How do i get the version of CSS that I am using?
The version is only defined by the CSS selectors, propreties and attributes that you use.
You are free to mix elements of CSS 1, 2 and 3 in any styles that you write.
You can refer to the CSS specifications to see more details. The specifications and drafts at the W3C is available via this index: http://www.w3schools.com/w3c/w3c_css.asp