@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@400;500;600;700&family=Noto+Serif:wght@400;500;600&display=swap');
:root{color-scheme:light;--bg:#f5f3ec;--paper:#fffefb;--ink:#243b34;--muted:#67736b;--line:#dfE3d9;--green:#235b48;--soft:#eaf2eb;--amber:#9c542e;--normal:#f2f2ec;--size:17px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:110px}body{margin:0;background:var(--bg);color:var(--ink);font:400 var(--size)/1.85 'Be Vietnam Pro','Segoe UI',sans-serif}body.dark{color-scheme:dark;--bg:#16231f;--paper:#1d2d27;--ink:#e1e9df;--muted:#b0bdb3;--line:#3a4b40;--green:#a4d6b4;--soft:#283e32;--amber:#e5b18c;--normal:#27352e}button,input{font:inherit}button,a,input{touch-action:manipulation}button,a{ -webkit-tap-highlight-color:transparent}button{cursor:pointer}a{color:var(--green)}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid var(--amber);outline-offset:4px}a{text-underline-offset:4px}.skip{position:fixed;top:-100px;left:16px;z-index:100;background:var(--paper);padding:8px 16px}.skip:focus{top:12px}.progress{position:fixed;top:0;left:0;width:0;height:3px;background:var(--green);z-index:60}.topbar{position:sticky;top:0;z-index:40;height:76px;display:flex;align-items:center;justify-content:space-between;padding:0 42px;background:var(--bg);border-bottom:1px solid var(--line);gap:14px}.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:var(--ink);font-weight:600;font-size:16px}.brand-icon{width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:var(--green);color:var(--paper);font-family:serif;font-size:22px}.top-label{font-size:12px;color:var(--muted);border-left:1px solid var(--line);margin-left:10px;padding-left:20px;letter-spacing:.04em}.tools{display:flex;align-items:center;gap:6px}.tool{border:1px solid var(--line);background:var(--paper);color:var(--ink);border-radius:8px;padding:6px 12px;min-height:40px;font-size:13px;white-space:nowrap}.tool:hover{background:var(--soft)}.menu-toggle{display:none}.layout{max-width:1310px;margin:auto;display:grid;grid-template-columns:292px minmax(0,1fr);gap:76px;padding:42px 42px 80px}.sidebar{position:sticky;top:112px;align-self:start;max-height:calc(100dvh - 138px);overflow:auto;scrollbar-width:thin;padding-right:20px}.eyebrow{font-size:11px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--amber)}.book-title{font:500 28px/1.4 'Noto Serif',Georgia,serif;margin:8px 0 3px}.byline{color:var(--muted);font-size:12px;margin:0 0 25px}.search-label{font-size:12px;font-weight:500;display:block;margin-bottom:7px}.search{width:100%;border:1px solid var(--line);background:var(--paper);border-radius:8px;color:var(--ink);padding:10px 12px;font-size:13px}.search-meta{font-size:11px;color:var(--muted);margin:8px 0 22px}.nav-section{display:block;font-size:12px;font-weight:700;margin:22px 0 10px;text-decoration:none}.toc{list-style:none;padding:0;margin:0}.toc a{display:flex;gap:10px;align-items:baseline;padding:7px 8px;border-left:2px solid transparent;color:var(--muted);font-size:11px;line-height:1.65;text-decoration:none}.toc a:hover,.toc a.active{color:var(--green);border-left-color:var(--green);background:var(--soft)}.toc-num{font-variant-numeric:tabular-nums;opacity:.7;font-size:10px;min-width:17px}.sidebar-foot{font-size:11px;color:var(--muted);border-top:1px solid var(--line);margin-top:24px;padding-top:16px}.content{min-width:0;max-width:760px}.hero{padding:7px 0 34px;border-bottom:1px solid var(--line);margin-bottom:40px}.chapter-label{display:flex;align-items:center;gap:12px;color:var(--green);font-size:12px;font-weight:600;margin-bottom:18px}.chapter-label:before{content:'';width:26px;height:1px;background:var(--green)}h1{font:500 clamp(32px,3.4vw,49px)/1.32 'Noto Serif',Georgia,serif;letter-spacing:-.025em;margin:0 0 22px}h1 em{font-style:normal;color:var(--green)}.intro{color:var(--muted);font-size:15px;max-width:600px;margin:0 0 22px}.meta{display:flex;flex-wrap:wrap;gap:9px 20px;font-size:11px;color:var(--muted)}.legend{display:flex;flex-wrap:wrap;gap:8px 20px;font-size:11px;padding:14px 0 0}.legend span{display:flex;align-items:center;gap:7px}.dot{display:inline-block;width:8px;height:8px;border-radius:50%;background:#bbc1b5}.dot.green{background:var(--green)}.section{margin-bottom:54px}.section-head{display:flex;align-items:flex-start;gap:17px;margin:40px 0 25px}.section-number{font:400 33px/1.25 'Noto Serif',Georgia,serif;color:var(--amber);opacity:.8}.section h2{font:500 24px/1.5 'Noto Serif',Georgia,serif;margin:0 0 5px}.section-head p{font-size:11px;color:var(--muted);margin:0}.situation{padding:27px 0 32px;border-top:1px solid var(--line);scroll-margin-top:105px}.case-meta{display:flex;align-items:center;gap:9px;font-size:10px;font-weight:600;color:var(--muted);letter-spacing:.12em;text-transform:uppercase;margin-bottom:9px}.case-emoji{font-size:20px;letter-spacing:0}.situation h3{font-weight:600;font-size:19px;line-height:1.65;margin:0 0 20px;letter-spacing:-.02em}.answer{padding:19px 23px 20px;border-radius:4px;margin-top:12px}.answer.normal{background:var(--normal)}.answer.clever{background:var(--soft);border-left:3px solid var(--green)}.answer-label{font-weight:600;font-size:11px;display:flex;align-items:center;gap:7px;margin-bottom:9px;color:var(--muted)}.clever .answer-label{color:var(--green)}.answer p{margin:0}.answer p+p{margin-top:17px;padding-top:17px;border-top:1px solid var(--line)}.endnote{border-top:1px solid var(--line);padding:30px 0;color:var(--muted);font-size:12px}.endnote strong{font-weight:500;color:var(--ink)}.endnote a{display:inline-block;margin-top:8px}.footer{max-width:1226px;margin:auto;padding:24px 42px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:16px;font-size:11px;color:var(--muted)}.empty{padding:30px 0;color:var(--muted)}[hidden]{display:none!important}.backdrop{display:none}body.no-scroll{overflow:hidden}
@media(min-width:1500px){.layout{gap:95px}}@media(max-width:1050px){.layout{gap:40px;grid-template-columns:240px minmax(0,1fr);padding:32px 26px 60px}.topbar{padding:0 26px}.top-label{display:none}.sidebar{padding-right:10px}.answer{padding:17px 19px}.content{max-width:760px}}
@media(max-width:780px){body{--size:16px}.topbar{height:66px;padding:0 18px}.brand{font-size:14px}.brand-icon{width:29px;height:29px;font-size:19px}.tools{gap:5px}.tool{padding:5px 9px;min-height:38px;font-size:12px}.menu-toggle{display:inline-block}.layout{display:block;padding:29px 22px 35px}.sidebar{display:none;position:fixed;z-index:55;top:66px;left:0;bottom:auto;height:calc(100dvh - 66px);max-height:calc(100dvh - 66px);overscroll-behavior:contain;width:min(340px,88vw);background:var(--paper);padding:26px 23px 40px}.sidebar.open{display:block}.backdrop.open{display:block;position:fixed;inset:66px 0 0;background:#071b1366;z-index:50}.content{margin:auto}.hero{padding:5px 0 27px;margin-bottom:28px}h1{font-size:34px;line-height:1.35}.intro{font-size:14px}.section-head{margin:30px 0 22px;gap:13px}.section h2{font-size:22px}.section-number{font-size:29px}.situation{padding:24px 0 27px}.situation h3{font-size:18px}.answer{padding:17px 18px}.footer{padding:20px 22px;font-size:10px}.print-button{display:none}.section{margin-bottom:35px}}
@media(max-width:380px){.layout{padding-left:17px;padding-right:17px}.topbar{padding:0 12px}.brand{gap:7px}.brand-text{font-size:12px}.tool{padding:5px 7px}h1{font-size:30px}.answer{padding:15px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media print{body,body.dark{--paper:#fff;--bg:#fff;--ink:#111;--muted:#444;--line:#ccc;--soft:#f4f6f4;--green:#164c37;--normal:#f5f5f5;font-size:11pt}.topbar,.sidebar,.progress,.tools,.backdrop,.footer,.legend,.search-meta{display:none!important}.layout{display:block;max-width:none;padding:0}.content{max-width:none}.hero{margin-bottom:20px;padding:0 0 18px}h1{font-size:28pt}.situation{break-inside:avoid}.answer{padding:12px 16px;print-color-adjust:exact}.section-head{break-after:avoid}.section h2{font-size:18pt}.endnote{font-size:9pt}}