CSS Pseudo Elements
CSS pseudo elements are used to add some special effects to selectors.
Syntax
Pseudo-element syntax:
selector:pseudo-element {property:value;}
CSS classes can also use pseudo-elements:
selector.class:pseudo-element {property:value;}
:first-line pseudo-element
"first-line" pseudo-element is used to add to the first line of text Set special styles.
Note: The "first-line" pseudo-element can only be used for block-level elements.
Note: The following properties can be applied 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
:first-letter pseudo-element
The "first-letter" pseudo-element is used to set a special style to the first letter of text
Note: The "first-letter" pseudo-element can only be used for block-level elements.
Note: The following properties can be applied 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:
p.article:first-letter {color:#ff0000;}
<p class="article ">A paragraph in an article</p>
The above example will make the first letter of all paragraphs with class article turn red.
Multiple Pseudo-elements
Can be used in combination with multiple pseudo-elements.
In the example below, the first letter of the paragraph will be displayed in red and its font size will be xx-large. The rest of the text in the first line will be blue and appear in small caps.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文网</title>
<style>
p:first-letter
{
color:#ff0000;
font-size:xx-large;
}
p:first-line
{
color:#0000ff;
font-variant:small-caps;
}
</style>
</head>
<body>
<p>You can combine the :first-letter and :first-line pseudo-elements to add a special effect to the first letter and the first line of a text!</p>
</body>
</html>CSS - :before pseudo-element
":before" pseudo-element can insert new content before the content of the element.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS ::before 伪元素示例</title>
<style type="text/css" media="all">
div::before
{
background: lightgreen;
content: "张三";
}
</style>
</head>
<body>
<div>今天来学习知识</div>
</body>
</html>CSS - :after pseudo-element
":after" pseudo-element can insert new content after the content of the element.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS ::after 伪元素示例</title>
<style type="text/css" media="all">
div::after
{
background: lightgreen;
content: "周末";
}
</style>
</head>
<body>
<div>今天是</div>
</body>
</html>
Next Section