elk/styles/tiptap.css

.ProseMirror p.is-editor-empty:first-child::before {
  content: attr(data-placeholder);
  float: left;
  pointer-events: none;
  height: 0;
  opacity: 0.4;
}

span[data-type='mention'],
span[data-type='hashtag'] {
  --at-apply: text-primary;
}