:root { color-scheme: dark; }
* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { height: 100%; overflow: hidden; background: #04060d; overscroll-behavior: none; }
#scene { position: fixed; inset: 0; width: 100%; height: 100%; display: block; touch-action: none; }
#hud { position: fixed; inset: 0; pointer-events: none; font-family: ui-monospace, 'SF Mono', Menlo, monospace; }
#hud-title {
  position: absolute; top: calc(env(safe-area-inset-top, 0px) + 18px); left: 50%; transform: translateX(-50%);
  color: #9be8ff; letter-spacing: .45em; font-size: 13px; white-space: nowrap;
  text-shadow: 0 0 12px #00e5ff, 0 0 32px #0066ff;
  transition: opacity 2s ease;
}
#hud-title.gone { opacity: 0; }
#hud-hint {
  position: absolute; bottom: calc(env(safe-area-inset-bottom, 0px) + 22px); left: 50%; transform: translateX(-50%);
  color: rgba(190,225,255,.66); font-size: 11px; letter-spacing: .18em; white-space: nowrap;
  transition: opacity 2s ease;
}
#hud-hint.gone { opacity: 0; }
#hud-crosshair {
  position: absolute; left: 50%; top: 50%; width: 3px; height: 3px; margin: -1.5px;
  border-radius: 50%; background: rgba(160,230,255,.7); box-shadow: 0 0 6px rgba(0,229,255,.8);
}
#hud-vignette {
  position: absolute; inset: 0;
  background: radial-gradient(ellipse at center, transparent 55%, rgba(2,4,10,.55) 100%);
}