move navbar widget to its own file

lib/presentation/widgets/navbar_item.dart

@@ -1,7 +1,18 @@
-import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
 
 class NavbarItem extends StatefulWidget {
-  const NavbarItem({super.key});
+
+  final int currentIndex;
+  final int index;
+  final IconData icon;
+  final String label;
+  final Function(int) onTabTapped;
+
+  const NavbarItem(
+        {super.key, required this.currentIndex, required this.index,
+          required this.icon, required this.label, required this.onTabTapped
+        }
+      );
 
   @override
   State<NavbarItem> createState() => _NavbarItemState();
@@ -10,6 +21,36 @@ class NavbarItem extends StatefulWidget {
 class _NavbarItemState extends State<NavbarItem> {
   @override
   Widget build(BuildContext context) {
-    return const Placeholder();
+
+    bool isSelected = widget.currentIndex == widget.index;
+
+    return Expanded(
+      child: GestureDetector(
+        onTap: () => widget.onTabTapped(widget.index),
+        behavior: HitTestBehavior.opaque,
+        child: Padding(
+          padding: const EdgeInsets.symmetric(vertical: 5.0),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              Icon(
+                widget.icon,
+                color: isSelected ? Colors.white : Colors.black,
+              ),
+              const SizedBox(height: 4),
+              Text(
+                widget.label,
+                style: TextStyle(
+                  color: isSelected ? Colors.white : Colors.black,
+                  fontSize: 12,
+                  fontWeight: isSelected ? FontWeight.bold : FontWeight.normal,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
   }
 }