* { box-sizing: border-box; }
.video-background {
  background: #000;
  position: fixed;
  top: 0; right: 0; bottom: 0; left: 0;
  z-index: -99;
}
.video-foreground,
.video-background iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

div#formulaireLanding {
    background-color: deepskyblue;
    padding: 20px;
    border-radius: 30px;
}