.persiana-background {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background-size: cover;
  background-position: center center;
  z-index: 0;
}

.persiana-mask {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  display: flex;
  z-index: 9;
  pointer-events: none;
}

.persiana-mask .panel {
  flex: 1;
  transform: translateY(-100%);
  animation: drop 1s forwards;
}

@keyframes drop {
  to {
    transform: translateY(0%);
  }
}