body {
  background-color: #DDDDDD;
  text-align: center;
}
a {
    color: black;
    text-align: center;
    vertical-align: middle;
    border: 1px solid black;
    padding: 44px;
    margin: 1em;
    text-decoration: none;
    font-size: 1.5em;
    display: inline-block;
    background-color: white;
}
a:hover {
    text-decoration: underline;
    background-color: cyan;
}