html, body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #050811;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

canvas { display: block; }

#hud {
  position: fixed;
  left: 16px;
  top: 16px;
  z-index: 10;
  max-width: min(620px, calc(100vw - 32px));
  padding: 14px 16px;
  border-radius: 16px;
  color: white;
  background: rgba(5, 8, 17, 0.72);
  backdrop-filter: blur(8px);
  box-shadow: 0 10px 32px rgba(0,0,0,0.35);
  line-height: 1.35;
}

#hud h1 { margin: 0 0 8px; font-size: 20px; }
#hud p { margin: 7px 0; font-size: 13px; }
#status { opacity: .88; }

#crosshair {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 9;
  color: rgba(255,255,255,.78);
  font-size: 28px;
  pointer-events: none;
  user-select: none;
}

.overlay {
  position: fixed;
  inset: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(2, 4, 10, .78);
}

.overlay.hidden { display: none; }
.overlay.visible { display: flex; }

.card {
  width: min(580px, calc(100vw - 32px));
  border-radius: 22px;
  padding: 26px 28px;
  background: rgba(242, 245, 252, .96);
  color: #101722;
  box-shadow: 0 25px 70px rgba(0,0,0,.45);
}

.card h1 { margin-top: 0; letter-spacing: .03em; }
button {
  border: 0;
  border-radius: 13px;
  padding: 13px 18px;
  font-size: 16px;
  font-weight: 800;
  cursor: pointer;
  background: #1b6fff;
  color: white;
}
button:hover { filter: brightness(1.06); }
.small { font-size: 13px; opacity: .78; }

body.xr-active #hud,
body.xr-active #crosshair { display: none; }