/**
 * Complete CSS Example - Chess Board Styling
 * Use this as a reference for styling the chess game
 */

/* ==================== GLOBAL STYLES ==================== */

:root {
  /* Board dimensions */
  --board-size: 600px;
  --square-size: calc(var(--board-size) / 8);

  /* Colors */
  --light-square: #f0d9b5;
  --dark-square: #b58863;
  --highlight-selected: rgba(255, 255, 0, 0.4);
  --highlight-valid-move: rgba(0, 255, 0, 0.3);
  --highlight-check: rgba(255, 0, 0, 0.5);
  --highlight-last-move: rgba(255, 255, 0, 0.2);

  /* Piece colors */
  --piece-white: #ffffff;
  --piece-black: #000000;

  /* UI colors */
  --bg-primary: #2c3e50;
  --bg-secondary: #34495e;
  --text-primary: #ecf0f1;
  --text-secondary: #bdc3c7;
  --accent: #3498db;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;

  /* Animations */
  --transition-fast: 0.15s;
  --transition-medium: 0.3s;
  --transition-slow: 0.5s;
}

/* ==================== LAYOUT ==================== */

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: var(--spacing-lg);
}

.game-container {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: var(--spacing-xl);
  max-width: 1400px;
}

/* ==================== CHESS BOARD ==================== */

.board-container {
  position: relative;
}

.board {
  display: grid;
  grid-template-columns: repeat(8, var(--square-size));
  grid-template-rows: repeat(8, var(--square-size));
  border: 2px solid var(--text-secondary);
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

/* ==================== SQUARES ==================== */

.square {
  width: var(--square-size);
  height: var(--square-size);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: background-color var(--transition-fast);
  cursor: pointer;
}

/* Alternating colors */
.square--light {
  background-color: var(--light-square);
}

.square--dark {
  background-color: var(--dark-square);
}

/* Square states */
.square--selected {
  background-color: var(--highlight-selected) !important;
  box-shadow: inset 0 0 0 3px rgba(255, 255, 0, 0.8);
}

.square--valid-move {
  cursor: pointer;
}

.square--valid-move::after {
  content: '';
  position: absolute;
  width: 30%;
  height: 30%;
  background-color: var(--highlight-valid-move);
  border-radius: 50%;
  pointer-events: none;
}

/* Valid move on occupied square (capture) */
.square--valid-move.square--occupied::after {
  width: 90%;
  height: 90%;
  background-color: transparent;
  border: 3px solid rgba(255, 0, 0, 0.5);
  border-radius: 50%;
}

.square--check {
  background-color: var(--highlight-check) !important;
  animation: pulse-check 1s infinite;
}

.square--last-move {
  background-color: var(--highlight-last-move);
}

/* Hover effects */
.square:hover {
  filter: brightness(1.1);
}

/* ==================== COORDINATES ==================== */

.coordinates {
  position: absolute;
  font-size: 12px;
  font-weight: bold;
  color: var(--text-secondary);
  user-select: none;
}

.coordinate--file {
  bottom: 2px;
  right: 4px;
}

.coordinate--rank {
  top: 2px;
  left: 4px;
}

/* ==================== PIECES ==================== */

.piece {
  font-size: calc(var(--square-size) * 0.7);
  cursor: grab;
  user-select: none;
  transition: transform var(--transition-fast);
  pointer-events: auto;
}

.piece:hover {
  transform: scale(1.1);
}

.piece:active {
  cursor: grabbing;
}

.piece--dragging {
  opacity: 0.5;
  cursor: grabbing;
}

/* Piece colors using filters (if using images) */
.piece--white {
  filter: brightness(1.2);
}

.piece--black {
  filter: brightness(0.3);
}

/* ==================== GAME INFO ==================== */

.game-info {
  background: var(--bg-secondary);
  padding: var(--spacing-lg);
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.game-info h1 {
  font-size: 28px;
  margin-bottom: var(--spacing-md);
  color: var(--accent);
}

.turn-indicator {
  padding: var(--spacing-md);
  background: var(--bg-primary);
  border-radius: 4px;
  text-align: center;
  margin-bottom: var(--spacing-md);
  font-weight: bold;
  font-size: 18px;
}

.turn-indicator--white {
  color: #fff;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.turn-indicator--black {
  color: #fff;
  background: linear-gradient(135deg, #434343 0%, #000000 100%);
}

.status-message {
  padding: var(--spacing-sm);
  border-radius: 4px;
  text-align: center;
  margin-top: var(--spacing-md);
}

.status-message--info {
  background: rgba(52, 152, 219, 0.2);
  border: 1px solid var(--accent);
}

.status-message--warning {
  background: rgba(230, 126, 34, 0.2);
  border: 1px solid #e67e22;
  color: #e67e22;
}

.status-message--error {
  background: rgba(231, 76, 60, 0.2);
  border: 1px solid #e74c3c;
  color: #e74c3c;
}

.status-message--success {
  background: rgba(46, 204, 113, 0.2);
  border: 1px solid #2ecc71;
  color: #2ecc71;
}

/* ==================== CONTROLS ==================== */

.game-controls {
  background: var(--bg-secondary);
  padding: var(--spacing-lg);
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

button {
  padding: var(--spacing-md);
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  transition: all var(--transition-fast);
}

button:hover {
  background: #2980b9;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

button:active {
  transform: translateY(0);
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ==================== CAPTURED PIECES ==================== */

.captured-pieces {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.captured-section {
  background: var(--bg-primary);
  padding: var(--spacing-md);
  border-radius: 4px;
}

.captured-section h3 {
  font-size: 14px;
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

.captured-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.captured-piece {
  font-size: 24px;
  opacity: 0.6;
}

/* ==================== ANIMATIONS ==================== */

@keyframes pulse-check {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.6;
  }
}

@keyframes piece-move {
  from {
    transform: scale(1);
  }
  50% {
    transform: scale(1.2);
  }
  to {
    transform: scale(1);
  }
}

@keyframes piece-capture {
  from {
    transform: scale(1) rotate(0deg);
    opacity: 1;
  }
  to {
    transform: scale(0) rotate(180deg);
    opacity: 0;
  }
}

.piece--moving {
  animation: piece-move var(--transition-medium) ease;
}

.piece--captured {
  animation: piece-capture var(--transition-medium) ease forwards;
}

/* ==================== RESPONSIVE DESIGN ==================== */

@media (max-width: 1200px) {
  .game-container {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
  }

  :root {
    --board-size: 480px;
  }
}

@media (max-width: 600px) {
  :root {
    --board-size: 320px;
  }

  body {
    padding: var(--spacing-sm);
  }

  .piece {
    font-size: calc(var(--square-size) * 0.6);
  }
}

/* ==================== MODAL (for pawn promotion) ==================== */

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal {
  background: var(--bg-secondary);
  padding: var(--spacing-xl);
  border-radius: 8px;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.4);
}

.modal h2 {
  margin-bottom: var(--spacing-lg);
  text-align: center;
}

.promotion-choices {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-md);
}

.promotion-choice {
  padding: var(--spacing-lg);
  font-size: 48px;
  background: var(--bg-primary);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.promotion-choice:hover {
  background: var(--accent);
  border-color: white;
  transform: scale(1.1);
}

/* ==================== DRAG AND DROP ==================== */

.square--drag-over {
  background-color: var(--highlight-valid-move) !important;
}

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