.learn-page{--learn-max:1480px;font-size:16px;line-height:1.7}
.learn-header{display:flex;align-items:center;gap:32px;min-height:96px;padding:20px 48px;border-bottom:1px solid var(--line);max-width:var(--learn-max);margin:auto}
.learn-header .brand img{width:164px}
.learn-header-course{font-size:13px;color:var(--muted)}
.learn-header-app{display:flex;gap:16px;align-items:center;font-size:12px;white-space:nowrap}
.learn-header-app:hover,.learn-header-course:hover{color:var(--accent)}
.learn-header .language-links{margin-left:auto}
.learn-shell{display:grid;grid-template-columns:216px minmax(0,1fr);gap:64px;max-width:var(--learn-max);margin:0 auto;padding:48px}
.course-outline{position:sticky;top:32px;align-self:start;font-size:13px;line-height:1.5}
.course-outline summary{font-weight:500;font-size:13px;cursor:pointer;min-height:44px}
.course-outline nav ol{list-style:none;margin:0;padding:0}
.course-outline nav a{display:grid;grid-template-columns:24px 1fr 12px;gap:12px;padding:16px 0;color:var(--muted);border-bottom:1px solid var(--line);align-items:start;font-size:12px}
.course-outline nav a[aria-current=page]{color:var(--ink);font-weight:600}
.course-outline nav a[aria-current=page] .outline-number{color:var(--accent)}
.course-outline nav a:hover{color:var(--accent)}
.outline-number{font:11px/1.6 var(--mono)}
.outline-state{width:8px;height:8px;margin-top:4px;border:1px solid var(--line);border-radius:50%}
.outline-state.is-complete{background:var(--accent);border-color:var(--accent)}
.outline-progress{display:grid;grid-template-columns:1fr auto;gap:12px;margin-top:32px;font-size:11px;color:var(--muted)}
.outline-progress strong{font:12px var(--mono);color:var(--ink)}
progress{accent-color:var(--accent);display:block;width:100%;height:4px;border:0;background:var(--line);border-radius:0}
progress::-webkit-progress-bar{background:var(--line)}progress::-webkit-progress-value{background:var(--accent)}progress::-moz-progress-bar{background:var(--accent)}
.outline-progress progress{grid-column:1/-1}
.course-outline>.text-link{font-size:11px;margin-top:24px;gap:12px}
.lesson-main{min-width:0;max-width:960px;margin:0;width:100%}
.lesson-title{padding:0 0 48px;border-bottom:1px solid var(--line)}
.lesson-breadcrumb{font-size:12px;color:var(--muted);display:inline-flex;min-height:44px;align-items:center;margin-bottom:24px}
.lesson-breadcrumb:hover{color:var(--accent)}
.lesson-meta{display:flex;justify-content:space-between;gap:24px;color:var(--muted);font-size:10px}
.lesson-title h1{font-size:clamp(48px,5.2vw,80px);line-height:1.02;margin:24px 0;max-width:800px;overflow-wrap:break-word}
.lesson-summary{font-size:18px;line-height:1.7;max-width:680px;color:var(--muted)}
.lesson-objectives{display:grid;grid-template-columns:160px 1fr;gap:24px;margin-top:40px;max-width:760px}
.lesson-objectives h2{font:500 14px/1.6 var(--body);letter-spacing:0}
.lesson-objectives ul{padding:0 0 0 16px;margin:0;font-size:14px;color:var(--muted)}
.lesson-objectives li{padding-left:4px;margin-bottom:8px}
.lesson-objectives li::marker{color:var(--accent)}
.lesson-explanations{max-width:760px}
.explanation-section{margin-top:48px}
.explanation-section h2,.worked-example h2,.lesson-checks>h2,.lesson-sources h2{font-size:32px;line-height:1.14;letter-spacing:-.015em;margin-bottom:20px}
.explanation-section>p{font-size:16px;line-height:1.8;margin-top:16px}
.explanation-section>p.lesson-key-point{margin-top:24px;border-left:3px solid var(--accent);padding:4px 0 4px 20px;color:var(--muted);font-size:15px}
.lesson-formula{font:14px/1.8 var(--mono);padding:20px 24px;background:var(--surface);margin-top:24px;border-radius:4px;overflow-wrap:anywhere;white-space:pre-wrap}
.lesson-lab{background:var(--surface);padding:32px;margin-top:56px;border-radius:var(--radius);min-width:0}
.learn-section-top{display:flex;justify-content:space-between;align-items:start;gap:24px;margin-bottom:24px}
.learn-section-top>.mono:last-child{font-size:10px;color:var(--muted);max-width:300px;text-align:right}
.lesson-lab>h2{font-size:36px;line-height:1.1;margin-bottom:16px}
.lab-intro{font-size:15px;line-height:1.75;max-width:700px}
.lesson-conditions{font:11px/1.8 var(--mono);margin-top:24px;color:var(--muted);overflow-wrap:anywhere}
.lab-workspace{display:grid;grid-template-columns:minmax(0,1fr) 192px;gap:32px;margin-top:24px}
.lab-visual{min-width:0;background:var(--paper);padding:16px;border-radius:4px;align-self:start}
.lesson-diagram{display:block;width:100%;height:auto;overflow:hidden}
.lesson-compass{font:11px var(--mono);fill:var(--muted);text-anchor:middle}
.desired-line{stroke:var(--accent);stroke-width:1.5;stroke-dasharray:6 6;fill:none;opacity:.45}
.air-vector{stroke:var(--ink);stroke-width:1.8;stroke-dasharray:5 4;fill:none}
.ground-vector{stroke:var(--accent);stroke-width:2.2;fill:none}
.wind-vector{stroke:var(--muted);stroke-width:1.4;fill:none}
.lab-readouts{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;padding:16px 0;border-top:1px solid var(--line)}
.lab-readouts>div{min-width:0;display:flex;flex-direction:column;gap:8px}
.lab-readouts span{font-size:11px;line-height:1.5;color:var(--muted);min-height:32px;overflow-wrap:break-word}
.lab-readouts output{font:400 21px/1.3 var(--mono);white-space:nowrap;color:var(--ink)}
.lab-readouts>div:nth-child(2) output{color:var(--accent)}
.vector-legend{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:10px;line-height:1.6;color:var(--muted);padding-top:12px;border-top:1px solid var(--line)}
.vector-legend>span{display:inline-flex;align-items:center;gap:6px}
.vector-legend>span::before{content:'';display:block;width:14px;height:2px;background:var(--ink)}
.vector-legend>.legend-ground::before{background:var(--accent)}
.vector-legend>.legend-wind::before{background:var(--muted)}
.lab-inputs{min-width:0}
.lab-control{display:grid;grid-template-columns:1fr auto;column-gap:8px;row-gap:8px;margin-bottom:24px;align-items:center}
.lab-control>label{font-size:12px;line-height:1.6}
.lab-number{display:flex;align-items:center;gap:6px;font:12px var(--mono)}
.lab-number input{width:64px;min-height:44px;border:1px solid var(--ui-control-border,#838A7C);border-radius:4px;background:var(--paper);font:13px var(--mono);padding:8px;color:var(--ink)}
.lab-control>input[type=range]{grid-column:1/-1;margin:0;height:44px;width:100%}
.input-help{font-size:11px;color:var(--muted);line-height:1.7;margin:8px 0 16px}
.quiet-action{min-height:44px;padding:8px 0;background:none;border:0;border-bottom:1px solid #a6ae9d;font-size:12px;text-align:left}
.quiet-action:hover{color:var(--accent)}
.lab-task{border-top:1px solid #C6CCBD;margin-top:32px;padding-top:24px}
.lab-task h3{font:550 26px/1.3 var(--display);letter-spacing:-.01em;margin-top:12px;max-width:760px}
.lab-hint{font-size:13px;margin:20px 0;max-width:700px;color:var(--muted)}
.lab-hint>summary{min-height:44px;cursor:pointer;display:list-item;list-style-position:inside}
.lab-hint p{line-height:1.8;padding:12px 0}
.lab-task>.button{min-width:224px;max-width:360px;font-size:13px}
.task-feedback{margin-top:16px;font-size:13px;line-height:1.8;min-height:48px;max-width:760px}
.task-feedback.is-correct{color:#246442}
.task-feedback.is-wrong{color:#943E2E}
.vor-lesson-figures{display:grid;grid-template-columns:minmax(0,1fr) 140px;align-items:center;gap:12px;min-height:280px}
.vor-indicator{display:block;width:100%;height:auto}
.vor-map-ring{stroke:#9BA58F;stroke-width:1;fill:none;stroke-dasharray:3 5}
.vor-map-axis{stroke:var(--line);stroke-width:1;fill:none}
.station-label{font:11px var(--mono);text-anchor:middle;fill:var(--muted)}
.worked-example{max-width:760px;margin-top:56px;padding:32px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.worked-example h2{margin-top:20px}
.worked-example ol{padding-left:24px;margin:0}
.worked-example li{font-size:15px;line-height:1.8;padding-left:8px;margin:16px 0}
.worked-example li::marker{color:var(--accent);font:13px var(--mono)}
.worked-result{font:550 24px/1.4 var(--display);padding-top:16px;max-width:700px}
.lesson-checks{margin-top:56px;max-width:760px}
.lesson-checks>h2{font-size:40px;margin-top:20px;margin-bottom:32px}
.knowledge-check{padding:32px 0;margin:0;border-top:1px solid var(--line)}
.knowledge-check fieldset{border:0;margin:0;padding:0;min-width:0}
.knowledge-check legend{padding:0;width:100%;font:550 25px/1.4 var(--display);letter-spacing:-.01em}
.question-number{display:block;color:var(--muted);font-size:10px;margin-bottom:12px;letter-spacing:.06em}
.check-fields{display:grid;gap:8px;margin-top:20px}
.lesson-option{display:flex;align-items:flex-start;gap:12px;padding:14px 16px;border:1px solid var(--line);border-radius:4px;font-size:14px;line-height:1.7;min-height:56px;cursor:pointer}
.lesson-option:hover{background:var(--surface)}
.lesson-option:has(input:checked){background:var(--surface);border-color:var(--muted)}
.lesson-option input{width:18px;height:18px;margin:3px 0;flex-shrink:0;accent-color:var(--accent)}
.answer-number{display:inline-flex;align-items:center;gap:12px;justify-self:start;font:14px var(--mono)}
.answer-number input{width:136px;min-height:52px;padding:12px 16px;background:var(--white);border:1px solid var(--muted);border-radius:4px;font:18px var(--mono);color:var(--ink)}
.check-button{display:inline-flex;align-items:center;gap:24px;min-height:44px;padding:12px 0;margin-top:16px;background:none;border:0;border-bottom:1px solid var(--muted);font-size:12px}
.check-button:hover{color:var(--accent);border-color:var(--accent)}
.answer-feedback{font-size:14px;line-height:1.8;margin-top:16px;max-width:680px}
.answer-feedback:empty{display:none}
.answer-feedback strong{display:block;font-weight:600;margin-bottom:4px;color:var(--accent)}
.answer-feedback.is-correct strong{color:#246442}
.lesson-takeaways{max-width:760px;border-top:1px solid var(--line);padding-top:32px;margin-top:24px}
.lesson-takeaways ul{list-style:none;padding:0;margin:20px 0}
.lesson-takeaways li{font:500 24px/1.4 var(--display);margin-top:16px;display:flex;gap:16px}
.lesson-takeaways li::before{content:'↗';color:var(--accent);flex-shrink:0}
.lesson-completion{display:flex;gap:32px;align-items:flex-end;justify-content:space-between;background:var(--graphite);color:var(--paper);border-radius:var(--radius);padding:32px;margin-top:48px}
.lesson-completion .section-label{color:#B6BCAE}
.lesson-completion h2{font-size:36px;margin:16px 0}
.lesson-completion p{font-size:13px;line-height:1.8;color:#B6BCAE;max-width:460px}
.lesson-completion p.completion-count{font-size:11px;margin:16px 0}
.lesson-completion button.primary{background:#FFAD8E;color:var(--ink);width:100%;max-width:320px}
.lesson-completion button:disabled{background:#444E41;opacity:.7;color:#CAD0C2;cursor:not-allowed;transform:none}
.lesson-completion>.button{background:none;color:var(--paper);border-bottom:1px solid #62665D;border-radius:0;clip-path:none;padding-left:0;padding-right:0;max-width:280px;font-size:12px;line-height:1.6}
.lesson-completion.is-complete{background:#26352A}
.save-note{display:block;font-size:10px;color:#B6BCAE;margin-top:12px}
.lesson-sources{max-width:760px;margin-top:48px}
.lesson-sources h2{font-size:26px}
.lesson-sources>p{font-size:12px;line-height:1.8;color:var(--muted)}
.lesson-sources ul{list-style:none;margin:20px 0;padding:0}
.lesson-sources li{padding:12px 0;font-size:12px;line-height:1.7;overflow-wrap:anywhere}
.lesson-sources a{text-decoration:underline;text-underline-offset:4px}
.lesson-sources li>span{display:block;color:var(--muted);margin-top:6px}
.lesson-sources .model-limitation{margin:20px 0}
.lesson-sources .mono{font-size:10px}
.lesson-bottom-links{display:flex;align-items:center;justify-content:space-between;gap:20px;border-top:1px solid var(--line);padding-top:24px;margin-top:32px}
.lesson-bottom-links a,.lesson-bottom-links button{font:12px var(--body);color:var(--muted);background:none;border:0;padding:12px 0;min-height:44px}
.lesson-bottom-links a:hover,.lesson-bottom-links button:hover{color:var(--accent)}
.learning-save-warning{max-width:var(--learn-max);margin:16px auto;padding:16px 48px;color:#943E2E;background:#F9E8E3;font-size:13px;line-height:1.7}
.learn-footer{max-width:var(--learn-max);margin:auto;padding:32px 48px;border-top:1px solid var(--line);display:flex;align-items:center;flex-wrap:wrap;gap:24px;font-size:11px;color:var(--muted)}
.learn-footer>nav{margin-left:auto;display:flex;gap:24px;flex-wrap:wrap}
.learn-footer a:hover{color:var(--accent)}
.learn-footer>.mono{font-size:9px}
.course-index{max-width:var(--learn-max);margin:0 auto;padding:64px 48px}
.course-intro{display:grid;grid-template-columns:1.5fr 1fr;gap:96px;align-items:end}
.course-intro h1{font-size:clamp(72px,7.5vw,112px);margin:32px 0;line-height:.98}
.course-intro>div>p{font-size:17px;line-height:1.8;color:var(--muted);max-width:560px}
.course-progress-panel{background:var(--surface);padding:32px;border-radius:var(--radius)}
.course-progress-panel>strong{font:550 56px/1.2 var(--display);display:block;margin:20px 0}
.course-progress-panel>p{font-size:12px!important;line-height:1.8;margin-top:20px}
.course-progress-panel>.button{margin-top:24px}
.course-lessons{margin-top:72px}
.course-section-label{display:flex;align-items:center;justify-content:space-between;gap:24px;color:var(--muted);margin-bottom:24px}
.course-lessons>ol{list-style:none;padding:0;margin:0}
.lesson-row{display:grid;grid-template-columns:48px minmax(0,1fr) 180px;gap:32px;align-items:center;padding:32px 0;border-top:1px solid var(--line)}
.lesson-row:hover h2{color:var(--accent)}
.lesson-row-number{color:var(--accent);align-self:start;padding-top:4px}
.lesson-row h2{font:550 36px/1.15 var(--display);margin:12px 0;letter-spacing:-.02em}
.lesson-row p{font-size:13px;line-height:1.8;color:var(--muted);max-width:620px}
.lesson-row-state{display:flex;justify-content:space-between;align-items:center;gap:24px;font-size:12px}
.lesson-row-state.is-complete{color:#246442}
.course-note{display:flex;justify-content:space-between;gap:48px;align-items:center;border-top:1px solid var(--line);padding-top:32px;font-size:12px;color:var(--muted)}
.course-note>.text-link{max-width:360px;flex-shrink:0}
@media(max-width:1100px){.learn-shell{grid-template-columns:184px minmax(0,1fr);gap:32px;padding:40px 32px}.learn-header{padding:20px 32px;gap:24px}.lab-workspace{grid-template-columns:minmax(0,1fr);gap:24px}.lab-inputs{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px 24px}.lab-control{margin-bottom:0}.input-help{margin:0}.quiet-action{align-self:start}.vor-lesson-figures{grid-template-columns:minmax(0,1fr) 180px;min-height:260px}.lesson-completion{flex-direction:column;align-items:stretch}.lesson-completion>.button{max-width:100%}.course-intro{gap:48px}.course-index{padding:48px 32px}.learn-footer{padding:32px}.lesson-row{grid-template-columns:32px minmax(0,1fr) 144px;gap:24px}.lesson-row h2{font-size:32px}}
@media(max-width:800px){.learn-header{padding:16px 24px;gap:16px;min-height:80px}.learn-header .brand img{width:136px}.learn-header-course{display:none}.learn-header-app{font-size:10px;gap:8px}.learn-header-app>.arrow{display:none}.learn-shell{grid-template-columns:minmax(0,1fr);gap:32px;padding:24px}.course-outline{position:static;border-bottom:1px solid var(--line);padding-bottom:16px}.course-outline summary{min-height:32px;font-size:12px}.course-outline nav ol{display:grid;grid-template-columns:1fr 1fr;gap:0 24px}.course-outline nav a{font-size:11px;gap:8px;grid-template-columns:20px 1fr 10px;padding:12px 0}.outline-progress,.course-outline>.text-link{display:none}.lesson-breadcrumb{margin-bottom:12px}.lesson-meta{font-size:9px;gap:12px;flex-wrap:wrap}.lesson-title h1{font-size:48px;margin:24px 0}.lesson-summary{font-size:16px}.lesson-objectives{grid-template-columns:1fr;gap:12px;margin-top:28px}.lesson-objectives ul{font-size:13px}.lesson-title{padding-bottom:32px}.explanation-section{margin-top:32px}.explanation-section h2{font-size:29px}.explanation-section>p{font-size:15px;line-height:1.85}.explanation-section>p.lesson-key-point{font-size:14px;padding-left:16px}.lesson-formula{font-size:12px;padding:16px;line-height:1.9}.lesson-lab{padding:20px;margin:40px -8px 0}.learn-section-top{flex-direction:column;gap:12px;margin-bottom:20px}.learn-section-top>.mono:last-child{text-align:left;max-width:100%;font-size:10px}.lesson-lab>h2{font-size:31px}.lab-intro{font-size:14px}.lesson-conditions{font-size:10px;margin-top:20px}.lab-workspace{gap:24px;margin-top:20px}.lab-visual{padding:12px}.lab-readouts{gap:12px}.lab-readouts span{font-size:10px;min-height:36px}.lab-readouts output{font-size:19px}.vector-legend{font-size:9px;gap:8px 12px}.lab-inputs{grid-template-columns:1fr;gap:16px}.lab-control{grid-template-columns:1fr auto;row-gap:4px}.lab-control>label{font-size:13px}.lab-number input{width:76px;font-size:14px}.lab-control>input[type=range]{height:44px}.input-help{font-size:11px}.quiet-action{justify-self:start}.lab-task{margin-top:24px;padding-top:20px}.lab-task h3{font-size:24px;line-height:1.35}.lab-task>.button{min-width:0;width:100%;max-width:100%;font-size:12px}.lab-hint{font-size:12px;margin:16px 0}.task-feedback{font-size:13px;min-height:0;line-height:1.8}.vor-lesson-figures{grid-template-columns:minmax(0,1fr) 120px;gap:4px;min-height:220px}.worked-example{margin-top:40px;padding:24px 0}.worked-example h2{font-size:29px}.worked-example li{font-size:14px;padding-left:4px}.worked-result{font-size:23px}.lesson-checks{margin-top:40px}.lesson-checks>h2{font-size:34px}.knowledge-check{padding:24px 0}.knowledge-check legend{font-size:24px}.lesson-option{font-size:14px;padding:12px;gap:12px}.check-button{font-size:12px;min-height:48px}.answer-feedback{font-size:13px}.lesson-takeaways li{font-size:22px;gap:12px}.lesson-completion{padding:24px;margin:32px -8px 0;gap:24px}.lesson-completion h2{font-size:31px}.lesson-completion p{font-size:12px}.lesson-completion>.button{font-size:12px}.lesson-sources{margin-top:32px}.lesson-sources h2{font-size:26px}.lesson-sources>p,.lesson-sources li{font-size:12px}.lesson-bottom-links{gap:16px}.lesson-bottom-links a,.lesson-bottom-links button{font-size:11px}.learn-footer{padding:24px;gap:20px}.learn-footer>nav{margin-left:0;gap:16px;font-size:10px}.learn-footer>.mono{width:100%}.course-index{padding:40px 24px}.course-intro{grid-template-columns:1fr;gap:32px}.course-intro h1{font-size:72px;margin:24px 0}.course-intro>div>p{font-size:15px}.course-progress-panel{padding:24px}.course-progress-panel>strong{font-size:44px;margin:16px 0}.course-lessons{margin-top:48px}.course-section-label{font-size:9px;gap:16px}.course-section-label>.section-label{font-size:9px}.lesson-row{grid-template-columns:24px minmax(0,1fr);gap:16px;padding:24px 0}.lesson-row h2{font-size:30px;margin:12px 0}.lesson-row p{font-size:13px}.lesson-row-state{grid-column:2;font-size:12px;justify-content:flex-start;gap:16px}.lesson-row .section-label{font-size:9px}.course-note{flex-direction:column;align-items:stretch;gap:24px;padding-top:24px}.course-note>.text-link{max-width:100%}.learning-save-warning{margin:12px 24px;padding:16px;font-size:12px}}
@media(max-width:420px){.learn-header{gap:12px;padding-left:20px;padding-right:20px}.learn-header .brand img{width:120px}.learn-header .language-links{gap:2px}.learn-header .language-links>a{min-width:24px}.learn-header-app{font-size:9px;white-space:normal;max-width:92px;line-height:1.6}.lesson-title h1{font-size:44px}.vor-lesson-figures{grid-template-columns:minmax(0,1fr);gap:12px}.vor-lesson-figures>.lesson-diagram{max-width:280px;margin:auto}.vor-indicator{width:168px;justify-self:center;margin-bottom:12px}}
@media(prefers-reduced-motion:reduce){.learn-page{scroll-behavior:auto}}
.learn-header .language-links>a{min-width:44px;min-height:44px}
@media(max-width:420px){.learn-header-app{display:none}.learn-header .language-links>a{min-width:44px}}
.course-outline summary{min-height:44px}