body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f0f0;
}

#app {
    text-align: center;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

button {
    padding: 10px 20px;
    font-size: 16px;
    margin: 5px;
    cursor: pointer;
    border: none;
    background-color: #4CAF50;
    color: white;
    border-radius: 5px;
}

button:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
}

.options {
    margin-top: 20px;
}