*, *::before, *::after { box-sizing: border-box; }

html, body { height: 100%; margin: 0; }

body {
  display: grid;
  place-items: center;
  font-family: system-ui, -apple-system, sans-serif;
  color: #fff;
  background: #0e1a14;
}

main {
  position: relative;
  min-height: 100svh;
  width: 100%;
  display: grid;
  place-items: center;
  isolation: isolate;
  padding: 2rem;
}

.fondo {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
}
.fondo img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  opacity: 0;
  animation: ciclo 60s infinite;
  animation-timing-function: linear;
  will-change: opacity;
}
.fondo .img-1 { animation-delay:  0s; }
.fondo .img-2 { animation-delay: 12s; }
.fondo .img-3 { animation-delay: 24s; }
.fondo .img-4 { animation-delay: 36s; }
.fondo .img-5 { animation-delay: 48s; }

@keyframes ciclo {
  0%     { opacity: 0; }
  3.33%  { opacity: 1; }
  20%    { opacity: 1; }
  23.33% { opacity: 0; }
  100%   { opacity: 0; }
}

.overlay {
  position: fixed;
  inset: 0;
  z-index: -1;
  background: rgba(0, 0, 0, 0.28);
  pointer-events: none;
}

.sello {
  display: block;
  margin-inline: auto;
  width: clamp(180px, 30vw, 270px);
  height: auto;
  border-radius: 8px;
  filter: drop-shadow(0 4px 24px rgba(0, 0, 0, 0.4));
  justify-self: center;
  align-self: center;
}

@media (prefers-color-scheme: light) {
  .overlay { background: rgba(255, 255, 255, 0.08); }
}

@media (prefers-reduced-motion: reduce) {
  .fondo img { animation: none; }
  .fondo .img-1 { opacity: 1; }
  .fondo .img-2,
  .fondo .img-3,
  .fondo .img-4,
  .fondo .img-5 { opacity: 0; }
}