body 
{
    margin: 0;
}
#cc 
{
    width: 100vw;
    height: 100vh;
    display: block;
}
.container 
{
    position: relative;
}
#overlay
{
    position: absolute;
    left: 10px;
    top: 10px;
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    font-family: monospace;
    font-size: large;
    padding: 1em;
}