img[loading="lazy"]:not(.fbm-img-loaded) {
  background: linear-gradient(100deg, #ececec 30%, #f7f7f7 50%, #ececec 70%);
  background-size: 300% 100%;
  animation: fbm-img-shimmer 1.3s ease-in-out infinite;
}

@keyframes fbm-img-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

@media (prefers-reduced-motion: reduce) {
  img[loading="lazy"]:not(.fbm-img-loaded) {
    animation: none;
    background: #ececec;
  }
}