input[type=range].custom-slider.custom-slider-bullet {
  height: 2em;
  color: #000;
  background: transparent;
  background-image: linear-gradient(to bottom, #000, #666, #000);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 100% 25%;
}
/*==============================*/
/* le curseur                   */
/*==============================*/
input[type=range].custom-slider.custom-slider-bullet::-webkit-slider-thumb {
  width: 5px;
  padding: 2px;                                              /* largeur du bord */
  border: 1px solid #000;
 
  background: linear-gradient(#B300B3, #B300B3) content-box,          /* le centre */
              linear-gradient(#B300B3, #B300B3) border-box;   /* le bord */
}
input[type=range].custom-slider.custom-slider-bullet::-moz-range-thumb {
  width: 5px;
  padding: 2px;                                              /* largeur du bord */
  border: 1px solid #666;
 
   background: linear-gradient(#B300B3, #B300B3) content-box,          /* le centre */
              linear-gradient(#B300B3, #B300B3) border-box;   /* le bord */
}
input[type=range].custom-slider.custom-slider-bullet::-ms-thumb {
  width: 5px;
  padding: 2px;                                              /* largeur du bord */
  border: 1px solid #999;
 
 box-shadow: 0 0 10px #B300B3 inset;
  background: linear-gradient(#B300B3, #B300B3) content-box,          /* le centre */
              linear-gradient(#B300B3? #B300B3) border-box;   /* le bord */
}