A {
	text-decoration : none;
	color: black;
	}

A:HOVER {
	color: silver;
}
A:VISITED {
	text-decoration : none;
	}
 html, body, #centro {
      height: 100%;
	  width: 100%;
      margin: 0;
      padding: 0;
      border: none;
      text-align: center;
	  vertical-align: middle;

   }