:root{color-scheme:dark;--bg:#0a1220;--panel:#111e30;--line:#26364b;--muted:#98aabe;--text:#ecf3fb;--cyan:#54d9e6;--orange:#f2b566;--radius:14px;font-family:Inter,Segoe UI,Arial,sans-serif;font-size:16px}*{box-sizing:border-box}body{margin:0;background:radial-gradient(ellipse at 76% 0%,#12263a 0,transparent 42%),var(--bg);color:var(--text);line-height:1.55}a{color:inherit;text-decoration:none}a:hover{color:var(--cyan)}button,input,select,textarea{font:inherit}button,select{cursor:pointer}button{min-height:44px;border:1px solid var(--line);border-radius:8px;background:#17273b;color:var(--text);padding:9px 15px;font-size:.875rem;font-weight:600}button:hover{border-color:#7191aa;background:#20374a}button.active{color:var(--cyan);background:#163340;border-color:#367681}button:disabled{opacity:.5;cursor:not-allowed}input[type=number],select,textarea{background:#0c1828;color:var(--text);border:1px solid #364960;border-radius:7px;padding:8px;min-height:44px;max-width:100%}input[type=number]{width:85px;font-variant-numeric:tabular-nums}input[type=range]{width:100%;accent-color:var(--cyan);height:24px;margin:12px 0;cursor:pointer}input[type=checkbox]{accent-color:var(--cyan);width:17px;height:17px}label{font-size:.875rem}:focus-visible{outline:2px solid var(--cyan);outline-offset:4px}.skip{position:fixed;top:-80px;z-index:20;padding:14px;background:var(--panel)}.skip:focus{top:0}.site-header{height:78px;display:flex;align-items:center;gap:23px;border-bottom:1px solid var(--line);padding:0 max(24px,calc((100vw - 1440px)/2));font-size:.875rem}.site-header img{display:block;object-fit:contain}.brand-divider{width:1px;height:25px;background:var(--line)}.back{margin-left:auto;color:var(--muted)}main{max-width:1440px;margin:auto;padding:0 24px}.breadcrumbs{display:flex;flex-wrap:wrap;gap:9px;font-size:.75rem;color:var(--muted);padding-top:23px}.intro{display:flex;align-items:center;justify-content:space-between;padding:25px 0 28px;gap:20px}.eyebrow{font-size:.6875rem;font-weight:700;letter-spacing:.16em;color:var(--cyan)}.eyebrow span{color:#53657d;margin:0 9px}h1{font-size:clamp(1.65rem,2.8vw,2.65rem);font-weight:650;letter-spacing:-.04em;line-height:1.2;margin:10px 0 12px}h1 span{display:block;font-size:.6em;font-weight:450;letter-spacing:-.02em;color:#c0cddd;margin-top:8px}.intro p{color:var(--muted);margin:0;font-size:.9375rem}.grade{font-size:.8125rem;color:var(--cyan);border:1px solid #315564;border-radius:30px;white-space:nowrap;padding:8px 15px}h2{font-size:1.15rem;line-height:1.35;margin:0}h3{font-size:1.1rem;line-height:1.4}p{color:var(--muted)}.modebar{display:flex;gap:4px;border-bottom:1px solid var(--line);margin-bottom:18px;align-items:center;flex-wrap:wrap}.modebar button{background:none;border:0;border-bottom:2px solid transparent;border-radius:0;padding:14px 18px;color:var(--muted)}.modebar button.active{color:var(--cyan);border-color:var(--cyan)}.mode-caption{font-size:.625rem;letter-spacing:.13em;margin-left:auto;color:#768b9f}.workspace{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:0 18px}.scene-panel,.parameters,.graph-panel,.formula-panel{background:linear-gradient(135deg,#122136,#101b2a);border:1px solid var(--line);border-radius:var(--radius);min-width:0;overflow:hidden}.panel-heading{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:18px 22px;font-size:.8125rem}.panel-heading h2{font-size:.9375rem;font-weight:600}.panel-heading>span:last-child{font-size:.6875rem;color:var(--muted)}.status-dot{display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--cyan);margin-right:7px}.scene-wrap{height:277px;position:relative;background:linear-gradient(#101f34,#172b40)}canvas{display:block;width:100%;touch-action:pan-y}#scene{height:100%}.scene-tag{position:absolute;left:24px;top:12px;font-size:.625rem;letter-spacing:.15em;color:#7e95af;pointer-events:none}.scene-tip{position:absolute;left:20px;bottom:10px;font-size:.75rem;background:#07101e;padding:8px;border:1px solid var(--cyan);pointer-events:none}.instruments{display:grid;grid-template-columns:repeat(4,1fr);padding:20px 8px;border-top:1px solid var(--line)}.instruments>div{padding:0 20px;border-right:1px solid var(--line)}.instruments>div:last-child{border:0}.instruments span{display:block;font-size:.75rem;color:var(--muted)}.instruments i{margin-left:5px;color:#becbd8}.instruments strong{font-size:1.8rem;font-weight:500;font-variant-numeric:tabular-nums;white-space:nowrap;letter-spacing:-.03em}.instruments small{font-size:.8125rem;color:var(--muted)}.cyan{color:var(--cyan)}.orange{color:var(--orange)}.transport{display:flex;align-items:center;gap:8px;padding:0 20px 20px;flex-wrap:wrap}.primary{background:var(--cyan);color:#08242c;border-color:var(--cyan)}.primary:hover{background:#81e8ee}.speed{margin-left:auto;display:flex;gap:8px;align-items:center;color:var(--muted);font-size:.75rem}.speed select{padding:6px}.parameters{padding-bottom:12px}.parameters .panel-heading{padding:18px}.parameter{padding:8px 18px 0}.parameter-top{display:flex;align-items:center;justify-content:space-between;gap:5px}.parameter-top label{font-size:.8125rem}.parameter-top label span{color:var(--muted);font-size:.75rem}.parameter input[type=number]{min-height:34px;padding:5px 8px;width:73px;font-size:.875rem}.range-limits{display:flex;justify-content:space-between;color:#8195ab;font-size:.625rem;margin-top:-8px}.options{padding:14px 18px 0;display:grid;gap:8px}.options label{display:flex;align-items:center;gap:7px;font-size:.75rem}.micro{font-size:.75rem;margin:10px 0;line-height:1.65}.parameters .micro{padding:0 18px}.text-button{background:none;border:0;color:var(--cyan);margin:0 3px}.error{font-size:.75rem;color:#ffbe9d;padding:0 18px;margin:0}.timeline{grid-column:1/-1;padding:20px 3px 25px}.timeline>div{display:flex;justify-content:space-between;font-size:.75rem;color:var(--muted)}.timeline label{font-size:.8125rem;color:var(--text)}.timeline input{margin:8px 0}.timeline-ends{font-size:.625rem!important}.analysis-grid{display:grid;grid-template-columns:1.2fr 1fr;gap:18px}.graph-tabs{display:flex;gap:4px}.graph-tabs button{min-height:32px;padding:4px 13px;font-family:Georgia,serif}.graph-panel canvas{height:245px}.graph-note{font-size:.75rem;padding:0 22px}.compare-actions{display:flex;gap:6px;padding:0 22px;flex-wrap:wrap}.compare-actions button{font-size:.75rem;min-height:36px}.graph-panel>.micro{padding:0 22px 10px}.formula-panel>.equation{font-family:Georgia,serif;font-style:italic;font-size:1.6rem;padding:0 23px;margin:8px 0;color:#d5e8f6}.substitution{font-size:.8125rem;font-variant-numeric:tabular-nums;padding:0 23px;margin:6px 0 18px;min-height:22px}.formula-panel>.micro{padding:0 23px}.formula-panel .muted{font-size:.5625rem}.explanation{margin:20px 23px;padding:15px 0 0;border-top:1px solid var(--line)}.explanation h3{margin:6px 0;font-size:.9375rem}.explanation p{font-size:.8125rem;margin:0}.flash{background:#345e57;color:#a8fff1;border-radius:4px}.activity{margin-top:22px;border:1px solid var(--line);border-radius:var(--radius);padding:25px;background:#101c2c}.activity h2{margin:6px 0 10px}.activity p{max-width:900px}.activity select{max-width:100%;width:auto}.activity input{margin:5px}.activity button{margin:5px 3px}.activity .question-row{display:flex;flex-wrap:wrap;gap:10px;align-items:center}.activity textarea{width:100%;min-height:90px;resize:vertical}.task-picker{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin:15px 0}.task-picker button{text-align:left;margin:0;font-size:.8125rem}.task-picker small{margin-right:10px;color:var(--cyan)}.result{padding:22px;border:1px solid #467f75;background:#12342e;border-radius:12px;margin-top:15px;color:#c0f5e3}.experiment-next{display:flex;justify-content:space-between;align-items:center;gap:20px;margin:25px 0;padding:25px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.experiment-next h3{margin:5px 0}.theory,.faq,.related,.glossary{padding:35px 0;border-bottom:1px solid var(--line)}.section-intro h2{font-size:1.7rem;margin:8px 0 25px}.theory-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:25px}.theory-grid h2{font-size:1rem}.theory-grid p{font-size:.9375rem}.glossary h2,.faq h2,.related h2{margin-bottom:20px}details{border-bottom:1px solid var(--line);padding:13px 0}summary{cursor:pointer;min-height:30px;color:#dce5ef}details p{margin:10px 0;max-width:900px}.glossary #glossary{display:grid;grid-template-columns:repeat(3,1fr);gap:0 22px}.glossary>label{margin-right:12px}.glossary>input{margin:16px 12px 0 0}.science-map{border-left:2px solid #387886;padding:0 0 12px 25px;margin-bottom:35px}.current-node{color:var(--cyan)}#related-labs,#related-articles{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}.future{border:1px solid var(--line);padding:14px 18px;border-radius:8px;color:#a6b4c5;font-size:.875rem}.future small{display:block;color:#778a9f}.science-map p{font-size:.875rem}.science-map p span{margin:0 12px}footer{max-width:1440px;margin:auto;padding:30px 24px;display:flex;gap:25px;justify-content:space-between;color:var(--muted);font-size:.75rem}table{border-collapse:collapse;width:100%;max-width:700px}td,th{padding:7px;text-align:left;border-bottom:1px solid var(--line)}table input{width:95px!important}.table-wrap{overflow:auto}#thrust-control{padding:10px 18px}#thrust-control .micro{padding:0}.mode-caption{display:none}@media(min-width:1500px){.scene-wrap{height:320px}.mode-caption{display:block}}@media(max-width:1050px){.workspace{grid-template-columns:minmax(0,1fr) 275px}.instruments>div{padding:0 10px}.instruments strong{font-size:1.45rem}.transport{padding:0 12px 18px}.transport button{padding:8px;font-size:.75rem}.theory-grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:760px){main{padding:0 16px}.site-header{height:65px;padding:0 16px;gap:13px}.site-header img{width:145px;height:35px}.site-header>span{display:none}.back{font-size:.75rem}.breadcrumbs{font-size:.6875rem}.intro{padding:23px 0;align-items:flex-start}.grade{display:none}h1{font-size:1.9rem}.intro p{font-size:.875rem}.modebar{gap:0}.modebar button{padding:10px;font-size:.75rem;flex:1 0 45%}.workspace{grid-template-columns:1fr;gap:15px}.scene-wrap{height:245px}.parameters{display:grid;grid-template-columns:1fr 1fr}.parameters>.panel-heading,.parameters>#parameters,.parameters>#thrust-control,.parameters>.error,.parameters>.text-button{grid-column:1/-1}#parameters{display:grid;grid-template-columns:1fr 1fr}.parameters .options{padding:12px}.parameters>.micro{padding:0 12px}.timeline{padding:8px 0 18px}.timeline-ends span:nth-child(2){display:none}.analysis-grid{grid-template-columns:1fr}.panel-heading{padding:16px}.instruments{padding:15px 3px}.instruments>div{padding:0 8px}.instruments strong{font-size:1.35rem}.instruments small{font-size:.625rem}.instruments span{font-size:.6875rem}.transport{padding:0 12px 15px}.speed{margin-left:0}.activity{padding:18px}.task-picker{grid-template-columns:1fr 1fr}.experiment-next{align-items:flex-start;flex-direction:column;padding:20px 0}.theory-grid,.glossary #glossary{grid-template-columns:1fr}.theory,.faq,.related,.glossary{padding:25px 0}footer{flex-direction:column;gap:10px}.graph-panel canvas{height:230px}}@media(max-width:360px){.parameters{display:block}#parameters{grid-template-columns:1fr}.instruments{grid-template-columns:1fr 1fr;gap:12px}.instruments>div:nth-child(2){border:0}.task-picker{grid-template-columns:1fr}.scene-wrap{height:220px}.transport .primary{width:100%}h1{font-size:1.7rem}.formula-panel .panel-heading{flex-wrap:wrap}.equation{font-size:1.35rem!important}.timeline output{font-size:.6875rem}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
.scene-panel{display:flex;flex-direction:column}.scene-wrap{flex:1;min-height:277px}.transport{margin-top:auto}.scene-panel .instruments{flex-shrink:0}#lab-chart{height:220px;margin:15px 0}.parameter:has(input:disabled){opacity:.65}@media(max-width:760px){.scene-wrap{flex:none;min-height:245px}}@media(max-width:360px){.scene-wrap{min-height:220px}}
.scene-wrap{height:330px;min-height:330px}#scene{position:absolute;inset:0;width:100%;height:100%}@media(max-width:760px){.scene-wrap{height:245px;min-height:245px}}@media(max-width:360px){.scene-wrap{height:220px;min-height:220px}}
.parameter input[type=range]{margin:5px 0 7px}.parameter{padding-top:5px}.parameter-top label br{display:none}.parameter-top label span{display:block}.parameters .options{gap:4px;padding-top:10px}.intro{padding-top:19px;padding-bottom:22px}.breadcrumbs{padding-top:17px}.site-header{height:68px}.scene-wrap{flex:1 1 300px;min-height:300px}.modebar{margin-bottom:14px}@media(max-width:760px){.scene-wrap{flex:none;min-height:245px}}@media(max-width:360px){.scene-wrap{min-height:220px}}