Implemented new nav bar with selected animation

lib/presentation/widgets/navbar_item.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:game_tracker/core/custom_theme.dart';
 
 /// A navigation bar item widget that represents a single tab in a navigation bar.
 /// - [index]: The index of the tab.
@@ -35,7 +36,45 @@ class NavbarItem extends StatefulWidget {
   State<NavbarItem> createState() => _NavbarItemState();
 }
 
-class _NavbarItemState extends State<NavbarItem> {
+class _NavbarItemState extends State<NavbarItem>
+    with SingleTickerProviderStateMixin {
+  /// Animation controller for the scale animation
+  late AnimationController _animationController;
+
+  /// Scale animation for the icon when selected
+  late Animation<double> _scaleAnimation;
+
+  @override
+  void initState() {
+    super.initState();
+    _animationController = AnimationController(
+      duration: const Duration(milliseconds: 300),
+      vsync: this,
+    );
+
+    _scaleAnimation = Tween<double>(begin: 1.0, end: 1.2).animate(
+      CurvedAnimation(
+        parent: _animationController,
+        curve: Curves.easeInOutBack,
+      ),
+    );
+
+    if (widget.isSelected) {
+      _animationController.forward();
+    }
+  }
+
+  // Retrigger animation on selection change
+  @override
+  void didUpdateWidget(NavbarItem oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.isSelected && !oldWidget.isSelected) {
+      _animationController.forward();
+    } else if (!widget.isSelected && oldWidget.isSelected) {
+      _animationController.reverse();
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Expanded(
@@ -48,19 +87,29 @@ class _NavbarItemState extends State<NavbarItem> {
             mainAxisSize: MainAxisSize.min,
             mainAxisAlignment: MainAxisAlignment.center,
             children: [
-              Icon(
-                widget.icon,
-                color: widget.isSelected ? Colors.white : Colors.black,
+              ScaleTransition(
+                scale: widget.isSelected
+                    ? _scaleAnimation
+                    : const AlwaysStoppedAnimation(1.0),
+                child: Icon(
+                  widget.icon,
+                  color: widget.isSelected
+                      ? CustomTheme.navBarItemSelectedColor
+                      : CustomTheme.navBarItemUnselectedColor,
+                  size: 26,
+                ),
               ),
               const SizedBox(height: 4),
               Text(
                 widget.label,
                 style: TextStyle(
-                  color: widget.isSelected ? Colors.white : Colors.black,
-                  fontSize: 12,
+                  color: widget.isSelected
+                      ? CustomTheme.navBarItemSelectedColor
+                      : CustomTheme.navBarItemUnselectedColor,
+                  fontSize: widget.isSelected ? 12 : 11,
                   fontWeight: widget.isSelected
                       ? FontWeight.bold
-                      : FontWeight.normal,
+                      : FontWeight.w500,
                 ),
               ),
             ],
@@ -69,4 +118,10 @@ class _NavbarItemState extends State<NavbarItem> {
       ),
     );
   }
+
+  @override
+  void dispose() {
+    _animationController.dispose();
+    super.dispose();
+  }
 }