.core-textarea-markdown.control-invalid .toastui-editor-contents {
  background-color: rgb(255, 0, 0);
}

.core-textarea-markdown.readonly .toastui-editor-toolbar button {
  pointer-events: none;
  opacity: 0.5;
}

.core-textarea-markdown .toastui-editor-tabs {
  display: none !important;
}
.core-textarea-markdown .toastui-editor-mode-switch {
  display: none !important;
}
.toastui-editor-contents {
    font-family: unset;
    font-size: unset;
}
.toastui-editor-contents hr {
    border-top: 1px solid #dbdbdb;
}