/* Chess Trainer Styles */

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

:root {
  --bg: #f0f4f8;
  --card-bg: #ffffff;
  --text: #2d3748;
  --text-light: #718096;
  --accent: #4c6ef5;
  --accent-hover: #3b5bdb;
  --green: #38a169;
  --green-hover: #2f855a;
  --red: #e53e3e;
  --orange: #dd6b20;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --radius: 12px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* Header */
.chess-header {
  text-align: center;
  padding: 1.25rem 1rem 0.75rem;
}

.chess-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
}

.back-link {
  display: inline-block;
  margin-top: 0.3rem;
  font-size: 0.85rem;
  color: var(--accent);
  text-decoration: none;
}

.back-link:hover {
  text-decoration: underline;
}

/* Setup Screen */
.setup-screen {
  max-width: 480px;
  margin: 1rem auto;
  padding: 0 1rem;
}

.setup-section {
  margin-bottom: 1.5rem;
}

.setup-section h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  text-align: center;
}

.color-choices {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

.color-card {
  flex: 1;
  max-width: 180px;
  background: var(--card-bg);
  border: 3px solid transparent;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.15s;
}

.color-card:hover {
  transform: translateY(-2px);
}

.color-card.selected {
  border-color: var(--accent);
}

.color-card .piece {
  font-size: 3rem;
  line-height: 1;
}

.color-card .label {
  display: block;
  margin-top: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.difficulty-choices {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.diff-btn {
  background: var(--card-bg);
  border: 2px solid transparent;
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 0.6rem 1rem;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  transition: border-color 0.2s, transform 0.15s;
  text-align: center;
  color: var(--text);
  font-family: inherit;
}

.diff-btn:hover {
  transform: translateY(-1px);
}

.diff-btn.selected {
  border-color: var(--accent);
  background: #eef2ff;
}

.diff-btn .diff-name {
  display: block;
  font-weight: 600;
}

.diff-btn .diff-desc {
  display: block;
  font-size: 0.75rem;
  color: var(--text-light);
  margin-top: 0.15rem;
}

.start-btn {
  display: block;
  width: 100%;
  padding: 0.9rem;
  border: none;
  border-radius: var(--radius);
  background: var(--accent);
  color: white;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.2s;
}

.start-btn:hover:not(:disabled) {
  background: var(--accent-hover);
}

.start-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Game Screen */
.game-screen {
  display: none;
  max-width: 600px;
  margin: 0 auto;
  padding: 0 1rem 2rem;
}

.game-screen.active {
  display: block;
}

.setup-screen.hidden {
  display: none;
}

/* Status Bar */
.status-bar {
  text-align: center;
  padding: 0.5rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: 8px;
  background: var(--card-bg);
  box-shadow: var(--shadow);
}

.status-bar.check {
  color: var(--orange);
  background: #fffaf0;
}

.status-bar.thinking {
  color: var(--accent);
}

/* Captured Pieces */
.captured-pieces {
  display: flex;
  min-height: 1.75rem;
  align-items: center;
  padding: 0.15rem 0.25rem;
  font-size: 1.25rem;
  gap: 1px;
  flex-wrap: wrap;
}

.captured-pieces.top {
  margin-bottom: 0.25rem;
}

.captured-pieces.bottom {
  margin-top: 0.25rem;
}

/* Board Container */
.board-container {
  position: relative;
  width: 100%;
  max-width: 560px;
  min-width: 280px;
  margin: 0 auto;
}

.board-container .cg-wrap {
  width: 100%;
  padding-bottom: 100%;
}

/* Illegal Move Tooltip */
.illegal-tooltip {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0, 0, 0, 0.88);
  color: white;
  padding: 0.75rem 1.1rem;
  border-radius: 10px;
  font-size: 0.9rem;
  line-height: 1.4;
  text-align: center;
  max-width: 260px;
  z-index: 100;
  pointer-events: none;
  animation: tooltipIn 0.2s ease-out;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

@keyframes tooltipIn {
  from { opacity: 0; transform: translate(-50%, -50%) scale(0.9); }
  to { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

/* Controls */
.game-controls {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.ctrl-btn {
  padding: 0.55rem 1rem;
  border: none;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.2s;
}

.ctrl-btn.hint {
  background: var(--green);
  color: white;
}

.ctrl-btn.hint:hover {
  background: var(--green-hover);
}

.ctrl-btn.hint.active {
  background: var(--orange);
}

.ctrl-btn.new-game {
  background: var(--accent);
  color: white;
}

.ctrl-btn.new-game:hover {
  background: var(--accent-hover);
}

/* Move History */
.move-history {
  margin-top: 0.75rem;
  background: var(--card-bg);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 0.6rem 0.75rem;
  max-height: 120px;
  overflow-y: auto;
  font-size: 0.8rem;
  font-family: 'SF Mono', 'Fira Code', monospace;
  line-height: 1.6;
  color: var(--text-light);
}

.move-history .move-number {
  color: var(--text);
  font-weight: 600;
}

/* Promotion Modal */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 200;
  align-items: center;
  justify-content: center;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 1.5rem;
  text-align: center;
  max-width: 340px;
  width: 90%;
}

.modal h2 {
  font-size: 1.15rem;
  margin-bottom: 1rem;
}

.promo-pieces {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}

.promo-piece {
  width: 60px;
  height: 60px;
  background: var(--card-bg);
  border: 2px solid #e2e8f0;
  border-radius: 8px;
  font-size: 2.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 0.15s, transform 0.15s;
}

.promo-piece:hover {
  border-color: var(--accent);
  transform: scale(1.08);
}

/* Game Over Modal */
.game-over-modal .result {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.game-over-modal .result-detail {
  color: var(--text-light);
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
}

.modal-actions {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
}

.modal-actions .ctrl-btn {
  min-width: 120px;
}

/* Chessground overrides */
.cg-wrap {
  user-select: none;
}

/* Green highlight for legal squares */
.cg-wrap square.move-dest {
  background: none;
}

.cg-wrap square.move-dest::after {
  content: '';
  display: block;
  width: 33%;
  height: 33%;
  border-radius: 50%;
  background: rgba(56, 161, 105, 0.5);
  margin: auto;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

/* Responsive */
@media (max-width: 400px) {
  .chess-header h1 {
    font-size: 1.25rem;
  }

  .diff-btn {
    padding: 0.5rem 0.7rem;
    font-size: 0.8rem;
  }

  .ctrl-btn {
    padding: 0.5rem 0.75rem;
    font-size: 0.8rem;
  }
}