@media (max-width: 1100px) {
  .kpi-grid { grid-template-columns: repeat(3, minmax(150px, 1fr)); }
  .upload-grid, .meta-form, .filters, .chart-grid, .split-layout { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .app-header { position: static; display: grid; padding: 16px; }
  .app-shell { grid-template-columns: 1fr; }
  .side-nav { display: flex; gap: 6px; overflow-x: auto; border-left: 0; border-bottom: 1px solid var(--border); }
  .nav-item { width: auto; white-space: nowrap; }
  .content { padding: 16px; }
  .kpi-grid { grid-template-columns: 1fr 1fr; }
  .section-heading { display: grid; }
}