html, body { margin: 0; height: 100%; background: #000; color: #bbb; font: 14px/1.4 system-ui, sans-serif; }
body { display: flex; flex-direction: column; align-items: center; justify-content: center; }
#screen { image-rendering: pixelated; image-rendering: crisp-edges; }
#drop { border: 2px dashed #777; padding: 3em 2em; max-width: 30em; text-align: center; cursor: pointer; }
#drop.over { border-color: #fff; color: #fff; }
#msg { color: #f77; min-height: 1.4em; margin: .3em; }
#help { max-width: 52em; font-size: 12px; color: #888; text-align: center; }
#help p { margin: .3em 0; }
#help b { color: #aaa; }