A CSS pseudo-class is a keyword added to a selector that specifies a special state of the selected element(s). For example, :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 (:visited
, for example), the status of its content (like :checked
on certain form elements), or the position of the mouse (like :hover
, which lets you know if the mouse is over an element or not).
Note: In contrast to pseudo-classes, pseudo-elements can be used to style a specific part of an element.