may already have defined such styles. Assume that a UA has the following styles defined:
UL {list-style-type: disc;}
UL UL {list-style-type: circle;}
UL UL UL {list-style-type: square;}
If this is so, and it's likely that it will be, you will have to declare your own styles to overcome the UA's styles. Inheritance won't be enough in such a case.