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

body {
  background: #000;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  font-family: 'Courier New', monospace;
  color: #fff;
}

#game-container {
  position: relative;
}

#game {
  background: #000010;
  display: block;
  border: 2px solid #1a4a1a;
  box-shadow: 0 0 30px rgba(0, 255, 65, 0.25);
}

#overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 10, 0.85);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 20px;
  text-align: center;
  z-index: 10;
}

#overlay.hidden {
  display: none;
}

#overlay h1 {
  color: #00ff41;
  font-size: 42px;
  letter-spacing: 8px;
  text-shadow: 0 0 20px rgba(0, 255, 65, 0.8);
  animation: pulse 2s ease-in-out infinite;
}

#overlay p {
  color: #9fd99f;
  font-size: 14px;
  line-height: 1.8;
}

#overlay .key {
  display: inline-block;
  background: #111a11;
  border: 1px solid #00ff41;
  border-radius: 4px;
  padding: 2px 8px;
  margin: 0 4px;
  color: #00ff41;
}

#start-btn {
  margin-top: 10px;
  font-family: inherit;
  font-size: 20px;
  letter-spacing: 4px;
  padding: 12px 40px;
  background: transparent;
  color: #00ff41;
  border: 2px solid #00ff41;
  cursor: pointer;
  transition: all 0.2s;
}

#start-btn:hover {
  background: #00ff41;
  color: #000;
  box-shadow: 0 0 25px rgba(0, 255, 65, 0.7);
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}