discourse/plugins/chat/assets/stylesheets/mobile/chat-thread.scss

.chat-thread {
  &__body {
    margin: 0 1px 0 0;
  }
}

.thread-toast {
  .toast-hide {
    font-size: var(--font-down-1);
  }

  .toast-action {
    position: absolute;
    bottom: 0;
    right: 0;
  }
}