Introduction to CSS

Cascading Style Sheets (CSS):

* specify physical properties (layout) of HTML tags
* are (usually) written in separate files
* can be shared for many HTML documents

There are many advantages:

* logical and physical properties may be separated
* document groups can have consistent looks
* the look can easily be changed

A CSS stylesheet works by:

* allowing more than 50 properties to be defined for each kind of tag;
* the definitions for a tag may depend on its context
* undefined properties are inherited from enclosing tags
* normal HTML corresponds to default values of properties

Using stylesheets, all tags become logical - however, CSS stylesheets only
address superficial properties of documents.