@keyframes showPowerBgStage {
  0% {
    background: rgba(255, 168, 42, 0);
    opacity: 0;
  }
  100% {
    background: rgba(236,100,100,0.8);
    opacity: 1;
  }
}
@keyframes hidePowerBgStage {
  0% {
    background: rgba(236,100,100,0.8);
    opacity: 1;
  }
  100% {
    background: rgba(255, 168, 42, 0);
    opacity: 0;
  }
}

.stage0 .powerful_img {
  animation: 1s showPowerBgStage;
  -webkit-animation: 1s showPowerBgStage;
  animation-fill-mode: forwards;
  -webkit-animation-fill-mode: forwards;
}
.stage1 .powerful_img {
  animation: 1s hidePowerBgStage;
  -webkit-animation: 1s hidePowerBgStage;
  animation-fill-mode: forwards;
  -webkit-animation-fill-mode: forwards;
  
}
.powerful_img {
  z-index: 10;
}