*, *:before, *:after { box-sizing: border-box; position: relative; } body, html { height: 100%; width: 100%; margin: 0; padding: 0; background: black; } canvas { display: block; width: 100%; height: 100%; } .instructions { position: absolute; top:30%; left: 50%; margin-left:-8%; padding: 0.5em; background: rgba(0, 0, 0, 0.3); color: #FFF; font-size: 30px; font-family: monospace; }