body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
}

.keyboard {
    display: grid;
    gap: 5px;
    background-color: #333;
    padding: 20px;
    border-radius: 10px;
}

.row {
    display: flex;
}

button {
    font-size: 16px;
    padding: 15px;
    margin: 2px;
    background-color: #fff;
    border: 1px solid #ccc;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:active, .active {
    background-color: #4CAF50;
    color: #fff;
}

.space {
    flex: 1;
}