@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
  }
  .main-header {
    flex-wrap: wrap;
    gap: 8px;
  }
  .nav-links {
    display: none;
  }
}

@media (max-width: 640px) {
  .hero {
    margin: 20px 10px;
    padding: 18px 16px;
  }
  .section {
    margin: 0 10px 18px;
    padding: 14px 14px 18px;
  }
  .grid-3 {
    grid-template-columns: 1fr;
  }
  .plan-grid {
    grid-template-columns: 1fr;
  }
  .main-footer {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    margin: 14px 10px 20px;
  }
}