map-tool/public/assets/esri/themes/base/_Overlay.scss

.esri-overlay-surface {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 0;
  margin: 0;
  border: none;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
  user-select: none;
}