.previous :hover {
    background-color: #ddd;
    color: black;
}

.previous {
    background-color: #0077bb;
    color: white;
    width: 100px;
    font-size: large;
    margin-left: 30px;
    text-decoration: none;
    display: inline-block;
    padding: 8px 16px;
}