.checkers-board {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 0;
  width: min(100%, 640px);
  margin: 0 auto;
  border: 0.5rem solid #2d3748;
  border-radius: var(--border-radius);
  touch-action: manipulation;
  user-select: none;
}

.checkers-cell {
  aspect-ratio: 1;
  min-width: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: clamp(1.8rem, 4vw, 3rem);
  position: relative;
  border: 0;
  padding: 0;
}

.checkers-cell.light {
  background-color: #edf2f7;
}

.checkers-cell.dark {
  background-color: #4a5568;
  cursor: pointer;
}

.checkers-cell.valid-move { box-shadow: inset 0 0 0 4px rgba(127, 186, 133, .9); }

.checkers-cell:focus-visible {
  z-index: 1;
  outline: 3px solid var(--accent);
  outline-offset: -3px;
}

.piece {
  width: 80%;
  height: 80%;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: inset 0 -3px 5px rgba(0,0,0,0.4), 0 2px 5px rgba(0,0,0,0.3);
  transition: all 0.2s ease;
}

.piece.red {
  background-color: #e53e3e;
}

.piece.white {
  background-color: #edf2f7;
}

.piece.king::after {
  content: '👑';
  font-size: clamp(1.4rem, 3vw, 2.5rem);
}

.piece.selected {
  transform: scale(1.15);
  box-shadow: 0 0 0 3px var(--primary), inset 0 -3px 5px rgba(0,0,0,0.4);
}

.valid-move::before {
  content: '';
  position: absolute;
  width: 25%;
  height: 25%;
  background-color: rgba(16, 185, 129, 0.7);
  border-radius: 50%;
}

.highlight-capture::after {
  content: '💥';
  position: absolute;
  color: #f56565;
  font-size: clamp(1rem, 2vw, 1.4rem);
  z-index: 2;
  animation: bounce 0.8s infinite alternate;
}

@keyframes bounce {
  from { transform: translateY(-3px); }
  to { transform: translateY(3px); }
}