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

body {
  background: #000;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  overflow: hidden;
  font-family: 'Courier New', monospace;
  color: #ffcc00;
}

#game-container {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

#gameCanvas {
  display: block;
  background: #0a0a2e;
  border: 2px solid #333;
  image-rendering: pixelated;
  touch-action: none;
}

.overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  background: rgba(0, 0, 0, 0.85);
  z-index: 10;
}

.overlay.hidden {
  display: none;
}

#overlay-content {
  text-align: center;
  padding: 40px;
}

#overlay-content h1 {
  font-size: 48px;
  color: #00ff88;
  text-shadow: 0 0 20px #00ff88, 0 0 40px #00ff88;
  margin-bottom: 10px;
  letter-spacing: 4px;
}

#overlay-content h2 {
  font-size: 20px;
  color: #ffcc00;
  margin-bottom: 40px;
  font-weight: normal;
}

#overlay-content .menu-item {
  display: block;
  font-size: 22px;
  color: #aaa;
  margin: 12px 0;
  cursor: pointer;
  padding: 8px 20px;
  transition: all 0.15s;
  font-family: 'Courier New', monospace;
  background: none;
  border: 1px solid transparent;
  width: 300px;
  margin-left: auto;
  margin-right: auto;
}

#overlay-content .menu-item:hover,
#overlay-content .menu-item.selected {
  color: #00ff88;
  border-color: #00ff88;
  text-shadow: 0 0 10px #00ff88;
}

#overlay-content .menu-item .key-hint {
  color: #666;
  font-size: 14px;
}

#overlay-content .score-display {
  font-size: 36px;
  color: #ffcc00;
  margin: 20px 0;
  text-shadow: 0 0 10px #ffcc00;
}

#overlay-content .highscore-list {
  margin: 20px auto;
  text-align: left;
  max-width: 300px;
}

#overlay-content .highscore-list .hs-entry {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  border-bottom: 1px solid #222;
  font-size: 16px;
}

#overlay-content .highscore-list .hs-entry .hs-name {
  color: #00ff88;
}

#overlay-content .highscore-list .hs-entry .hs-score {
  color: #ffcc00;
}

#overlay-content .controls-info {
  text-align: left;
  font-size: 14px;
  color: #888;
  line-height: 2;
  max-width: 400px;
  margin: 0 auto;
}

#overlay-content .controls-info span {
  color: #00ff88;
}

#overlay-content .difficulty-selector {
  margin: 20px 0;
  display: flex;
  justify-content: center;
  gap: 10px;
}

#overlay-content .diff-btn {
  padding: 8px 16px;
  font-size: 16px;
  font-family: 'Courier New', monospace;
  background: none;
  border: 1px solid #555;
  color: #888;
  cursor: pointer;
  transition: all 0.15s;
}

#overlay-content .diff-btn.active {
  border-color: #00ff88;
  color: #00ff88;
  text-shadow: 0 0 10px #00ff88;
}

#overlay-content .diff-btn:hover {
  border-color: #00ff88;
  color: #00ff88;
}

#overlay-content .subtitle {
  font-size: 14px;
  color: #666;
  margin-bottom: 30px;
}