html {
    color-scheme: light dark;
}
a {
    font-size: small;
    color: inherit;
}
form {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 1em;
}
form > * {
    margin: 0;
}
form :invalid {
    box-shadow: red 0 0 1em;
}