html {
  text-align: center;
  color: yellow;
  background: black;
  font: 1em "Times New Roman";
  font-size: 25px;
  
  a:link {
    color:red;
    text-decoration: underline;
  }
  
  a:visited {
    color:green;
    text-decoration: underline;
  }
  
  a:hover {
    color:white;
    text-decoration: underline;
  } 
  
  a:active {
    color:hotpink;
    text-decoration: underline;
  } 
}