.flow-three {
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr);
}

@media (max-width: 850px) {
  .flow-three {
    grid-template-columns: 1fr;
  }

  .flow-three .arrow {
    transform: rotate(90deg);
    text-align: center;
  }
}