.kk-board {
  display: grid;
  gap: 3px;
  margin: 8px auto;
  width: max-content;
  background: #e7ecf3;
  padding: 5px;
  border-radius: 10px;
}
.kk-cell {
  width: 40px;
  height: 40px;
  background: #fff;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
  font-weight: 700;
  color: #2f6fd6;
  transition: background .12s, color .12s;
}
.kk-cell.on {
  background: #4d96ff;
  color: #fff;
}
.kk-w {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  font-weight: 700;
  color: #c0392b;
  font-size: 15px;
}
.kk-w.col { color: #c0392b; }
.kk-w.row { color: #16a085; }
.kk-corner { width: 40px; height: 40px; }