body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: white;
    padding: 10px 20px;
    text-align: center;
}

h1, h2 {
    margin: 10px 0;
}

button {
    display: block;
    width: 90%;
    padding: 10px;
    margin: 20px auto;
    background-color: #888;
    color: white;
    border: none;
    border-radius: 5px;
}

.error-message {
    color: red;
    text-align: center;
    margin-top: 10px;
}