.boot {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: #0b2545;
  z-index: 9999;
}

.boot img {
  width: 150px;
  height: auto;
  animation: boot-pulse 1.6s ease-in-out infinite;
}

@keyframes boot-pulse {
  0%, 100% { opacity: .45; transform: scale(.97); }
  50% { opacity: 1; transform: scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  .boot img { animation: none; opacity: .85; }
}