body 
{
    margin:0;
    background-color: black;
    color: white;
    height: 100vh;
}

main
{
    position: absolute;
    transform: translate(-50%,-50%);
    left: 50%;
    top: 50%;
    font-size: 1.5em;
    font-family: 'Courier New', Courier, monospace;
    text-align: center;
}

a {color: white;}

a.button
{
    background-color: navy;
    padding: 12px;
    border-radius: 8px;
    text-decoration: none;
    color: white;
}
a:hover.button
{
    background-color: powderblue;
    color: black;
    transition: background-color 2s, color 0.7s;
}
p {margin: 32px}

.errnum {font-size: 80%;}

@media screen and (max-width: 600px) 
{
    main 
    {
        position: static;
        transform: translate(0,0);
    }
}