.compose-form__submit button {
  visibility: hidden;
}

.compose-form__submit button:after {
  visibility: visible;
  content:'Toot!'; 
  text-indent: 0;
  display: block;
  border: 2px solid grey;
  border-radius: 5px;
  padding: 2px;
}

.button.button-secondary[href="/publish"] {
  visibility: hidden;
}

.button.button-secondary[href="/publish"]::after {
  visibility: visible;
  content:'Toot!'; 
  text-indent: 0;
  display: block;
  border: 2px solid grey;
  border-radius: 5px;
  padding: 2px;
}