#myCanvas {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
}

form {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  background-color: rgba(240,240,240,0.75);
  border-radius: 0.1rem;
  border: solid white 1px;
}

input {
  display: block;
  width: 10rem;
  margin: 2rem;
}

#backdrop {
  z-index: -10;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 22rem;
  height: 22rem;
  background-image: radial-gradient(rgba(0,0,0,0.2), rgba(0,0,0,0.05) 25%, rgba(0,0,0,0) 70%);
}