body { background: #222222; color: #efefef; font-family: sans-serif; } .source { background: #444444; color: #efefef; min-height: 50vh; min-width: 50vw; font-size: 300%; } button { background: #444444; color: #efefef; font-size: 300%; margin-left: 10px; } pre { font-size: 300%; }