@media (max-width: 860px) {
  .app-shell { padding: 18px; }
  .app-header { display: block; }
  .build-badge { display: inline-block; margin-top: 8px; }
  .workspace { grid-template-columns: 1fr; }
  .controls-panel { position: static; }
  .preview-panel { min-height: 480px; }
  .preview-stage { min-height: 420px; }
}

@media (max-width: 520px) {
  .field-grid { grid-template-columns: 1fr; }
  .panel { border-radius: 14px; }
}