#webform-submission-demande-de-pieces-detachees-add-form {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(430px, 1fr))
}

.form-item-informations-complementaires, #webform-submission-demande-de-pieces-detachees-add-form #edit-actions {
  grid-column: 1/3
}

@media screen and (max-width: 460px) {
  #webform-submission-demande-de-pieces-detachees-add-form  {
    grid-template-columns: 1fr;
  }
  .form-item-informations-complementaires, #webform-submission-demande-de-pieces-detachees-add-form #edit-actions {
    grid-column: 1/2
   }
}