:root{color-scheme:light;--ink:#172033;--muted:#667085;--line:#d9e2ef;--soft:#f5f8fc;--accent:#2457c5;--good:#177245;--bad:#b42318;--warn:#a15c07;--card:#fff}*{box-sizing:border-box}body{margin:0;background:#f7f9fc;color:var(--ink);font:17px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif}main{max-width:960px;margin:0 auto;padding:44px 22px 72px}header{margin-bottom:28px}h1{font-size:42px;line-height:1.05;margin:0 0 10px;letter-spacing:-.03em}h2{font-size:25px;margin:34px 0 12px;letter-spacing:-.015em}h3{font-size:19px;margin:0 0 8px}.deck{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:18px 0}.card,.quiz,.callout{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:18px;box-shadow:0 8px 26px rgba(16,24,40,.04)}.kicker{color:var(--accent);font-weight:800;text-transform:uppercase;letter-spacing:.08em;font-size:13px}.muted{color:var(--muted)}.big{font-size:30px;font-weight:850;letter-spacing:-.03em}.trap{border-left:5px solid var(--warn)}.ok{border-left:5px solid var(--good)}code{background:#eef3fb;padding:.12em .34em;border-radius:6px}.pill{display:inline-block;border:1px solid var(--line);border-radius:999px;padding:4px 9px;margin:3px;background:#fff;font-size:14px}.q{border-top:1px solid var(--line);padding:16px 0}.q:first-child{border-top:0;padding-top:0}button{font:inherit;border:1px solid var(--line);background:#fff;border-radius:12px;padding:10px 12px;margin:5px 6px 5px 0;cursor:pointer}button:hover{border-color:var(--accent)}button.correct{border-color:var(--good);background:#ecfdf3}button.wrong{border-color:var(--bad);background:#fff1f0}input[type=password],input[type=text]{font:inherit;border:1px solid var(--line);border-radius:12px;padding:10px 12px;max-width:360px;width:100%}.option-line{display:block;margin:8px 0;padding:8px 10px;border:1px solid var(--line);border-radius:12px;background:#fff}.option-line input{margin-right:8px}fieldset{border:0;margin:0;padding:0}.answer{display:none;margin-top:8px}.answer.show{display:block}.source{font-size:14px;color:var(--muted)}ul.tight li{margin:5px 0}@media print{body{background:white}main{padding:20px}.card,.quiz,.callout{box-shadow:none}button{display:none}.answer{display:block}}