@media (max-width: 920px) {
  .topbar { align-items: flex-start; flex-wrap: wrap; padding: 10px; }
  .topnav { order: 3; width: 100%; overflow-x: auto; padding-top: 4px; }
  .hero { grid-template-columns: 1fr; min-height: auto; padding-top: 70px; }
  .feature-grid, .flow-grid { grid-template-columns: 1fr 1fr; }
  .section-title.row-title { align-items: flex-start; flex-direction: column; }
}
@media (max-width: 620px) {
  .site-shell { width: min(100% - 22px, 1180px); }
  .top-action { display: none; }
  .section-pad { padding: 60px 0; }
  h1 { font-size: clamp(42px, 14vw, 64px); }
  .feature-grid, .flow-grid, .metric-grid { grid-template-columns: 1fr; }
  .interface-body { grid-template-columns: 1fr; }
  .side-rail { display: none; }
  .access-card { align-items: flex-start; flex-direction: column; }
  .footer { flex-direction: column; }
}