:root{--fg: #000;--bg: #fff}body,html{margin:0;padding:0;width:100%;height:100%;overflow:hidden;background:var(--bg);font-family:Courier New,Courier,monospace;color:var(--fg);-webkit-user-select:none;user-select:none}canvas{display:block}#ui{position:absolute;top:0;left:0;width:100%;height:100%;pointer-events:none;padding:20px;box-sizing:border-box;display:flex;flex-direction:column;justify-content:space-between}.header{pointer-events:auto}.back-link{text-decoration:none;color:var(--fg);font-size:14px;opacity:.5;transition:opacity .2s}.back-link:hover{opacity:1}h1{font-size:24px;font-weight:400;margin:10px 0 0;letter-spacing:2px}.hud{position:absolute;top:20px;right:20px;text-align:right;font-size:14px;line-height:1.5}.controls{pointer-events:auto;font-size:12px;opacity:.7}.instruction{line-height:1.6}