.sfondoblur_c {
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  width: 100%;
 background:#b1b1b1 url('https://pixwork.it/sfondi/');background-attachment: fixed;background-clip: border-box;background-origin: padding-box;background-position-x: center;background-position-y:center;background-repeat: no-repeat;background-size: cover;
  z-index: -1;
}
#background-video {
  width: 100vw;
  height: 100vh;
  object-fit: cover;
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  z-index: -1;
}