first commit

src/App.jsx

@@ -0,0 +1,29 @@
+import React, { useState } from 'react'
+import Sidebar from './components/Sidebar.jsx'
+import Dashboard from './components/Dashboard.jsx'
+import TripTracker from './components/TripTracker.jsx'
+
+/**
+ * App — root layout component.
+ * Implements a two-panel CSS Grid: fixed sidebar + scrollable main viewport.
+ * Owns the active-page state so sidebar navigation drives content rendering.
+ */
+export default function App() {
+  const [activePage, setActivePage] = useState('dashboard')
+
+  function renderPage() {
+    switch (activePage) {
+      case 'trip-tracker': return <TripTracker />
+      default:             return <Dashboard />
+    }
+  }
+
+  return (
+    <div className="app-shell">
+      <Sidebar activePage={activePage} onNavigate={setActivePage} />
+      <main className="main-viewport">
+        {renderPage()}
+      </main>
+    </div>
+  )
+}