a {
    color: #000;
    text-decoration: underline;
}

a:hover {
    color: #000;
    text-decoration: underline;
}

a:visited {
    color: #000;
    text-decoration: underline;
}

.book-button {
    display: inline-block;
    margin: 10px 0;
    padding: 10px 30px;
    border-radius: 5px;
    border: 1px solid #000;
    background-color: #000;
    color: #fff !important;
    text-decoration: none;
    -webkit-transition: all .3s ease-in-out;
    -moz-transition: all .3s ease-in-out;
    -o-transition: all .3s ease-in-out;
    -ms-transition: all .3s ease-in-out;
    transition: all .3s ease-in-out;
}

    .book-button:hover {
        background-color: #fff;
        color: #000 !important;
        text-decoration: none;
    }