whats the difference between a{color:blue;} a:link{color:blue;} :link{color:blue;} ive been using the first as i was learning i thought it was the way to select unvisited links, know i read there is a specific unvisited pseudo class :link and then i read people advice to not use a:link and change it for :link without ,a, because of some anchor naming issue i dont understand. would you please explain me i suppose im confused and wrong about how that works.