:root{--bg:#fbfaf7;--fg:#1d1d1f;--muted:#6b6b6b;--accent:#3b5bdb;--bad:#c92a2a;--good:#2b8a3e;--on-good:#fff;--line:#e3e1db;--watermark:.07;font-family:system-ui,sans-serif}@media (prefers-color-scheme:dark){:root{--bg:#16171a;--fg:#ececec;--muted:#9a9a9a;--accent:#8ca2ff;--bad:#ff8787;--good:#69db7c;--on-good:#0b2912;--line:#2c2e33;--watermark:.16}}body{background:var(--bg);color:var(--fg);margin:0}#app{max-width:720px;margin:0 auto;padding:16px}.visually-hidden{clip:rect(0 0 0 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}body:before{content:"∴";color:var(--accent);opacity:var(--watermark);z-index:-1;pointer-events:none;place-items:center;font-family:Georgia,Times New Roman,serif;font-size:min(80vw,28rem);line-height:1;display:grid;position:fixed;inset:0}button.submit{background:var(--good);border-color:var(--good);color:var(--on-good)}h1{margin:0 0 8px;font-size:1.2rem}.controls,.credits,.rules,.actions,.choices{flex-wrap:wrap;align-items:center;gap:6px;margin:8px 0;display:flex}button,select{font:inherit;border:1px solid var(--line);color:inherit;background:0 0;border-radius:8px;min-width:40px;min-height:40px;padding:8px 10px}button.on,button.primary,.num.selected{background:var(--accent);color:#fff;border-color:var(--accent)}button:disabled{opacity:.4}.proof{margin:8px 0;padding:0;font-family:ui-monospace,Menlo,Consolas,monospace;list-style:none}.line{padding:4px 0 4px calc(var(--depth) * 1.5em);border-bottom:1px solid var(--line);flex-wrap:wrap;align-items:baseline;gap:10px;display:flex}.line.inblock{border-left:2px solid var(--accent)}.line .formula{flex:1}.just,.therefore,.muted{color:var(--muted)}#formula{box-sizing:border-box;border:1px solid var(--line);width:100%;color:inherit;background:0 0;border-radius:8px;padding:10px;font:1.1rem ui-monospace,Menlo,Consolas,monospace}#preview{min-height:1.5em;margin:6px 0;font-family:ui-monospace,Menlo,Consolas,monospace}#preview mark{background:var(--bad);color:#fff}#preview .why,#message.error{color:var(--bad)}#message.success{color:var(--good)}textarea{box-sizing:border-box;width:100%;font:inherit;color:inherit;border:1px solid var(--line);background:0 0;border-radius:8px;margin:6px 0}.chip{border:1px solid var(--line);color:var(--muted);border-radius:8px;padding:8px 10px}.pad-row{flex-wrap:wrap;align-items:center;gap:6px;display:flex}.pad{flex-direction:column;gap:6px;margin:8px 0;display:flex}.pad button[aria-label] .sym,.pad button[aria-label] .word{line-height:1.1;display:block}.pad button[aria-label] .word{color:var(--muted);font-size:.65rem}.record{margin:8px 0}.record .card{border:1px solid var(--line);background:var(--bg);border-radius:16px;padding:20px 16px 14px;position:relative}.record .brand{color:var(--accent);margin:0;font-family:Georgia,Times New Roman,serif;font-size:2rem}.record .who{color:var(--muted);overflow-wrap:anywhere;margin:4px 0 12px}.record .section{border-top:1px solid var(--line);padding:10px 0}.record h2{text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0 0 6px;font-size:.75rem}.record .stat{margin:2px 0}.record .stat .n{font:700 1.6rem Georgia,Times New Roman,serif}.record .sub{color:var(--muted);font-size:.85rem}.record .best{border:1px solid var(--accent);border-radius:12px;margin-top:8px;padding:10px 12px}.record .best .n{font:700 1.3rem Georgia,Times New Roman,serif;display:block}.record .best.empty{color:var(--muted);border-style:dashed;border-color:var(--line)}.record .card-foot{border-top:1px solid var(--line);color:var(--muted);justify-content:space-between;align-items:center;gap:8px;padding-top:10px;font-size:.85rem;display:flex}.record .name-field{margin-top:14px;display:block}.record .name-field input{box-sizing:border-box;width:100%;font:inherit;border:1px solid var(--line);color:inherit;background:0 0;border-radius:8px;margin-top:4px;padding:10px;display:block}