html {
    height: 100%;
}

html, body, #main-body, #main-content, #login {
    display: flex;
    flex: 1;
}

#login {
    align-items: center;
    justify-content: center;
}

    #login form {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
    }

    #login input {
        padding: .5rem;
        margin-bottom: 1rem;
        border-radius: 4px;
        width: 12rem;
    }

    #login button {
        width: 13rem;
    }

    #login .error-message {
        color: red;
        margin-top: 1rem;
    }