div#popup button.wpforms-submit {
    background: #4bd367 !important;
    border-radius: 25px !important;
    padding: 10px 20px !important;
    font-size: 15px !important;
    width: 50% !important;
    height: 40px !important;
    margin-top: 25px !important;
    margin-bottom: 20px !important;
    color: #fff;
    border: none;
    cursor: pointer;
}