CSS: pseudo-classes and pseudo-elements 1.Definition: pseudo-classes The pseudo-class concept is introduced to permit selection based on information that lies outside of the document tree or that cannot be expressed using the other simple selectors. In Chinese:引入伪类概念是为了允许基于文档树之外的...
The double colon replaced the single-colon notation for pseudo-elements in CSS3. This was an attempt from W3C to distinguish betweenpseudo-classesandpseudo-elements. The single-colon syntax was used for both pseudo-classes and pseudo-elements in CSS2 and CSS1. For backward compatibility, the si...
CSSPseudo-elements 伪元素是一个附加至选择器末的关键词,允许对被选择元素的特定部分修改样式。CSS伪元素是一种样式化文档元素的方法,这些元素没有由文档树中的位置明确定义。 一、什么是伪元素? CSS伪元素允许设置元素或元素部分的样式,而无需向其添加任何ID或类。当只想为段落的第一个字母设置样式以创建首字下...
a:hoverMUST come aftera:linkanda:visitedin the CSS definition in order to be effective! a:activeMUST come aftera:hoverin the CSS definition in order to be effective! Pseudo-class names are not case-sensitive. <!DOCTYPE html> /* unvisited link */ a:link { color: red; } /* visi...
注意:与伪类相比,pseudo-elements可以用来设置元素的特定部分。 语法 代码语言:javascript 复制 selector:pseudo-class { property: value; } 像常规类一样,您可以在选择器中链接尽可能多的伪类。 标准伪类的索引 :active :any :checked :default :dir() :disabled :empty :enabled :first :first-child :first-...
css类也可以与伪元素配合使用: select.class:pseudo-element{property:value;} :first-line伪元素, "first-line"伪元素用于向文本的首行设置特殊样式, p:first-line{ color:#ff0000; font-variant:small-caps; } 注释:"first-line"伪元素只能用于块级元素. ...
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-letter Pseudo-element The::first-letterpseudo-element is used to add a special styl...
CSS Pseudo-elements(伪元素)简介 CSS伪元素是CSS提供的一种特殊选择器,可以在元素的前面或后面插入内容,并且可以使用CSS样式对这些内容进行修饰。伪元素不是真实的DOM元素,而是在渲染过程中由CSS创建的。 在CSS中,伪元素通过使用两个冒号(::)来表示,例如`::before`和`::after`。在旧版本的CSS中,单冒号(:)也...
cssCopy to Clipboard /* The first line of every element. */ p::first-line { color: blue; text-transform: uppercase; } Double colons (::) are used for pseudo-elements. This distinguishes pseudo-elements from pseudo-classes that use a single colon (:) in their notation. Note, browse...
CSS Pseudo-elements 伪元素是一个附加至选择器末的关键词,允许对被选择元素的特定部分修改样式。CSS伪元素是一种样式化文档元素的方法,这些元素没有由文档树中的位置明确定义。 CSS Pseudo-elements 伪元素是一个附加至选择器末的关键词,允许对被选择元素的特定部分修改样式。CSS伪元素是一种样式化文档元素的方法,...