css errors for

Acedemy

Hi, I have testing page in here

http://sablonlar.camart.us/

when I check css file from here
http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Fsablonlar.camart.us%2F&profile=css3&usermedium=all&warning=1&vextwarning=&lang=el

(you can translate whith google translate that)
there are 51 error
how can we fix that?