/* Reset and Root Variables */
*, *::after, *::before {
  box-sizing: border-box;
}

:root {
  --cell-size: 120px;
  --mark-size: calc(var(--cell-size) * 0.7);
  
  /* Knight Logics Color Scheme */
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --accent-color: #e74c3c;
  --success-color: #27ae60;
  --warning-color: #f39c12;
  --dark-color: #1a252f;
  --light-color: #ecf0f1;
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.2);
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-size-large: 2rem;
  --font-size-medium: 1.2rem;
  --font-size-small: 0.9rem;
  
  /* Shadows */
  --shadow-light: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-medium: 0 8px 25px rgba(0, 0, 0, 0.15);
  --shadow-heavy: 0 15px 35px rgba(0, 0, 0, 0.2);
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-medium: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Body and Layout */
body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  color: var(--light-color);
  overflow-x: hidden;
  overflow-y: auto;
}

.has-site-header { padding-top: 120px; }
@media (max-width: 768px) { .has-site-header { padding-top: 90px; } }

.game-container { padding-bottom: 140px; position: relative; z-index: 1; }

#siteFooter { position: relative; z-index: 20; margin-top: 40px; }
#siteFooter .footer {
  color: #e5e7eb;
  background: #0a0a0a;
  border-top: 1px solid rgba(255,255,255,0.1);
  opacity: 1;
  transform: none;
  transition: none;
}
#siteFooter .footer a { color: #64ffda; }
#siteFooter .footer a:hover { color: #ffffff; }

.demo-banner {
  background: rgba(99, 102, 241, 0.15);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  color: #e5e7eb;
  font-size: 0.9rem;
  padding: 0.5rem 2rem;
}
.demo-banner .banner-content { max-width: 1200px; margin: 0 auto; display: flex; gap: 1rem; align-items: center; }
.demo-banner .banner-tag { color: #e5e7eb; font-weight: 600; display: inline-flex; align-items: center; gap: 0.4rem; }
.demo-banner .banner-tag i { color: var(--warning-color); }
.demo-banner .banner-close { margin-left: auto; background: transparent; color: #e5e7eb; border: 1px solid rgba(255,255,255,0.2); border-radius: 6px; padding: 2px 10px; cursor: pointer; transition: all 150ms ease; }
.demo-banner .banner-close:hover { color: #ffffff; border-color: #64ffda; }

.game-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 1;
}

/* Header Styles */
.game-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 2rem;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--shadow-light);
}

.logo-section {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.game-logo {
  width: 50px;
  height: 50px;
  object-fit: contain;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.game-header h1 {
  margin: 0;
  font-size: var(--font-size-large);
  font-weight: 600;
  background: linear-gradient(45deg, var(--secondary-color), var(--light-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.game-stats {
  display: flex;
  align-items: center;
}

.score-display {
  display: flex;
  gap: 2rem;
  background: var(--glass-bg);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  border: 1px solid var(--glass-border);
}

.player-score {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}

.score-label {
  font-size: var(--font-size-small);
  opacity: 0.8;
  font-weight: 500;
}

.score-value {
  font-size: var(--font-size-medium);
  font-weight: 700;
  color: var(--secondary-color);
}

/* Main Game Area */
.main-game-area {
  flex: 1;
  display: flex;
  padding: 2rem;
  gap: 2rem;
  align-items: flex-start;
}

.game-column {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
}

/* Game Info Panel */
.game-info-panel {
  background: var(--glass-bg);
  backdrop-filter: blur(15px);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 1.5rem;
  box-shadow: var(--shadow-medium);
  width: 100%;
  max-width: 400px;
}

.current-player {
  text-align: center;
  margin-bottom: 1rem;
}

.current-player h2 {
  margin: 0 0 0.5rem 0;
  font-size: var(--font-size-medium);
  font-weight: 600;
}

.turn-indicator {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 1rem;
}

.turn-symbol {
  font-size: 2rem;
  padding: 0.5rem;
  background: var(--glass-bg);
  border: 2px solid var(--secondary-color);
  border-radius: 50%;
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-medium);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.game-controls {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  flex-wrap: wrap;
}

.game-btn {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 0.5rem 1rem;
  color: var(--light-color);
  font-family: var(--font-family);
  font-size: var(--font-size-small);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.game-btn:hover {
  background: var(--secondary-color);
  border-color: var(--secondary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-medium);
}

.game-btn.primary {
  background: var(--secondary-color);
  border-color: var(--secondary-color);
}

.game-btn.secondary {
  background: transparent;
  border-color: var(--light-color);
}

/* Board Container */
.board-container {
  background: var(--glass-bg);
  backdrop-filter: blur(15px);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--shadow-heavy);
}

.board {
  display: grid;
  grid-template-columns: repeat(3, var(--cell-size));
  grid-template-rows: repeat(3, var(--cell-size));
  gap: 8px;
  background: var(--dark-color);
  padding: 8px;
  border-radius: 16px;
  box-shadow: inset 0 4px 8px rgba(0, 0, 0, 0.3);
}

.cell {
  width: var(--cell-size);
  height: var(--cell-size);
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 2px solid var(--glass-border);
  border-radius: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  cursor: pointer;
  transition: var(--transition-fast);
  font-size: 3rem;
  font-weight: bold;
}

.cell:hover:not(.x):not(.circle) {
  background: rgba(255, 255, 255, 0.2);
  border-color: var(--secondary-color);
  transform: scale(1.05);
  box-shadow: var(--shadow-medium);
}

.cell.x,
.cell.circle {
  cursor: not-allowed;
  animation: cellPlace 0.3s ease;
}

@keyframes cellPlace {
  0% { transform: scale(0); }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); }
}

.cell.x {
  color: var(--accent-color);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.cell.circle {
  color: var(--secondary-color);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.cell.x::after {
  content: '✕';
}

.cell.circle::after {
  content: '○';
}

/* Hover Effects for Preview */
.board.x .cell:not(.x):not(.circle):hover::after {
  content: '✕';
  color: var(--accent-color);
  opacity: 0.5;
}

.board.circle .cell:not(.x):not(.circle):hover::after {
  content: '○';
  color: var(--secondary-color);
  opacity: 0.5;
}

/* Game Sidebar */
.game-sidebar {
  width: 320px;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.game-mode-panel,
.match-history,
.game-tips {
  background: var(--glass-bg);
  backdrop-filter: blur(15px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: var(--shadow-medium);
}

.game-mode-panel h3,
.match-history h3,
.game-tips h3 {
  margin: 0 0 1rem 0;
  font-size: var(--font-size-medium);
  font-weight: 600;
  color: var(--light-color);
}

.mode-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.mode-option {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 8px;
  transition: var(--transition-fast);
}

.mode-option:hover {
  background: rgba(255, 255, 255, 0.1);
}

.mode-option input[type="radio"] {
  accent-color: var(--secondary-color);
}

.mode-label {
  font-weight: 500;
}

.history-list {
  max-height: 200px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.history-item {
  background: rgba(255, 255, 255, 0.1);
  padding: 0.75rem;
  border-radius: 8px;
  border-left: 3px solid var(--secondary-color);
  font-size: var(--font-size-small);
}

.history-placeholder {
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
  font-style: italic;
  padding: 1rem;
}

.tip-container {
  background: rgba(255, 255, 255, 0.1);
  padding: 1rem;
  border-radius: 12px;
  border-left: 4px solid var(--warning-color);
}

.tip {
  margin: 0;
  font-size: var(--font-size-small);
  line-height: 1.5;
}

/* Winning Message Modal */
.winning-message {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  justify-content: center;
  align-items: center;
  z-index: 1000;
  animation: fadeIn 0.3s ease;
}

.winning-message.show {
  display: flex;
}

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

.winning-content {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 3rem;
  text-align: center;
  box-shadow: var(--shadow-heavy);
  animation: slideIn 0.5s ease;
  max-width: 400px;
  width: 90%;
}

@keyframes slideIn {
  from {
    transform: translateY(-50px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.winner-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  animation: bounce 1s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
  40% { transform: translateY(-10px); }
  60% { transform: translateY(-5px); }
}

.winning-text {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2rem;
  background: linear-gradient(45deg, var(--secondary-color), var(--light-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.game-result-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

/* Background Effects */
.background-effects {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
}

.floating-symbol {
  position: absolute;
  font-size: 2rem;
  color: rgba(255, 255, 255, 0.1);
  animation: float 20s infinite linear;
}

.floating-symbol:nth-child(1) {
  left: 10%;
  animation-delay: 0s;
}

.floating-symbol:nth-child(2) {
  left: 30%;
  animation-delay: -5s;
}

.floating-symbol:nth-child(3) {
  left: 60%;
  animation-delay: -10s;
}

.floating-symbol:nth-child(4) {
  left: 80%;
  animation-delay: -15s;
}

@keyframes float {
  from {
    transform: translateY(100vh) rotate(0deg);
  }
  to {
    transform: translateY(-100px) rotate(360deg);
  }
}

/* Responsive Design */
@media (max-width: 1024px) {
  .main-game-area {
    flex-direction: column;
    align-items: center;
  }
  
  .game-sidebar {
    width: 100%;
    max-width: 400px;
  }
}

@media (max-width: 768px) {
  :root {
    --cell-size: 100px;
  }
  
  .game-header {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
  }
  
  .score-display {
    gap: 1rem;
  }
  
  .main-game-area {
    padding: 1rem;
    gap: 1rem;
  }
  
  .board-container {
    padding: 1rem;
  }
  
  .game-header h1 {
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  :root {
    --cell-size: 80px;
  }
  
  .game-header h1 {
    font-size: 1.2rem;
  }
  
  .winning-content {
    padding: 2rem 1rem;
  }
  
  .winning-text {
    font-size: 1.5rem;
  }
  
  .game-result-actions {
    flex-direction: column;
  }
}