: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;
  }
}

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

html, body {
  height: 100%;
  width: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Pretendard', 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100dvh;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

#app {
  width: 100%;
  max-width: 480px;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  background-color: var(--bg-primary);
}

/* ===================== SCREENS ===================== */
.screen {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px 20px;
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: auto;
}

.screen.hidden {
  opacity: 0;
  pointer-events: none;
  transform: scale(0.97);
}

/* ===================== OVERLAY BACKDROP ===================== */
.overlay-screen {
  background: var(--overlay-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 100;
}

/* ===================== START SCREEN ===================== */
#start-screen {
  gap: 32px;
}

.start-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.game-icon {
  font-size: 64px;
  line-height: 1;
  filter: drop-shadow(0 4px 24px rgba(59,130,246,0.4));
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-8px); }
}

.title-gradient {
  font-size: 40px;
  font-weight: 800;
  letter-spacing: 6px;
  background: linear-gradient(135deg, #3B82F6 0%, #8B5CF6 50%, #EC4899 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
}

.subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  letter-spacing: 2px;
  text-transform: uppercase;
  font-weight: 500;
}

.start-buttons {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 280px;
}

/* ===================== BUTTONS ===================== */
.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s, border-color 0.15s;
  width: 100%;
  letter-spacing: 0.5px;
}

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

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.btn-primary:active {
  background: #2563eb;
}

.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--text-secondary);
}

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

.btn-icon {
  font-size: 18px;
}

/* ===================== LEVEL SELECT ===================== */
#level-select-screen {
  gap: 20px;
  overflow-y: auto;
  justify-content: flex-start;
  padding-top: 40px;
  padding-bottom: 40px;
}

.screen-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 1px;
}

.level-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  width: 100%;
}

.level-card {
  aspect-ratio: 1;
  background: var(--bg-secondary);
  border: 1.5px solid var(--border);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, transform 0.1s;
  gap: 4px;
  padding: 8px 4px;
}

.level-card:active {
  transform: scale(0.95);
  background: var(--bg-tertiary);
}

.level-card.completed {
  border-color: var(--accent);
  background: rgba(59,130,246,0.08);
}

.level-card.current {
  border-color: #8B5CF6;
  background: rgba(139,92,246,0.08);
}

.level-num {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.level-star {
  font-size: 12px;
  min-height: 14px;
}

.level-best {
  font-size: 10px;
  color: var(--text-muted);
  font-weight: 500;
}

/* ===================== GAME SCREEN ===================== */
#game-screen {
  padding: 16px 12px 12px;
  gap: 0;
  justify-content: flex-start;
}

.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  margin-bottom: 12px;
}

.header-left, .header-right {
  display: flex;
  align-items: center;
  gap: 6px;
}

.level-label {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.level-number {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
}

.move-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
}

.move-count {
  font-size: 22px;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
}

.move-label {
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  font-weight: 500;
}

.best-label {
  font-size: 11px;
  color: var(--text-muted);
}

.best-value {
  font-size: 11px;
  color: var(--accent);
  font-weight: 600;
}

.icon-btn {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text-primary);
  font-size: 16px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, transform 0.1s;
  font-family: inherit;
  flex-shrink: 0;
}

.icon-btn:active {
  transform: scale(0.92);
  background: var(--btn-active);
}

/* ===================== CANVAS BOARD ===================== */
#board-wrapper {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
}

#game-canvas {
  display: block;
  border-radius: 12px;
  image-rendering: pixelated;
  touch-action: none;
}

/* ===================== D-PAD ===================== */
.dpad-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
  width: 100%;
}

.dpad-row {
  display: flex;
  gap: 8px;
  align-items: center;
}

.dpad-row-middle {
  display: flex;
  gap: 8px;
  align-items: center;
}

.dpad-btn {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text-primary);
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.1s, transform 0.08s;
  font-family: inherit;
  -webkit-tap-highlight-color: transparent;
}

.dpad-btn:active {
  transform: scale(0.92);
  background: var(--btn-active);
}

.dpad-spacer {
  width: 52px;
  height: 52px;
  pointer-events: none;
}

.action-row {
  display: flex;
  gap: 10px;
  width: 100%;
  justify-content: center;
  margin-top: 4px;
}

.action-btn {
  flex: 1;
  max-width: 140px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: background 0.1s, transform 0.08s;
  font-family: inherit;
  letter-spacing: 0.3px;
  -webkit-tap-highlight-color: transparent;
}

.action-btn:active {
  transform: scale(0.96);
  background: var(--btn-active);
  color: var(--text-primary);
}

/* ===================== VICTORY SCREEN ===================== */
#victory-screen {
  gap: 24px;
  text-align: center;
}

.victory-icon {
  font-size: 72px;
  animation: bounce 0.6s ease;
}

@keyframes bounce {
  0% { transform: scale(0); opacity: 0; }
  60% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(1); }
}

.victory-title {
  font-size: 28px;
  font-weight: 800;
  background: linear-gradient(135deg, #3B82F6 0%, #8B5CF6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.victory-stats {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px 28px;
  width: 100%;
  max-width: 280px;
}

.stat-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.stat-label {
  font-size: 14px;
  color: var(--text-secondary);
  font-weight: 500;
}

.stat-value {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-value.new-best {
  color: #F59E0B;
}

.new-best-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 6px;
  background: rgba(245,158,11,0.15);
  color: #F59E0B;
  letter-spacing: 0.5px;
  margin-left: 6px;
}

.victory-buttons {
  display: flex;
  flex-direction: column;
  gap: 10px;
  width: 100%;
  max-width: 280px;
}

/* ===================== ALL CLEAR SCREEN ===================== */
#allclear-screen {
  gap: 28px;
  text-align: center;
}

.allclear-icon {
  font-size: 80px;
  animation: spin-in 0.8s ease;
}

@keyframes spin-in {
  0% { transform: rotate(-180deg) scale(0); opacity: 0; }
  100% { transform: rotate(0deg) scale(1); opacity: 1; }
}

.allclear-title {
  font-size: 32px;
  font-weight: 800;
  background: linear-gradient(135deg, #F59E0B 0%, #EC4899 50%, #8B5CF6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 2px;
}

.allclear-sub {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===================== SCROLLBAR ===================== */
::-webkit-scrollbar {
  width: 4px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

/* ===================== RESPONSIVE ADJUSTMENTS ===================== */
@media (max-height: 700px) {
  .dpad-btn {
    width: 46px;
    height: 46px;
    font-size: 18px;
  }
  .action-btn {
    height: 38px;
    font-size: 12px;
  }
  .game-header {
    margin-bottom: 8px;
  }
  .dpad-container {
    gap: 6px;
    margin-top: 6px;
  }
}

@media (max-height: 600px) {
  .dpad-btn {
    width: 40px;
    height: 40px;
    font-size: 16px;
  }
  .dpad-container {
    gap: 4px;
    margin-top: 4px;
  }
}