:host ::ng-deep.ngb-dp-arrow button:disabled {
    color: #4a4a4a;
    background-color: #fff;
    opacity: 0.25;
    cursor: not-allowed;
}

:host ::ng-deep.ngb-dp-arrow button:disabled .ngb-dp-navigation-chevron {
    color: #4a4a4a;
}

:host ::ng-deep.ngb-dp-arrow button .ngb-dp-navigation-chevron {
    color: #000;
}