/*
See https://dotscrapbook.wordpress.com/2014/11/28/simple-numbered-markers-with-leaflet-js/,
https://github.com/IvanSanchez/Leaflet.Marker.Stack/blob/gh-pages/Leaflet.Marker.Stack.js,
https://gis.stackexchange.com/questions/360293/add-something-into-l-circlemarker
Donald-Duck-2-icon.png by Pino (https://iconarchive.com/artist/pino.html), free for non-commercial use.

Example css
===========
*/

 .circle {
    display: table-cell;
    text-align: center;
    vertical-align: middle;
    border-radius: 50%;
    border-style: solid;
    font-size: 16px;
    font-weight: bold;
  }
  
  .circle.circle1 {
    background: rgba(0, 57, 128, 0.2);
    border-color: #3388FF;
    color: white;
  }
  
  .circle.circle2 {
    background: rgba(0, 57, 128, 0.2);
    border-color: green;
    border-radius: 50%;
    color: yellow;
  }
  
  .circle.circle3 {
    background-color: rgba(0, 57, 128, 0.2);
    background-image: url('Donald-Duck-2-icon.png');
    background-position: center;
    background-repeat: no-repeat;
    border-color: green;
    border-radius: 0;
    color: yellow;
  }