html, body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #000;
}

#wrapper {
  position: relative;
  width: 100vw;
  height: 100vh;
  background: transparent;
  overflow: hidden;
}

#background {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
}

.valve {
  position: absolute;
  z-index: 10;
  pointer-events: none;
}