#board {
    display: grid;
    grid-template-columns: repeat(8, 60px);
    grid-template-rows: repeat(8, 60px);
    gap: 3px;
    background: white;
    padding: 3px;
    border: 4px solid white;
    border-radius: 8px;
}
.cell {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    font-weight: bold;
    color: white;
    border-radius: 4px;
    transition: all 0.3s ease;
}
.cell-0 { background: #d3d3d3; }   /* 0 - Gray */
.cell-1 { background: #3498db; } /* 1 - Blue */
.cell-2 { background: #2ecc71; } /* 2 - Green */
.cell-3 { background: #f1c40f; } /* 3 - Yellow */
.cell-4 { background: #e74c3c; } /* 4 - Red */