new MutationObserver(() => currentChallenge?.grid?.forEach((r, i) => r.forEach((c, j) => {
    if (c.isMine) document.querySelectorAll('#game-grid .cell')[i * currentChallenge.gridSize + j].style.boxShadow = 'inset 0 0 0 3px red'
}))).observe(document.querySelector('#game-grid'), {
    childList: true,
    subtree: true
}) || currentChallenge.grid.forEach((r, i) => r.forEach((c, j) => {
    if (c.isMine) document.querySelectorAll('#game-grid .cell')[i * currentChallenge.gridSize + j].style.boxShadow = 'inset 0 0 0 3px red'
}))