.pe-course{margin:0;background:#fbfcf8;color:#1b332b;font:16px/1.65 Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;-webkit-font-smoothing:antialiased}
.pe-course *{box-sizing:border-box}.pe-course a{color:inherit}.pe-course button,.pe-course a{touch-action:manipulation}.pe-course button{font:inherit;cursor:pointer}.pe-course button:disabled{opacity:.4;cursor:default}.pe-course a:focus-visible,.pe-course button:focus-visible{outline:3px solid #7b942c;outline-offset:4px}
.course-home{max-width:1240px;padding:0 36px;margin:auto}.home-hero{display:grid;grid-template-columns:1.8fr 1fr;align-items:center;padding:88px 0 72px;gap:72px}.eyebrow{font-size:11px;letter-spacing:2px;font-weight:750;color:#5c7350;margin:0 0 22px}.home-hero h1{font-size:clamp(44px,5.8vw,76px);line-height:1.06;letter-spacing:-3.5px;font-weight:650;margin:0 0 24px}.home-hero h1 span{color:#658444}.hero-description{max-width:500px;font-size:17px;color:#5a695e;line-height:1.8}.hero-actions{display:flex;align-items:center;flex-wrap:wrap;gap:24px;margin-top:32px}.course-button{display:inline-flex;align-items:center;justify-content:center;gap:20px;background:#214c3c;color:#fff!important;border:1px solid #214c3c;border-radius:7px;padding:13px 19px;font-size:14px;font-weight:600;text-decoration:none;transition:background .15s}.course-button:hover{background:#153a2c}.text-link{font-size:13px;text-decoration:none;border-bottom:1px solid #b8c4ab;padding-bottom:3px}.hero-footnote{font-size:12px;color:#647264;margin:18px 0 0}.hero-aside{padding-left:40px;border-left:1px solid #dae3d0;align-self:stretch;display:flex;flex-direction:column;justify-content:center}.hero-aside-number{font:500 110px/1 ui-monospace,monospace;color:#dfe7cf;letter-spacing:-10px}.hero-aside p{font-size:23px;line-height:1.4;letter-spacing:-.5px;color:#5d7055;margin:28px 0}.hero-aside-line{height:5px;background:#a6bc76;width:50px}
.loop-preview{scroll-margin-top:24px;border:1px solid #d7e0d2;background:#fff;border-radius:16px;overflow:hidden;box-shadow:0 12px 50px #243b2310}.preview-heading{padding:30px 32px;display:flex;justify-content:space-between;gap:20px;align-items:center}.preview-heading .eyebrow{margin-bottom:8px}.preview-heading h2{font-size:28px;letter-spacing:-.9px;line-height:1.2;margin:0 0 8px;font-weight:650}.preview-heading p:not(.eyebrow){font-size:14px;color:#61705f;margin:0}.lesson-badge{font-size:9px;letter-spacing:1px;border:1px solid #d7e2c6;border-radius:20px;padding:8px 12px;background:#f4f8ec;white-space:nowrap;color:#5d7343}.visualizer{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid #e2e7dd;border-bottom:1px solid #e2e7dd}.code-panel{background:#18362d;color:#e9f0e3;padding:24px 28px}.panel-heading{display:flex;justify-content:space-between;gap:12px;font-size:10px;letter-spacing:1px;font-weight:600;margin-bottom:24px}.code-panel .panel-heading{color:#a5c0ae}.code-lines{list-style:none;counter-reset:line;padding:0;margin:0}.code-lines li{counter-increment:line;padding:12px 8px;border-radius:6px;border-left:3px solid transparent;white-space:pre;display:flex;gap:18px;font-size:14px}.code-lines li:before{content:counter(line);color:#6e9680;min-width:12px;font:12px/1.8 ui-monospace,monospace}.code-lines code{font:14px/1.8 ui-monospace,SFMono-Regular,Consolas,monospace}.code-lines li.active{background:#314f3f;border-color:#d4e79a}.code-caption{font-size:11px;color:#9bb69e;margin:24px 0 0}.execution-panel{padding:24px 28px;background:#f7f9f2}.execution-panel .panel-heading{color:#748268}.number-cells{display:flex;gap:10px}.number-cell{display:flex;align-items:center;justify-content:center;width:48px;height:44px;border:1px solid #d7dfcf;border-radius:7px;background:white;color:#58694e;font:600 18px/1 ui-monospace,monospace;transition:background .2s}.number-cell.active{background:#d9eaa9;border-color:#98b960;color:#23462c}.execution-details{display:grid;grid-template-columns:1fr 1.2fr;gap:20px;margin-top:26px}.detail-label{display:block;font-size:9px;font-weight:650;letter-spacing:1px;color:#78856d;margin-bottom:8px}.execution-details strong,.execution-details output{font:500 21px/1.4 ui-monospace,monospace;color:#2d4a30}.execution-panel>p{font-size:12px;color:#5b6b54;margin:22px 0 0;min-height:40px}.preview-controls{display:flex;justify-content:space-between;align-items:center;padding:18px 28px;gap:20px}.control-buttons{display:flex;align-items:center;gap:10px}.control-buttons button:not(.course-button){border:1px solid #d8e0d2;border-radius:6px;background:#fff;color:#4b5f43;padding:9px 13px;font-size:12px}.control-buttons .course-button{padding:9px 16px;font-size:12px}.preview-controls>span{font-size:11px;color:#718064}.learning-path{padding:82px 0;scroll-margin-top:24px}.section-heading{display:flex;justify-content:space-between;align-items:flex-end;gap:48px;margin-bottom:28px}.section-heading .eyebrow{margin-bottom:10px}.section-heading h2,.learning-method h2{font-size:35px;letter-spacing:-1.3px;font-weight:650;line-height:1.2;margin:0}.section-heading>p{max-width:340px;color:#66725f;font-size:14px;margin:0}.lesson-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.lesson-card{border:1px solid #dce3d5;border-radius:12px;background:#f4f6ee;padding:24px;text-decoration:none}.lesson-card.available{background:#edf3e1;border-color:#c1d2a5}.lesson-card.available:hover{border-color:#6d8d42}.lesson-top{display:flex;flex-wrap:wrap;align-items:center;gap:10px;justify-content:space-between;font-size:9px;letter-spacing:.8px;color:#637953}.status{font-size:9px;letter-spacing:0;border:1px solid #d5dfc6;border-radius:20px;padding:3px 8px}.lesson-symbol{font-size:56px;line-height:1;color:#719048;margin:32px 0 24px}.lesson-card h3{font-size:21px;font-weight:600;letter-spacing:-.5px;margin:0 0 8px}.lesson-card p{font-size:13px;line-height:1.8;color:#687560;min-height:48px;margin:0 0 26px}.lesson-bottom{font-size:11px;color:#526c3d}.learning-method{border-top:1px solid #dde4d6;padding:48px 0 18px}.learning-method .eyebrow{margin-bottom:12px}.method-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:50px;margin-top:38px}.method-number{font:14px/1.5 ui-monospace,monospace;color:#739055}.method-grid h3{font-size:19px;margin:12px 0 8px;font-weight:600}.method-grid p{font-size:14px;color:#66755f;margin:0}.pe-course .pe-footer{margin-top:64px}
@media(max-width:900px){.home-hero{gap:30px;padding:60px 0}.hero-aside{padding-left:24px}.hero-aside-number{font-size:85px}.lesson-grid{gap:12px}.lesson-card{padding:20px}.section-heading{gap:24px}.preview-heading{align-items:flex-start}.lesson-badge{display:none}}
@media(max-width:700px){.course-home{padding:0 20px}.home-hero{grid-template-columns:1fr;padding:48px 0 38px}.home-hero h1{letter-spacing:-2px}.hero-aside{display:none}.hero-description{font-size:16px}.hero-actions{gap:18px;margin-top:24px}.visualizer{grid-template-columns:1fr}.preview-heading{padding:24px 20px}.code-panel,.execution-panel{padding:22px 20px}.preview-controls{padding:18px 16px}.preview-controls>span{display:none}.code-lines code{font-size:13px}.code-lines li{padding:10px 2px;gap:10px}.learning-path{padding:48px 0}.section-heading{display:block}.section-heading>p{margin-top:16px}.section-heading h2,.learning-method h2{font-size:28px}.lesson-grid,.method-grid{grid-template-columns:1fr}.lesson-card p{min-height:0}.lesson-symbol{margin:20px 0;font-size:42px}.method-grid{gap:24px;margin-top:28px}.learning-method{padding-top:32px}}
@media(prefers-reduced-motion:reduce){.pe-course *{transition:none!important;scroll-behavior:auto!important}}
/* Course overview and lessons share the homepage palette, not legacy article rules. */
.course-overview{padding-top:60px}.course-intro{max-width:760px}.course-intro h1{font-size:clamp(40px,5vw,64px);line-height:1.1;font-weight:650;letter-spacing:-2.5px;margin:0 0 22px}.course-intro h1 span{color:#658444}.course-intro>p:not(.eyebrow){max-width:620px;color:#61715e;font-size:17px}.course-progress{font-size:12px;color:#627558;line-height:1.7}.course-roadmap{display:grid;gap:14px;margin:48px 0}.roadmap-item{display:grid;grid-template-columns:50px 1fr auto;align-items:center;gap:24px;text-decoration:none;border:1px solid #d7e1cf;background:#fff;border-radius:12px;padding:26px 30px}.roadmap-item:hover{border-color:#7a9953;background:#f4f8ec}.roadmap-number{font:20px/1 ui-monospace,monospace;color:#769154}.roadmap-item h2{font-size:23px;letter-spacing:-.6px;font-weight:650;margin:0 0 7px;line-height:1.3}.roadmap-item p{font-size:14px;color:#68795f;margin:0;max-width:680px}.roadmap-meta{display:flex;flex-direction:column;align-items:flex-end;gap:12px;font-size:12px;white-space:nowrap;color:#637954}.course-note{border-top:1px solid #dce4d3;padding:28px 0 0;max-width:780px}.course-note h2{font-size:25px;letter-spacing:-.6px}.course-note p{font-size:14px;color:#65755d}.course-all-link{display:inline-block;margin-top:24px}.foundations-grid{grid-template-columns:repeat(3,1fr)}
.lesson-layout{max-width:1240px;margin:0 auto;padding:48px 36px 0;display:grid;grid-template-columns:244px minmax(0,1fr);gap:60px;align-items:start}.course-sidebar{position:sticky;top:24px;padding-right:20px}.course-back{font-size:12px;color:#5d7650!important;text-decoration:none;display:inline-block;margin-bottom:32px}.course-sidebar .eyebrow{font-size:10px;letter-spacing:1.3px;margin-bottom:14px}.course-sidebar nav{display:grid;gap:6px}.course-outline-link{display:flex;align-items:center;gap:10px;font-size:12px;text-decoration:none;padding:12px 10px;border-radius:7px;color:#617458!important;line-height:1.4}.course-outline-link.current{background:#e8f0dc;color:#294b2e!important;font-weight:650}.course-outline-link:hover{background:#f0f5e7}.outline-number{font:11px/1.5 ui-monospace,monospace;color:#779064}.outline-status{margin-left:auto;color:#52733e}.course-sidebar>.course-progress{margin:22px 10px 0;padding-top:18px;border-top:1px solid #dce5d4}.course-lesson{min-width:0;max-width:830px}.lesson-title{border-bottom:1px solid #dce4d5;padding-bottom:30px;margin-bottom:32px}.lesson-title .eyebrow{margin-bottom:16px}.lesson-title h1{font-size:44px;font-weight:650;letter-spacing:-1.8px;line-height:1.15;margin:0 0 18px}.lesson-lead{font-size:18px;color:#627159;line-height:1.8;margin:0}.lesson-section{margin:0 0 34px}.lesson-section h2,.lesson-lab h2,.lesson-takeaways h2{font-size:25px;letter-spacing:-.7px;font-weight:650;line-height:1.3;margin:0 0 14px}.lesson-section p{font-size:16px;line-height:1.85;color:#4c604b;margin:0 0 16px}.lesson-code{font:13px/1.9 ui-monospace,SFMono-Regular,Consolas,monospace;background:#eef3e7;border:1px solid #d9e2cf;border-radius:8px;padding:18px 20px;white-space:pre;overflow:auto;margin:18px 0}.lesson-code code{font:inherit}.lesson-tip{padding:18px 20px;background:#f5f3df;border-left:3px solid #b6ba77;border-radius:0 8px 8px 0;margin:20px 0}.lesson-tip strong{font-size:12px;text-transform:uppercase;letter-spacing:1px;color:#6a743b}.lesson-tip p{font-size:14px;line-height:1.7;margin:8px 0 0;color:#656c48}.lesson-lab{border:1px solid #cbdcbc;border-radius:13px;overflow:hidden;background:#fff;padding:26px;margin:40px 0}.lesson-lab .eyebrow{margin-bottom:12px}.lesson-lab>p:not(.eyebrow){font-size:14px;color:#667a5c}.lab-inputs{display:flex;align-items:flex-end;gap:14px;flex-wrap:wrap;margin:24px 0}.lab-inputs label{display:grid;gap:6px;flex:1;min-width:120px}.lab-inputs label>span{font-size:11px;letter-spacing:.3px;font-weight:600;color:#5f7452}.lab-inputs input,.lab-inputs select{width:100%;max-width:100%;border:1px solid #bdceb0;border-radius:6px;font:14px/1.5 inherit;color:#244630;background:#fafcf7;padding:10px 12px;min-height:44px}.lab-inputs [aria-invalid="true"]{border-color:#bc5946}.lab-inputs input:focus-visible,.lab-inputs select:focus-visible{outline:3px solid #8ba868;outline-offset:2px}.lesson-visualizer{display:grid;grid-template-columns:1.1fr 1fr;border:1px solid #dce5d2;border-radius:9px;overflow:hidden}.lab-code{background:#19392e;color:#ecf3e5;padding:20px;min-width:0}.lab-code .panel-heading{color:#9cb795}.lab-lines{list-style:none;counter-reset:line;margin:0;padding:0}.lab-lines li{counter-increment:line;display:flex;align-items:baseline;gap:12px;border-left:3px solid transparent;padding:10px 6px;min-height:38px;border-radius:4px}.lab-lines li:before{content:counter(line);font:10px/1.8 ui-monospace,monospace;color:#799e7b;flex-shrink:0;min-width:10px}.lab-lines code{font:12px/1.8 ui-monospace,monospace;white-space:pre-wrap;overflow-wrap:anywhere;min-width:0}.lab-lines li.active{background:#34513c;border-left-color:#d2e597}.lab-state{padding:20px;background:#f4f8ee;min-width:0}.lab-state .panel-heading{color:#6a8059;font-size:9px}.binding-list{min-height:90px;margin-bottom:20px}.binding-list>p{font-size:12px;color:#849277;margin:0}.binding{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:10px;padding:10px 0;border-bottom:1px solid #dce6cf;animation:binding-appear .2s ease-out}.binding>span{font:11px/1.5 ui-monospace,monospace;color:#66804d}.binding>strong{font:600 14px/1.5 ui-monospace,monospace;color:#29482b;overflow-wrap:anywhere;white-space:pre-wrap}.binding>small{font-size:9px;background:#e4edd8;color:#5b7247;border-radius:4px;padding:2px 5px}.lab-output{font:13px/1.8 ui-monospace,monospace;white-space:pre-wrap;overflow-wrap:anywhere;color:#314c31;background:#fff;border:1px solid #dee7d4;border-radius:6px;padding:12px;margin:8px 0 0;min-height:48px}.lab-output.lab-error{color:#963f29;background:#fff1eb;border-color:#e8bbab}.lab-description{min-height:42px;margin:18px 0!important;font-size:13px!important}.lab-controls{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.lab-controls button{font-size:12px;padding:9px 14px;border:1px solid #cad9bd;border-radius:6px;background:#fff;color:#49613c;min-height:40px}.lab-controls .course-button{background:#214c3c}.lesson-quiz{background:#f1f5e7;border:1px solid #d5e1c3;border-radius:12px;padding:26px;margin:40px 0}.lesson-quiz .eyebrow{margin-bottom:16px}.lesson-quiz fieldset{border:0;padding:0;margin:0;min-width:0}.lesson-quiz legend{font-size:19px;font-weight:600;line-height:1.5;letter-spacing:-.4px;margin-bottom:18px;padding:0}.quiz-option{display:flex;align-items:center;gap:12px;border:1px solid #d2dec2;border-radius:7px;padding:13px 15px;margin-bottom:10px;background:#fff;cursor:pointer;font-size:14px;color:#42573a;line-height:1.5}.quiz-option:hover{border-color:#83a35c}.quiz-option:has(input:checked){background:#e5eed6;border-color:#7e9c56}.quiz-option input{accent-color:#375b36;width:16px;height:16px;flex-shrink:0;margin:0}.quiz-option input:focus-visible{outline:3px solid #7b942c;outline-offset:4px}.quiz-actions{display:flex;align-items:center;gap:16px;margin-top:12px}.quiz-actions .course-button{font-size:12px;padding:10px 16px}.quiz-hint{font-size:11px;color:#6d805d}.quiz-feedback{font-size:14px;line-height:1.8;margin:18px 0 0;padding:14px 16px;border-radius:7px;background:#fff}.quiz-correct{border-color:#91b475}.quiz-correct .quiz-feedback{color:#34552f;background:#e1edce}.quiz-wrong .quiz-feedback{color:#805533;background:#faf0dc}.quiz-feedback[hidden]{display:none}.lesson-takeaways{border-top:1px solid #dbe4d1;padding-top:28px}.lesson-takeaways .eyebrow{margin-bottom:12px}.lesson-takeaways ul{padding-left:20px;color:#4c6342;font-size:15px;line-height:1.8}.lesson-completion{border:1px solid #d8e2cc;border-radius:8px;background:#f3f6ed;padding:16px;font-size:13px;color:#698059;margin-top:24px}.lesson-completion.is-complete{background:#e4f0d4;border-color:#a2bf7d;color:#34572b}.lesson-pagination{display:flex;justify-content:space-between;gap:24px;border-top:1px solid #d7e1cd;margin-top:32px;padding-top:24px}.lesson-pagination a{display:grid;gap:6px;text-decoration:none;max-width:48%}.lesson-pagination span{font-size:11px;color:#7a8b69}.lesson-pagination strong{font-size:14px;color:#426135;font-weight:600}.lesson-pagination a:hover strong{text-decoration:underline}.next-lesson{text-align:right}.pe-course .course-lesson{float:none;width:auto;margin:0;background:none;padding:0}.course-lesson noscript p{font-size:13px;color:#5d7252}.course-lesson details{font-size:14px;margin-top:18px}.course-lesson summary{cursor:pointer}
@keyframes binding-appear{from{opacity:.4;transform:translateY(3px)}to{opacity:1;transform:translateY(0)}}
@media(max-width:1000px){.lesson-layout{grid-template-columns:200px minmax(0,1fr);gap:30px;padding:36px 24px 0}.course-sidebar{padding-right:0}.lesson-visualizer{grid-template-columns:1fr}.binding-list{min-height:0}.lesson-title h1{font-size:37px}.lab-code .panel-heading{margin-bottom:15px}.lab-state .panel-heading{margin-bottom:14px}}
@media(max-width:700px){.foundations-grid{grid-template-columns:1fr}.course-overview{padding-top:38px}.roadmap-item{grid-template-columns:28px 1fr;gap:14px;padding:20px}.roadmap-item h2{font-size:20px}.roadmap-item p{font-size:13px}.roadmap-meta{grid-column:2;flex-direction:row;justify-content:space-between;align-items:center}.course-intro h1{letter-spacing:-1.8px}.course-intro>p:not(.eyebrow){font-size:16px}.lesson-layout{display:block;padding:24px 20px 0}.course-sidebar{position:static;border-bottom:1px solid #dce5d4;margin-bottom:32px;padding-bottom:20px}.course-back{margin-bottom:18px}.course-sidebar nav{display:flex;overflow:auto;padding:0 0 6px;gap:6px}.course-outline-link{flex-shrink:0;padding:10px;font-size:11px}.course-sidebar>.course-progress{margin:10px 0 0;padding:0;border:0}.course-sidebar .eyebrow{margin-bottom:8px}.lesson-title h1{font-size:34px;letter-spacing:-1.2px}.lesson-lead{font-size:16px}.lesson-section p{font-size:15px;line-height:1.8}.lesson-section h2,.lesson-lab h2,.lesson-takeaways h2{font-size:23px}.lesson-lab,.lesson-quiz{padding:20px;margin:30px 0}.lab-code,.lab-state{padding:16px}.lesson-code{padding:14px;font-size:12px}.lesson-quiz legend{font-size:17px}.quiz-option{font-size:13px;padding:12px}.lesson-pagination strong{font-size:12px}.lab-inputs{gap:12px}.binding>strong{font-size:13px}}
@media(prefers-reduced-motion:reduce){.binding{animation:none}}

/* One idea at a time, with readable fallbacks when JavaScript is unavailable. */
.lesson-stage[hidden],.lesson-player-progress[hidden],.lesson-player-controls[hidden]{display:none!important}
.has-player .lesson-title{margin-bottom:24px}.lesson-player-progress{margin-bottom:28px}.player-progress-top{display:flex;justify-content:space-between;gap:16px;font-size:12px;color:#65766e;margin-bottom:10px}.player-progress-track{height:5px;background:#e2ebe5;border-radius:8px;overflow:hidden}.player-progress-track>span{display:block;height:100%;background:#25845b;transition:width .3s ease}.has-player .lesson-stage{min-height:470px}.lesson-stage h2:focus,.lesson-stage legend:focus{outline:none}.has-player .lesson-section,.has-player .lesson-lab,.has-player .lesson-quiz,.has-player .lesson-takeaways{margin-top:0;margin-bottom:24px}.stage-invitation{font-size:14px;color:#64756c;max-width:600px}.lesson-player-controls{display:flex;align-items:center;justify-content:space-between;gap:16px;border-top:1px solid #dfe8e1;padding-top:22px;margin-top:26px}.lesson-player-controls>button{border:1px solid #cedbd2;border-radius:8px;background:white;color:#365447;padding:12px 16px;font:inherit;font-size:13px;cursor:pointer}.lesson-player-controls>button.course-button{background:#216a49;color:white;border-color:#216a49}.lesson-player-controls button:disabled{opacity:.45;cursor:default}.player-step-dots{display:flex;gap:7px}.player-step-dots button{width:20px;height:28px;padding:0;border:0;background:transparent;cursor:pointer;position:relative}.player-step-dots button:after{content:'';display:block;width:7px;height:7px;margin:auto;border-radius:50%;background:#c9d9cd}.player-step-dots button[aria-current=step]:after{background:#237749;box-shadow:0 0 0 4px #e1efe6}.concept-animation{margin:22px 0 24px;border:1px solid #d8e7dc;background:linear-gradient(135deg,#f0f8f2,#f9fcf7);border-radius:14px;padding:24px}.concept-animation-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:25px}.concept-animation-heading>span{font-size:10px;font-weight:700;letter-spacing:1.6px;color:#46735c}.concept-animation-heading button{border:0;background:transparent;color:#46735c;font:inherit;font-size:12px;cursor:pointer}.lesson-layout:not(.has-player) [data-animation-replay]{display:none}.concept-sequence{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;align-items:center;gap:12px}.concept-node{align-self:stretch;border:1px solid #d7e6db;background:#fff;border-radius:10px;padding:18px 12px;text-align:center;min-width:0}.concept-label{display:block;font-size:11px;color:#62766a;margin-bottom:14px}.concept-value{display:block;font:600 16px/1.5 monospace;color:#215e3e;overflow-wrap:anywhere;white-space:pre-wrap}.concept-node p{font-size:12px!important;line-height:1.5!important;color:#607166;margin:12px 0 0!important}.concept-arrow{color:#56926a;font-size:23px}.concept-caption{font-size:13px!important;line-height:1.6!important;color:#46735c;margin:20px 0 0!important}.lesson-code-detail,.lesson-tip{margin:16px 0}.lesson-code-detail summary,.lesson-tip summary{cursor:pointer;color:#38684c;font-size:14px}.lesson-tip p{font-size:14px}.stage-enter{animation:stage-arrive .35s ease both}.is-playing .concept-node{animation:concept-arrive .6s ease both;animation-delay:calc(var(--node-order)*.65s)}.is-playing .concept-arrow{animation:concept-arrive .4s ease both;animation-delay:calc(var(--node-order)*.65s + .4s)}.stage-enter .quiz-option{animation:stage-arrive .3s ease both}.quiz-feedback:not([hidden]){animation:stage-arrive .25s ease both}.stage-enter .lesson-takeaways li{animation:stage-arrive .4s ease both}.stage-enter .lesson-takeaways li:nth-child(2){animation-delay:.12s}.stage-enter .lesson-takeaways li:nth-child(3){animation-delay:.24s}@keyframes stage-arrive{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}@keyframes concept-arrive{from{opacity:0;transform:translateY(15px) scale(.96)}to{opacity:1;transform:translateY(0) scale(1)}}
@media(max-width:650px){.has-player .lesson-stage{min-height:0}.concept-animation{padding:18px}.concept-sequence{grid-template-columns:1fr;gap:10px}.concept-node{padding:14px;display:grid;grid-template-columns:85px 1fr;align-items:center;text-align:left;gap:8px}.concept-label{margin:0}.concept-value{font-size:14px}.concept-node p{grid-column:2}.concept-arrow{text-align:center;transform:rotate(90deg);font-size:20px}.is-playing .concept-arrow{animation-name:concept-arrow-arrive}.lesson-player-controls{flex-wrap:wrap;gap:12px}.player-step-dots{order:3;flex-basis:100%;justify-content:center}.player-progress-top{font-size:11px}.player-progress-top span:last-child{text-align:right}.has-player .lesson-title{margin-bottom:18px}.lab-controls{flex-wrap:wrap}}
@keyframes concept-arrow-arrive{from{opacity:0;transform:rotate(90deg) translateX(-8px)}to{opacity:1;transform:rotate(90deg) translateX(0)}}
@media(prefers-reduced-motion:reduce){.stage-enter,.is-playing .concept-node,.is-playing .concept-arrow,.stage-enter .quiz-option,.quiz-feedback:not([hidden]),.stage-enter .lesson-takeaways li{animation:none}.player-progress-track>span{transition:none}}
.has-player .lesson-title{padding-bottom:18px}.has-player .lesson-title h1{margin-bottom:0}.has-player .lesson-stage>h2{margin:12px 0 16px}.has-player .lesson-stage>.eyebrow{margin-bottom:12px}.has-player .concept-animation{margin:18px 0;padding:20px}.has-player .concept-animation-heading{margin-bottom:18px}.has-player .concept-node{padding:14px 12px}.has-player .concept-caption{margin-top:16px!important}
@media(max-width:650px){.has-player .concept-animation{padding:16px}}

/* Homepage: show the same watch, experiment, and quiz flow as the course. */
.home-course-facts{display:flex;flex-wrap:wrap;gap:8px 18px;margin-top:28px;color:#526d5b;font-size:12px}.home-course-facts span:before{content:'✓';color:#28714c;margin-right:7px}.home-lesson-preview{background:#edf4e9;border:1px solid #d9e6d6;border-radius:18px;padding:24px;box-shadow:0 18px 50px #1e4d2f08;min-width:0}.home-preview-top{display:flex;justify-content:space-between;gap:12px;font-size:10px;color:#59754f;margin-bottom:18px;letter-spacing:1.3px}.home-preview-top span:last-child{letter-spacing:0}.home-preview-card{display:grid;grid-template-columns:24px minmax(0,1fr);gap:12px;padding:17px;background:#fff;border:1px solid #dae6d4;border-radius:10px;margin-bottom:12px;animation:home-preview-arrive .55s ease both;animation-delay:calc(var(--preview-order)*.5s)}.home-preview-number{font:11px/1.5 monospace;color:#8c9f7c;padding-top:2px}.home-preview-label{font-size:9px;font-weight:600;letter-spacing:1.2px;color:#607953}.home-preview-card h2{font-size:15px;letter-spacing:-.3px;margin:10px 0 14px}.home-variable-demo{display:flex;align-items:center;gap:16px}.home-variable-demo code,.home-variable-demo strong{font:600 16px/1.6 monospace;padding:5px 16px;border-radius:6px;background:#eef5e7;color:#366044}.home-variable-demo>span{color:#7e9a6c;font-size:20px}.home-preview-card pre{white-space:pre-wrap;overflow-wrap:anywhere;font:12px/1.8 monospace;color:#335941;margin:10px 0}.home-preview-result{display:flex;align-items:center;justify-content:space-between;gap:12px;background:#f1f7eb;border-radius:6px;padding:9px 12px}.home-preview-result span{font-size:9px;color:#6e8560}.home-preview-result strong{font:600 12px/1.5 monospace;color:#2d6543}.home-preview-card p{font-size:13px;line-height:1.6;color:#49623e;margin:10px 0}.home-preview-answer{display:flex;align-items:center;gap:10px;color:#32704b;font-size:13px}.home-preview-answer>span:last-child{font-size:11px;color:#75866a}.home-preview-link{display:block;color:#3b6747;text-decoration:none;font-size:12px;margin-top:17px}.home-preview-link:hover{text-decoration:underline}.home-method-description{max-width:620px;color:#627159;line-height:1.8;font-size:16px;margin:20px 0 32px}.home-flow-note{border-top:1px solid #dae4d0;padding-top:22px;margin-top:32px;display:flex;gap:24px;align-items:baseline;justify-content:space-between}.home-flow-note>span{font-size:14px;font-weight:600;color:#37573d}.home-flow-note p{font-size:13px;color:#718267;line-height:1.7;margin:0;max-width:420px}.home-course-invitation{display:flex;align-items:center;justify-content:space-between;gap:32px;border:1px solid #d5e2ce;background:#edf4e7;border-radius:16px;padding:36px;margin:0 0 72px}.home-course-invitation h2{font-size:28px;letter-spacing:-.8px;margin:12px 0}.home-course-invitation p:not(.eyebrow){font-size:14px;color:#667d58;line-height:1.7;margin:0}.home-course-invitation>a{flex-shrink:0}@keyframes home-preview-arrive{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}
@media(max-width:900px){.home-lesson-preview{padding:18px}.home-flow-note{display:block}.home-flow-note p{margin-top:12px}.home-course-invitation{align-items:flex-start;flex-direction:column;padding:26px}}
@media(max-width:650px){.home-course-facts{font-size:11px;margin-top:22px}.home-preview-card{padding:15px;gap:8px}.home-course-invitation h2{font-size:24px}.home-method-description{font-size:15px}.home-course-invitation{margin-bottom:40px}.home-preview-answer{flex-wrap:wrap}.home-preview-answer>span:last-child{flex-basis:100%}}
@media(prefers-reduced-motion:reduce){.home-preview-card{animation:none}}
.home-hero{grid-template-columns:1.15fr 1fr;gap:52px}.home-lesson-flow{margin-top:64px}
@media(max-width:900px){.home-hero{gap:28px}}
@media(max-width:700px){.home-hero{grid-template-columns:1fr}.home-lesson-flow{margin-top:40px}}