Mindbody Widget adding CSS additions to Booking Schedule Look/Design

Hi I have a client that I added custom CSS code to in Mindbody to adjust the various attributes of the booking calendar widget for an event. However everytime I put the Mindbody code (that supposedly incorprates the CSS code?) I lose the calendar. Anyone, fun into this and a solution and anyone have info on why MB is not partnering with Wix. They seem centered on Square and Wordpress promoting. Thanks