CSS Pseudo Element

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What are Pseudo-Elements?

A CSS pseudo-element is used to style specified parts of an element.

For example, it can be used to:

  • Style the first letter, or line, of an element
  • Insert content before, or after, the content of an element

Syntax

The syntax of pseudo-elements:

selector::pseudo-element {
    property:value;
}

Notice the double colon notation - ::first-line versus :first-line

The double colon replaced the single-colon notation for pseudo-elements in CSS3. This was an attempt from W3C to distinguish between pseudo-classes and pseudo-elements.

The single-colon syntax was used for both pseudo-classes and pseudo-elements in CSS2 and CSS1.

For backward compatibility, the single-colon syntax is acceptable for CSS2 and CSS1 pseudo-elements.


The ::first-line Pseudo-element

The ::first-line pseudo-element is used to add a special style to the first line of a text.

The following example formats the first line of the text in all <p> elements:

Example 

p::first-line {
    color: #ff0000;
    font-variant: small-caps;

}

Note: The ::first-line pseudo-element can only be applied to block-level elements.

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

 

The ::first-letter Pseudo-element

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

The following example formats the first letter of the text in all <p> elements: 

Example

p::first-letter {
    color: #ff0000;
    font-size: xx-large;

}

Note: The ::first-letter pseudo-element can only be applied to block-level elements.

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

Pseudo-elements and CSS Classes

Pseudo-elements can be combined with CSS classes: 

Example

p.intro::first-letter {
    color: #ff0000;
    font-size:200%;

}

The example above will display the first letter of paragraphs with class="intro", in red and in a larger size.


Multiple Pseudo-elements

Several pseudo-elements can also be combined.

In the following example, the first letter of a paragraph will be red, in an xx-large font size. The rest of the first line will be blue, and in small-caps. The rest of the paragraph will be the default font size and color:

Example

 

CSS - The ::before Pseudo-element

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

The following example inserts an image before the content of each <h1> element:

Example

h1::before {
    content: url(smiley.gif);
}

CSS - The ::after Pseudo-element

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

The following example inserts an image after the content of each <h1> element:

Example

h1::after {
    content: url(smiley.gif);
}

CSS - The ::selection Pseudo-element

The ::selection pseudo-element matches the portion of an element that is selected by a user.

The following CSS properties can be applied to ::selectioncolorbackgroundcursor, and outline.

The following example makes the selected text red on a yellow background:

Example

::selection {
    color: red; 
    background: yellow;

}