html {
  height: 100%;
  overflow: hidden;
}
body {
  margin: 0;
  padding: 0;
  perspective: 1px;
  transform-style: preserve-3d;
  overflow-y: scroll;
  overflow-x: hidden;
}
header {
  box-sizing: border-box;
  height: 100vh;
  padding-top: 20%;
  transform-style: inherit;
  width: 100vw;
}
header::before {
  content: '';
  display: block;
  position: absolute;
  left: 0;
  right: 0;
  top: -20%;
  bottom: 0;
  z-index: -1;
  transform-origin: center;
  min-height: 100%;
  background-image: url(./img/bg.png);
  background-repeat: no-repeat;
  /* background-size: cover; */

  transform: translateZ(-1px) scale(2);
}