.tpl_div { display: flex; flex-flow: row wrap; justify-content: space-between; width: 100%; }
.tpl_div > div { width: 30%; }

@media (min-width: 480px) and (max-width: 768px) {
  .tpl_div > div { width: 48%; margin: 0.5em 0; }
}

@media (max-width: 479px) {
  .tpl_div { display: flex; flex-flow: column; }
  .tpl_div > div { width: 100%; margin: 0.5em 0; }
}