/* ============================================
   구구단 스피드 퀴즈 - Minimalist Design
   ============================================ */

/* --- CSS Variables --- */
:root {
  /* Light, airy palette */
  --bg-primary: #fff8f0;
  --bg-secondary: #fce8d5;
  --bg-card: #ffffff;
  --bg-card-hover: #fff3e8;

  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-muted: #94a3b8;

  --accent-primary: #f97316;
  --accent-primary-light: #fb923c;
  --accent-secondary: #10b981;
  --accent-danger: #ef4444;
  --accent-warning: #f59e0b;
  --accent-info: #3b82f6;

  --border-color: #e0e0e0;
  --border-light: #eeeeee;

  /* Shadows - very subtle */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.08);

  /* Typography */
  --font-display: 'Outfit', sans-serif;
  --font-body: 'Noto Sans KR', sans-serif;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 120ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 350ms ease;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

/* body는 .game-shell-body (공유 CSS)에서 100dvh flex column 처리 */
body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#app {
  flex: 1 1 0;
  min-height: 0;
  width: 100%;
  max-width: 460px;
  margin: 0 auto;
  position: relative;
  padding: 3.5rem var(--space-lg) var(--space-lg);
  padding-bottom: calc(var(--space-lg) + env(safe-area-inset-bottom, 0px));
  overflow-y: auto;
  scrollbar-width: thin;
}

/* --- Typography --- */
h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 {
  font-size: 1.75rem;
}

h2 {
  font-size: 1.375rem;
}

h3 {
  font-size: 1.125rem;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 14px var(--space-xl);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  background: var(--bg-card);
  color: var(--text-primary);
}

.btn:active {
  transform: scale(0.98);
}

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

.btn-primary:hover {
  background: #ea6c0a;
  border-color: #ea6c0a;
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

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

.btn-success {
  background: var(--accent-secondary);
  color: #ffffff;
  border-color: var(--accent-secondary);
}

.btn-danger {
  background: var(--accent-danger);
  color: #ffffff;
  border-color: var(--accent-danger);
}

.btn-danger:hover {
  background: #c23535;
}

.btn-lg {
  padding: 16px var(--space-2xl);
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.btn-full {
  width: 100%;
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

/* --- Cards --- */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--border-light);
}

.card-glass {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
}

/* --- Toggle Buttons (단 선택) --- */
.toggle-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background: var(--bg-primary);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-normal);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

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

.toggle-btn:not(.active):hover {
  border-color: var(--accent-primary-light);
  color: var(--text-primary);
}

/* --- Timer Bar --- */
.timer-bar-container {
  width: 100%;
  height: 4px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-md);
}

.timer-bar {
  height: 100%;
  background: var(--accent-primary);
  border-radius: var(--radius-full);
  transition: width 100ms linear;
}

.timer-bar.warning {
  background: var(--accent-danger);
}

/* --- Quiz Specific --- */
.question-display {
  font-family: var(--font-display);
  font-size: 3.2rem;
  font-weight: 900;
  text-align: center;
  padding: var(--space-2xl) 0;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

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

.choice-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg) var(--space-md);
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 800;
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  min-height: 100px;
}

.choice-btn:hover {
  border-color: var(--accent-primary);
  background: var(--bg-primary);
}

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

.choice-btn.correct {
  background: var(--accent-secondary);
  border-color: var(--accent-secondary);
  color: #ffffff;
  animation: pop 0.3s ease;
}

.choice-btn.wrong {
  background: var(--accent-danger);
  border-color: var(--accent-danger);
  color: #ffffff;
  animation: shake 0.35s ease;
}

.choice-btn.reveal-correct {
  border-color: var(--accent-secondary);
  color: var(--accent-secondary);
  border-width: 2px;
}

.choice-btn.disabled {
  pointer-events: none;
  opacity: 0.65;
}

/* --- Score Counter --- */
.score-counter {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) 0;
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.score-counter .correct-count {
  color: var(--accent-secondary);
  font-size: 1.05rem;
}

.score-counter .timer-text {
  color: var(--text-primary);
  font-size: 1.2rem;
  font-weight: 800;
}

.score-counter .timer-text.warning {
  color: var(--accent-danger);
  animation: pulse-warning 0.5s ease infinite;
}

/* --- Result Screen --- */
.result-score {
  font-family: var(--font-display);
  font-size: 4.5rem;
  font-weight: 900;
  text-align: center;
  color: var(--text-primary);
  letter-spacing: -0.03em;
}

.result-stats {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-sm);
  text-align: center;
}

.result-stat-item {
  padding: var(--space-md);
}

.result-stat-value {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
}

.result-stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
  letter-spacing: 0.02em;
}

.wrong-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.wrong-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px var(--space-md);
  background: #fef2f2;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--accent-danger);
}

.wrong-item .problem {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--text-primary);
}

.wrong-item .your-answer {
  color: var(--accent-danger);
  font-weight: 600;
  text-decoration: line-through;
}

.wrong-item .correct-answer {
  color: var(--accent-secondary);
  font-weight: 700;
}

/* --- Statistics --- */
.tabs {
  display: flex;
  gap: 0;
  background: var(--bg-secondary);
  padding: 3px;
  border-radius: var(--radius-md);
  margin-bottom: var(--space-lg);
}

.tab {
  flex: 1;
  padding: 10px var(--space-md);
  border: none;
  border-radius: 8px;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-normal);
  -webkit-tap-highlight-color: transparent;
}

.tab.active {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

.heatmap-grid {
  display: grid;
  grid-template-columns: auto repeat(9, 1fr);
  gap: 3px;
  font-family: var(--font-display);
  font-size: 0.7rem;
}

.heatmap-header {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4px;
  color: var(--text-muted);
  font-weight: 600;
}

.heatmap-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1;
  border-radius: 4px;
  font-weight: 700;
  font-size: 0.6rem;
  transition: transform var(--transition-fast);
}

.heatmap-cell:hover {
  transform: scale(1.15);
  z-index: 1;
}

.heatmap-label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--text-secondary);
}

/* Heatmap color scale - muted tones */
.heat-0 {
  background: var(--bg-secondary);
  color: var(--text-muted);
}

.heat-1 {
  background: #f8d7da;
  color: #842029;
}

.heat-2 {
  background: #fde2c8;
  color: #7c4a1e;
}

.heat-3 {
  background: #fef3cd;
  color: #664d03;
}

.heat-4 {
  background: #d1ecf1;
  color: #0c5460;
}

.heat-5 {
  background: #d4edda;
  color: #155724;
}

.chart-container {
  width: 100%;
  height: 180px;
  margin: var(--space-md) 0;
}

.stat-summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: var(--space-lg);
}

.stat-summary-card {
  text-align: center;
  padding: var(--space-lg);
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
}

.stat-summary-card .value {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-primary);
}

.stat-summary-card .label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
  letter-spacing: 0.02em;
}

.top-wrong-list {
  list-style: none;
}

.top-wrong-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: 10px 0;
  border-bottom: 1px solid var(--border-light);
}

.top-wrong-item:last-child {
  border-bottom: none;
}

.top-wrong-rank {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.95rem;
  color: var(--accent-danger);
  min-width: 24px;
}

.top-wrong-problem {
  font-family: var(--font-display);
  font-weight: 700;
  flex: 1;
}

.top-wrong-rate {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* --- Countdown Overlay --- */
.countdown-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 248, 240, 0.95);
  z-index: 100;
}

.countdown-number {
  font-family: var(--font-display);
  font-size: 7rem;
  font-weight: 900;
  color: var(--text-primary);
  animation: countdown-pop 0.6s ease;
}

/* --- Section Headers --- */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.section-title {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.section-badge {
  font-size: 0.7rem;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  font-weight: 600;
  border: 1px solid var(--border-light);
}

/* --- Empty State --- */
.empty-state {
  text-align: center;
  padding: var(--space-3xl) var(--space-lg);
  color: var(--text-muted);
}

.empty-state .icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-md);
}

/* --- Spacing Utilities --- */
.mt-sm {
  margin-top: var(--space-sm);
}

.mt-md {
  margin-top: var(--space-md);
}

.mt-lg {
  margin-top: var(--space-lg);
}

.mt-xl {
  margin-top: var(--space-xl);
}

.mt-2xl {
  margin-top: var(--space-2xl);
}

.mb-sm {
  margin-bottom: var(--space-sm);
}

.mb-md {
  margin-bottom: var(--space-md);
}

.mb-lg {
  margin-bottom: var(--space-lg);
}

.mb-xl {
  margin-bottom: var(--space-xl);
}

.gap-md {
  gap: var(--space-md);
}

.gap-lg {
  gap: var(--space-lg);
}

.flex-col {
  display: flex;
  flex-direction: column;
}

.text-center {
  text-align: center;
}

.text-muted {
  color: var(--text-muted);
}

.text-sm {
  font-size: 0.875rem;
}

/* --- Navigation --- */
.nav-back {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-muted);
  font-weight: 600;
  cursor: pointer;
  background: none;
  border: none;
  font-family: var(--font-body);
  font-size: 0.85rem;
  padding: var(--space-sm) 0;
  margin-bottom: var(--space-lg);
  transition: color var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.nav-back:hover {
  color: var(--text-primary);
}

/* --- Confetti Container --- */
.confetti-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 200;
  overflow: hidden;
}

.confetti-piece {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  animation: confetti-fall 1.5s ease-out forwards;
}

/* --- Animations (subtle) --- */
@keyframes pop {

  0%,
  100% {
    transform: scale(1);
  }

  50% {
    transform: scale(1.04);
  }
}

@keyframes shake {

  0%,
  100% {
    transform: translateX(0);
  }

  20% {
    transform: translateX(-6px);
  }

  40% {
    transform: translateX(6px);
  }

  60% {
    transform: translateX(-3px);
  }

  80% {
    transform: translateX(3px);
  }
}

@keyframes pulse-warning {
  0% {
    transform: scale(1);
  }

  50% {
    transform: scale(1.05);
  }

  100% {
    transform: scale(1);
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes animate-slide-up {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes countdown-pop {
  0% {
    opacity: 0;
    transform: scale(0.5);
  }

  50% {
    opacity: 1;
    transform: scale(1.2);
  }

  100% {
    opacity: 1;
    transform: scale(1);
  }
}

.animate-slide-up {
  animation: animate-slide-up 0.5s ease-out both;
}

/* --- Modal --- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xl);
  animation: fade-in 0.2s ease-out;
}

.modal-content {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  width: 100%;
  max-width: 320px;
  box-shadow: var(--shadow-md);
  text-align: center;
}

.modal-content h3 {
  margin-bottom: var(--space-sm);
}

.modal-content p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: var(--space-lg);
  line-height: 1.5;
}

.modal-actions {
  display: flex;
  gap: var(--space-sm);
}

.modal-actions .btn {
  flex: 1;
  padding: 10px;
  font-size: 0.9rem;
}

@keyframes countdown-pop {
  0% {
    transform: scale(0.5);
    opacity: 0;
  }

  60% {
    transform: scale(1.08);
    opacity: 1;
  }

  100% {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slide-up {
  from {
    opacity: 0;
    transform: translateY(16px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes confetti-fall {
  0% {
    transform: translateY(-10px) rotate(0deg);
    opacity: 1;
  }

  100% {
    transform: translateY(100vh) rotate(720deg);
    opacity: 0;
  }
}

.animate-fade-in {
  animation: fade-in 0.25s ease forwards;
}

.animate-slide-up {
  animation: slide-up 0.3s ease forwards;
}

/* --- Page transitions --- */
.page-enter {
  animation: fade-in 0.2s ease forwards;
}

/* --- Radio Buttons (시간 선택) --- */
.radio-group {
  display: flex;
  gap: 8px;
}

.radio-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background: var(--bg-primary);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-normal);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

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

/* --- Logo --- */
.logo-container {
  text-align: center;
  padding: var(--space-2xl) 0 var(--space-xl);
}

.logo-emoji {
  font-size: 2.5rem;
  display: block;
  margin-bottom: var(--space-md);
}

.logo-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 900;
  color: var(--text-primary);
  letter-spacing: -0.03em;
}

.logo-subtitle {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: var(--space-xs);
}

/* --- Focus Mode Badge --- */
.weakness-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 3px 10px;
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: var(--radius-full);
  color: var(--accent-danger);
  font-size: 0.75rem;
  font-weight: 600;
}

/* --- No Data Message --- */
.no-data-message {
  text-align: center;
  padding: var(--space-3xl) var(--space-lg);
  color: var(--text-muted);
}

.no-data-message .emoji {
  font-size: 2.5rem;
  display: block;
  margin-bottom: var(--space-md);
}

/* --- Responsive --- */
@media (max-width: 360px) {
  :root {
    font-size: 14px;
  }

  .question-display {
    font-size: 2.6rem;
  }

  .choice-btn {
    font-size: 1.4rem;
    min-height: 64px;
  }
}

@media (min-width: 481px) {
  #app {
    padding: var(--space-2xl) var(--space-xl);
  }
}