.btn {
    border-radius:2px ;

  border-style: solid;
  border-width:5px;
    width: 150px;
  height: 150px;
  background-color:white;
  padding: 16px 32px;
  text-align: center;
  font-size: 16px;
  margin: 4px 2px;
  opacity: 0.6;
  transition: 0.3s;
}

.btn:hover {opacity: 1}