:root {
  --board: #e9c88a;
  --board-edge: #c79a55;
  --line: #6b4b1f;
  --bg: #14100b;
  --panel: #211a12;
  --text: #f1e6d2;
  --muted: #b09a78;
}

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: radial-gradient(800px 500px at 50% -10%, #2a2114, transparent), var(--bg);
  color: var(--text);
  display: flex;
  justify-content: center;
  padding: 18px;
  min-height: 100vh;
}

.app {
  width: 100%;
  max-width: 560px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.bar {
  display: flex;
  align-items: center;
  gap: 10px;
  justify-content: space-between;
}

.modes {
  display: flex;
  background: var(--panel);
  border: 1px solid #362a1c;
  border-radius: 10px;
  padding: 3px;
}

.seg {
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
}

.seg.active {
  background: #3b2d1c;
  color: var(--text);
}

.actions {
  display: flex;
  gap: 8px;
}

.icon-btn {
  width: 42px;
  height: 42px;
  font-size: 18px;
  border-radius: 10px;
  border: 1px solid #362a1c;
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
}

.icon-btn:hover {
  background: #2b2116;
}

.status {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
  padding: 4px 4px 0;
}

.turn {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #111;
  border: 2px solid #444;
  box-shadow: inset -2px -2px 4px rgba(255, 255, 255, 0.25);
}

.turn.white {
  background: #f4f1ea;
  border-color: #bbb;
  box-shadow: inset -2px -2px 4px rgba(0, 0, 0, 0.15);
}

.stage {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

#canvas {
  display: block;
  width: 100%;
  height: 100%;
  cursor: pointer;
}