/* ============================================================
   DESIGN TOKENS
   ============================================================ */
: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;

  /* Number colors */
  --num-1: #3B82F6;
  --num-2: #22C55E;
  --num-3: #EF4444;
  --num-4: #8B5CF6;
  --num-5: #F97316;
  --num-6: #06B6D4;
  --num-7: #EC4899;
  --num-8: #94A3B8;
}

@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;

    --num-1: #1D4ED8;
    --num-2: #15803D;
    --num-3: #DC2626;
    --num-4: #7C3AED;
    --num-5: #EA580C;
    --num-6: #0891B2;
    --num-7: #DB2777;
    --num-8: #64748B;
  }
}

/* ============================================================
   RESET & BASE
   ============================================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

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

/* ============================================================
   OVERLAYS
   ============================================================ */
.overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--overlay-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  padding: 24px;
  animation: fadeIn 0.25s ease;
}

.overlay.hidden {
  display: none;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

.overlay-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  width: 100%;
  max-width: 320px;
  animation: slideUp 0.3s ease;
}

/* ============================================================
   GAME TITLE (gradient)
   ============================================================ */
.game-title {
  font-size: 64px;
  font-weight: 900;
  letter-spacing: 0.12em;
  background: linear-gradient(135deg, #3B82F6, #8B5CF6, #EC4899);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  text-align: center;
}

.overlay-icon {
  font-size: 56px;
  line-height: 1;
}

.overlay-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
}

.overlay-desc {
  font-size: 15px;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.5;
}

.overlay-stats {
  font-size: 14px;
  color: var(--text-muted);
  min-height: 20px;
}

/* Win stats */
.win-stats {
  width: 100%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

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

.win-stat-value {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.new-record {
  font-size: 18px;
  font-weight: 700;
  color: #F59E0B;
  text-align: center;
  animation: pulse 0.8s ease infinite alternate;
}

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

@keyframes pulse {
  from { opacity: 0.7; transform: scale(0.97); }
  to   { opacity: 1;   transform: scale(1.03); }
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn-primary {
  width: 100%;
  padding: 14px 24px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s, box-shadow 0.15s;
  box-shadow: 0 0 0 0 var(--accent-glow);
  font-family: inherit;
}

.btn-primary:hover {
  opacity: 0.92;
  box-shadow: 0 0 16px var(--accent-glow);
}

.btn-primary:active {
  transform: scale(0.97);
  opacity: 0.85;
}

/* ============================================================
   GAME LAYOUT
   ============================================================ */
.game-wrapper {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 480px;
  height: 100dvh;
  padding: env(safe-area-inset-top, 0) env(safe-area-inset-right, 0) env(safe-area-inset-bottom, 0) env(safe-area-inset-left, 0);
}

/* ============================================================
   HEADER
   ============================================================ */
.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px 12px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-secondary);
  flex-shrink: 0;
}

.header-title {
  font-size: 22px;
  font-weight: 900;
  letter-spacing: 0.1em;
  background: linear-gradient(135deg, #3B82F6, #8B5CF6, #EC4899);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-stats {
  display: flex;
  gap: 10px;
  align-items: center;
}

.stat-pill {
  display: flex;
  align-items: center;
  gap: 5px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 12px;
  min-width: 64px;
}

.stat-icon {
  font-size: 14px;
  line-height: 1;
}

.stat-value {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
  min-width: 28px;
}

/* ============================================================
   BOARD AREA
   ============================================================ */
.board-container {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--board-bg);
  overflow: hidden;
  padding: 12px;
}

.board {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
  gap: 3px;
  width: min(calc(100vw - 24px), calc(100dvh - 160px), 420px);
  aspect-ratio: 1;
}

/* ============================================================
   CELLS
   ============================================================ */
.cell {
  aspect-ratio: 1;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(11px, 2.8vw, 16px);
  font-weight: 800;
  cursor: pointer;
  transition: background 0.1s, transform 0.08s, box-shadow 0.1s;
  position: relative;
  border: 1px solid transparent;
  -webkit-tap-highlight-color: transparent;
}

/* Hidden (unrevealed) */
.cell.hidden {
  background: var(--btn-bg);
  border-color: var(--border);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.07);
}

.cell.hidden:active {
  transform: scale(0.91);
  background: var(--btn-active);
}

/* Revealed (empty) */
.cell.revealed {
  background: var(--board-bg);
  border-color: var(--border);
  cursor: default;
}

/* Flagged */
.cell.flagged {
  background: var(--btn-bg);
  border-color: var(--border);
  position: relative;
}

.cell.flagged::after {
  content: '🚩';
  font-size: clamp(10px, 2.5vw, 15px);
}

/* Revealed mine (game over) */
.cell.mine-hit {
  background: #7F1D1D;
  border-color: #EF4444;
  animation: shake 0.35s ease;
}

.cell.mine-hit::after {
  content: '💣';
  font-size: clamp(10px, 2.5vw, 14px);
}

/* Other mines revealed on game over */
.cell.mine-revealed {
  background: var(--bg-tertiary);
  border-color: #EF444466;
}

.cell.mine-revealed::after {
  content: '💣';
  font-size: clamp(10px, 2.5vw, 14px);
  opacity: 0.7;
}

/* Wrong flag (flagged but not a mine) */
.cell.wrong-flag {
  background: #7F1D1D;
  border-color: #EF4444;
}

.cell.wrong-flag::after {
  content: '❌';
  font-size: clamp(10px, 2.5vw, 14px);
}

/* Correct flag (game over, was correct) */
.cell.correct-flag {
  background: var(--bg-tertiary);
  border-color: #22C55E66;
}

.cell.correct-flag::after {
  content: '🚩';
  font-size: clamp(10px, 2.5vw, 15px);
}

/* Win highlight */
.cell.win-reveal {
  animation: winPop 0.4s ease forwards;
}

@keyframes winPop {
  0%   { transform: scale(1); }
  50%  { transform: scale(1.1); }
  100% { transform: scale(1); background: rgba(59,130,246,0.15); border-color: var(--accent); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%       { transform: translateX(-4px); }
  40%       { transform: translateX(4px); }
  60%       { transform: translateX(-3px); }
  80%       { transform: translateX(3px); }
}

/* Number colors */
.num-1 { color: var(--num-1); }
.num-2 { color: var(--num-2); }
.num-3 { color: var(--num-3); }
.num-4 { color: var(--num-4); }
.num-5 { color: var(--num-5); }
.num-6 { color: var(--num-6); }
.num-7 { color: var(--num-7); }
.num-8 { color: var(--num-8); }

/* ============================================================
   FOOTER
   ============================================================ */
.game-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
  gap: 12px;
  flex-shrink: 0;
}

.mode-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 600;
  transition: background 0.15s, border-color 0.15s, box-shadow 0.15s;
  font-family: inherit;
  flex: 1;
}

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

.mode-toggle:active {
  transform: scale(0.97);
}

.mode-toggle.flag-mode {
  border-color: #F59E0B;
  box-shadow: 0 0 8px rgba(245, 158, 11, 0.25);
}

.mode-icon {
  font-size: 18px;
  line-height: 1;
}

.mode-label {
  color: var(--text-secondary);
  font-size: 13px;
}

.btn-icon {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  color: var(--text-primary);
  font-size: 18px;
  font-weight: 600;
  transition: background 0.15s, transform 0.1s;
  font-family: inherit;
}

.btn-icon .btn-text {
  font-size: 13px;
  color: var(--text-secondary);
}

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

.btn-icon:active {
  transform: scale(0.95);
}

/* ============================================================
   SCROLLBAR HIDE
   ============================================================ */
::-webkit-scrollbar { display: none; }