:root{color-scheme:light;--ink:#16394c;--muted:#526575;--line:#d5e1e7;--accent:#126b7a;--paper:#fff;--bg:#f0f5f8;font-family:-apple-system,BlinkMacSystemFont,"Hiragino Kaku Gothic ProN","Yu Gothic",sans-serif;color:var(--ink);background:var(--bg);font-size:16px}*{box-sizing:border-box}body{margin:0}header{background:var(--ink);color:#fff;padding:24px max(20px,calc((100% - 940px)/2));border-bottom:4px solid #46b8c2}.brand{font-size:1.4rem;font-weight:750;letter-spacing:.04em}.brand span{font-size:.9rem;border-left:1px solid #7fabbc;margin-left:12px;padding-left:12px}header p{font-size:.875rem;color:#c8dce5;margin:8px 0 0}main{max-width:940px;margin:auto;padding:32px 20px 20px}h1{font-size:1.65rem;margin:5px 0 22px;line-height:1.5}.heading{display:flex;justify-content:space-between;align-items:center;gap:14px}.eyebrow{font-size:.75rem;font-weight:750;letter-spacing:.15em;color:var(--accent);margin:0}.review-total{text-align:center;min-width:76px}.review-total strong{display:block;font-size:1.75rem}.review-total span{font-size:.8rem;color:var(--muted)}fieldset{min-width:0;background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:18px;margin:0 0 22px}legend{font-size:1.06rem;font-weight:700;padding:0 8px}legend b{color:var(--accent);font-size:.8rem;margin-right:8px}.hint{font-size:.875rem;line-height:1.7;color:var(--muted);margin:0 0 12px}.bulk{display:flex;gap:8px;margin-bottom:12px}button{font:inherit;cursor:pointer;touch-action:manipulation;min-height:46px;padding:10px 16px;border:1px solid var(--line);border-radius:9px;background:white;color:var(--ink);font-weight:600}button:hover{background:#eaf4f6}button:disabled{opacity:.45;cursor:default}.bulk button{font-size:.875rem}.choices{display:grid;gap:8px;grid-template-columns:repeat(2,minmax(0,1fr))}.choices.inline{display:flex;flex-wrap:wrap}.choice{display:flex;align-items:center;gap:10px;min-height:48px;padding:10px 12px;background:#f6f9fb;border:1px solid transparent;border-radius:8px;font-size:.94rem;line-height:1.6;cursor:pointer;overflow-wrap:anywhere}.choice:has(input:checked){background:#e6f3f5;border-color:#9bcad0}.choice small{color:var(--muted);margin-left:auto;white-space:nowrap}input[type=checkbox],input[type=radio]{width:20px;height:20px;accent-color:var(--accent);flex-shrink:0;margin:0}input:focus-visible,button:focus-visible{outline:3px solid #da8a19;outline-offset:3px}.section-heading{grid-column:1/-1;font-size:.875rem;margin:12px 0 0;font-weight:700}.pair{display:grid;grid-template-columns:1fr 1fr;gap:18px}.pair fieldset{margin-bottom:16px}.number{display:flex;align-items:center;gap:12px;margin-top:12px}.number input{width:130px;max-width:80%;font:inherit;font-size:1.4rem;border:1px solid #a9bdc9;border-radius:8px;padding:12px;background:white;color:var(--ink)}.review-box{padding:16px;background:#e6edf3;border-radius:12px}.review-box .choice{background:transparent;padding:0}.review-box p{margin:8px 0 0}.start-bar{position:sticky;bottom:0;display:flex;justify-content:space-between;align-items:center;gap:16px;padding:18px 0 max(18px,env(safe-area-inset-bottom));background:var(--bg);border-top:1px solid var(--line);margin-top:22px}.start-bar strong{font-size:1.6rem}.start-bar p{font-size:.8rem;color:var(--muted);margin:3px 0}.primary{background:var(--accent);color:white;border-color:var(--accent);padding:14px 24px}.primary:hover{background:#0c5260}.footnote,footer{font-size:.8rem;color:var(--muted);line-height:1.8}footer{text-align:center;padding:16px 20px 30px}.study-top{display:flex;justify-content:space-between;align-items:center;gap:14px;font-size:.9rem}progress{width:100%;height:7px;accent-color:var(--accent);margin:18px 0}.meta{font-size:.875rem;line-height:1.9;color:var(--muted);margin-bottom:14px}.question-card{background:white;border:1px solid var(--line);border-radius:16px;padding:30px}.question-card h1{font-size:1rem;color:var(--muted);margin:0 0 16px}#prompt,#explanation{white-space:pre-wrap;overflow-wrap:anywhere;line-height:1.95}#prompt{font-size:1.125rem;margin:0 0 28px}.answer-buttons{display:grid;grid-template-columns:1fr 1fr;gap:16px}.answer-buttons button{font-size:2.5rem;min-height:104px;border:2px solid #93b7c5;color:var(--accent)}.answer-buttons span{display:block;font-size:.875rem}.explanation{padding-top:10px;border-top:1px solid var(--line);margin-top:22px}.explanation h3{font-size:1rem}#verdict{font-size:1.4rem}.correct{color:#147046}.incorrect{color:#b33832}.wide{width:100%}.result-card{text-align:center;background:white;padding:40px 20px;border-radius:16px;border:1px solid var(--line)}.score{font-size:3rem;font-weight:750;color:var(--accent);margin:20px 0}.notice{background:#fff0d8;color:#694510;padding:16px;line-height:1.7;border-radius:8px}[hidden]{display:none!important}@media(max-width:600px){main{padding:24px 14px 14px}header{padding:20px 16px}.choices{grid-template-columns:1fr}.pair{grid-template-columns:1fr;gap:0}fieldset{padding:14px;margin-bottom:20px}.question-card{padding:22px 18px}h1{font-size:1.4rem}.primary{padding:14px 18px}.start-bar{gap:10px}.brand{font-size:1.2rem}}@media(prefers-reduced-motion:no-preference){button{transition:background .15s}}

.records-link{text-align:right;margin-bottom:20px}.button-link{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:10px 16px;border:1px solid var(--line);border-radius:9px;background:#fff;color:var(--accent);font-size:.94rem;font-weight:650;text-decoration:none}.button-link:hover{background:#e6f3f5}.button-link:focus-visible{outline:3px solid #da8a19;outline-offset:3px}#records h1{margin-top:24px}#records h2{font-size:1.1rem;margin:26px 0 14px}.stat-card{background:white;border:1px solid var(--line);border-radius:12px;padding:20px}.stat-card h3{font-size:1rem;margin:0 0 20px;line-height:1.6}.stat-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:18px;margin:0}.stat-grid dt{font-size:.875rem;color:var(--muted)}.stat-grid dd{font-size:1.7rem;font-weight:750;margin:8px 0;color:var(--ink)}.stat-grid small{font-size:.8rem;color:var(--muted);line-height:1.7;display:block}.stat-card progress{margin:20px 0 0}.chapter-stats{display:grid;gap:14px}.metrics-note{font-size:.875rem;line-height:1.85;color:var(--muted);margin-top:28px}.metrics-note h2{color:var(--ink)}@media(max-width:600px){.stat-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:22px 12px}.stat-card{padding:18px}.stat-grid dd{font-size:1.55rem}}