body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    margin: 0;
    padding: 20px;
    text-align: center;
    background-color: #f4f4f4;
}

#app {
    max-width: 600px;
    margin: 0 auto;
    background-color: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.ios-guide {
    background-color: #f0f0f0;
    padding: 15px;
    margin-top: 20px;
    border-radius: 8px;
}

#installBtn {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
}