a.sso-login-link {
    background-color: #000;
    border-radius: 4px;
    border-color: var(--wp--preset--color--transparent);
    border-width: 4px;
    border-style: solid;
    color: #fff;
    font-family: inherit;
    font-size: var(--wp--preset--font-size--small);
    font-weight: 700;
    line-height: inherit;
    padding: .1rem .5rem;
    text-decoration: none;
}