client/securedrop_client/gui/auth/sign_in/button.css

QWidget {
    font-family: 'Source Sans Pro';
}

#SignInButton {
    border: none;
    background-color: #05edfe;
    font-family: 'Montserrat';
    font-weight: 600;
    font-size: 14px;
    color: #2a319d;
}

#SignInButton:pressed {
    background-color: #85f6fe;
}