body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

h1 {
    color: #2c3e50;
    text-align: center;
}

.bingo-grid {
    margin: 20px 0;
}

.bingo-row {
    display: flex;
    justify-content: center;
}

.bingo-cell {
    width: 150px;
    height: 100px;
    border: 2px solid #3498db;
    margin: 2px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 5px;
    cursor: pointer;
    background-color: #ecf0f1;
    transition: background-color 0.3s;
}

.bingo-cell:hover {
    background-color: #d6eaf8;
}

.bingo-cell.selected {
    background-color: #2ecc71;
    color: white;
    font-weight: bold;
}

button {
    display: block;
    margin: 20px auto;
    padding: 10px 20px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
}

button:hover {
    background-color: #2980b9;
}