A = Estilos en línea, B = IDs, C = clases, D = elementos html
#caja header h1 { color: red; }	A = 0, B = 1, C = 0, D = 2 Total = 0,1,0,2
#caja .cabecera h1 { color: blue; }	A = 0, B = 1, C = 1, D = 1 Total = 0,1,1,1
#caja h1 { color: greenyellow; }	A = 0, B = 1, C = 0, D = 1 Total = 0,1,0,1
h1 { color: violet; }	A = 0, B = 0, C = 0, D = 2 Total = 0,0,0,2
h1 { color: coral; }	A = 0, B = 0, C = 0, D = 1 Total = 0,0,0,1