:root{--bg:#fff;--surface:#fff;--sunk:#f3f5f8;--ink:#0f1b2d;--muted:#5a6676;--line:#e1e5eb;--accent:#1c4f9c;--accent-ink:#fff;--accent-soft:#e9f0fa;--ok:#17803d;--ok-soft:#e8f5ec;--bad:#b42318;--bad-soft:#fdecea;--warn:#8a5a00;--warn-soft:#fdf3dc;--f-display:"Instrument Sans",system-ui,-apple-system,"Segoe UI",sans-serif;--f-ui:"Instrument Sans",system-ui,-apple-system,"Segoe UI",sans-serif;--f-mono:"JetBrains Mono",ui-monospace,Menlo,Consolas,monospace;--r:10px;color-scheme:light}*{box-sizing:border-box}body,html{margin:0}body{background:var(--bg);color:var(--ink);font-family:var(--f-ui);font-size:15px;line-height:1.55}a{color:var(--accent)}button,input,select,textarea{font:inherit;color:inherit}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.wrap{max-width:960px;margin:0 auto;padding-left:16px;padding-right:16px}.narrow{max-width:720px}header.top{position:-webkit-sticky;position:sticky;top:0;z-index:5;background:var(--surface);border-bottom:1px solid var(--line)}.bar{gap:16px;padding-block:12px;flex-wrap:wrap}.bar,.brand{display:flex;align-items:center}.brand{gap:10px;font-weight:700;font-size:17px;color:var(--ink);text-decoration:none;line-height:1.15}.brand small{display:block;font-size:12px;font-weight:600;color:var(--accent);letter-spacing:.06em;text-transform:uppercase}.rx{width:30px;height:30px;border-radius:7px;background:var(--accent);color:var(--accent-ink);display:grid;place-items:center;font-family:var(--f-display);font-size:20px;line-height:1}nav.links{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto;align-items:center}nav.links a{padding:8px 10px;border-radius:7px;color:var(--muted);text-decoration:none;font-weight:600;font-size:14px}nav.links a.on,nav.links a:hover{color:var(--ink);background:var(--sunk)}main{padding-block:28px 72px}footer.site{border-top:1px solid var(--line);padding-block:24px;color:var(--muted);font-size:13px}footer.site .row{justify-content:space-between}h1,h2,h3{margin:0;text-wrap:balance}h1{font-size:46px;line-height:1.1;letter-spacing:-.025em}h1,h2{font-family:var(--f-display);font-weight:700}h2{font-size:28px;line-height:1.2;letter-spacing:-.015em}h3{font-size:16px;font-weight:700}p{margin:0}.lede{max-width:62ch;margin-top:8px;font-size:17px}.eyebrow,.lede{color:var(--muted)}.eyebrow{font-size:11px;font-weight:700;letter-spacing:.08em;text-transform:uppercase}.stack{flex-direction:column;gap:20px}.row,.stack{display:flex}.row{gap:10px;flex-wrap:wrap;align-items:center}.panel{border:1px solid var(--line);border-radius:var(--r);padding:20px}.btn,.panel{background:var(--surface)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:1px solid var(--line);padding:10px 18px;border-radius:8px;font-weight:600;cursor:pointer;font-size:14px;text-decoration:none;color:var(--ink)}.btn:hover{background:var(--sunk)}.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}.btn.primary:hover{filter:brightness(1.07)}.btn.ghost{border-color:transparent;background:none;color:var(--muted)}.btn.lg{padding:13px 22px;font-size:15px}.btn:disabled{opacity:.45;cursor:not-allowed}.chips{flex-wrap:wrap}.chip,.chips{display:flex;gap:8px}.chip{border:1px solid var(--line);background:var(--surface);border-radius:99px;padding:7px 14px;font-size:13px;font-weight:600;cursor:pointer;align-items:center}.chip[aria-pressed=true]{background:var(--accent-soft);border-color:var(--accent)}.chip .n{font-family:var(--f-mono);font-size:11px;color:var(--muted)}.field{display:flex;flex-direction:column;gap:6px}.field label{font-size:13px;font-weight:600}input[type=email],input[type=password],input[type=text]{background:var(--bg);border:1px solid var(--line);border-radius:8px;padding:10px 12px;width:100%;min-width:0}.mono{font-family:var(--f-mono);font-feature-settings:"tnum";font-variant-numeric:tabular-nums}.muted{color:var(--muted)}.small{font-size:13px}.grid{display:grid;grid-gap:16px;gap:16px;grid-template-columns:repeat(auto-fit,minmax(210px,1fr))}.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));grid-gap:12px;gap:12px}.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:14px 16px}.stat b{display:block;font-family:var(--f-mono);font-size:26px;font-weight:600;letter-spacing:-.02em;font-feature-settings:"tnum";font-variant-numeric:tabular-nums}.stat span{font-size:12px;color:var(--muted)}.notice{border-radius:8px;padding:12px 16px;background:var(--warn-soft);color:var(--ink);border:1px solid var(--line)}.notice.ok{background:var(--ok-soft)}.notice.bad{background:var(--bad-soft)}.note{font-size:13px;color:var(--muted);border-radius:8px;padding:10px 14px;max-width:72ch}.meter,.note{background:var(--sunk)}.meter{height:6px;overflow:hidden;margin-top:10px}.meter,.meter i{border-radius:99px}.meter i{display:block;height:100%;background:var(--accent);transition:width .25s}.tag{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:600;color:var(--muted)}.tag .area{background:var(--accent-soft);color:var(--ink);border-radius:5px;padding:2px 8px}.stem{font-size:19px;font-weight:500;line-height:1.5;margin:14px 0 18px;max-width:65ch}.opts{flex-direction:column;gap:8px}.opt,.opts{display:flex}.opt{gap:12px;align-items:flex-start;text-align:left;border:1px solid var(--line);background:var(--surface);border-radius:9px;padding:12px 14px;cursor:pointer;width:100%;font-size:15px}.opt:hover:not(:disabled){border-color:var(--accent)}.opt .L{flex:none;width:26px;height:26px;border-radius:6px;background:var(--sunk);display:grid;place-items:center;font-family:var(--f-mono);font-size:12px;font-weight:600}.opt .tx{min-width:0;padding-top:2px}.opt:disabled{cursor:default}.opt.correct{border-color:var(--ok);background:var(--ok-soft)}.opt.correct .L{background:var(--ok);color:var(--surface)}.opt.wrong{border-color:var(--bad);background:var(--bad-soft)}.opt.wrong .L{background:var(--bad);color:var(--surface)}.explain{margin-top:16px;border-left:3px solid var(--accent);background:var(--sunk);padding:12px 16px;border-radius:0 8px 8px 0;max-width:72ch}.verdict{font-weight:700;margin-bottom:4px}.verdict.ok{color:var(--ok)}.verdict.bad{color:var(--bad)}.kbd{font-family:var(--f-mono);font-size:11px;border:solid var(--line);border-width:1px 1px 2px;border-radius:4px;padding:0 5px;color:var(--muted)}.score-big{font-size:60px;line-height:1;font-weight:700;letter-spacing:-.02em}.arearows{display:flex;flex-direction:column;gap:14px}.arow{display:grid;grid-template-columns:minmax(0,1fr) auto;grid-gap:4px 12px;gap:4px 12px;align-items:baseline}.arow .track{grid-column:1/-1;height:10px;background:var(--sunk);border-radius:99px;overflow:hidden}.arow .track i{display:block;height:100%;border-radius:99px;background:var(--accent)}.arow .track i.low{background:var(--bad)}.arow .track i.mid{background:var(--warn)}.arow .lbl{font-weight:600;font-size:14px;min-width:0}.arow .val{font-family:var(--f-mono);font-size:13px}.pill{display:inline-block;font-size:11px;font-weight:700;border-radius:99px;padding:2px 8px}.pill.bad{background:var(--bad-soft);color:var(--bad)}.pill.ok{background:var(--ok-soft);color:var(--ok)}.pill.warn{background:var(--warn-soft);color:var(--warn)}.chart{width:100%;height:auto;display:block}.chart text{fill:var(--muted);font-family:var(--f-mono);font-size:11px}.tablewrap{overflow-x:auto}table{border-collapse:collapse;width:100%;font-size:14px}td,th{text-align:left;padding:9px 10px;border-bottom:1px solid var(--line);white-space:nowrap}th{font-size:12px;color:var(--muted);font-weight:600}td.num,th.num{text-align:right;font-family:var(--f-mono);font-feature-settings:"tnum";font-variant-numeric:tabular-nums}.qlist{display:flex;flex-direction:column;gap:10px}details.qi{background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}details.qi summary{cursor:pointer;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;list-style:none}details.qi summary::-webkit-details-marker{display:none}details.qi summary .s{min-width:0;flex:1 1}details.qi .body{padding:0 16px 16px}.ans{margin:8px 0;padding:0;list-style:none;display:flex;flex-direction:column;gap:4px}.ans li{padding:4px 8px;border-radius:6px}.ans li.k{background:var(--ok-soft);font-weight:600}.empty{text-align:center;padding:40px 20px;color:var(--muted);border:1px dashed var(--line);border-radius:var(--r)}.empty h3{color:var(--ink);margin-bottom:6px}.hero{padding-block:36px 12px;display:grid;grid-gap:32px;gap:32px;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);align-items:center}.hero .demo{box-shadow:0 12px 32px rgba(15,27,45,.08)}.plans{display:grid;grid-gap:16px;gap:16px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}.plan{display:flex;flex-direction:column;gap:12px}.plan.best{border-color:var(--accent);box-shadow:0 0 0 1px var(--accent)}.plan .price{font-size:40px;font-weight:700;line-height:1;letter-spacing:-.02em}.feat{display:flex;flex-direction:column;gap:6px}.feat b{font-size:15px}.faq details{border-bottom:1px solid var(--line);padding-block:14px}.faq summary{cursor:pointer;font-weight:600}.faq details p{margin-top:8px;color:var(--muted);max-width:70ch}.section{padding-block:40px}@media (max-width:760px){.hero{grid-template-columns:1fr}h1{font-size:36px}.stem{font-size:19px}}@media (prefers-reduced-motion:reduce){*{transition:none!important}}.explain p+p{margin-top:8px}.wrong{margin-top:12px;max-width:72ch}.wrong h4{margin:0 0 6px;font-size:13px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}.wrong ul{margin:0;padding:0;list-style:none;display:flex;flex-direction:column;gap:6px}.wrong li{display:grid;grid-template-columns:22px minmax(0,1fr);grid-gap:8px;gap:8px;font-size:14px}.wrong li b{font-family:var(--f-mono);font-size:12px;color:var(--bad)}.check{display:flex;gap:10px;align-items:flex-start;font-size:14px}.check input{margin-top:4px;width:16px;height:16px;accent-color:var(--accent)}.qfig{border:1px solid var(--line);border-radius:10px;padding:10px;margin:0 0 16px;background:#fff;overflow-x:auto}.qfig svg{display:block;width:100%;max-width:620px;height:auto;margin:0 auto}.ofig{display:block;margin-top:6px}.ofig svg{display:block;width:100%;max-width:240px;height:auto}.opts.figgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}