test_blur.dart

import 'package:flutter/material.dart';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
        double borderWidth = 3;
    Color borderColor = Colors.black;
    double borderRadius = 5;
    Color boxShadowColor = Colors.blue;
    Offset boxShadowOffset = Offset.zero;
    double boxShadowBlurRadius = 50;
    return Container(
      width: 50,
      height: 50,
      decoration: BoxDecoration(
          color: Colors.white,
          border: Border.all(width: borderWidth, color: borderColor),
          borderRadius: BorderRadius.circular(borderRadius),
          boxShadow: [
            BoxShadow(
              color: boxShadowColor,
              offset: boxShadowOffset,
              blurRadius: boxShadowBlurRadius,
            )
          ]),
    );
  }
}