body {
    font-family: Arial, sans-serif;
    background: #e6f2e6;
    margin: 0;
    padding: 20px;
}
#app {
    max-width: 500px;
    margin: auto;
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}