:root{--forest:#132b27;--forest-light:#23423b;--paper:#f7f8f3;--white:#fff;--ink:#1c302b;--muted:#63726b;--line:#dce3db;--green:#17664c;--mint:#e4f0e7;--lime:#d9ed9a;--gold:#825c18;--gold-bg:#fcf3df;--red:#9b3832;--red-bg:#fff0ee;--radius:14px;--rail:264px;--shadow:0 12px 30px #132b270b}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.6 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}a{color:var(--green);text-decoration:none}a:hover{text-decoration:underline;text-underline-offset:4px}button,input,select,textarea{font:inherit}button,a,input,select,textarea,summary{outline-offset:4px}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #398767}button{cursor:pointer}button:disabled{cursor:default;opacity:.6}h1,h2,h3,p{margin:0}h1{font-size:clamp(34px,4.4vw,56px);line-height:1.12;letter-spacing:-2px;font-weight:650}h2{font-size:27px;line-height:1.3;letter-spacing:-.7px}h3{font-size:19px;line-height:1.4;letter-spacing:-.3px}small{font-size:12px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.skip-link{position:fixed;left:280px;top:-60px;z-index:50;background:var(--white);padding:12px 20px}.skip-link:focus{top:10px}
.sidebar{position:fixed;inset:0 auto 0 0;width:var(--rail);background:var(--forest);color:#c4d5ce;overflow-y:auto;padding:28px 18px 24px;z-index:25;scrollbar-width:thin;scrollbar-color:#456055 transparent}.brand{display:flex;gap:13px;align-items:center;color:#fff;padding:0 8px;font-size:24px;letter-spacing:-1px;font-weight:650}.brand:hover{text-decoration:none}.brand-mark{width:40px;height:42px;border:1px solid #779187;border-radius:10px;display:grid;place-content:center;font:700 30px Georgia;position:relative}.brand-mark span{position:absolute;color:var(--lime);right:2px;bottom:1px}.brand-sub{display:block;letter-spacing:1.5px;font-size:8px;font-weight:500;color:#a8c0b5;margin-top:3px}.course-label{font-size:8px;letter-spacing:1.1px;margin:28px 8px 15px;color:#a9c2b7;display:flex;align-items:center;gap:7px}.live-dot{width:5px;height:5px;border-radius:50%;background:var(--lime)}.primary-nav{display:grid;gap:4px;padding-bottom:24px;border-bottom:1px solid #375047}.primary-nav a{display:flex;align-items:center;gap:10px;color:#c4d5ce;padding:9px 11px;border-radius:7px;font-size:12px}.primary-nav a>span{width:18px;font-size:17px;text-align:center}.primary-nav small{margin-left:auto;border:1px solid #526a5f;border-radius:4px;padding:0 4px;font-size:9px}.primary-nav a:hover,.primary-nav a.active{background:#2c493f;color:#fff;text-decoration:none}.rail-heading{font-size:9px;letter-spacing:1.3px;margin:24px 8px 14px;color:#99b4a8;display:flex;justify-content:space-between}.rail-heading span{letter-spacing:0;color:var(--lime)}.track-label{font-size:9px;font-weight:650;color:#93aea1;letter-spacing:.9px;text-transform:uppercase;margin:18px 9px 8px;display:flex;align-items:center;gap:8px}.track-label i{display:block;width:14px;height:1px;background:#5c7769}.lesson-link{display:flex;gap:9px;align-items:flex-start;color:#d0dfd6;padding:8px 9px;font-size:11px;border-radius:6px;line-height:1.5;margin:2px 0}.lesson-link .number{font:10px/1.6 Consolas,monospace;color:#9abaac;width:19px;flex-shrink:0}.lesson-link:hover,.lesson-link.active{background:#2c493f;text-decoration:none;color:#fff}.lesson-link.active{box-shadow:inset 2px 0 var(--lime)}.lesson-link.read .number{color:var(--lime)}.rail-footer{border-top:1px solid #375047;margin:26px 8px 0;padding-top:24px;color:#a4bbaf;font-size:10px;line-height:1.7}.rail-footer p{margin:12px 0}.rail-footer a{color:#b6d4c2}.evidence-chip{font-size:8px;letter-spacing:1px;border:1px solid #647d6e;border-radius:4px;padding:5px 7px;color:#cce1d4}
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main{max-width:1380px;padding:42px 44px 70px;margin:auto;min-height:80vh}main:focus{outline:none}.eyebrow{display:flex;align-items:center;gap:9px;color:var(--green);font-size:10px;letter-spacing:1.7px;font-weight:650;text-transform:uppercase;margin-bottom:20px}.eyebrow:before{content:"";width:21px;height:2px;background:var(--green)}.subtext{font-size:15px;line-height:1.8;color:var(--muted);max-width:65ch;margin-top:20px}.page-head{margin-bottom:32px}.page-head h1{max-width:950px}.button{display:inline-flex;align-items:center;justify-content:center;gap:10px;border:1px solid var(--green);background:var(--green);color:white;border-radius:7px;padding:12px 18px;font-size:12px;font-weight:650;line-height:1.4}.button:hover{background:#0c5039;color:white;text-decoration:none}.button.secondary{background:white;border-color:var(--line);color:var(--ink)}.button.secondary:hover{background:var(--mint)}.button.text-button{background:transparent;border-color:transparent;color:var(--green);padding:9px 0}.actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-top:24px}.badge{display:inline-flex;gap:5px;align-items:center;font-size:9px;letter-spacing:.8px;font-weight:650;text-transform:uppercase;padding:5px 8px;border-radius:4px;background:var(--mint);color:var(--green)}.badge.amber{background:var(--gold-bg);color:var(--gold)}.meta-row{display:flex;gap:18px;flex-wrap:wrap;font-size:11px;color:var(--muted);margin-top:22px;align-items:center}.meta-row span+span:before{content:"·";margin-right:18px;color:#a6b4a7}
.hero{display:grid;grid-template-columns:1.1fr .9fr;gap:35px;padding:12px 0 40px;align-items:center}.hero h1{max-width:580px}.hero h1 em{font-family:Georgia,serif;color:var(--green);font-weight:400;letter-spacing:-1.8px}.hero-visual{position:relative;border:1px solid #cbd9c9;background:#edf3e8;border-radius:18px;min-height:350px;padding:26px;overflow:hidden}.visual-grid{position:absolute;inset:0;background-image:linear-gradient(#c4d1c344 1px,transparent 1px),linear-gradient(90deg,#c4d1c344 1px,transparent 1px);background-size:24px 24px;pointer-events:none}.visual-kicker{position:relative;font:9px Consolas;text-transform:uppercase;letter-spacing:1px;color:#546b58;display:flex;justify-content:space-between}.model-card{position:relative;background:var(--forest);color:white;border-radius:11px;padding:22px;margin:28px auto 0;max-width:280px;box-shadow:0 14px 25px #223e3020}.model-card-top{display:flex;justify-content:space-between;align-items:center;font-size:10px}.model-card h3{font:22px Georgia;margin:10px 0 6px}.model-card p{font-size:10px;color:#a9c6b1}.model-card .pill-row{display:flex;gap:5px;margin-top:20px}.pill-row span{font:8px Consolas;background:#385445;border:1px solid #526e59;padding:4px 6px;border-radius:4px;color:#cfe2cc}.diagram-inputs{position:relative;display:flex;gap:10px;margin:20px 0 0;justify-content:center}.diagram-inputs button{font-size:10px;background:white;border:1px solid #c0d2bc;border-radius:7px;padding:11px 12px;color:var(--ink);box-shadow:0 5px 10px #18302508}.diagram-inputs button[aria-pressed=true]{background:var(--lime);border-color:#8eaa68}.diagram-connector{position:relative;text-align:center;color:#56814f;font-size:20px;height:23px}.diagram-caption{position:relative;font-size:11px;color:#466342;background:white;border:1px solid #cfddca;padding:12px;border-radius:7px;min-height:64px;margin-top:17px}.diagram-foot{position:relative;font:8px Consolas;color:#67815d;margin-top:17px;display:flex;justify-content:space-between}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:23px 0;margin:0 0 28px}.stat strong{font-size:28px;font-weight:550;letter-spacing:-1px}.stat span{display:block;font-size:10px;color:var(--muted);margin-top:2px}.coverage-line{display:flex;gap:11px;align-items:flex-start;font-size:11px;line-height:1.7;color:#766236;border:1px solid #e7d7b3;border-radius:8px;background:#fcf7e9;padding:14px 17px;margin-bottom:38px}.coverage-line .status-symbol{width:18px;height:18px;display:grid;place-items:center;flex-shrink:0;border:1px solid #b69858;border-radius:50%;font:11px Georgia}.coverage-line a{color:#765c28;text-decoration:underline}.section-heading{display:flex;justify-content:space-between;align-items:end;margin:38px 0 20px;gap:15px}.section-heading p{font-size:12px;color:var(--muted);margin-top:7px}.section-heading>a{font-size:11px;white-space:nowrap}.tracks-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.track-card{display:flex;gap:20px;flex-direction:column;background:white;border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}.track-card-top{display:flex;justify-content:space-between;align-items:start}.track-icon{font:21px Georgia;color:var(--green);width:43px;height:43px;border-radius:10px;background:var(--mint);display:grid;place-content:center}.track-card small{font-size:9px;letter-spacing:.7px;color:var(--muted)}.track-card h3{margin-top:3px;font-size:21px}.track-card p{font-size:12px;color:var(--muted);line-height:1.8}.chapter-list{display:grid;gap:0}.chapter-list a{color:var(--ink);display:flex;gap:12px;align-items:center;font-size:11px;padding:9px 0;border-top:1px solid #edf0e9}.chapter-list a>span:first-child{font:10px Consolas;color:#8d9d8e;min-width:20px}.chapter-list a>span:last-child{margin-left:auto;color:var(--green)}.featured-labs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.lab-card,.reference-card{background:white;border:1px solid var(--line);border-radius:var(--radius);padding:23px;display:flex;flex-direction:column;gap:14px}.lab-card .lab-symbol{font:25px Consolas;color:var(--green)}.lab-card h3{font-size:17px}.lab-card p,.reference-card p{font-size:12px;color:var(--muted)}.lab-card>a,.reference-card>a{font-size:11px;margin-top:auto;font-weight:650}.grid-three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 205px;gap:45px}.lesson-article{min-width:0}.lesson-header{border-bottom:1px solid var(--line);padding-bottom:30px;margin-bottom:30px}.lesson-header h1{font-size:clamp(32px,3.3vw,45px);letter-spacing:-1.5px}.reading-goal{background:var(--mint);padding:18px 22px;border-radius:9px;border-left:3px solid var(--green);font-size:12px;margin-bottom:28px}.reading-goal strong{display:block;font-size:9px;letter-spacing:1px;text-transform:uppercase;margin-bottom:5px}.lesson-content,.reference-body{font:17px/1.85 Georgia,"Times New Roman",serif}.lesson-content p,.reference-body p{margin:18px 0;max-width:80ch}.lesson-content h2,.reference-body h2{font:600 25px/1.3 system-ui;letter-spacing:-.7px;margin:38px 0 18px}.lesson-content h3,.reference-body h3{font:600 19px/1.4 system-ui;margin:25px 0 12px}.lesson-content ul,.reference-body ul{padding-left:24px}.lesson-content li,.reference-body li{margin:7px 0}.lesson-toc{position:sticky;top:104px;align-self:start;border-left:1px solid var(--line);padding-left:19px;font-size:10px;max-height:70vh;overflow:auto}.lesson-toc strong{font-size:9px;letter-spacing:1px;color:var(--muted);display:block;margin-bottom:13px}.lesson-toc a{display:block;color:var(--muted);margin:9px 0;line-height:1.6}.lesson-toc .toc-action{display:block;margin-top:22px;border-top:1px solid var(--line);padding-top:18px}.lesson-note{font:12px/1.8 system-ui;background:white;border:1px solid var(--line);border-radius:8px;padding:19px;margin:24px 0}.deep-section{border-top:1px solid var(--line);padding-top:6px;margin-top:30px}.depth-label{font:9px system-ui;letter-spacing:1px;color:var(--green);text-transform:uppercase;margin:26px 0 8px}.note{font:12px/1.8 system-ui;background:var(--mint);border-left:3px solid var(--green);padding:18px 21px;margin:24px 0;border-radius:0 8px 8px 0}.note.gap{background:var(--gold-bg);border-left-color:#ae8744;color:#6e5426}.flow{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin:24px 0}.step{font:11px/1.6 system-ui;background:white;border:1px solid var(--line);border-radius:6px;padding:11px 13px}.arrow{font:16px system-ui;color:var(--green)}table{border-collapse:collapse;width:100%;font:11px/1.7 system-ui;margin:22px 0;display:table}th,td{text-align:left;padding:12px;vertical-align:top;border-bottom:1px solid var(--line);overflow-wrap:anywhere}th{font-size:9px;text-transform:uppercase;letter-spacing:.7px;color:var(--green);background:var(--mint)}td{background:#fff8}code{font:12px/1.6 Consolas,"Courier New",monospace;background:#edf1e8;padding:2px 4px;border-radius:3px;overflow-wrap:anywhere}pre{font:12px/1.7 Consolas,"Courier New",monospace;background:var(--forest);color:#dae8dc;border:1px solid #314c3f;padding:22px;border-radius:9px;overflow:auto;max-width:100%;white-space:pre-wrap;tab-size:2;margin:20px 0}pre code{background:none;color:inherit;padding:0}.sources{font:11px/1.7 system-ui;padding:0!important;list-style:none}.sources>li{border:1px solid var(--line);background:white;border-radius:8px;padding:16px 18px;margin:10px 0}.source-preview{font-size:10px;max-height:280px;overflow:auto}.sources a{overflow-wrap:anywhere}.source-tag{font:9px system-ui;color:var(--green);text-transform:uppercase;letter-spacing:1px}details{font:13px/1.8 system-ui;border:1px solid var(--line);border-radius:8px;padding:14px 18px;background:white;margin:16px 0}summary{cursor:pointer;font-weight:600;color:var(--green)}details>p{margin:13px 0 0!important}.sources details{padding:8px 0 0;border:0;margin:6px 0 0}.sources pre{margin:8px 0 0}.practice-box{padding:24px;background:#edf0e7;border:1px solid #ccd7c6;border-radius:12px;margin:28px 0}.practice-box h2{margin:0 0 12px}.practice-box p{font:14px/1.9 Georgia;margin:0 0 18px}.practice-box details{background:#fafbf7}
.quiz-card{margin:18px 0;padding:24px;background:white;border:1px solid var(--line);border-radius:12px}.quiz-card fieldset{border:0;margin:0;padding:0}.quiz-card legend{font-size:15px;font-weight:600;margin-bottom:14px;line-height:1.6;width:100%}.quiz-number{font:9px Consolas;color:var(--green);letter-spacing:1px;display:block;margin-bottom:9px}.quiz-option{display:flex;gap:11px;align-items:center;border:1px solid var(--line);border-radius:7px;padding:12px 14px;margin:8px 0;font-size:12px;cursor:pointer}.quiz-option:hover{background:#f4f7f0}.quiz-option:has(input:checked){background:var(--mint);border-color:#699a7d}.quiz-option input{accent-color:var(--green);width:15px;height:15px;flex-shrink:0;margin:0}.quiz-feedback{font-size:12px;line-height:1.8;margin-top:14px;padding:12px 15px;border-radius:7px;display:none}.quiz-feedback.visible{display:block}.quiz-feedback.success{background:var(--mint);color:#205a3c}.quiz-feedback.error{background:var(--gold-bg);color:#74561e}.quiz-card .button{margin-top:10px;padding:9px 14px}.quiz-footer{display:flex;gap:16px;align-items:center;flex-wrap:wrap;margin-top:14px;font-size:11px;color:var(--muted)}.chapter-next{display:flex;justify-content:space-between;gap:20px;align-items:center;padding-top:26px;border-top:1px solid var(--line);margin-top:40px}.chapter-next .button{max-width:65%;text-align:left}.completion-note{font-size:10px;color:var(--muted);margin-top:14px}.progress-strip{background:white;border:1px solid var(--line);padding:20px 24px;border-radius:11px;display:flex;gap:25px;align-items:center;margin-bottom:26px}.progress-strip p{font-size:11px;color:var(--muted)}.progress-track{height:5px;width:180px;max-width:100%;background:#e2e9df;border-radius:8px;overflow:hidden;margin:8px 0}.progress-fill{height:100%;background:var(--green)}.toolbar{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin:24px 0}.toolbar label{font-size:11px;color:var(--muted)}select,input.local-search{border:1px solid var(--line);background:white;border-radius:7px;padding:10px 12px;font-size:12px;color:var(--ink)}input.local-search{width:100%;margin:15px 0}.count-note{font-size:11px;color:var(--muted);margin-left:auto}
.lab-overview{border:1px solid #bcd2bc;background:#edf5e9;padding:22px 24px;border-radius:12px;margin:26px 0}.lab-overview .meta-row{margin-top:10px}.lab-overview p{font-size:12px;line-height:1.8}.lab-toolbar{display:flex;justify-content:space-between;gap:16px;align-items:center;flex-wrap:wrap;padding:16px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin:25px 0}.segmented{display:inline-flex;border:1px solid var(--line);padding:3px;background:white;border-radius:8px;gap:3px}.segmented button{background:transparent;border:0;border-radius:5px;padding:8px 13px;font-size:11px;color:var(--muted)}.segmented button[aria-pressed=true]{background:var(--forest);color:white}.lab-toolbar>span{font-size:10px;color:var(--muted)}.stage-tabs{display:flex;gap:5px;flex-wrap:wrap;border-bottom:1px solid var(--line);margin:26px 0 0}.stage-tabs button{background:transparent;border:0;padding:13px 15px;color:var(--muted);font-size:11px;border-bottom:2px solid transparent;display:flex;gap:8px;align-items:center}.stage-tabs button[aria-selected=true]{color:var(--green);border-bottom-color:var(--green);font-weight:650}.stage-tabs button span{font:9px Consolas;background:#e5eadf;border-radius:4px;padding:1px 5px;color:var(--muted)}.lab-panel{background:white;border:1px solid var(--line);border-top:0;border-radius:0 0 12px 12px;padding:26px;min-height:390px}.payload-layout{display:grid;grid-template-columns:minmax(0,1.5fr) minmax(180px,.7fr);gap:25px}.payload-layout pre{margin:0}.payload-notes h3{font-size:13px;margin-bottom:12px}.annotation{padding:14px 0;border-top:1px solid var(--line);font-size:11px;color:var(--muted);line-height:1.8}.annotation strong{display:block;font:11px Consolas;color:var(--green);margin-bottom:5px}.payload-label{display:flex;justify-content:space-between;font-size:10px;color:var(--muted);margin-bottom:12px;align-items:center}.copy-button{background:#edf2e9;color:var(--green);border:1px solid #d1dec9;border-radius:5px;padding:5px 9px;font-size:10px}.validation-list{list-style:none;padding:0;margin:20px 0;display:grid;gap:12px}.validation-list li{display:flex;gap:10px;font-size:13px;line-height:1.8;padding:14px 17px;background:var(--mint);border-radius:7px}.validation-list li:before{content:"✓";color:var(--green);font-weight:700}.failure-callout{background:var(--red-bg);border-left:3px solid var(--red);border-radius:0 8px 8px 0;padding:20px;color:#793a32;font-size:13px;line-height:1.8}.failure-callout strong{display:block;margin-bottom:7px}.editor-card{border:1px solid var(--line);border-radius:12px;background:white;padding:24px;margin-top:28px}.editor-card p{font-size:12px;color:var(--muted);margin:10px 0 18px}.json-editor{width:100%;min-height:240px;font:12px/1.7 Consolas,monospace;background:#f8faf5;color:var(--ink);padding:17px;border:1px solid #cbd8c4;border-radius:7px;resize:vertical;tab-size:2}.editor-result{font-size:12px;line-height:1.9;margin-top:18px}.editor-result ul{padding-left:21px;margin:5px 0}.editor-result.success{color:var(--green)}.editor-result.error{color:var(--red)}.teaching-disclaimer{font-size:10px;color:var(--muted);line-height:1.8;margin:18px 0}.lab-prev-next{display:flex;justify-content:space-between;margin-top:25px}.schema-card{background:white;border:1px solid var(--line);border-radius:12px;padding:24px;margin:19px 0;overflow:hidden}.schema-card h2{font-size:20px}.schema-card .source-link{font-size:10px;display:block;margin:7px 0 12px;overflow-wrap:anywhere}.schema-card table{margin-bottom:0}.schema-card code{font-size:10px}.schema-card th:first-child{width:20%}.schema-card th:nth-child(2){width:27%}.reference-body{overflow-wrap:anywhere}.reference-body table{font-size:11px}.reference-body input[type=search]{display:block;width:100%;font:13px system-ui;padding:12px 14px;border:1px solid var(--line);border-radius:7px;margin:15px 0}.reference-body .hidden{display:none}.note-editor{width:100%;min-height:110px;border:1px solid var(--line);border-radius:8px;padding:14px;font-size:12px;line-height:1.8;background:#fff}.note-label{font-size:11px;color:var(--green);font-weight:650;display:block;margin:22px 0 9px}.site-footer{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;border-top:1px solid var(--line);padding:24px 44px;font-size:9px;color:var(--muted);letter-spacing:.4px}.site-footer span:first-child{font-weight:600}.toast{position:fixed;bottom:25px;left:calc(50% + 100px);transform:translate(-50%,20px);padding:12px 18px;border-radius:8px;background:var(--forest);color:white;z-index:60;box-shadow:var(--shadow);font-size:12px;opacity:0;pointer-events:none;transition:opacity .15s,transform .15s}.toast.show{opacity:1;transform:translate(-50%,0)}.no-script{position:fixed;bottom:20px;left:300px;background:white;border:1px solid var(--line);padding:20px;z-index:100}.sidebar-shade{display:none}
@media(min-width:1500px){:root{--rail:280px}.sidebar{padding-inline:22px}main{padding:54px 64px 80px}.topbar{padding-inline:64px}.hero{gap:60px}.hero-visual{min-height:385px}.model-card{margin-top:36px}}
@media(max-width:1150px){:root{--rail:235px}.topbar{padding:0 28px;gap:14px}main{padding:34px 28px 60px}.hero{grid-template-columns:1fr}.hero-visual{min-height:315px;max-width:600px}.hero h1{max-width:720px}.diagram-inputs{margin-top:15px}.model-card{margin-top:20px}.lesson-layout{grid-template-columns:minmax(0,1fr)}.lesson-toc{display:none}.grid-three{grid-template-columns:repeat(2,minmax(0,1fr))}.payload-layout{grid-template-columns:minmax(0,1fr)}.payload-notes{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.payload-notes h3{grid-column:1/-1;margin:0}.annotation{padding-top:12px}.breadcrumb{font-size:9px}.featured-labs{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:800px){.sidebar{transform:translateX(-100%);transition:transform .18s;width:280px}.sidebar.open{transform:translateX(0)}.app-shell{margin-left:0}.sidebar-shade.open{display:block;position:fixed;inset:0;background:#102f2466;z-index:24}.topbar{height:64px;padding:0 20px;gap:13px}.mobile-toggle{display:grid}.breadcrumb{display:none}.search-wrap{width:auto;max-width:none;flex:1;margin-left:0}.search-wrap kbd{display:none}main{padding:30px 24px 50px}.hero{gap:25px;padding-top:0}.hero h1{font-size:43px}.hero .subtext{font-size:14px}.stats{gap:18px;padding:20px 0}.stat strong{font-size:25px}.stat span{font-size:9px}.tracks-grid{gap:14px}.track-card{padding:21px}.section-heading{align-items:start}.section-heading h2{font-size:24px}.toast{left:50%;width:max-content;max-width:90vw}.site-footer{padding:22px 24px}.skip-link{left:20px}.progress-strip{flex-wrap:wrap;gap:15px}.progress-track{width:150px}.lesson-header h1{font-size:37px}.payload-notes{grid-template-columns:1fr}.annotation{padding:12px 0}.lab-panel{padding:21px}.schema-card{padding:20px}.lesson-content table,.reference-body table,.schema-card table{display:block;overflow:auto}.chapter-next{align-items:start}.no-script{left:20px;right:20px}}
@media(max-width:520px){main{padding:26px 18px 45px}.topbar{padding:0 14px;gap:9px}.hero h1{font-size:37px;letter-spacing:-1.5px}.hero-visual{padding:20px;min-height:325px}.diagram-inputs button{padding:10px;font-size:9px}.diagram-inputs{gap:7px}.model-card{padding:20px;margin-top:22px}.tracks-grid,.featured-labs,.grid-three{grid-template-columns:1fr}.stats{grid-template-columns:repeat(2,1fr);gap:16px}.coverage-line{font-size:10px;padding:13px}.section-heading>a{display:none}.subtext{font-size:13px}.page-head h1{font-size:34px}.lesson-header h1{font-size:33px}.lesson-content,.reference-body{font-size:16px;line-height:1.85}.quiz-card{padding:19px}.quiz-option{padding:11px;font-size:11px}.practice-box{padding:20px}.lesson-content h2,.reference-body h2{font-size:23px}.stage-tabs button{padding:10px 7px;font-size:10px;gap:4px}.stage-tabs button span{display:none}.lab-panel{padding:17px;min-height:340px}.lab-toolbar{gap:10px}.lab-prev-next{gap:12px}.lab-prev-next a{font-size:11px}.payload-label{gap:10px}.chapter-next{flex-direction:column;gap:14px}.chapter-next .button{max-width:100%}.search-results{width:calc(100vw - 30px);right:-44px}pre{font-size:11px;padding:17px}.meta-row{gap:10px}.meta-row span+span:before{margin-right:10px}.icon-button{width:32px;height:32px}.site-footer{font-size:8px;padding:20px 18px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important;animation:none!important}}
@media print{.sidebar,.topbar,.site-footer,.lesson-toc,.actions,.chapter-next,.copy-button,.toast,.editor-card,.lab-toolbar,.stage-tabs,.button,.toolbar,.search-wrap{display:none!important}.app-shell{margin:0}main{padding:0;max-width:none}.lesson-layout,.hero,.payload-layout{display:block}body{background:white;font-size:11pt}.lesson-content,.reference-body{font-size:11pt}h1{font-size:26pt}.lesson-header h1{font-size:24pt}pre{background:#f0f3ed;color:#132b27;white-space:pre-wrap;border:1px solid #ccc;break-inside:avoid}.quiz-card,.track-card,.schema-card{break-inside:avoid;box-shadow:none}details>*{display:block}details{break-inside:avoid}.hero-visual{display:none}a{color:#17664c}.source-preview{max-height:none}.hidden{display:table-row!important}}
.sidebar-close{display:none}.practice-count{font-size:15px}.lesson-note a{overflow-wrap:anywhere}
@media(max-width:800px){.sidebar{visibility:hidden}.sidebar.open{visibility:visible}.sidebar-close{display:grid;position:absolute;right:14px;top:18px;background:#2c493f;border-color:#617568;color:white;width:27px;height:27px}.brand{max-width:205px}}