a {
  text-decoration: none;
  padding: 15px;
  background-color: white;
  border-radius: 5px;
  text-transform: uppercase;
  color: black;
}

.modal {
  visibility: hidden;
  opacity: 0;
  position: absolute;
  top: 0; right: 0;
  bottom: 0; left: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(77, 77, 77, .7);
  transition: all .4s;
}

.modal:target {
  visibility: visible;
  opacity: 1;
}