html, body { margin: 0; height: 100%; background: #121419; color: #c9ced8; font: 14px system-ui, sans-serif; overflow: hidden; }
#scene { display: block; width: 100%; height: 100%; cursor: grab; touch-action: none; }
#scene:active { cursor: grabbing; }
#fallback { position: fixed; inset: 0; display: grid; place-items: center; margin: 0; }
#fallback[hidden] { display: none; }