a {
  color: black;
  padding: 15px 25px 15px 25px;
  margin: 0px;
  background-color: #ffd54f;
  font-size: 20px;
  font-weight: 500;
  text-decoration: none;
  text-transform: uppercase;
  box-shadow: 1px 1px 3px black;
}

a:hover {
  box-shadow: 2px 2px 5px #444;
}

a:active {
  box-shadow: 0px 0px 1px black;
}