:root{color-scheme:light dark;--paper:#fdfdfc;--ink:#20242b;--muted:#626a74;--line:#d9dee6;--accent:#3157c8;--blue-tint:#eef2fc;--panel:#f5f7fb;--file:#fff;--forest:#315f57}
@media(prefers-color-scheme:dark){:root{--paper:#181c23;--ink:#e8ebf0;--muted:#aab2bf;--line:#3a4351;--accent:#9ab2ff;--blue-tint:#252e45;--panel:#202733;--file:#1b222d;--forest:#9bd0bf}}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:2rem}
body{min-width:320px;margin:0;background:var(--paper);color:var(--ink);font:18px/1.82 "Iowan Old Style","Source Serif Pro","Source Serif",Georgia,"Times New Roman","Songti SC","STSong",serif}
body a{color:inherit;text-decoration-color:var(--accent);text-underline-offset:.21em}
body a:hover{color:var(--accent)}
body a:focus-visible{outline:2px solid var(--accent);outline-offset:4px;border-radius:2px}
.page-shell{width:min(100% - 3rem,1100px);margin-inline:auto}
.back-link{display:inline-block;margin:2.4rem 0 0;color:var(--muted);font:600 .83rem/1.5 system-ui,sans-serif;text-decoration:none}
.back-link::before{content:"←";margin-right:.55rem;color:var(--accent)}
.hero{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(350px,.95fr);align-items:center;gap:clamp(2rem,5vw,5rem);padding:4.3rem 0 5.5rem;border-bottom:1px solid var(--line)}
.type-line,.section-kind{font:650 .8rem/1.5 system-ui,"Microsoft YaHei",sans-serif;color:var(--accent)}
.type-line{margin:0 0 2.1rem}
.type-line span{margin:0 .4rem;color:var(--line)}
h1,h2,h3,p,figure{margin-top:0}
h1{margin-bottom:1.6rem;font-size:clamp(3.6rem,6.5vw,6.25rem);font-weight:500;line-height:1.11;letter-spacing:-.065em;text-wrap:balance}
.full-stop{color:var(--accent)}
.hero-dek{max-width:33em;margin:0 0 1.8rem;color:var(--muted);font-size:1.15rem;line-height:1.85}
.hero-jump{font:650 .85rem/1.5 system-ui,sans-serif;text-decoration:none;color:var(--accent)}
.hero-jump span{display:inline-block;margin-left:.45rem}
.file-figure{margin:0}
.file-window{overflow:hidden;border:1px solid #bfcbe2;border-radius:8px;background:var(--file);box-shadow:0 24px 65px rgba(34,58,107,.09)}
.file-window__top{display:flex;justify-content:space-between;align-items:center;padding:.82rem 1.2rem;border-bottom:1px solid var(--line);font:600 .75rem/1.5 system-ui,sans-serif;color:var(--muted)}
.file-window__top span:last-child{color:var(--accent);font-size:1.5rem;line-height:1}
.tree{padding:1.7rem 1.4rem 1.9rem;font:600 .94rem/1.7 Consolas,"SFMono-Regular",monospace}
.tree-row{display:grid;grid-template-columns:2rem minmax(0,1fr);align-items:baseline;gap:.35rem;padding:.5rem .35rem;white-space:nowrap}
.tree-row.root{color:var(--accent);font-weight:700}
.tree-children{margin-left:.95rem;padding-left:.85rem;border-left:1px solid var(--line)}
.tree-children .tree-row{grid-template-columns:1.6rem minmax(0,1fr) auto;border-radius:4px}
.tree-children .tree-row.primary{background:var(--blue-tint);color:var(--accent)}
.tree-icon{color:var(--accent);opacity:.75}
.tree small{font:500 .69rem/1.5 system-ui,"Microsoft YaHei",sans-serif;color:var(--muted)}
.file-window__foot{display:flex;align-items:center;justify-content:center;gap:.5rem;padding:.95rem;border-top:1px solid var(--line);font:600 .69rem/1.5 system-ui,"Microsoft YaHei",sans-serif;color:var(--forest)}
.file-window__foot i{display:block;width:1.1rem;height:1px;background:var(--forest);transform-origin:left center;animation:draw-line .8s ease-out both}
.file-window__foot i:nth-of-type(2){animation-delay:.18s}.file-window__foot i:nth-of-type(3){animation-delay:.36s}
.file-figure figcaption{margin-top:.7rem;color:var(--muted);font:400 .76rem/1.6 system-ui,"Microsoft YaHei",sans-serif;text-align:center}
@keyframes draw-line{from{transform:scaleX(0);opacity:0}to{transform:scaleX(1);opacity:1}}
.reading-layout{display:grid;grid-template-columns:190px minmax(0,1fr);gap:clamp(3rem,7vw,6.8rem);padding:3.6rem 0 6rem}
.contents{position:sticky;top:2rem;align-self:start;font:500 .78rem/1.5 system-ui,"Microsoft YaHei",sans-serif}
.contents p{margin:0 0 .9rem;color:var(--muted);font-weight:700}
.contents a{display:block;padding:.5rem 0 .5rem .8rem;border-left:1px solid var(--line);color:var(--muted);text-decoration:none}
.contents a:hover,.contents a:focus-visible{border-left-color:var(--accent);color:var(--accent)}
.note{min-width:0;max-width:790px}
.note p{max-width:43em}
.note strong{font-weight:700}
.opening{padding-bottom:3.7rem}
.section-kind{margin:0 0 1.2rem}
.note h2{max-width:17em;margin:0 0 1.3rem;font-size:clamp(1.9rem,3vw,2.7rem);font-weight:500;line-height:1.32;letter-spacing:-.04em;text-wrap:balance}
.note p{margin:0 0 1.2rem}
.thesis{margin:2rem 0;padding:1.45rem 1.7rem;background:var(--blue-tint);border-left:3px solid var(--accent)}
.thesis span{display:block;margin-bottom:.65rem;color:var(--accent);font:700 .77rem/1.5 system-ui,"Microsoft YaHei",sans-serif}
.thesis p{margin:0;font-size:1.1rem}
.source-caveat,.small-note{font:.79rem/1.7 system-ui,"Microsoft YaHei",sans-serif;color:var(--muted)}
.note-section{padding:3.8rem 0 4.1rem;border-top:1px solid var(--line)}
.judgment-list{margin:1.8rem 0}
.judgment{display:grid;grid-template-columns:7.2rem 1fr;gap:1rem;padding:1.15rem 0;border-top:1px solid var(--line)}
.judgment:last-child{border-bottom:1px solid var(--line)}
.judgment>strong{color:var(--accent);font:700 .82rem/1.7 system-ui,"Microsoft YaHei",sans-serif}
.judgment p{margin:0;font-size:.96rem}
code{padding:.12em .35em;border-radius:3px;background:var(--panel);font:.82em/1.5 Consolas,"SFMono-Regular",monospace}
.load-flow{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;overflow:hidden;margin:2rem 0;background:var(--line);border:1px solid var(--line);border-radius:5px}
.load-flow>div{padding:1.3rem 1.1rem;background:var(--panel)}
.load-flow span{display:block;margin-bottom:.8rem;color:var(--accent);font:700 .76rem/1.4 system-ui,"Microsoft YaHei",sans-serif}
.load-flow strong{display:block;margin-bottom:.4rem;font-size:.93rem;line-height:1.5}
.load-flow p{margin:0;color:var(--muted);font-size:.83rem;line-height:1.6}
.concept-table-wrap{overflow-x:auto;margin:1.7rem 0 1rem}
.concept-table{width:100%;min-width:560px;border-collapse:collapse;font-size:.88rem;line-height:1.62}
.concept-table th,.concept-table td{padding:.82rem .75rem;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.concept-table thead th{border-top:1px solid var(--line);color:var(--muted);font:700 .76rem/1.5 system-ui,"Microsoft YaHei",sans-serif}
.concept-table tbody th{width:9.5rem;color:var(--accent);font:650 .84rem/1.6 system-ui,"Microsoft YaHei",sans-serif}
.margin-note{margin:1.9rem 0 0;padding:1.3rem 1.55rem;border:1px solid var(--line);background:var(--panel);border-radius:5px}
.margin-note strong{display:block;margin-bottom:.45rem;font-size:.97rem}
.margin-note p{margin:0;color:var(--muted);font-size:.91rem}
.practice-steps{margin:2rem 0;padding:0;list-style:none}
.practice-steps li{position:relative;padding:0 0 1.75rem 3.2rem;border-left:1px solid var(--line)}
.practice-steps li:last-child{border-left-color:transparent;padding-bottom:0}
.step-num{position:absolute;left:-.95rem;top:.02rem;display:grid;place-items:center;width:1.85rem;height:1.85rem;border:1px solid var(--accent);border-radius:50%;background:var(--paper);color:var(--accent);font:700 .78rem/1 system-ui,sans-serif}
.practice-steps strong{display:block;margin-bottom:.2rem;font-size:1rem}
.practice-steps p{margin:0;color:var(--muted);font-size:.92rem}
.decision{margin:2.2rem 0;padding:1.4rem 1.6rem;border-top:2px solid var(--forest);background:var(--panel)}
.decision strong{display:block;color:var(--forest);font:.85rem/1.5 system-ui,"Microsoft YaHei",sans-serif;font-weight:700}
.decision p{margin:.6rem 0 0;font-size:.92rem}
.closing{margin:2.1rem 0 0!important;font-size:1.23rem;line-height:1.7}
.sources{padding:3.7rem 0 1rem;border-top:1px solid var(--line)}
.sources h2{font-size:1.8rem}
.sources ul{padding-left:1.2rem;margin:1.4rem 0 0;color:var(--muted);font-size:.85rem;line-height:1.75}
.sources li{padding:.35rem 0}
.sources a{color:var(--ink)}
@media(max-width:840px){.hero{grid-template-columns:1fr;padding-top:3.2rem}.file-figure{max-width:540px}.reading-layout{display:block;padding-top:2.7rem}.contents{display:none}.note{margin:auto}}
@media(max-width:600px){.page-shell{width:min(100% - 2.4rem,1100px)}.back-link{margin-top:1.7rem}.hero{gap:2.4rem;padding:2.7rem 0 3.7rem}h1{font-size:clamp(3.2rem,12vw,4.8rem)}.hero-dek{font-size:1.04rem}.tree{padding:1.15rem .65rem;font-size:.77rem}.tree-children{margin-left:.55rem;padding-left:.4rem}.tree-children .tree-row{grid-template-columns:1.1rem minmax(0,1fr)}.tree small{display:none}.reading-layout{padding-bottom:4rem}.note-section{padding:3rem 0}.opening{padding-bottom:3rem}.judgment{grid-template-columns:1fr;gap:.25rem}.load-flow{grid-template-columns:1fr}.concept-table{font-size:.81rem}.thesis{padding:1.15rem 1.25rem}}
@media(max-width:380px){.tree small{display:none}.tree-children .tree-row{grid-template-columns:1.1rem minmax(0,1fr)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.file-window__foot i{animation:none}}