@font-face{font-family:AtlasSans;src:local('Avenir Next'),local('Avenir'),local('Helvetica Neue');font-display:swap}
:root{--paper:#f3efe6;--ink:#203d38;--muted:#65736b;--line:#d9dacf;--teal:#173f38;--gold:#b38b49;--copper:#ae6344;--serif:Georgia,'Times New Roman',serif;--sans:AtlasSans,Arial,sans-serif;color-scheme:light}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:20px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);-webkit-font-smoothing:antialiased}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button{color:inherit}button:disabled{cursor:default}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,.stage:focus-visible{outline:3px solid #bc7751;outline-offset:4px}button{border:0}a{color:inherit}svg{fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}button[hidden],svg[hidden],[hidden]{display:none!important}.skip-link{position:absolute;top:-100px;left:20px;background:var(--teal);color:white;padding:15px;z-index:50}.skip-link:focus{top:10px}.site-header{max-width:1440px;margin:auto;height:91px;padding:0 64px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:13px;text-decoration:none;font-size:23px;font-weight:600;letter-spacing:-.7px}.brand svg{width:37px;height:37px;stroke:var(--teal);stroke-width:1.25}.brand-core{fill:var(--gold);stroke:none}.brand-light{font-weight:400}.atlas-label{font-size:9px;letter-spacing:2.2px;color:var(--muted)}.atlas-label span{margin-left:20px;color:var(--gold)}.text-button{background:none;font-size:12px;letter-spacing:.2px;padding:12px 0}.text-button span{padding-left:14px;font-size:18px}main{max-width:1440px;margin:auto;padding:0 64px}.intro{display:flex;justify-content:space-between;align-items:flex-end;padding:45px 0 30px;gap:40px}.eyebrow{font-size:9px;letter-spacing:1.8px;font-weight:600;display:flex;gap:12px;align-items:center;margin:0 0 16px}.tiny-line{width:23px;height:1px;background:var(--gold)}h1{font:normal 58px/1.035 var(--serif);letter-spacing:-2.4px;margin:0}h1 em{font-weight:400;color:#7c866f}.intro-copy{max-width:292px;padding-bottom:5px}.intro-copy p{font-size:13px;line-height:1.75;color:var(--muted);margin:0 0 13px}.intro-link{font-size:11px;font-weight:600;text-decoration:none;display:flex;align-items:center;gap:25px}.intro-link span{font-size:19px;color:var(--gold)}.explorer{display:grid;grid-template-columns:minmax(0,1fr) 321px;gap:34px;align-items:start}.model-area{min-width:0}.model-topbar{display:flex;justify-content:space-between;align-items:center;height:50px;position:relative;z-index:2}.segmented{display:flex;border:1px solid #d3d6ca;background:#eae9df80;border-radius:25px;padding:4px;gap:3px}.segmented button{font-size:10px;padding:8px 15px;border-radius:20px;background:transparent;color:#68766b;transition:background .2s}.segmented button[aria-pressed=true]{background:#fffaf1;color:var(--ink);box-shadow:0 1px 4px #273d3311}.icon-button{display:grid;place-items:center;border:1px solid #d3d6ca;background:transparent;border-radius:50%;width:36px;height:36px;font-size:25px}.icon-button svg{height:17px;width:17px}.stage{position:relative;width:100%;height:480px;isolation:isolate;touch-action:none;border-radius:18px;overflow:hidden;outline-offset:-4px!important}.stage canvas{display:block;position:absolute;inset:0;z-index:1;touch-action:none}.stage-ambient{position:absolute;inset:15% 0 0;background:radial-gradient(ellipse at 49% 51%,#dfdcc944 0,#e3dfcd22 39%,transparent 66%);pointer-events:none}.stage-ambient:after{content:'';position:absolute;width:60%;height:10%;bottom:10%;left:20%;background:radial-gradient(ellipse,#52635416,transparent 65%);filter:blur(15px)}.loading{position:absolute;inset:0;display:flex;gap:20px;align-items:center;justify-content:center;font-size:12px;z-index:8;background:var(--paper);flex-direction:column;color:var(--muted)}.loading-ring{width:32px;height:32px;border:1px solid #bca568;border-top-color:transparent;border-radius:50%;animation:spin 2s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.compartment{position:absolute;left:2px;font-size:8px;letter-spacing:1.6px;z-index:3;pointer-events:none;color:#67796d}.compartment span{display:block;font-size:9px;letter-spacing:0;margin-top:6px;color:#829083}.matrix{top:38px}.ims{bottom:39px}.hotspot{position:absolute;top:0;left:0;z-index:4;background:#f6f3ebed;backdrop-filter:blur(8px);border:1px solid #d7d8ca88;box-shadow:0 2px 6px #243c3410;display:flex;align-items:center;gap:10px;padding:8px 12px;border-radius:5px;font-size:10px;text-align:left;white-space:nowrap;opacity:0;transition:opacity .3s,background .2s;will-change:transform}.hotspot small{display:block;color:#788377;font-size:8px;margin-top:4px}.hotspot-dot{height:5px;width:5px;border-radius:50%;background:var(--gold);box-shadow:0 0 0 3px #c3a25d20}.hotspot[data-part=rotor] .hotspot-dot{background:var(--copper)}.hotspot[data-part=stator] .hotspot-dot{background:#66766b}.proton-hotspot .hotspot-dot{background:#a28321;box-shadow:0 0 0 3px #b3953033}.hotspot:hover,.hotspot[aria-pressed=true]{background:#fffaf1;border-color:#b5b9a4}.stage-caption{position:absolute;bottom:6px;left:0;right:0;text-align:center;font-size:8px;color:#899384;z-index:3;letter-spacing:.3px;pointer-events:none}.model-bottom{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:16px 0;display:flex;justify-content:space-between;align-items:center;gap:18px}.playback{display:flex;align-items:center;gap:13px}.play-button{width:40px;height:40px;border-radius:50%;display:grid;place-items:center;background:var(--teal);color:#f4eacb;flex-shrink:0}.play-button svg{width:19px;height:19px;stroke-width:2}.play-button #play-icon{fill:currentColor;stroke:none;width:15px}.playback-copy{display:flex;flex-direction:column;gap:5px}.playback-copy strong{font-size:11px;font-weight:500}.playback-copy span{font-size:8px;color:var(--muted)}.speed-control{display:flex;align-items:center;gap:11px;font-size:9px;color:var(--muted)}.speed-control input{width:80px;height:3px;accent-color:var(--teal)}.speed-control output{min-width:26px;font-size:10px;color:var(--ink);font-variant-numeric:tabular-nums}.model-options{display:flex;align-items:center;gap:20px;min-height:46px;color:var(--muted);font-size:9px}.gesture-hint{display:flex;gap:7px;align-items:center;flex:1}.gesture-hint svg{height:17px;width:17px}.model-options label{display:flex;gap:5px;align-items:center;font-size:9px}.model-options input{accent-color:var(--teal);width:12px;height:12px}.zoom-buttons{display:flex;gap:4px}.zoom-buttons button{background:#e6e7dc;border-radius:50%;width:26px;height:26px;font-size:17px}.snapshot-controls{display:flex;align-items:center;gap:10px;flex-wrap:wrap;color:var(--muted);font-size:9px;padding:5px 0 0}.snapshot-controls select{border:1px solid #c7cebe;background:transparent;color:var(--ink);border-radius:4px;padding:6px 22px 6px 7px;font-size:9px}.snapshot-controls>span{margin-left:auto;color:#7f897c;font-size:8px}.lesson-panel{background:var(--teal);color:#e9ecdf;border-radius:11px;padding:27px 26px 23px;box-shadow:0 15px 45px #1c3e3012;margin-top:4px}.lesson-top{display:flex;justify-content:space-between;align-items:center}.lesson-top .eyebrow{font-size:8px;letter-spacing:1.7px;color:#adbda7;margin:0}.lesson-top>span:last-child{font-size:9px;color:#bcc5ae;font-variant-numeric:tabular-nums}.step-track{display:flex;gap:5px;margin:16px 0 29px}.step-track button{height:3px;border-radius:1px;background:#ffffff26;flex:1;padding:0;position:relative}.step-track button:after{content:'';position:absolute;inset:-8px 0}.step-track button[aria-pressed=true]{background:#d5b56e}.story-kicker{font-size:8px;letter-spacing:1.5px;color:#d0b376;margin:0 0 13px}h2{font:normal 32px/1.12 var(--serif);letter-spacing:-.6px;margin:0 0 16px}#story-description{font-size:11px;line-height:1.85;color:#b8cbbb;min-height:102px;margin:0}.energy-diagram{display:flex;align-items:center;justify-content:space-between;margin:22px 0 25px;padding:18px 0;border-top:1px solid #cbd3b821;border-bottom:1px solid #cbd3b821}.energy-diagram>span{font:normal 20px var(--serif);text-align:center;color:#e2c991}.energy-diagram small{display:block;font:normal 6px var(--sans);letter-spacing:1px;color:#a1b49e;margin-top:8px}.energy-diagram svg{width:22px;height:22px;vertical-align:middle}.energy-diagram b{font:normal 15px var(--sans);color:#758f7c;margin-top:-15px}.story-navigation{display:flex;gap:10px;align-items:center}.story-navigation button{border:1px solid #dae1c62e;background:transparent;height:36px;border-radius:4px;color:#e2e5ce}.story-navigation #story-prev{width:36px;font-size:16px;flex-shrink:0}.story-navigation #story-prev:disabled{opacity:.3}.story-navigation #story-next{font-size:10px;flex:1;padding:0 13px;display:flex;align-items:center;justify-content:space-between;background:#d1ba7a;color:#193e36;border-color:#d1ba7a}.story-navigation #story-next span{font-size:16px}.panel-divider{height:1px;background:#cbd3b821;margin:27px 0 22px}.parts-heading{font-size:8px;color:#b9c8af;letter-spacing:1.1px;margin:0 0 12px;display:flex;justify-content:space-between}.parts-heading span{font-size:8px;color:#91a68b;letter-spacing:0}.parts{display:grid;grid-template-columns:1fr 1fr;gap:7px}.parts button{background:#12382f;color:#c4d3bf;border:1px solid #8eaa8027;border-radius:4px;text-align:left;font-size:9px;height:32px;padding:0 9px;display:flex;align-items:center;gap:7px}.parts button[aria-pressed=true]{border-color:#d4b575;background:#d7c69115;color:#f2e9c8}.swatch{width:5px;height:5px;border-radius:50%;background:#d3b373;flex-shrink:0}.head-swatch{background:#bdac64}.rotor-swatch{background:#dc906d}.stator-swatch{background:#94aaa0}.proton-swatch{background:#e8c557}.part-detail{margin-top:18px}.part-detail strong{font-size:11px;font-weight:500;color:#e2e6ce}.part-detail p{font-size:10px;line-height:1.8;color:#a8bea8;margin:8px 0 12px;min-height:54px}.part-detail>span{font-size:6.5px;letter-spacing:1px;color:#86a089;display:block;line-height:1.6}.show-all{background:none;padding:10px 0 0;color:#d4bf82;font-size:9px}.insight-strip{display:grid;grid-template-columns:1fr 1fr 1fr;border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin:35px 0 0}.insight-strip button{display:flex;align-items:center;text-align:left;gap:18px;background:transparent;padding:23px 24px 23px 0;position:relative}.insight-strip button+button{border-left:1px solid var(--line);padding-left:25px}.fact-number{font:normal 44px var(--serif);letter-spacing:-1px;color:#667459;white-space:nowrap}.fact-number>span{font-size:25px;vertical-align:top}.fact-copy{display:flex;flex-direction:column;gap:7px}.fact-copy strong{font-size:10px;font-weight:500}.fact-copy small{font-size:8px;line-height:1.6;color:#7a8478;max-width:170px}.fact-arrow{font-size:14px;color:#a6ad95;margin-left:auto}footer{display:flex;justify-content:space-between;align-items:center;padding:27px 0 34px;gap:20px}footer>p{font:italic 15px var(--serif);color:#8a927f;margin:0}footer>div{display:flex;align-items:center;gap:25px;font-size:8px;color:#8b9585}footer button{background:none;color:#657462;font-size:8px;padding:9px 0}footer button span{font-size:12px;padding-left:8px}dialog{width:min(670px,calc(100% - 32px));max-height:85vh;padding:30px 34px;border:1px solid var(--line);border-radius:12px;background:var(--paper);color:var(--ink);box-shadow:0 30px 120px #071d3060}dialog::backdrop{background:#153b3466;backdrop-filter:blur(5px)}.dialog-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:26px}.dialog-top .eyebrow{font-size:8px;margin:0}dialog h2{font-size:34px}dialog h2 em{color:#7c866f;font-weight:400}dialog p{font-size:12px;line-height:1.8;color:#61715f}dialog h3{font-size:11px;margin-top:24px}dialog a{text-underline-offset:3px}dialog .source-small{font-size:9px;color:#82917d;margin-top:25px}.noscript{padding:30px;background:#e3e2d3;text-align:center;font-size:14px}.webgl-fallback{padding:25px!important;line-height:1.8;text-align:center}.webgl-fallback a{display:block}.selected-outline{border-color:#cdb875!important}
@media(min-width:1500px){.stage{height:540px}.intro{padding-top:52px}.lesson-panel{padding-top:30px}}
@media(max-width:1100px){.site-header{padding:0 35px}main{padding:0 35px}.explorer{gap:22px;grid-template-columns:minmax(0,1fr) 295px}.lesson-panel{padding:24px 23px}.stage{height:510px}.hotspot{font-size:9px;padding:7px 9px;gap:8px}.hotspot small{font-size:7px}.model-bottom{align-items:flex-start;flex-direction:column;gap:14px}.speed-control{margin-left:53px}.fact-number{font-size:38px}.insight-strip button{gap:12px}.insight-strip button+button{padding-left:18px}.fact-copy small{font-size:8px}}
@media(max-width:780px){.site-header{height:75px;padding:0 24px}.atlas-label{display:none}main{padding:0 24px}.brand{font-size:21px}.brand svg{width:31px}.intro{padding:30px 0 23px;gap:25px}h1{font-size:47px;letter-spacing:-1.9px}.intro-copy{max-width:235px}.intro-copy p{font-size:12px}.explorer{grid-template-columns:1fr;gap:25px}.stage{height:490px}.model-bottom{flex-direction:row;align-items:center}.speed-control{margin:0}.lesson-panel{padding:27px;display:grid;grid-template-columns:1fr 1fr;column-gap:25px}.lesson-top,.step-track{grid-column:1/-1}.step-track{margin-bottom:22px}#story-content{grid-column:1}#story-description{min-height:0}.energy-diagram{grid-column:1;margin-bottom:14px}.story-navigation{grid-column:1}.panel-divider{display:none}.parts-heading{grid-column:2;grid-row:3;align-self:start;margin-top:4px}.parts{grid-column:2;grid-row:3;align-self:start;margin-top:29px}.part-detail{grid-column:2;grid-row:4/6;align-self:start;margin-top:0}.show-all{grid-column:2}.insight-strip{margin-top:27px}.insight-strip button{flex-wrap:wrap;gap:10px}.fact-copy{width:100%}.fact-copy small{max-width:160px}.fact-arrow{position:absolute;right:17px;top:32px}footer>div{gap:12px}footer>p{font-size:13px}.compartment{left:5px}}
@media(max-width:520px){.site-header{padding:0 20px;height:70px}main{padding:0 20px}.text-button{font-size:10px}.intro{display:block;padding-top:27px}.eyebrow{font-size:8px;letter-spacing:1.5px;margin-bottom:14px}h1{font-size:48px}.intro-copy{max-width:100%;margin-top:20px;display:flex;align-items:center;gap:15px}.intro-copy p{font-size:11px;line-height:1.7;margin:0;max-width:280px}.intro-link{display:none}.stage{height:410px;margin-top:4px;margin-left:-9px;width:calc(100% + 18px)}.model-topbar{height:45px}.segmented button{padding:8px 12px;font-size:9px}.icon-button{height:33px;width:33px}.compartment{font-size:6px;letter-spacing:1px}.compartment span{font-size:7px;margin-top:4px}.matrix{top:24px}.ims{bottom:22px}.stage-caption{font-size:6.5px;bottom:2px}.hotspot{padding:6px 7px;font-size:8px;gap:7px;border-radius:4px}.hotspot small{font-size:6.5px}.hotspot-dot{width:4px;height:4px}.model-bottom{padding:14px 0;gap:10px}.playback{gap:9px}.play-button{width:34px;height:34px}.playback-copy strong{font-size:9px}.playback-copy span{font-size:6.5px;max-width:135px;line-height:1.5}.speed-control{gap:7px;font-size:8px}.speed-control input{width:50px}.speed-control output{font-size:9px;min-width:23px}.model-options{font-size:8px;gap:11px;min-height:42px}.gesture-hint{font-size:7px;gap:4px}.gesture-hint svg{width:14px}.model-options label{font-size:8px;gap:3px}.model-options input{width:11px}.zoom-buttons button{width:24px;height:24px}.snapshot-controls{font-size:8px;gap:8px;padding-top:0}.snapshot-controls select{font-size:8px;max-width:150px}.snapshot-controls>span{display:none}.explorer{gap:26px}.lesson-panel{display:block;padding:25px 24px;border-radius:9px}.lesson-top .eyebrow{font-size:7px}.step-track{margin:16px 0 23px}h2{font-size:31px}#story-description{font-size:11px;min-height:0}.energy-diagram{margin:20px 0}.energy-diagram small{font-size:6.5px}.energy-diagram>span{font-size:24px}.story-navigation #story-next{font-size:10px}.panel-divider{display:block;margin:25px 0 20px}.parts-heading{margin:0 0 13px}.parts{margin:0}.parts button{font-size:10px;height:36px}.part-detail{margin:18px 0 0}.part-detail strong{font-size:12px}.part-detail p{font-size:11px;min-height:0}.part-detail>span{font-size:7px}.insight-strip{grid-template-columns:1fr;margin-top:28px}.insight-strip button{flex-wrap:nowrap;padding:18px 0;gap:24px;min-height:95px}.insight-strip button+button{border-left:none;border-top:1px solid var(--line);padding-left:0}.fact-copy{width:auto}.fact-number{font-size:42px;width:76px;flex-shrink:0}.fact-copy strong{font-size:11px}.fact-copy small{font-size:9px;max-width:180px}.fact-arrow{position:static;margin-left:auto}footer{display:block;padding:24px 0 25px}footer>p{font-size:15px;margin-bottom:11px}footer>div{justify-content:space-between;font-size:7px}footer button{font-size:7px}dialog{padding:22px}dialog h2{font-size:29px}dialog p{font-size:11px}.dialog-top .eyebrow{font-size:6.5px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}}
.reduce-motion-option{display:flex;align-items:center;gap:5px;font-size:8px;color:var(--muted);margin-top:12px}.reduce-motion-option input{width:12px;height:12px;accent-color:var(--teal)}.reduce-motion{scroll-behavior:auto}.reduce-motion *,.reduce-motion *:before,.reduce-motion *:after{animation:none!important;transition:none!important}
.focus-controls{display:flex;align-items:center;gap:5px;padding:5px 0 8px;color:var(--muted)}.focus-controls>span{font-size:6.5px;letter-spacing:1.1px;margin-right:7px}.focus-controls button{background:none;border:1px solid transparent;border-radius:13px;padding:6px 9px;font-size:8px;color:#6a7b6e}.focus-controls button[aria-pressed=true]{border-color:#becbbb;color:var(--ink);background:#e2e8db55}.bilayer-hotspot .hotspot-dot{background:#71947b}.bilayer-part{grid-column:1/-1}.bilayer-part>span{margin-left:auto;font-size:7px;color:#819e87}.bilayer-swatch{background:#a4bca4}.part-actions{display:flex;justify-content:space-between;gap:12px}.channel-label{position:absolute;z-index:4;color:#987326;font-size:9px;background:#fff4d6ee;padding:6px 8px;border-radius:5px;pointer-events:none;max-width:140px}.channel-label small{display:block;font-size:6.5px;color:#9c8b5c;margin-top:4px}.stage-caption{color:#627364;background:#f3efe6bf;border-radius:4px;left:15%;right:15%;padding:3px}.head-swatch{background:#73979f}.reduce-motion-option{margin-top:11px}
@media(max-width:520px){.focus-controls{gap:2px;padding-top:2px}.focus-controls>span{font-size:5.5px;margin-right:4px}.focus-controls button{font-size:7px;padding:5px 7px}.channel-label{font-size:7px;max-width:100px;padding:4px 6px}.channel-label small{font-size:5px}.bilayer-part>span{font-size:7px}.stage-caption{left:8%;right:8%;font-size:6px}}
.compartment{background:#f3efe6df;border-radius:4px;padding:6px 7px;max-width:150px;line-height:1.3}.compartment span{line-height:1.4}.stage{background:radial-gradient(ellipse at 50% 52%,#e4ddcf50,transparent 70%)}
.catalytic-cycle{margin:19px 0 0;border:1px solid #c9bc812b;border-radius:5px;padding:12px 10px}.cycle-heading{font-size:6.5px;letter-spacing:1px;color:#aab995}.cycle-sites{display:flex;justify-content:space-between;gap:8px;margin-top:13px}.cycle-sites>span{flex:1;text-align:center;color:#9db59e;padding:6px 2px;border-radius:3px;transition:background .3s}.cycle-sites strong{font-family:var(--serif);font-size:17px;font-weight:400}.cycle-sites small{display:block;font-size:7px;line-height:1.4;margin-top:6px;white-space:nowrap}.cycle-sites .is-making{background:#cab57923;color:#e3c88d}
@media(max-width:780px) and (min-width:521px){.catalytic-cycle{grid-column:1}.lesson-panel:has(.catalytic-cycle:not([hidden])) .part-detail{grid-row:4/7}}