h1{
color:green;
  font-family: verdana;
}
h2{
color:blue;
font-family: verdana;
}
a{
font-family: courier;}

.center {
  margin: auto;
  width: 50%;
  border: 3px solid green;
  padding: 10px;
}

a:link, a:visited {
  background-color: #028A0F;
  color: white;
  padding: 14px 25px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
}

a:hover, a:active {
  background-color: #5DBB63;
}