CSS-Lesson 3

Selectors

CSS selectors include all HTML tags, alone and in combinations. In addition there are author-generated elements and a small number of pseudo elements.

Selector	Use	Examples
universal	use to create a rule applicable to all tags
tag	apply the rule to all instances of the tag	h1 p
multiple tag*	separate tags with a comma	h1,h2,h3
descendent selector	Apply to the second tag if it is nested somewhere within the first tag	p em p.center
parent-child tag	Apply to the second tag if it nested immediately within the first tag	body > p
id*	a single use on any one page	#name tag#name
class*	use for multiple uses on a page	.name tag.name
pseudo-element	e.g. for drop-caps or for putting the first line in small caps	p:first-letter p:first-line
pseudo-class*	used for changing links according to their state	a:hover a:active a:focus a:link a:visited
adjacent tags	apply to the second tag if it is next to the first tag	h1 + h2 p + h3
attribute selector	apply to tags that have the attribute shown in the square brackets	th [colspan]

NOTE

* indicates the most commonly used form of selectors. Others are described in later lessons.

Inheritance

Some property values show an alternative 'inherit'. This implies that the property is not given because the selector inherits that property from a containing selector.

CSS comments

Comments in CSS are shown like this:
/* CSS comment goes here. */