.progress-custom {
  height: 8px;
  background-color: #eee;
  border-radius: 6px;
  overflow: hidden;
}

.progress-bar-custom {
  background-color: #111; /* đen */
  transition: width 0.4s ease;
}

.progress-bar-custom::after {
  content: "";
  display: block;
  height: 100%;
  width: 100%;
  background: linear-gradient(
    90deg,
    rgba(255,255,255,0.2) 0%,
    rgba(255,255,255,0.4) 50%,
    rgba(255,255,255,0.2) 100%
  );
  animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}