React js inline style best practices

Question

I am aware that React classes allow you to provide styles, like in:

const MyDiv = React.createClass({
  render: function() {
    const style = {
      color: 'white',
      fontSize: 200
    };
    
    return <div style={style}> Have a good and productive day! </div>;
  }
});

Should I try to style everything this way and not include any styles in my CSS file?

Or should I absolutely avoid using inline styles?

Combining the two seems strange and unorganized since two places would need to be examined while adjusting styling.