:root {
  --hud-font: 'Press Start 2P', sans-serif;
  --hud-color: #e0e0e0;
  --hud-shadow: 1px 1px 2px rgba(0, 0, 0, 0.7);
  --background-gradient: radial-gradient(circle at top, #2b2b2b, #000000);
  --accent-green: #00ff99;
  --accent-purple: #8e2bff;
  --overlay-bg: rgba(20, 20, 20, 0.8);
  --button-bg: var(--accent-purple);
  --button-color: #ffffff;
  --button-border: var(--accent-green);
  --button-hover-bg: var(--accent-green);
  --button-hover-color: #000000;
  --button-focus-outline: rgba(0, 255, 153, 0.8);
}

body {
  margin: 0;
  background: var(--background-gradient);
  color: var(--hud-color);
  font-family: var(--hud-font);
}

#game-container {
  position: relative;
  width: 100%;
  max-width: 800px;
  margin: 40px auto;
  overflow: hidden;
  box-shadow: 0 0 20px var(--accent-purple);
  border: 2px solid var(--accent-green);
  background-color: rgba(0, 0, 0, 0.3);
}

#game-canvas {
  display: block;
  width: 100%;
  height: auto;
  background-color: transparent;
  border-bottom: 2px solid var(--accent-green);
}


#score-container span,
#lives-container span,
#level-container span {
  color: var(--accent-green);
}

.hud {
  pointer-events: none;
  font-family: var(--hud-font);
  color: var(--hud-color);
  text-shadow: var(--hud-shadow);
}

.hud__element {
  position: absolute;
  font-size: 14px;
}


#ui-overlay {
  position: absolute;
  top: 10px;
  left: 10px;
  display: flex;
  gap: 40px;
  pointer-events: none;
  font-family: var(--hud-font);
  color: var(--hud-color);
  text-shadow: var(--hud-shadow);
}

.hud__score,
.hud__lives,
.hud__level {
  position: static;
}

.hud__lives-icon {
  width: 20px;
  height: 20px;
  background-size: contain;
  background-repeat: no-repeat;
  margin-right: 6px;
}

.hud__ammo {
  bottom: 10px;
  left: 10px;
}

.overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--overlay-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--hud-color);
  font-family: var(--hud-font);
  text-align: center;
  z-index: 100;
  padding: 20px;
  backdrop-filter: blur(2px);
}

.overlay--hidden {
  display: none;
}

.overlay__title {
  font-size: 32px;
  margin-bottom: 20px;
  color: var(--accent-green);
  text-shadow: 0 0 10px var(--accent-purple);
}

.overlay__subtitle {
  font-size: 16px;
  margin-bottom: 20px;
  color: var(--hud-color);
}

.overlay__menu {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.overlay__button {
  margin: 8px 0;
  padding: 10px 20px;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  background-color: var(--button-bg);
  color: var(--button-color);
  border: 2px solid var(--button-border);
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
  pointer-events: auto;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 8px var(--accent-purple);
}

.overlay--grayscale {
  filter: grayscale(1);
}

.overlay__button--gray {
  background-color: #555;
  border-color: #888;
  color: #f0f0f0;
}

.overlay__button--large {
  font-size: 18px;
  padding: 16px 32px;
}

.overlay__button:hover,
.overlay__button:focus {
  background-color: var(--button-hover-bg);
  color: var(--button-hover-color);
  box-shadow: 0 0 12px var(--accent-green);
}

.overlay__button:focus {
  outline: none;
  box-shadow: 0 0 12px var(--accent-green), 0 0 0 3px var(--button-focus-outline);
}

@media (max-width: 600px) {
  .hud__element {
    font-size: 12px;
  }
  .overlay__title {
    font-size: 24px;
  }
  .overlay__subtitle {
    font-size: 14px;
  }
  .overlay__button {
    padding: 12px 16px;
    font-size: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .overlay__button {
    transition: none;
  }
}