Added Custom button

lib/presentation/widgets/custom_button.dart

@@ -0,0 +1,19 @@
+import 'package:cabo_counter/core/custom_theme.dart';
+import 'package:flutter/cupertino.dart';
+
+class CustomButton extends StatelessWidget {
+  final Widget child;
+  final VoidCallback? onPressed;
+  const CustomButton({super.key, required this.child, this.onPressed});
+
+  @override
+  Widget build(BuildContext context) {
+    return CupertinoButton(
+      sizeStyle: CupertinoButtonSize.medium,
+      borderRadius: BorderRadius.circular(12),
+      color: CustomTheme.buttonBackgroundColor,
+      onPressed: onPressed,
+      child: child,
+    );
+  }
+}