:root {
  --bg-primary: #0D1117;
  --bg-secondary: #161B22;
  --bg-tertiary: #21262D;
  --text-primary: #F0F6FC;
  --text-secondary: #8B949E;
  --text-muted: #484F58;
  --accent: #3B82F6;
  --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;
    --border: #D0D7DE;
    --btn-bg: #E9ECF0;
    --btn-active: #D0D7DE;
    --overlay-bg: rgba(255, 255, 255, 0.9);
    --board-bg: #F0F2F5;
  }
}

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

html,
body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Pretendard', 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

#app {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100dvh;
  background: var(--bg-primary);
}

#game-wrapper {
  position: relative;
  width: 100%;
  max-width: 480px;
  height: 100dvh;
  background: var(--board-bg);
  overflow: hidden;
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
}

#game-canvas {
  display: block;
  width: 100%;
  height: 100%;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

/* ── Overlays ── */
.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--overlay-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 10;
  padding: 32px 24px;
  gap: 0;
  transition: opacity 0.3s ease;
}

.overlay.hidden {
  display: none;
}

/* ── Title ── */
.game-title {
  font-size: clamp(48px, 14vw, 72px);
  font-weight: 900;
  letter-spacing: -2px;
  background: linear-gradient(135deg, var(--accent) 0%, #a78bfa 50%, #f472b6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
  line-height: 1;
}

.game-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-bottom: 48px;
}

/* ── Score display ── */
.score-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin-bottom: 40px;
}

.score-label {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 2px;
  text-transform: uppercase;
}

.score-value {
  font-size: clamp(32px, 10vw, 48px);
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
}

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

.high-score-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 48px;
}

.high-score-row .hs-label {
  color: var(--text-muted);
  letter-spacing: 1px;
  text-transform: uppercase;
  font-size: 11px;
}

.high-score-row .hs-value {
  color: var(--accent);
  font-weight: 700;
}

/* ── Buttons ── */
.btn-primary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  max-width: 260px;
  padding: 16px 24px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.1s ease, opacity 0.15s ease, box-shadow 0.15s ease;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 24px rgba(59, 130, 246, 0.35);
}

.btn-primary:active {
  transform: scale(0.97);
  opacity: 0.9;
}

.btn-secondary {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 260px;
  padding: 13px 24px;
  background: var(--btn-bg);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s ease, background 0.15s ease;
  margin-top: 12px;
  letter-spacing: 0.3px;
}

.btn-secondary:active {
  background: var(--btn-active);
  transform: scale(0.97);
}

/* ── HUD ── */
#hud {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  z-index: 5;
  pointer-events: none;
}

.hud-score {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.5);
}

.hud-best {
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 1px;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.5);
}

.hud-best span {
  color: var(--accent);
  font-weight: 700;
}

/* ── Instructions ── */
.instructions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin-bottom: 40px;
}

.inst-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--text-secondary);
}

.inst-icon {
  width: 28px;
  height: 28px;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
}

/* ── Divider ── */
.divider {
  width: 100%;
  max-width: 260px;
  height: 1px;
  background: var(--border);
  margin: 24px 0;
}

/* ── New record badge ── */
.new-record-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--accent), #a78bfa);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 16px;
}

.new-record-badge.hidden {
  display: none;
}

/* ── Milestone toast ── */
#milestone-toast {
  position: absolute;
  top: 60px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  background: var(--accent);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  padding: 8px 18px;
  border-radius: 20px;
  letter-spacing: 0.5px;
  opacity: 0;
  pointer-events: none;
  z-index: 6;
  white-space: nowrap;
  transition: opacity 0.25s ease, transform 0.25s ease;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.4);
}

#milestone-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ── Pause button ── */
#pause-btn {
  position: absolute;
  top: 10px;
  right: 16px;
  width: 36px;
  height: 36px;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 6;
  pointer-events: all;
  transition: background 0.15s ease;
  font-size: 14px;
  color: var(--text-secondary);
}

#pause-btn:active {
  background: var(--btn-active);
}

/* ── Pause overlay extra styles ── */
#pause-overlay .pause-title {
  font-size: 28px;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 8px;
  letter-spacing: -1px;
}

#pause-overlay .pause-score {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

#pause-overlay .pause-score span {
  color: var(--accent);
  font-weight: 700;
}