How to add multiple CCS ?

Hey when i go in CSS Style Sheet in colors,to add new one i have to backspace the old one,can i add multiplle CSS codes. ?

What do you mean by multiple css codes? I don't understand.

See i have one CSS code alredy activated,now i want to add another and when i click on CSS stylesheet,the old one is there ,how to add new one ? without deleting the old one.

Just click after last line that should be } and press Enter of the keyboard then add a new code.... See:

Thanks a lot.

Glad I could help you.