:root {
  --bg-primary: #0D1117;
  --bg-secondary: #161B22;
  --bg-tertiary: #21262D;
  --text-primary: #F0F6FC;
  --text-secondary: #8B949E;
  --text-muted: #484F58;
  --accent: #3B82F6;
  --accent-glow: rgba(59, 130, 246, 0.3);
  --border: #30363D;
  --btn-bg: #21262D;
  --btn-active: #30363D;
  --overlay-bg: rgba(0, 0, 0, 0.85);
  --board-bg: #0A0E14;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F6F8FA;
    --bg-tertiary: #E9ECF0;
    --text-primary: #1B1E28;
    --text-secondary: #57606A;
    --text-muted: #8C959F;
    --accent: #3182F6;
    --accent-glow: rgba(49, 130, 246, 0.2);
    --border: #D0D7DE;
    --btn-bg: #E9ECF0;
    --btn-active: #D0D7DE;
    --overlay-bg: rgba(255, 255, 255, 0.9);
    --board-bg: #F0F2F5;
  }
}

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

html, body {
  height: 100%;
  overflow: hidden;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Pretendard', 'Segoe UI', Roboto, sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100dvh;
  position: relative;
}

#app {
  width: 100%;
  max-width: 480px;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  position: relative;
  background: var(--bg-secondary);
  overflow: hidden;
}

/* Header */
#header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px 8px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  gap: 8px;
}

.header-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 60px;
}

.stat-label {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.stat-value {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.stat-value.accent {
  color: var(--accent);
}

#lives-display {
  display: flex;
  gap: 4px;
  align-items: center;
  justify-content: center;
}

.life-icon {
  font-size: 14px;
  transition: opacity 0.3s;
}

.life-icon.lost {
  opacity: 0.2;
}

/* Canvas area */
#canvas-wrapper {
  flex: 1;
  position: relative;
  background: var(--board-bg);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

#gameCanvas {
  display: block;
  image-rendering: crisp-edges;
  image-rendering: pixelated;
}

/* Overlay screens */
.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  background: var(--overlay-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 10;
  padding: 24px;
  text-align: center;
  transition: opacity 0.3s ease;
}

.overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.overlay-title {
  font-size: clamp(32px, 10vw, 48px);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1;
  background: linear-gradient(135deg, #3B82F6, #8B5CF6, #EC4899);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.overlay-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 280px;
  line-height: 1.5;
}

.overlay-score-box {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 24px;
  min-width: 180px;
}

.overlay-score-label {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}

.overlay-score-value {
  font-size: 28px;
  font-weight: 800;
  color: var(--accent);
  margin-top: 2px;
}

.overlay-best {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 32px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s, box-shadow 0.15s;
  min-width: 160px;
  touch-action: manipulation;
}

.btn:hover {
  background: var(--btn-active);
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 0 20px var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent);
  filter: brightness(1.1);
}

/* High scores panel */
.scores-panel {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 20px;
  width: 100%;
  max-width: 260px;
}

.scores-panel-title {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  margin-bottom: 8px;
}

.score-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 0;
  font-size: 13px;
  border-bottom: 1px solid var(--border);
}

.score-row:last-child {
  border-bottom: none;
}

.score-row .rank {
  color: var(--text-muted);
  font-weight: 600;
  width: 20px;
}

.score-row .score-val {
  color: var(--text-primary);
  font-weight: 700;
}

.score-row .score-level {
  color: var(--text-secondary);
  font-size: 11px;
}

/* Controls hint */
.controls-hint {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: -8px;
}

/* Level badge */
.level-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 4px 10px;
  min-width: 50px;
}

/* Particle canvas */
#particleCanvas {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 1;
}

/* Footer controls */
#footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 8px 16px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.ctrl-btn {
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-secondary);
  font-size: 12px;
  font-family: inherit;
  font-weight: 600;
  padding: 6px 14px;
  cursor: pointer;
  touch-action: manipulation;
  transition: background 0.1s, color 0.1s;
}

.ctrl-btn:hover {
  background: var(--btn-active);
  color: var(--text-primary);
}

.ctrl-btn:active {
  transform: scale(0.96);
}

/* Animations */
@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 8px var(--accent-glow); }
  50% { box-shadow: 0 0 24px var(--accent-glow), 0 0 48px var(--accent-glow); }
}

@keyframes float-in {
  from { opacity: 0; transform: translateY(20px) scale(0.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.overlay:not(.hidden) {
  animation: float-in 0.35s ease forwards;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%       { transform: translateX(-8px); }
  40%       { transform: translateX(8px); }
  60%       { transform: translateX(-5px); }
  80%       { transform: translateX(5px); }
}

.shake {
  animation: shake 0.4s ease;
}

/* Score popup */
.score-popup {
  position: absolute;
  font-size: 16px;
  font-weight: 800;
  color: var(--accent);
  pointer-events: none;
  z-index: 5;
  animation: score-float 0.8s ease forwards;
  text-shadow: 0 0 8px var(--accent-glow);
}

@keyframes score-float {
  0%   { opacity: 1; transform: translateY(0) scale(1); }
  100% { opacity: 0; transform: translateY(-48px) scale(1.2); }
}