Thursday, August 16, 2012

CSS Font

CSS font properties define the font family, boldness, size, and the style of a text.

Difference Between Serif and Sans-serif Fonts

On computer screens, sans-serif fonts are considered easier to read than serif fonts.

CSS Font Families

In CSS, there are two types of font family names:

generic family - a group of font families with a similar look (like "Serif" or "Monospace")
font family - a specific font family (like "Times New Roman" or "Arial")

Generic family	Font family	Description
Serif	Times New Roman Georgia	Serif fonts have small lines at the ends on some characters
Sans-serif	Arial Verdana	"Sans" means without - these fonts do not have the lines at the ends of characters
Monospace	Courier New Lucida Console	All monospace characters have the same width

Font Family

The font family of a text is set with the font-family property.

The font-family property should hold several font names as a "fallback" system. If the browser does not support the first font, it tries the next font.

Start with the font you want, and end with a generic family, to let the browser pick a similar font in the generic family, if no other fonts are available.

Note: If the name of a font family is more than one word, it must be in quotation marks, like font-family: "Times New Roman".

More than one font family is specified in a comma-separated list:

Example

p{font-family:"Times New Roman", Times, serif;}

Try it yourself »

For more commonly used font combinations, look at our Web Safe Font Combinations.

Font Style

The font-style property is mostly used to specify italic text.

This property has three values:

normal - The text is shown normally
italic - The text is shown in italics
oblique - The text is "leaning" (oblique is very similar to italic, but less supported)

Example

p.normal {font-style:normal;}
p.italic {font-style:italic;}
p.oblique {font-style:oblique;}

Try it yourself »

Set Font Size With Pixels

Setting the text size with pixels gives you full control over the text size:

Example

h1 {font-size:40px;}
h2 {font-size:30px;}
p {font-size:14px;}

Try it yourself »

The example above allows Internet Explorer 9, Firefox, Chrome, Opera, and Safari to resize the text.

Note: The example above does not work in IE, prior version 9.

The text can be resized in all browsers using the zoom tool (however, this resizes the entire page, not

just the text).

Set Font Size With Em

To avoid the resizing problem with older versions of Internet Explorer, many developers use em instead of pixels.

The em size unit is recommended by the W3C.

1em is equal to the current font size. The default text size in browsers is 16px. So, the default size of 1em is 16px.

The size can be calculated from pixels to em using this formula: pixels/16=em

Example

h1 {font-size:2.5em;} /* 40px/16=2.5em */
h2 {font-size:1.875em;} /* 30px/16=1.875em */
p {font-size:0.875em;} /* 14px/16=0.875em */

Try it yourself »

In the example above, the text size in em is the same as the previous example in pixels. However, with the em size, it is possible to adjust the text size in all browsers.

Unfortunately, there is still a problem with older versions of IE. The text becomes larger than it should when made larger, and smaller than it should when made smaller.

Use a Combination of Percent and Em

The solution that works in all browsers, is to set a default font-size in percent for the <body> element:

Example

body {font-size:100%;}
h1 {font-size:2.5em;}
h2 {font-size:1.875em;}
p {font-size:0.875em;}

Try it yourself »

Our code now works great! It shows the same text size in all browsers, and allows all browsers to zoom or resize the text!

More Examples

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

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

All CSS Font Properties

Property	Description
font	Sets all the font properties in one declaration
font-family	Specifies the font family for text
font-size	Specifies the font size of text
font-style	Specifies the font style for text
font-variant	Specifies whether or not a text should be displayed in a small-caps font
font-weight	Specifies the weight of a font

TEXT FORMATTING

This text is styled with some of the text formatting properties. The heading uses the text-align, text-transform, and color properties. The paragraph is indented, aligned, and the space between characters is specified. The underline is removed from the "Try it yourself" link.

Text Color

The color property is used to set the color of the text.

With CSS, a color is most often specified by:

a HEX value - like "#ff0000"
an RGB value - like "rgb(255,0,0)"
a color name - like "red"

Look at CSS Color Values for a complete list of possible color values.

The default color for a page is defined in the body selector.

Example

body {color:blue;}
h1 {color:#00ff00;}
h2 {color:rgb(255,0,0);}

Try it yourself »

For W3C compliant CSS: If you define the color property, you must also define the background-color property.

Text Alignment

The text-align property is used to set the horizontal alignment of a text.

Text can be centered, or aligned to the left or right, or justified.

When text-align is set to "justify", each line is stretched so that every line has equal width, and the left and right margins are straight (like in magazines and newspapers).

Example

h1 {text-align:center;}
p.date {text-align:right;}
p.main {text-align:justify;}

Try it yourself »

Text Decoration

The text-decoration property is used to set or remove decorations from text.

The text-decoration property is mostly used to remove underlines from links for design purposes:

Example

a {text-decoration:none;}

Try it yourself »

It can also be used to decorate text:

Example

h1 {text-decoration:overline;}
h2 {text-decoration:line-through;}
h3 {text-decoration:underline;}
h4 {text-decoration:blink;}

Try it yourself »

It is not recommended to underline text that is not a link, as this often confuses users.

Text Transformation

The text-transform property is used to specify uppercase and lowercase letters in a text.

It can be used to turn everything into uppercase or lowercase letters, or capitalize the first letter of each word.

Example

p.uppercase {text-transform:uppercase;}
p.lowercase {text-transform:lowercase;}
p.capitalize {text-transform:capitalize;}

Try it yourself »

Text Indentation

The text-indentation property is used to specify the indentation of the first line of a text.

Example

p {text-indent:50px;}

Try it yourself »

More Examples

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

Specify the space between lines
This example demonstrates how to specify the space between the lines in a paragraph.

Set the text direction of an element
This example demonstrates how to change the text direction of an element.

Increase the white space between words
This example demonstrates how to increase the white space between words in a paragraph.

Disable text wrapping inside an element
This example demonstrates how to disable text wrapping inside an element.

Vertical alignment of an image
This example demonstrates how to set the vertical align of an image in a text.

All CSS Text Properties

Property	Description
color	Sets the color of text
direction	Specifies the text direction/writing direction
letter-spacing	Increases or decreases the space between characters in a text
line-height	Sets the line height
text-align	Specifies the horizontal alignment of text
text-decoration	Specifies the decoration added to text
text-indent	Specifies the indentation of the first line in a text-block
text-shadow	Specifies the shadow effect added to text
text-transform	Controls the capitalization of text
unicode-bidi
vertical-align	Sets the vertical alignment of an element
white-space	Specifies how white-space inside an element is handled
word-spacing	Increases or decreases the space between words in a text

CSS Background

CSS background properties are used to define the background effects of an element.

CSS properties used for background effects:

background-color
background-image
background-repeat
background-attachment
background-position

Background Color

The background-color property specifies the background color of an element.

The background color of a page is defined in the body selector:

Example

body {background-color:#b0c4de;}

Try it yourself »

With CSS, a color is most often specified by:

a HEX value - like "#ff0000"
an RGB value - like "rgb(255,0,0)"
a color name - like "red"

Look at CSS Color Values for a complete list of possible color values.

In the example below, the h1, p, and div elements have different background colors:

Example

h1 {background-color:#6495ed;}
p {background-color:#e0ffff;}
div {background-color:#b0c4de;}

Try it yourself »

Background Image

The background-image property specifies an image to use as the background of an element.

By default, the image is repeated so it covers the entire element.

The background image for a page can be set like this:

Example

body {background-image:url('paper.gif');}

Try it yourself »

Below is an example of a bad combination of text and background image. The text is almost not readable:

Example

body {background-image:url('bgdesert.jpg');}

Try it yourself »

Background Image - Repeat Horizontally or Vertically

By default, the background-image property repeats an image both horizontally and vertically.

Some images should be repeated only horizontally or vertically, or they will look strange, like this:

Example

body
{
background-image:url('gradient2.png');
}

Try it yourself »

If the image is repeated only horizontally (repeat-x), the background will look better:

Example

body
{
background-image:url('gradient2.png');
background-repeat:repeat-x;
}

Try it yourself »

Background Image - Set position and no-repeat

When using a background image, use an image that does not disturb the text.

Showing the image only once is specified by the background-repeat property:

Example

body
{
background-image:url('img_tree.png');
background-repeat:no-repeat;
}

Try it yourself »

In the example above, the background image is shown in the same place as the text. We want to change the position of the image, so that it does not disturb the text too much.

The position of the image is specified by the background-position property:

Example

body
{
background-image:url('img_tree.png');
background-repeat:no-repeat;
background-position:right top;
}

Try it yourself »

Background - Shorthand property

As you can see from the examples above, there are many properties to consider when dealing with backgrounds.

To shorten the code, it is also possible to specify all the properties in one single property. This is called a shorthand property.

The shorthand property for background is simply "background":

Example

body {background:#ffffff url('img_tree.png') no-repeat right top;}

Try it yourself »

When using the shorthand property the order of the property values is:

background-color
background-image
background-repeat
background-attachment
background-position

It does not matter if one of the property values is missing, as long as the ones that are present are in this order.

This example uses more advanced CSS. Take a look: Advanced example

More Examples

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 CSS Background Properties

Property	Description
background	Sets all the background properties in one declaration
background-attachment	Sets whether a background image is fixed or scrolls with the rest of the page
background-color	Sets the background color of an element
background-image	Sets the background image for an element
background-position	Sets the starting position of a background image
background-repeat	Sets how a background image will be repeated

CSS How to Work

When a browser reads a style sheet, it will format the document according to it.

Three Ways to Insert CSS

There are three ways of inserting a style sheet:

External style sheet
Internal style sheet
Inline style

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>

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");}

Do not add a space between the property value and the unit (such as margin-left:20 px). The correct way is: margin-left:20px

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 of an HTML page, 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>

Inline Styles

An inline style loses many of the advantages of style sheets by mixing content with presentation. Use this method sparingly!

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="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.

Multiple Styles Will Cascade into One

Styles can be specified:

inside an HTML element
inside the head section of an HTML page
in an external CSS file

Tip: Even multiple external style sheets can be referenced inside a single HTML document.

Cascading order

What style will be used when there is more than one style specified for an HTML element?

Generally speaking we can say that all the styles will "cascade" into a new "virtual" style sheet by the following rules, where number four has the highest priority:

Browser default
External style sheet
Internal style sheet (in the head section)
Inline style (inside an HTML element)

So, an inline style (inside an HTML element) has the highest priority, which means that it will override a style defined inside the <head> tag, or in an external style sheet, or in a browser (a default value).

Note: If the link to the external style sheet is placed after the internal style sheet in HTML <head>, the external style sheet will override the internal style sheet!