video-progress {
  display: block;
  position: absolute;
  inset-inline: 10px;
  top: calc(env(safe-area-inset-top, 0px) + 10px);
  height: 5px;
  border-radius: 5px;;
  background: rgba(var(--video-progress),.25);
  pointer-events: none;
}
video-progress .fill {
  width: 0%;
  background: rgb(var(--video-progress));
  transition: width 40ms linear;
}