Awesome font icon and text in the input quote button?


I have a similar problem like here , i want to place font awesome icon into my submit button and also a text, it looks so:

Content of my input submit value is Buy now  

The icon is visible because i set on input field font-family: FontAwesome; my question is, how can i set on my text inside the button standard font family?


<button type="submit" class="btn btn-default">
                    <i class="fa fa-shopping-cart"></i> Buy Now