:host {
  display: inline-block;
  --bar-color: red;
}

.container {
  width: 300px;
  height: 25px;
  background: #ddd;
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}

.valueBar {
  width: 0%;
  height: 100%;
  background-color: var(--bar-color);

  background-image: linear-gradient(
    45deg,
    rgba(255,255,255,0.3) 25%,
    rgba(255,255,255,0) 25%,
    rgba(255,255,255,0) 50%,
    rgba(255,255,255,0.3) 50%,
    rgba(255,255,255,0.3) 75%,
    rgba(255,255,255,0) 75%,
    rgba(255,255,255,0) 100%
  );

  background-size: 40px 40px;
  animation: barberpole 1s linear infinite;
  transition: width 0.3s ease;
}

.valueBar.complete {
  animation: none;
}

@keyframes barberpole {
  from { background-position: 0 0; }
  to   { background-position: 40px 0; }
}