CSS Links

Styling Links

Links can be styled with any CSS property (e.g. color, font-family, background, etc.).

Special for links are that they can be styled differently depending on what state they are in.

The four links states are:

• a:link - a normal, unvisited link
• a:visited - a link the user has visited
• a:hover - a link when the user mouses over it
• a:active - a link the moment it is clicked

Example

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 */

When setting the style for several link states, there are some order rules:

• a:hover MUST come after a:link and a:visited
• a:active MUST come after a:hover

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Common Link Styles

In the example above the link changes color depending on what state it is in.

Lets go through some of the other common ways to style links:

Text Decoration

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

Example

a:link {text-decoration:none;}
a:visited {text-decoration:none;}
a:hover {text-decoration:underline;}
a:active {text-decoration:underline;}

Background Color

The background-color property specifies the background color for links:

Example

a:link {background-color:#B2FF99;}
a:visited {background-color:#FFFF85;}
a:hover {background-color:#FF704D;}
a:active {background-color:#FF704D;}

Styling Fonts CSS

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")

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;}

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;}

Font Size

The font-size property sets the size of the text.

Being able to manage the text size is important in web design. However, you should not use font size adjustments to make paragraphs look like headings, or headings look like paragraphs.

Always use the proper HTML tags, like <h1> - <h6> for headings and <p> for paragraphs.

The font-size value can be an absolute, or relative size.

Absolute size:

• Sets the text to a specified size
• Does not allow a user to change the text size in all browsers (bad for accessibility reasons)
• Absolute size is useful when the physical size of the output is known

Relative size:

• Sets the size relative to surrounding elements
• Allows a user to change the text size in browsers

• 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;}

  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 */

  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;}

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

CSS Text

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"

• Example

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

  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;}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;}

  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;}

  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;}

  Text Indentation

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

  Example

  p {text-indent:50px;}

  
  

  
  

CSS Styling

CSS Background

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;}

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;}

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');}

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');}

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');
}

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;
}

Background Image - Set position and no-repeat

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

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;
}

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;}

Three Ways to Insert CSS

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");}

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>
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.

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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:

1. Browser default
2. External style sheet
3. Internal style sheet (in the head section)
4. 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).

CSS Id and Class

The id and class Selectors

In addition to setting a style for a HTML element, CSS allows you to specify your own selectors called "id" and "class".

---

The id Selector

The id selector is used to specify a style for a single, unique element.

The id selector uses the id attribute of the HTML element, and is defined with a "#".

The style rule below will be applied to the element with id="para1":

Example

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

The class Selector

The class selector is used to specify a style for a group of elements. Unlike the id selector, the class selector is most often used on several elements.

This allows you to set a particular style for many HTML elements with the same class.

The class selector uses the HTML class attribute, and is defined with a "."

In the example below, all HTML elements with class="center" will be center-aligned:

Example

.center {text-align:center;}You can also specify that only specific HTML elements should be affected by a class.

In the example below, all p elements with class="center" will be center-aligned:

Example

p.center {text-align:center;}

CSS Syntax

EXEMPLE 1

<html>
<head>
<style>
body {background-color:yellow;}
h1   {font-size:36pt;}
h2   {color:blue;}
p    {margin-left:50px;}
</style>
</head>

<body>

<h1>This header is 36 pt</h1>
<h2>This header is blue</h2>

<p>This paragraph has a left margin of 50 pixels</p>

</body>
</html>

EXEMPLE 2


<html>
<head>
<style>
body {background-color:tan;}
h1   {color:maroon;font-size:20pt;}
hr   {color:navy;}
p    {font-size:11pt;margin-left:15px;}
a:link    {color:green;}
a:visited {color:yellow;}
a:hover   {color:black;}
a:active  {color:blue;}
</style>
</head>

<body>

<h1>This is a header 1</h1>
<hr>

<p>You can see that the style
sheet formats the text</p>

<p><a href="http://www.w3schools.com"
target="_blank">This is a link</a></p>

</body>
</html>