.hero_bg {
  width: 100%;
  height:100%;
  background-size: cover;
  background-image: url('/image/pc_back.jpg');
  position: relative;
}

.hero_image {
  width: 90%;
  height: 90%;
  background-size: cover;
  background-image: url('/image/pc_main.png');
  position: absolute;
  top: 0;
  left: 0
}