html,body       { width: 100%; height: 100%; margin: 0; padding: 0; overflow: hidden; }
*:focus         { outline: none; }

#content        { position: absolute; top: 0; left: 0; width: 100%; height: 100%; overflow: auto; z-index: 0; }
#sky            { position: absolute; top: 0; left: 0; width: 100%; height: 100%; overflow: hidden; z-index: -1; }