Hi
juancho!
1) While specifying CSS files, you need to make your AView class to have LC_Dependencies() on SportSkin module:
http://kb.x-cart.com/display/XDD/Making+one+module+depend+on+another#Makingonemodul edependonanother-Understandingtheproblem
This way you will make sure that your CSS classes are declared after SportSkin ones.
2) I feel you need to make your custom module depend on the SportSkin module. You can do it according to:
http://kb.x-cart.com/display/XDD/Making+one+module+depend+on+another#Makingonemodul edependonanother-What...toworkproperly
It's optional though.