html,
body {
  width: 100%;
  min-height: 100%;
  margin: 0;
  background: transparent;
}

body {
  display: grid;
  min-height: 100dvh;
  place-items: center;
  padding: clamp(1rem, 4vw, 3rem);
  box-sizing: border-box;
}

.card {
  width: min(34rem, 100%);
  background: transparent;
  animation: transparencyCycle 10s steps(1, end) infinite;
}

.card img {
  display: block;
  width: 100%;
  height: auto;
  background: transparent;
}

@keyframes transparencyCycle {
  0%,
  49.999% {
    opacity: 1;
    visibility: visible;
  }

  50%,
  99.999% {
    opacity: 0;
    visibility: hidden;
  }
}