The three levels of CSS define so many properties, I can't cover them all here. There are over 120 in level 2 alone. Instead, I'll cover the basic categories you are likely to encounter and leave more exhaustive descriptions to books specializing on the topic.
CSS properties can be passed down from a container element to its child. This inheritance principle greatly simplifies stylesheet design. For example, in the document element rule, you can set a font family that will be used throughout the document. Wherever you want to use a different family, simply insert a new property for a rule and it will override the global setting.
In Figure 5-9, a
para inherits some properties from
section, which in turn inherits
article. The properties
color are defined in the property set for
article, and inherited by both
para. The property
font-size is not inherited by
section's explicit setting overrides it.
para does inherit this property
Figure 5-9. Element-inheriting properties
Inheritance is forbidden for some properties where it wouldn't
make sense to pass that trait on. For example, the
background-image property, which causes an image to be loaded and displayed in the background, is not inherited. If every element did inherit this property, the result would be a complete mess, with every paragraph and ...