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p{font-size:13px;color:var(--muted);margin:0}.eyebrow{display:block;font-size:9px;letter-spacing:2px;color:#809087;font-weight:650;margin-bottom:10px}.edition{font-size:10px;letter-spacing:2px;white-space:nowrap;display:flex;align-items:center;gap:13px}.edition b{font:48px Georgia;color:#bfcbc1}.hero{border:1px solid #d7e4d6;min-height:348px;background:#e8efe3;border-radius:14px;display:grid;grid-template-columns:1.1fr 1fr;overflow:hidden;position:relative}.hero-copy{padding:35px 37px}.pill{display:inline-block;font-size:11px;padding:7px 12px;background:#f7faf4;border:1px solid #d7e2d6;border-radius:30px;color:#52715e}.hero h2{font-size:clamp(25px,2.4vw,34px);line-height:1.5;letter-spacing:-1px;margin:19px 0 13px}.hero p{font-size:12px;color:#677b69;line-height:1.9}.primary,.secondary,.choice,.text-button{border-radius:7px;padding:12px 19px;border:1px solid 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1fr;gap:24px}.three-columns{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.dimension-tags{display:flex;flex-wrap:wrap;gap:10px;margin:25px 0}.dimension-tags span{background:#f1f3ea;border-radius:5px;padding:8px 11px;font-size:12px}.assessment-option{border:1px solid var(--border);border-radius:10px;padding:25px}.assessment-option p{font-size:13px}.quiz-layout{display:grid;grid-template-columns:245px 1fr;gap:24px}.question-map p{font-size:11px;margin:15px 0 8px}.question-map>div{display:flex;gap:7px}.number-button{width:38px;height:38px;background:#f5f6f1;border:1px solid #dce2d7;border-radius:6px;color:#5e6f5e}.number-button.answered{background:#dcebd8}.number-button.current{border:2px solid var(--green)}.question-map small{display:block;margin-top:24px;font-size:10px}.quiz-card{padding:38px}.quiz-card h2{margin:23px 0 35px;font-size:25px}.quiz-card .muted{font-size:12px;margin-top:25px}.bottom-actions{border-top:1px solid var(--border);margin-top:28px;padding-top:20px;display:flex;justify-content:space-between;gap:15px}label{display:block;font-size:14px;font-weight:500;line-height:1.8;margin:20px 0}input:not([type=range]),select,textarea{display:block;width:100%;background:#fff;border:1px solid #cdd9ca;border-radius:7px;padding:13px 14px;margin-top:8px;min-height:47px;color:#294d3a;max-width:100%}textarea{resize:vertical;min-height:90px}input[type=range]{display:block;width:100%;accent-color:var(--green);margin:20px 0;height:30px}.input-unit{display:flex;align-items:center;gap:15px}.input-unit input{flex:1;min-width:0}.input-unit span{white-space:nowrap}.lab-list-item{display:flex;gap:28px;align-items:center}.lab-list-item div{flex:1}.lab-list-item h2{font-size:20px;margin-bottom:6px}.lab-list-item p{font-size:13px;margin:0;color:var(--muted)}.lab-list-item>span:last-child{font-size:12px;white-space:nowrap}.lab-index{font:42px Georgia;color:#aabd9e}.lab-layout{display:grid;grid-template-columns:280px 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#d1ddc8;background:#fbfcf8;border-radius:8px;padding:17px;color:#56714c;min-width:0}.diagram-choice .bar-row{margin:10px 0 16px}.diagram-choice .segment{height:32px;font-size:8px}.diagram-choice .bar-label{font-size:10px}.diagram-choice>span{font-size:11px}.stat span{font-size:12px;color:#7d8d76}.stat strong{display:block;font-size:28px;margin-top:13px}.table-wrap{overflow:auto}table{border-collapse:collapse;width:100%;font-size:13px;text-align:left}td,th{border-bottom:1px solid #e5eade;padding:13px 12px;white-space:nowrap}th{background:#f2f5ed;font-size:12px;color:#718268;font-weight:500}.parent-tips{padding-left:20px;line-height:2.2;font-size:14px}.report-summary{display:flex;align-items:center;gap:60px}.report-summary strong{font:50px Georgia;color:#345a3b}.report-summary strong small{font-size:22px}.report-summary span{display:block;font-size:12px;margin-top:8px;color:#839079}.report-summary p{margin:0;color:#7a8971;font-size:13px}.dimension-results{display:grid;grid-template-columns:repeat(5,1fr);gap:13px}.dimension-results .card{padding:20px 15px}.dimension-results span{font-size:11px}.dimension-results strong{display:block;font-size:30px;margin:18px 0 12px}.dimension-results strong small{font-size:15px}.dimension-results small{font-size:10px}.progress{height:4px;background:#edf1e7;border-radius:5px;margin-bottom:10px}.progress i{display:block;height:4px;background:#73976a;border-radius:5px}.wrong-question{border-bottom:1px solid #e5eadf;padding:18px 0}.wrong-question summary{cursor:pointer;font-size:14px;line-height:1.8}.wrong-question p{font-size:13px;margin-top:15px}.answer-item{border-bottom:1px solid var(--border);padding:20px 0;font-size:13px}.answer-item p{margin:12px 0 0}.empty{padding:60px;text-align:center}.skip-link{position:fixed;top:-100px;left:10px;background:white;padding:10px;z-index:10}.skip-link:focus{top:10px}summary{cursor:pointer}.link-button{vertical-align:middle}.card>button+button{margin-left:12px}
@media(min-width:1500px){main{padding-top:45px}.hero{min-height:390px}.hero-copy{padding:40px 45px}.hero-diagram{margin:40px 55px 30px 0}}
@media(max-width:1150px){.sidebar{width:205px;padding:30px 14px}.main-shell{margin-left:205px}main{padding:30px 25px}.topbar{padding:0 25px}.hero-copy{padding:28px}.hero-diagram{margin-right:22px}.hero h2{font-size:28px}.feature-card{padding:20px 17px 0}.card-meta{display:block}.card-meta span{display:block;margin-top:5px}.lab-layout{grid-template-columns:230px 1fr}.lab-work{padding:24px}.quiz-layout{grid-template-columns:210px 1fr}.question-map{padding:20px}.number-button{width:34px;height:36px}.dimension-results{grid-template-columns:repeat(3,1fr)}}
@media(max-width:900px){.sidebar{position:static;width:auto;height:auto;padding:18px 23px;border-right:0;border-bottom:1px solid var(--border)}.brand{font-size:18px;padding:0}.brand-symbol{width:39px;height:39px;font-size:29px}.brand small{font-size:9px}.nav-caption,.sidebar-bottom{display:none}.sidebar nav{display:flex;gap:4px;overflow:auto;margin-top:15px}.sidebar nav a{white-space:nowrap;font-size:11px;padding:10px;min-height:44px}.sidebar nav a span{font-size:16px;width:16px}.main-shell{margin-left:0}.topbar{height:49px}.hero{grid-template-columns:1fr 1fr}.hero h2{font-size:27px}.home-cards{gap:12px}.feature-card h3{font-size:15px}.home-bottom{flex-wrap:wrap}.home-bottom p{min-width:60%}.lab-layout{grid-template-columns:220px 1fr}.context-card{padding:21px}.context-card h2{font-size:18px}.lab-work{padding:22px}.quiz-card{padding:28px}.diagram-choices{gap:9px}.diagram-choice{padding:10px}}
@media(max-width:620px){main{padding:25px 17px}.topbar{padding:0 17px}.local-badge{display:none}.page-title{align-items:flex-start}.edition{display:none}.hero{display:block}.hero-copy{padding:25px}.hero h2{font-size:29px}.hero-diagram{margin:0 30px 25px;padding-top:45px;min-height:245px}.hero-blocks{height:42px}.section-heading span{display:none}.home-cards,.two-columns,.three-columns{grid-template-columns:1fr}.feature-card{padding:22px}.feature-card p{font-size:12px}.card-meta{display:flex}.card-meta span{margin:0}.hero-copy small{margin-bottom:0}.home-bottom a{margin-left:38px}.home-bottom p{font-size:11px}.card{padding:23px}.quiz-layout,.lab-layout{grid-template-columns:1fr}.question-map{display:none}.quiz-card h2{font-size:22px}.context-card .step-list{display:flex;overflow:auto;gap:15px;margin:20px 0 0}.step-list li{white-space:nowrap;gap:6px}.context-card .muted{display:none}.context-card h2{margin-bottom:0}.lab-work{padding:22px}.challenge-card{padding:22px}.challenge-tabs{gap:5px}.challenge-tabs a{padding:10px 5px}.mini-steps{gap:12px;font-size:10px}.diagram-choices{grid-template-columns:1fr}.diagram-choice .segments{max-width:270px}.diagram-choice .bar-label{max-width:270px}.diagram-choice{text-align:left}.report-summary{gap:25px}.report-summary p{font-size:11px}.dimension-results{grid-template-columns:repeat(2,1fr)}.dimension-results .card{margin-bottom:0}.dimension-results{margin-bottom:22px}.parent-tips{font-size:13px}.bottom-actions button{padding:11px 12px;font-size:12px}footer{padding:15px 17px;display:block}footer span{display:block;margin-top:5px}.calculator summary span{display:block;margin-left:0}.choices{flex-direction:column}.equation{font-size:16px}.page-title .primary{font-size:11px;padding:10px}.empty{padding:30px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
.segments.compact{gap:1px}.segments.compact .segment{font-size:0}

.skip-link:not(:focus){clip-path:inset(50%);width:1px;height:1px;overflow:hidden;top:0}

/* Guided demonstrations sit before optional diagnostics. */
.optional-assessment{display:flex;align-items:center;justify-content:space-between;gap:25px;border:1px dashed #cbd7c5;border-radius:10px;padding:20px 24px;margin-top:23px;background:#f1f4eb}.optional-assessment strong{font-size:14px}.optional-assessment p{margin:7px 0 0;font-size:12px;color:#72826b}.optional-assessment a{white-space:nowrap}.lab-coach-link{font-size:13px;padding:13px 17px;background:#eaf0e4;border-radius:7px}.lab-coach-link a{font-weight:650;color:#315c37}.explore-topics{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:23px}.explore-topics a{background:#fffefa;border:1px solid var(--border);padding:15px 16px;border-radius:8px;font-size:13px;line-height:1.8}.explore-topics a span{display:block;font:22px Georgia;color:#8aa180;margin-bottom:3px}.explore-topics a.active{background:#e4eedc;border-color:#6f9164;color:#274f30}.exploration-card{padding:30px}.exploration-top{display:flex;justify-content:space-between;gap:20px;align-items:start;padding-bottom:20px;border-bottom:1px solid #e2e9dc;margin-bottom:24px}.exploration-question{margin:13px 0 0;font-size:16px;font-weight:550;max-width:560px}.explore-mode{display:flex;padding:4px;background:#eff3e9;border:1px solid #dfe6d7;border-radius:8px;flex-shrink:0}.mode-button{border:0;background:transparent;padding:10px 13px;border-radius:5px;min-height:44px;font-size:12px;color:#6d8264;white-space:nowrap}.mode-button.active{background:white;box-shadow:0 1px 4px #253d2410;color:#244f30;font-weight:650}.demo-visual{background:#f0f4e9;background-image:radial-gradient(#91ad7c25 .9px,transparent .9px);background-size:18px 18px;padding:26px 32px;border:1px solid #e1e8d8;border-radius:10px}.demo-visual h2{font-size:25px;margin-bottom:18px}.demo-drawing{min-height:175px;display:flex;flex-direction:column;justify-content:center;max-width:820px;margin:0 auto}.explore-row{margin:16px 0}.explore-label{display:flex;justify-content:space-between;align-items:center;font-size:13px;margin-bottom:12px;gap:15px}.explore-label strong{font-size:17px;color:#456e40}.explore-track{display:grid;grid-template-columns:repeat(var(--parts),minmax(0,1fr));gap:5px}.explore-piece{background:#e7ecdf;border:1px solid #b4c6a6;color:#78916a;min-width:0;min-height:70px;display:flex;align-items:center;justify-content:center;border-radius:5px;padding:10px;font-size:15px}.explore-piece.lit{background:#60886a;border-color:#53795a;color:#fff}.explore-piece.ghost{border:2px dashed #a7b69d;color:#8fa081;background:#f4f6ee}.explore-piece.extra{background:#d5a568;border-color:#bf955c;color:#fff}.counting-dots{display:flex;flex-wrap:wrap;gap:9px;align-items:center;justify-content:center}.counting-dots i{display:block;width:23px;height:23px;border-radius:50%;background:#8da780;border:1px solid #728d66}.lit .counting-dots i{background:#faf7d8;border:1px solid #e9e2b3;box-shadow:inset -2px -2px #d0c99e60}.diagram-caption{font-size:12px;color:#7b8b70;text-align:center;margin:17px 0}.explore-equation{padding:18px 20px;background:#fffef5;border:1px solid #dce4d0;border-radius:8px;color:#365b34;font-size:20px;line-height:1.9;margin:20px 0 0;overflow-wrap:anywhere}.explore-equation.placeholder{font-size:13px;color:#9aa68d;background:transparent;border:1px dashed #d4dec8}.narration{display:flex;gap:18px;padding:23px 10px 12px;align-items:flex-start}.narrator-mark{background:#e6ddc6;color:#89703d;border-radius:50%;min-width:40px;height:40px;display:flex;align-items:center;justify-content:center;font-size:15px}.narration strong{font-size:13px;color:#8a916f}.narration p{font-size:17px;line-height:1.95;margin:9px 0 0;color:#354d36}.demo-controls{padding:18px 0;border-top:1px solid #e4eadc;margin-top:13px}.demo-controls p{font-size:12px;color:#849278;margin:13px 0 0}.demo-handoff{border-top:1px solid #e4eadc;padding-top:20px;display:flex;justify-content:space-between;align-items:center;gap:15px}.demo-handoff>span{font-size:13px;color:#78876c}.playground-heading h2{font-size:25px;margin:15px 0 5px}.playground-controls{display:flex;align-items:center;flex-wrap:wrap;gap:15px 25px}.playground-controls label{flex:1;min-width:200px}.playground-controls select{max-width:240px}.playground-controls>button{align-self:center}.discovery-hint{font-size:15px;background:#f4f1df;border-left:3px solid #d1b76a;border-radius:4px;padding:15px 18px;margin:20px 0 25px}.discovery-hint.matched{background:#eaf2df;border-color:#89a46b}.reflection{max-width:800px;padding:15px 0}.reflection>p{font-size:16px}.reflection textarea{min-height:140px}.reflection .text-link{margin:15px;display:inline-block}.explore-footnote{font-size:12px}.exploration-card #explore-model{padding:5px 0}.exploration-card .actions{gap:9px}
@media(max-width:1150px){.exploration-top{flex-direction:column}.explore-topics a{font-size:12px;padding:12px}.narration p{font-size:16px}.explore-equation{font-size:18px}.demo-visual{padding:24px}.explore-piece{padding:8px;font-size:13px}}
@media(max-width:620px){.explore-topics{grid-template-columns:repeat(2,1fr)}.exploration-card{padding:20px}.explore-mode{width:100%}.mode-button{flex:1;padding:9px}.demo-visual{padding:17px}.demo-visual h2,.playground-heading h2{font-size:21px}.counting-dots{gap:5px}.counting-dots i{width:16px;height:16px}.explore-piece{padding:5px;min-height:58px;font-size:11px}.narration{gap:11px;padding:20px 0}.narration p{font-size:15px}.narrator-mark{min-width:33px;height:33px;font-size:12px}.narration strong{font-size:12px}.explore-equation{font-size:15px;padding:13px}.demo-controls .actions button{padding:9px 11px;font-size:12px}.demo-handoff{flex-direction:column;align-items:stretch}.demo-handoff .primary{width:100%}.optional-assessment{flex-direction:column;align-items:start;padding:20px}.optional-assessment .primary{width:100%}.explore-label{font-size:11px}.explore-label strong{font-size:13px}.exploration-question{font-size:15px}.discovery-hint{font-size:13px}.sidebar nav{scrollbar-width:thin}}

.math-animation{width:100%;height:auto;display:block;overflow:visible}.animated-lesson .demo-drawing{max-width:none;min-height:0}.animated-lesson h2{margin-bottom:0}.motion-label{font:17px "Microsoft YaHei",sans-serif;fill:#4c6840}.motion-known{font:bold 22px "Microsoft YaHei",sans-serif;fill:#45683e}.motion-part-text{font:20px "Microsoft YaHei",sans-serif}.motion-dot{stroke:#e4dfb5;stroke-width:1}.motion-takeaway{font:18px "Microsoft YaHei",sans-serif;fill:#527344}.voice-caption{background:#fffdf4;border:1px solid #e2e4d2;border-radius:8px;text-align:center;padding:16px 22px;font-size:18px;line-height:1.85;min-height:69px;color:#284e34}.voice-caption mark{background:#e3e9a5;color:inherit;border-radius:3px}.audio-controls{display:flex;align-items:center;gap:25px;padding:6px 0 12px}.audio-seek-label{flex:1;font-size:12px;color:#718367;margin:15px 0}.audio-seek-label>span{float:right;font-variant-numeric:tabular-nums}.audio-seek-label input[type=range]{margin:7px 0 0}.audio-options{display:flex;align-items:center;gap:14px}.audio-options label{font-size:10px;margin:0;color:#829176}.audio-options select{font-size:12px;padding:7px 10px;min-height:36px;margin-top:3px}.audio-options button{font-size:12px;min-width:70px;padding:10px}.narration-transcript{display:block;padding:16px 0;border-top:1px solid #e3e8da;font-size:13px;color:#7b8b71}.narration-transcript p{font-size:15px}.narration-transcript summary{font-size:12px}.animated-lesson .explore-equation{margin-top:14px;font-size:18px}.animated-lesson{padding:20px 26px}.demo-handoff{margin-top:8px}
@media(max-width:620px){.audio-controls{flex-wrap:wrap;gap:0}.audio-seek-label{flex-basis:100%}.audio-options{width:100%;justify-content:space-between;margin-bottom:10px}.voice-caption{font-size:15px;padding:12px;min-height:70px}.animated-lesson{padding:16px 12px}.animated-lesson .explore-equation{font-size:14px}.animated-lesson h2{font-size:19px}.motion-label{font-size:23px}.motion-known{font-size:25px}.motion-part-text{font-size:27px}.motion-takeaway{font-size:23px}}