What are Pseudo-Elements
A CSS pseudo-element is used to style specified parts of an element.
For example, it can be used to:
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 NGO 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:
Note: The ::first-line
pseudo-element can only be applied to block-level elements.
The following properties apply to the ::first-line
pseudo-element:
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:
Note: The ::first-letter
pseudo-element can only be applied to block-level elements.
Pseudo-elements and CSS Classes
Pseudo-elements can be combined with CSS classes:
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:
p::first-letter
{
color
: #ff0000;
font-size
: xx-large;
}
p::first-line
{
color
: #0000ff;
font-variant: small-caps;
}
Try it Yourself
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:
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:
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 ::selection
: color
, background
, cursor
, and outline
.
The following example makes the selected text red on a yellow background:
Selector | Example | Example description |
---|---|---|
::after | p::after | Insert something after the content of each <p> element |
::before | p::before | Insert something before the content of each <p> element |
::first-letter | p::first-letter | Selects the first letter of each <p> element |
::first-line | p::first-line | Selects the first line of each <p> element |
::selection | p::selection | Selects the portion of an element that is selected by a user |
Selector | Example | Example description |
---|---|---|
:active | a:active | Selects the active link |
:checked | input:checked | Selects every checked <input> element |
:disabled | input:disabled | Selects every disabled <input> element |
:empty | p:empty | Selects every <p> element that has no children |
:enabled | input:enabled | Selects every enabled <input> element |
:first-child | p:first-child | Selects every <p> elements that is the first child of its parent |
:first-of-type | p:first-of-type | Selects every <p> element that is the first <p> element of its parent |
:focus | input:focus | Selects the <input> element that has focus |
:hover | a:hover | Selects links on mouse over |
:in-range | input:in-range | Selects <input> elements with a value within a specified range |
:invalid | input:invalid | Selects all <input> elements with an invalid value |
:lang(language) | p:lang(it) | Selects every <p> element with a lang attribute value starting with "it" |
:last-child | p:last-child | Selects every <p> elements that is the last child of its parent |
:last-of-type | p:last-of-type | Selects every <p> element that is the last <p> element of its parent |
:link | a:link | Selects all unvisited links |
:not(selector) | :not(p) | Selects every element that is not a <p> element |
:nth-child(n) | p:nth-child(2) | Selects every <p> element that is the second child of its parent |
:nth-last-child(n) | p:nth-last-child(2) | Selects every <p> element that is the second child of its parent, counting from the last child |
:nth-last-of-type(n) | p:nth-last-of-type(2) | Selects every <p> element that is the second <p> element of its parent, counting from the last child |
:nth-of-type(n) | p:nth-of-type(2) | Selects every <p> element that is the second <p> element of its parent |
:only-of-type | p:only-of-type | Selects every <p> element that is the only <p> element of its parent |
:only-child | p:only-child | Selects every <p> element that is the only child of its parent |
:optional | input:optional | Selects <input> elements with no "required" attribute |
:out-of-range | input:out-of-range | Selects <input> elements with a value outside a specified range |
:read-only | input:read-only | Selects <input> elements with a "readonly" attribute specified |
:read-write | input:read-write | Selects <input> elements with no "readonly" attribute |
:required | input:required | Selects <input> elements with a "required" attribute specified |
:root | root | Selects the document's root element |
:target | #news:target | Selects the current active #news element (clicked on a URL containing that anchor name) |
:valid | input:valid | Selects all <input> elements with a valid value |
:visited | a:visited | Selects all visited links |