body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    width: 90%;
    max-width: 400px;
}

/* 媒体查询 */
@media (max-width: 600px) {
    .container {
        width: 100%;
        margin: 10px;
    }

    form label, form input, form select, form button {
        width: 100%;
        margin-top: 10px;
    }

    form label {
        display: block;
    }
}