Line : 2 (Level : 1) You have no color with your background-color : body 
Line : 6 (Level : 1) You have no background-color with your color : p.content 
Line : 7 font-family: You are encouraged to offer a generic family as a last alternative 
Line : 7 (Level : 2) font-family: You are encouraged to offer a generic family as a last alternative : p.content 
Line : 20 (Level : 1) You have no background-color with your color : p.copyright