App.js

import React, { Component, PropTypes } from 'react';
import { render } from 'react-dom';
import bankStore from './bankStore';



class BankApp extends Component {
  handleDeposit() {

    bankStore.dispatch({type:"deposit", amount:   this.refs.amount.value})

    this.refs.amount.value = ""
  }

  handleWithdraw() {

    bankStore.dispatch({type:"withdraw", amount:   this.refs.amount.value})

    this.refs.amount.value = ""
  }

  componentDidMount(){
    bankStore.subscribe(()=>{
      this.forceUpdate();
    })
  }

  render() {
    return (
      <div>
        <header><img src="//www.pro-react.com/logos/redux-bank.svg" width="150" /><br/>Redux Bank</header>
        <br />
        <h1>Your balance is {bankStore.getState()} </h1>
        <div className="atm">
          <input type="text" placeholder="Enter Ammount" ref="amount" />
          <br />
          <button onClick={this.handleWithdraw.bind(this)}>Withdraw</button>
          <button onClick={this.handleDeposit.bind(this)}>Deposit</button>
        </div>
      </div>
    );
  }
}
BankApp.propTypes = {
  balance: PropTypes.number,
  onDeposit: PropTypes.func,
  onWithdraw: PropTypes.func
};

render(

  <BankApp />,
  document.getElementById('root')
);

bankStore.js

import { createStore } from 'redux'

let myReducer = (state = 0, action) => {
  console.log(action)
  switch (action.type) {
    case "deposit":
      return state + Number(action.amount)
    case "withdraw":
      return state - Number(action.amount)
    default:
      return state
  }

}

const bankStore = createStore(myReducer);

export default bankStore;

styles.css

body {
  margin: 0;
  font-family: "Myriad Pro", Helvetica, Arial, sans-serif;
  background-color: #00703B;
  color: #fff;
  text-align: center;
}
header {
  width:100%;
  padding: 15px;
  background-color: #D8D8BF;
  color: #00703B;
  font-size: 30px;
}
h1{
  font-size: 30px;
}
.atm {
  width: 300px;
  height: 115px;
  border-radius: 10px;
  background-color: #1D4F27;
  margin: 10px auto 0 auto;
  padding: 20px;
}
.atm input {
  font-size:25px;
  width: 272px
}
.atm button {
  margin: 20px 10px;
  padding: 20px 40px;
}