.learning-path,.learning-workshop{color:var(--text-primary)}.learning-path{border-bottom:1px solid var(--border-subtle);padding:24px}.learning-path p,.learning-workshop p{line-height:1.8}.learning-path-grid{grid-template-columns:repeat(auto-fit,minmax(min(100%,280px),1fr));gap:16px;display:grid}.learning-path article,.prediction-exercise,.learning-project-card{border:1px solid var(--border-subtle);background:var(--bg-secondary);border-radius:12px;padding:20px}.learning-path h4{margin:0 0 12px}.learning-actions{flex-wrap:wrap;gap:10px;margin:16px 0;display:flex}.learning-workshop input:not([type=checkbox]):not([type=range]),.learning-workshop textarea,.learning-workshop select{box-sizing:border-box;border:1px solid var(--border-subtle);background:var(--bg-primary);width:100%;max-width:100%;color:var(--text-primary);font:inherit;border-radius:8px;margin:8px 0 16px;padding:12px;display:block}.learning-workshop textarea{resize:vertical;min-height:100px}.learning-workshop label{line-height:1.6;display:block}.learning-workshop button:disabled{opacity:.55;cursor:not-allowed}.learning-workshop :focus-visible,.learning-path :focus-visible{outline:2px solid var(--accent-cyan);outline-offset:3px}.learning-method{border-left:3px solid var(--accent-cyan);background:var(--bg-secondary);margin:16px 0;padding:16px}.learning-method summary{cursor:pointer;font-weight:600}.learning-method li{margin:10px 0}.learning-note,.prediction-feedback{background:var(--bg-primary);border-left:3px solid var(--accent-cyan);margin-top:16px;padding:16px}.learning-workshop .learning-check{align-items:start;gap:10px;margin:12px 0;display:flex}.learning-check input{flex-shrink:0;margin-top:6px}.learning-workshop svg{width:100%;height:auto;color:var(--text-primary);display:block}.learning-workshop .project-readouts{grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:12px;display:grid}.learning-workshop .project-readouts output{border:1px solid var(--border-subtle);border-radius:8px;padding:12px;display:block}.learning-workshop .project-readouts strong{color:var(--accent-cyan);font-size:1.25rem;display:block}.learning-workshop .project-table-wrap{overflow-x:auto}.learning-workshop table{border-collapse:collapse;width:100%}.learning-workshop th,.learning-workshop td{text-align:left;border-bottom:1px solid var(--border-subtle);vertical-align:top;padding:10px}.learning-workshop .project-record{grid-template-columns:repeat(auto-fit,minmax(min(100%,200px),1fr));gap:12px;display:grid}@media (width<=480px){.learning-path,.learning-path article,.prediction-exercise,.learning-project-card{padding:14px}.learning-actions button{white-space:normal}}.catalog-learning-body{min-height:0;overflow-y:auto}.catalog-learning-body .catalog-grid{overflow:visible}:is(.catalog-modal:has(.catalog-learning-body)>.catalog-modal-header,.catalog-modal:has(.catalog-learning-body)>.catalog-search-bar){flex-shrink:0}.lesson-ampere .amp-takeaway{border-left:3px solid var(--text-primary);background:var(--bg-secondary);color:var(--text-primary);margin:1.5rem 0;padding:1.1rem 1.3rem;line-height:1.85}.lesson-ampere .amp-lab{margin:1.5rem 0;padding:1.4rem}.lesson-ampere .amp-lab .lab-header{flex-wrap:wrap;margin-bottom:1rem;padding:0 0 1rem}.lesson-ampere .amp-controls{flex-wrap:wrap;align-items:center;gap:.7rem;margin:1rem 0;display:flex}.lesson-ampere .amp-controls button{min-height:44px}.lesson-ampere .amp-controls button[aria-pressed=true]{background:var(--text-primary);color:var(--bg-primary);border-color:var(--text-primary)}.lesson-ampere .amp-controls input{min-width:100px;max-width:340px;accent-color:var(--text-primary);flex:1}.lesson-ampere .amp-controls output{font-variant-numeric:tabular-nums;min-width:4rem}.lesson-ampere .amp-readout{border-top:1px solid var(--border-subtle);color:var(--text-primary);font-variant-numeric:tabular-nums;padding-top:1rem;line-height:1.85}.lesson-ampere .amp-note,.lesson-ampere .amp-source{font-size:.9rem}.lesson-ampere .amp-units{background:var(--bg-secondary);color:var(--text-primary);font-variant-numeric:tabular-nums;flex-wrap:wrap;gap:.8rem 2rem;margin:1rem 0;padding:1rem;display:flex}.lesson-ampere .amp-detail{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);margin:1.5rem 0;padding:1rem 1.2rem}.lesson-ampere .amp-detail summary{cursor:pointer;color:var(--text-primary);font-weight:600;line-height:1.7}.lesson-ampere .amp-detail p{margin:1rem 0 0}.lesson-ampere .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-ampere button:focus-visible,.lesson-ampere input:focus-visible,.lesson-ampere summary:focus-visible{outline:2px solid var(--text-primary);outline-offset:4px}@media (width<=600px){.lesson-ampere .amp-lab{padding:1rem}}.lesson-ampere .math-formula-body{color:var(--text-primary)}.lesson-ampere .math-formula-body>span:not(.math-highlight){margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-ampere .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-ampere .math-subtext{color:var(--text-secondary)}.lesson-ampere .micro-atom-layout{grid-template-columns:minmax(230px,1fr) 1fr;align-items:center;gap:1.5rem;display:grid}.lesson-ampere .micro-atom-description h3{margin:0 0 1rem;font-size:1.2rem}.lesson-ampere .micro-force-pair{text-align:center;grid-template-columns:1fr 1fr;gap:1rem;padding-top:1rem;display:grid}.lesson-ampere .micro-force-pair>span{background:var(--bg-secondary);color:var(--text-primary);padding:1rem .5rem;font-size:1.3rem}.lesson-ampere .micro-force-pair small{color:var(--text-secondary);margin-top:.6rem;font-size:.85rem;display:block}@media (width<=600px){.lesson-ampere .micro-atom-layout{grid-template-columns:1fr;gap:.5rem}}.lesson-ampere .amp-meter-text{background:var(--bg-secondary);color:var(--text-primary);font-variant-numeric:tabular-nums;margin:.6rem 0;padding:.7rem 1rem;line-height:1.7}.lesson-ampere .amp-meter{color:var(--text-secondary);align-items:center;gap:.8rem;margin:.6rem 0;font-size:.9rem;display:flex}.lesson-ampere .amp-meter-track{border:1px solid var(--border-subtle);background:var(--bg-secondary);border-radius:6px;flex:1;height:12px;overflow:hidden}.lesson-ampere .amp-meter-fill{background:#e0a526;width:0;height:100%}.lesson-ampere .amp-meter-fill[data-hot=true]{background:#e5484d}.three-stage{aspect-ratio:2;border:1px solid var(--border-subtle);background:var(--bg-secondary);border-radius:6px;width:100%;margin:1.2rem 0;position:relative;overflow:hidden}.three-stage.is-square{aspect-ratio:1;margin:0}.three-stage.is-tall{aspect-ratio:1.5}.three-stage-mount{position:absolute;inset:0}.three-stage-canvas{cursor:grab;width:100%;height:100%;display:block}.three-stage-canvas:active{cursor:grabbing}.three-stage-labels{pointer-events:none;position:absolute;inset:0;overflow:hidden}.three-label{white-space:nowrap;color:var(--text-primary);background:color-mix(in srgb, var(--bg-card) 80%, transparent);font-variant-numeric:tabular-nums;border-radius:4px;padding:1px 7px;font-size:.82rem;line-height:1.5}.three-label.is-focus{outline:2px solid var(--text-primary);outline-offset:1px}.three-label.is-quiet{color:var(--text-secondary)}.three-label.is-sign{background:0 0;padding:0;font-size:1.25rem;font-weight:700}.three-stage-hint{color:var(--text-muted);pointer-events:none;font-size:.72rem;animation:1s 7s forwards three-hint-fade;position:absolute;bottom:6px;right:8px}.three-stage-status{text-align:center;color:var(--text-secondary);place-items:center;margin:0;padding:1rem;font-size:.9rem;display:grid;position:absolute;inset:0}@media (width<=600px){.three-stage{aspect-ratio:1.6}.three-stage.is-square{aspect-ratio:1.15}.three-stage.is-tall{aspect-ratio:1.05}.three-label{padding:0 5px;font-size:.74rem}}@keyframes three-hint-fade{to{opacity:0;visibility:hidden}}.lesson-voltage .volt-takeaway{border-left:3px solid var(--text-primary);background:var(--bg-secondary);color:var(--text-primary);margin:1.5rem 0;padding:1.1rem 1.3rem;line-height:1.85}.lesson-voltage .volt-lab{margin:1.5rem 0;padding:1.4rem}.lesson-voltage .volt-lab .lab-header{flex-wrap:wrap;margin-bottom:1rem;padding:0 0 1rem}.lesson-voltage .volt-controls{color:var(--text-primary);flex-wrap:wrap;align-items:center;gap:.7rem;margin:1rem 0;display:flex}.lesson-voltage .volt-controls button,.lesson-voltage select{min-height:44px}.lesson-voltage .volt-controls button[aria-pressed=true]{background:var(--text-primary);color:var(--bg-primary);border-color:var(--text-primary)}.lesson-voltage .volt-slider{color:var(--text-primary);flex-wrap:wrap;align-items:center;gap:1rem;margin:1.2rem 0;display:flex}.lesson-voltage .volt-slider>span{flex:0 0 9rem}.lesson-voltage .volt-slider input{min-width:100px;accent-color:var(--text-primary);flex:1}.lesson-voltage .volt-slider output{font-variant-numeric:tabular-nums;min-width:4.5rem}.lesson-voltage select{background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border-subtle);font:inherit;border-radius:4px;padding:.4rem .8rem}.lesson-voltage .volt-readout{border-top:1px solid var(--border-subtle);color:var(--text-primary);font-variant-numeric:tabular-nums;padding-top:1rem;line-height:1.85}.lesson-voltage .volt-note{font-size:.9rem}.lesson-voltage .volt-detail{border:1px solid var(--border-subtle);border-radius:5px;margin:1.4rem 0 0;padding:1rem}.lesson-voltage .volt-detail summary{cursor:pointer;color:var(--text-primary);font-weight:600;line-height:1.7}.lesson-voltage .volt-detail p{margin:1rem 0 0}.lesson-voltage .volt-comparison{grid-template-columns:1fr 1fr;gap:1rem;margin:1.5rem 0;display:grid}.lesson-voltage .volt-comparison>div{border:1px solid var(--border-subtle);border-radius:5px;padding:1.2rem}.lesson-voltage .volt-comparison h3{margin:0 0 .6rem;font-size:1.1rem}.lesson-voltage .volt-comparison p{margin:0}.lesson-voltage .volt-story{counter-reset:stages;gap:.7rem;margin:1.5rem 0;display:grid}.lesson-voltage .volt-story>span{counter-increment:stages;background:var(--bg-secondary);color:var(--text-primary);padding:1rem}.lesson-voltage .volt-story>span:before{content:"0" counter(stages) "　";font-variant-numeric:tabular-nums;color:var(--text-secondary)}.lesson-voltage .volt-story small{color:var(--text-secondary);margin:.5rem 0 0 2.3rem;display:block}.lesson-voltage .math-formula-body{color:var(--text-primary)}.lesson-voltage .math-formula-body>span{margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-voltage .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-voltage .math-subtext{color:var(--text-secondary)}.lesson-voltage .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-voltage button:focus-visible,.lesson-voltage input:focus-visible,.lesson-voltage select:focus-visible,.lesson-voltage summary:focus-visible{outline:2px solid var(--text-primary);outline-offset:4px}@media (width<=600px){.lesson-voltage .volt-lab{padding:1rem}.lesson-voltage .volt-comparison{grid-template-columns:1fr}.lesson-voltage .volt-slider{gap:.6rem}.lesson-voltage .volt-slider>span{flex:0 0 100%}}.lesson-voltage .volt-meter-text{background:var(--bg-secondary);color:var(--text-primary);font-variant-numeric:tabular-nums;margin:.6rem 0;padding:.7rem 1rem;line-height:1.7}.lesson-voltage .volt-meter{color:var(--text-secondary);align-items:center;gap:.8rem;margin:.6rem 0;font-size:.9rem;display:flex}.lesson-voltage .volt-meter-track{border:1px solid var(--border-subtle);background:var(--bg-secondary);border-radius:6px;flex:1;height:12px;overflow:hidden}.lesson-voltage .volt-meter-fill{background:#e0a526;width:0;height:100%}.lesson-voltage .three-label.is-meter{padding:2px 10px;font-size:1.15rem;font-weight:700}.lesson-voltage .volt-list{color:var(--text-secondary);margin:1rem 0 1rem 1.4rem;line-height:1.9}.lesson-voltage .volt-list li{margin:.3rem 0}.lab3d-takeaway{border-left:3px solid var(--text-primary);background:var(--bg-secondary);color:var(--text-primary);margin:1.5rem 0;padding:1.1rem 1.3rem;line-height:1.85}.lab3d{margin:1.5rem 0;padding:1.4rem}.lab3d .lab-header{flex-wrap:wrap;margin-bottom:1rem;padding:0 0 1rem}.lab3d-controls{color:var(--text-primary);flex-wrap:wrap;align-items:center;gap:.7rem;margin:1rem 0;display:flex}.lab3d-controls button,.lab3d select{min-height:44px}.lab3d-controls button[aria-pressed=true]{background:var(--text-primary);color:var(--bg-primary);border-color:var(--text-primary)}.lab3d-slider{color:var(--text-primary);flex-wrap:wrap;align-items:center;gap:1rem;margin:1.2rem 0;display:flex}.lab3d-slider>span{flex:0 0 9rem}.lab3d-slider input{min-width:100px;accent-color:var(--text-primary);flex:1}.lab3d-slider output{font-variant-numeric:tabular-nums;min-width:5rem}.lab3d select{background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border-subtle);font:inherit;border-radius:4px;padding:.4rem .8rem}.lab3d-readout{border-top:1px solid var(--border-subtle);color:var(--text-primary);font-variant-numeric:tabular-nums;padding-top:1rem;line-height:1.85}.lab3d-note{font-size:.9rem}.lab3d-meter-text{background:var(--bg-secondary);color:var(--text-primary);font-variant-numeric:tabular-nums;margin:.6rem 0;padding:.7rem 1rem;line-height:1.7}.lab3d-meter{color:var(--text-secondary);align-items:center;gap:.8rem;margin:.6rem 0;font-size:.9rem;display:flex}.lab3d-meter-track{border:1px solid var(--border-subtle);background:var(--bg-secondary);border-radius:6px;flex:1;height:12px;overflow:hidden}.lab3d-meter-fill{background:#e0a526;width:0;height:100%}.lab3d-meter-fill[data-hot=true]{background:#e5484d}.lab3d button:focus-visible,.lab3d input:focus-visible,.lab3d select:focus-visible{outline:2px solid var(--text-primary);outline-offset:4px}.lesson-detail{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);margin:1.5rem 0;padding:1rem 1.2rem}.lesson-detail summary{cursor:pointer;color:var(--text-primary);font-weight:600;line-height:1.7}.lesson-detail p{margin:1rem 0 0}@media (width<=600px){.lab3d{padding:1rem}.lab3d-slider{gap:.6rem}.lab3d-slider>span{flex:0 0 100%}}.lab3d-list{color:var(--text-secondary);margin:1rem 0 1rem 1.4rem;line-height:1.9}.lab3d-list li{margin:.3rem 0}.lesson-ohm .ohm-list{color:var(--text-secondary);margin:1rem 0 1rem 1.4rem;line-height:1.9}.lesson-ohm .ohm-list li{margin:.3rem 0}.lesson-ohm .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-ohm .math-formula-body{color:var(--text-primary)}.lesson-ohm .math-formula-body>span:not(.math-highlight){margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-ohm .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-ohm .math-subtext{color:var(--text-secondary)}.lesson-watt .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-watt .math-formula-body{color:var(--text-primary)}.lesson-watt .math-formula-body>span:not(.math-highlight){margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-watt .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-watt .math-subtext{color:var(--text-secondary)}.lesson-led .led-comparison{flex-wrap:wrap;gap:1rem;margin:1.5rem 0;display:flex}.lesson-led .led-comparison>div{border:1px solid var(--border-color,#777);background:var(--bg-card);border-radius:12px;flex:180px;min-width:0;padding:1rem}.lesson-led .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-led .math-formula-body{color:var(--text-primary)}.lesson-led .math-formula-body>span{margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-led .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-led .math-subtext{color:var(--text-secondary)}.lesson-shock .shock-takeaway{border-left:3px solid var(--text-primary);background:var(--bg-secondary);color:var(--text-primary);margin:1.5rem 0;padding:1.1rem 1.3rem;line-height:1.85}.lesson-shock .shock-factors,.lesson-shock .shock-compare{grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin:1.5rem 0;display:grid}.lesson-shock .shock-factors>div,.lesson-shock .shock-compare>div{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);padding:1.2rem}.lesson-shock .shock-factors b{font-size:1.1rem}.lesson-shock .shock-factors p,.lesson-shock .shock-compare p{margin:.6rem 0 0}.lesson-shock .shock-compare h3{margin:0 0 1rem;font-size:1.1rem}.lesson-shock .shock-flow{color:var(--text-primary);font-weight:600;line-height:1.8}.lesson-shock .shock-lab{margin:1.5rem 0;padding:1.4rem}.lesson-shock .shock-lab .lab-header{flex-wrap:wrap;margin-bottom:1rem;padding:0 0 1rem}.lesson-shock .shock-controls{flex-wrap:wrap;align-items:center;gap:.7rem;margin:1rem 0;display:flex}.lesson-shock .shock-controls button{min-height:44px}.lesson-shock .shock-controls button[aria-pressed=true]{color:var(--bg-primary);background:var(--text-primary);border-color:var(--text-primary)}.lesson-shock .shock-controls input{min-width:100px;max-width:340px;accent-color:var(--text-primary);flex:1}.lesson-shock .shock-controls output{font-variant-numeric:tabular-nums;min-width:4rem}.lesson-shock .shock-wave{width:100%;max-width:740px;height:auto;margin:1rem auto;display:block}.lesson-shock .shock-wave text{fill:var(--text-secondary);font-size:15px}.lesson-shock .shock-axis{fill:none;stroke:var(--text-secondary);stroke-width:1.5px}.lesson-shock .shock-guide{fill:none;stroke:var(--text-secondary);stroke-dasharray:4 5;opacity:.5}.lesson-shock .shock-area{fill:var(--text-primary);opacity:.1}.lesson-shock .shock-line{fill:none;stroke:var(--text-primary);stroke-width:3px;stroke-linejoin:round}.lesson-shock .shock-readout{border-top:1px solid var(--border-subtle);font-variant-numeric:tabular-nums;color:var(--text-primary);padding:1rem 0;line-height:1.9}.lesson-shock .shock-note{margin-bottom:0;font-size:.9rem}.lesson-shock .shock-circuit{background:var(--bg-secondary);text-align:center;justify-content:space-around;align-items:center;gap:.5rem;margin:1.2rem 0;padding:1.2rem .5rem;line-height:1.8;display:flex}.lesson-shock .shock-detail{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);margin:1.5rem 0;padding:1rem 1.2rem}.lesson-shock .shock-detail summary{cursor:pointer;color:var(--text-primary);font-weight:600;line-height:1.7}.lesson-shock .shock-detail p{margin:1rem 0 0}.lesson-shock .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-shock button:focus-visible,.lesson-shock input:focus-visible,.lesson-shock summary:focus-visible{outline:2px solid var(--text-primary);outline-offset:4px}@media (width<=600px){.lesson-shock .shock-factors,.lesson-shock .shock-compare{grid-template-columns:1fr}.lesson-shock .shock-lab{padding:1rem}.lesson-shock .shock-circuit{font-size:.85rem}.lesson-shock .shock-wave text{font-size:17px}}.lesson-shock .micro-canvas{aspect-ratio:2;border-radius:var(--radius-sm);width:100%;height:auto;margin:1rem 0;display:block}.lesson-shock .lesson-next-bridge-card{flex-wrap:wrap}.lesson-shock .shock-readout{overflow-wrap:anywhere}.lesson-fet .fet-grid{flex-wrap:wrap;gap:1rem;margin:1.5rem 0;display:flex}.lesson-fet .fet-grid>div{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);background:var(--bg-secondary);flex:180px;min-width:0;padding:1rem}.lesson-fet .fet-controls{flex-wrap:wrap;align-items:center;gap:.7rem;margin:1rem 0;display:flex}.lesson-fet .fet-controls button{min-height:44px}.lesson-fet .fet-controls [aria-pressed=true]{outline:2px solid var(--accent-cyan);outline-offset:2px}.lesson-fet .fet-lab{padding:clamp(.8rem,3vw,1.5rem)}.lesson-fet .fet-lab .lab-header{flex-wrap:wrap}.lesson-fet .fet-lab label{flex-wrap:wrap;align-items:center;gap:.8rem;display:flex}.lesson-fet .fet-lab input{min-width:0;accent-color:var(--accent-cyan);flex:140px}.lesson-fet .micro-canvas{aspect-ratio:2;width:100%;height:auto;margin:1rem 0;display:block}.lesson-fet .fet-readout{font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.lesson-fet .fet-note{color:var(--text-secondary)}.lesson-fet .fet-wiring,.lesson-fet .fet-detail{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);margin:1rem 0;padding:1rem}.lesson-fet .fet-detail summary{cursor:pointer}.lesson-fet .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-fet .lesson-next-bridge-card{flex-wrap:wrap}.lesson-capacitor .cap-grid{flex-wrap:wrap;gap:1rem;margin:1.5rem 0;display:flex}.lesson-capacitor .cap-grid>div{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);flex:180px;min-width:0;padding:1rem}.lesson-capacitor .cap-verdict{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);margin:1rem 0;padding:1rem}.lesson-capacitor .cap-part{text-align:center;background:var(--bg-secondary);padding:1rem}.lesson-capacitor .cap-can{border:2px solid var(--text-secondary);border-radius:10px;justify-content:space-between;align-items:center;gap:1rem;max-width:260px;margin:auto;padding:.5rem;display:flex}.lesson-capacitor .cap-can strong{padding:.5rem}.lesson-capacitor .cap-stripe{background:var(--text-primary);color:var(--bg-primary);padding:.25rem .5rem}.lesson-capacitor .cap-reversed{flex-direction:row-reverse}.lesson-capacitor .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-capacitor .math-formula-body{color:var(--text-primary)}.lesson-capacitor .math-formula-body>span{margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-capacitor .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-capacitor .math-subtext{color:var(--text-secondary)}.lesson-capacitor .cap-verdict ul{margin:0 0 0 1.2rem;line-height:1.8}.lesson-scope .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-scope .lesson-next-bridge-card{flex-wrap:wrap}.lesson-divider .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-divider .math-formula-body{color:var(--text-primary)}.lesson-divider .math-formula-body>span:not(.math-highlight){margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-divider .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-divider .math-subtext{color:var(--text-secondary)}.circuit-course .circuit-lab{border:1px solid var(--border-subtle);background:var(--bg-secondary);border-radius:8px;margin:1.7rem 0;padding:1.25rem}.circuit-course .circuit-lab h3{color:var(--text-primary);margin:0 0 .65rem;font-size:1.15rem}.circuit-course .circuit-lab p{font-size:.95rem;line-height:1.85}.circuit-course .micro-canvas{aspect-ratio:2;border:1px solid var(--border-subtle);border-radius:5px;width:100%;height:auto;margin:1rem 0;display:block}.circuit-course .circuit-slider{margin:1rem 0;display:block}.circuit-course .circuit-slider>span{flex-wrap:wrap;justify-content:space-between;gap:.5rem;display:flex}.circuit-course .circuit-slider output{font-variant-numeric:tabular-nums;color:var(--text-primary)}.circuit-course .circuit-slider input{width:100%;min-height:32px;accent-color:var(--text-primary)}.circuit-course .circuit-choices{border:0;flex-wrap:wrap;gap:.5rem;min-width:0;margin:1rem 0;padding:0;display:flex}.circuit-course .circuit-choices legend{margin-bottom:.5rem}.circuit-course .circuit-actions{flex-wrap:wrap;gap:.5rem;margin-top:.8rem;display:flex}.circuit-course .circuit-lab button{background:var(--bg-card);border:1px solid var(--border-active);min-height:44px;color:var(--text-primary);cursor:pointer;font:inherit;border-radius:5px;padding:.6rem .9rem}.circuit-course .circuit-lab button[aria-pressed=true]{background:var(--text-primary);color:var(--bg-primary)}.circuit-course button:focus-visible,.circuit-course input:focus-visible{outline-offset:3px;outline:3px solid #0284c7}.circuit-course .circuit-readouts{grid-template-columns:repeat(auto-fit,minmax(135px,1fr));gap:.65rem;margin:1rem 0;display:grid}.circuit-course .circuit-readouts>div{background:var(--bg-card);border:1px solid var(--border-subtle);padding:.8rem}.circuit-course .circuit-readouts span{color:var(--text-secondary);font-size:.8rem;display:block}.circuit-course .circuit-readouts strong{color:var(--text-primary);font-variant-numeric:tabular-nums;font-size:1.05rem;display:block}.circuit-course .circuit-boundary{color:var(--text-secondary);border-top:1px solid var(--border-subtle);padding-top:.8rem}.circuit-course .circuit-chain{border:1px solid var(--border-subtle);margin:1.4rem 0;padding:1.1rem}.circuit-course .circuit-chain figcaption{color:var(--text-secondary);margin-bottom:1rem;font-size:.85rem}.circuit-course .circuit-chain ol{counter-reset:stage;flex-wrap:wrap;gap:.8rem;margin:0;padding:0;list-style:none;display:flex}.circuit-course .circuit-chain li{border-left:2px solid var(--border-active);counter-increment:stage;flex:150px;padding:.35rem .8rem}.circuit-course .circuit-chain strong:before{content:counter(stage) " · "}.circuit-course .circuit-chain span{margin-top:.5rem;font-size:.9rem;line-height:1.7;display:block}.circuit-course .circuit-equation{background:var(--bg-secondary);border-left:3px solid var(--border-active);overflow-wrap:anywhere;margin:1.2rem 0;padding:1rem;line-height:1.9}.circuit-course .circuit-equation strong{margin-bottom:.4rem;font-size:1.15rem;display:block}.circuit-course .circuit-source{color:var(--text-secondary);font-size:.85rem}.circuit-course .circuit-source a{text-decoration:underline}.circuit-course .circuit-prerequisite{border-left:2px solid var(--border-active);padding:1rem;line-height:1.8}.circuit-course .circuit-schematic{width:100%;height:auto;color:var(--text-primary);background:var(--bg-secondary);margin:1rem 0}@media (width<=600px){.circuit-course .circuit-lab{padding:.8rem}.circuit-course .micro-canvas{aspect-ratio:1.65}.circuit-course .circuit-readouts{grid-template-columns:1fr 1fr}.circuit-course .circuit-chain ol{flex-direction:column}.circuit-course .circuit-chain li{flex:auto}}.lesson-scope-use .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-scope-use .lesson-next-bridge-card{flex-wrap:wrap}.lesson-lowpass .section-narrative a{color:var(--text-primary);text-underline-offset:3px;text-decoration:underline}.lesson-lowpass .math-formula-body{color:var(--text-primary)}.lesson-lowpass .math-formula-body>span:not(.math-highlight){margin-top:.6rem;font-size:1.05rem;line-height:1.8;display:inline-block}.lesson-lowpass .math-formula-tag{color:var(--text-secondary);background:var(--bg-secondary)}.lesson-lowpass .math-subtext{color:var(--text-secondary)}.lesson-electricity .compare-grid,.lesson-electricity .effect-grid,.lesson-electricity .resistance-factors,.lesson-electricity .wave-compare{gap:1rem;margin:1.4rem 0;display:grid}.lesson-electricity .compare-grid,.lesson-electricity .wave-compare{grid-template-columns:repeat(2,minmax(0,1fr))}.lesson-electricity .effect-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.lesson-electricity .resistance-factors{grid-template-columns:repeat(4,minmax(0,1fr))}.lesson-electricity .compare-card,.lesson-electricity .effect-card,.lesson-electricity .resistance-factors>div,.lesson-electricity .wave-compare>div{border:1px solid var(--border-subtle);border-radius:var(--radius-md);background:var(--bg-card);min-width:0;padding:1.1rem}.lesson-electricity .compare-card b,.lesson-electricity .effect-card b,.lesson-electricity .resistance-factors b,.lesson-electricity .wave-compare b{color:var(--text-primary);margin-bottom:.45rem;display:block}.lesson-electricity .compare-card p,.lesson-electricity .effect-card p,.lesson-electricity .wave-compare p{color:var(--text-secondary);margin:0}.lesson-electricity .resistance-factors span{color:var(--text-secondary);font-size:.9rem;display:block}.lesson-electricity .atom-stage{perspective:700px;border:1px solid var(--border-subtle);border-radius:var(--radius-lg);background:radial-gradient(circle at center, #f59e0b24, transparent 18%), radial-gradient(circle at center, #38bdf814, transparent 62%), var(--bg-secondary);place-items:center;width:min(100%,620px);min-height:280px;margin:1.5rem auto;display:grid;position:relative;overflow:hidden}.lesson-electricity .atom-nucleus{z-index:3;color:#fff;text-align:center;background:radial-gradient(circle at 35% 30%,#fb7185,#9f1239);border-radius:50%;place-items:center;width:62px;height:62px;font-weight:800;line-height:1.1;animation:2.2s ease-in-out infinite atom-pulse;display:grid;box-shadow:0 0 28px #f43f5e6b}.lesson-electricity .atom-orbit{width:310px;height:118px;transform-style:preserve-3d;border:1px solid #38bdf899;border-radius:50%;position:absolute}.lesson-electricity .atom-orbit.orbit-one{transform:rotate(18deg)rotateX(56deg)}.lesson-electricity .atom-orbit.orbit-two{transform:rotate(108deg)rotateX(56deg)}.lesson-electricity .atom-orbit i{background:var(--accent-cyan);border-radius:50%;width:16px;height:16px;margin:-8px;animation:3.2s linear infinite orbit-electron;position:absolute;top:47px;left:50%;box-shadow:0 0 14px #38bdf8bf}.lesson-electricity .orbit-two i{animation-duration:4.1s;animation-direction:reverse}.lesson-electricity .atom-label{text-align:center;color:var(--text-secondary);font-size:.86rem;position:absolute;bottom:14px;left:1rem;right:1rem}@keyframes atom-pulse{50%{transform:scale(1.08)}}@keyframes orbit-electron{to{transform:rotate(360deg)translate(150px)rotate(-360deg)}}.lesson-electricity .lesson22-lab{margin:1.6rem 0;padding:1.3rem}.lesson-electricity .lesson22-lab .lab-header{flex-wrap:wrap;padding:0 0 1rem}.lesson-electricity .micro-canvas{aspect-ratio:2;border:1px solid var(--border-subtle);border-radius:var(--radius-sm);background:var(--bg-primary);width:100%;display:block}.lesson-electricity .lesson22-controls{flex-wrap:wrap;align-items:center;gap:.65rem;margin:1rem 0;display:flex}.lesson-electricity .lesson22-controls button{min-height:44px}.lesson-electricity .lesson22-controls button[aria-pressed=true]{background:var(--text-primary);border-color:var(--text-primary);color:var(--bg-primary)}.lesson-electricity .lesson22-controls button:disabled{opacity:.45;cursor:not-allowed}.lesson-electricity .lesson22-controls input{min-width:110px;max-width:260px;accent-color:var(--accent-cyan);flex:1}.lesson-electricity .lesson22-controls output{min-width:2.6rem;color:var(--text-primary);font-variant-numeric:tabular-nums}.lesson-electricity .lesson22-readout{background:var(--bg-secondary);border-left:3px solid var(--accent-cyan);color:var(--text-primary);font-variant-numeric:tabular-nums;padding:.85rem 1rem}.lesson-electricity .model-note{color:var(--text-secondary);font-size:.9rem}.lesson-electricity .circuit-story,.lesson-electricity .transformer-flow{justify-content:space-between;align-items:stretch;gap:.6rem;margin:1.4rem 0;display:flex}.lesson-electricity .circuit-story>div,.lesson-electricity .transformer-flow>div{text-align:center;border:1px solid var(--border-subtle);border-radius:var(--radius-md);background:var(--bg-card);flex:1;min-width:0;padding:1rem .7rem}.lesson-electricity .circuit-story b,.lesson-electricity .transformer-flow b{color:var(--text-primary);display:block}.lesson-electricity .circuit-story span,.lesson-electricity .transformer-flow span{color:var(--text-secondary);font-size:.84rem;display:block}.lesson-electricity .circuit-story i,.lesson-electricity .transformer-flow i{color:var(--accent-cyan);align-self:center;font-style:normal}.lesson-electricity .direction-pair{grid-template-columns:1fr 1fr;gap:.7rem;margin:1.3rem 0;display:grid}.lesson-electricity .direction-pair span{text-align:center;border-radius:var(--radius-sm);background:var(--bg-secondary);padding:.9rem;font-weight:700}.lesson-electricity .direction-pair span:last-child{color:var(--accent-amber)}.lesson-electricity .capacitor-scene{border:1px solid var(--border-subtle);border-radius:var(--radius-lg);background:var(--bg-secondary);grid-template-columns:86px minmax(140px,1fr) 86px;align-items:stretch;width:min(100%,620px);min-height:220px;margin:1.5rem auto;padding:1.2rem;display:grid}.lesson-electricity .cap-plate{border-radius:var(--radius-sm);font:800 1.15rem var(--font-mono);writing-mode:vertical-rl;letter-spacing:.5em;place-items:center;padding:.6rem;display:grid}.lesson-electricity .cap-plate.negative{color:#082f49;background:var(--accent-cyan)}.lesson-electricity .cap-plate.positive{color:#4c0519;background:var(--accent-rose)}.lesson-electricity .cap-field{color:var(--text-primary);place-items:center;font-weight:700;display:grid;position:relative;overflow:hidden}.lesson-electricity .cap-field i{border-top:2px dashed var(--text-secondary);animation:1.6s ease-in-out infinite field-slide;position:absolute;left:10%;right:10%}.lesson-electricity .cap-field i:first-of-type{top:28%}.lesson-electricity .cap-field i:nth-of-type(2){animation-delay:-.5s;top:50%}.lesson-electricity .cap-field i:nth-of-type(3){animation-delay:-1s;top:72%}@keyframes field-slide{50%{opacity:.3;transform:translate(7px)}}.lesson-electricity .wave-compare svg{width:100%;height:auto;margin:.5rem 0;display:block}.lesson-electricity .wave-compare svg path{fill:none;stroke:var(--text-muted);stroke-width:1.5px}.lesson-electricity .wave-compare svg .signal{stroke:var(--accent-cyan);stroke-width:4px;stroke-linecap:round;stroke-dasharray:8 4;animation:1.3s linear infinite wave-march}@keyframes wave-march{to{stroke-dashoffset:-24px}}.lesson-electricity .conversion-line{border:1px solid var(--border-subtle);border-radius:var(--radius-md);background:var(--bg-secondary);flex-wrap:wrap;justify-content:center;align-items:center;gap:1rem;margin:1.4rem 0;padding:1rem;display:flex}.lesson-electricity .conversion-line i{color:var(--accent-amber);font-style:normal;font-weight:800}.lesson-electricity .subtitle-drawer summary{list-style:none}.lesson-electricity .subtitle-drawer summary::-webkit-details-marker{display:none}.lesson-electricity .subtitle-drawer[open] .subtitle-drawer-icon{transform:rotate(180deg)}.lesson-electricity .subtitle-drawer-content{display:block}.lesson-electricity .subtitle-columns{grid-template-columns:1fr 1fr;gap:1rem;display:grid}.lesson-electricity .subtitle-column{min-width:0}.lesson-electricity .subtitle-column h4{color:var(--text-primary);margin-bottom:.55rem}.lesson-electricity .subtitle-column pre,.lesson-electricity .subtitle-column p{white-space:pre-wrap;overflow-wrap:anywhere;font:inherit;color:var(--text-secondary);margin:0;line-height:1.75}.lesson-electricity .subtitle-column pre{color:var(--accent-cyan);font-style:italic}.lesson-electricity button:focus-visible,.lesson-electricity input:focus-visible,.lesson-electricity summary:focus-visible{outline:2px solid var(--accent-cyan);outline-offset:3px}@media (prefers-reduced-motion:reduce){.lesson-electricity .atom-nucleus,.lesson-electricity .atom-orbit i,.lesson-electricity .cap-field i,.lesson-electricity .wave-compare svg .signal{animation:none}}@media (width<=760px){.lesson-electricity .effect-grid,.lesson-electricity .resistance-factors{grid-template-columns:1fr 1fr}.lesson-electricity .compare-grid,.lesson-electricity .wave-compare,.lesson-electricity .subtitle-columns{grid-template-columns:1fr}.lesson-electricity .circuit-story,.lesson-electricity .transformer-flow{grid-template-columns:1fr;display:grid}.lesson-electricity .circuit-story i,.lesson-electricity .transformer-flow i{justify-self:center;transform:rotate(90deg)}.lesson-electricity .micro-canvas{aspect-ratio:1.35}}@media (width<=480px){.lesson-electricity .effect-grid,.lesson-electricity .resistance-factors,.lesson-electricity .direction-pair{grid-template-columns:1fr}.lesson-electricity .lesson22-lab{padding:.9rem}.lesson-electricity .atom-orbit{width:245px;height:105px}.lesson-electricity .atom-orbit i{animation-name:orbit-electron-mobile}.lesson-electricity .capacitor-scene{grid-template-columns:58px minmax(100px,1fr) 58px;padding:.75rem}}@keyframes orbit-electron-mobile{to{transform:rotate(360deg)translate(116px)rotate(-360deg)}}:root{--bg-primary:#0a0e17;--bg-secondary:#111827;--bg-card:#162032;--bg-card-hover:#1e2c45;--bg-input:#0d1524;--border-subtle:#22324e;--border-active:#3b82f6;--text-primary:#f8fafc;--text-secondary:#94a3b8;--text-muted:#64748b;--text-code:#38bdf8;--accent-cyan:#38bdf8;--accent-blue:#3b82f6;--accent-amber:#f59e0b;--accent-amber-glow:#f59e0b59;--accent-emerald:#10b981;--accent-emerald-glow:#10b98159;--accent-rose:#f43f5e;--accent-rose-glow:#f43f5e59;--accent-purple:#a855f7;--font-sans:-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;--font-mono:ui-monospace, "SF Mono", Menlo, Consolas, monospace;--shadow-sm:0 2px 8px #0000004d;--shadow-md:0 4px 20px #0006;--shadow-lg:0 10px 30px -5px #00000080;--shadow-glow-cyan:0 0 25px #38bdf840;--shadow-glow-amber:0 0 25px #f59e0b40;--radius-sm:6px;--radius-md:10px;--radius-lg:16px;--radius-full:9999px;--transition-fast:.15s ease;--transition-normal:.25s ease;--transition-slow:.4s cubic-bezier(.16, 1, .3, 1)}[data-theme=light]{--bg-primary:#f8fafc;--bg-secondary:#f1f5f9;--bg-card:#fff;--bg-card-hover:#f8fafc;--bg-input:#e2e8f0;--border-subtle:#cbd5e1;--border-active:#2563eb;--text-primary:#0f172a;--text-secondary:#475569;--text-muted:#64748b;--text-code:#0284c7;--shadow-sm:0 2px 8px #0000000d;--shadow-md:0 4px 16px #00000014;--shadow-lg:0 10px 25px #0000001f;--shadow-glow-cyan:0 0 20px #0284c726;--shadow-glow-amber:0 0 20px #d9770626}*{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth;font-size:16px}body{font-family:var(--font-sans);background-color:var(--bg-primary);color:var(--text-primary);transition:background-color var(--transition-normal), color var(--transition-normal);line-height:1.7;overflow-x:hidden}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--bg-primary)}::-webkit-scrollbar-thumb{background:var(--border-subtle);border-radius:var(--radius-full)}.top-navbar{z-index:1000;-webkit-backdrop-filter:blur(16px);border-bottom:1px solid var(--border-subtle);background:#0a0e17d9;justify-content:space-between;align-items:center;height:64px;padding:0 2rem;display:flex;position:sticky;top:0}[data-theme=light] .top-navbar{background:#ffffffe0}.brand-wrapper{color:inherit;align-items:center;gap:.75rem;text-decoration:none;display:flex}.brand-icon{border-radius:var(--radius-md);color:#fff;background:linear-gradient(135deg,#0ea5e9,#6366f1);justify-content:center;align-items:center;width:36px;height:36px;font-size:1.1rem;font-weight:800;display:flex;box-shadow:0 0 15px #0ea5e980}.brand-title{letter-spacing:-.01em;align-items:center;gap:.5rem;font-size:1.125rem;font-weight:700;display:flex}.brand-subtitle{border-radius:var(--radius-full);color:var(--accent-cyan);background:#38bdf826;border:1px solid #38bdf84d;padding:2px 8px;font-size:.75rem;font-weight:600}.nav-actions{align-items:center;gap:.75rem;display:flex}.nav-pill-btn{background:var(--bg-card);border:1px solid var(--border-subtle);color:var(--text-secondary);border-radius:var(--radius-full);cursor:pointer;transition:all var(--transition-fast);align-items:center;gap:.4rem;padding:.4rem .9rem;font-size:.85rem;font-weight:500;display:inline-flex}.nav-pill-btn:hover{background:var(--bg-card-hover);color:var(--text-primary);border-color:var(--accent-cyan)}.reading-progress-track{background:#ffffff0d;width:100%;height:3px;position:absolute;bottom:0;left:0}.reading-progress-bar{background:linear-gradient(90deg, var(--accent-cyan), var(--accent-amber));width:0%;height:100%;transition:width .1s linear}.app-layout{max-width:1440px;min-height:calc(100vh - 64px);margin:0 auto;display:flex;position:relative}.sidebar{border-right:1px solid var(--border-subtle);background:var(--bg-primary);flex-shrink:0;width:320px;height:calc(100vh - 64px);padding:1.75rem 1.25rem;position:sticky;top:64px;overflow-y:auto}.sidebar-section-title{text-transform:uppercase;letter-spacing:.08em;color:var(--text-muted);margin-bottom:.75rem;padding-left:.5rem;font-size:.75rem;font-weight:700}.series-badge-card{border:1px solid var(--border-subtle);border-radius:var(--radius-lg);background:linear-gradient(145deg,#1e293b99,#0f172ae6);margin-bottom:1.5rem;padding:1rem;position:relative;overflow:hidden}.series-badge-card:before{content:"";background:var(--accent-cyan);width:4px;height:100%;position:absolute;top:0;left:0}.series-badge-title{color:var(--text-primary);font-size:.85rem;font-weight:700}.series-badge-desc{color:var(--text-secondary);margin-top:.3rem;font-size:.75rem;line-height:1.4}.toc-nav{flex-direction:column;gap:.35rem;display:flex}.toc-link{border-radius:var(--radius-md);color:var(--text-secondary);transition:all var(--transition-fast);border-left:2px solid #0000;align-items:center;gap:.65rem;padding:.6rem .75rem;font-size:.85rem;text-decoration:none;display:flex}.toc-link:hover{background:var(--bg-card);color:var(--text-primary)}.toc-link.active{color:var(--accent-cyan);border-left-color:var(--accent-cyan);background:#38bdf81f;font-weight:600}.toc-num{font-family:var(--font-mono);color:var(--text-muted);flex-shrink:0;width:20px;font-size:.75rem}.sidebar-stats{border-top:1px solid var(--border-subtle);grid-template-columns:1fr 1fr;gap:.6rem;margin-top:1.5rem;padding-top:1.25rem;display:grid}.stat-box{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-sm);text-align:center;padding:.6rem}.stat-val{color:var(--accent-cyan);font-size:1.1rem;font-weight:700;font-family:var(--font-mono)}.stat-lbl{color:var(--text-muted);font-size:.7rem}.main-content{flex:1;min-width:0;padding:2.5rem 3.5rem 6rem}.lesson-hero{border-bottom:1px solid var(--border-subtle);margin-bottom:3rem;padding-bottom:2rem}.lesson-meta-bar{flex-wrap:wrap;align-items:center;gap:.75rem;margin-bottom:1rem;display:flex}.badge{border-radius:var(--radius-full);align-items:center;gap:.35rem;padding:.25rem .65rem;font-size:.75rem;font-weight:600;display:inline-flex}.badge-cyan{color:var(--accent-cyan);background:#38bdf826;border:1px solid #38bdf840}.badge-amber{color:var(--accent-amber);background:#f59e0b26;border:1px solid #f59e0b40}.badge-emerald{color:var(--accent-emerald);background:#10b98126;border:1px solid #10b98140}.lesson-title{letter-spacing:-.02em;background:linear-gradient(135deg,#fff 30%,#94a3b8 100%);-webkit-text-fill-color:transparent;-webkit-background-clip:text;margin-bottom:.75rem;font-size:2.4rem;font-weight:800;line-height:1.25}[data-theme=light] .lesson-title{background:linear-gradient(135deg,#0f172a 30%,#334155 100%);-webkit-text-fill-color:transparent;-webkit-background-clip:text}.lesson-subtitle{color:var(--text-secondary);max-width:800px;font-size:1.15rem;line-height:1.6}.series-overview-pills{flex-wrap:wrap;gap:.75rem;margin-top:1.25rem;display:flex}.series-pill{border-radius:var(--radius-md);background:var(--bg-card);border:1px solid var(--border-subtle);color:var(--text-secondary);align-items:center;gap:.4rem;padding:.4rem .85rem;font-size:.85rem;display:flex}.series-pill.active{border-color:var(--accent-cyan);color:var(--accent-cyan);background:#38bdf81f;font-weight:600}.lesson-section{margin-bottom:4.5rem;scroll-margin-top:90px}.section-header{border-bottom:1px solid var(--border-subtle);align-items:baseline;gap:.75rem;margin-bottom:1.25rem;padding-bottom:.6rem;display:flex}.section-index{font-family:var(--font-mono);color:var(--accent-cyan);font-size:1rem;font-weight:700}.section-heading{color:var(--text-primary);letter-spacing:-.01em;font-size:1.55rem;font-weight:700}.section-narrative{color:var(--text-secondary);margin-bottom:1.5rem;font-size:1.05rem;line-height:1.8}.section-narrative p{margin-bottom:1.1rem}.strong-term{color:var(--text-primary);border-bottom:1px dashed var(--accent-cyan);font-weight:600}.deep-dive-card{border-radius:var(--radius-lg);background:linear-gradient(135deg,#a855f714,#3b82f60d);border:1px solid #a855f74d;margin:1.75rem 0;padding:1.25rem 1.5rem;position:relative}.deep-dive-header{color:#c084fc;align-items:center;gap:.5rem;margin-bottom:.6rem;font-size:.95rem;font-weight:700;display:flex}.deep-dive-body{color:var(--text-secondary);font-size:.925rem;line-height:1.65}.subtitle-drawer{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);transition:all var(--transition-fast);margin:1.5rem 0;overflow:hidden}.subtitle-drawer-header{cursor:pointer;-webkit-user-select:none;user-select:none;background:#ffffff05;justify-content:space-between;align-items:center;padding:.75rem 1.25rem;display:flex}.subtitle-drawer-header:hover{background:#ffffff0d}.subtitle-drawer-title{color:var(--text-secondary);align-items:center;gap:.5rem;font-size:.85rem;font-weight:600;display:flex}.subtitle-drawer-icon{transition:transform var(--transition-fast);font-size:.8rem}.subtitle-drawer.open .subtitle-drawer-icon{transform:rotate(180deg)}.subtitle-drawer-content{border-top:1px solid var(--border-subtle);background:var(--bg-input);padding:1rem 1.25rem;display:none}.subtitle-drawer.open .subtitle-drawer-content{display:block}.subtitle-line{border-bottom:1px dashed #ffffff0f;margin-bottom:.75rem;padding-bottom:.75rem}.subtitle-line:last-child{border-bottom:none;margin-bottom:0;padding-bottom:0}.subtitle-en{font-family:var(--font-sans);color:#38bdf8;margin-bottom:.2rem;font-size:.9rem;font-style:italic}.subtitle-cn{color:var(--text-secondary);font-size:.85rem}.visual-lab-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);box-shadow:var(--shadow-md);transition:border-color var(--transition-normal);margin:2rem 0;padding:1.5rem;position:relative}.visual-lab-card:hover{border-color:#38bdf866}.lab-header{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:.75rem;margin-bottom:1rem;display:flex}.lab-badge{text-transform:uppercase;letter-spacing:.05em;color:var(--accent-cyan);align-items:center;gap:.4rem;font-size:.8rem;font-weight:700;display:inline-flex}.lab-title{color:var(--text-primary);font-size:1.15rem;font-weight:700}.lab-canvas-container{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);width:100%;margin-bottom:1rem;position:relative;overflow:hidden}canvas.lab-canvas{width:100%;height:280px;display:block}.lab-controls-bar{border:1px solid var(--border-subtle);border-radius:var(--radius-md);background:#00000040;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:1rem;padding:.75rem 1rem;display:flex}.control-group{align-items:center;gap:.75rem;display:flex}.control-label{color:var(--text-secondary);font-size:.85rem;font-weight:500}.control-value{font-family:var(--font-mono);color:var(--accent-cyan);min-width:60px;font-size:.95rem;font-weight:700}.btn-primary{color:#fff;border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);background:linear-gradient(135deg,#0284c7,#2563eb);border:none;align-items:center;gap:.4rem;padding:.45rem 1.1rem;font-size:.85rem;font-weight:600;display:inline-flex;box-shadow:0 2px 10px #0284c74d}.btn-primary:hover{filter:brightness(1.15);transform:translateY(-1px)}.btn-primary:active{transform:translateY(0)}.btn-secondary{background:var(--bg-card);color:var(--text-primary);border:1px solid var(--border-subtle);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);align-items:center;gap:.4rem;padding:.45rem 1rem;font-size:.85rem;font-weight:500;display:inline-flex}.btn-danger{color:var(--accent-rose);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);background:#f43f5e26;border:1px solid #f43f5e4d;padding:.45rem 1rem;font-size:.85rem;font-weight:600}.btn-danger:hover{border-color:var(--accent-rose);background:#f43f5e40}input[type=range].lab-slider{-webkit-appearance:none;background:var(--border-subtle);width:160px;height:6px;transition:background var(--transition-fast);border-radius:3px;outline:none}input[type=range].lab-slider::-webkit-slider-thumb{appearance:none;background:var(--accent-cyan);cursor:pointer;border-radius:50%;width:18px;height:18px;transition:transform .1s;box-shadow:0 0 10px #38bdf899}input[type=range].lab-slider::-webkit-slider-thumb:hover{transform:scale(1.2)}.segmented-control{background:var(--bg-input);border-radius:var(--radius-md);border:1px solid var(--border-subtle);padding:3px;display:inline-flex}.seg-btn{color:var(--text-secondary);border-radius:calc(var(--radius-md) - 3px);cursor:pointer;transition:all var(--transition-fast);background:0 0;border:none;padding:.35rem .85rem;font-size:.8rem;font-weight:600}.seg-btn.active{background:var(--accent-blue);color:#fff;box-shadow:0 2px 6px #00000040}.lab-caption{color:var(--text-muted);align-items:center;gap:.5rem;margin-top:.75rem;font-size:.825rem;display:flex}.scale-grid{grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:1rem;margin:1.5rem 0;display:grid}.scale-card{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);padding:1rem;position:relative;overflow:hidden}.scale-card.danger:hover,.scale-card.danger.selected{border-color:var(--accent-rose)}.scale-val{font-family:var(--font-mono);color:var(--accent-cyan);font-size:1.25rem;font-weight:700}.scale-card.danger .scale-val{color:var(--accent-rose)}.scale-name{color:var(--text-primary);margin-top:.25rem;font-size:.9rem;font-weight:600}.scale-desc{color:var(--text-muted);margin-top:.35rem;font-size:.78rem;line-height:1.4}.scale-type-badge{letter-spacing:.04em;text-transform:none;border:1px solid #0000;border-radius:999px;margin-bottom:.55rem;padding:3px 10px;font-size:.7rem;font-weight:600;display:inline-block}.scale-type-badge[data-kind=device]{color:var(--accent-cyan);background:#38bdf81f;border-color:#38bdf84d}.scale-type-badge[data-kind=natural]{color:var(--accent-amber);background:#f59e0b1f;border-color:#f59e0b4d}.scale-type-badge[data-kind=body]{color:var(--accent-rose);background:#f43f5e2e;border-color:#f43f5e66;font-weight:700;animation:2.5s ease-in-out infinite scale-body-badge-pulse}@keyframes scale-body-badge-pulse{0%,to{box-shadow:0 0 #f43f5e00}50%{box-shadow:0 0 0 4px #f43f5e1f}}@media (prefers-reduced-motion:reduce){.scale-type-badge[data-kind=body]{animation:none}}.scale-card.scale-kind-body{border-color:#f43f5e59}.scale-card.scale-kind-body:hover,.scale-card.scale-kind-body.selected{border-color:var(--accent-rose);box-shadow:0 0 0 1px #f43f5e73}.scale-intro-callout{border:1px solid var(--border-subtle);border-radius:var(--radius-md);color:var(--text-secondary);background:linear-gradient(135deg,#38bdf814,#f43f5e14);align-items:flex-start;gap:.75rem;margin:1rem 0 1.5rem;padding:1rem 1.25rem;font-size:.9rem;line-height:1.7;display:flex}.scale-intro-icon{flex-shrink:0;font-size:1.2rem}.scale-tag-cyan,.scale-tag-rose{white-space:nowrap;border-radius:6px;margin:0 2px;padding:1px 9px;font-size:.82em;font-weight:600;display:inline-block}.scale-tag-cyan{color:var(--accent-cyan);background:#38bdf826}.scale-tag-rose{color:var(--accent-rose);background:#f43f5e2e}.scale-group-heading{color:var(--text-primary);letter-spacing:.01em;align-items:center;gap:.7rem;margin:2rem 0 1rem;font-size:1.05rem;font-weight:700;display:flex}.scale-group-bar{border-radius:2px;flex-shrink:0;width:4px;height:22px}.scale-group-bar.circuit{background:linear-gradient(180deg, var(--accent-cyan), var(--accent-cyan) 60%, transparent)}.scale-group-bar.body{background:linear-gradient(180deg, var(--accent-rose), var(--accent-rose) 60%, transparent)}.scale-mythbusting-callout{border-radius:var(--radius-lg);background:linear-gradient(135deg,#a855f70f,#f43f5e14);border:1px solid #f43f5e4d;margin:2rem 0 1.75rem;padding:1.25rem 1.5rem;position:relative}.mythbusting-header{color:var(--accent-rose);align-items:center;gap:.5rem;margin-bottom:.85rem;font-size:1.05rem;display:flex}.mythbusting-body{color:var(--text-secondary);font-size:.92rem;line-height:1.7}.mythbusting-body p{margin:.5rem 0}.mythbusting-body code{background:var(--bg-card);border:1px solid var(--border-subtle);font-family:var(--font-mono);color:var(--accent-amber);border-radius:4px;padding:1px 7px;font-size:.92em}.mythbusting-calc{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);font-family:var(--font-mono);flex-direction:column;margin:.85rem 0;padding:.65rem 1rem;font-size:.88rem;display:flex}.mythbusting-row{border-bottom:1px dashed var(--border-subtle);justify-content:space-between;align-items:center;gap:1rem;padding:.4rem 0;display:flex}.mythbusting-row:last-child{border-bottom:none}.mythbusting-row.safe{color:var(--accent-emerald)}.mythbusting-row.warn{color:var(--accent-amber)}.mythbusting-row.danger{color:var(--accent-rose)}.quiz-section{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);margin:4rem 0 2rem;padding:2rem}.quiz-header{margin-bottom:1.5rem}.quiz-title{color:var(--text-primary);align-items:center;gap:.5rem;font-size:1.4rem;font-weight:700;display:flex}.quiz-subtitle{color:var(--text-secondary);margin-top:.35rem;font-size:.9rem}.quiz-item{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);margin-bottom:1.25rem;padding:1.25rem}.quiz-question{color:var(--text-primary);margin-bottom:.85rem;font-size:.98rem;font-weight:600}.quiz-options{flex-direction:column;gap:.5rem;display:flex}.quiz-option-btn{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-sm);text-align:left;color:var(--text-secondary);cursor:pointer;transition:all var(--transition-fast);justify-content:space-between;align-items:center;padding:.65rem 1rem;font-size:.875rem;display:flex}.quiz-option-btn:hover{background:var(--bg-card-hover);color:var(--text-primary);border-color:var(--accent-blue)}.quiz-option-btn.correct{font-weight:600;border-color:var(--accent-emerald)!important;color:var(--accent-emerald)!important;background:#10b98126!important}.quiz-option-btn.wrong{border-color:var(--accent-rose)!important;color:var(--accent-rose)!important;background:#f43f5e26!important}.quiz-explanation{border-radius:var(--radius-sm);border-left:3px solid var(--accent-cyan);color:var(--text-secondary);background:#38bdf814;margin-top:.75rem;padding:.75rem;font-size:.825rem;display:none}.math-formula-card{border-radius:var(--radius-md);text-align:center;background:linear-gradient(145deg,#0d1524f2,#0f172afa);border:1px solid #38bdf859;margin:1.5rem 0;padding:1.25rem 1.5rem;box-shadow:inset 0 2px 6px #0006,0 4px 15px #0003}.math-formula-tag{color:var(--accent-cyan);text-transform:uppercase;letter-spacing:.08em;border-radius:var(--radius-full);background:#38bdf81a;border:1px solid #38bdf833;margin-bottom:.75rem;padding:.2rem .6rem;font-size:.75rem;font-weight:700;display:inline-block}.math-formula-body{font-family:var(--font-mono);color:#f8fafc;flex-wrap:wrap;justify-content:center;align-items:center;gap:.75rem;font-size:1.2rem;font-weight:700;display:flex}.math-highlight{color:var(--accent-cyan);border-radius:var(--radius-sm);background:#38bdf81f;border:1px solid #38bdf84d;padding:.2rem .65rem}.math-operator{color:var(--accent-amber);font-size:1.25rem}.math-val{color:#fbbf24;letter-spacing:.02em;font-size:1.3rem}.math-subtext{color:var(--text-secondary);border-top:1px dashed #ffffff14;margin-top:.75rem;padding-top:.6rem;font-size:.825rem;line-height:1.5}.site-footer{border-top:1px solid var(--border-subtle);color:var(--text-muted);justify-content:space-between;align-items:center;margin-top:4rem;padding-top:2rem;font-size:.85rem;display:flex}.footer-next-btn{background:linear-gradient(135deg, var(--accent-blue), #6366f1);color:#fff;border-radius:var(--radius-md);transition:transform var(--transition-fast);align-items:center;gap:.4rem;padding:.55rem 1.25rem;font-weight:600;text-decoration:none;display:inline-flex}.footer-next-btn:hover{transform:translateY(-2px)}@media (width<=1024px){.app-layout{flex-direction:column}.sidebar{border-right:none;border-bottom:1px solid var(--border-subtle);width:100%;height:auto;padding:1rem 1.5rem;position:static}.toc-nav{grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:.4rem;display:grid}.main-content{padding:1.5rem}}.css-diagram-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);transition:all var(--transition-normal);margin:1.5rem 0 2rem;padding:1.5rem}.css-diagram-card:hover{border-color:#38bdf866}.diagram-header{border-bottom:1px solid #ffffff0d;justify-content:space-between;align-items:center;margin-bottom:1.25rem;padding-bottom:.75rem;display:flex}.diagram-badge{text-transform:uppercase;letter-spacing:.05em;color:var(--accent-cyan);border-radius:var(--radius-full);background:#38bdf81a;border:1px solid #38bdf833;align-items:center;gap:.35rem;padding:.2rem .6rem;font-size:.75rem;font-weight:700;display:inline-flex}.diagram-title{color:var(--text-primary);font-size:1.05rem;font-weight:700}.atom-diagram-layout{grid-template-columns:280px 1fr;align-items:center;gap:2rem;display:grid}@media (width<=768px){.atom-diagram-layout{grid-template-columns:1fr}}.atom-stage{perspective:800px;justify-content:center;align-items:center;width:240px;height:240px;margin:0 auto;display:flex;position:relative}.css-nucleus{z-index:10;background:radial-gradient(circle at 35% 35%,#ff4d6d,#e11d48 60%,#881337 100%);border-radius:50%;flex-direction:column;justify-content:center;align-items:center;width:50px;height:50px;animation:2.4s ease-in-out infinite alternate nucleus-heartbeat;display:flex;position:relative;box-shadow:0 0 25px #f43f5eb3,inset 0 2px 4px #fff9}.nucleus-symbol{font-family:var(--font-mono);color:#fff;text-shadow:0 1px 3px #00000080;font-size:1.25rem;font-weight:800;line-height:1}.nucleus-tag{color:#ffe4e6;letter-spacing:-.02em;font-size:.6rem;font-weight:700}@keyframes nucleus-heartbeat{0%{transform:scale(.96);box-shadow:0 0 15px #f43f5e80}to{transform:scale(1.06);box-shadow:0 0 30px #f43f5ee6}}.orbit-ring{width:210px;height:210px;transform-style:preserve-3d;pointer-events:none;border:1.5px dashed #38bdf859;border-radius:50%;margin-top:-105px;margin-left:-105px;position:absolute;top:50%;left:50%}.orbit-ring-1{transform:rotate(0)rotateX(68deg)}.orbit-ring-2{transform:rotate(60deg)rotateX(68deg)}.orbit-ring-3{transform:rotate(120deg)rotateX(68deg)}.css-electron-holder{width:100%;height:100%;animation:3.5s linear infinite rotate-electron;position:absolute;top:0;left:0}.orbit-ring-2 .css-electron-holder{animation-duration:4.8s;animation-direction:reverse}.orbit-ring-3 .css-electron-holder{animation-duration:4s}.css-electron-bead{width:15px;height:15px;font-family:var(--font-mono);color:#0f172a;background:radial-gradient(circle at 35% 35%,#7dd3fc,#0ea5e9 60%,#0369a1 100%);border-radius:50%;justify-content:center;align-items:center;font-size:11px;font-weight:800;display:flex;position:absolute;top:-7px;left:calc(50% - 7px);box-shadow:0 0 14px #38bdf8f2,inset 0 1px 3px #fffc}@keyframes rotate-electron{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.atom-notes-list{flex-direction:column;gap:1rem;display:flex}.atom-note-item{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);transition:transform var(--transition-fast);gap:.85rem;padding:.85rem 1.1rem;display:flex}.atom-note-item:hover{border-color:#38bdf866;transform:translate(4px)}.note-icon-badge{border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:32px;height:32px;font-size:.9rem;font-weight:800;display:flex}.badge-red{color:#f43f5e;background:#f43f5e26;border:1px solid #f43f5e4d}.badge-blue{color:#38bdf8;background:#38bdf826;border:1px solid #38bdf84d}.note-title{color:var(--text-primary);margin-bottom:.2rem;font-size:.9rem;font-weight:700}.note-desc{color:var(--text-secondary);font-size:.825rem;line-height:1.5}.charge-interaction-grid{grid-template-columns:1fr 1fr;gap:1.25rem;margin:1.5rem 0;display:grid}@media (width<=640px){.charge-interaction-grid{grid-template-columns:1fr}}.charge-card{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);text-align:center;padding:1.25rem;position:relative;overflow:hidden}.charge-card-title{justify-content:center;align-items:center;gap:.4rem;margin-bottom:.5rem;font-size:.95rem;font-weight:700;display:flex}.charge-card.attract .charge-card-title{color:#10b981}.charge-card.repel .charge-card-title{color:#f59e0b}.charge-particles-row{justify-content:center;align-items:center;gap:1.5rem;margin:1.5rem 0;display:flex;position:relative}.charge-ball{width:48px;height:48px;font-family:var(--font-mono);z-index:2;border-radius:50%;justify-content:center;align-items:center;font-size:1.5rem;font-weight:800;display:flex;position:relative;box-shadow:0 4px 15px #0006}.charge-ball.pos{color:#fff;background:radial-gradient(circle at 35% 35%,#ff4d6d,#e11d48);box-shadow:0 0 20px #f43f5e99}.charge-ball.neg{color:#0f172a;background:radial-gradient(circle at 35% 35%,#7dd3fc,#0284c7);box-shadow:0 0 20px #38bdf899}.force-field-visual{color:var(--text-muted);flex-direction:column;align-items:center;gap:.3rem;font-size:1.25rem;display:flex}.force-label{text-transform:uppercase;letter-spacing:.06em;font-size:.725rem;font-weight:700}.charge-card.attract .charge-ball.pos{animation:2s ease-in-out infinite alternate attract-left}.charge-card.attract .charge-ball.neg{animation:2s ease-in-out infinite alternate attract-right}@keyframes attract-left{0%{transform:translate(0)}to{transform:translate(8px)}}@keyframes attract-right{0%{transform:translate(0)}to{transform:translate(-8px)}}.charge-card.repel .charge-ball:first-child{animation:2s ease-in-out infinite alternate repel-left}.charge-card.repel .charge-ball:last-child{animation:2s ease-in-out infinite alternate repel-right}@keyframes repel-left{0%{transform:translate(0)}to{transform:translate(-8px)}}@keyframes repel-right{0%{transform:translate(0)}to{transform:translate(8px)}}.charge-card-desc{color:var(--text-secondary);text-align:left;font-size:.825rem;line-height:1.5}.material-compare-grid{grid-template-columns:1fr 1fr;gap:1.25rem;margin:1.5rem 0;display:grid}@media (width<=700px){.material-compare-grid{grid-template-columns:1fr}}.material-card{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);padding:1.25rem}.material-card-header{justify-content:space-between;align-items:center;margin-bottom:1rem;display:flex}.material-card-title{color:var(--text-primary);align-items:center;gap:.4rem;font-size:.95rem;font-weight:700;display:flex}.material-badge-tag{border-radius:var(--radius-full);padding:.15rem .5rem;font-size:.7rem;font-weight:600}.tag-gray{color:#94a3b8;background:#94a3b826;border:1px solid #94a3b84d}.tag-copper{color:#f59e0b;background:#f59e0b26;border:1px solid #f59e0b4d}.micro-lattice-preview{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);background:#0000004d;justify-content:space-around;align-items:center;height:120px;margin-bottom:.85rem;padding:0 1rem;display:flex;position:relative;overflow:hidden}.insulator-atom{border:1.5px solid #94a3b866;border-radius:50%;justify-content:center;align-items:center;width:50px;height:50px;display:flex;position:relative}.insulator-atom-core{color:#fff;background:#64748b;border-radius:50%;justify-content:center;align-items:center;width:22px;height:22px;font-size:9px;font-weight:700;display:flex}.insulator-locked-bead{background:#38bdf8;border-radius:50%;width:10px;height:10px;position:absolute;top:-5px;right:5px}.lock-icon-badge{font-size:10px;position:absolute;bottom:-6px}.conductor-atom-core{color:#fff;background:#e11d48;border-radius:50%;justify-content:center;align-items:center;width:24px;height:24px;font-size:9px;font-weight:700;display:flex;box-shadow:0 0 8px #e11d4880}.floating-electron{color:#0f172a;background:#38bdf8;border-radius:50%;justify-content:center;align-items:center;width:11px;height:11px;font-size:8px;font-weight:800;display:flex;position:absolute;box-shadow:0 0 8px #38bdf8}.fe-1{animation:3s ease-in-out infinite alternate float-e1;top:25px;left:25%}.fe-2{animation:2.5s ease-in-out infinite alternate float-e2;bottom:22px;right:30%}.fe-3{animation:3.5s ease-in-out infinite alternate float-e3;top:30px;right:15%}@keyframes float-e1{0%{transform:translate(0)}to{transform:translate(45px,20px)}}@keyframes float-e2{0%{transform:translate(0)}to{transform:translate(-35px,-25px)}}@keyframes float-e3{0%{transform:translate(0)}to{transform:translate(-50px,15px)}}.material-card-desc{color:var(--text-secondary);font-size:.825rem;line-height:1.5}.conga-duo-container{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);margin:1.5rem 0 2rem;padding:1.5rem}.conga-lane{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);margin-bottom:1.25rem;padding:1.25rem 1.5rem;position:relative;overflow:hidden}.conga-lane-title{justify-content:space-between;align-items:center;margin-bottom:1rem;font-size:.875rem;font-weight:700;display:flex}.conga-lane-title .badge{font-size:.7rem}.human-conga-track{border-radius:var(--radius-sm);background:#00000040;justify-content:space-around;align-items:flex-end;height:95px;padding:0 1rem;display:flex;position:relative}.dancer-unit{flex-direction:column;align-items:center;animation:1.8s ease-in-out infinite alternate dancer-step;display:flex;position:relative}.dancer-unit:first-child{animation-delay:0s}.dancer-unit:nth-child(2){animation-delay:.18s}.dancer-unit:nth-child(3){animation-delay:.36s}.dancer-unit:nth-child(4){animation-delay:.54s}.dancer-unit:nth-child(5){animation-delay:.72s}.dancer-head{background:radial-gradient(circle at 35% 35%,#fbbf24,#d97706);border-radius:50%;width:22px;height:22px;position:relative;box-shadow:0 2px 6px #0000004d}.dancer-body{background:linear-gradient(#3b82f6,#1d4ed8);border-radius:6px;width:14px;height:28px;margin-top:2px;position:relative}.dancer-arm-forward{background:#fbbf24;border-radius:2px;width:20px;height:4px;position:absolute;top:6px;right:-16px;transform:rotate(-10deg);box-shadow:0 1px 3px #0000004d}.dancer-legs{gap:4px;display:flex}.dancer-leg{background:#475569;border-radius:2px;width:4px;height:18px}@keyframes dancer-step{0%{transform:translate(0)translateY(0)rotate(0)}50%{transform:translate(12px)translateY(-4px)rotate(3deg)}to{transform:translate(20px)translateY(0)rotate(0)}}.nanowire-track{border-radius:var(--radius-sm);background:#b4530914;border:1.5px solid #f59e0b4d;justify-content:space-around;align-items:center;height:95px;padding:0 1rem;display:flex;position:relative}.nanowire-atom-node{z-index:2;flex-direction:column;align-items:center;display:flex;position:relative}.nanowire-cu-core{color:#fff;width:36px;height:36px;font-family:var(--font-mono);background:radial-gradient(circle at 35% 35%,#ff4d6d,#be123c);border-radius:50%;justify-content:center;align-items:center;font-size:11px;font-weight:800;display:flex;box-shadow:0 0 12px #f43f5e80}.nanowire-electron{color:#0f172a;background:radial-gradient(circle at 35% 35%,#7dd3fc,#0284c7);border-radius:50%;justify-content:center;align-items:center;width:18px;height:18px;font-size:11px;font-weight:800;animation:1.8s ease-in-out infinite alternate electron-conga-jump;display:flex;position:absolute;top:9px;right:-12px;box-shadow:0 0 10px #38bdf8}.nanowire-atom-node:first-child .nanowire-electron{animation-delay:0s}.nanowire-atom-node:nth-child(2) .nanowire-electron{animation-delay:.18s}.nanowire-atom-node:nth-child(3) .nanowire-electron{animation-delay:.36s}.nanowire-atom-node:nth-child(4) .nanowire-electron{animation-delay:.54s}.nanowire-atom-node:nth-child(5) .nanowire-electron{animation-delay:.72s}@keyframes electron-conga-jump{0%{transform:translate(0)}40%{transform:translate(18px)scale(1.15)}to{transform:translate(26px)}}.conga-repel-wave{color:#f59e0b;font-size:1.2rem;animation:1.8s ease-in-out infinite alternate repel-sparkle}@keyframes repel-sparkle{0%{opacity:.2;transform:scale(.8)}50%{opacity:1;transform:scale(1.3)}to{opacity:.4;transform:scale(1)}}.conga-summary-grid{grid-template-columns:1fr 1fr;gap:1rem;margin-top:1rem;display:grid}@media (width<=640px){.conga-summary-grid{grid-template-columns:1fr}}.conga-summary-item{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-sm);color:var(--text-secondary);padding:.75rem 1rem;font-size:.8rem;line-height:1.5}.conga-summary-item strong{color:var(--text-primary);margin-bottom:.2rem;display:block}.switch-mechanic-grid{grid-template-columns:1fr 1fr;gap:1.25rem;margin:1.5rem 0;display:grid}@media (width<=640px){.switch-mechanic-grid{grid-template-columns:1fr}}.switch-box{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);padding:1.25rem}.switch-graphic{border-radius:var(--radius-sm);background:#00000040;justify-content:center;align-items:center;height:90px;margin-bottom:.75rem;display:flex;position:relative}.switch-terminal{background:#f59e0b;border-radius:50%;width:12px;height:12px}.switch-blade{transform-origin:0;background:#fbbf24;border-radius:3px;width:60px;height:5px;transition:transform .3s}.switch-box.closed .switch-blade{transform:rotate(0);box-shadow:0 0 10px #fbbf24cc}.switch-box.open .switch-blade{transform:rotate(-35deg)}.voltage-push-demo{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);justify-content:space-between;align-items:center;margin:2rem 0;padding:2rem;display:flex;position:relative}.vpd-supply{border-radius:var(--radius-md);text-align:center;z-index:2;background:linear-gradient(145deg,#1e293b,#0f172a);border:2px solid #334155;width:100px;padding:1rem;position:relative}.vpd-voltage-label{font-family:var(--font-mono);color:var(--accent-amber);text-shadow:0 0 10px var(--accent-amber-glow);font-size:1.25rem;font-weight:700}.vpd-wire{background:var(--border-subtle);z-index:1;flex:1;height:4px;position:relative}.vpd-wire:after{content:"";background-image:radial-gradient(circle, var(--accent-amber) 30%, transparent 30%);background-size:20px 10px;height:10px;animation:1s linear infinite wire-flow;position:absolute;top:-3px;left:0;right:0}.vpd-motor{background:var(--bg-input);border:4px solid var(--border-subtle);z-index:2;border-radius:50%;justify-content:center;align-items:center;width:80px;height:80px;display:flex;position:relative}.vpd-motor:before{content:"⚙️";font-size:2rem;animation:3s linear infinite spin}.vpd-current-arrow{color:var(--accent-amber);font-size:1.5rem;animation:1s infinite alternate bounce-right;position:absolute;top:-25px;left:50%;transform:translate(-50%)}.signal-power-compare{gap:1.5rem;margin:2rem 0;display:flex}@media (width<=768px){.signal-power-compare{flex-direction:column}}.sp-track{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);flex:1;padding:1.5rem;position:relative;overflow:hidden}.sp-track-power{border-bottom:4px solid var(--accent-amber)}.sp-track-signal{border-bottom:4px solid var(--accent-cyan)}.sp-track-title{color:var(--text-primary);margin-bottom:1rem;font-size:1.1rem;font-weight:700}.sp-track-icon{margin-bottom:1rem;font-size:2.5rem}.sp-track-detail{color:var(--text-secondary);font-size:.9rem}.sp-track-power .sp-track-icon{color:var(--accent-amber)}.sp-track-signal .sp-track-icon{color:var(--accent-cyan);white-space:nowrap;animation:4s linear infinite binary-wave;display:inline-block;overflow:hidden}.battery-section-diagram{flex-direction:column;align-items:center;margin:2rem 0;display:flex}.battery-body{border:4px solid var(--border-subtle);border-radius:15px;width:300px;height:120px;display:flex;position:relative;overflow:hidden}.battery-negative{color:#fff;background:#1e3a8a;flex:1;justify-content:center;align-items:center;font-size:2rem;font-weight:700;display:flex;position:relative}.battery-positive{color:#fff;background:#991b1b;flex:1;justify-content:center;align-items:center;font-size:2rem;font-weight:700;display:flex}.battery-chemistry{background:linear-gradient(90deg,#1e3a8a80,#991b1b80);animation:2s ease-in-out infinite alternate battery-shimmer;position:absolute;inset:0 30%}.battery-labels{width:300px;color:var(--text-secondary);justify-content:space-between;margin-top:1rem;font-size:.85rem;display:flex}.battery-electron-flow{color:var(--accent-amber);letter-spacing:.5rem;margin-top:1rem;font-size:1.2rem}.potential-energy-trio{grid-template-columns:repeat(3,1fr);gap:1.5rem;margin:2rem 0;display:grid}@media (width<=768px){.potential-energy-trio{grid-template-columns:1fr}}.pe-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);text-align:center;cursor:pointer;transition:all var(--transition-fast);padding:1.5rem}.pe-card:hover{border-color:var(--accent-cyan);transform:translateY(-5px)}.pe-status{color:var(--accent-amber);text-transform:uppercase;margin-top:1rem;font-size:.8rem;font-weight:700}.pe-card:hover .pe-status{color:var(--accent-emerald)}.pe-card:hover .pe-status:after{content:" (Released!)"}.pe-card-elastic:hover .pe-icon{animation:.5s ease-out elastic-snap}.pe-card-gravity:hover .pe-icon{animation:.5s ease-in forwards ball-drop}.pe-card-battery:hover .pe-icon{color:var(--accent-amber);text-shadow:0 0 10px var(--accent-amber-glow)}.pe-icon{margin-bottom:1rem;font-size:3rem;display:inline-block}.voltmeter-diagram{background:var(--bg-input);border-radius:var(--radius-lg);justify-content:center;align-items:center;gap:2rem;margin:2rem 0;padding:2rem;display:flex}.vm-battery-9v{background:#334155;border:2px solid #475569;border-radius:4px;width:60px;height:100px;position:relative}.vm-battery-9v:before,.vm-battery-9v:after{content:"";background:#cbd5e1;border-radius:2px 2px 0 0;height:10px;position:absolute;top:-10px}.vm-battery-9v:before{width:12px;left:10px}.vm-battery-9v:after{width:12px;right:10px}.vm-usb-port{background:#1e293b;border:2px solid #cbd5e1;border-radius:2px;justify-content:space-around;align-items:center;width:80px;height:30px;display:flex}.vm-probe{flex-direction:column;align-items:center;gap:.5rem;display:flex}.vm-reading{color:#10b981;font-family:var(--font-mono);background:#000;border:2px solid #333;border-radius:4px;padding:.5rem 1rem;font-size:1.5rem;animation:2s infinite alternate probe-pulse;box-shadow:inset 0 0 10px #10b98133}.joule-scale-container{flex-wrap:wrap;gap:1.5rem;margin:2rem 0;display:flex}.joule-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);text-align:center;cursor:pointer;min-width:200px;transition:all var(--transition-fast);flex:1;padding:1.5rem}.joule-card:hover,.joule-card.selected{border-color:var(--accent-amber);box-shadow:var(--shadow-glow-amber)}.joule-icon{margin-bottom:1rem;font-size:2.5rem}.joule-value{color:var(--accent-amber);font-size:1.5rem;font-weight:700;font-family:var(--font-mono)}.joule-desc{color:var(--text-secondary);margin-top:.5rem;font-size:.9rem}.series-pill a{color:inherit;align-items:center;gap:.4rem;text-decoration:none;display:flex}.series-pill.completed{cursor:pointer}.series-pill.completed:before{content:"✓";color:#10b981b3;font-weight:700}@keyframes wire-flow{0%{background-position:0 0}to{background-position:20px 0}}@keyframes binary-wave{0%{transform:translate(0)}to{transform:translate(-50%)}}@keyframes battery-shimmer{0%{opacity:.5}to{opacity:1}}@keyframes elastic-snap{0%{transform:scaleX(1.5)}50%{transform:scaleX(.8)}to{transform:scaleX(1)}}@keyframes ball-drop{0%{transform:translateY(-20px)}to{transform:translateY(20px)}}@keyframes probe-pulse{0%{box-shadow:inset 0 0 5px #10b9811a}to{box-shadow:inset 0 0 15px #10b98166}}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@keyframes bounce-right{0%{transform:translate(-60%)}to{transform:translate(-40%)}}.app-container{flex-direction:column;min-height:100vh;display:flex}.top-navbar-left{flex:1;align-items:center;gap:1.25rem;display:flex}.top-lesson-switcher{align-items:center;gap:.5rem;margin-left:.5rem;display:flex}.top-lesson-btn{background:var(--bg-card);color:var(--text-secondary);border:1px solid var(--border-subtle);border-radius:var(--radius-full);cursor:pointer;transition:all var(--transition-fast);align-items:center;gap:.4rem;padding:.4rem .85rem;font-size:.82rem;font-weight:600;display:inline-flex}.top-lesson-btn.active{border-color:var(--accent-cyan);color:var(--accent-cyan);background:#38bdf826;box-shadow:0 0 12px #38bdf840}.top-lesson-btn.catalog-btn{color:var(--accent-amber);background:#f59e0b1a;border-color:#f59e0b59}.top-lesson-btn.catalog-btn:hover{border-color:var(--accent-amber);background:#f59e0b33}.mobile-sidebar-toggle-btn{background:var(--bg-card);border:1px solid var(--border-subtle);color:var(--text-primary);border-radius:var(--radius-sm);cursor:pointer;padding:.3rem .6rem;font-size:1.2rem;display:none}.sidebar-catalog-link-btn{color:var(--accent-cyan);cursor:pointer;border-radius:var(--radius-sm);transition:all var(--transition-fast);background:0 0;border:none;padding:.2rem .4rem;font-size:.78rem;font-weight:600}.sidebar-catalog-link-btn:hover{color:var(--text-primary);background:#38bdf826}.sidebar-course-list{flex-direction:column;gap:.6rem;margin-bottom:1.25rem;display:flex}.sidebar-course-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);padding:.7rem .85rem;text-decoration:none;display:block}.sidebar-course-card:hover:not(.disabled){border-color:var(--accent-cyan);background:var(--bg-card-hover);transform:translate(3px)}.sidebar-course-card.disabled{opacity:.55;cursor:not-allowed}.sidebar-course-card-top{align-items:center;gap:.65rem;display:flex}.sidebar-course-icon{border-radius:var(--radius-sm);background:#00000040;justify-content:center;align-items:center;width:32px;height:32px;font-size:1.35rem;display:flex}.sidebar-course-info{flex:1;min-width:0}.sidebar-course-title{color:var(--text-primary);white-space:nowrap;text-overflow:ellipsis;font-size:.86rem;font-weight:700;overflow:hidden}.sidebar-course-subtitle{color:var(--text-secondary);white-space:nowrap;text-overflow:ellipsis;font-size:.74rem;overflow:hidden}.sidebar-course-meta{border-top:1px dashed #ffffff12;justify-content:space-between;align-items:center;margin-top:.45rem;padding-top:.35rem;display:flex}.sidebar-course-tag{font-size:.7rem;font-family:var(--font-mono);color:var(--accent-cyan);border-radius:var(--radius-sm);background:#38bdf81a;padding:.1rem .4rem}.sidebar-course-status{font-size:.72rem;font-weight:600}.sidebar-mobile-header{border-bottom:1px solid var(--border-subtle);justify-content:space-between;align-items:center;margin-bottom:1rem;padding-bottom:.75rem;display:none}.sidebar-mobile-title{font-size:1rem;font-weight:700}.sidebar-mobile-close{color:var(--text-secondary);cursor:pointer;background:0 0;border:none;padding:.2rem .5rem;font-size:1.25rem}.sidebar-mobile-backdrop{-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);z-index:998;background:#000000a6;display:none;position:fixed;inset:0}.catalog-modal-backdrop{-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);z-index:1100;background:#0a0e17d9;justify-content:center;align-items:center;padding:1.5rem;animation:.2s modal-fade-in;display:flex;position:fixed;inset:0}@keyframes modal-fade-in{0%{opacity:0}to{opacity:1}}.catalog-modal{background:var(--bg-secondary);border:1px solid var(--border-subtle);border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);flex-direction:column;width:100%;max-width:1060px;max-height:90vh;display:flex;overflow:hidden}.catalog-modal-header{border-bottom:1px solid var(--border-subtle);background:var(--bg-card);justify-content:space-between;align-items:flex-start;padding:1.5rem 2rem;display:flex}.catalog-modal-title-wrap{flex:1;padding-right:1.5rem}.catalog-modal-badge{color:var(--accent-cyan);text-transform:uppercase;letter-spacing:.05em;margin-bottom:.35rem;font-size:.78rem;font-weight:700;display:inline-block}.catalog-modal-title{color:var(--text-primary);margin-bottom:.25rem;font-size:1.5rem;font-weight:800}.catalog-modal-subtitle{color:var(--text-secondary);font-size:.88rem}.catalog-modal-close{background:var(--bg-input);border:1px solid var(--border-subtle);color:var(--text-secondary);border-radius:var(--radius-full);cursor:pointer;width:36px;height:36px;transition:all var(--transition-fast);justify-content:center;align-items:center;font-size:1.2rem;display:flex}.catalog-modal-close:hover{background:var(--accent-rose);color:#fff;border-color:var(--accent-rose)}.catalog-search-bar{background:var(--bg-primary);border-bottom:1px solid var(--border-subtle);align-items:center;gap:.75rem;padding:1rem 2rem;display:flex}.search-icon{opacity:.85;font-size:1.1rem;line-height:1}.catalog-search-input{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-md);color:var(--text-primary);transition:border-color var(--transition-fast);outline:none;flex:1;padding:.65rem 1rem;font-size:.95rem}.catalog-search-input:focus{border-color:var(--accent-cyan);box-shadow:0 0 0 3px #38bdf833}.search-clear-btn{color:var(--text-muted);cursor:pointer;background:0 0;border:none;padding:.2rem .5rem;font-size:1.1rem}.catalog-grid{grid-template-columns:repeat(auto-fit,minmax(460px,1fr));gap:1.25rem;padding:1.5rem 2rem;display:grid;overflow-y:auto}.catalog-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);transition:all var(--transition-fast);flex-direction:column;padding:1.4rem;display:flex}.catalog-card:hover:not(.upcoming){border-color:var(--accent-cyan);box-shadow:var(--shadow-md);transform:translateY(-2px)}.catalog-card.current{border-color:var(--accent-cyan);background:#38bdf80d}.catalog-card.upcoming{opacity:.65;background:#00000026}.catalog-card-header{align-items:flex-start;gap:1rem;margin-bottom:.75rem;display:flex}.catalog-card-icon{background:var(--bg-input);border-radius:var(--radius-md);border:2px solid;flex-shrink:0;justify-content:center;align-items:center;width:52px;height:52px;font-size:2rem;display:flex}.catalog-card-title-box{flex:1}.catalog-card-meta{flex-wrap:wrap;gap:.5rem;margin-bottom:.35rem;display:flex}.catalog-card-title{color:var(--text-primary);font-size:1.15rem;font-weight:700;line-height:1.3}.catalog-card-meaning{color:var(--text-secondary);margin-top:.2rem;font-size:.8rem}.catalog-card-desc{color:var(--text-secondary);margin-bottom:1rem;font-size:.88rem;line-height:1.6}.catalog-section-preview{background:var(--bg-input);border:1px solid var(--border-subtle);border-radius:var(--radius-sm);margin-bottom:1.25rem;padding:.75rem 1rem}.catalog-section-preview-title{color:var(--text-muted);text-transform:uppercase;margin-bottom:.5rem;font-size:.78rem;font-weight:700}.catalog-section-list{flex-direction:column;gap:.35rem;max-height:140px;display:flex;overflow-y:auto}.catalog-section-item{align-items:center;gap:.5rem;font-size:.82rem;display:flex}.catalog-sec-num{font-family:var(--font-mono);color:var(--accent-cyan);font-size:.75rem;font-weight:700}.catalog-sec-title{color:var(--text-primary);white-space:nowrap;text-overflow:ellipsis;flex:1;overflow:hidden}.catalog-sec-badge{color:var(--accent-cyan);border-radius:var(--radius-sm);white-space:nowrap;background:#38bdf81f;padding:.1rem .4rem;font-size:.7rem}.catalog-card-footer{border-top:1px solid var(--border-subtle);justify-content:space-between;align-items:center;margin-top:auto;padding-top:.75rem;display:flex}.catalog-card-stats-text{color:var(--text-muted);font-size:.8rem}.btn-current-active{background:var(--accent-emerald)!important;box-shadow:0 2px 10px var(--accent-emerald-glow)!important}.catalog-empty-search{text-align:center;color:var(--text-secondary);padding:3rem}.lesson-next-bridge-card{border-radius:var(--radius-lg);background:linear-gradient(135deg,#38bdf81a,#f59e0b1a);border:1px solid #38bdf84d;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:2rem;margin:2.5rem 0 1.5rem;padding:2rem;display:flex}.bridge-card-left{flex:1;min-width:280px}.bridge-tag{color:var(--accent-cyan);letter-spacing:.05em;margin-bottom:.35rem;font-size:.8rem;font-weight:700}.bridge-title{color:var(--text-primary);margin-bottom:.5rem;font-size:1.4rem;font-weight:800}.bridge-desc{color:var(--text-secondary);font-size:.92rem;line-height:1.6}.bridge-action-btn{white-space:nowrap;padding:.75rem 1.6rem;font-size:1rem}.summary-cards-grid{grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1rem;margin:1.5rem 0;display:grid}.summary-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md);text-align:center;transition:transform var(--transition-fast);padding:1.25rem}.summary-card:hover{border-color:var(--accent-cyan);transform:translateY(-2px)}.summary-card-icon{margin-bottom:.5rem;font-size:2rem}.summary-card-title{color:var(--text-primary);margin-bottom:.35rem;font-size:1rem;font-weight:700}.summary-card-desc{color:var(--text-secondary);font-size:.82rem;line-height:1.5}@media (width<=1024px){.top-lesson-switcher{display:none}}@media (width<=768px){.mobile-sidebar-toggle-btn{display:block}.sidebar{z-index:999;background:var(--bg-secondary);width:290px;transition:left var(--transition-normal);box-shadow:var(--shadow-lg);position:fixed;top:0;bottom:0;left:-320px}.sidebar.mobile-open{left:0}.sidebar-mobile-header{display:flex}.sidebar-mobile-backdrop{display:block}.catalog-grid{grid-template-columns:1fr;padding:1rem}}.badge-purple{color:var(--accent-purple);background:#a855f726;border:1px solid #a855f740}.led-resistor-preset{padding:.4rem .9rem;font-family:monospace;font-size:.85rem}.led-resistor-preset.active{border-color:var(--accent-purple);color:var(--accent-purple);box-shadow:0 0 0 1px var(--accent-purple);background:#a855f71f}.resistor-power-v-preset,.resistor-power-r-preset{padding:.4rem .9rem;font-family:monospace;font-size:.85rem}.resistor-power-v-preset.active,.resistor-power-r-preset.active{border-color:var(--accent-emerald);color:var(--accent-emerald);box-shadow:0 0 0 1px var(--accent-emerald);background:#10b9811f}.badge-rose{color:var(--accent-rose);background:#f43f5e26;border:1px solid #f43f5e40}.led-color-preset{padding:.4rem .9rem;font-size:.85rem}.led-color-preset.active,.led-polarity-btn.active,.led-limit-btn.active,.shock-scenario-btn.active,.shock-body-preset.active{border-color:var(--accent-rose);color:var(--accent-rose);box-shadow:0 0 0 1px var(--accent-rose);background:#f43f5e1f}.shock-body-preset{padding:.4rem .9rem;font-size:.85rem}.mosfet-gate-btn.active{border-color:var(--accent-emerald);box-shadow:0 0 0 1px var(--accent-emerald)}.cap-rating-preset,.cap-uf-preset,.cap-v-preset{padding:.4rem .9rem;font-family:monospace;font-size:.85rem}.cap-rating-preset.active,.cap-uf-preset.active,.cap-v-preset.active{border-color:var(--accent-amber);color:var(--accent-amber);box-shadow:0 0 0 1px var(--accent-amber);background:#f59e0b1f}.scope-vdiv-preset,.scope-tdiv-preset{padding:.4rem .9rem;font-family:monospace;font-size:.85rem}.scope-vdiv-preset.active,.scope-tdiv-preset.active{border-color:var(--accent-cyan);color:var(--accent-cyan);box-shadow:0 0 0 1px var(--accent-cyan);background:#38bdf81f}.divider-r1-preset,.divider-r2-preset,.divider-load-preset{padding:.4rem .9rem;font-family:monospace;font-size:.85rem}.divider-r1-preset.active,.divider-r2-preset.active,.divider-load-preset.active{border-color:var(--accent-purple);color:var(--accent-purple);box-shadow:0 0 0 1px var(--accent-purple);background:#a78bfa1f}.xfmr-input-btn.active{border-color:var(--accent-amber);color:var(--accent-amber);box-shadow:0 0 0 1px var(--accent-amber);background:#f59e0b1f}.rectifier-mode-preset.active,.rectifier-cap-preset.active,.rectifier-load-preset.active{border-color:var(--accent-cyan);color:var(--accent-cyan);box-shadow:0 0 0 1px var(--accent-cyan);background:#38bdf81f}.rectifier-cap-preset,.rectifier-load-preset{font-family:monospace;font-size:.85rem}.dropout-reg-preset.active{border-color:var(--accent-emerald);color:var(--accent-emerald);box-shadow:0 0 0 1px var(--accent-emerald);background:#10b9811f}.opamp-r1-preset,.opamp-r2-preset,.opamp-vs-preset{padding:.4rem .9rem;font-family:monospace;font-size:.85rem}.opamp-r1-preset.active,.opamp-r2-preset.active,.opamp-vs-preset.active{border-color:var(--accent-purple);color:var(--accent-purple);box-shadow:0 0 0 1px var(--accent-purple);background:#a78bfa1f}@media (width<=768px){.top-navbar{height:auto;min-height:52px;padding:.35rem .7rem}.top-navbar-left{flex:1;gap:.5rem;min-width:0}.brand-wrapper{flex:1;min-width:0}.brand-icon{font-size:1.2rem}.brand-title{flex-wrap:wrap;gap:.35rem;font-size:.92rem;line-height:1.2}.brand-subtitle{text-overflow:ellipsis;white-space:nowrap;vertical-align:middle;max-width:44vw;padding:1px 6px;font-size:.62rem;overflow:hidden}.nav-actions{flex-shrink:0;gap:.4rem}.nav-pill-btn{gap:0;padding:.32rem .5rem;font-size:0}.nav-pill-btn span{font-size:1rem}.main-content{padding:1.1rem .85rem 4rem}.lesson-hero{margin-bottom:2rem;padding-bottom:1.25rem}.lesson-meta-bar{gap:.4rem;margin-bottom:.75rem}.badge{padding:.18rem .5rem;font-size:.66rem}.lesson-title{overflow-wrap:break-word;word-break:break-word;font-size:1.5rem;line-height:1.3}.lesson-subtitle{font-size:.92rem;line-height:1.6}.series-overview-pills{gap:.45rem;margin-top:.9rem}.series-pill{padding:.3rem .6rem;font-size:.75rem}.lesson-section{margin-bottom:3rem;scroll-margin-top:76px}.section-heading{overflow-wrap:break-word;font-size:1.18rem}.section-index{font-size:.9rem}.section-narrative{font-size:.93rem;line-height:1.75}.lesson-content p,.lesson-content li,.lesson-content strong,.lab-caption,.quiz-question,.quiz-explanation,.bridge-desc{overflow-wrap:break-word;word-break:break-word}.css-diagram-card{margin:1.25rem 0 1.5rem;padding:1rem}.diagram-header{flex-wrap:wrap;gap:.5rem}.diagram-title{font-size:.92rem}.diagram-badge{font-size:.62rem}.math-formula-card{padding:1rem .85rem}.math-formula-body{gap:.45rem;font-size:1rem}.math-val{font-size:1.1rem}.visual-lab-card{padding:1rem .85rem}.lab-header{gap:.5rem}.lab-title{font-size:.88rem}.lab-badge{font-size:.62rem}canvas.lab-canvas{height:220px}.lab-controls-bar{gap:.6rem;padding:.6rem .7rem}.control-group{flex-wrap:wrap;gap:.45rem;width:100%}.control-label{font-size:.78rem}.control-value{font-size:.8rem}.lab-slider{flex:1;min-width:130px}.lab-caption{font-size:.78rem;line-height:1.6;display:block}.quiz-section{padding:1.25rem 1rem}.quiz-question{font-size:.92rem}.quiz-options button,.quiz-option-btn{white-space:normal;text-align:left;font-size:.85rem;line-height:1.5}.lesson-next-bridge-card{flex-direction:column;align-items:stretch;gap:1.1rem;padding:1.25rem}.bridge-card-left{min-width:0}.bridge-title{font-size:1.15rem}.bridge-desc{font-size:.85rem}.bridge-action-btn{white-space:normal;text-align:center;width:100%;padding:.65rem 1rem;font-size:.88rem}.lesson-next-bridge-card .btn-secondary{text-align:center;width:100%}.site-footer{text-align:center;flex-direction:column;gap:1rem;margin-top:2.5rem}}@media (width<=480px){.brand-subtitle{display:none}.lesson-title{font-size:1.32rem}canvas.lab-canvas{height:200px}.badge{font-size:.62rem}.series-pill{padding:.28rem .5rem;font-size:.7rem}}.deriv-chain{flex-wrap:wrap;justify-content:space-around;align-items:center;gap:1rem;display:flex}.deriv-chain-op,.deriv-chain-arrow{color:var(--text-muted);font-size:1.4rem}@media (width<=768px){.deriv-chain{flex-direction:column;justify-content:center;gap:.5rem}.deriv-chain-op{font-size:1.1rem;line-height:1.2}.deriv-chain-arrow{padding:.2rem 0;font-size:1.15rem;line-height:1;transform:rotate(90deg)}}.measure-vdiv-preset,.measure-tdiv-preset{padding:.35rem .8rem;font-family:monospace;font-size:.85rem}.measure-vdiv-preset.active,.measure-tdiv-preset.active,.coupling-mode-preset.active,.trigger-mode-preset.active,.trigger-slope-preset.active,.math-ch-btn.active{border-color:var(--accent-cyan);color:var(--accent-cyan);box-shadow:0 0 0 1px var(--accent-cyan);background:#38bdf81f}.lowpass-r-preset,.lowpass-c-preset,.pwm-cap-preset{padding:.35rem .8rem;font-family:monospace;font-size:.85rem}.lowpass-r-preset.active,.lowpass-c-preset.active,.pwm-cap-preset.active{border-color:var(--accent-cyan);color:var(--accent-cyan);box-shadow:0 0 0 1px var(--accent-cyan);background:#38bdf81f}.highpass-r-preset,.highpass-c-preset,.hpwave-preset{padding:.35rem .8rem;font-family:monospace;font-size:.85rem}.highpass-r-preset.active,.highpass-c-preset.active,.hpwave-preset.active{border-color:var(--accent-purple);color:var(--accent-purple);box-shadow:0 0 0 1px var(--accent-purple);background:#a78bfa1f}.zener-wave-preset{padding:.35rem .8rem;font-family:monospace;font-size:.85rem}.zener-wave-preset.active{border-color:var(--accent-rose);color:var(--accent-rose);box-shadow:0 0 0 1px var(--accent-rose);background:#f43f5e1f}.comp-vs-preset{padding:.35rem .8rem;font-family:monospace;font-size:.85rem}.comp-vs-preset.active{border-color:var(--accent-emerald);color:var(--accent-emerald);box-shadow:0 0 0 1px var(--accent-emerald);background:#10b9811f}.top-lesson-switcher{flex-shrink:1;min-width:0;overflow:hidden}.top-lesson-btn{white-space:nowrap;flex-shrink:0}.brand-wrapper{flex-shrink:0}.top-navbar-left{min-width:0}.top-lesson-switcher{scrollbar-width:none;min-width:0;overflow-x:auto}.top-lesson-switcher::-webkit-scrollbar{display:none}.nav-actions{flex-shrink:0}[data-theme=light]{--bg-primary:#fff;--bg-secondary:#fafafa;--bg-card:#fff;--bg-card-hover:#f5f5f5;--bg-input:#f5f5f5;--border-subtle:#e5e5e5;--border-active:#171717;--text-primary:#171717;--text-secondary:#525252;--text-muted:#a3a3a3;--text-code:#171717;--accent-cyan:#171717;--accent-blue:#171717;--accent-amber:#525252;--accent-emerald:#171717;--accent-rose:#171717;--accent-purple:#525252;--accent-amber-glow:#0000;--accent-emerald-glow:#0000;--accent-rose-glow:#0000;--shadow-sm:none;--shadow-md:none;--shadow-lg:0 8px 30px #00000014;--shadow-glow-cyan:none;--shadow-glow-amber:none;--radius-sm:4px;--radius-md:6px;--radius-lg:10px}[data-theme=dark]{--bg-primary:#0a0a0a;--bg-secondary:#111;--bg-card:#141414;--bg-card-hover:#1c1c1c;--bg-input:#0f0f0f;--border-subtle:#262626;--border-active:#ededed;--text-primary:#ededed;--text-secondary:#a3a3a3;--text-muted:#737373;--text-code:#ededed;--accent-cyan:#ededed;--accent-blue:#ededed;--accent-amber:#a3a3a3;--accent-emerald:#ededed;--accent-rose:#ededed;--accent-purple:#a3a3a3;--accent-amber-glow:#0000;--accent-emerald-glow:#0000;--accent-rose-glow:#0000;--shadow-sm:none;--shadow-md:none;--shadow-lg:0 8px 30px #00000080;--shadow-glow-cyan:none;--shadow-glow-amber:none;--radius-sm:4px;--radius-md:6px;--radius-lg:10px}body{letter-spacing:0}::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}.top-navbar{background:var(--bg-primary);border-bottom:1px solid var(--border-subtle);-webkit-backdrop-filter:none}[data-theme=dark] .top-navbar{-webkit-backdrop-filter:blur(12px);background:#0a0a0aeb}[data-theme=light] .top-navbar{-webkit-backdrop-filter:blur(12px);background:#ffffffeb}.brand-icon{box-shadow:none;background:0 0;font-size:1.3rem}.nav-pill-btn{border:1px solid var(--border-subtle);color:var(--text-secondary);box-shadow:none;background:0 0}.nav-pill-btn:hover{border-color:var(--border-active);color:var(--text-primary);box-shadow:none;transform:none}.reading-progress-bar{background:var(--text-primary)}.top-lesson-btn{border:1px solid var(--border-subtle);color:var(--text-secondary);background:0 0;font-weight:500}.top-lesson-btn:hover{border-color:var(--border-active);color:var(--text-primary);transform:none}.top-lesson-btn.active{background:var(--text-primary);border-color:var(--text-primary);color:var(--bg-primary);box-shadow:none}.top-lesson-btn.catalog-btn{border-color:var(--border-subtle);color:var(--text-secondary);background:0 0}.top-lesson-btn.catalog-btn:hover{border-color:var(--border-active);color:var(--text-primary);background:0 0}.sidebar{background:var(--bg-secondary);border-right:1px solid var(--border-subtle)}.series-badge-card{border:1px solid var(--border-subtle);border-radius:var(--radius-md);background:0 0}.series-badge-card:before{display:none}.toc-link{color:var(--text-secondary);border-left:2px solid #0000}.toc-link:hover{color:var(--text-primary);background:var(--bg-card-hover)}.toc-link.active{color:var(--text-primary);border-left-color:var(--text-primary);background:var(--bg-card-hover)}.toc-link.active .toc-num{color:var(--text-primary)}.stat-box{border:1px solid var(--border-subtle);box-shadow:none;background:0 0}.stat-val{color:var(--text-primary)}.lesson-title{background:0 0;-webkit-background-clip:initial;-webkit-text-fill-color:currentColor;color:var(--text-primary);letter-spacing:-.03em;font-weight:700}[data-theme=light] .lesson-title{background:0 0;-webkit-background-clip:initial;-webkit-text-fill-color:currentColor}.badge,.badge-cyan,.badge-amber,.badge-emerald,.badge-red,.badge-blue{border:1px solid var(--border-subtle);color:var(--text-secondary);box-shadow:none;background:0 0;font-weight:500}.series-pill{border:1px solid var(--border-subtle);color:var(--text-secondary);box-shadow:none;background:0 0}.series-pill:hover{border-color:var(--border-active);color:var(--text-primary);transform:none}.series-pill.active{background:var(--text-primary);border-color:var(--text-primary);color:var(--bg-primary);box-shadow:none}.section-index{border:1px solid var(--border-subtle);color:var(--text-muted);box-shadow:none;background:0 0}.strong-term{color:var(--text-primary);border-bottom:1px solid var(--text-muted);background:0 0;padding:0}.visual-lab-card{background:var(--bg-card);border:1px solid var(--border-subtle);box-shadow:none;border-radius:var(--radius-md)}.visual-lab-card:hover{box-shadow:none;border-color:var(--border-active);transform:none}.lab-badge{border:1px solid var(--border-subtle);color:var(--text-secondary);box-shadow:none;background:0 0;font-weight:500}.lab-title{color:var(--text-primary)}.lab-canvas-container{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);background:var(--bg-input)}.lab-slider{accent-color:var(--text-primary)}.control-label{color:var(--text-muted)}.control-value{color:var(--text-primary);font-family:var(--font-mono)}.lab-caption{border-top:1px solid var(--border-subtle);padding-top:.75rem}.measure-vdiv-preset.active,.measure-tdiv-preset.active,.coupling-mode-preset.active,.trigger-mode-preset.active,.trigger-slope-preset.active,.math-ch-btn.active,.lowpass-r-preset.active,.lowpass-c-preset.active,.pwm-cap-preset.active,.highpass-r-preset.active,.highpass-c-preset.active,.hpwave-preset.active,.zener-wave-preset.active,.comp-vs-preset.active,.scope-vdiv-preset.active,.scope-tdiv-preset.active,.scope-wave-preset.active,.scope-bw-preset.active,.divider-r1-preset.active,.divider-r2-preset.active,.divider-load-preset.active,.xfmr-input-btn.active,.rectifier-type-preset.active,.rectifier-cap-preset.active,.rectifier-load-preset.active,.dropout-reg-preset.active,.opamp-r1-preset.active,.opamp-r2-preset.active,.opamp-vs-preset.active,.seg-btn.active{background:var(--text-primary)!important;border-color:var(--text-primary)!important;color:var(--bg-primary)!important;box-shadow:none!important}.btn-primary{background:var(--text-primary);color:var(--bg-primary);border:1px solid var(--text-primary);box-shadow:none;font-weight:500}.btn-primary:hover{filter:none;opacity:.82;transform:none}.btn-secondary{border:1px solid var(--border-subtle);color:var(--text-primary);background:0 0}.btn-secondary:hover{background:var(--bg-card-hover);border-color:var(--border-active)}.btn-danger{border:1px solid var(--text-primary);color:var(--text-primary);box-shadow:none;background:0 0}.btn-danger:hover{background:var(--text-primary);color:var(--bg-primary);filter:none}.quiz-section{border:1px solid var(--border-subtle);background:var(--bg-card);box-shadow:none;border-radius:var(--radius-md)}.quiz-title{color:var(--text-primary)}.quiz-option-btn{border:1px solid var(--border-subtle);color:var(--text-secondary);background:0 0}.quiz-option-btn:hover{border-color:var(--border-active);color:var(--text-primary);transform:none}.quiz-option-btn.correct{font-weight:600;background:var(--text-primary)!important;border-color:var(--text-primary)!important;color:var(--bg-primary)!important}.quiz-option-btn.wrong{text-decoration:line-through;border-color:var(--text-muted)!important;color:var(--text-muted)!important;background:0 0!important}.quiz-explanation{background:var(--bg-input);border-left:2px solid var(--text-primary);color:var(--text-secondary)}.math-formula-card{background:var(--bg-card);border:1px solid var(--border-subtle);box-shadow:none;border-radius:var(--radius-md)}.math-formula-tag{color:var(--text-muted);letter-spacing:.08em}.math-highlight{color:var(--text-primary);border:1px solid var(--border-subtle);box-shadow:none;background:0 0}.math-op,.math-operator{color:var(--text-muted)}.math-val{color:var(--text-primary)}.math-subtext{color:var(--text-muted);border-top:1px solid var(--border-subtle)}.css-diagram-card{background:var(--bg-card);border:1px solid var(--border-subtle);box-shadow:none;border-radius:var(--radius-md)}.css-diagram-card:hover{box-shadow:none;border-color:var(--border-active);transform:none}.diagram-badge{border:1px solid var(--border-subtle);color:var(--text-secondary);background:0 0}.diagram-title{color:var(--text-primary)}.deriv-chain .math-highlight,.deep-dive-card{box-shadow:none}.deep-dive-card{background:var(--bg-card);border:1px solid var(--border-subtle);border-radius:var(--radius-md)}.deep-dive-header{border-bottom:1px solid var(--border-subtle);background:0 0}.scale-card{background:var(--bg-card);box-shadow:none}.scale-card:hover,.scale-card.selected{border-color:var(--border-active);box-shadow:none;transform:none}.scale-card.danger:hover,.scale-card.danger.selected{border-color:var(--border-active);box-shadow:none}.scale-val,.scale-card.danger .scale-val{color:var(--text-primary)}.lesson-next-bridge-card{background:var(--bg-card);border:1px solid var(--border-subtle);box-shadow:none;border-radius:var(--radius-md)}.bridge-tag{color:var(--text-muted);letter-spacing:.08em}.bridge-title{color:var(--text-primary)}.bridge-desc{color:var(--text-secondary)}.site-footer{border-top:1px solid var(--border-subtle);color:var(--text-muted)}.footer-next-btn{border:1px solid var(--border-subtle);color:var(--text-secondary);box-shadow:none;background:0 0}.footer-next-btn:hover{border-color:var(--border-active);color:var(--text-primary);transform:none}.catalog-modal-overlay,.modal-overlay{-webkit-backdrop-filter:none;background:#0006}.catalog-modal,.modal-card{border:1px solid var(--border-subtle);box-shadow:var(--shadow-lg);border-radius:var(--radius-lg)}.catalog-card-icon{filter:grayscale();border-color:var(--border-subtle)!important}.tag-gray,.tag-copper,.material-badge-tag{border:1px solid var(--border-subtle);color:var(--text-secondary);background:0 0}.visual-lab-card,.css-diagram-card,.scale-card,.series-pill,.top-lesson-btn,.btn-primary,.btn-secondary,.toc-link{transition:border-color .15s,color .15s,background-color .15s,opacity .15s}.nav-actions{flex-shrink:0;gap:.5rem;display:flex}.nav-pill-btn{white-space:nowrap}@media (width<=1400px){.brand-subtitle{display:none}}.sidebar-course-card{border:1px solid var(--border-subtle);border-radius:var(--radius-sm);background:0 0;padding:.6rem .75rem}.sidebar-course-card:hover:not(.disabled){border-color:var(--border-active);transform:none}.sidebar-course-card.active{border-color:var(--text-primary);background:var(--bg-input);box-shadow:none}.sidebar-course-icon{font-family:var(--font-mono);color:var(--text-muted);border:1px solid var(--border-subtle);border-radius:var(--radius-sm);background:0 0;flex-shrink:0;width:30px;height:30px;font-size:.8rem;font-weight:600}.sidebar-course-card.active .sidebar-course-icon{color:var(--text-primary);border-color:var(--text-primary)}.sidebar-course-title{color:var(--text-primary);font-size:.85rem;font-weight:600}.sidebar-course-subtitle{color:var(--text-muted);font-size:.75rem}.sidebar-course-tag{color:var(--text-muted);border:1px solid var(--border-subtle);background:0 0;font-size:.68rem}.sidebar-course-status.ready{color:var(--text-primary)}.sidebar-course-status.upcoming{color:var(--text-muted)}.sidebar-section-title{color:var(--text-muted);letter-spacing:.06em;text-transform:uppercase;font-size:.78rem}.sidebar-catalog-link-btn{border:1px solid var(--border-subtle);color:var(--text-secondary);box-shadow:none;background:0 0}.sidebar-catalog-link-btn:hover{border-color:var(--border-active);color:var(--text-primary)}.brand-icon,.nav-pill-btn,.top-lesson-btn,.badge,.series-pill,.lab-badge,.diagram-badge,.quiz-title,.footer-next-btn,.btn-primary,.btn-secondary,.lesson-next-bridge-card,.site-footer,.quiz-explanation,.catalog-modal,.sidebar-mobile-header{filter:grayscale()}
