:root {
  --royal: #15318E;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--royal);
  overflow: hidden;
  overscroll-behavior: none;
}

#scene {
  display: block;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  touch-action: none; /* let us own pointer gestures, no scroll/zoom */
}

/* Accessible heading for screen readers / SEO; not shown visually. */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  overflow: hidden;
  white-space: nowrap;
}