body {
  background-color: black;
  color: black;
  font-family: Verdana;
}

div {
  color: black;
  background-color: white;
  padding-top: 100%;
  padding-bottom: 100%;
  margin-left: 50%;
  margin-right: 50%;
  }
  
.button {
  color: white;
  background-color: black;
  }
  
.button:hover {
    color: yellow;
    }
    
a:link {
  text-decoration: none;
  }