Flutter Stack positioning and overflow

I am currently working on flutter. I am using stack for stack 2 widgets. But i have some problems.

This is what I am trying to do.

But my widgets look like this.

That's my code:

class UpcomingSessionItem extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Stack(
      clipBehavior: Clip.none,
      alignment: AlignmentDirectional.bottomCenter,
      children: [
        ClipRRect(
            borderRadius: BorderRadius.circular(25),
            child: Image.asset('assets/images/yoga-1.jpg')),
        Container(
          height: 100,
          padding: EdgeInsets.all(20),
          color: Colors.white,
          child: Column(
            children: [
              Row(
                children: [
                  Column(
                    children: [
                      Text(
                        "9 am - 10:30 am",
                        style: TextStyle(fontWeight: FontWeight.bold),
                      ),
                      Text("Yoga for Beginners with Emily Cassel")
                    ],
                  )
                ],
              )
            ],
          ),
        ),
      ],
    );
  }
}

Wrap your Container(Widget) which is inside the stack with the Positioned Widget and set the bottom, left, and right attributes. and you will get the output

You can try this code by copy-paste in your editor.

Example Code here

import 'package:flutter/material.dart';

class StackExample extends StatefulWidget {
  @override
  _StackExampleState createState() => _StackExampleState();
}

class _StackExampleState extends State<StackExample> {
  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return
      Container(
      alignment: Alignment.center,
      padding: EdgeInsets.all(20),
      child: Stack(
        clipBehavior: Clip.none,
        alignment: AlignmentDirectional.bottomCenter,
        children: [
          ClipRRect(borderRadius: BorderRadius.circular(25), child: Image.asset('assets/image.png')),
          Positioned(
            bottom: -50,
            right: 20,
            left: 20,
            child: Container(
              height: 150,
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(15),
                color: Colors.white,
              ),
              padding: EdgeInsets.all(20),
              alignment: Alignment.center,
              child: Column(
                mainAxisSize: MainAxisSize.min,
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  Text(
                    "TITLE",
                    textAlign: TextAlign.center,
                    style: TextStyle(fontWeight: FontWeight.bold, fontSize: 18, decoration: TextDecoration.none, color: Colors.black),
                  ),
                  SizedBox(
                    height: 20,
                  ),
                  Text(
                    "Hey, There?",
                    textAlign: TextAlign.center,
                    style: TextStyle(fontWeight: FontWeight.bold, fontSize: 14, decoration: TextDecoration.none, color: Colors.black),
                  ),
                  SizedBox(
                    height: 20,
                  ),
                  Text(
                    "This is the example",
                    textAlign: TextAlign.center,
                    style: TextStyle(fontSize: 15, decoration: TextDecoration.none, color: Colors.black),
                  )
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}