.loading-bar {
  width: 100px;
  height: 6px;
  background: linear-gradient(90deg, #333 0%, #ccc 50%, #333 100%);
  background-size: 200% 100%;
  animation: slide 1.2s linear infinite;
}

@keyframes slide {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}