body {
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    margin: 0;
    background: linear-gradient(to bottom, #89CFF0, #003366);
    color: white;
}

h1 {
    margin-bottom: 20px;
}

.controls-container {
    margin-bottom: 30px;
}

.grid {
    display: grid;
    gap: 10px;
    margin-bottom: 20px;
}

.cell {
    width: 50px;
    height: 50px;
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2em;
    border: 2px solid #ccc;
    cursor: pointer;
    transition: background-color 0.3s;
}

.cell.on {
    background-color: red;
}

.cell.off {
    background-color: gray;
}

.cell.x {
    background-color: black;
    cursor: not-allowed;
}

.controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.row {
    display: flex;
    gap: 10px;
}

button {
    padding: 10px 20px;
    font-size: 1em;
    background-color: #00509E;
    border: none;
    border-radius: 5px;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #003F7D;
}

#solution {
    text-align: center;
    margin-top: 20px;
}