CSS pseudo-classes

CSS pseudo-classes are used to add special effects to some selectors.

Syntax

The syntax of pseudo-classes:

selector:pseudo-class {property: value}

CSS classes can also be used with pseudo-classes:

selector.class:pseudo-class {property: value}

Anchor Pseudo-classes

A link that is active, visited, unvisited, or when you mouse over a link can
all be displayed in different ways
in a CSS-supporting browser:

a:link {color: #FF0000}     /* unvisited link */
a:visited {color: #00FF00}  /* visited link */
a:hover {color: #FF00FF}   /* mouse over link */
a:active {color: #0000FF}   /* selected link */

Note: a:hover MUST come after a:link and a:visited in the CSS
definition in order to be effective!!

Note: a:active MUST come after a:hover in the CSS
definition in order to be effective!!

Note: Pseudo-class names are not case-sensitive.

Pseudo-classes and CSS Classes

Pseudo-classes can be combined with CSS classes: 

a.red:visited {color: #FF0000}
<a class="red" href="css_syntax.asp">CSS Syntax</a>

If the link in the example above has been visited, it will be displayed in red.

CSS2 - The :first-child Pseudo-class

The :first-child pseudo-class matches a specified element that is the first child of
another
element.

Note: For :first-child to work in IE a <!DOCTYPE> must be declared.

Match the first <p> element

In the following example, the selector matches any <p> element that is the first child
of any element: 

<html>
<head>

<style type="text/css">
p:first-child
{
color:blue
} 
</style>
</head>
<body>
<p>I am a strong man.</p>
<p>I am a strong man.</p>

</body>
</html>

Try it yourself!

Match the first <i> element in all <p> elements

In the following example, the selector matches the first <i> element in
all

<p> elements:

<html>
<head>
<style type="text/css">
p > i:first-child
{
font-weight:bold
} 
</style>

</head>
<body>
<p>I am a <i>strong</i> man. I am a <i>strong</i> man.</p>

<p>I am a <i>strong</i> man. I am a <i>strong</i> man.</p>
</body>
</html>

Try it yourself!

Match all <i> elements in all first child <p> elements

In the following example, the selector matches all <i> elements in
<p> elements that are the first child of another element:

<html>
<head>
<style type="text/css">
p:first-child i
{
color:blue
} 
</style>
</head>
<body>
<p>I am a <i>strong</i> man. I am a <i>strong</i> man.</p>

<p>I am a <i>strong</i> man. I am a <i>strong</i> man.</p>
</body>
</html>

Try it yourself!

CSS2 - The :lang Pseudo-class

The :lang pseudo-class allows you to define special rules for different
languages. In the example below, the :lang class defines the type of quotation
marks for q elements with a lang attribute with a value of "no":

<html>
<head>
<style type="text/css">

q:lang(no)
{
quotes: "~" "~"
}
</style>
</head>
<body>
<p>Some text <q lang="no">A quote in a paragraph</q>

Some text.</p>
</body>
</html>

Pseudo-classes

Browser support: IE: Internet Explorer, F: Firefox, N: Netscape.

W3C: The number in the "W3C" column indicates in which CSS recommendation
the property is defined (CSS1 or CSS2).

Pseudo-class Purpose IE F N W3C
:active Adds special style to an activated element 4 1 8 1
:focus Adds special style to an element while the element has
focus		 - 1.5 8 2
:hover Adds special style to an element when you mouse over  it 4 1 7 1
:link Adds special style to an unvisited link 3 1 4 1
:visited Adds special style to a visited link 3 1 4 1
:first-child Adds special style to an element that is the first child of some other element 7 1 7 2
:lang Allows the author to specify a language to use in a specified element - 1 8 2