^^css Pseudo-class selector.

Lo stato degli elementi

La necessita' e' che gli elementi non siano invariabili, ma con uno stile che si adatti al loro stato

:hover to change style when the pointer hovers over it
:checked to change style in relation to the status of its content
:link          represents an element that has not yet been visited.
                 It matches every unvisited <a>, <area>, or <link> element that
                 has an href attribute.
:visited to change style when the link has been visited

CSS pseudo-class is a keyword added to a selector to select a state of the selected element(s) to apply them a style.

/* Any button over which the user's pointer is hovering */ button:hover {color: blue;}

selector:pseudo-class {property: value;}

Like regular classes, you can chain together as many pseudo-classes as you want in a selector.