changed color theme to be black and added the ability to enter the amount in the recipient’s currency

frontend/pweb/lib/pages/signup/form/buttons.dart

@@ -1,16 +0,0 @@
-import 'package:flutter/material.dart';
-
-
-class SignUpBackButton extends StatelessWidget {
-  const SignUpBackButton({super.key});
-
-  @override
-  Widget build(BuildContext context) => Row(
-    children: [
-      IconButton(
-        onPressed: Navigator.of(context).pop,
-        icon: const Icon(Icons.arrow_back),
-      ),
-    ],
-  );
-}