docs/5.2/examples/modals/modals.css

.modal-sheet .modal-dialog {
  width: 380px;
  transition: bottom .75s ease-in-out;
}
.modal-sheet .modal-footer {
  padding-bottom: 2rem;
}

.modal-alert .modal-dialog {
  width: 380px;
}

.modal-tour .modal-dialog {
  width: 380px;
}