@keyframes popIn {
    0% { transform: scale(0); opacity: 0; }
    80% { transform: scale(1.1); opacity: 1; }
    100% { transform: scale(1); }
}

.cell:not(:empty) {
    animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}