:root {
  --bg: #0f172a;
  /* Slight Dark Slate */
  --panel: #1e293b;
  /* Medium Slate */
  --primary: #94a3b8;
  /* Muted Slate Text */
  --accent-teal: #2dd4bf;
  --accent-purple: #a855f7;
  --accent-orange: #fb923c;
  --accent-mint: #4ade80;
  --text: #f8fafc;
  /* Off-white */
  --text-muted: #64748b;
  --card-face: #334155;
  /* Slightly lighter than panel */
  --card-back: #ffffff;
  /* White back for emojis */
  --card-border: #475569;
  /* Visible border */
  --success: #10b981;
  --danger: #f43f5e;
  --match-bg: #1e293b;
  --radius: 12px;
  --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

body.light-theme {
  --bg: #f8fafc;
  --panel: #ffffff;
  --primary: #000000;
  --accent-teal: #0d9488;
  --accent-purple: #7e22ce;
  --text: #000000;
  --text-muted: #333333;
  --card-face: #e2e8f0;
  --card-back: #ffffff;
  --card-border: #cbd5e1;
  --match-bg: #f1f5f9;
  --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
  font-family: 'Outfit', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

/* --- Theme Toggle --- */
.theme-toggle {
  position: absolute;
  top: 20px;
  right: 20px;
  background: var(--panel);
  border: 1px solid var(--card-border);
  color: var(--text);
  width: 44px;
  height: 44px;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all 0.2s;
  z-index: 100;
  box-shadow: var(--shadow);
}

.theme-toggle:hover {
  border-color: var(--accent-teal);
  color: var(--accent-teal);
  transform: scale(1.05);
}

body.light-theme .fa-moon {
  display: none;
}

body:not(.light-theme) .fa-sun {
  display: none;
}

.no-select {
  user-select: none;
  -webkit-user-select: none;
}

#game-container {
  width: 100%;
  max-width: 650px;
  padding: 20px;
}

.screen {
  width: 100%;
  animation: fadeIn 0.4s ease-out;
}

.hidden {
  display: none !important;
}

/* Panel Styling */
.card-panel {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 2.5rem;
  box-shadow: var(--shadow);
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  font-weight: 800;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--accent-teal), var(--accent-purple));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

p {
  color: var(--text-muted);
  margin-bottom: 2rem;
}

/* Setup Groups */
.setup-group {
  margin-bottom: 1.5rem;
  text-align: left;
}

.setup-group label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 0.75rem;
  letter-spacing: 1px;
}

.selector {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

#theme-selector .selector {
  grid-template-columns: repeat(3, 1fr);
}

@media (max-width: 500px) {
  #theme-selector .selector {
    grid-template-columns: repeat(2, 1fr);
  }
}

.choice {
  background: rgba(15, 23, 42, 0.5);
  border: 2px solid var(--card-border);
  padding: 12px 8px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-weight: 600;
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.9rem;
}

.choice span {
  display: block;
  font-size: 0.7rem;
  font-weight: 400;
  opacity: 0.6;
}

.choice:hover {
  border-color: var(--primary);
}

.choice.active {
  background: var(--accent-teal);
  border-color: var(--accent-teal);
  color: var(--bg);
  box-shadow: 0 0 15px rgba(45, 212, 191, 0.3);
}

.options-drawer {
  margin-top: 10px;
  padding: 12px;
  background: rgba(15, 23, 42, 0.5);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  border: 1px solid var(--card-border);
}

select {
  background: var(--panel);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid var(--card-border);
  outline: none;
  cursor: pointer;
}

/* Buttons */
.btn {
  padding: 16px 24px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-weight: 700;
  font-size: 1rem;
  transition: all 0.2s ease;
}

.btn.primary {
  background: linear-gradient(135deg, var(--accent-teal), var(--accent-purple));
  color: white;
  width: 100%;
  margin-top: 1rem;
}

.btn.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

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

.btn-icon {
  background: var(--panel);
  border: 1px solid var(--card-border);
  width: 44px;
  height: 44px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  transition: all 0.2s;
}

.btn-icon:hover {
  border-color: var(--accent-teal);
  color: var(--accent-teal);
}

/* Game Interface */
.game-header {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  align-items: center;
}

.status-panel {
  flex-grow: 1;
  background: var(--panel);
  border-radius: var(--radius);
  padding: 8px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

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

.stat-label {
  font-size: 0.6rem;
  text-transform: uppercase;
  color: var(--primary);
  font-weight: 800;
}

.stat-value {
  font-weight: 800;
  font-size: 1.1rem;
}

/* Grid System */
#game-board {
  display: grid;
  gap: 10px;
  margin: 0 auto;
}

#game-board.easy {
  grid-template-columns: repeat(4, 1fr);
}

#game-board.medium {
  grid-template-columns: repeat(5, 1fr);
}

#game-board.hard {
  grid-template-columns: repeat(6, 1fr);
}

/* Card - Instant Reveal (No Flip) */
.memory-card {
  aspect-ratio: 1/1;
  position: relative;
  cursor: pointer;
  background: var(--card-face);
  border-radius: var(--radius);
  border: 2px solid var(--card-border);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.memory-card:active {
  transform: scale(0.95);
}

.memory-card.revealed {
  background: var(--card-back);
  border-color: var(--accent-teal);
  cursor: default;
}

.memory-card.matched {
  background: var(--match-bg);
  border-color: var(--success);
  cursor: default;
  opacity: 0.6;
}

/* Emoji visibility logic */
.memory-card .emoji {
  display: none;
  font-size: 2.5rem;
  color: #1e293b;
}

.memory-card.revealed .emoji,
.memory-card.matched .emoji {
  display: block;
}

/* Blank state indicator */
.memory-card:not(.revealed):not(.matched)::after {
  content: '?';
  font-size: 1.5rem;
  color: var(--accent-teal);
  opacity: 0.2;
}

/* Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(5px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

body.light-theme .modal-overlay {
  background: rgba(255, 255, 255, 0.85);
}

.modal {
  max-width: 400px;
  width: 90%;
  animation: modalIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal-actions {
  display: flex;
  gap: 12px;
  margin-top: 2rem;
}

.modal-actions .btn {
  flex: 1;
  margin: 0;
  width: auto;
  font-size: 0.9rem;
  padding: 14px 10px;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

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

@keyframes modalIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }

  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* Mobile Adjustments */
@media (max-width: 600px) {
  #game-container {
    padding: 10px;
  }

  .card-panel {
    padding: 1.5rem;
  }

  h1 {
    font-size: 1.8rem;
  }

  .card-face {
    font-size: 1.8rem;
  }

  #game-board {
    gap: 8px;
  }

  .status-panel {
    padding: 8px 12px;
  }

  .stat-value {
    font-size: 0.95rem;
  }
}