As CS is a nicer, more formal restaurant, I am more comfortable dressing according to the location. The service staff is dressed 'formally' in black slacks, white long sleeve shirts and black bow ties. I wear casual slacks and a tropical shirt or polo. I see people there in shorts regularly. Earlier this year there was a guy at the next table wearing a t-shirt and a ball cap during dinner. That really bothered me. As someone else said, the won't turn you away. But that may not be the best measure.