// use Shadow Parts
// https://ionicframework.com/docs/api/toast#css-shadow-parts

ion-toast::part(button) { 
    color: black;
    background: red;
    border-radius: 14px;
}

button:        Any button element that is displayed inside of the toast.
container:     The element that wraps all child elements.
header:     The header text of the toast.
message:     The body text of the toast.