.media-gallery__item-thumbnail img:not([alt]),
.audio-player__canvas:not([title]),
.video-player video:not([title]), 
.media-gallery__gifv video:not([title])
 {
    border: 2px solid red;
    box-sizing: border-box;
}
.compose-form__actions .button { color: rgba(255,255,255,0); }
.compose-form__actions .button::before {
  content: "Tröt!";
  position: absolute;
  top: 50%;
  left: 50%;
  color: rgba(255,255,255,1);
  transform: translate3d(-50%, -50%, 0);
}