>
              </div>
            </div>
          </div>
        </nav>

        <main className="max-w-7xl mx-auto py-6 sm:px-6 lg:px-8">
          <Routes>
            <Route path="/" element={<Home />} />
            <Route path="/classify" element={<Classify />} />
            <Route path="/validate" element={<Validate />} />
            <Route path="/improve" element={<Improve />} />
          </Routes>
        </main>
      </div>
    </Router>
  );
};

export default App;