--- title: Pseudoclasses slug: Web/CSS/Pseudoclasses tags: - CSS - Pseudoclasse - Referencia - Resumo - Seletores - Sinopse translation_of: Web/CSS/Pseudo-classes ---
A CSS pseudo-class is a keyword added to a selector that specifies a special state of the selected element(s). For example, {{CSSxRef(":hover")}} can be used to change a button's color when the user's pointer hovers over it.
/* Any button over which the user's pointer is hovering */
button:hover {
color: blue;
}
Pseudo-classes let you apply a style to an element not only in relation to the content of the document tree, but also in relation to external factors like the history of the navigator ({{CSSxRef(":visited")}}, for example), the status of its content (like {{CSSxRef(":checked")}} on certain form elements), or the position of the mouse (like {{CSSxRef(":hover")}}, which lets you know if the mouse is over an element or not).
Nota: In contrast to pseudo-classes, pseudo-elements can be used to style a specific part of an element.
selector:pseudo-class {
property: value;
}
Like regular classes, you can chain together as many pseudo-classes as you want in a selector.
| Especificação | Estado | Comentário |
|---|---|---|
| {{SpecName("Fullscreen")}} | {{Spec2("Fullscreen")}} | Defined :fullscreen. |
| {{SpecName("HTML WHATWG", "#pseudo-classes")}} | {{Spec2("HTML WHATWG")}} | Defines when particular selectors match HTML elements. |
| {{SpecName("CSS4 Selectors")}} | {{Spec2("CSS4 Selectors")}} | Defined :any-link, :blank, :local-link, :scope, :drop, :current, :past, :future, :placeholder-shown, :user-invalid, :nth-col(), :nth-last-col() and :matches().No significant change for pseudo-classes defined in {{SpecName("CSS3 Selectors")}} and {{SpecName("HTML5 W3C")}} (though semantic meaning not taken over). |
| {{SpecName("HTML5 W3C")}} | {{Spec2("HTML5 W3C")}} | Copies the relevant section from the canonical (WHATWG) HTML spec. |
| {{SpecName("CSS3 Basic UI")}} | {{Spec2("CSS3 Basic UI")}} | Defined :default, :valid, :invalid, :in-range, :out-of-range, :required, :optional, :read-only and :read-write, but without the associated semantic meaning. |
| {{SpecName("CSS3 Selectors")}} | {{Spec2("CSS3 Selectors")}} | Defined :target, :root, :nth-child(), :nth-last-of-child(), :nth-of-type(), :nth-last-of-type(), :last-child, :first-of-type, :last-of-type, :only-child, :only-of-type, :empty and :not().Defined the syntax of :enabled, :disabled, :checked, and :indeterminate, but without the associated semantic meaning.No significant change for pseudo-classes defined in {{SpecName('CSS2.1')}}. |
| {{SpecName("CSS2.1")}} | {{Spec2("CSS2.1")}} | Defined :lang(), :first-child, :hover, and :focus.No significant change for pseudo-classes defined in {{SpecName('CSS1')}}. |
| {{SpecName("CSS1")}} | {{Spec2("CSS1")}} | Defined :link, :visited and :active, but without the associated semantic meaning. |