* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #05070c;
  color: #e8ecf2;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

#hud {
  position: fixed;
  top: 12px;
  left: 12px;
  right: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
  font-size: 15px;
  letter-spacing: 0.5px;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
  z-index: 10;
}

#crosshair {
  position: fixed;
  left: 50%;
  top: 50%;
  width: 12px;
  height: 12px;
  margin-left: -6px;
  margin-top: -6px;
  border: 2px solid rgba(255, 255, 255, 0.75);
  border-radius: 50%;
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.25);
  z-index: 9;
  pointer-events: none;
}

#overlay,
#game-over {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 30% 30%, rgba(21, 40, 77, 0.6), rgba(4, 7, 12, 0.9));
  color: #e8ecf2;
  z-index: 20;
  text-align: center;
}

#overlay h1 {
  font-size: 32px;
  margin-bottom: 12px;
  letter-spacing: 1px;
}

#overlay p {
  opacity: 0.88;
}

#overlay.hidden,
#game-over.hidden {
  display: none;
}

#game-over .panel {
  background: rgba(10, 14, 24, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 20px 28px;
  border-radius: 10px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
}

#game-over h2 {
  margin-bottom: 8px;
  font-size: 26px;
}

#game-over p {
  margin-top: 4px;
}

canvas {
  display: block;
}