.slider-container {
  position: relative;
}


.slider-progress {
  border: solid 1px black;
  position: absolute;
  left: 0;
  bottom: 0;
  height: 10px;
  background: linear-gradient(to right, green, blue);
  transition: width 0.09s linear, opacity 0.15s linear;
  opacity: 0;
}


.slider-progress.is-transitioning {
  width: 0% !important;
}


.slider-progress.is-sliding {
  opacity: 1;
}