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

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: #0d1117;
  color: #c9d1d9;
  min-height: 100vh;
  line-height: 1.5;
}

/* ─── Header ─────────────────────────────────────────────────────────────────── */
header {
  background: #161b22;
  border-bottom: 1px solid #30363d;
  padding: 16px 32px;
  display: flex;
  align-items: center;
  gap: 16px;
}

header h1 { font-size: 1.6rem; color: #f0f6fc; }
header .subtitle { color: #7d8590; font-size: 0.9rem; }

/* ─── Layout ─────────────────────────────────────────────────────────────────── */
main { max-width: 1200px; margin: 0 auto; padding: 20px; }

.game-container {
  display: flex;
  gap: 20px;
  margin-bottom: 20px;
  align-items: flex-start;
  flex-wrap: wrap;
}

/* ─── Chess Board ────────────────────────────────────────────────────────────── */
.board-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.board-wrapper {
  display: flex;
  align-items: center;
  gap: 4px;
}

.chess-board {
  display: grid;
  grid-template-columns: repeat(8, 66px);
  grid-template-rows:    repeat(8, 66px);
  border: 2px solid #30363d;
  border-radius: 4px;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0,0,0,0.6);
}

.square {
  width: 66px; height: 66px;
  display: flex; align-items: center; justify-content: center;
  font-size: 40px;
  cursor: pointer;
  position: relative;
  transition: filter 0.1s;
  user-select: none;
}

.square.light { background: #f0d9b5; }
.square.dark  { background: #b58863; }

.square:hover { filter: brightness(1.12); }

.square.selected {
  background: #7fc97f !important;
  box-shadow: inset 0 0 0 3px #258a25;
}

/* Legal move dots */
.square.legal-move:not(.has-piece)::after {
  content: '';
  position: absolute;
  width: 22px; height: 22px;
  background: rgba(0,0,0,0.28);
  border-radius: 50%;
  pointer-events: none;
}

/* Legal capture ring */
.square.legal-move.has-piece::after {
  content: '';
  position: absolute;
  inset: 0;
  border: 5px solid rgba(0,0,0,0.28);
  border-radius: 50%;
  pointer-events: none;
}

.square.last-move-from { background: #cdd26a !important; }
.square.last-move-to   { background: #aaa23a !important; }

.rank-labels {
  display: flex; flex-direction: column;
  height: 528px; /* 8 × 66px */
}
.rank-labels span {
  display: flex; align-items: center; justify-content: center;
  height: 66px; width: 18px;
  font-size: 0.7rem; color: #7d8590; font-weight: bold;
}

.file-labels {
  display: flex;
  width: 528px;
}
.file-labels span {
  display: flex; align-items: center; justify-content: center;
  width: 66px; height: 18px;
  font-size: 0.7rem; color: #7d8590; font-weight: bold;
}

.game-status {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 8px;
  padding: 10px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  color: #e6edf3;
  min-width: 300px;
  text-align: center;
}

/* ─── Control Panel ──────────────────────────────────────────────────────────── */
.control-panel {
  flex: 1;
  min-width: 270px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.panel-section {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 10px;
  padding: 14px;
}

.panel-section h3 {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: #7d8590;
  margin-bottom: 10px;
}

/* Buttons */
.btn-row { display: flex; gap: 6px; flex-wrap: wrap; }

.mode-btn, .algo-btn, .control-btn {
  flex: 1;
  padding: 8px 10px;
  border: 1px solid #30363d;
  border-radius: 6px;
  background: #21262d;
  color: #c9d1d9;
  cursor: pointer;
  font-size: 0.82rem;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  white-space: nowrap;
}

.mode-btn:hover, .algo-btn:hover, .control-btn:hover {
  background: #2d333b;
  color: #f0f6fc;
}

.mode-btn.active {
  background: #1f6feb;
  border-color: #388bfd;
  color: #fff;
}

.algo-btn {
  display: flex; align-items: center; gap: 8px;
  text-align: left; min-width: 100%;
  padding: 10px 12px;
  margin-bottom: 4px;
}

.algo-btn.active {
  background: #0d4429;
  border-color: #238636;
  color: #3fb950;
}

.algo-icon { font-size: 1rem; }

.algo-btn .algo-desc {
  font-size: 0.72rem;
  color: #7d8590;
  margin-top: 2px;
  display: block;
}

.algo-btn.active .algo-desc { color: #7ee787; }

.control-btn.danger {
  background: #21262d;
  border-color: #30363d;
}
.control-btn.danger:hover { background: #490202; border-color: #f85149; color: #f85149; }

/* Depth Slider */
.depth-control {
  display: flex; align-items: center; gap: 12px;
}
.depth-control input[type=range] {
  flex: 1;
  accent-color: #1f6feb;
  height: 4px;
}
#depthValue {
  font-size: 1.3rem; font-weight: bold; color: #1f6feb; min-width: 24px;
}

/* Stats */
.stats-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 8px;
}
.stat-item {
  background: #0d1117;
  border: 1px solid #30363d;
  border-radius: 6px;
  padding: 8px 10px;
}
.stat-label { display: block; font-size: 0.68rem; color: #7d8590; margin-bottom: 3px; }
.stat-value { display: block; font-size: 1rem; font-weight: bold; color: #79c0ff; }

/* ─── Comparison Section ─────────────────────────────────────────────────────── */
.comparison-section {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 20px;
}

.comparison-section h2 { font-size: 1.1rem; color: #f0f6fc; margin-bottom: 14px; }

.comparison-layout {
  display: flex; gap: 20px; align-items: flex-start; flex-wrap: wrap;
}

.comparison-table {
  flex: 1; border-collapse: collapse; font-size: 0.88rem; min-width: 400px;
}
.comparison-table th {
  background: #0d1117;
  padding: 10px 12px;
  text-align: left;
  color: #7d8590;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid #30363d;
}
.comparison-table td {
  padding: 10px 12px;
  border-bottom: 1px solid #21262d;
}
.comparison-table tr:hover td { background: #1c2128; }
.comparison-table code {
  font-family: 'Courier New', monospace;
  background: #0d1117;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85rem;
}
.winner-cell { color: #3fb950; font-weight: bold; }
.empty-row { text-align: center; color: #7d8590; padding: 20px !important; font-style: italic; }

/* Chart */
.chart-container {
  background: #0d1117;
  border: 1px solid #30363d;
  border-radius: 8px;
  padding: 10px;
  min-width: 340px;
}

/* ─── Log ─────────────────────────────────────────────────────────────────────── */
.log-section {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 10px;
  padding: 16px;
}

.log-header {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 10px;
}
.log-header h2 { font-size: 1rem; color: #f0f6fc; }
.log-header button {
  padding: 4px 12px;
  background: #21262d; border: 1px solid #30363d; border-radius: 5px;
  color: #7d8590; cursor: pointer; font-size: 0.8rem;
}
.log-header button:hover { background: #2d333b; color: #c9d1d9; }

.log-content {
  max-height: 220px; overflow-y: auto;
  display: flex; flex-direction: column; gap: 3px;
}

.log-entry {
  padding: 5px 10px;
  border-radius: 4px;
  font-size: 0.8rem;
  font-family: 'Courier New', monospace;
}

.log-entry.info     { background: #0d1117; color: #7d8590; }
.log-entry.success  { background: #0d3a20; color: #3fb950; }
.log-entry.warning  { background: #2d2208; color: #e3b341; }
.log-entry.error    { background: #3d0c0c; color: #f85149; }
.log-entry.minimax  { background: #0d1433; color: #79c0ff; border-left: 3px solid #388bfd; }
.log-entry.alphabeta{ background: #0d2a0d; color: #7ee787; border-left: 3px solid #238636; }
.log-entry.astar    { background: #2a1a0a; color: #ffa657; border-left: 3px solid #d29922; }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #0d1117; }
::-webkit-scrollbar-thumb { background: #30363d; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #3d444d; }