:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #14141f;
  --bg-tertiary: #1e1e2e;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent: #00d4ff;
  --accent-secondary: #00ff88;
  --danger: #ff4466;
  --focus-ring: #00d4ff;
  --focus-glow: rgba(0, 212, 255, 0.4);
  --radius-md: 12px;
}

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

html, body {
  width: 600px;
  height: 600px;
  overflow: hidden;
  background: #000;
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

#app {
  width: 100%;
  height: 100%;
  position: relative;
}

.screen {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  flex-direction: column;
}

.screen.hidden {
  display: none;
}

.screen-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: 40px;
  background: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary));
}

h1 {
  font-size: 48px;
  font-weight: bold;
  margin-bottom: 40px;
  color: var(--accent);
  text-shadow: 0 0 20px rgba(0, 212, 255, 0.5);
  letter-spacing: 2px;
}

.button-group {
  display: flex;
  flex-direction: column;
  gap: 20px;
  width: 100%;
  max-width: 300px;
}

button.focusable {
  padding: 16px 24px;
  background: var(--bg-tertiary);
  border: 2px solid var(--text-secondary);
  color: var(--text-primary);
  font-size: 18px;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.15s ease;
  outline: none;
  min-height: 60px;
}

button.focusable:hover {
  background: var(--bg-secondary);
  border-color: var(--accent);
}

button.focusable:focus {
  border-color: var(--focus-ring);
  box-shadow: 0 0 20px var(--focus-glow);
  background: var(--bg-secondary);
}

.focusable {
  transition: all 0.15s ease;
  border: 2px solid transparent;
  outline: none;
}

.focusable:focus {
  border-color: var(--focus-ring);
  box-shadow: 0 0 20px var(--focus-glow);
}

.hidden {
  display: none !important;
}

.score-display {
  font-size: 24px;
  color: var(--text-primary);
  margin: 20px 0;
}

.score-display.large {
  font-size: 36px;
  font-weight: bold;
  color: var(--accent-secondary);
  margin: 30px 0;
}

#scoreValue, #livesValue, #goScore, #winScore {
  color: var(--accent);
  font-weight: bold;
}

.game-hud {
  position: absolute;
  top: 20px;
  left: 20px;
  right: 20px;
  display: flex;
  justify-content: space-between;
  color: var(--text-primary);
  font-size: 18px;
  font-weight: bold;
  z-index: 10;
  text-shadow: 0 0 10px rgba(0, 212, 255, 0.3);
}

.game-hint {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-secondary);
  font-size: 16px;
  text-align: center;
  z-index: 10;
  animation: pulse 1.5s infinite;
}

.game-hint.hidden {
  display: none;
}

@keyframes pulse {
  0%, 100% {
    opacity: 0.6;
  }
  50% {
    opacity: 1;
  }
}

.about-text {
  max-width: 450px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.8;
  margin-bottom: 40px;
}

.about-text p {
  margin-bottom: 16px;
}

#gameCanvas {
  display: block;
  width: 600px;
  height: 600px;
  background: #000;
}