body {
  margin: 0;
  overflow: hidden;
  font-family: Arial, sans-serif;
  background: black;
  color: white;
  text-align: center;
}

/* Start Screen */
#startScreen {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.9);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 5;
}

#startScreen input {
  padding: 10px;
  font-size: 18px;
  margin: 10px;
}
#startScreen button {
  padding: 10px 20px;
  font-size: 18px;
  cursor: pointer;
}

/* Canvas overlay */
#output_canvas {
  position: fixed;
  top: 0; left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 1;
}

/* HUD */
#hud {
  position: fixed;
  top: 10px; left: 10px;
  display: flex;
  gap: 20px;
  font-size: 22px;
  z-index: 2;
}

#score, #timer {
  background: rgba(0,0,0,0.6);
  padding: 6px 12px;
  border-radius: 8px;
}

/* Game Over Popup */
#gameOverPopup {
  position: fixed;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0,0,0,0.9);
  padding: 20px 30px;
  border-radius: 10px;
  display: none;
  z-index: 10;
}
#gameOverPopup button {
  margin: 10px;
  padding: 10px 20px;
  font-size: 18px;
  cursor: pointer;
}