:root{--bg:#f5f5ef;--paper:#fffef9;--ink:#22372f;--muted:#778079;--line:#dfe3d8;--green:#204c3e;--dark:#193e35;--lime:#d1e5a8;--soft:#eaf0e1;--orange:#b9794a}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font:14px/1.7 -apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans CJK SC","Microsoft YaHei",sans-serif}button,input{font:inherit}button,a,input,summary{ -webkit-tap-highlight-color:transparent}a{color:inherit;text-decoration:none}button{cursor:pointer}button:disabled{opacity:.45;cursor:default}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid #a1bd6f;outline-offset:4px}button{color:var(--ink)}.skip{position:fixed;top:-60px;left:20px;background:var(--lime);z-index:100;padding:10px}.skip:focus{top:10px}.sidebar{width:238px;position:fixed;inset:0 auto 0 0;background:#edf0e5;border-right:1px solid #dce2d3;padding:32px 19px 20px;z-index:20;display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:11px;margin:0 9px 38px}.brand-icon{background:var(--dark);color:var(--lime);height:41px;width:41px;border-radius:12px;font:italic 36px/38px Georgia;text-align:center}.brand>span:last-child{font:21px/1.2 Georgia;letter-spacing:1px}.brand b{font:10px/1.2 sans-serif;letter-spacing:1.6px}.brand small{display:block;font:10px/1.8 sans-serif;letter-spacing:1.5px;color:#6e7d69;margin-top:5px}.side-label{font-size:10px;letter-spacing:1.4px;color:#89917e;padding:0 12px 12px;display:flex;justify-content:space-between}.private{font-size:10px;color:#647759;letter-spacing:.5px}.side-link{padding:11px 13px;border-radius:7px;display:flex;gap:11px;align-items:center;font-size:13px;color:#536348;transition:background .15s}.side-link.active{background:var(--dark);color:#f4f7ed}.side-link:hover{background:#dde5d0}.side-link.active:hover{background:var(--dark)}.side-link>span:first-child{font-size:17px;line-height:1}.path-label{margin-top:31px}.path-label span{letter-spacing:1px}.chapter-link{padding:10px 12px;display:flex;gap:12px;align-items:center;color:#67725f;border-radius:6px;margin:3px 0;font-size:12px;position:relative}.chapter-link:after{content:'';width:4px;height:4px;background:#b5bfa6;border-radius:50%;margin-left:auto}.chapter-link.active{color:var(--green);background:#dde6cf;font-weight:600}.chapter-link.done:after{content:'✓';font-size:11px;width:auto;height:auto;background:none;color:#517d3d}.chapter-num{font:11px/1.5 Georgia;color:#96a184;letter-spacing:.8px}.side-divider{height:1px;background:#d7dfcb;margin:24px 10px 12px}.new{font:8px monospace;color:#63835a;padding:2px 5px;background:#e0e9d5;border-radius:3px;margin-left:auto;letter-spacing:1px}.side-bottom{margin-top:auto;padding:30px 12px 0}.progress-label{display:flex;justify-content:space-between;font-size:10px;color:#69795b}.progress-track{height:4px;border-radius:3px;background:#dce4d1;margin:9px 0}.progress-track i{display:block;height:100%;width:0;background:#729556;border-radius:3px;transition:width .3s}.side-bottom small{font-size:9px;color:#94a084}.workspace{margin-left:238px}.topbar{height:77px;border-bottom:1px solid var(--line);padding:0 42px;display:flex;align-items:center;justify-content:space-between;background:#f8f9f2;gap:15px}.breadcrumb{font-size:11px;color:#8c9488;letter-spacing:.5px}.breadcrumb span{margin:0 14px;color:#bcc3b4}.breadcrumb strong{font-weight:500;color:#56644d}.top-actions{display:flex;align-items:center;gap:24px}.search-button{display:flex;align-items:center;gap:9px;background:none;border:none;font-size:11px;color:#77856b}.search-button>span{font-size:24px;line-height:1}.search-button kbd{border:1px solid #dce2d1;width:19px;border-radius:4px;font:10px/19px monospace;margin-left:13px}.avatar{background:#e1e8d4;color:#5f7455;width:30px;height:30px;line-height:30px;text-align:center;border-radius:50%;font-size:11px}.icon-button{border:0;background:transparent;font-size:23px;padding:4px 10px}.topbar>#mobile-menu{display:none}main{max-width:1500px;margin:auto;padding:42px 48px 60px;min-height:calc(100vh - 140px)}main:focus{outline:none}.eyebrow{display:flex;gap:9px;align-items:center;color:#7d8a6c;letter-spacing:2px;font:10px/1.5 sans-serif;text-transform:uppercase;margin-bottom:17px}.eyebrow:before{content:'';width:7px;height:7px;background:#8ba66a;border-radius:50%}h1,h2,h3,p{margin:0}h1{font-family:Georgia,"Noto Serif CJK SC","Songti SC","SimSun",serif;font-weight:500;font-size:38px;line-height:1.45;letter-spacing:1px}h1 em{font-style:normal;color:#6b8951}h2{font-size:21px;font-weight:500;letter-spacing:.6px}h3{font-size:15px;font-weight:600}.page-intro{display:flex;justify-content:space-between;align-items:flex-end;margin-bottom:31px;gap:24px}.subtitle{color:#7e8777;font-size:12px;line-height:1.9;margin-top:13px}.primary,.secondary{display:inline-flex;align-items:center;justify-content:center;gap:18px;padding:11px 18px;border-radius:5px;border:1px solid var(--green);font-size:12px;white-space:nowrap}.primary{background:var(--green);color:white}.primary:hover{background:#30614d}.secondary{background:transparent;border-color:#cfd9c2;color:#4e6543}.secondary:hover{background:#eaf0e0}.arrow{font-size:17px;font-family:serif}.overview-hero{display:grid;grid-template-columns:1.14fr 1fr;border-radius:10px;overflow:hidden;border:1px solid #d6ddcb;min-height:298px}.model-card{background:var(--dark);color:#f0f4e6;padding:29px 30px;position:relative}.card-overline{font-size:9px;letter-spacing:2px;color:#a3b99a;display:flex;justify-content:space-between}.model-card h2{font:23px/1.6 Georgia,"SimSun",serif;letter-spacing:.5px;margin:16px 0 12px}.model-card .math{font-size:15px;color:#e6efce;padding:12px 0;margin:0}.model-card .katex-display>.katex{max-width:none}.model-tags{display:flex;gap:22px;font-size:10px;letter-spacing:.5px;margin-top:19px;color:#bdcdb0}.model-tags i{display:inline-block;width:6px;height:6px;background:#c5d998;border-radius:50%;margin-right:7px}.model-tags span:nth-child(2) i{background:#d1ad78}.model-tags span:nth-child(3) i{background:#a6c5bd}.model-foot{font-size:10px;color:#a6ba9d;border-top:1px solid #41604c;margin-top:25px;padding-top:13px}.lattice-card{padding:23px 25px;background:#e8eddc;display:flex;flex-direction:column}.viz-header{display:flex;justify-content:space-between;align-items:center;font-size:10px;color:#718264}.mini-badge{font:9px/1.7 monospace;border:1px solid #c4d0b1;border-radius:4px;padding:1px 7px;letter-spacing:.4px}.hero-plot{width:100%;height:174px;overflow:visible;margin:3px 0}.mini-control{display:flex;gap:15px;align-items:center;font-size:10px;color:#627652;margin-top:auto}.mini-control input{flex:1;min-width:30px}.mini-control output{font:11px monospace;white-space:nowrap;color:#47633d}.viz-note{font-size:9px;color:#8d9a7f;margin-top:8px}input[type=range]{accent-color:#577d46;height:4px;cursor:pointer}.section-heading{display:flex;justify-content:space-between;align-items:center;margin:35px 0 17px}.section-heading h2{font-size:19px}.section-heading p{color:#8b9680;font-size:10px}.path-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.path-card{display:block;background:var(--paper);border:1px solid var(--line);border-radius:7px;padding:17px 17px 15px;min-height:137px;transition:transform .18s,border-color .18s}.path-card:hover{transform:translateY(-3px);border-color:#8da675}.path-card-top{display:flex;align-items:center;justify-content:space-between;font:italic 17px Georgia;color:#9eaf8a}.path-card-top small{font:9px sans-serif;color:#82966e}.path-card h3{font-size:12px;font-weight:600;margin-top:10px}.path-card p{font-size:10px;color:#929a8a;line-height:1.8;margin-top:5px}.questions{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.question-link{display:flex;align-items:flex-start;gap:10px;background:#ecefdf;border:1px solid #dfe4d1;border-radius:6px;padding:15px;font-size:11px;line-height:1.8}.question-link>span:first-child{font:italic 21px Georgia;color:#8ba46e}.question-link .arrow{margin-left:auto;color:#7e916b;line-height:1.5}.question-link:hover{background:#e1e9d2}.lab-teaser{margin-top:30px;padding:25px 27px;border:1px solid #d6dfc7;border-radius:7px;background:#e8edde;display:flex;justify-content:space-between;align-items:center;gap:20px}.lab-teaser h3{font-weight:500;font-size:17px}.lab-teaser p{font-size:11px;color:#80916f;margin-top:6px}.tiny-label{font-size:9px;letter-spacing:1.4px;color:#8c997d}.read-layout{display:grid;grid-template-columns:minmax(0,1fr) 226px;gap:28px}.reading-head h1{font-size:30px;margin-bottom:12px}.reading-head .subtitle{margin-top:0}.reading-card{border:1px solid var(--line);background:var(--paper);border-radius:8px;padding:25px;margin-top:23px;overflow:hidden}.reading-card .equation-label{font-size:9px;letter-spacing:1.5px;color:#899e70}.math{overflow-x:auto;padding:12px 2px;margin:6px 0;font-size:16px}.math .katex-display{margin:.35em 0}.math.inline{display:inline;padding:0;margin:0;overflow:visible}.physical-meaning{border-left:2px solid #a0ba76;padding-left:14px;font-size:12px;line-height:2;color:#627257;margin-top:14px}.physical-meaning strong{display:block;color:#4c6740;font-weight:500;margin-bottom:4px}.assumption{font-size:11px;padding:14px 17px;background:#e9eedd;border:1px solid #dce4cc;border-radius:5px;color:#758367;line-height:1.9;margin:16px 0 26px}.assumption b{color:#536c43;font-weight:500}.steps-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:13px}.steps-head h2{font-size:17px}.text-button{background:none;border:none;color:#748d58;font-size:10px;padding:5px}.derivation-step{background:var(--paper);border:1px solid var(--line);border-radius:6px;margin:10px 0}.derivation-step summary{list-style:none;cursor:pointer;display:flex;gap:13px;align-items:center;font-size:12px;padding:17px 18px}.derivation-step summary::-webkit-details-marker{display:none}.step-number{font:italic 15px Georgia;color:#91a879}.derivation-step summary:after{content:'+';margin-left:auto;font:19px Georgia;color:#8b9e77}.derivation-step[open] summary:after{content:'−'}.derivation-step[open] summary{border-bottom:1px solid #edf0e6}.step-content{padding:14px 22px 21px}.step-content p{font-size:12px;line-height:2;color:#7a8770;margin-top:10px}.faq-title{display:flex;gap:10px;align-items:center;font-size:16px;margin:31px 0 13px;font-weight:500}.faq-title span{font:italic 22px Georgia;color:#8ea36d}.faq{background:#edf0e3;border-color:#dfe5d2}.faq .step-content{font-size:12px;color:#627455;line-height:2}.lesson-bottom{display:flex;justify-content:space-between;align-items:center;gap:12px;border-top:1px solid var(--line);padding-top:22px;margin-top:28px;flex-wrap:wrap}.lesson-aside{padding-top:7px}.note-box{border:1px solid #dce3ce;border-radius:6px;padding:20px;margin-bottom:18px;background:#f0f2e6}.note-box h3{font-size:11px;font-weight:500;letter-spacing:.5px;margin-bottom:16px}.note-box dl{margin:0}.note-box dt{font:italic 18px Georgia;margin-top:16px;color:#5f7e46}.note-box dd{margin:6px 0 0;font-size:10px;color:#849078;line-height:1.9}.note-box p{color:#849078;font-size:11px;line-height:2}.note-box a{font-size:10px;display:block;color:#597641;margin-top:13px}.note-box.dark{background:var(--dark);color:#e7efd7;border:0}.note-box.dark p{color:#acc09b}.reading-progress{font-size:10px;color:#8d9a7d;margin-bottom:13px}.lesson-mini-path{list-style:none;padding:0;margin:0}.lesson-mini-path li{font-size:10px;color:#8d9b7e;border-left:1px solid #ced8bd;padding:7px 0 7px 12px}.lesson-mini-path li.current{border-left:2px solid #759955;color:#4d713a}.lab-top{margin-bottom:26px}.lab-top h1{font-size:31px}.tabs{display:flex;gap:30px;border-bottom:1px solid var(--line);margin-bottom:26px}.tab{background:none;border:0;border-bottom:2px solid transparent;padding:12px 1px;color:#8a957e;font-size:12px}.tab.active{color:#365c2f;border-color:#6e914e}.lab-grid{display:grid;grid-template-columns:278px minmax(0,1fr);gap:23px}.panel{border:1px solid var(--line);border-radius:8px;background:var(--paper);padding:23px;min-width:0}.panel h2{font-size:16px;margin-bottom:7px}.panel-sub{font-size:10px;color:#95a087}.control{margin-top:27px}.control label{display:flex;justify-content:space-between;font-size:12px;align-items:center}.control output{font:19px Georgia;color:#527a3b}.control input{width:100%;margin:20px 0 9px}.range-ends{display:flex;justify-content:space-between;font-size:9px;color:#95a286}.control p{font-size:10px;line-height:1.9;color:#8b987b;margin-top:10px}.preset-row{display:flex;gap:6px;margin-top:24px;flex-wrap:wrap}.preset{border:1px solid #d9e1cb;background:#f3f5ec;border-radius:4px;padding:7px 9px;font-size:9px;color:#758963}.preset:hover,.preset.active{background:#e4edda;border-color:#9cb685;color:#4a6c37}.reset{font-size:10px;color:#8d9d7d;background:none;border:none;margin-top:20px;padding:0}.lab-def{font-size:10px;color:#8e9d7f;line-height:2;border-top:1px solid var(--line);padding-top:17px;margin-top:25px}.chart-title{display:flex;justify-content:space-between;align-items:center;gap:15px}.live-status{font:9px monospace;letter-spacing:.5px;color:#6a8b51;background:#edf3e2;border-radius:4px;padding:4px 8px;white-space:nowrap}.metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:20px}.metric{background:#edf1e4;border-radius:5px;padding:15px}.metric small{font-size:9px;color:#879776;display:block}.metric strong{font:28px/1.8 Georgia;color:#426437}.metric .unit{font-size:10px;margin-left:5px;color:#91a37d}.metric p{font-size:9px;color:#8b9c7b}.chart-svg{display:block;width:100%;height:260px;margin-top:17px}.chart-legend{display:flex;gap:13px;font-size:9px;color:#8a977d;flex-wrap:wrap;justify-content:center}.chart-legend i{display:inline-block;width:7px;height:7px;border-radius:2px;margin-right:5px}.lab-insight{font-size:11px;color:#748367;line-height:1.9;margin-top:18px;border-left:2px solid #9caf7d;padding-left:13px}.lab-insight strong{font-weight:500;color:#52723f}.lab-warning{font-size:10px;line-height:1.9;color:#9c805f;background:#f5efdf;border:1px solid #e9dfc4;border-radius:4px;padding:12px 15px;margin-top:17px}.experiment-bottom{display:grid;grid-template-columns:1fr 1fr;gap:23px;margin-top:23px}.fock-row{display:flex;align-items:center;gap:12px;margin-top:13px;font-size:11px}.fock-row code{color:#6b8353;width:86px;font-family:monospace}.prob-track{height:6px;background:#eef1e6;flex:1;border-radius:3px}.prob-track i{height:100%;display:block;background:#a0b97c;border-radius:3px}.fock-row span{font:10px monospace;color:#8c9d7a;width:40px;text-align:right}.mini-equation{font:12px/2 Georgia;color:#6c8156}.method{margin-top:25px}.method summary{font-size:11px;color:#8a987a;cursor:pointer}.method p{font-size:11px;line-height:2;color:#8c997e;margin:15px 0}.method .math{font-size:13px}.tunnel-controls{display:flex;align-items:center;gap:20px;margin-top:18px}.tunnel-controls input{flex:1;min-width:20px}.tunnel-controls output{font:11px monospace;white-space:nowrap}.optical-metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:20px}.optical-formula .math{font-size:13px}.optical-bottom{display:flex;justify-content:space-between;align-items:center;margin-top:20px;gap:15px}.optical-bottom p{font-size:10px;color:#8c9d7c}.sources{max-width:900px}.sources h1{font-size:30px}.source-card{background:var(--paper);border:1px solid var(--line);border-radius:7px;padding:25px;margin-top:20px}.source-card h2{font-size:17px;margin-bottom:13px}.source-card p,.source-card li{font-size:12px;color:#7a886e;line-height:2}.source-card ul{padding-left:18px}.source-card a{color:#5a7d40;text-decoration:underline;text-underline-offset:4px}.reference-number{font:italic 21px Georgia;color:#9eae88;margin-right:12px}.reference-entry{margin:20px 0}.reference-entry p{margin-top:7px;padding-left:38px}.formula-table{width:100%;border-collapse:collapse;margin-top:16px;font-size:11px}.formula-table td{border-top:1px solid var(--line);padding:12px 8px;color:#819170}.formula-table td:first-child{width:110px;color:#4f703b;font-family:Georgia;font-size:15px}footer{max-width:1500px;margin:0 auto;border-top:1px solid var(--line);padding:22px 48px;display:flex;align-items:center;gap:17px;font:8px/1.7 sans-serif;letter-spacing:1.7px;color:#a0ab91}footer span{font-size:9px;letter-spacing:.4px}footer a{margin-left:auto;font-size:9px;letter-spacing:.3px}dialog{border:1px solid #d4dfc5;border-radius:12px;padding:25px;background:var(--paper);width:570px;max-width:calc(100% - 32px);max-height:82vh;color:var(--ink);box-shadow:0 20px 100px #132b3a33}dialog::backdrop{background:#1e382b66;backdrop-filter:blur(3px)}.dialog-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:20px}.dialog-head h2{font-size:20px}dialog input{width:100%;background:#f0f3e7;border:1px solid #d8e2c9;padding:12px;border-radius:6px;font-size:12px;color:#536d40}#glossary-results{margin-top:15px}.gloss-item{display:block;width:100%;text-align:left;background:none;border:0;border-bottom:1px solid #e2e8d9;padding:16px 6px;cursor:pointer}.gloss-item strong{font-size:13px;font-weight:500;color:#52723f}.gloss-item p{font-size:11px;line-height:1.9;color:#869578;margin-top:4px}.empty{padding:30px;color:#8c9b7e;font-size:12px}#toast{position:fixed;bottom:25px;left:calc(50% + 90px);transform:translate(-50%,20px);background:#234f3c;color:#eef5e3;padding:11px 22px;border-radius:6px;font-size:12px;opacity:0;pointer-events:none;transition:all .2s;z-index:100}#toast.visible{opacity:1;transform:translate(-50%,0)}.tunnel-viz{width:100%;height:140px;margin:10px 0}.mob-shade{display:none}.show{display:block}.katex .base{white-space:nowrap}@media(min-width:1600px){main{padding-top:55px}.overview-hero{min-height:330px}.hero-plot{height:205px}.model-card{padding:33px 38px}.model-card .math{font-size:18px}.path-card{min-height:155px;padding:20px}.path-card h3{font-size:14px}.path-card p{font-size:11px}}@media(max-width:1180px){.sidebar{width:215px;padding-left:12px;padding-right:12px}.workspace{margin-left:215px}main{padding:32px 30px 48px}.topbar{padding:0 30px}.overview-hero{grid-template-columns:1fr 1fr}.model-card{padding:22px}.model-card .math{font-size:13px}.model-tags{gap:12px}.read-layout{grid-template-columns:minmax(0,1fr) 195px;gap:20px}.lab-grid{grid-template-columns:240px minmax(0,1fr);gap:16px}.panel{padding:19px}.metric strong{font-size:24px}.metrics{gap:8px}.metric{padding:11px}.path-grid{grid-template-columns:repeat(2,1fr)}.path-card{min-height:122px}.questions{grid-template-columns:1fr}.question-link{align-items:center}h1{font-size:33px}.reading-head h1{font-size:27px}}@media(max-width:900px){.read-layout{grid-template-columns:1fr}.lesson-aside{display:grid;grid-template-columns:1fr 1fr;gap:15px}.lesson-aside .note-box:last-child{display:none}.overview-hero{grid-template-columns:1fr}.model-card .math{font-size:17px}.model-card{min-height:260px}.lattice-card{min-height:260px}.hero-plot{height:160px}.lab-grid{grid-template-columns:1fr}.controls-panel{display:grid;grid-template-columns:1fr 1fr;gap:0 25px}.controls-panel>h2,.controls-panel>.panel-sub{grid-column:1/-1}.lab-def{grid-column:1/-1}.experiment-bottom{grid-template-columns:1fr}.metrics{grid-template-columns:repeat(3,1fr)}.page-intro{align-items:flex-start;flex-direction:column;gap:17px}.lab-teaser{align-items:flex-start;flex-direction:column}.top-actions{gap:14px}}@media(max-width:700px){.sidebar{transform:translateX(-100%);width:238px;box-shadow:0 0 0 100vw #263f2e55;visibility:hidden;transition:transform .18s,visibility .18s}.sidebar.mobile-open{transform:translateX(0);visibility:visible}.workspace{margin-left:0}.topbar{height:65px;padding:0 18px;gap:10px}.topbar>#mobile-menu{display:block}.breadcrumb{font-size:10px;flex:1}.breadcrumb span{margin:0 6px}.top-actions{gap:12px}.search-button{font-size:0;padding:0}.search-button kbd{display:none}.search-button>span{font-size:26px}.avatar{height:27px;width:27px;line-height:27px}main{padding:29px 21px 42px}h1{font-size:29px;letter-spacing:.3px}.subtitle{font-size:11px}.eyebrow{font-size:8px}.overview-hero{min-height:0}.model-card{padding:25px 21px}.model-card .math{font-size:15px}.model-tags{gap:18px}.section-heading p{display:none}.section-heading h2{font-size:18px}.path-card{padding:15px;min-height:133px}.path-card h3{font-size:11px}.path-card p{font-size:9px}.lesson-aside{grid-template-columns:1fr}.note-box{padding:20px}.lesson-aside .note-box:last-child{display:block}.note-box dl{display:grid;grid-template-columns:1fr 1fr}.note-box dt{margin:0}.note-box dd{margin:0 0 15px}.reading-card{padding:20px}.reading-head h1{font-size:25px}.reading-card .math{font-size:14px}.step-content{padding:12px 17px 18px}.math{font-size:14px}.derivation-step summary{font-size:11px;padding:15px}.lab-top h1{font-size:27px}.controls-panel{grid-template-columns:1fr}.metrics{gap:7px}.metric{padding:12px 9px}.metric strong{font-size:24px}.metric p{font-size:8px}.metric small{font-size:8px}.chart-svg{height:230px}.optical-metrics{gap:7px}.optical-bottom{align-items:flex-start;flex-direction:column}.tabs{gap:22px}.tab{font-size:11px}.tunnel-controls{gap:9px}footer{padding:22px 21px;flex-wrap:wrap;gap:9px}footer span{display:none}footer a{font-size:8px}.lesson-bottom .secondary,.lesson-bottom .primary{padding:9px 12px;font-size:10px}.source-card{padding:20px}#toast{left:50%;width:max-content;max-width:90%}.optical-formula .math{font-size:12px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
@media(max-width:700px){.sidebar{pointer-events:none}.sidebar.mobile-open{pointer-events:auto}}
