@olegrumiancev/sp-react-formfields/src/fields/FieldTextRenderer.css

Collection of React controls used for rendering SharePoint fields in custom forms. Support new/edit/display rendering modes.

.ms-TextField-fieldGroup {
  border-top: 0;
  border-left: 0;
  border-right: 0;
  border-bottom: 1px solid #a6a6a6;
}