/* ── Nav ────────────────────────────────────────────────────── */
.site-nav {
  display: flex;
  gap: 6px;
  padding: 10px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 4px;
}

.nav-link {
  padding: 6px 14px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.4px;
  color: var(--text-dim);
  text-decoration: none;
  transition: all 0.2s;
}

.nav-link:hover  { color: var(--text); background: var(--surface2); }
.nav-link.active { color: var(--accent); background: var(--accent-dim); }

/* ── Chess board grid ───────────────────────────────────────── */
.chess-board {
  display: grid;
  grid-template-columns: repeat(8, 64px);
  grid-template-rows:    repeat(8, 64px);
  border: 2px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
  user-select: none;
  flex-shrink: 0;
}

.chess-board.mini {
  grid-template-columns: repeat(8, 36px);
  grid-template-rows:    repeat(8, 36px);
}

/* ── Squares ────────────────────────────────────────────────── */
.chess-square {
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  position: relative;   /* required for ::after highlight overlays */
}

.chess-board.mini .chess-square { cursor: default; }

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

/* ── Piece sprites ──────────────────────────────────────────── */
.chess-square img {
  width: 88%;
  height: 88%;
  display: block;
  pointer-events: none;   /* clicks hit the square, not the image */
  user-select: none;
}

/* ── Selected piece highlight (Chess.com green-yellow) ──────── */
.chess-square.sel { background: #829769 !important; }
.chess-square.light.sel { background: #cdd16e !important; }

/* ── Legal-move dot (empty destination) ─────────────────────── */
.chess-square.legal::after {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 32%;
  height: 32%;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.20);
  pointer-events: none;
  z-index: 2;
}

/* ── Legal-capture ring (destination has an enemy piece) ─────── */
.chess-square.legal-cap::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 50%;
  box-shadow: inset 0 0 0 5px rgba(0, 0, 0, 0.22);
  pointer-events: none;
  z-index: 2;
}

/* ── Last-move / analysis highlights ───────────────────────── */
.chess-square.hl-from    { background: rgba(246,246,105,0.55) !important; }
.chess-square.hl-to      { background: rgba(246,246,105,0.55) !important; }
.chess-square.hl-mistake { background: rgba(208,91,91,0.50)   !important; }
.chess-square.hl-better  { background: rgba(76,175,125,0.45)  !important; }

/* ── Game status ────────────────────────────────────────────── */
.game-status {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 0.5px;
  padding: 6px 0;
  text-align: center;
}

/* ── Move entry in log ──────────────────────────────────────── */
.move-entry {
  padding: 3px 0;
  border-bottom: 1px solid color-mix(in srgb, var(--border) 40%, transparent);
  color: var(--text-dim);
}
.move-entry:last-child { border-bottom: none; color: var(--text); }

/* ── Mistake badge ──────────────────────────────────────────── */
.mistake-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1px;
}

.mistake-badge.blunder    { background: rgba(208,91,91,0.25);  color: #e07070; border: 1px solid #d05b5b; }
.mistake-badge.mistake    { background: rgba(230,150,60,0.25); color: #e09660; border: 1px solid #d07030; }
.mistake-badge.inaccuracy { background: rgba(201,168,76,0.25); color: #c9a84c; border: 1px solid #a08030; }

/* ── Mistake slide-up panel ─────────────────────────────────── */
#mistake-panel {
  position: fixed;
  bottom: -100%;
  left: 0; right: 0;
  background: var(--surface);
  border-top: 2px solid var(--critic-color);
  box-shadow: 0 -8px 40px rgba(0,0,0,0.6);
  padding: 16px 24px;
  z-index: 100;
  transition: bottom 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
  max-height: 55vh;
  overflow-y: auto;
}

#mistake-panel.visible { bottom: 0; }

.mistake-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

/* ── Practice page tabs ─────────────────────────────────────── */
.tab-bar {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--border);
  padding: 0 16px;
  background: var(--surface2);
}

.tab-btn {
  padding: 10px 18px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-dim);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: -1px;
}

.tab-btn:hover  { color: var(--text); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }

/* ── Puzzle cards ───────────────────────────────────────────── */
.puzzle-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: border-color 0.2s;
}

.puzzle-card.solved { border-color: var(--success-color); }
.puzzle-card.failed { border-color: var(--critic-color); }

.puzzle-game-header {
  padding: 10px 16px;
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-dim);
  border-bottom: 1px solid var(--border);
}

.puzzle-body {
  padding: 16px;
  display: flex;
  gap: 20px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.puzzle-info { flex: 1; min-width: 200px; }

.puzzle-theme {
  display: inline-block;
  padding: 2px 8px;
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: 4px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.puzzle-turn {
  font-size: 12px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.puzzle-hint {
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 10px;
}

.puzzle-feedback {
  font-size: 12px;
  line-height: 1.6;
  margin-top: 10px;
  padding: 8px 10px;
  border-radius: 6px;
  display: none;
}

.puzzle-feedback.visible         { display: block; }
.puzzle-feedback.correct         { background: rgba(76,175,125,0.15); color: var(--success-color); border: 1px solid rgba(76,175,125,0.3); }
.puzzle-feedback.wrong           { background: rgba(208,91,91,0.12);  color: #e07070;              border: 1px solid rgba(208,91,91,0.3); }
.puzzle-feedback.revealed        { background: var(--accent-dim); color: var(--accent); border: 1px solid rgba(90,144,200,0.3); }

.puzzle-tries {
  font-size: 11px;
  color: var(--text-dim);
  margin-top: 6px;
}

/* ── Opening lines ──────────────────────────────────────────── */
.opening-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.opening-header {
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  cursor: pointer;
}

.opening-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
}

.opening-color-pill {
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 10px;
  font-weight: 700;
}

.opening-color-pill.white { background: rgba(255,255,255,0.1); color: #ddd; }
.opening-color-pill.black { background: rgba(0,0,0,0.3);       color: #aaa; border: 1px solid #444; }

.opening-body { padding: 14px 16px; }

.opening-moves {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 10px;
}

.opening-move-chip {
  padding: 3px 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text);
  cursor: default;
  transition: border-color 0.15s;
}

.opening-description { font-size: 12px; line-height: 1.6; color: var(--text-dim); margin-bottom: 6px; }
.opening-key-ideas   { font-size: 12px; color: var(--accent); font-style: italic; }

/* ── Loading spinner ────────────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  vertical-align: middle;
  margin-right: 8px;
}

@keyframes spin { to { transform: rotate(360deg); } }