@media (min-width: 901px) {
  .period-switch { grid-template-columns: repeat(5, 1fr); }
}

@media (max-width: 900px) and (min-width: 621px) {
  .period-switch { grid-template-columns: repeat(3, 1fr); }
  .period-switch button:nth-child(2) { border-right: 1px solid var(--line); }
  .period-switch button:nth-child(3) { border-right: 0; }
  .period-switch button:nth-child(-n+3) { border-bottom: 1px solid var(--line); }
}