Cascade... ??

[VolpeFox]

I have a big page with more than 10 different object-class.
Every object-class has near than 5-10 sub-object-class.

How can I avoid to create classes like "PrincipalClass" and
"PricipalClassSubClassWhenIsBold"... ? ?

Isn't possible to create a CSS file that do somethinglike:

When a "sub-class1" is inside a "Big-Class1" it is black and bold
When a "sub-class1" is inside a "Big-Class2" it is green

Sorry for may english!

Thanks!

Alejandro

[Raja]

#Big-Class1 #sub-class1
{
}

#Big-Class2 #sub-class1
{
}