:root {
  --bg: #0f1117;
  --bg2: #161b22;
  --bg3: #1c2333;
  --border: #2d333b;
  --text: #e6edf3;
  --text2: #8b949e;
  --accent: #58a6ff;
  --green: #3fb950;
  --red: #f85149;
  --yellow: #d29922;
  --sq-light: #f0d9b5;
  --sq-dark: #b58863;
  --highlight: rgba(255, 255, 0, 0.4);
  --check: rgba(255, 0, 0, 0.5);
  --move-dot: rgba(0, 0, 0, 0.2);
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --mono: 'SF Mono', SFMono-Regular, Consolas, 'Liberation Mono', Menlo, monospace;
}

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

.hidden { display: none !important; }

.screen { min-height: 100vh; display: flex; align-items: center; justify-content: center; }

/* ── Landing ──────────────────────── */
.card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px 32px;
  width: 380px;
  max-width: 92vw;
  text-align: center;
}

.card h1 { font-size: 2rem; margin-bottom: 4px; }
.subtitle { color: var(--text2); margin-bottom: 28px; font-size: 0.9rem; }

.form-group { margin-bottom: 20px; text-align: left; }
.form-group label { display: block; font-size: 0.8rem; color: var(--text2); margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.05em; }

.btn-group { display: flex; gap: 6px; flex-wrap: wrap; }
.btn-toggle {
  flex: 1;
  min-width: 0;
  padding: 8px 4px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg3);
  color: var(--text2);
  font-size: 0.82rem;
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font);
}
.btn-toggle:hover { border-color: var(--accent); color: var(--text); }
.btn-toggle.active { background: var(--accent); color: #000; border-color: var(--accent); font-weight: 600; }

.btn-primary {
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: 10px;
  background: var(--accent);
  color: #000;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: opacity 0.15s;
}
.btn-primary:hover { opacity: 0.85; }

.btn-secondary {
  padding: 12px 20px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg3);
  color: var(--text);
  font-size: 0.95rem;
  cursor: pointer;
  font-family: var(--font);
  transition: border-color 0.15s;
}
.btn-secondary:hover { border-color: var(--accent); }

.divider { display: flex; align-items: center; gap: 12px; margin: 20px 0; color: var(--text2); font-size: 0.85rem; }
.divider::before, .divider::after { content: ''; flex: 1; height: 1px; background: var(--border); }

.join-group { display: flex; gap: 8px; }
.join-group input {
  flex: 1;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg3);
  color: var(--text);
  font-size: 1rem;
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  outline: none;
}
.join-group input:focus { border-color: var(--accent); }
.join-group input::placeholder { text-transform: none; letter-spacing: 0; color: var(--text2); }

/* ── Game Layout ──────────────────── */
#game { align-items: stretch; justify-content: stretch; }

.game-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  grid-template-rows: auto 1fr auto;
  width: 100%;
  height: 100vh;
  gap: 0;
}

.top-bar, .bottom-bar {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
}
.bottom-bar { border-bottom: none; border-top: 1px solid var(--border); }

.opponent-info, .player-info { flex: 1; display: flex; align-items: center; gap: 8px; min-width: 0; }
.opponent-info span, .player-info span { font-size: 0.9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.status { font-size: 0.75rem; color: var(--yellow); }
.spectators { font-size: 0.75rem; color: var(--text2); }

.top-clock, .bottom-clock {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 14px;
  font-family: var(--mono);
  font-size: 1.3rem;
  font-weight: 600;
  min-width: 90px;
  text-align: center;
}
.top-clock.active, .bottom-clock.active { border-color: var(--green); color: var(--green); }
.top-clock.low, .bottom-clock.low { color: var(--red); border-color: var(--red); }

.captured { display: flex; gap: 1px; font-size: 0.9rem; min-width: 60px; flex-wrap: wrap; }

/* ── Board ────────────────────────── */
.board-container {
  grid-column: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background: var(--bg);
  position: relative;
  overflow: hidden;
}

.board {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  width: min(calc(100vh - 160px), calc(100vw - 320px));
  height: min(calc(100vh - 160px), calc(100vw - 320px));
  max-width: 600px;
  max-height: 600px;
  border: 2px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

.sq {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0;
  cursor: pointer;
}
.sq.light { background: var(--sq-light); }
.sq.dark { background: var(--sq-dark); }
.sq.highlight { background: var(--highlight) !important; }
.sq.check { background: var(--check) !important; }
.sq.last-from, .sq.last-to { box-shadow: inset 0 0 0 3px rgba(255, 255, 0, 0.6); }

.piece {
  font-size: min(calc((min(calc(100vh - 160px), calc(100vw - 320px)) / 8) * 0.85), 56px);
  line-height: 1;
  cursor: grab;
  z-index: 2;
  filter: drop-shadow(1px 1px 2px rgba(0,0,0,0.3));
  transition: transform 0.08s;
  pointer-events: none;
}
.piece.dragging { cursor: grabbing; transform: scale(1.15); z-index: 10; }

.move-dot {
  position: absolute;
  width: 28%;
  height: 28%;
  border-radius: 50%;
  background: var(--move-dot);
  pointer-events: none;
  z-index: 1;
}
.sq.capture-dot::after {
  content: '';
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  border: 4px solid var(--move-dot);
  pointer-events: none;
}

/* ── Promotion picker ─────────────── */
.promo-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.promo-picker {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  display: flex;
  gap: 8px;
}
.promo-piece {
  font-size: 48px;
  padding: 8px 12px;
  cursor: pointer;
  border-radius: 8px;
  transition: background 0.15s;
}
.promo-piece:hover { background: var(--bg3); }

/* ── Sidebar ──────────────────────── */
.sidebar {
  grid-column: 2;
  grid-row: 2 / 4;
  background: var(--bg2);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 12px;
  overflow: hidden;
}

.room-info { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; }
.room-code {
  flex: 1;
  font-family: var(--mono);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.btn-icon {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 8px;
  cursor: pointer;
  font-size: 1rem;
  color: var(--text);
  transition: border-color 0.15s;
}
.btn-icon:hover { border-color: var(--accent); }

.move-list {
  flex: 1;
  overflow-y: auto;
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--text2);
  padding: 8px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-bottom: 12px;
}
.move-row { display: flex; padding: 2px 8px; }
.move-num { width: 32px; color: var(--text2); flex-shrink: 0; }
.move-w, .move-b { flex: 1; cursor: default; }
.move-w.active, .move-b.active { color: var(--accent); font-weight: 600; }

.game-actions { display: flex; gap: 8px; margin-bottom: 8px; }
.btn-action {
  flex: 1;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg3);
  color: var(--text);
  font-size: 0.85rem;
  cursor: pointer;
  font-family: var(--font);
  transition: border-color 0.15s;
}
.btn-action:hover { border-color: var(--accent); }
.btn-action.btn-danger:hover { border-color: var(--red); color: var(--red); }

.draw-offer {
  background: var(--bg3);
  border: 1px solid var(--yellow);
  border-radius: 8px;
  padding: 10px;
  margin-bottom: 8px;
  text-align: center;
}
.draw-offer p { font-size: 0.85rem; margin-bottom: 8px; }
.btn-sm { padding: 6px 12px; font-size: 0.8rem; width: auto; }

.settings { font-size: 0.8rem; color: var(--text2); display: flex; flex-direction: column; gap: 4px; }
.settings label { display: flex; align-items: center; gap: 6px; cursor: pointer; }
.settings input { accent-color: var(--accent); }

/* ── Overlay ──────────────────────── */
.overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
  border-radius: 4px;
}
.overlay-content {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  text-align: center;
  max-width: 320px;
}
.overlay-content h2 { margin-bottom: 8px; }
.overlay-content p { color: var(--text2); margin-bottom: 20px; font-size: 0.9rem; }
.overlay-actions { display: flex; gap: 8px; }

/* ── Responsive ───────────────────── */
@media (max-width: 768px) {
  .game-layout {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr auto auto;
  }
  .sidebar {
    grid-column: 1;
    grid-row: 4;
    border-left: none;
    border-top: 1px solid var(--border);
    max-height: 200px;
  }
  .board {
    width: min(calc(100vw - 16px), calc(100vh - 280px));
    height: min(calc(100vw - 16px), calc(100vh - 280px));
  }
  .top-clock, .bottom-clock { font-size: 1.1rem; padding: 4px 10px; min-width: 70px; }
  .captured { display: none; }
}

@media (max-width: 480px) {
  .board {
    width: calc(100vw - 8px);
    height: calc(100vw - 8px);
  }
  .piece { font-size: calc((100vw - 8px) / 8 * 0.85); }
}

/* ── Scrollbar ────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg2); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text2); }