body {
  margin: 0;
  overflow: hidden;
  /* subtle radial gradient for a bit more atmosphere */
  background: radial-gradient(#222, #000);
}

canvas {
  display: block;
  margin: auto;
  background-color: #111;
  /* faint diagonal pattern for visual interest */
  background-image: repeating-linear-gradient(
    45deg,
    rgba(255, 255, 255, 0.05) 0,
    rgba(255, 255, 255, 0.05) 10px,
    transparent 10px,
    transparent 20px
  );
}

#scoreboard {
  position: absolute;
  top: 10px;
  left: 10px;
  color: white;
  font-family: sans-serif;
}

.overlay {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0, 0, 0, 0.7);
  color: white;
  font-family: sans-serif;
  padding: 20px 30px;
  border-radius: 10px;
  font-size: 32px;
  text-align: center;
}

#loginOverlay {
  display: flex;
  flex-direction: column;
}
#loginOverlay input,
#loginOverlay button {
  margin-top: 10px;
  font-size: 16px;
}