Leaflet Center Marker Numbers

Does anyone have an idea how to center numbers inside markers? This is the current situation.

Marker with Number

Creating a Marker

    return L.divIcon({
  className: "green-icon",
  iconSize: [25, 41],
  iconAnchor: [10, 44],
  popupAnchor: [3, -40],
  html: markerNumber,
});

CSS

.green-icon {
 background-image: url("../GreenIcon.png");
 background-repeat: no-repeat;
 margin: 0 auto;
 text-align: center;
 color: white;
 font-weight: bold;
 }