public/style.css

.board {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    grid-template-rows: repeat(3, 100px);
    gap: 5px;
    background-color: #34495e;
    padding: 10px;
    border-radius: 10px;
    width: fit-content;
    margin: 50px auto;
}

.cell {
    background-color: #ecf0f1;
    border-radius: 5px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 40px;
    font-family: Arial, sans-serif;
    cursor: pointer;
    transition: background-color 0.3s;
}

.cell:hover {
    background-color: #bdc3c7;
}

.x::before {
    content: "X";
    color: #e74c3c;
}

.o::before {
    content: "O";
    color: #3498db;
}

h1 {
    text-align: center;
    color: #2c3e50;
    font-family: Arial, sans-serif;
}

.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    background-color: #f5f6fa;
    min-height: 100vh;
    margin: 0;
}