Text is cut horizontally in flutter

The problem is because you define the exact layout portion in the parent layout (column with two flexible widgets) with a given flex.

To fix this you need to:

1. Give the Card widget’s column the mainAxisSize property and set to MainAxisSize.min to make the inner card layout follow its child size automatically (because the default value is MainAxisSize.max).
2. In the parent layout, change Flexible that wraps the Center widget to Expanded, so your Center widget will be filled side-by-side with the Card widget.
3. Remove the Flexible widget that wraps the MyCardWidget to let the MyCardWidget auto-resize by its content.

And this is the modified code below that I marked the changes with comments:

Card Widget

Card(
  color: Get.isDarkMode ? const Color.fromARGB(255, 31, 31, 31) : Theme.of(context).colorScheme.surface,
  child: Column(
    mainAxisSize: MainAxisSize.min // <----- ADD THIS
    children: [
      Padding(
        padding: const EdgeInsets.all(8.0),
        child: Row(
          children: [
            Padding(
              padding: const EdgeInsets.all(8),
              child: CircleAvatar(
                radius: 38,
                backgroundImage: CachedNetworkImageProvider(pr.picLink),
              ),
            ),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(pr.name, style: Theme.of(context).textTheme.bodyLarge!.copyWith(fontWeight: FontWeight.w900)),
                  Text(pr.detail, style: Theme.of(context).textTheme.bodyMedium),
                ],
              ),
            ),
          ],
        ),
      ),

      Flexible(
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Text(
            pr.longDetail ?? "null",
            style: Theme.of(context).textTheme.bodyLarge,
            overflow: TextOverflow.clip,
            textAlign: TextAlign.justify,
            // softWrap: true,
          ),
        ),
      ),
    ],
  ),
);

Parent Layout

Column(
  children: [
    Expanded( // <-----  CHANGE FLEXIBLE TO EXPANDED
      child: Center(
        child: ....
      ),
    ),
    MyCardWidget() // <----- REMOVE FLEXIBLE WIDGET
  ],
),

Result

And this is the result:

The code below is the workaround that I modified from your code to demonstrate the resulting gif above (you can try it on DartPad):

import 'package:flutter/material.dart';

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

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Column(
          children: [
            Expanded(
              child: Center(child: Text('Haha')),
            ),
            MyCardWidget(),
          ],
        ),
      ),
      debugShowCheckedModeBanner: false,
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Card(
      // color: Get.isDarkMode
      color: false
          ? const Color.fromARGB(255, 31, 31, 31)
          : Theme.of(context).colorScheme.surface,
      // color: Colors.white.withOpacity(.2),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Row(
              children: [
                Padding(
                  padding: const EdgeInsets.all(8),
                  child: CircleAvatar(
                    radius: 38,
                    // backgroundImage: CachedNetworkImageProvider(pr.picLink),
                  ),
                ),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text('pr.name',
                          style: Theme.of(context)
                              .textTheme
                              .bodyLarge!
                              .copyWith(fontWeight: FontWeight.w900)),
                      Text('pr.detail',
                          style: Theme.of(context).textTheme.bodyMedium),
                    ],
                  ),
                ),
              ],
            ),
          ),

// HERE
          Flexible(
            child: Padding(
              padding: const EdgeInsets.all(8.0),
              child: Text(
                'test ' * 300 ?? "null",
                style: Theme.of(context).textTheme.bodyLarge,
                overflow: TextOverflow
                    .clip, // Kelimeleri kesmeden taşma durumunda tamamen keser
                textAlign: TextAlign.justify,
                // softWrap: true,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

Hopefully it can solve your problem 😉