:root{--ink:#173c3f;--teal:#1a6668;--teal2:#dff4ee;--cream:#fbf7ec;--paper:#fffef9;--coral:#ef765f;--yellow:#f3c861;--line:#d8e4dc;--muted:#627477;--shadow:0 18px 45px rgba(23,60,63,.1);--radius:24px}*{box-sizing:border-box}html{font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;background:var(--cream);color:var(--ink)}body{margin:0;min-height:100vh;background:radial-gradient(circle at 90% 10%,#dff4ee 0,transparent 28%),var(--cream)}a{color:inherit;text-decoration:none}button,input,select{font:inherit}.topbar{max-width:1180px;margin:auto;padding:24px 28px;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:10px;font-size:1.25rem;font-weight:850}.brand-mark{display:grid;place-items:center;width:38px;height:38px;border-radius:12px;background:var(--ink);color:white;transform:rotate(-4deg)}nav{display:flex;gap:24px;align-items:center;font-weight:700;font-size:.94rem}nav 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strong{font-size:1.35rem}.topic-tabs{display:flex;gap:8px;overflow:auto;margin:0 0 18px}.topic-tabs button{border:1px solid var(--line);background:var(--paper);padding:10px 15px;border-radius:99px;font-weight:750;white-space:nowrap;cursor:pointer}.topic-tabs button.active{background:var(--ink);color:#fff}.question-card{position:relative;background:var(--paper);border:1px solid var(--line);border-radius:32px;padding:40px;box-shadow:var(--shadow);text-align:center;overflow:hidden}.progress{position:absolute;top:0;left:0;right:0;height:7px;background:#edf1ea}.progress span{display:block;width:100%;height:100%;background:var(--coral);transition:width 1s linear}.timer{position:absolute;right:22px;top:24px}.question{font-size:clamp(2.7rem,8vw,5.8rem);font-weight:900;color:var(--ink);margin:75px 0 35px;letter-spacing:-.05em}.question-card form{display:flex;gap:10px;max-width:500px;margin:auto}.question-card input,.stack input,.stack select{width:100%;border:2px solid 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