CSS Syntax

Syntax

The CSS syntax is made up of three parts: a selector, a property and a value:

selector {property: value}

The selector is normally the HTML element/tag you wish to define, the property is the attribute you wish to change, and each property can take a value. The property and value are separated by a colon and surrounded by curly braces:

body {color: black}

If the value is multiple words, put quotes around the value:

p {font-family: "sans serif"}

Note: If you wish to specify more than one property, you must separate each property with a semi-colon. The example below shows how to define a center aligned paragraph, with a red text color:

p {text-align:center;color:red}

To make the style definitions more readable, you can describe one property on each line, like this:

p
{
text-align: center;
color: black;
font-family: arial
}

Grouping

You can group selectors. Separate each selector with a comma. In the example below we have grouped all the header elements. Each header element will be green:

h1,h2,h3,h4,h5,h6 
{
color: green
}

The class Selector

With the class selector you can define different styles for the same type of HTML element. Say that you would like to have two types of paragraphs in your document: one right-aligned paragraph, and one center-aligned paragraph. Here is how you can do it with styles:

p.right {text-align: right}
p.center {text-align: center}

You have to use the class attribute in your HTML document:

<p class="right">
This paragraph will be right-aligned.
</p>

<p class="center">
This paragraph will be center-aligned.
</p>

Note: Only one class attribute can be specified per HTML element! The example below is wrong:

<p class="right" class="center">
This is a paragraph.
</p>

You can also omit the tag name in the selector to define a style that will be used by all HTML elements that have a certain class. In the example below, all HTML elements with class="center" will be center-aligned:

.center {text-align: center}

In the code below both the h1 element and the p element have class="center". This means that both elements will follow the rules in the ".center" selector:

<h1 class="center">
This heading will be center-aligned
</h1>

<p class="center">
This paragraph will also be center-aligned.
</p>

The id Selector

The id selector is different from the class selector! While a class selector may apply to SEVERAL elements on a page, an id selector always applies to only ONE element.

An ID attribute must be unique within the document.

The style rule below will match a p element that has the id value "para1":

p#para1
{
text-align: center;
color: red
}

The style rule below will match the first element that has the id value "wer345":

*#wer345 {color: green}

The rule above will match this h1 element:

<h1 id="wer345">Some text</h1>

The style rule below will match a p element that has the id value "wer345":

p#wer345 {color: green}

The rule above will not match this h2 element:

<h2 id="wer345">Some text</h2>

CSS Comments

You can insert comments in CSS to explain your code, which can help you when you edit the source code at a later date. A comment will be ignored by the browser. A CSS comment begins with "/*", and ends with "*/", like this:

/* This is a comment */
p
{
text-align: center;
/* This is another comment */
color: black;
font-family: arial
}

CSS How To...

Examples

Look at Example 1
Look at Example 2

How to Insert a Style Sheet

When a browser reads a style sheet, it will format the document according to it. There are three ways of inserting a style sheet:

External Style Sheet

An external style sheet is ideal when the style is applied to many pages. With an external style sheet, you can change the look of an entire Web site by changing one file. Each page must link to the style sheet using the <link> tag. The <link> tag goes inside the head section:

<head>
<link rel="stylesheet" type="text/css"
href="mystyle.css" />
</head>

The browser will read the style definitions from the file mystyle.css, and format the document according to it.

An external style sheet can be written in any text editor. The file should not contain any html tags. Your style sheet should be saved with a .css extension. An example of a style sheet file is shown below:

hr {color: sienna}
p {margin-left: 20px}
body {background-image: url("images/back40.gif")}

NOTE: Do NOT leave spaces between the property value and the units! If you use "margin-left: 20 px" instead of "margin-left: 20px" it will only work properly in IE6 but it will not work in Mozilla or Netscape.

Internal Style Sheet

An internal style sheet should be used when a single document has a unique style. You define internal styles in the head section by using the <style> tag, like this:

<head>
<style type="text/css">
hr {color: sienna}
p {margin-left: 20px}
body {background-image: url("images/back40.gif")}
</style>
</head>

The browser will now read the style definitions, and format the document according to it.

Note: A browser normally ignores unknown tags. This means that an old browser that does not support styles, will ignore the <style> tag, but the content of the <style> tag will be displayed on the page. It is possible to prevent an old browser from displaying the content by hiding it in the HTML comment element:

<head>
<style type="text/css">
<!--
hr {color: sienna}
p {margin-left: 20px}
body {background-image: url("images/back40.gif")}
-->
</style>
</head>

Inline Styles

An inline style loses many of the advantages of style sheets by mixing content with presentation. Use this method sparingly, such as when a style is to be applied to a single occurrence of an element.

To use inline styles you use the style attribute in the relevant tag. The style attribute can contain any CSS property. The example shows how to change the color and the left margin of a paragraph:

<p style="FONT-SIZE:10px; 
     COLOR: sienna; margin-left: 20px">
This is a paragraph
</p>

Multiple Style Sheets

If some properties have been set for the same selector in different style sheets, the values will be inherited from the more specific style sheet.

For example, an external style sheet has these properties for the h3 selector:

h3 
{
color: red;
text-align: left;
font-size: 8pt
}

And an internal style sheet has these properties for the h3 selector:

h3 
{
text-align: right; 
font-size: 20pt
}

If the page with the internal style sheet also links to the external style sheet the properties for h3 will be:

color: red; 
text-align: right; 
font-size: 20pt

The color is inherited from the external style sheet and the text-alignment and the font-size is replaced by the internal style sheet.

CSS Background Properties

CSS Background properties define the background effects of an element.

Examples

Set the background color
This example demonstrates how to set the background color for an element.

Set an image as the background
This example demonstrates how to set an image as the background.

How to repeat a background image
This example demonstrates how to repeat a background image only vertically.

How to place the background image
This example demonstrates how to place the image on the page.

How to set a fixed background image
This example demonstrates how to set a fixed background image. The image will not scroll with the rest of the page.

All the background properties in one declaration
This example demonstrates how to use the shorthand property for setting all of the background properties in one declaration.

CSS Background

The Background properties allow you to control the background color of an element, set an image as the background, repeat a background image vertically or horizontally, and position an image on a page.

Background Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
background	A shorthand property for setting all background properties in one declaration	background-color background-image background-repeat background-attachment background-position	6.0	4.0	CSS1
background-attachment	Sets whether a background image is fixed or scrolls with the rest of the page	scroll fixed	6.0	4.0	CSS1
background-color	Sets the background color of an element	color-rgb color-hex color-name transparent	4.0	4.0	CSS1
background-image	Sets an image as the background	url none	4.0	4.0	CSS1
background-position	Sets the starting position of a background image	top left top center top right center left center center center right bottom left bottom center bottom right x-% y-% x-pos y-pos	6.0	4.0	CSS1
background-repeat	Sets if/how a background image will be repeated	repeat repeat-x repeat-y no-repeat	4.0	4.0	CSS1

CSS Text Properties

CSS Text properties define the appearance of text.

Examples

Set the color of the text
This example demonstrates how to set the color of the text.

Set the background-color of the text
This example demonstrates how to set the background-color of a part of the text.

Specify the space between characters
This example demonstrates how to increase or decrease the space between characters.

Align the text
This example demonstrates how to align the text.

Decorate the text
This example demonstrates how to add decoration to text.

Indent text
This example demonstrates how to indent the first line of a paragraph.

Control the letters in a text
This example demonstrates how to control the letters in a text.

CSS Text

Text properties allow you to control the appearance of text. It is possible to change the color of a text, increase or decrease the space between characters in a text, align a text, decorate a text, indent the first line in a text, and more.

Text Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Possible Values	NN	IE	W3C
color	Sets the color of a text	color	4.0	3.0	CSS1
direction	Sets the text direction	ltr rtl			CSS2
letter-spacing	Increase or decrease the space between characters	normal length	6.0	4.0	CSS1
text-align	Aligns the text in an element	left right center justify	4.0	4.0	CSS1
text-decoration	Adds decoration to text	none underline overline line-through blink	4.0	4.0	CSS1
text-indent	Indents the first line of text in an element	length %	4.0	4.0	CSS1
text-shadow		none color length
text-transform	Controls the letters in an element	none capitalize uppercase lowercase	4.0	4.0	CSS1
unicode-bidi		normal embed bidi-override		5.0	CSS2
white-space	Sets how white space inside an element is handled	normal pre nowrap	4.0	5.5	CSS1
word-spacing	Increase or decrease the space between words	normal length	6.0	6.0	CSS1

CSS Font Properties

CSS Font properties define the font in text.

Examples

Set the font of a text
This example demonstrates how to set a font of a text.

Set the size of the font
This example demonstrates how to set the size of a font.

Set the style of the font
This example demonstrates how to set the style of a font.

Set the variant of the font
This example demonstrates how to set the variant of a font.

Set the boldness of the font
This example demonstrates how to set the boldness of a font.

All the font properties in one declaration
This example demonstrates how to use the shorthand property for setting all of the font properties in one declaration.

CSS Fonts

The Font properties allow you to change the font family, boldness, size, and the style of a text.

Notes - Useful Tips

Fonts are identified by their name in CSS1. Note that if a browser does not support the font that is specified, it will use a default font.

Font Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
font	A shorthand property for setting all of the properties for a font in one declaration	font-style font-variant font-weight font-size/line-height font-family caption icon menu message-box small-caption status-bar	4.0	4.0	CSS1
font-family	A prioritized list of font family names and/or generic family names for an element	family-name generic-family	4.0	3.0	CSS1
font-size	Sets the size of a font	xx-small x-small small medium large x-large xx-large smaller larger length %	4.0	3.0	CSS1
font-size-adjust	Specifies an aspect value for an element that will preserve the x-height of the first-choice font	none number			CSS2
font-stretch	Condenses or expands the current font-family	normal wider narrower ultra-condensed extra-condensed condensed semi-condensed semi-expanded expanded extra-expanded ultra-expanded			CSS2
font-style	Sets the style of the font	normal italic oblique	4.0	4.0	CSS1
font-variant	Displays text in a small-caps font or a normal font	normal small-caps	6.0	4.0	CSS1
font-weight	Sets the weight of a font	normal bold bolder lighter 100 200 300 400 500 600 700 800 900	4.0	4.0	CSS1

CSS Border Properties

CSS Border properties define the borders around an element.

Examples

Set the style of the four borders
This example demonstrates how to set the style of the four borders.

Set different borders on each side
This example demonstrates how to set different borders on each side of the element.

Set the color of the four borders
This example demonstrates how to set the color of the four borders. It can have from one to four colors.

Set the width of the bottom border
This example demonstrates how to set the width of the bottom border.

Set the width of the left border
This example demonstrates how to set the width of the left border.

Set the width of the right border
This example demonstrates how to set the width of the right border.

Set the width of the top border
This example demonstrates how to set the width of the top border.

All the bottom border properties in one declaration
This example demonstrates a shorthand property for setting all of the properties for the bottom border in one declaration.

All the left border properties in one declaration
This example demonstrates a shorthand property for setting all of the properties for the left border in one declaration.

All the right border properties in one declaration
This example demonstrates a shorthand property for setting all of the properties for the right border in one declaration.

All the top border properties in one declaration
This example demonstrates a shorthand property for setting all of the properties for the top border in one declaration.

All the width of the border properties in one declaration
This example demonstrates a shorthand property for setting the width of the four borders in one declaration, can have from one to four values.

All the border properties in one declaration
This example demonstrates a shorthand property for setting all of the properties for the four borders in one declaration, can have from one to three values.

CSS Borders

The Border properties allow you to specify the style, color, and width of an element's border. In HTML we use tables to create borders around a text, but with the CSS Border properties we can create borders with nice effects, and it can be applied to any element.

Border Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
border	A shorthand property for setting all of the properties for the four borders in one declaration	border-width border-style border-color	4.0	4.0	CSS1
border-bottom	A shorthand property for setting all of the properties for the bottom border in one declaration	border-bottom-width border-style border-color	6.0	4.0	CSS1
border-bottom-color	Sets the color of the bottom border	border-color	6.0	4.0	CSS2
border-bottom-style	Sets the style of the bottom border	border-style	6.0	4.0	CSS2
border-bottom-width	Sets the width of the bottom border	thin medium thick length	4.0	4.0	CSS1
border-color	Sets the color of the four borders, can have from one to four colors	color	6.0	4.0	CSS1
border-left	A shorthand property for setting all of the properties for the left border in one declaration	border-left-width border-style border-color	6.0	4.0	CSS1
border-left-color	Sets the color of the left border	border-color	6.0	4.0	CSS2
border-left-style	Sets the style of the left border	border-style	6.0	4.0	CSS2
border-left-width	Sets the width of the left border	thin medium thick length	4.0	4.0	CSS1
border-right	A shorthand property for setting all of the properties for the right border in one declaration	border-right-width border-style border-color	6.0	4.0	CSS1
border-right-color	Sets the color of the right border	border-color	6.0	4.0	CSS2
border-right-style	Sets the style of the right border	border-style	6.0	4.0	CSS2
border-right-width	Sets the width of the right border	thin medium thick length	4.0	4.0	CSS1
border-style	Sets the style of the four borders, can have from one to four styles	none hidden dotted dashed solid double groove ridge inset outset	6.0	4.0	CSS1
border-top	A shorthand property for setting all of the properties for the top border in one declaration	border-top-width border-style border-color	6.0	4.0	CSS1
border-top-color	Sets the color of the top border	border-color	6.0	4.0	CSS2
border-top-style	Sets the style of the top border	border-style	6.0	4.0	CSS2
border-top-width	Sets the width of the top border	thin medium thick length	4.0	4.0	CSS1
border-width	A shorthand property for setting the width of the four borders in one declaration, can have from one to four values	thin medium thick length	4.0	4.0	CSS1

CSS Margin Properties

CSS Margin properties define the space around elements.

Examples

Set the left margin of a text
This example demonstrates how to set the left margin of a text.

Set the right margin of a text
This example demonstrates how to set the right margin of a text.

Set the top margin of a text
This example demonstrates how to set the top margin of a text.

Set the bottom margin of a text
This example demonstrates how to set the bottom margin of a text.

All the margin properties in one declaration
This example demonstrates how to set a shorthand property for setting all of the margin properties in one declaration.

CSS Margins

The Margin properties define the space around elements. It is possible to use negative values to overlap content. The top, right, bottom, and left margin can be changed independently using separate properties. A shorthand margin property can also be used to change all of the margins at once.

Browser Note: Netscape and IE give the body tag a default margin of 8px. Opera does not! Instead, Opera applies a default padding of 8px, so if one wants to adjust the margin for an entire page and have it display correctly in Opera, the body padding must be set as well!

Margin Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
margin	A shorthand property for setting the margin properties in one declaration	margin-top margin-right margin-bottom margin-left	4.0	4.0	CSS1
margin-bottom	Sets the bottom margin of an element	auto length %	4.0	4.0	CSS1
margin-left	Sets the left margin of an element	auto length %	4.0	3.0	CSS1
margin-right	Sets the right margin of an element	auto length %	4.0	3.0	CSS1
margin-top	Sets the top margin of an element	auto length %	4.0	3.0	CSS1

CSS Padding Properties

CSS Padding properties define the space between the element border and the element content.

Examples

Set the left padding
This example demonstrates how to set the left padding of a tablecell.

Set the right padding
This example demonstrates how to set the right padding of a tablecell.

Set the top padding
This example demonstrates how to set the top padding of a tablecell.

Set the bottom padding
This example demonstrates how to set the bottom padding of a tablecell.

All the padding properties in one declaration
This example demonstrates a shorthand property for setting all of the padding properties in one declaration, can have from one to four values.

CSS Padding

The Padding properties define the space between the element border and the element content. Negative values are not allowed. The top, right, bottom, and left padding can be changed independently using separate properties. A shorthand padding property is also created to control multiple sides at once.

Padding Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
padding	A shorthand property for setting all of the padding properties in one declaration	padding-top padding-right padding-bottom padding-left	4.0	4.0	CSS1
padding-bottom	Sets the bottom padding of an element	length %	4.0	4.0	CSS1
padding-left	Sets the left padding of an element	length %	4.0	4.0	CSS1
padding-right	Sets the right padding of an element	length %	4.0	4.0	CSS1
padding-top	Sets the top padding of an element	length %	4.0	4.0	CSS1

CSS List Properties

The List properties allow you to change between different list-item markers, set an image as a list-item marker, and set where to place a list-item marker.

Examples

The different list-item markers in unordered lists
This example demonstrates the different list-item markers in CSS.

The different list-item markers in ordered lists
This example demonstrates the different list-item markers in CSS.

Set an image as the list-item marker
This example demonstrates how to set an image as the list-item marker.

Place the list-item marker
This example demonstrates where to place the list-item marker.

All list properties in one declaration
This example demonstrates a shorthand property for setting all of the properties for a list in one declaration.

List Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
list-style	A shorthand property for setting all of the properties for a list in one declaration	list-style-type list-style-position list-style-image	6.0	4.0	CSS1
list-style-image	Sets an image as the list-item marker	none url	6.0	4.0	CSS1
list-style-position	Places the list-item marker in the list	inside outside	6.0	4.0	CSS1
list-style-type	Sets the type of the list-item marker	none disc circle square decimal decimal-leading-zero lower-roman upper-roman lower-alpha upper-alpha lower-greek lower-latin upper-latin hebrew armenian georgian cjk-ideographic hiragana katakana hiragana-iroha katakana-iroha	4.0	4.0	CSS1
marker-offset		auto length			CSS2

CSS Dimension Properties

The Dimension properties allow you to control the height and width of an element. It also allows you to increase the space between two lines.

Examples

Set the height and width of an image
This example demonstrates how to set the height and width of an image.

Increase the space between lines
This example demonstrates how to increase the space between the lines.

Dimension Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
height	Sets the height of an element	auto length %	6.0	4.0	CSS1
line-height	Sets the distance between lines	normal number length %	4.0	4.0	CSS1
max-height	Sets the maximum height of an element	none length %			CSS2
max-width	Sets the maximum width of an element	none length %			CSS2
min-height	Sets the minimum height of an element	length %			CSS2
min-width	Sets the minimum width of an element	length %			CSS2
width	Sets the width of an element	auto % length	4.0	4.0	CSS1

CSS Classification Properties

The Classification properties allow you to control how to display an element, set where an image will appear in another element, position an element relative to its normal position, position an element using an absolute value, and how to control the visibility of an element.

Examples

How to display an element
This example demonstrates how to display an element.

A simple use of the float property
Let an image float to the right in a paragraph.

An image with border and margins that floats to the right in a paragraph
Let an image float to the right in a paragraph. Add border and margins to the image.

An image with a caption that floats to the right
Let an image with a caption float to the right.

Let the first letter of a paragraph float to the left
Let the first letter of a paragraph float to the left and style the letter.

Creating a horizontal menu
Use float with a list of hyperlinks to create a horizontal menu.

Creating a homepage without tables
Use float to create a homepage with a header, footer, left content and main content.

Position:relative
This example demonstrates how to position an element relative to its normal position.

Position:absolute
This example demonstrates how to position an element using an absolute value.

How to make an element invisible
This example demonstrates how to make an element invisible. Do you want the element to show or not?

Change the cursor
This example demonstrates how to change the cursor.

Classification Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
clear	Sets the sides of an element where other floating elements are not allowed	left right both none	4.0	4.0	CSS1
cursor	Specifies the type of cursor to be displayed	url auto crosshair default pointer move e-resize ne-resize nw-resize n-resize se-resize sw-resize s-resize w-resize text wait help	6.0	4.0	CSS2
display	Sets how/if an element is displayed	none inline block list-item run-in compact marker table inline-table table-row-group table-header-group table-footer-group table-row table-column-group table-column table-cell table-caption	4.0	4.0	CSS1
float	Sets where an image or a text will appear in another element	left right none	4.0	4.0	CSS1
position	Places an element in a static, relative, absolute or fixed position	static relative absolute fixed	4.0	4.0	CSS2
visibility	Sets if an element should be visible or invisible	visible hidden collapse	6.0	4.0	CSS2

CSS Positioning Properties

CSS Positioning properties define the position of an element.

Examples

Set the shape of an element
This example demonstrates how to set the shape of an element. The element is clipped into this shape, and displayed.

Set the left and top position of an element
This example demonstrates how to set the left and top position of an element.

Set the right and bottom position of an element
This example demonstrates how to set the right and bottom position of an element.

Overflow
This example demonstrates how to set the overflow property to specify what should happen when an element's content is too big to fit in a specified area.

Vertical align an image
This example demonstrates how to vertical align an image in a text.

Z-index
Z-index can be used to place an element "behind" another element, using Z-index priority.

Z-index
Check that the elements now have changed their Z-index priority.

CSS Positioning

The Positioning properties allow you to specify the left, right, top, and bottom position of an element. It also allows you to set the shape of an element, place an element behind another, and to specify what should happen when an element's content is too big to fit in a specified area.

Positioning Properties:

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	NN	IE	W3C
bottom	Specifies the bottom edge of an element	auto % length	6.0	5.0	CSS2
clip	Sets the shape of an element. The element is clipped into this shape, and displayed	shape auto	6.0	4.0	CSS2
left	Specifies the left edge of an element	auto % length	4.0	4.0	CSS2
overflow	Sets what happens if the content of an element overflow its area	visible hidden scroll auto	6.0	4.0	CSS2
position	Places an element in a static, relative, absolute or fixed position	static relative absolute fixed	4.0	4.0	CSS2
right	Specifies the right edge of an element	auto % length		5.0	CSS2
top	Sets how far the top edge of an element is above/below the top edge of the parent element	auto % length	4.0	4.0	CSS2
vertical-align	Sets the vertical alignment of an element	baseline sub super top text-top middle bottom text-bottom length %	4.0	4.0	CSS1
z-index	Sets the stack order of an element	auto number	6.0	4.0	CSS2

CSS Pseudo-classes

Pseudo-classes are used in CSS to add different effects to some selectors, or to a part of some selectors.

Examples

Hyperlink
This example demonstrates how to add different colors to a hyperlink in a document.

Hyperlink 2
This example demonstrates how to add other styles to hyperlinks.

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.

Note: IE 4 and higher supports the anchor pseudo-class. NN 4.5 and Netscape 6 support the anchor pseudo-class only partially.

Pseudo-classes and CSS Classes

Pseudo-classes can be combined with CSS classes:

a.red:visited {color: #FF0000}

<a class="red" href="example.htm">Example</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.

In this example, the selector matches any p element that is the first child of a div element, and indents the first paragraph inside a div element:

div > p:first-child
{
text-indent:25px
}

This selector will match the first paragraph inside the div in the following HTML:

<div>
<p>
First paragraph in div.
This paragraph will be indented.
</p>
<p>
Second paragraph in div.
This paragraph will not be indented.
</p>
</div>

but it will not match the paragraph in this HTML:

<div>
<h1>Header</h1>
<p>
The first paragraph inside the div.
This paragraph will not be indented.
</p>
</div>

In this example, the selector matches any em element that is the first child of a p element, and sets the font-weight to bold for the first em inside a p element:

p:first-child em
{
font-weight:bold
}

For example, the em in the HTML below is the first child of the paragraph:

<p>I am a <em>strong</em> man.</p>

In this example, the selector matches any a element that is the first child of any element, and sets the text-decoration to none:

a:first-child
{
text-decoration:none
}

For example, the first a in the HTML below is the first child of the paragraph and will not be underlined. But the second a in the paragraph is not the first child of the paragraph and will be underlined:

<p>
Visit <a href="http://www.example.com">example</a>
and learn CSS!
Visit <a href="http://www.example.com">example</a>
and learn HTML!
</p>

CSS2 - The :lang Pseudo-class

The :lang pseudo-class allows the author to specify a language to use in a document or to use in a specified element.

In the example below, the rule sets the type of quotation marks for an HTML document that is in Norwegian:

html:lang(no)
{
quotes: '� ' ' �'
}

In the next example, the rule sets the type of quotation marks for blockquote elements:

blockquote:lang(no)
{
quotes: '� ' ' �'
}

Pseudo-classes

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Pseudo-classes	NN	IE	W3C	Purpose
active		4.0	CSS1	Adds special style to a selected link
hover	7.1	4.0	CSS1	Adds special style to a link when you mouse over it
link	4.0	3.0	CSS1	Adds special style to an unvisited link
visited	4.0	3.0	CSS1	Adds special style to a visited link
:first-child	7.0		CSS2	Adds special style to an element that is the first child of some other element
:lang			CSS2	Allows the author to specify a language to use in a specified element

CSS Pseudo-elements

Pseudo-elements are used in CSS to add different effects to some selectors, or to a part of some selectors.

Examples

Make the first letter special
This example demonstrates how to add special style to the first letter in a text.

Make the first line special
This example demonstrates how to add special style to the first line in a text.

Syntax

The syntax of pseudo-elements:

selector:pseudo-element {property: value}

CSS classes can also be used with pseudo-elements:

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

The :first-line Pseudo-element

The "first-line" pseudo-element is used to add special styles to the first line of the text in a selector:

p {font-size: 12pt}
p:first-line {color: #0000FF; 
                  font-variant: small-caps}

<p>Two or more lines of text</p>

The output could be something like this:

Some text that ends
up on two or more lines

In the example above the browser displays the first line formatted according to the "first-line" pseudo element. Where the browser breaks the line depends on the size of the browser window.

Note: The "first-line" pseudo-element can only be used with block-level elements.

Note: The following properties apply to the "first-line" pseudo-element:

font properties
color properties
background properties
word-spacing
letter-spacing
text-decoration
vertical-align
text-transform
line-height
clear

Note: IE 4.01 and IE 5.0 do not support the "first-line" pseudo-element, but IE 5.5 does.

Note: NN 4.5 does not support the "first-line" pseudo-element.

The :first-letter Pseudo-element

The "first-letter" pseudo-element is used to add special style to the first letter of the text in a selector:

p {font-size: 12pt}
p:first-letter {font-size: 200%; float: left}

<p>The first words of an article.</p>

The output could be something like this:

___
| he first
| words of an
article.

Note: The "first-letter" pseudo-element can only be used with block-level elements.

Note: The following properties apply to the "first-letter" pseudo- element:

font properties
color properties
background properties
margin properties
padding properties
border properties
text-decoration
vertical-align (only if 'float' is 'none')
text-transform
line-height
float
clear

Note: IE 4.01 and IE 5.0 do not support the "first-letter" pseudo-element, but IE 5.5 does.

Note: NN 4.5 does not support the "first-letter" pseudo-element.

Pseudo-elements and CSS Classes

Pseudo-elements can be combined with CSS classes:

p.article:first-letter {color: #FF0000}

<p class="article">A paragraph in an article</p>

The example above will make the first letter of all paragraphs with class="article" red.

Multiple Pseudo-elements

Several pseudo-elements can be combined:

p {font-size: 12pt}
p:first-letter {color: #FF0000; font-size: 200%}
p:first-line {color: #0000FF}

<p>The first words of an article</p>

The output could be something like this:

___
| he first
| words of an
article.

In the example above the first letter of the paragraph will be red with a font size of 24pt. The rest of the first line would be blue while the rest of the paragraph would be the default color.

CSS2 - The :before Pseudo-element

The ":before" pseudo-element can be used to insert some content before an element.

The style below will play a sound before each occurrence of a header one element.

h1:before
{
content: url(beep.wav)
}

CSS2 - The :after Pseudo-element

The ":after" pseudo-element can be used to insert some content after an element.

The style below will play a sound after each occurrence of a header one element.

h1:after
{
content: url(beep.wav)
}

Pseudo-elements

NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Pseudo-elements	IE	W3C	Purpose
first-letter	5.5	CSS1	Adds special style to the first letter of a text
first-line	5.5	CSS1	Adds special style to the first line of a text
:before		CSS2	Inserts some content before an element
:after		CSS2	Inserts some content after an element

CSS2 Media Types

Media Types allow you to specify how documents will be presented in different media. The document can be displayed differently on the screen, on the paper, with an aural browser, etc.

Media Types

Some CSS properties are only designed for a certain media. For example the "voice-family" property is designed for aural user agents. Some other properties can be used for different media types. For example, the "font-size" property can be used for both screen and print media, but perhaps with different values. A document usually needs a larger font-size on a screen than on paper, and sans-serif fonts are easier to read on the screen, while serif fonts are easier to read on paper.

The @media Rule

The @media rule allows different style rules for different media in the same style sheet.

The style in the example below tells the browser to display a 14 pixels Verdana font on the screen. But if the page is printed, it will be in a 10 pixels Times font. Notice that the font-weight is set to bold, both on screen and on paper:

<html>
<head>
<style>
@media screen
{
p.test {font-family:verdana,sans-serif; 
           font-size:14px}
}

@media print
{
p.test {font-family:times,serif; font-size:10px}
}

@media screen,print
{
p.test {font-weight:bold}
}
</style>
</head>

<body>

....

</body>
</html>

See it yourself ! If you use IE 5.0 (or higher) and print this page, you will see that the paragraph under "Media Types" will be displayed in another font, and have a smaller font size than the rest of the text.

Different Media Types

Note: The media type names are not case-sensitive.

Media Type	Description	IE
all	Used for all media type devices	4.0
aural	Used for speech and sound synthesizers
braille	Used for braille tactile feedback devices
embossed	Used for paged braille printers
handheld	Used for small or handheld devices
print	Used for printers	4.0
projection	Used for projected presentations, like slides
screen	Used for computer screens	4.0
tty	Used for media using a fixed-pitch character grid, like teletypes and terminals
tv	Used for television-type devices

CSS2 Reference

The links in the "Property" column point to more useful information about the specific property.

Browser support: NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Background

On-line examples

Property	Description	Values	NN	IE	W3C
background	A shorthand property for setting all background properties in one declaration	background-color background-image background-repeat background-attachment background-position	6.0	4.0	CSS1
background-attachment	Sets whether a background image is fixed or scrolls with the rest of the page	scroll fixed	6.0	4.0	CSS1
background-color	Sets the background color of an element	color-rgb color-hex color-name transparent	4.0	4.0	CSS1
background-image	Sets an image as the background	url none	4.0	4.0	CSS1
background-position	Sets the starting position of a background image	top left top center top right center left center center center right bottom left bottom center bottom right x-% y-% x-pos y-pos	6.0	4.0	CSS1
background-repeat	Sets if/how a background image will be repeated	repeat repeat-x repeat-y no-repeat	4.0	4.0	CSS1

Border

On-line examples

Property	Description	Values	NN	IE	W3C
border	A shorthand property for setting all of the properties for the four borders in one declaration	border-width border-style border-color	4.0	4.0	CSS1
border-bottom	A shorthand property for setting all of the properties for the bottom border in one declaration	border-bottom-width border-style border-color	6.0	4.0	CSS1
border-bottom-color	Sets the color of the bottom border	border-color	6.0	4.0	CSS2
border-bottom-style	Sets the style of the bottom border	border-style	6.0	4.0	CSS2
border-bottom-width	Sets the width of the bottom border	thin medium thick length	4.0	4.0	CSS1
border-color	Sets the color of the four borders, can have from one to four colors	color	6.0	4.0	CSS1
border-left	A shorthand property for setting all of the properties for the left border in one declaration	border-left-width border-style border-color	6.0	4.0	CSS1
border-left-color	Sets the color of the left border	border-color	6.0	4.0	CSS2
border-left-style	Sets the style of the left border	border-style	6.0	4.0	CSS2
border-left-width	Sets the width of the left border	thin medium thick length	4.0	4.0	CSS1
border-right	A shorthand property for setting all of the properties for the right border in one declaration	border-right-width border-style border-color	6.0	4.0	CSS1
border-right-color	Sets the color of the right border	border-color	6.0	4.0	CSS2
border-right-style	Sets the style of the right border	border-style	6.0	4.0	CSS2
border-right-width	Sets the width of the right border	thin medium thick length	4.0	4.0	CSS1
border-style	Sets the style of the four borders, can have from one to four styles	none hidden dotted dashed solid double groove ridge inset outset	6.0	4.0	CSS1
border-top	A shorthand property for setting all of the properties for the top border in one declaration	border-top-width border-style border-color	6.0	4.0	CSS1
border-top-color	Sets the color of the top border	border-color	6.0	4.0	CSS2
border-top-style	Sets the style of the top border	border-style	6.0	4.0	CSS2
border-top-width	Sets the width of the top border	thin medium thick length	4.0	4.0	CSS1
border-width	A shorthand property for setting the width of the four borders in one declaration, can have from one to four values	thin medium thick length	4.0	4.0	CSS1

Classification

On-line examples

Property	Description	Values	NN	IE	W3C
clear	Sets the sides of an element where other floating elements are not allowed	left right both none	4.0	4.0	CSS1
cursor	Specifies the type of cursor to be displayed	url auto crosshair default pointer move e-resize ne-resize nw-resize n-resize se-resize sw-resize s-resize w-resize text wait help	6.0	4.0	CSS2
display	Sets how/if an element is displayed	none inline block list-item run-in compact marker table inline-table table-row-group table-header-group table-footer-group table-row table-column-group table-column table-cell table-caption	4.0	4.0	CSS1
float	Sets where an image or a text will appear in another element	left right none	4.0	4.0	CSS1
position	Places an element in a static, relative, absolute or fixed position	static relative absolute fixed	4.0	4.0	CSS2
visibility	Sets if an element should be visible or invisible	visible hidden collapse	6.0	4.0	CSS2

Dimension

On-line examples

Property	Description	Values	NN	IE	W3C
height	Sets the height of an element	auto length %	6.0	4.0	CSS1
line-height	Sets the distance between lines	normal number length %	4.0	4.0	CSS1
max-height	Sets the maximum height of an element	none length %	6.0		CSS2
max-width	Sets the maximum width of an element	none length %	6.0		CSS2
min-height	Sets the minimum height of an element	length %	6.0		CSS2
min-width	Sets the minimum width of an element	length %	6.0		CSS2
width	Sets the width of an element	auto % length	4.0	4.0	CSS1

Font

On-line examples

Property	Description	Values	NN	IE	W3C
font	A shorthand property for setting all of the properties for a font in one declaration	font-style font-variant font-weight font-size/line-height font-family caption icon menu message-box small-caption status-bar	4.0	4.0	CSS1
font-family	A prioritized list of font family names and/or generic family names for an element	family-name generic-family	4.0	3.0	CSS1
font-size	Sets the size of a font	xx-small x-small small medium large x-large xx-large smaller larger length %	4.0	3.0	CSS1
font-size-adjust	Specifies an aspect value for an element that will preserve the x-height of the first-choice font	none number			CSS2
font-stretch	Condenses or expands the current font-family	normal wider narrower ultra-condensed extra-condensed condensed semi-condensed semi-expanded expanded extra-expanded ultra-expanded			CSS2
font-style	Sets the style of the font	normal italic oblique	4.0	4.0	CSS1
font-variant	Displays text in a small-caps font or a normal font	normal small-caps	6.0	4.0	CSS1
font-weight	Sets the weight of a font	normal bold bolder lighter 100 200 300 400 500 600 700 800 900	4.0	4.0	CSS1

Generated Content

Property	Description	Values	NN	W3C
content	Generates content in a document. Used with the :before and :after pseudo-elements	string url counter(name) counter(name, list-style-type) counters(name, string) counters(name, string, list-style-type) attr(X) open-quote close-quote no-open-quote no-close-quote	6.0	CSS2
counter-increment	Sets how much the counter increments on each occurrence of a selector	none identifier number		CSS2
counter-reset	Sets the value the counter is set to on each occurrence of a selector	none identifier number		CSS2
quotes	Sets the type of quotation marks	none string string	6.0	CSS2

List and Marker

On-line examples

Property	Description	Values	NN	IE	W3C
list-style	A shorthand property for setting all of the properties for a list in one declaration	list-style-type list-style-position list-style-image	6.0	4.0	CSS1
list-style-image	Sets an image as the list-item marker	none url	6.0	4.0	CSS1
list-style-position	Sets where the list-item marker is placed in the list	inside outside	6.0	4.0	CSS1
list-style-type	Sets the type of the list-item marker	none disc circle square decimal decimal-leading-zero lower-roman upper-roman lower-alpha upper-alpha lower-greek lower-latin upper-latin hebrew armenian georgian cjk-ideographic hiragana katakana hiragana-iroha katakana-iroha	4.0	4.0	CSS1
marker-offset		auto length	7.0		CSS2

Margin

On-line examples

Property	Description	Values	NN	IE	W3C
margin	A shorthand property for setting the margin properties in one declaration	margin-top margin-right margin-bottom margin-left	4.0	4.0	CSS1
margin-bottom	Sets the bottom margin of an element	auto length %	4.0	4.0	CSS1
margin-left	Sets the left margin of an element	auto length %	4.0	3.0	CSS1
margin-right	Sets the right margin of an element	auto length %	4.0	3.0	CSS1
margin-top	Sets the top margin of an element	auto length %	4.0	3.0	CSS1

Outlines

Property	Description	Values	W3C
outline	A shorthand property for setting all the outline properties in one declaration	outline-color outline-style outline-width	CSS2
outline-color	Sets the color of the outline around an element	color invert	CSS2
outline-style	Sets the style of the outline around an element	none dotted dashed solid double groove ridge inset outset	CSS2
outline-width	Sets the width of the outline around an element	thin medium thick length	CSS2

Padding

On-line examples

Property	Description	Values	NN	IE	W3C
padding	A shorthand property for setting all of the padding properties in one declaration	padding-top padding-right padding-bottom padding-left	4.0	4.0	CSS1
padding-bottom	Sets the bottom padding of an element	length %	4.0	4.0	CSS1
padding-left	Sets the left padding of an element	length %	4.0	4.0	CSS1
padding-right	Sets the right padding of an element	length %	4.0	4.0	CSS1
padding-top	Sets the top padding of an element	length %	4.0	4.0	CSS1

Positioning

On-line examples

Property	Description	Values	NN	IE	W3C
bottom	Sets how far the bottom edge of an element is above/below the bottom edge of the parent element	auto % length	6.0	5.0	CSS2
clip	Sets the shape of an element. The element is clipped into this shape, and displayed	shape auto	6.0	4.0	CSS2
left	Sets how far the left edge of an element is to the right/left of the left edge of the parent element	auto % length	4.0	4.0	CSS2
overflow	Sets what happens if the content of an element overflow its area	visible hidden scroll auto	6.0	4.0	CSS2
right	Sets how far the right edge of an element is to the left/right of the right edge of the parent element	auto % length	6.0	5.5	CSS2
top	Sets how far the top edge of an element is above/below the top edge of the parent element	auto % length	4.0	4.0	CSS2
vertical-align	Sets the vertical alignment of an element	baseline sub super top text-top middle bottom text-bottom length %	4.0	4.0	CSS1
z-index	Sets the stack order of an element	auto number	6.0	4.0	CSS2

Table

Property	Description	Values	NN	IE	W3C
border-collapse	Sets the border model of a table	collapse separate	7.0	5.5	CSS2
border-spacing	Sets the distance between the borders of adjacent cells (only for the "separated borders" model)	length length	6.0		CSS2
caption-side	Sets the position of the caption according to the table	top bottom left right	6.0		CSS2
empty-cells	Sets whether cells with no visible content should have borders or not (only for the "separated borders" model)	show hide	6.0		CSS2
table-layout	Sets the algorithm used to lay out the table	auto fixed	6.0	5.5	CSS2

Text

On-line examples

Property	Description	Possible Values	NN	IE	W3C
color	Sets the color of a text	color	4.0	3.0	CSS1
direction	Sets the text direction	ltr rtl			CSS2
letter-spacing	Increase or decrease the space between characters	normal length	6.0	4.0	CSS1
text-align	Aligns the text in an element	left right center justify	4.0	4.0	CSS1
text-decoration	Adds decoration to text	none underline overline line-through blink	4.0	4.0	CSS1
text-indent	Indents the first line of text in an element	length %	4.0	4.0	CSS1
text-shadow		none color length
text-transform	Controls the letters in an element	none capitalize uppercase lowercase	4.0	4.0	CSS1
unicode-bidi		normal embed bidi-override		5.0	CSS2
white-space	Sets how white space inside an element is handled	normal pre nowrap	4.0	5.5	CSS1
word-spacing	Increase or decrease the space between words	normal length	6.0	6.0	CSS1

CSS2 Print Reference

Print Properties

Printing HTML documents has always been problematic. In CSS2 the print properties are added to make it easier to print from the Web.

The links in the "Property" column point to more useful information about the specific property.

Browser support: NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	IE	W3C
orphans	Sets the minimum number of lines for a paragraph that must be left at the bottom of a page	number		CSS2
marks	Sets what sort of marks should be rendered outside the page box	none crop cross
page	Sets a page type to use when displaying an element	auto identifier		CSS2
page-break-after	Sets the page-breaking behavior after an element	auto always avoid left right	4.0	CSS2
page-break-before	Sets the page-breaking behavior before an element	auto always avoid left right	4.0	CSS2
page-break-inside	Sets the page-breaking behavior inside an element	auto avoid		CSS2
size	Sets the orientation and size of a page	auto portrait landscape
widows	Sets the minimum number of lines for a paragraph that must be left at the top of a page	number		CSS2

CSS2 Aural Reference

Aural Style Sheets

Aural style sheets use a combination of speech synthesis and sound effects to make the user listen to information, instead of reading information.

Aural presentation can be used:

by blind people
to help users learning to read
to help users who have reading problems
for home entertainment
in the car
by print-impaired communities

The aural presentation converts the document to plain text and feed this to a screen reader (a program that reads all the characters on the screen).

An example of an Aural style sheet:

h1, h2, h3, h4
{
voice-family: male;
richness: 80;
cue-before: url("beep.au")
}

The example above will make the speech synthesizer play a sound, then speak the headers in a very rich male voice.

CSS2 Aural Reference

The links in the "Property" column point to more useful information about the specific property.

Browser support: NN: Netscape, IE: Internet Explorer, W3C: Web Standard

Property	Description	Values	W3C
azimuth	Sets where the sound/voices should come from (horizontally)	angle left-side far-left left center-left center center-right right far-right right-side behind leftwards rightwards	CSS2
cue	A shorthand property for setting the cue-before and cue-after properties in one declaration	cue-before cue-after	CSS2
cue-after	Specifies a sound to be played after speaking an element's content to delimit it from other	none url	CSS2
cue-before	Specifies a sound to be played before speaking an element's content to delimit it from other	none url	CSS2
elevation	Sets where the sound/voices should come from (vertically)	angle below level above higher lower	CSS2
pause	A shorthand property for setting the pause-before and pause-after properties in one declaration	pause-before pause-after	CSS2
pause-after	Specifies a pause after speaking an element's content	time %	CSS2
pause-before	Specifies a pause before speaking an element's content	time %	CSS2
pitch	Specifies the speaking voice	frequency x-low low medium high x-high	CSS2
pitch-range	Specifies the variation in the speaking voice. (Monotone voice or animated voice?)	number	CSS2
play-during	Specifies a sound to be played while speaking an element's content	auto none url mix repeat	CSS2
richness	Specifies the richness in the speaking voice. (Rich voice or thin voice?)	number	CSS2
speak	Specifies whether content will render aurally	normal none spell-out	CSS2
speak-header	Specifies how to handle table headers. Should the headers be spoken before every cell, or only before a cell with a different header than the previous cell	always once	CSS2
speak-numeral	Specifies how to speak numbers	digits continuous	CSS2
speak-punctuation	Specifies how to speak punctuation characters	none code	CSS2
speech-rate	Specifies the speed of the speaking	number x-slow slow medium fast x-fast faster slower	CSS2
stress	Specifies the "stress" in the speaking voice	number	CSS2
voice-family	A prioritized list of voice family names that contain specific voices	specific-voice generic-voice	CSS2
volume	Specifies the volume of the speaking	number % silent x-soft soft medium loud x-loud	CSS2

CSS Units

Measurements

Unit	Description
%	a percentage of something
in	inch
cm	centimeter
mm	millimeter
em	one em is equal to the font size of the current element
ex	one ex is the x-height of a font, the x-height is usually about half the font-size
pt	point (1 pt is the same as 1/72 inch)
pc	pica (1 pc is the same as 12 points)
px	pixels (a dot on the computer screen)

Colors

Unit	Description
color_name	A color name (red)
rgb(x,x,x)	A rgb value (rgb(255,0,0))
rgb(y%, y%, y%)	A rgb percentage value (rgb(100%,0%,0%))
#rrggbb	A hex number (#ff0000).