flutter-examples/expense_planner/lib/main.dart

import 'package:flutter/material.dart';

import 'example.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Personal Expenses',
      theme: ThemeData(
          primarySwatch: Colors.purple,
          colorScheme: ColorScheme.fromSwatch(primarySwatch: Colors.purple)
              .copyWith(secondary: Colors.amber),
          fontFamily: 'Quicksand',
          textTheme: ThemeData.light().textTheme.copyWith(
                titleMedium: TextStyle(
                  fontFamily: 'OpenSans',
                  fontWeight: FontWeight.bold,
                  fontSize: 18,
                ),
                labelLarge: TextStyle(color: Colors.white),
              ),
          appBarTheme: AppBarTheme(
            titleTextStyle: TextStyle(
              fontFamily: 'OpenSans',
              fontSize: 20,
              fontWeight: FontWeight.bold,
            ),
          )),
      home: const Example(),
    );
  }
}