html
{
    font-family: monospace;
}

html, body, #banner
{
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

@keyframes delayed-fade-in
{
    0%   {visibility: hidden;  opacity: 0;}
    95%  {visibility: hidden;  opacity: 0;}
    100% {visibility: visible; opacity: 1;}
}

#banner
{
    font-family: sans-serif;
    background-color: #000a;
    animation-name: delayed-fade-in;
    animation-duration: 5s;
}

#accept
{
    display: none;
}

#accept:checked ~ #banner
{
    visibility: hidden;
    opacity: 0;
    transition: visibility .2s, opacity .2s;
}

label[for=accept]
{
    font-weight: bold;
    font-size: 200%;
    padding: .5em;
    color: #eee;
    background-color: #c00;
    opacity: 1;
    cursor: pointer;
    transition: color 0.1s, background-color .1s;
}

label[for=accept]:hover
{
    color: #fff;
    background-color: #f00;
}