body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #f4f4f9;
    margin: 0;
    padding: 20px;
}
#app {
    max-width: 600px;
    margin: auto;
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 0 10px #aaa;
}
button {
    padding: 10px 20px;
    margin: 10px;
    font-size: 1em;
    cursor: pointer;
}
#options button {
    display: block;
    margin: 10px auto;
    width: 80%;
}
#feedback {
    font-weight: bold;
    margin-top: 20px;
}