form:not(.flex) > div ~ input[type="submit"].btn,
form:not(.flex) > div ~ button[type="submit"].btn {
  margin-top: 1rem;
}

.app-modal form:not(.flex) > input[type="submit"].btn,
.app-modal form:not(.flex) > button[type="submit"].btn {
  display: block;
  min-width: 10rem;
  margin-inline: auto;
}