$(document).ready(function(){
$(".sombras")
.wrap("<span class='sombra0'><span class='sombra1'><span class='sombra2'>" + "<span class='sombra3'></span></span></span></span>");

$(".esquinas")
.wrap("<span class='esquina0'><span class='esquina1'><span class='esquina2'>" + "<span class='esquina3'></span></span></span></span>");

});