D8_rplf/modules/field_group/css/field_group.field_ui.css

#field-overview tr.field-group .group-label,
#field-display-overview tr.field-group .group-label {
  font-weight: bold;
}

#field-overview tr.static-region,
#field-display-overview tr.static-region {
	background-color: #ddd;
}

#edit-refresh {
  display:none;
}