butto to import file

lib/screens/deck_import_screen.dart

@@ -1,4 +1,6 @@
 import 'dart:convert';
+
+import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:practice_engine/practice_engine.dart';
@@ -271,6 +273,30 @@ class _DeckImportScreenState extends State<DeckImportScreen> {
     showTopSnackBar(context, message: 'JSON copied to clipboard');
   }
 
+  Future<void> _pickJsonFile() async {
+    final result = await FilePicker.platform.pickFiles(
+      type: FileType.custom,
+      allowedExtensions: ['json'],
+      withData: true,
+    );
+    if (result == null || result.files.isEmpty || !mounted) return;
+    final file = result.files.single;
+    if (file.bytes == null) {
+      if (mounted) {
+        showTopSnackBar(context, message: 'Could not read file content');
+      }
+      return;
+    }
+    final text = utf8.decode(file.bytes!);
+    setState(() {
+      _errorMessage = null;
+      _jsonController.text = text;
+    });
+    if (mounted) {
+      showTopSnackBar(context, message: 'File loaded');
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -393,6 +419,11 @@ class _DeckImportScreenState extends State<DeckImportScreen> {
                         Row(
                           mainAxisSize: MainAxisSize.min,
                           children: [
+                            TextButton.icon(
+                              onPressed: _pickJsonFile,
+                              icon: const Icon(Icons.folder_open),
+                              label: const Text('Select file'),
+                            ),
                             TextButton.icon(
                               onPressed: _loadSampleDeck,
                               icon: const Icon(Icons.description),