:root{color-scheme:light;--ink:#173b44;--accent:#176975;--line:#cddde1;--muted:#576d73;--pale:#edf6f6}*{box-sizing:border-box}body{margin:0;background:#f5f8f8;color:var(--ink);font-family:"Malgun Gothic",system-ui,sans-serif;line-height:1.7}button,a,summary{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer;border:1px solid #9ab8c0;border-radius:9px;background:white;color:var(--ink);padding:10px 16px}button:disabled{cursor:default;opacity:.45}button:hover:not(:disabled){background:var(--pale)}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #bd7815;outline-offset:3px}a{color:#145d9b;overflow-wrap:anywhere}.top{max-width:1080px;margin:auto;padding:30px 24px 16px;display:flex;justify-content:space-between;gap:16px;align-items:start}.top h1{font-size:30px;line-height:1.3;margin:0 0 10px}.top p{margin:0}.eyebrow,.kicker{font-size:14px;color:var(--accent);font-weight:700;letter-spacing:.02em}.review-tag{white-space:nowrap;border:1px solid var(--line);padding:4px 12px;border-radius:20px;font-size:13px}main{max-width:1032px;margin:auto;padding:0 24px 36px}.setup{padding:18px 0}.modes{display:flex;gap:8px;flex-wrap:wrap}.modes [aria-pressed=true],.primary{background:var(--ink);color:white;border-color:var(--ink)}.modes [aria-pressed=true]:hover,.primary:hover:not(:disabled){background:#255b67}.subtle,.page-note{font-size:14px;color:var(--muted)}.subtle{margin:12px 0}.session{display:flex;justify-content:space-between;align-items:center;gap:10px;font-size:14px}.plain{padding:5px 10px;background:transparent;font-size:14px}#outline{margin:0 0 16px;border:1px solid var(--line);border-radius:10px;background:white}summary{cursor:pointer;padding:12px 16px}#card-list{padding:8px 14px 16px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:7px}#card-list button{font-size:13px;text-align:left;padding:8px 10px;overflow-wrap:anywhere}#card-list [aria-current=true]{border:2px solid var(--accent);background:var(--pale)}.card{background:white;border:1px solid var(--line);border-radius:18px;padding:28px;box-shadow:0 8px 28px #173b4408}.card h2{font-size:26px;line-height:1.45;margin:6px 0 18px;overflow-wrap:anywhere}.question{font-size:21px;line-height:1.7;margin:0 0 22px}.reveal{min-height:48px}.answer{border-top:1px solid var(--line);margin-top:24px;padding-top:22px}.answer h3{font-size:15px;color:var(--accent);margin:0 0 8px}.answer-text{font-size:21px;line-height:1.85;margin:0 0 18px;word-break:keep-all;overflow-wrap:anywhere}.reason{margin:16px 0}.condition{background:#f8f5ed;border-left:4px solid #c8a568;padding:12px 15px;font-size:15px}.table-wrap{overflow:auto;max-width:100%;margin:18px 0}table{border-collapse:collapse;width:100%;font-size:16px}th,td{padding:10px 12px;border:1px solid var(--line);text-align:left;vertical-align:top;min-width:100px}th{background:var(--pale)}.card-actions,.navigation,.links{display:flex;gap:10px;flex-wrap:wrap}.card-actions{margin-top:24px}.navigation{justify-content:space-between;padding-top:22px;border-top:1px solid var(--line);margin-top:24px}.links{margin:20px 0 12px}.links button{font-size:14px;padding:8px 12px}.status-chip{font-size:13px;padding:3px 9px;border-radius:20px;background:#e6f1ee}.photo{margin:18px 0}.photo img{display:block;width:100%;max-height:420px;object-fit:contain;background:white;border:1px solid var(--line)}figcaption{font-size:13px;color:var(--muted);margin-top:7px}.visual{border:1px solid var(--line);border-radius:10px;margin:18px 0;overflow:hidden}.visual iframe{width:100%;border:0;display:block;min-height:200px;background:white}.custom-visual{display:block;width:100%;max-height:360px}.source-list{font-size:13px;overflow-wrap:anywhere}.page-note{margin:24px 0 0}.empty{padding:38px;text-align:center;background:white;border:1px solid var(--line);border-radius:14px}dialog{width:min(1100px,94vw);max-height:92vh;border:1px solid #8ba8b0;border-radius:14px;padding:0;color:var(--ink);overscroll-behavior:contain}dialog::backdrop{background:#102b36a8}.dialog-top{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:12px 20px;background:#eef5f5;position:sticky;top:0;z-index:2;border-bottom:1px solid var(--line)}.dialog-top p{margin:0;font-size:13px}.dialog-top button{font-size:14px;padding:8px 12px}#lesson-host{padding:26px;overflow-wrap:anywhere}#lesson-host h2{font-size:26px;margin:0 0 14px}#lesson-host h3{font-size:20px;margin:26px 0 10px}#lesson-host .source-section{scroll-margin-top:100px;padding:6px 0;border-bottom:1px solid #e2eaea}#lesson-host .target-section{border-left:4px solid var(--accent);padding-left:16px;background:#f4fafa}.quiz{border-top:1px solid var(--line);margin:22px 0;padding-top:14px}.quiz h4{font-size:18px}.quiz-options{display:grid;gap:8px}.quiz-options button{text-align:left}.quiz-options [aria-pressed=true]{border:2px solid var(--accent);background:var(--pale)}.feedback{border-left:4px solid var(--accent);background:var(--pale);padding:12px 16px;margin-top:14px}.feedback li{margin-bottom:8px}.lesson-switch{display:flex;gap:8px;flex-wrap:wrap;margin:18px 0}@media(max-width:600px){.top{padding:22px 14px 12px}.top h1{font-size:25px}.review-tag{font-size:11px;padding:3px 7px}main{padding:0 12px 24px}.card{padding:20px 16px;border-radius:12px}.card h2{font-size:23px}.question,.answer-text{font-size:19px}.modes button{font-size:14px;padding:9px 11px}#card-list{grid-template-columns:1fr 1fr}.session{align-items:start}.card-actions button{flex:1;padding:10px 8px}.dialog-top{padding:10px;align-items:start}#lesson-host{padding:18px 14px}.top>div{min-width:0}th,td{font-size:14px;padding:8px}.photo img{max-height:320px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}