text: import React from 'react';
  import PropTypes from 'prop-types';
  import './Screen.css';
  
  const Screen = ({ value, isError }) => (
    <div className={`screen ${isError ? 'error' : null}`}>{value}</div>
  );
  export default Screen;
  Screen.propTypes = {
    value: PropTypes.string.isRequired,
    isError: PropTypes.bool.isRequired,
  };
  