una/modules/boonex/lucid/data/template/system/css/editor.css

blockquote {
  /* NOTE: copied from common.css */
  border-left: 2px solid #ccc;
  padding-left: 10px;
}
pre {
  /* NOTE: copied from common.css */
  padding: 5px;
  border: 1px solid green;
  background-color: white;
  color: #009900;
  display: block;
  margin: 0;
  overflow-x: auto;
}
.bx-hide-in-htmleditor {
  display: none;
}
.ql-toolbar.ql-snow {
  border: none !important;
  border-bottom: 1px solid rgba(50, 100, 180, 0.2) !important;
}
.ql-container.bx-form-input-html-quill-empty.ql-snow {
  border-radius: 0.3rem;
}