.preloader {
  position: fixed;
  inset: 0;
  background: rgba(255,255,255,0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity 0.3s ease;
}
.dark .preloader { background: rgba(17,24,39,0.95); }