/* Scoped STUDiiO physics study; shared site chrome is preserved. */
.physics-chrome{color-scheme:light;--paper:#fff;--ink:#171715;--muted:#635f58;--line:#c5c2b9;--signal:#cf291d;--gutter:clamp(18px,3vw,52px);--sans:'Helvetica Neue',Helvetica,Arial,sans-serif;--mono:'Courier New',monospace}
.physics-chrome *{box-sizing:border-box}
.physics-chrome h1,.physics-chrome h2,.physics-chrome p,.physics-chrome figure{margin:0}
.physics-chrome button,.physics-chrome input{font:inherit;color:inherit}
.physics-chrome button{background:none;border:0;border-radius:0;cursor:pointer}
.physics-chrome a{color:inherit;text-decoration:none}
.physics-chrome button:focus-visible,.physics-chrome a:focus-visible,.physics-chrome input:focus-visible,.physics-chrome [tabindex]:focus-visible{outline:2px solid var(--signal);outline-offset:5px}
.physics-webgl{position:fixed;inset:0;z-index:0;pointer-events:none;display:block;width:100%;height:100%}
.physics-chrome{position:relative;z-index:1}
.physics-chrome .site-register{display:flex;align-items:center;justify-content:space-between;padding:20px var(--gutter) 21px;border-bottom:1px solid var(--ink);gap:20px}
.physics-chrome .wordmark{font-size:33px;font-weight:650;letter-spacing:-1.9px;line-height:1}
.physics-chrome .site-section,.physics-chrome .edition{font:10px/1.3 var(--mono)}
.physics-chrome .site-section{margin-left:auto}
.physics-chrome .site-section span{padding:0 17px;color:var(--muted)}
.physics-chrome .edition{margin-left:55px;color:var(--muted)}
.physics-chrome .page-body{padding:0 var(--gutter);max-width:1760px;margin:auto}
.physics-chrome .study-register{display:flex;justify-content:space-between;font:9px/1.4 var(--mono);color:var(--muted);margin:24px 0 38px;text-transform:uppercase}
.physics-chrome .masthead h1{font-size:clamp(38px,7.03vw,123px);font-weight:500;letter-spacing:-.072em;line-height:.89;white-space:nowrap;margin-left:-.055em}
.physics-chrome .hero-bottom{display:flex;align-items:center;justify-content:space-between;padding:26px 0 35px}
.physics-chrome .hero-bottom p{font-size:19px;letter-spacing:-.45px}
.physics-chrome .hero-bottom>span{font:9px var(--mono);color:var(--muted)}
.physics-chrome .hero-bottom>span span{font:24px var(--sans);margin-left:20px;color:var(--ink)}
.physics-chrome .chrome-console{display:grid;grid-template-columns:.65fr 1.2fr 1.2fr 1.2fr .65fr;gap:3.5vw;align-items:center;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:18px 0 13px;margin:0 0 48px}
.physics-chrome #chrome-play{font-size:18px;text-transform:uppercase;letter-spacing:-.04em;display:flex;align-items:center;gap:13px;text-align:left;min-height:40px;padding:0}
.physics-chrome #chrome-play i{width:8px;height:11px;border-left:3px solid var(--signal);border-right:3px solid var(--signal)}
.physics-chrome #chrome-play[aria-pressed=true] i{width:0;height:0;border-left:8px solid var(--signal);border-right:0;border-top:5px solid transparent;border-bottom:5px solid transparent}
.physics-chrome .range-control{display:block;font:9px/1.4 var(--mono)}
.physics-chrome .range-control>span{display:flex;justify-content:space-between;gap:12px}
.physics-chrome .range-control output{color:var(--muted);font-variant-numeric:tabular-nums}
.physics-chrome .range-control input{display:block;appearance:none;-webkit-appearance:none;width:100%;height:27px;background:transparent;margin:3px 0 0;cursor:ew-resize}
.physics-chrome .range-control input::-webkit-slider-runnable-track{height:1px;background:var(--muted)}
.physics-chrome .range-control input::-moz-range-track{height:1px;background:var(--muted)}
.physics-chrome .range-control input::-webkit-slider-thumb{appearance:none;-webkit-appearance:none;width:3px;height:18px;background:var(--signal);margin-top:-8px;border:0;border-radius:0}
.physics-chrome .range-control input::-moz-range-thumb{width:3px;height:18px;background:var(--signal);border:0;border-radius:0}
.physics-chrome .reset-objects{font:9px var(--mono);text-align:right;white-space:nowrap;padding:10px 0;min-height:40px}
.physics-chrome .reset-objects span{font:18px var(--sans);padding-left:13px}
.physics-chrome .equations{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:43px 30px}
.physics-chrome .equation-card{min-width:0;border-top:1px solid var(--ink);padding:13px 0 0;container-type:inline-size}
.physics-chrome .card-heading{display:flex;align-items:baseline;gap:10px;min-height:32px}
.physics-chrome .object-index{font:9px var(--mono);color:var(--muted);align-self:flex-start;padding-top:4px}
.physics-chrome h2{font-size:clamp(17px,1.72vw,26px);font-weight:400;line-height:1.05;letter-spacing:-.055em}
.physics-chrome .card-heading abbr{font:9px var(--mono);text-decoration:none;cursor:help;margin-left:auto;padding-left:5px;color:var(--signal)}
.physics-chrome .formula{height:80px;display:flex;align-items:center;font-size:7.3cqw;line-height:1;padding-bottom:2px}
.physics-chrome math{font-family:'STIX Two Math','Cambria Math','Latin Modern Math',math;math-style:normal}
.physics-chrome math[display=block]{text-align:left;margin:0}
.physics-chrome mi[mathvariant=bold]{font-style:normal;font-weight:700}
.physics-chrome .formula-fluid{font-size:5.4cqw;flex-direction:column;align-items:center;justify-content:center;gap:6px}
.physics-chrome .formula-einstein{font-size:7.1cqw}
.physics-chrome .object-space{position:relative;margin:0 -7px}
.physics-chrome .object-stage{height:auto;aspect-ratio:1.44;cursor:grab;touch-action:pan-y;outline-offset:-8px!important}
.physics-chrome .object-stage.dragging,.physics-chrome .focus-stage.dragging{cursor:grabbing}
.physics-chrome .object-register{position:absolute;left:9px;bottom:12px;color:#969087;font:8px var(--mono);pointer-events:none}
.physics-chrome .expand-object{position:absolute;bottom:0;right:0;width:40px;height:40px;display:grid;place-items:center;color:var(--muted);transition:color .2s,background .2s}
.physics-chrome .expand-object:hover{background:#ded9cf;color:var(--ink)}
.physics-chrome .caption{font-size:16px;line-height:1.25;letter-spacing:-.025em;margin:12px 0 0;min-height:42px}
.physics-chrome .caption small{display:block;font-size:11px;line-height:1.5;color:var(--muted);letter-spacing:0;margin-top:3px}
.physics-chrome .study-footer{border-top:1px solid var(--ink);margin-top:47px;padding:36px 0 24px}
.physics-chrome .closing{font-size:clamp(26px,3.2vw,54px);letter-spacing:-.065em;font-weight:400;line-height:1.08}
.physics-chrome .closing em{font-style:normal}
.physics-chrome .footer-register{display:flex;justify-content:space-between;gap:20px;font:9px/1.4 var(--mono);color:var(--muted);padding:25px 0 28px}
.physics-chrome .source-note{display:flex;justify-content:space-between;align-items:center;gap:20px;border-top:1px solid var(--line);padding-top:18px;font-size:10px;line-height:1.4;color:var(--muted)}
.physics-chrome .source-note a{white-space:nowrap}
.physics-chrome .source-note a:hover{color:var(--signal)}
.physics-chrome dialog{position:fixed;inset:0;margin:0;border:0;padding:0;width:100%;height:100%;max-width:none;max-height:none;background:var(--paper);color:var(--ink);overflow:auto}
.physics-chrome dialog::backdrop{background:var(--paper)}
.physics-chrome .focus-content{position:relative;z-index:1;min-height:100%;padding:0 var(--gutter);display:flex;flex-direction:column}
.physics-chrome .focus-header{display:flex;align-items:center;justify-content:space-between;font:10px var(--mono);padding:18px 0;border-bottom:1px solid var(--ink)}
.physics-chrome .focus-header button{font:10px var(--mono);display:flex;align-items:center;gap:23px;min-height:32px;padding:0}
.physics-chrome .focus-header button span{font:27px var(--sans)}
.physics-chrome .focus-intro{display:flex;align-items:center;justify-content:space-between;gap:40px;padding-top:25px}
.physics-chrome .focus-intro h2{font-size:clamp(35px,4.9vw,77px);letter-spacing:-.065em;line-height:.93;max-width:60%}
.physics-chrome .focus-intro .formula{font-size:clamp(23px,2.8vw,44px);height:auto;min-height:70px;flex-shrink:0;display:flex;flex-direction:column;justify-content:center;gap:8px}
.physics-chrome .focus-stage{flex:1;min-height:300px;height:calc(100dvh - 300px);cursor:grab;touch-action:none}
.physics-chrome .focus-foot{display:flex;align-items:center;justify-content:space-between;gap:20px;border-top:1px solid var(--line);padding:10px 0}
.physics-chrome .focus-foot button{font:10px var(--mono);min-height:42px;padding:0}
.physics-chrome .focus-foot p{font-size:17px;letter-spacing:-.03em;text-align:center}
.physics-chrome .focus-hint{text-align:center;font:8px var(--mono);color:var(--muted);padding:0 0 15px}
.physics-chrome .gpu-fallback{position:absolute;inset:35% 10%;font-size:14px;line-height:1.5}
.physics-chrome .gpu-fallback a{text-decoration:underline}
.physics-chrome .noscript{padding:30px}
.physics-chrome dialog[data-scene=fluid] .focus-intro .formula{font-size:clamp(17px,2.45vw,37px)}
@media(min-width:1760px){.physics-chrome .masthead h1{font-size:123px}
}
@media(max-width:1050px){.physics-chrome .equations{gap:32px 23px}
.physics-chrome .chrome-console{gap:3vw;margin-bottom:35px}
.physics-chrome h2{font-size:1.84vw}
.physics-chrome .card-heading{gap:7px;min-height:30px}
.physics-chrome .caption{font-size:14px}
.physics-chrome .formula{height:70px}
.physics-chrome .object-index{font-size:8px}
.physics-chrome .edition{margin-left:20px}
.physics-chrome .site-register{padding-top:19px;padding-bottom:18px}
.physics-chrome .wordmark{font-size:29px}
}
@media(max-width:800px){.physics-chrome .equations{grid-template-columns:repeat(2,minmax(0,1fr));gap:36px 25px}
.physics-chrome .card-heading h2{font-size:23px}
.physics-chrome .study-register{margin-bottom:32px}
.physics-chrome .masthead h1{font-size:7.1vw}
.physics-chrome .hero-bottom{padding:24px 0}
.physics-chrome .hero-bottom p{font-size:17px}
.physics-chrome .chrome-console{grid-template-columns:.65fr repeat(3,minmax(0,1.3fr));gap:20px}
.physics-chrome .reset-objects{display:none}
.physics-chrome .formula{height:77px}
.physics-chrome .caption{font-size:17px}
.physics-chrome .edition{display:none}
.physics-chrome .site-section{font-size:9px}
.physics-chrome .wordmark{font-size:28px}
.physics-chrome .focus-intro{gap:20px}
.physics-chrome .focus-intro h2{font-size:40px}
.physics-chrome .focus-intro .formula{font-size:25px}
.physics-chrome .focus-stage{height:calc(100dvh - 305px)}
}
@media(max-width:520px){.physics-chrome .site-register{padding-top:19px;padding-bottom:17px}
.physics-chrome .wordmark{font-size:26px}
.physics-chrome .site-section{font-size:8px;max-width:128px;text-align:right;line-height:1.4}
.physics-chrome .site-section span{padding:0 5px}
.physics-chrome .study-register{margin:21px 0 26px;font-size:8px}
.physics-chrome .masthead h1{font-size:9.7vw;line-height:.94;white-space:normal;max-width:355px;letter-spacing:-.073em}
.physics-chrome .hero-bottom{padding:19px 0 23px}
.physics-chrome .hero-bottom p{font-size:15px}
.physics-chrome .hero-bottom>span{font-size:8px}
.physics-chrome .hero-bottom>span span{margin-left:8px;font-size:18px}
.physics-chrome .chrome-console{gap:12px 24px;grid-template-columns:repeat(2,minmax(0,1fr));padding:14px 0 10px;margin-bottom:30px}
.physics-chrome #chrome-play{font-size:14px;gap:8px}
.physics-chrome .range-control{font-size:8px}
.physics-chrome .range-control>span{gap:5px}
.physics-chrome .equations{grid-template-columns:1fr;gap:28px}
.physics-chrome .card-heading h2{font-size:25px}
.physics-chrome .card-heading{min-height:36px}
.physics-chrome .object-index{font-size:9px;padding-top:5px}
.physics-chrome .card-heading abbr{font-size:10px}
.physics-chrome .formula{height:79px;font-size:7.6cqw}
.physics-chrome .formula-fluid{font-size:5.4cqw}
.physics-chrome .formula-einstein{font-size:7.2cqw}
.physics-chrome .object-stage{aspect-ratio:1.4}
.physics-chrome .caption{font-size:18px;min-height:30px;margin-top:5px}
.physics-chrome .caption small{font-size:12px}
.physics-chrome .study-footer{margin-top:35px;padding-top:25px}
.physics-chrome .closing{font-size:34px;max-width:340px}
.physics-chrome .footer-register{font-size:8px;padding:20px 0;gap:12px}
.physics-chrome .footer-register span:last-child{white-space:nowrap}
.physics-chrome .source-note{align-items:flex-start;font-size:9px;gap:18px}
.physics-chrome .source-note p{max-width:240px}
.physics-chrome .focus-header{font-size:9px}
.physics-chrome .focus-intro{display:block;padding-top:22px}
.physics-chrome .focus-intro h2{font-size:38px;max-width:none}
.physics-chrome .focus-intro .formula{align-items:flex-start;margin-top:10px;font-size:27px;min-height:65px}
.physics-chrome .focus-stage{height:calc(100dvh - 340px);min-height:260px}
.physics-chrome .focus-foot{gap:10px}
.physics-chrome .focus-foot p{font-size:14px;max-width:180px}
.physics-chrome .focus-foot button{font-size:8px}
.physics-chrome .focus-hint{font-size:7px;line-height:1.7}
}
@media(max-width:520px){.physics-chrome dialog[data-scene=fluid] .focus-intro .formula{font-size:4.4vw}
}
@media(prefers-reduced-motion:reduce){.physics-chrome *,.physics-chrome *::before,.physics-chrome *::after{transition:none!important;scroll-behavior:auto!important}
}

.physics-chrome .page-body{padding:0;max-width:none}
.physics-chrome .study-register{margin-top:35px}
.physics-chrome .physics-still{display:block;width:100%;height:100%;object-fit:contain;pointer-events:none}
.physics-chrome[data-renderer=webgl] .physics-still{visibility:hidden}
.physics-chrome button:disabled,.physics-chrome input:disabled{opacity:.4;cursor:default}
.physics-chrome .source-note{justify-content:flex-start}

.physics-chrome[data-renderer=static] .object-stage{cursor:default}

.observer-study{position:relative;z-index:1;max-width:1760px;margin:0 auto clamp(48px,8vw,120px);padding:0 var(--gutter)}
.observer-study observer-effect{display:block;position:relative;width:100%;aspect-ratio:16/9;background:#080909}
.observer-study observer-effect[data-compact]{aspect-ratio:640/820}
.observer-study>observer-effect>img{display:block;position:absolute;inset:0;width:100%;height:100%;object-fit:contain}