Pseudo classes a:linklink in normal state a:activelink in clicked state a:hoverlink with mouse over it a:visitedvisited link p::after{content:"yo";}add content after p p::beforeadd content before p input:checkedchecked inputs input:disableddisabled inputs input:enabledenabled inputs input:focusinput has focus input:in-rangevalue in range input:out-of-rangeinput value out of range input:validinput with valid value input:invalidinput with invalid value input:optionalno required attribute input:requiredinput with requred attribute input:read-onlywith readonly attribute input:read-writeno readonly attrib. div:emptyelement with no children p::first-letterfirst letter in p p::first-linefirst line in p p:first-of-typefirst of some type p:last-of-typelast of some type p:lang(en)p with en language attribute :not(span)element that's not a span p:first-childfirst child of its parent p:last-childlast child of its parent p:nth-child(2)second child of its parent p:nth-child(3n+1)nth-child (an + b) formula p:nth-last-child(2)second child from behind p:nth-of-type(2)second p of its parent p:nth-last-of-type(2)...from behind p:only-of-typeunique of its parent p:only-childonly child of its parent :rootdocuments root element ::selectionportion selected by user :targethighlight active anchor