JHotelReservation Forum - Changing character size of reservation Module

I am configuring JHotelPRO and run into a number of incompatibility issues with my current system. I am not satisfied with the layout of the reservation module. Mainly the characters are too large. Where and how can I change this?
The example is on te upper-left side (green box)

Hi Jeroen, 

We can fix the existing css conflicts. 

Please send us your Joomla and FTP login using the ticketing system.