rstudio-leaflet.css

.leaflet-tooltip.leaflet-tooltip-text-only,
.leaflet-tooltip.leaflet-tooltip-text-only:before,
.leaflet-tooltip.leaflet-tooltip-text-only:after {
  background: none;
  border: none;
  box-shadow: none;
}

.leaflet-tooltip.leaflet-tooltip-text-only.leaflet-tooltip-left {
  margin-left: 5px;
}

.leaflet-tooltip.leaflet-tooltip-text-only.leaflet-tooltip-right {
  margin-left: -5px;
}

.leaflet-tooltip:after {
  border-right: 6px solid transparent;
  /* right: -16px; */
}

.leaflet-popup-pane .leaflet-popup-tip-container {
  /* when the tooltip container is clicked, it is closed */
  pointer-events: all;
  /* tooltips should display the "hand" icon, just like .leaflet-interactive*/
  cursor: pointer;
}

/* have the widget be displayed in the right 'layer' */
.leaflet-map-pane {
  z-index: auto;
}

/* Add missing rule from leaflet for img.
This complete existing leaflet.css.
Fix for https://github.com/rstudio/rmarkdown/issues/1949 */
.leaflet-container .leaflet-right-pane img,
.leaflet-container .leaflet-left-pane img {
	max-width: none !important;
	max-height: none !important;
}