// UI element changes

div[class^="slider-"] {
  div[class^="track-"] {
    div[class^="grabber-"] {
      @half: (@rounder / 2);
      width: @rounder;
      height: @rounder;
      border: none;
      border-radius: @half;
      margin-top: -@half;
      margin-left: -@half;
    }
  }
}