.fullscreen-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  z-index: -1;
}
.fullscreen-bg__video,
.fullscreen-bg__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
body {
  margin: 0;
}