title: CSS: Leaflet markers borders stay displayed as undesirable effect
body: <p>After have changed marker icon (same as original, just colorized), borders are still displayed under Firefox, not from Chromium :</p>
  <p><img src="https://i.stack.imgur.com/NMQLn.jpg" alt="you can see" /></p>
  <p>This CSS code has no effect:</p>
  <pre><code>border: none; / border: 0;
  overflow: hidden;
  </code></pre>
  <p>An idea to force hide this undesirable effect?</p>