main {
    display: flex;
    align-items: center;
    align-content: center;
    justify-content: center;

    height: calc(100vh - 2 * 3em);
    width: 100%;
}

@media only screen and (max-device-width: 800px) {
    main {
        flex-direction: column;
    }
}

main form {
    max-width: 600px;
    width: 100%;

    margin-left: 0.5em;
}

main form input {
    width: 100%;
}

main > div {
    margin-right: 0.5em;
}

footer {
    margin-top: 0.833em;
}