.learn-page .page-content{max-width:1180px}.learn-overview,.learn-module,.learn-not-found,.lesson{max-width:1000px;margin:auto;padding:clamp(20px,4vw,52px);border:1px solid var(--line);border-radius:var(--app-shell-radius);background:#fff}.learn-overview h2,.learn-module h2,.learn-not-found h2,.lesson h2{margin:0;letter-spacing:-.04em;font-size:clamp(34px,5vw,62px);line-height:1}.learn-lead{max-width:700px;font-size:19px;line-height:1.55;color:#465267}.learn-module-card{display:flex;align-items:end;justify-content:space-between;gap:30px;margin-top:32px;padding:28px;border:1px solid var(--academy-lime-border);border-radius:15px;background:linear-gradient(140deg,var(--academy-lime-soft),#fff 62%)}.learn-module-card h3{margin:0;font-size:28px}.learn-availability,.lesson-meta{color:#526174;font-size:13px;font-weight:700}.lesson-list{display:grid;gap:8px;padding:0;list-style:none}.lesson-list__item{display:grid;grid-template-columns:42px minmax(0,1fr) 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a{color:#405700}.lesson-objectives,.lesson-callout,.worked-example,.lesson-synthesis,.lesson-completion,.lesson-references{margin:26px 0;padding:18px 20px;border-radius:10px}.lesson-objectives{background:#f8ffdf;border-left:4px solid var(--academy-lime)}.lesson-callout{border:1px solid #eee37f;background:#fffde0}.lesson-callout p{margin:6px 0 0}.lesson h3{margin:42px 0 15px;font-size:clamp(25px,3vw,34px);letter-spacing:-.025em}.lesson p,.lesson li{font-size:18px;line-height:1.68}.lesson code{padding:2px 5px;border-radius:4px;background:#f1f4f7;color:#263244;font-size:.9em;white-space:normal}.worked-example{border:1px solid #dff58b;background:#fdfff7}.worked-example p{margin-bottom:0}.wave-lab,.anatomy{margin:28px 0;padding:18px;border:1px solid var(--line);border-radius:12px;background:#fafbfd}.wave-lab__controls,.anatomy__buttons{display:flex;flex-wrap:wrap;gap:9px;align-items:center}.wave-lab button,.anatomy button,.quiz button{min-height:38px;padding:7px 12px;border:1px solid #b7c0cc;border-radius:7px;background:white;color:#263244;font:inherit;font-weight:700;cursor:pointer}.wave-lab input{accent-color:#7a9d00}.wave-lab svg,.anatomy svg{display:block;width:100%;height:auto;margin-top:15px;overflow:visible}.wave-lab line{stroke:#cbd5e1;stroke-width:1}.wave-lab circle{fill:#64748b}.wave-lab circle.is-focus{fill:#6a8600;stroke:#172000;stroke-width:2}.anatomy__buttons button[aria-pressed="true"]{border-color:#b2df18;background:#c9ff20}.anatomy [data-part-geometry]{fill:#d6dce5;stroke:#344054;stroke-width:3;transition:fill .15s}.anatomy [data-part-geometry].is-selected{fill:#c9ff20;stroke:#405700;stroke-width:5}.anatomy-axis{stroke:#ef476f;stroke-dasharray:7 5;stroke-width:2}.lesson-caption{margin-top:-18px;font-size:13px!important;color:#64748b}.quiz{display:grid;gap:18px}.quiz fieldset{display:grid;gap:9px;margin:0;padding:17px;border:1px solid var(--line);border-radius:10px}.quiz legend{padding:0 4px;font-weight:800}.quiz 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[data-part-geometry]{transition:none}}@media(max-width:600px){.learn-overview,.learn-module,.learn-not-found,.lesson{padding:20px;border-radius:12px}.learn-module-card{align-items:start;flex-direction:column;padding:20px}.lesson-list__item{grid-template-columns:32px minmax(0,1fr)}.lesson-list__item a,.lesson-planned{grid-column:2}.wave-lab,.anatomy{padding:12px}.lesson p,.lesson li{font-size:17px}}@media print{.learn-mode-switch,.site-header,.wave-lab__controls,.anatomy__buttons,.lesson-completion{display:none!important}.lesson{border:0;padding:0}.wave-lab,.anatomy{break-inside:avoid}}

/* Reference lesson: readable equations and a real motor-section close-up. */
.lesson-equation { margin: 18px 0; padding: 16px; background: #f5f7fa; border-radius: 8px; overflow-wrap: anywhere; }
.lesson code { overflow-wrap: anywhere; }
.lesson details:not(.lesson-contents) { margin: 20px 0; padding: 14px 16px; border: 1px solid var(--line); border-radius: 9px; }
.lesson details summary { cursor: pointer; font-weight: 750; line-height: 1.5; }
.lesson details summary:focus-visible { outline: 3px solid #405700; outline-offset: 3px; }
.lesson .glossary { display: grid; grid-template-columns: minmax(130px, 0.7fr) minmax(0, 2fr); gap: 12px 18px; }
.lesson .glossary dt { font-weight: 750; }
.lesson .glossary dd { margin: 0; line-height: 1.6; }
.anatomy [data-part-geometry] { stroke-width: 1.1; }
.anatomy [data-part-geometry="gap"] { fill: #fff; }
.anatomy [data-part-geometry].is-selected { fill: #c9ff20; stroke-width: 1.6; }
.anatomy .anatomy-outline { fill: none; }
.anatomy .anatomy-outward { stroke: #405700; stroke-width: 2; }
.anatomy .anatomy-label { font: 16px sans-serif; fill: #465267; }
.anatomy .anatomy-motor-inset { margin-bottom: 0; background: #fff; }
.anatomy .anatomy-detail-svg { width: min(100%, 290px); max-height: 250px; margin: 16px auto; overflow: hidden; }
.anatomy .anatomy-detail-caption { font-size: 14px; line-height: 1.6; margin-bottom: 0; }
.anatomy-legend { display: grid; gap: 8px; font-size: 14px!important; }
.wave-lab .lesson-caption { margin-top: 12px; }
.wave-lab button:disabled { cursor: default; opacity: 0.65; }
.lesson-references li { overflow-wrap: anywhere; }
@media (max-width: 600px) {
  .lesson .glossary { grid-template-columns: 1fr; gap: 5px; }
  .lesson .glossary dd { margin-bottom: 12px; }
  .anatomy .anatomy-label { font-size: 20px; }
}

.lesson section[id] { scroll-margin-top: 110px; }

/* 01.01 is a deck: one generous teaching stage, not a condensed article. */
.learn-page .lesson-deck{max-width:1180px;min-height:0;padding:clamp(18px,2.5vw,34px);background:linear-gradient(135deg,#fff 0%,#fbfdf6 100%)}
.lesson-deck .deck-header{display:flex;align-items:center;gap:16px;padding-bottom:14px;border-bottom:1px solid var(--line);color:#526174;font-size:14px;font-weight:750}.lesson-deck .learn-breadcrumb{margin:0}.deck-restart{margin-left:auto;border:0;background:transparent;color:#526174;font:inherit;text-decoration:underline;cursor:pointer}.deck-stage{display:grid;grid-template-columns:minmax(280px,.75fr) minmax(420px,1.25fr);align-items:center;gap:clamp(28px,5vw,76px);min-height:590px;padding:22px 4px;outline:none}.deck-card__copy h2{margin:0 0 18px;font-size:clamp(38px,4.2vw,64px);line-height:.98;letter-spacing:-.055em}.deck-card__copy>p{margin:0;color:#425166;font-size:clamp(18px,1.5vw,21px);line-height:1.55}.deck-card__visual{min-width:0}.deck-driver-silhouette{display:block;width:100%;max-height:410px}.deck-navigation{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--line);padding-top:16px}.deck-navigation button,.deck-navigation select,.signal-chain button,.air-wave button,.pressure-lab button,.deck-quiz button{min-height:42px;border:1px solid #b7c0cc;border-radius:8px;background:#fff;color:#263244;padding:8px 15px;font:inherit;font-weight:750;cursor:pointer}.deck-navigation button:disabled,.signal-chain button:disabled{cursor:default;opacity:.45}.deck-navigation label{color:#526174;font-size:14px;font-weight:700}.deck-navigation select{min-height:36px;margin-left:5px;padding:4px 8px}.deck-details{grid-column:1/-1;margin-top:16px;padding:12px 14px;border:1px solid var(--line);border-radius:9px;background:#fafbfd;color:#465267}.deck-details summary{cursor:pointer;font-weight:750}.deck-details p,.deck-details li{font-size:14px;line-height:1.5}.deck-version{margin:10px 0 0;color:#718096;font-size:12px}.signal-chain{padding:28px;border:1px solid #dce6c0;border-radius:18px;background:radial-gradient(circle at top right,#efffc3,#fff 62%)}.signal-chain ol{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;padding:0;margin:0 0 24px;list-style:none}.signal-chain li{display:grid;gap:7px;justify-items:center;color:#718096;font-size:13px;font-weight:750;text-align:center}.signal-chain b{display:grid;width:42px;height:42px;place-items:center;border:2px solid #cbd5e1;border-radius:999px;background:#fff}.signal-chain .is-active{color:#405700}.signal-chain .is-active b{border-color:#9bc900;background:#caff20}.signal-chain p,.air-wave p,.pressure-lab p{min-height:3em;color:#465267;font-size:16px;line-height:1.45}.air-wave,.pressure-lab{padding:28px;border:1px solid var(--line);border-radius:18px;background:#fff}.air-wave__row{display:flex;align-items:center;justify-content:space-between;height:190px;padding:0 20px;border-bottom:2px solid #dbe4ea}.air-wave__row i{width:16px;height:16px;border-radius:50%;background:#526174;transform:translateX(calc(sin(var(--n)) * 4px));transition:transform .2s}.air-wave[data-tracking="true"] .air-wave__row i:nth-child(6){outline:7px solid #caff20;outline-offset:4px}.air-wave__legend{display:flex;justify-content:space-between;gap:16px;margin:14px 0;color:#526174;font-size:13px}.pressure-gauge{position:relative;height:180px;border-left:3px solid #344255;background:linear-gradient(to bottom,#e5f8af 0 32%,#f7fafc 32% 68%,#dbeafe 68%)}.pressure-gauge:before,.pressure-gauge:after{position:absolute;left:14px;color:#526174;font-size:13px;font-weight:700}.pressure-gauge:before{content:'above equilibrium';top:14px}.pressure-gauge:after{content:'below equilibrium';bottom:14px}.pressure-gauge span{position:absolute;left:52%;top:calc(50% - 12px);font-weight:800}.pressure-gauge i{position:absolute;left:-10px;top:50%;width:20px;height:20px;border-radius:50%;background:#caff20;border:2px solid #405700;transition:top .2s}.pressure-lab[data-pressure="above"] .pressure-gauge i{top:22%}.pressure-lab[data-pressure="below"] .pressure-gauge i{top:78%}.pressure-lab__buttons{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}.deck-quiz{padding:24px;border:1px solid #dce6c0;border-radius:18px;background:#fff}.deck-quiz__count{margin:0 0 8px;color:#526174;font-size:13px;font-weight:800}.deck-quiz h3{margin:0 0 18px;font-size:clamp(22px,2vw,30px);line-height:1.15}.deck-quiz [role="radiogroup"]{display:grid;gap:9px;margin-bottom:18px}.deck-quiz label{padding:10px 12px;border:1px solid var(--line);border-radius:8px;font-size:16px;line-height:1.4}.deck-quiz input{accent-color:#7a9d00}.deck-quiz__feedback{min-height:3em;margin:14px 0 0;font-size:15px;font-weight:750;line-height:1.45}.deck-quiz__feedback.is-correct{color:#405700}.deck-quiz__feedback.is-incorrect{color:#9b2140}.deck-completion{margin-top:18px;padding:14px;border-left:4px solid #caff20;background:#f8ffdf}.deck-completion label{font-weight:800}.deck-completion p{margin:8px 0 0;color:#526174;font-size:13px;line-height:1.4}.lesson-deck button:focus-visible,.lesson-deck select:focus-visible,.lesson-deck input:focus-visible,.lesson-deck summary:focus-visible{outline:3px solid #405700;outline-offset:3px}
@media(max-width:760px){.deck-stage{grid-template-columns:1fr;gap:22px;min-height:0;padding:22px 0}.deck-card__copy h2{font-size:clamp(37px,12vw,53px)}.deck-card__visual{order:-1}.deck-driver-silhouette{max-height:260px}.lesson-deck .deck-header{gap:10px;flex-wrap:wrap}.deck-restart{margin-left:0}.air-wave,.pressure-lab,.signal-chain,.deck-quiz{padding:18px}.air-wave__row{height:135px;padding:0 8px}.air-wave__row i{width:12px;height:12px}.air-wave__legend{display:grid}.deck-navigation label{display:none}}
@media(prefers-reduced-motion:reduce){.air-wave__row i,.pressure-gauge i{transition:none}}

/* Deck interaction refinements: the air model is a real parcel view, not CSS decoration. */
.deck-takeaway{font-weight:650}.air-wave svg{display:block;width:100%;height:auto;border-bottom:2px solid #dbe4ea}.air-wave line{stroke:#cbd5e1;stroke-width:2}.air-wave circle{fill:#526174}.air-wave circle.is-focus{fill:#caff20;stroke:#405700;stroke-width:3}.air-wave__controls,.deck-quiz__actions{display:flex;flex-wrap:wrap;gap:8px;align-items:center}.air-wave__controls label{font-size:14px;font-weight:700}.air-wave__controls input{vertical-align:middle;accent-color:#7a9d00}.deck-quiz__actions{margin-top:4px}.pressure-lab__buttons button[aria-pressed="true"]{border-color:#9bc900;background:#efffc3}

/* Focused lesson workspace; the Library and Learn overview are untouched. */
.learn-page:has(.lesson-deck) .page-heading { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip-path:inset(50%); white-space:nowrap; }
.learn-page .lesson-deck { max-width:1320px; padding:20px 28px; margin-top:12px; }
.lesson-deck .deck-stage { min-height:480px; grid-template-columns:minmax(230px,.6fr) minmax(0,1.4fr); gap:34px; padding:16px 0; }
.lesson-deck .deck-card__copy h2 { font-size:clamp(32px,3.5vw,48px); line-height:1.05; outline:none; }
.lesson-deck .deck-card__copy h2:focus-visible { box-shadow:-4px 0 0 #a1c918; padding-left:12px; }
.lesson-deck .deck-card__copy>p { font-size:18px; font-weight:500; line-height:1.55; }
.lesson-deck .deck-navigation { padding-top:12px; }
.lesson-deck .deck-navigation .button--primary { background:#c9ff20; border-color:#acd900; color:#1d2b00; }
.lesson-deck>details.deck-details { margin:12px 0 0; padding:8px 12px; }
.lesson-deck .deck-version { font-size:11px; line-height:1.3; margin:5px 0 0; }
.lesson-deck .learn-breadcrumb { color:#455e00; }
.lesson-deck .driver-explorer .de-svg { height:228px; }
.lesson-deck .driver-explorer[data-explorer-mode="intro"] .de-svg { height:320px; }
.lesson-deck .motion-lab,.lesson-deck .relationship-map{padding:20px;border:1px solid var(--line);border-radius:18px;background:#fff}.motion-lab svg,.relationship-map svg{display:block;width:100%;height:auto}.motion-fixed{fill:#91a0a9;stroke:#445563;stroke-width:3}.motion-cone{fill:#50616a;stroke:#263745;stroke-width:3}.motion-coil{fill:#d78c45;stroke:#92531d;stroke-width:3}.motion-cap{fill:#35454e}.motion-lab [data-motion-surround],.motion-lab [data-motion-spider]{fill:none;stroke:#a77c37;stroke-width:9;stroke-linecap:round}.motion-axis{stroke:#aab8c4;stroke-dasharray:7 7;stroke-width:2}.motion-lab text{fill:#405164;font:14px system-ui}.motion-lab__controls{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.motion-lab__controls label{font-size:14px;font-weight:750}.motion-lab input{accent-color:#7a9d00}.motion-lab__controls button,.relationship-map button{min-height:40px;border:1px solid #b7c0cc;border-radius:8px;background:#fff;color:#263244;padding:8px 14px;font:inherit;font-weight:750;cursor:pointer}.motion-lab p,.relationship-map p{margin:13px 0 0;color:#465267;font-size:15px;line-height:1.45}.relationship-map .rel-link{fill:none;stroke:#b3c23b;stroke-width:6;stroke-linecap:round}.relationship-map [data-rel-node]>*{fill:#f8fafc;stroke:#607384;stroke-width:3}.relationship-map [data-rel-node] text{fill:#273a49;stroke:none;font:700 15px system-ui;text-anchor:middle}.relationship-map__controls{display:flex;gap:7px;flex-wrap:wrap;margin-top:8px}.relationship-map button[aria-pressed=true],.signal-chain button[aria-pressed=true]{background:#e8f9a6;border-color:#9bc900;color:#2d4200}.signal-chain ol button{display:grid;gap:7px;justify-items:center;width:100%;min-height:78px;padding:5px;border:1px solid transparent;border-radius:10px;background:transparent;color:inherit;font:inherit;cursor:pointer}.signal-chain ol button:focus-visible,.relationship-map button:focus-visible,.motion-lab button:focus-visible{outline:3px solid #405700;outline-offset:2px}.chain-support{margin-top:12px;padding:12px;border-radius:10px;background:#f4f7f9;color:#425166;font-size:14px;line-height:1.45}.chain-support p{min-height:0;margin:7px 0 0;font-size:13px}.air-wave .air-driver{fill:#8a9aa5;stroke:#40515e;stroke-width:3}.air-wave [data-air-cone]{fill:#52636d;stroke:#263745;stroke-width:3;transform-box:fill-box;transform-origin:center;transition:transform .1s linear}.air-wave text{font:700 14px system-ui;fill:#425466}.pressure-scene{display:grid;grid-template-columns:1fr 1.7fr 1fr;align-items:center;gap:8px;padding:12px;border:1px solid #e2e8ee;border-radius:10px;color:#425466;font-size:12px;font-weight:800;text-align:center}.pressure-scene i{height:5px;background:repeating-linear-gradient(90deg,#a8ba42 0 16px,transparent 16px 27px)}.pressure-scene b{font-size:12px}.pressure-equation{margin-top:12px;padding:10px;background:#f4f7f9;border-radius:9px;color:#465267;font-size:13px;line-height:1.45}
.lesson-deck .deck-stage:has(.de-gap-study:not([hidden])) { align-items:start; }
@media(max-width:760px){
 .learn-page .lesson-deck { padding:14px; margin-top:6px; }
 .lesson-deck .deck-stage { grid-template-columns:minmax(0,1fr); gap:14px; min-height:0; padding:14px 0; }
 .lesson-deck .deck-card__copy { order:-1; }
 .lesson-deck .deck-card__copy h2 { font-size:29px; margin-bottom:8px; }
 .lesson-deck .deck-card__copy>p { font-size:15px; line-height:1.45; }
 .lesson-deck .deck-header { font-size:12px; gap:8px 12px; padding-bottom:10px; }
 .lesson-deck .deck-restart { font-size:11px; margin-left:auto; }
 .lesson-deck .driver-explorer .de-svg { height:165px; }
 .lesson-deck .driver-explorer[data-explorer-mode="intro"] .de-svg { height:220px; }
 .lesson-deck .motion-lab,.lesson-deck .relationship-map { padding:14px; }
 .motion-lab text,.relationship-map [data-rel-node] text { font-size:11px; }
 .lesson-deck .deck-navigation { position:sticky; bottom:0; z-index:5; background:#fff; padding:10px 0; }
 .lesson-deck .deck-navigation label { display:block; font-size:12px; }
 .lesson-deck .deck-navigation button { min-height:40px; padding:7px 13px; }
}

/* The dedicated study view replaces site-footer scrolling with lesson navigation. */
body:has(.lesson-deck) .site-footer { display:none; }
body:has(.lesson-deck) #main-content { padding-bottom:12px; }
@media(max-width:540px){
 .learn-page .lesson-deck { padding:12px; margin-top:0; }
 .lesson-deck .deck-card__copy>p { font-size:14px; line-height:1.4; }
 .lesson-deck .deck-card__copy h2 { font-size:27px; }
 .lesson-deck .deck-stage { gap:10px; padding:12px 0; }
 .lesson-deck .driver-explorer .de-svg { height:150px; }
 .lesson-deck .driver-explorer .de-info p { font-size:12px; }
 .lesson-deck .deck-header .deck-restart { font-size:10px; }
 .lesson-deck>details.deck-details { font-size:11px; padding:6px 9px; }
 .lesson-deck .deck-navigation { margin-bottom:-5px; }
}

/* 01.01 Lane A: real-photo studies retain one stable frame while the selected subject changes. */
.parts-media,.motion-media,.relationship-media{position:relative;isolation:isolate}.photo-overlay{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}.part-mark{opacity:0;stroke-linejoin:round;transition:opacity .16s ease}.part-mark--fixed{fill:rgba(148,196,28,.46);stroke:#486600;stroke-width:7}.part-mark--moving{fill:rgba(36,157,202,.42);stroke:#075778;stroke-width:7}.part-mark--suspension{fill:none;stroke:#d68b23;stroke-width:15}.parts-study[data-parts-visual=all] .part-mark{opacity:.72}.parts-study[data-parts-visual=fixed] .part-mark--fixed,.parts-study[data-parts-visual=moving] .part-mark--moving,.parts-study[data-parts-visual=suspension] .part-mark--suspension{opacity:1}.parts-study[data-parts-visual=fixed] .parts-media img{object-position:22% 70%;transform:scale(1.12)}.parts-study[data-parts-visual=moving] .parts-media img{object-position:70% 42%;transform:scale(1.14)}.parts-study[data-parts-visual=suspension] .parts-media img{object-position:52% 45%;transform:scale(1.1)}.parts-media img,.relationship-media img{transition:transform .16s ease,object-position .16s ease}.motion-media{background:#edf1f2}.motion-media>img{opacity:.2;filter:grayscale(1);object-fit:cover!important}.motion-assembly{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}.motion-frame{fill:#7c8991;stroke:#354652;stroke-width:6}.motion-gap{fill:#f0f2e9;stroke:#354652;stroke-width:4}.motion-cone{fill:#47606a;stroke:#233743;stroke-width:6}.motion-coil{fill:#c97a34;stroke:#754116;stroke-width:6}.motion-cap{fill:#283e49}.motion-ghost{fill:none;stroke:#78909c;stroke-width:5;stroke-dasharray:10 9;opacity:.45}.motion-ghost--in{transform:translateX(-42px)}.motion-ghost--out{transform:translateX(42px)}.motion-assembly [data-moving-assembly]{transform:translateX(var(--assembly-shift,0));transition:transform .09s linear}.motion-assembly [data-motion-surround],.motion-assembly [data-motion-spider]{fill:none;stroke:#b27a30;stroke-width:12;stroke-linecap:round;transition:d .09s linear}.motion-photo[data-motion-state=inward] [data-motion-surround]{d:path('M603 105 Q659 145 603 190 M603 260 Q659 305 603 345')}.motion-photo[data-motion-state=outward] [data-motion-surround]{d:path('M687 105 Q741 145 687 190 M687 260 Q741 305 687 345')}.motion-photo[data-motion-state=inward] [data-motion-spider]{d:path('M248 175 Q298 225 248 275')}.motion-photo[data-motion-state=outward] [data-motion-spider]{d:path('M332 175 Q382 225 332 275')}.motion-assembly text{font:800 16px system-ui;letter-spacing:.04em;fill:#243943}.relationship-media .photo-overlay{opacity:.72}.component-story[data-relationship-media=coil] .photo-overlay{display:none}.component-story[data-relationship-media=coil] .relationship-media img{object-fit:contain;background:#f5f6f4}.component-story[data-relationship-media=gap] .relationship-media img{object-position:18% 75%;transform:scale(1.15)}.component-story[data-relationship-media=former] .relationship-media img{object-position:70% 40%;transform:scale(1.14)}.component-story[data-relationship-media=suspension] .relationship-media img{object-position:51% 38%;transform:scale(1.12)}.component-story[data-relationship-media=gap] .part-mark--fixed,.component-story[data-relationship-media=former] .part-mark--moving,.component-story[data-relationship-media=suspension] .part-mark--suspension{opacity:1}.motion-overlay{display:none}
@media(prefers-reduced-motion:reduce){.part-mark,.parts-media img,.relationship-media img,.motion-assembly [data-moving-assembly],.motion-assembly [data-motion-surround],.motion-assembly [data-motion-spider]{transition:none}}
@media(max-width:760px){.motion-assembly text{font-size:12px}.part-mark--suspension{stroke-width:12}.motion-ghost{stroke-width:4}}

/* 01.01 premium real-media revision. Every interactive panel has a reserved frame. */
.lesson-deck .deck-stage{min-height:520px}.real-media{margin:0;overflow:hidden;border:1px solid #d9e1e7;border-radius:18px;background:#eef2f4;aspect-ratio:16/9}.real-media img{display:block;width:100%;height:100%;object-fit:cover}.hero-media{aspect-ratio:3/2}.parts-study,.motion-photo,.component-story{display:grid;gap:14px}.parts-study>.real-media,.motion-photo>.real-media,.component-story>.real-media{height:280px;aspect-ratio:auto}.parts-study>.real-media img,.motion-photo>.real-media img,.component-story>.real-media img{object-fit:contain;background:#f5f6f4}.parts-controls,.relationship-map__controls{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}.parts-controls button,.relationship-map__controls button{min-height:48px;border:1px solid #b7c0cc;border-radius:9px;background:#fff;color:#263244;padding:8px;font:700 13px/1.2 inherit;cursor:pointer}.parts-controls button[aria-pressed=true],.relationship-map__controls button[aria-pressed=true]{background:#e8f9a6;border-color:#8cae00;color:#273a00}.fixed-explanation{box-sizing:border-box;min-height:112px;padding:14px 16px;border:1px solid #dce6c0;border-radius:12px;background:#fbfdf7;color:#425166}.fixed-explanation strong{display:block;font-size:14px}.fixed-explanation p{margin:6px 0 0!important;min-height:0!important;font-size:14px!important}.motion-photo{position:relative}.motion-overlay{position:absolute;inset:20px;display:flex;align-items:end;justify-content:space-between;gap:8px;pointer-events:none}.motion-overlay span{padding:7px 9px;border-radius:999px;background:rgba(27,39,49,.86);color:#fff;font-size:11px;font-weight:800;transform:translateY(calc(var(--motion-guide, 0) * 5px))}.motion-lab__controls{padding:0}.component-story{position:relative}.component-copy{min-height:140px}.voice-coil-inset{position:absolute;right:16px;top:16px;width:160px}.voice-coil-inset .real-media{aspect-ratio:1}.sound-wave-media{height:290px;aspect-ratio:auto}.sound-wave-media img{object-fit:contain;background:#10151a}.equation-card{margin-top:12px;padding:16px;border:1px solid #bdcf70;border-radius:12px;background:#f8fce9;color:#344333}.equation-card>strong,.equation-card code{display:block}.equation-card code{margin:10px 0;font-size:24px;font-weight:800;background:transparent}.equation-card dl{display:grid;grid-template-columns:auto 1fr;gap:4px 12px;margin:10px 0;font-size:13px}.equation-card dt{font-weight:800}.equation-card dd{margin:0}.equation-card p{min-height:0!important;margin:8px 0 0!important;font-size:13px!important}.signal-chain ol{margin-bottom:12px}.signal-chain ol button{min-height:80px}.pressure-equation p{min-height:0!important;margin:7px 0!important;font-size:13px!important}
@media(max-width:760px){.lesson-deck .deck-stage{min-height:0}.parts-study>.real-media,.motion-photo>.real-media,.component-story>.real-media{height:220px}.parts-controls,.relationship-map__controls{grid-template-columns:repeat(2,minmax(0,1fr))}.fixed-explanation{min-height:126px}.voice-coil-inset{width:105px;right:10px;top:10px}.sound-wave-media{height:210px}.motion-overlay{inset:10px;align-items:start;flex-wrap:wrap}.motion-overlay span{font-size:10px}.equation-card code{font-size:20px}}

.learn-page:has(.lesson-deck) { padding:12px 24px 0; }
/* Cards 6–7: paired local-air studies and a stable listener-point comparison. */
.air-study{display:grid;gap:16px;padding:22px;border:1px solid var(--line);border-radius:18px;background:#fff}.air-study__module{display:grid;grid-template-columns:minmax(180px,.72fr) minmax(0,1.28fr);gap:18px;align-items:center;padding:16px;border:1px solid #dce5ea;border-radius:13px;background:#fbfcfc}.air-study__module h3{margin:0 0 8px;color:#263b47;font-size:20px}.air-study__module p{min-height:0!important;margin:0!important;color:#465267;font-size:15px!important;line-height:1.5}.air-study__media{height:auto;aspect-ratio:20/7;border-radius:10px;background:#f4f7f8}.air-study__media img{object-fit:contain}.air-study__note{min-height:0!important;margin:0!important;padding:10px 12px;border-left:3px solid #9bc900;color:#526174!important;font-size:13px!important;line-height:1.45}.pressure-lab{display:grid;gap:12px}.pressure-lab .pressure-purpose,.pressure-lab .pressure-support{min-height:0!important;margin:0!important}.pressure-purpose{color:#263b47!important;font-size:17px!important}.pressure-support{font-size:14px!important}.pressure-lab__buttons{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));margin:0}.pressure-lab__buttons button{min-height:50px}.local-air{position:relative;display:grid;grid-template-columns:1fr 86px;align-items:center;gap:16px;box-sizing:border-box;height:188px;padding:24px 20px;border:1px solid #dce5ea;border-radius:13px;background:#f8fafb;overflow:hidden}.local-air__particles{display:flex;align-items:center;justify-content:space-around;height:72px;padding:0 10px;border-top:2px solid #d5e0e5;border-bottom:2px solid #d5e0e5}.local-air__particles i{display:block;width:15px;height:15px;border-radius:50%;background:#50636e;transition:transform .18s ease,background-color .18s ease}.local-air__ear{display:grid;width:72px;height:72px;place-items:center;border:2px solid #50636e;border-radius:50%;background:#fff}.local-air__ear span{width:26px;height:37px;border:7px solid #b6c779;border-left:0;border-radius:0 26px 26px 0}.local-air__label{position:absolute;right:20px;bottom:14px;display:grid;gap:2px;color:#526174;font-size:12px;text-align:right}.local-air__label b{color:#344653}.local-air__label span{font-weight:800}.pressure-lab[data-pressure=above] .local-air{background:#f8fce9;border-color:#c8da80}.pressure-lab[data-pressure=above] .local-air__particles{justify-content:center;gap:9px}.pressure-lab[data-pressure=above] .local-air__particles i{background:#638000}.pressure-lab[data-pressure=below] .local-air{background:#f4f9fc;border-color:#b8d3df}.pressure-lab[data-pressure=below] .local-air__particles{justify-content:space-between}.pressure-lab[data-pressure=below] .local-air__particles i{background:#257d9e}.local-air__copy{box-sizing:border-box;min-height:92px;padding:13px 15px;border:1px solid #dce6c0;border-radius:12px;background:#fbfdf7;color:#425166}.local-air__copy strong{font-size:14px}.local-air__copy p{min-height:0!important;margin:6px 0 0!important;font-size:14px!important}.pressure-equation{margin:0}.pressure-equation code{display:block;margin:8px 0;font-size:21px;font-weight:800;color:#263b47}@media(max-width:760px){.air-study{padding:14px}.air-study__module{grid-template-columns:1fr;gap:10px;padding:13px}.air-study__media{width:100%}.pressure-lab__buttons{grid-template-columns:1fr}.local-air{height:188px;grid-template-columns:1fr 62px;padding:18px 12px;gap:8px}.local-air__ear{width:54px;height:54px}.local-air__label{right:12px;bottom:10px;font-size:10px}.local-air__particles{padding:0 3px}.local-air__particles i{width:12px;height:12px}.pressure-equation code{font-size:19px}}@media(prefers-reduced-motion:reduce){.local-air__particles i{transition:none}}
@media(max-width:540px){
 .learn-page:has(.lesson-deck) { padding:8px 9px 0; }
 .lesson-deck .deck-header { flex-wrap:nowrap; font-size:11px; }
 .lesson-deck .deck-restart { max-width:96px; text-align:right; }
 .lesson-deck .signal-chain,.lesson-deck .air-wave,.lesson-deck .pressure-lab,.lesson-deck .deck-quiz { padding:14px; }
 .lesson-deck .air-wave p,.lesson-deck .pressure-lab p,.lesson-deck .signal-chain p { font-size:14px; min-height:0; }
 .lesson-deck .deck-completion { padding:10px; font-size:12px; }
 .pressure-scene { grid-template-columns:1fr 1fr 1fr; font-size:10px; }
}

/* V6 quiz and unobscured navigation */
.quiz-diagram{margin:12px 0 20px;padding:14px;background:#f6f8f9;border:1px solid #dde4e8;border-radius:12px}.quiz-diagram svg{display:block;width:100%;max-height:125px}.quiz-diagram text{font:14px system-ui;fill:#425363}.quiz-diagram figcaption{font-size:13px;line-height:1.5;color:#506171}.lesson-deck .deck-navigation{position:static;bottom:auto;margin-bottom:0}.lesson-deck .deck-stage{scroll-margin-top:90px}@media(max-width:760px){.lesson-deck .deck-card__visual{order:0}.lesson-deck .deck-navigation{position:static;padding:16px 0;gap:8px}.lesson-deck .deck-navigation label{display:block}.lesson-deck .deck-header{padding-top:12px}}

/* V6 coordinated air-field model */
.air-technical {border:1px solid #d9e2e8;border-radius:16px;background:#fff;padding:clamp(16px,3vw,30px);color:#243d4d}
.air-heading span {font-size:11px;letter-spacing:.12em;font-weight:700;color:#627787}
.air-heading h3 {margin:8px 0 0;font-size:clamp(20px,3vw,29px);line-height:1.2}
.air-field {display:block;width:100%;height:auto;margin:18px 0 0;overflow:visible}
.air-field text {font:600 15px system-ui;fill:#425e71}
.air-field .air-key {font-size:15px;fill:#905612}
.air-field .air-tracked {fill:#bd731f;stroke:#fff;stroke-width:1.5}
.air-controls {display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:12px 0;border-top:1px solid #e2e8ed}
.air-controls label {display:flex;align-items:center;gap:12px;flex:1;min-width:210px;font-size:14px}
.air-controls input {width:100%;min-width:90px;accent-color:#245a79}
.air-technical button {background:#fff;border:1px solid #b7c8d2;border-radius:7px;min-height:44px;padding:10px 15px;color:#244b65;cursor:pointer}
.air-technical button[aria-pressed="true"] {background:#e7f1f7;border-color:#245a79;box-shadow:inset 0 0 0 1px #245a79}
.air-observation {padding:18px 20px;background:#f1f6f9;border-left:3px solid #416e8a;border-radius:0 8px 8px 0}
.air-observation>span {display:block;text-transform:uppercase;font-size:11px;letter-spacing:.1em;margin-bottom:7px}
.air-observation strong {display:block;font-size:17px;line-height:1.4;min-height:48px}
.air-observation p,.air-pressure-readout p {font-size:15px;line-height:1.55;margin:8px 0 0}
.air-model-note {font-size:12px!important;line-height:1.65;color:#607584;margin:18px 0 0}
.air-pressure-readout {display:flex;align-items:center;gap:22px;padding:20px;background:#f1f6f9;border-radius:10px}
.air-pressure-readout>strong {font:600 24px ui-monospace,monospace;white-space:nowrap;color:#21516e}
.air-pressure-scale {display:flex;justify-content:space-between;position:relative;margin:18px 0 25px;padding-bottom:18px;border-bottom:2px solid #9caebb;font-size:12px}
.air-pressure-scale i {position:absolute;bottom:-6px;width:10px;height:10px;transform:translateX(-50%);border-radius:50%;background:#245a79;outline:3px solid white}
.pressure-technical .pressure-equation {margin-top:22px}
@media(max-width:600px){.air-technical{padding:14px 10px}.air-field{margin:18px -5px 0;width:calc(100% + 10px)}.air-field text{font-size:19px}.air-field .air-key{font-size:17px}.air-pressure-readout{flex-direction:column;align-items:flex-start;gap:10px;padding:16px}.air-pressure-scale{font-size:10px;gap:6px}.air-observation{padding:14px}.air-observation strong{font-size:16px}.air-controls label{flex-basis:100%}.pressure-technical .pressure-lab__buttons{display:flex;flex-wrap:wrap;gap:6px;margin-top:16px}.pressure-technical .pressure-lab__buttons button{padding:10px;font-size:12px}}

/* V6 original technical driver study */
.td-panel{border:1px solid #d7e0e5;border-radius:16px;overflow:hidden;background:radial-gradient(ellipse at 60% 40%,#fff 20%,#f3f6f8 100%);box-shadow:0 12px 35px #18344208}
.td-kicker{display:flex;justify-content:space-between;gap:16px;padding:18px 22px 0;font-size:10px;font-weight:700;letter-spacing:.12em;color:#647985}
.td-svg{display:block;width:100%;height:auto;max-height:440px;font-family:inherit}
.td-svg [data-technical-part]{transition:opacity .18s}
.td-key{display:flex;flex-wrap:wrap;justify-content:center;gap:12px 22px;padding:8px 18px;font-size:12px;color:#4e6572}
.td-key span{display:flex;align-items:center;gap:7px}.td-key i{width:9px;height:9px;border-radius:50%}
.td-boundary{font-size:12px!important;line-height:1.5!important;color:#6a7b86!important;padding:0 20px;margin:12px 0 18px!important;max-width:none!important}
.td-controls{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin:16px 0}
.td-controls button,.td-parts button{border:1px solid #d4dfe5;border-radius:8px;background:white;padding:10px 13px;color:#3e5361;cursor:pointer;font:inherit;font-size:13px}
.td-controls button[aria-pressed=true],.td-parts button[aria-pressed=true]{background:#e7f0f5;border-color:#486d85;color:#214d68;box-shadow:inset 0 0 0 1px #486d85}
.td-controls button:focus-visible,.td-parts button:focus-visible{outline:3px solid #79a9cb;outline-offset:2px}
.td-controls label{display:flex;align-items:center;gap:8px;font-size:13px}.td-controls input{width:160px;accent-color:#426e8b}
.td-controls output{font-size:11px;letter-spacing:.12em;color:#506b7b}
.td-parts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:7px}
.td-parts button{text-align:left;display:flex;align-items:center;gap:8px;padding:10px;font-size:12px}
.td-parts b{border:1px solid #cedae1;border-radius:50%;min-width:23px;height:23px;text-align:center;line-height:22px;font-size:11px}
.td-explanation{padding:17px 20px;background:#f5f8fa;border-left:3px solid #5f8297;border-radius:0 8px 8px 0;margin:15px 0;min-height:100px;color:#3c5362;font-size:14px;line-height:1.65}
.td-explanation p{margin:7px 0 0!important;font-size:14px!important;line-height:1.65!important}
.td-hero-story{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:22px 8px;font-size:13px;color:#426071}
.td-hero-story b{display:block;font-size:10px;letter-spacing:.14em;color:#91a1ad;margin-bottom:5px}
@media(max-width:600px){.td-kicker{padding:14px 12px 0;font-size:10px;letter-spacing:.06em}.td-kicker span:last-child{display:none}.td-svg{min-height:240px}.td-key{font-size:10px;gap:8px 12px}.td-boundary{padding:0 12px;font-size:11px!important}.td-parts{grid-template-columns:repeat(2,minmax(0,1fr))}.td-controls button{flex:1 1 42%;font-size:12px}.td-controls label{width:100%;justify-content:center}.td-controls input{width:50%}.td-explanation{padding:14px;min-height:130px}.td-hero-story{font-size:11px;gap:6px}.td-hero-story>span[aria-hidden]{font-size:15px}.td-leader text{font-size:19px}}
@media(prefers-reduced-motion:reduce){.td-svg [data-technical-part]{transition:none}}
.td-3d-stage{height:390px;position:relative;width:100%;overflow:hidden;touch-action:pan-y}
.td-3d-stage canvas{display:block;width:100%!important;height:100%!important}
.td-view-controls{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:7px;padding:0 14px 12px;font-size:11px;color:#71848f}
.td-view-controls span{margin-right:auto}.td-view-controls button{font:inherit;font-size:11px;background:#fff;border:1px solid #d3dfe5;border-radius:6px;padding:7px 10px;color:#496271;cursor:pointer}
.td-view-controls button[aria-pressed=true]{background:#e7f0f5;border-color:#68889b;color:#214d68}
.td-section-detail{margin:0 14px 14px;border:1px solid #dce5e9;border-radius:8px;background:#ffffffa8}.td-section-detail summary{font-size:12px;cursor:pointer;padding:12px;color:#526c7c}
@media(max-width:600px){.td-3d-stage{height:300px}.td-view-controls span{width:100%;text-align:center}.td-view-controls button{flex:1}}

/* Mobile air diagram legend: readable HTML labels rather than scaled SVG text. */
.air-mobile-legend{display:none}
@media(max-width:600px){.air-field text{display:none}.air-field{margin-top:0;margin-bottom:-24px}.air-mobile-legend{display:grid;grid-template-columns:1fr 1fr;gap:12px 16px;padding:0 6px 16px;font-size:14px;line-height:1.5}.air-mobile-legend div{display:flex;flex-direction:column}.air-mobile-legend span{color:#536c7c}.air-mobile-legend p{grid-column:1/-1;margin:0;font-size:14px;line-height:1.5}.air-mobile-legend i{display:inline-block;width:9px;height:9px;background:#bd731f;border-radius:50%;margin-right:6px}.air-mobile-legend b{font-weight:650}}