body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: white;
    margin: 1em auto;
    width: 400px;
    padding: 0 2em 1em;
    border: 1px solid black;
    border-radius: 1em;
}
h1 {
    color: cornflowerblue;
}
input, button {
    margin: 0 0.5em 1em 0;
}
#error_message {
    color: red;
}