:root {
  --bg-1: #1a1410;
  --bg-2: #251c15;
  --board-1: #e6b97a;
  --board-2: #c98c4b;
  --board-edge: #6b3a17;
  --line: #3b2310;
  --text: #f3e7d3;
  --text-dim: #b8a98e;
  --accent: #d4a256;
  --accent-2: #f0c97a;
  --danger: #c84e3b;
  --warn: #b87d2c;
  --black-stone-1: #4a4a4a;
  --black-stone-2: #050505;
  --white-stone-1: #ffffff;
  --white-stone-2: #c8c0b4;
  --panel: rgba(30, 22, 16, 0.78);
  --panel-border: rgba(212, 162, 86, 0.25);
  --shadow: 0 18px 48px rgba(0, 0, 0, 0.55);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(212, 162, 86, 0.12), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, rgba(200, 78, 59, 0.08), transparent 60%),
    linear-gradient(180deg, var(--bg-1), var(--bg-2));
  background-attachment: fixed;
}

.app {
  max-width: 1280px;
  margin: 0 auto;
  padding: 28px 32px 40px;
}

.topbar {
  text-align: center;
  margin-bottom: 22px;
}

.topbar h1 {
  margin: 0;
  font-size: 32px;
  letter-spacing: 6px;
  font-weight: 600;
  background: linear-gradient(180deg, var(--accent-2), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.topbar .subtitle {
  margin-top: 6px;
  font-size: 13px;
  color: var(--text-dim);
  letter-spacing: 2px;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 28px;
  align-items: start;
}

@media (max-width: 1024px) {
  .layout { grid-template-columns: 1fr; }
}

/* ---------- Board panel ---------- */

.board-panel {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  padding: 20px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(6px);
}

.status-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
  padding: 0 4px;
  font-size: 14px;
  color: var(--text-dim);
}

.turn-indicator {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  color: var(--text);
}

.stone-mini {
  display: inline-block;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, #6a6a6a, #050505 70%);
  box-shadow: inset 0 -2px 4px rgba(0,0,0,0.5), 0 1px 2px rgba(0,0,0,0.6);
  transition: background 0.25s ease;
}
.stone-mini.white {
  background: radial-gradient(circle at 30% 30%, #ffffff, #c8c0b4 70%);
  box-shadow: inset 0 -2px 4px rgba(0,0,0,0.15), 0 1px 2px rgba(0,0,0,0.4);
}

.move-count { font-variant-numeric: tabular-nums; }

.board-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: 12px;
  overflow: hidden;
  box-shadow:
    inset 0 0 0 1px rgba(0,0,0,0.25),
    0 12px 30px rgba(0,0,0,0.55);
}

#board {
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
  /* Touch: suppress double-tap-zoom and let single taps register as clicks */
  touch-action: manipulation;
  -webkit-user-select: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

[hidden] { display: none !important; }

.winner-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.25s ease;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.winner-card {
  background: linear-gradient(180deg, #2a1f17, #1a1410);
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  padding: 28px 36px;
  text-align: center;
  box-shadow: var(--shadow);
  animation: pop 0.3s cubic-bezier(.2,.8,.3,1.2);
}
@keyframes pop { from { transform: scale(0.92); opacity: 0; } to { transform: scale(1); opacity: 1; } }

.winner-title {
  font-size: 28px;
  letter-spacing: 4px;
  background: linear-gradient(180deg, var(--accent-2), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 6px;
}
.winner-title.lose {
  background: linear-gradient(180deg, #e8a193, var(--danger));
  -webkit-background-clip: text;
  background-clip: text;
}
.winner-sub { color: var(--text-dim); font-size: 13px; margin-bottom: 18px; }
.winner-actions { display: flex; gap: 10px; justify-content: center; }

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
  padding: 4px;
}

/* ---------- Buttons ---------- */

.btn {
  appearance: none;
  border: 1px solid var(--panel-border);
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(0,0,0,0.18));
  color: var(--text);
  padding: 9px 16px;
  border-radius: 8px;
  font-size: 14px;
  letter-spacing: 1px;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.15s ease, border-color 0.15s ease;
}
.btn:hover { border-color: var(--accent); background: linear-gradient(180deg, rgba(212,162,86,0.12), rgba(0,0,0,0.18)); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn.primary { background: linear-gradient(180deg, #d4a256, #a87a35); border-color: #d4a256; color: #1a1410; font-weight: 600; }
.btn.primary:hover { background: linear-gradient(180deg, #f0c97a, #c89548); }
.btn.warn { color: #f3c98a; }
.btn.danger { color: #ff9c8c; border-color: rgba(200, 78, 59, 0.4); }
.btn.danger:hover { background: rgba(200, 78, 59, 0.15); border-color: var(--danger); }
.btn.small { padding: 6px 10px; font-size: 12px; }

/* ---------- Side panel ---------- */

.side-panel {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  padding: 16px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(6px);
  max-height: 760px;
  display: flex;
  flex-direction: column;
}

.tabs {
  display: flex;
  gap: 6px;
  border-bottom: 1px solid var(--panel-border);
  margin-bottom: 12px;
  padding-bottom: 8px;
}
.tab {
  appearance: none;
  background: transparent;
  border: none;
  color: var(--text-dim);
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 14px;
  letter-spacing: 1px;
  cursor: pointer;
  transition: color 0.15s, background 0.15s;
}
.tab:hover { color: var(--text); }
.tab.active {
  color: #1a1410;
  background: linear-gradient(180deg, var(--accent-2), var(--accent));
  font-weight: 600;
}

.tab-pane {
  flex: 1;
  overflow-y: auto;
  padding-right: 4px;
}
.tab-pane::-webkit-scrollbar { width: 6px; }
.tab-pane::-webkit-scrollbar-thumb { background: rgba(212, 162, 86, 0.3); border-radius: 3px; }

.moves-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px;
}
.moves-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 6px;
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  background: rgba(255, 255, 255, 0.02);
  cursor: pointer;
  transition: background 0.12s;
}
.moves-list li:hover { background: rgba(212, 162, 86, 0.1); }
.moves-list li.last { background: rgba(212, 162, 86, 0.18); }
.moves-list .idx { color: var(--text-dim); width: 28px; }
.moves-list .dot {
  width: 12px; height: 12px; border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, #6a6a6a, #050505 70%);
  box-shadow: inset 0 -1px 2px rgba(0,0,0,0.5);
}
.moves-list .dot.white {
  background: radial-gradient(circle at 30% 30%, #ffffff, #c8c0b4 70%);
  box-shadow: inset 0 -1px 2px rgba(0,0,0,0.2);
}

.empty-hint {
  color: var(--text-dim);
  font-size: 13px;
  text-align: center;
  padding: 30px 0;
  opacity: 0.7;
}

.history-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  padding: 0 4px;
  font-size: 13px;
  color: var(--text-dim);
}

.history-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.history-list li {
  background: rgba(255,255,255,0.025);
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 10px 12px;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}
.history-list li:hover { background: rgba(212, 162, 86, 0.1); border-color: var(--panel-border); }
.history-row1 {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}
.history-winner {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
}
.history-row2 {
  display: flex;
  justify-content: space-between;
  margin-top: 4px;
  font-size: 12px;
  color: var(--text-dim);
  font-variant-numeric: tabular-nums;
}
.history-actions {
  display: flex;
  gap: 6px;
  margin-top: 8px;
}

/* ---------- Replay bar ---------- */

.replay-bar {
  margin-top: 18px;
  background: var(--panel);
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  box-shadow: var(--shadow);
}
.replay-info { display: flex; flex-direction: column; gap: 2px; font-size: 13px; color: var(--text-dim); }
.replay-info strong { color: var(--accent-2); font-size: 14px; letter-spacing: 2px; }
.replay-controls { display: flex; align-items: center; gap: 6px; }
.replay-progress {
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  padding: 0 8px;
  color: var(--text-dim);
}

/* ---------- Mode switch (capsule pill) ---------- */

.mode-switch-wrap {
  display: flex;
  justify-content: center;
  margin: 0 0 22px;
}

.mode-switch {
  display: inline-flex;
  background: rgba(20, 14, 10, 0.65);
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  padding: 4px;
  gap: 2px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.mode-option {
  background: transparent;
  border: none;
  color: var(--text-dim);
  font-family: inherit;
  font-size: 13px;
  letter-spacing: 4px;
  padding: 8px 22px;
  cursor: pointer;
  border-radius: 999px;
  transition: background 0.18s, color 0.18s;
}

.mode-option:hover:not(.active):not(:disabled) {
  color: var(--text);
}

.mode-option.active {
  background: linear-gradient(180deg, var(--accent-2), var(--accent));
  color: var(--bg-1);
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(212, 162, 86, 0.3);
}

.mode-option:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

/* ---------- Winner overlay extras ---------- */

.rematch-hint {
  margin-top: 14px;
  font-size: 13px;
  color: var(--accent-2);
  text-align: center;
  letter-spacing: 0.5px;
  min-height: 18px;
}

/* ---------- Online mode ---------- */

.online-status-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  margin-bottom: 12px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  font-size: 14px;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.5px;
}

.online-status-text { font-weight: 500; }

.modal-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(8, 5, 2, 0.66);
  backdrop-filter: blur(4px);
  z-index: 100;
}

.modal-card {
  width: min(420px, calc(100vw - 32px));
  background: linear-gradient(180deg, #2a2018, #1c150f);
  border: 1px solid var(--accent);
  border-radius: 16px;
  padding: 24px 28px 20px;
  box-shadow: var(--shadow);
}

.modal-card h2 {
  margin: 0 0 4px;
  color: var(--accent-2);
  font-size: 22px;
  letter-spacing: 4px;
  font-weight: 600;
}

.modal-subtitle {
  margin: 0 0 18px;
  color: var(--text-dim);
  font-size: 13px;
}

.modal-hint {
  margin: 8px 0 14px;
  color: var(--text-dim);
  font-size: 13px;
  text-align: center;
}

.btn.block {
  width: 100%;
  display: block;
  padding: 12px 18px;
  font-size: 15px;
}

.modal-divider {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 16px 0;
  color: var(--text-dim);
  font-size: 12px;
}

.modal-divider::before,
.modal-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--panel-border);
}

.modal-row {
  display: flex;
  gap: 10px;
  align-items: center;
}

.modal-input {
  flex: 1;
  padding: 10px 14px;
  font-size: 22px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 8px;
  text-align: center;
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  color: var(--accent-2);
  outline: none;
  transition: border-color 0.15s;
}

.modal-input:focus { border-color: var(--accent); }
.modal-input.invalid { border-color: var(--danger); animation: shake 0.4s; }

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

.modal-actions {
  margin-top: 18px;
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

.room-id-display {
  margin: 14px 0 6px;
  text-align: center;
  font-size: 48px;
  font-weight: 700;
  letter-spacing: 12px;
  color: var(--accent-2);
  font-variant-numeric: tabular-nums;
  text-shadow: 0 4px 18px rgba(212, 162, 86, 0.4);
}

/* ---------- Confirm modal ---------- */

#confirmModal {
  z-index: 150; /* above the winner overlay (z-index ~50) */
}

.modal-confirm {
  width: min(360px, calc(100vw - 32px));
}

.modal-confirm h2 {
  margin-bottom: 12px;
  letter-spacing: 3px;
}

/* ---------- Toasts ---------- */

#toastHost {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 200;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  padding: 10px 18px;
  border-radius: 10px;
  font-size: 13px;
  letter-spacing: 0.4px;
  background: rgba(40, 28, 18, 0.95);
  border: 1px solid var(--panel-border);
  color: var(--text);
  box-shadow: var(--shadow);
  opacity: 1;
  transition: opacity 0.3s, transform 0.3s;
  animation: toast-in 0.18s ease-out;
}

.toast-warn { border-color: var(--warn); color: var(--accent-2); }
.toast-error { border-color: var(--danger); color: #ffd6cf; }
.toast-fade { opacity: 0; transform: translateY(-8px); }

@keyframes toast-in {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- Mobile (≤ 640px) ---------- */

@media (max-width: 640px) {
  .app {
    padding:
      max(env(safe-area-inset-top, 8px), 8px)
      max(env(safe-area-inset-right, 6px), 6px)
      max(env(safe-area-inset-bottom, 16px), 16px)
      max(env(safe-area-inset-left, 6px), 6px);
  }

  .topbar { margin-bottom: 12px; }
  .topbar h1 { font-size: 22px; letter-spacing: 4px; }
  .topbar .subtitle { display: none; }

  .mode-switch-wrap { margin: 0 0 12px; }
  .mode-switch { padding: 3px; }
  .mode-option {
    padding: 6px 16px;
    font-size: 12px;
    letter-spacing: 2px;
  }

  /* Strip the panel chrome so the board fills nearly the whole width. */
  .board-panel {
    background: transparent;
    border: none;
    padding: 0;
    box-shadow: none;
    backdrop-filter: none;
    border-radius: 0;
  }

  .status-bar {
    margin-bottom: 8px;
    padding: 0 4px;
    font-size: 13px;
  }
  .turn-indicator { font-size: 14px; gap: 8px; }
  .stone-mini { width: 16px; height: 16px; }

  .board-wrap {
    border-radius: 6px;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.5);
  }

  .online-status-bar {
    margin-top: 10px;
    margin-bottom: 8px;
    padding: 8px 12px;
    font-size: 13px;
  }

  .controls {
    margin-top: 10px;
    gap: 6px;
    justify-content: center;
  }
  .btn {
    padding: 7px 12px;
    font-size: 13px;
    letter-spacing: 1px;
  }
  .btn.small { padding: 5px 10px; font-size: 12px; }

  /* Side panel (移动端不展示历史/手数 tabs，棋盘最大化) */
  .side-panel { display: none; }

  /* Modals shrink to fit narrow screens */
  .modal-card { padding: 18px 20px 14px; }
  .modal-card h2 { font-size: 18px; letter-spacing: 3px; }
  .modal-input {
    font-size: 20px;
    letter-spacing: 6px;
    padding: 8px 12px;
  }
  .room-id-display {
    font-size: 38px;
    letter-spacing: 8px;
  }

  /* Winner overlay card a touch tighter */
  .winner-card { padding: 22px 20px; }
  .winner-title { font-size: 22px; letter-spacing: 3px; }

  /* Toasts */
  #toastHost { top: 8px; }
  .toast { font-size: 12px; padding: 8px 14px; }
}

/* Phones with width below ~380px (older iPhone SE etc.) */
@media (max-width: 380px) {
  .app {
    padding: 6px 2px max(env(safe-area-inset-bottom, 12px), 12px);
  }
  .topbar h1 { font-size: 20px; letter-spacing: 3px; }
  .mode-option { padding: 5px 12px; }
  .btn { padding: 6px 9px; font-size: 12px; }
}