Make sure the hero can contain the absolutely positioned canvas
#hero {
  position: relative;
  overflow: hidden;
  min-height: 100vh;
}

/* Canvas sits behind content, full-bleed */
#hero-web {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 1;          /* Behind the container (which uses z-index:2 inline) */
  display: block;      /* Removes inline gap ghosting on some browsers */
  pointer-events: none;/* Let right-click & mousemove go through to hero */
}