HTML5 progress bar "ending" styling

I want to style the "ending" of the current progress of the HTML5 progress bar by adding small black dot to it, see the screen. So this dot must move as progress moves

But the code I found here doesn't work anymore. It worked few weeks ago or so, but now it's not - see the codepen

Maybe someone knows what happened or how to achieve my goal?

Thanks a lot!

P.S. Here is the HTML/CSS I use

HTML:

<progress value="1400" max="4261"></progress>

CSS

progress {

  /* Positioning */
  position: absolute;
  left: 0;
  top: 0;

  /* Dimensions */
  width: 100%;
  height: 50px;

  /* Reset the appearance */
  -webkit-appearance: none;
     -moz-appearance: none;
          appearance: none;

  /* Get rid of the default border in Firefox/Opera. */
  border: none;

  /* Progress bar container for Firefox/IE10+ */
  background-color: transparent;

  /* Progress bar value for IE10+ */
  color: #00D38D;
}

progress[value]::-webkit-progress-value {
  position: relative;
  background: #00d38d;  
}

progress[value]::-webkit-progress-value::after {
  content: '';
  width: 20px;
  height: 20px;
  position: absolute;
  right: 10px;
  top: 15px;
  border-radius: 50px;
  background: black;
}

progress::-webkit-progress-bar {
  background-color: transparent;
}

progress::-webkit-progress-value {
  background-color: #00D38D;
}

progress::-moz-progress-bar {
  background-color: #00D38D;
}