/* assets/css/board.css —— 棋盘 SVG 五层样式与动画 */

.board {
  width: 100%;
  max-width: 620px;
  margin: 0 auto;
  user-select: none;
  -webkit-user-select: none;
}

.board__caption {
  min-height: 20px;
  margin-bottom: 6px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 1px;
}

.board__svg {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  border-radius: 18px;
  box-shadow: var(--board-shadow);
  touch-action: manipulation;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
  cursor: pointer;
  background: var(--wood);
}

.board__wood { fill: var(--wood); }

.board__grid {
  stroke: var(--board-grid);
  stroke-width: 2.2;
  stroke-linecap: round;
  opacity: 0.72;
}

.board__star { fill: var(--board-star); opacity: 0.85; }

/* 真实棋盘粗边：随角旋转（lb 左+下、lt 左+上、rt 右+上、rb 右+下） */
.board__edge {
  stroke: var(--board-grid);
  stroke-width: 9;
  stroke-linecap: round;
  opacity: 0.95;
}

.board__coord {
  fill: var(--board-coord);
  font-size: 19px;
  font-weight: 600;
}

.board__stone { filter: drop-shadow(0 2px 2px rgba(40, 26, 8, 0.35)); }
.board__stone--black { fill: var(--stone-black); stroke: var(--stone-black); stroke-width: 1.5; }
.board__stone--white { fill: var(--stone-white); stroke: var(--stone-white-line); stroke-width: 1.5; }

.board__number { font-size: 25px; font-weight: 700; }
.board__number--black { fill: var(--stone-black-ink); }
.board__number--white { fill: var(--stone-white-ink); }

.board__last-move {
  fill: none;
  stroke: var(--board-last);
  stroke-width: 4;
  opacity: 0.9;
  pointer-events: none;
}

.board__wrong {
  fill: var(--board-wrong-fill);
  stroke: var(--danger);
  stroke-width: 4;
  pointer-events: none;
  animation: wrong-flash 0.5s ease-out;
}

.board__hint-region {
  fill: var(--board-hint-fill);
  stroke: var(--accent);
  stroke-width: 4;
  stroke-dasharray: 12 8;
  pointer-events: none;
  animation: hint-fade 0.9s ease-out;
}

.board__hint-candidate {
  fill: var(--board-hint-fill);
  stroke: var(--accent);
  stroke-width: 4;
  stroke-dasharray: 10 7;
  pointer-events: none;
  animation: hint-fade 0.9s ease-out;
}

.board__hint-precise {
  fill: var(--board-hint-fill-strong);
  stroke: var(--board-hint-line);
  stroke-width: 6;
  pointer-events: none;
  animation: hint-pulse 1.1s ease-in-out infinite;
}

.board--disabled .board__svg { cursor: default; filter: saturate(0.85); }

/* 触摸落点反馈：手指抬起后短暂显示，确认落点用 */
.board__touch {
  fill: var(--accent-ring-soft);
  stroke: var(--accent);
  stroke-width: 3;
  pointer-events: none;
  transform-box: fill-box;
  transform-origin: center;
  animation: touch-tap 0.34s ease-out forwards;
}
@keyframes touch-tap {
  from { opacity: 0.95; transform: scale(0.6); }
  to { opacity: 0; transform: scale(1.25); }
}

@keyframes wrong-flash {
  0% { opacity: 0.95; transform: scale(1.15); }
  100% { opacity: 0; transform: scale(1); }
}

@keyframes hint-fade {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes hint-pulse {
  0%, 100% { opacity: 0.55; }
  50% { opacity: 1; }
}

/* transform 动画以交叉点为原点更自然 */
.board__wrong { transform-box: fill-box; transform-origin: center; }