:root {
  --bg: #0f1220;
  --card: #1a1e30;
  --card-2: #222741;
  --border: #2f3554;
  --text: #e8eaf6;
  --muted: #9aa0c3;
  --accent: #6c8cff;
  --accent-strong: #4a6cf7;
}

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

body {
  font-family: "Segoe UI", "Microsoft JhengHei", "Noto Sans TC", system-ui, sans-serif;
  background: radial-gradient(1200px 600px at 70% -10%, #232a4d 0%, var(--bg) 55%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 16px 40px;
}

header { text-align: center; margin-bottom: 20px; }
header h1 { font-size: 2rem; letter-spacing: 4px; }
.subtitle { color: var(--muted); margin-top: 6px; font-size: .95rem; }

main {
  width: 100%;
  max-width: 640px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px;
  box-shadow: 0 8px 24px rgba(0,0,0,.35);
}

.mode-row { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.pill {
  padding: 8px 14px; border-radius: 999px;
  background: var(--card-2); border: 1px solid var(--border);
  color: var(--text); font-size: .92rem; cursor: pointer;
  font-family: inherit;
}
.pill:hover { border-color: var(--accent); }
.pill.active { background: var(--accent-strong); border-color: var(--accent-strong); color: #fff; font-weight: 600; }

.status-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.chip { width: 16px; height: 16px; border-radius: 50%; background: #555; flex: none; box-shadow: 0 0 8px rgba(255,255,255,.15); }
#turnText { font-weight: 600; }
.spacer { flex: 1; }
.move-count { color: var(--muted); font-size: .85rem; font-variant-numeric: tabular-nums; }

button {
  font-family: inherit; cursor: pointer;
  border-radius: 10px; border: 1px solid var(--border);
  background: var(--card-2); color: var(--text);
  padding: 9px 16px; font-size: .92rem;
  transition: filter .15s ease;
}
button:hover { filter: brightness(1.18); }
.primary {
  background: linear-gradient(135deg, var(--accent-strong), var(--accent));
  border: none; color: #fff; font-weight: 600;
}

.home-row { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 12px; }
.home-count { display: inline-flex; align-items: center; gap: 6px; font-size: .88rem; color: var(--text); }
.home-count i { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }

.board-card { padding: 10px; display: flex; justify-content: center; }
#board { width: 100%; max-width: 560px; height: auto; display: block; touch-action: manipulation; }

.cell polygon { fill: #262b47; stroke: #333a5e; stroke-width: .05; transition: fill .15s ease; cursor: pointer; }
.cell.sel polygon { fill: #45508a; stroke: #ffffff; stroke-width: .09; }
.cell.hl-step polygon { fill: #33406e; stroke: #aebcf5; stroke-width: .08; }
.cell.hl-jump polygon { fill: #3d4079; stroke: #fbbf24; stroke-width: .09; animation: pulseHl 1s infinite alternate; }
.cell.lf polygon { fill: #2c3152; }
.cell.lt polygon { fill: #39406b; }
@keyframes pulseHl { from { stroke-opacity: .55; } to { stroke-opacity: 1; } }

.piece { pointer-events: none; transition: transform .3s cubic-bezier(.3,.9,.4,1); filter: drop-shadow(0 .08px .12px rgba(0,0,0,.6)); }
.piece circle { stroke: rgba(255,255,255,.5); stroke-width: .05; }

.rules-card details summary { cursor: pointer; color: var(--accent); font-size: .95rem; }
.rules-card ol { margin: 12px 0 4px 20px; line-height: 1.8; font-size: .9rem; color: #cfd4f2; }

.overlay {
  position: fixed; inset: 0; z-index: 50;
  background: rgba(8,10,22,.72); backdrop-filter: blur(3px);
  display: flex; align-items: center; justify-content: center;
}
.overlay.hidden { display: none; }
.overlay-box {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 18px; padding: 34px 44px; text-align: center;
  box-shadow: 0 16px 48px rgba(0,0,0,.6);
}
.overlay-box h2 { font-size: 1.7rem; margin-bottom: 10px; }
.overlay-box p { color: var(--muted); margin-bottom: 22px; }

#toast {
  position: fixed; left: 50%; bottom: 30px; transform: translateX(-50%) translateY(20px);
  background: #303658; color: #fff; padding: 10px 20px; border-radius: 999px;
  font-size: .9rem; opacity: 0; pointer-events: none; transition: all .25s ease; z-index: 60;
  border: 1px solid var(--border);
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

footer { margin-top: 26px; color: var(--muted); font-size: .78rem; }