:root{font-family:Inter,"Segoe UI",Arial,sans-serif;color:#203a35;background:#f3f5f0;font-synthesis:none;--green:#17644c;--ink:#163f36;--muted:#64756f;--border:#dce3dd;--paper:#fff;--accent:#a8e4bd;--orange:#ffb779;--blue:#85c8ee;--purple:#c3acf3}*{box-sizing:border-box}body{margin:0}button,select,input{font:inherit}button,select{cursor:pointer}button{border:1px solid var(--border);background:#fff;color:var(--ink);border-radius:7px;padding:8px 11px;font-size:13px;font-weight:600;min-height:35px;transition:background .12s,border-color .12s}button:hover{background:#f0f5ef;border-color:#a3b6aa}button:disabled{opacity:.45;cursor:default}button:focus-visible,select:focus-visible,input:focus-visible,[tabindex]:focus-visible{outline:3px solid #de9c23;outline-offset:3px}button[aria-pressed=true]{background:#e4f2e8;border-color:#8bbba0;color:#145b3e}select,input[type=number]{border:1px solid #cdd9d0;border-radius:6px;background:#fff;color:#203a35;min-height:35px;padding:7px 9px;max-width:100%;font-size:13px}input[type=range]{accent-color:var(--green);width:100%;margin:9px 0 2px}input[type=checkbox]{accent-color:var(--green)}[hidden]{display:none!important}.skip-link{position:fixed;left:12px;top:-70px;z-index:30;padding:12px;background:white}.skip-link:focus{top:10px}.topbar{min-height:70px;background:#fff;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:12px 24px;gap:16px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:#173c32}.brand-mark{font-size:27px;font-weight:800;letter-spacing:-3px;background:#e5f0e1;padding:3px 9px 5px;border-radius:10px}.brand-mark span{color:#57995b;font-size:22px}.brand-name{font-size:18px;font-weight:750;letter-spacing:-.5px}.brand-name small{display:block;font-size:8px;letter-spacing:1.4px;font-weight:600;margin-top:3px}.top-actions{display:flex;align-items:center;gap:9px}.course-label{display:flex;align-items:center;gap:9px;color:var(--muted);font-size:12px}.course-label select{border:0;background:#f2f5ef}.app-shell{display:grid;grid-template-columns:192px minmax(0,1fr);min-height:calc(100vh - 71px)}.navigation{border-right:1px solid var(--border);padding:26px 14px 16px;background:#edf2e9;display:flex;flex-direction:column}.eyebrow{font-size:9px;font-weight:750;letter-spacing:1.6px;color:#65796c;display:block;line-height:1.5;margin:0 0 7px}.lab-title{padding:0 10px 23px}.lab-title h1{font-size:19px;letter-spacing:-.6px;line-height:1.25;margin:0;font-weight:650}#workspaces{display:flex;flex-direction:column;gap:5px}#workspaces button{text-align:left;border:0;border-radius:8px;background:transparent;padding:12px 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18px;min-width:0;max-width:1700px;width:100%;margin:auto}.experiment-heading{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:19px}h2{font-size:28px;letter-spacing:-.8px;font-weight:650;margin:0;line-height:1.1}.experiment-select{display:flex;flex-direction:column;gap:5px;min-width:205px;max-width:300px}.experiment-select label{font-size:10px;color:var(--muted);font-weight:600}.experiment-select select{background:#fff;font-size:12px}.workspace-grid{display:grid;grid-template-columns:minmax(0,1fr) 246px;gap:18px;align-items:start}.bench{background:#fff;border:1px solid var(--border);border-radius:12px;overflow:hidden;min-width:0;box-shadow:0 4px 14px #143e2905}.stage-top{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:12px 17px;font-size:11px;font-weight:600;color:#4c6359}.stage-top>div{display:flex;align-items:center;gap:10px}.stage-top button{font-size:10px;padding:5px 9px;min-height:28px}.state-dot{font-weight:400;color:#60756a;max-width:175px}.state-dot:before{content:"";display:inline-block;width:5px;height:5px;border-radius:50%;background:#7baa81;margin-right:6px}.stage{background:#102921;position:relative;aspect-ratio:1.62;min-height:280px;isolation:isolate;overflow:hidden;touch-action:pan-y}.stage>svg{display:block;width:100%;height:100%;position:absolute;inset:0}.stage svg text{font-family:Inter,"Segoe UI",sans-serif;fill:#dbe8df}.stage svg .muted{fill:#8eaaa0}.stage svg .axis-label{font-size:13px;fill:#b4cabd}.stage svg .diagram-label{font-size:15px}.stage svg .minor-label{font-size:12px}.stage svg .handle{cursor:grab;touch-action:none}.stage svg .handle:active{cursor:grabbing}.stage svg .hit-track{cursor:pointer;stroke:transparent;stroke-width:18;fill:none}.stage svg .hit-track:focus-visible{stroke:#ffffff35;outline:none}.stage svg .selectable{cursor:pointer}.stage-tools{display:flex;align-items:center;justify-content:center;gap:8px;padding:10px 12px;background:#f7f9f5;min-height:51px;flex-wrap:wrap}.stage-tools button{font-size:11px;padding:6px 10px;min-height:30px}.stage-tools .particle-add{border-color:#bbd3c1}.stage-tools .inline-label{font-size:11px;color:#66796d}.transport{display:flex;align-items:center;gap:7px;padding:13px 15px;border-top:1px solid #e7ece6;flex-wrap:wrap}.transport button{font-size:11px;padding:7px 10px}.primary{background:#24553f;color:#fff;border-color:#24553f}.primary:hover{background:#18452f;color:white}.clock{font-variant-numeric:tabular-nums;margin-left:auto;font-size:13px;font-weight:600;color:#335946}.time-note{font-size:9px;color:#7c8e82;flex-basis:100%;text-align:right;margin-top:-2px}.readings{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));margin:0 15px 10px;border-top:1px solid #e6ece5;padding-top:13px;gap:16px}.reading-label{color:#718277;font-size:10px;display:block;margin-bottom:5px}.reading-value{font-size:23px;font-weight:600;color:#234f3e;font-variant-numeric:tabular-nums;letter-spacing:-.5px;overflow-wrap:anywhere}.reading-value small{font-size:11px;font-weight:400;margin-left:4px;letter-spacing:0}.reading-detail{display:block;font-size:9px;color:#7b887e;line-height:1.5;margin-top:3px}.bench-caption{padding:0 15px 12px;font-size:10px;line-height:1.5;color:#78897e}.inspector{padding:8px 0;min-width:0}.inspector-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:15px}.inspector-heading .eyebrow{margin:0}.switch{font-size:11px;color:#6b7b6c;display:flex;align-items:center;gap:5px}.task{border-left:3px solid #7ca17b;padding:0 0 0 12px;margin:0 0 22px}.task h3{font-size:14px;line-height:1.45;letter-spacing:-.2px;margin:0 0 6px;font-weight:650}.task p{font-size:11px;line-height:1.65;color:#6b7d70;margin:0}.task ol{padding-left:16px;font-size:11px;line-height:1.7;color:#5e7366;margin-bottom:0}.control-group{border-top:1px solid var(--border);padding:15px 0 0;margin-top:15px}.control-group:first-child{border:0;padding-top:0;margin-top:0}.control-group h3{font-size:10px;color:#4f6d59;font-weight:700;letter-spacing:.7px;text-transform:uppercase;margin:0 0 12px}.field{display:block;margin-bottom:15px}.field-heading{display:flex;justify-content:space-between;align-items:center;font-size:11px;color:#526d5c;gap:8px;margin-bottom:6px}.field-heading output{font-weight:650;color:#284d37;font-variant-numeric:tabular-nums}.field>select{width:100%;font-size:12px}.number-range{display:flex;gap:10px;align-items:center}.number-range input[type=number]{width:75px;font-size:12px}.number-range input[type=range]{flex:1;min-width:0}.control-help{font-size:10px;color:#7b897b;line-height:1.6;margin:6px 0 12px}.button-row{display:flex;gap:5px;flex-wrap:wrap}.button-row button{font-size:11px;min-height:31px;padding:5px 8px}.wide-button{width:100%;margin:5px 0;font-size:11px}.selected-track{padding:10px 12px;border:1px solid #d6e1d5;border-radius:7px;background:#f8faf5;font-size:11px;line-height:1.65;color:#4c6959;margin:10px 0}.selected-track strong{color:#234b36}.model-info{margin-top:20px;border-top:1px solid var(--border);padding-top:13px;font-size:10px;line-height:1.7;color:#6d7e70}.model-info summary{cursor:pointer;font-weight:600;color:#4c6859}.model-info p{margin:9px 0}.model-info a{color:#347959}.notebook{margin-top:16px;border:1px solid var(--border);border-radius:10px;background:#fff;overflow:hidden}.notebook-bar{padding:9px 12px;display:flex;align-items:center;gap:7px;flex-wrap:wrap}.notebook-bar button{font-size:11px;min-height:32px}.notebook-bar .capture{color:#225a3d;background:#eaf3e5;border-color:#d5e4cb}.notebook-bar #notebook-toggle{border-color:transparent}.notebook-bar #capture-count{background:#eaf0e8;border-radius:4px;padding:1px 5px;font-size:10px;margin-left:3px}.notebook-actions{margin-left:auto;display:flex;gap:7px}.notebook-actions button{border-color:transparent;font-weight:500}.evidence-toolbar{display:flex;align-items:center;gap:12px;flex-wrap:wrap;padding:12px;border-top:1px solid var(--border);font-size:11px}.evidence-toolbar label{display:flex;align-items:center;gap:8px;color:#718071}.evidence-toolbar select{font-size:11px;min-height:29px}.segmented{display:flex;gap:3px}.segmented button{font-size:11px;min-height:30px}.evidence-toolbar>button{margin-left:auto;font-size:10px;border:0}.graph{min-height:235px;padding:5px 12px 12px}.graph svg{display:block;width:100%;height:240px}.graph-empty{padding:50px 20px;text-align:center;color:#7b897d;font-size:12px;line-height:1.8}.table-wrap{overflow:auto;max-height:330px;padding:0 14px 12px}.table-wrap table{border-collapse:collapse;width:100%;font-size:11px}.table-wrap th,.table-wrap td{text-align:left;border-bottom:1px solid #e5ebe2;padding:10px 9px;white-space:nowrap}.table-wrap th{font-size:10px;color:#71816f}.table-wrap button{font-size:10px;min-height:24px;padding:3px 6px}.kept-runs{display:flex;gap:8px;padding:0 15px 12px;flex-wrap:wrap;font-size:10px;color:#637465}.kept-runs button{font-size:10px;padding:4px 7px;min-height:25px}.course-note{font-size:10px;line-height:1.6;color:#7f8d7e;margin:14px 0 0}.toast{position:fixed;bottom:20px;left:50%;transform:translateX(-50%);max-width:calc(100% - 28px);padding:12px 18px;background:#1f4839;color:#fff;border-radius:8px;font-size:12px;box-shadow:0 5px 20px #10251a30;z-index:100;opacity:0;pointer-events:none;transition:opacity .15s}.toast.visible{opacity:1}.candidate-list{display:flex;flex-wrap:wrap;gap:6px}.candidate-list button{font-size:12px}.ledger{font-size:11px;line-height:1.8;width:100%;border-collapse:collapse;margin-top:10px}.ledger th,.ledger td{border-bottom:1px solid #dce4d9;padding:6px 3px;text-align:left}.ledger th{font-weight:500;font-size:10px;color:#71816f}.pass{color:#207548}.fail{color:#a54535}.teacher .navigation{display:none}.teacher .app-shell{grid-template-columns:1fr}.teacher main{max-width:1650px}.teacher .task,.teacher .course-note{display:none}.teacher .workspace-grid{grid-template-columns:minmax(0,1fr) 245px}.teacher .stage{max-height:68vh;aspect-ratio:1.75}.teacher .reading-value{font-size:29px}.teacher #workspaces{display:none}.atom-counts{display:grid;grid-template-columns:1fr 70px;align-items:center;gap:8px;margin:9px 0;font-size:12px}.atom-counts input{width:100%}.instruction-small{font-size:11px;color:#879d8d}.stage-sr{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.stage-live-label{position:absolute;bottom:12px;left:18px;color:#7fa391;font-size:10px;pointer-events:none}.source-toggle{display:flex;align-items:center;gap:7px;font-size:11px;margin:13px 0}.footer-buttons{display:flex;gap:6px;flex-wrap:wrap}.teacher-workspaces{display:none}.teacher .teacher-workspaces{display:block;max-width:180px}.teacher select.teacher-workspaces{font-size:12px}.element-picker{width:100%}.track-legend{display:flex;gap:12px;flex-wrap:wrap;font-size:10px;color:#7b907e}.error-note{color:#a84731}.dragging{user-select:none}
@media(min-width:1600px){.app-shell{grid-template-columns:220px 1fr}.workspace-grid{grid-template-columns:minmax(0,1fr) 280px;gap:25px}.navigation{padding:30px 20px}.stage{max-height:620px}}
@media(max-width:1150px){.app-shell{grid-template-columns:159px minmax(0,1fr)}.navigation{padding:22px 8px}.lab-title{padding:0 9px 22px}.lab-title h1{font-size:16px}.lab-title .eyebrow{font-size:8px}.workspace-grid{grid-template-columns:minmax(0,1fr) 210px;gap:15px}main{padding:20px 17px}.stage{min-height:300px;aspect-ratio:1.4}.brand-name small{display:none}.reading-value{font-size:21px}#workspaces button{font-size:12px;gap:7px;padding-left:8px}.nav-symbol{width:19px}}
@media(max-width:900px){.app-shell{grid-template-columns:1fr}.navigation{padding:10px 16px;border-right:0;border-bottom:1px solid var(--border);display:block}.lab-title,.nav-footer{display:none}#workspaces{display:flex;flex-direction:row;flex-wrap:wrap;gap:4px}#workspaces button{padding:7px 10px;min-height:33px;font-size:11px}.nav-symbol{font-size:16px;width:16px}.workspace-grid{grid-template-columns:minmax(0,1fr) 215px}.topbar{padding:12px 17px}.stage{aspect-ratio:1.4}.experiment-heading{margin-bottom:15px}h2{font-size:25px}.stage-top{padding:10px 12px}.top-actions button{font-size:11px}.course-label{font-size:0;gap:0}.brand-name{font-size:16px}.transport{padding:11px}.transport button{font-size:10px;padding:7px 8px}.readings{gap:10px;margin:0 11px 10px}.reading-label{font-size:9px}.reading-value{font-size:19px}.reading-detail{font-size:9px}}
@media(max-width:680px){.topbar{gap:10px;flex-wrap:wrap;padding:10px 13px}.brand-name small{display:none}.brand-name{font-size:15px}.brand-mark{font-size:22px}.brand-mark span{font-size:18px}.top-actions{gap:5px;margin-left:auto}.top-actions button{min-height:34px;padding:6px 8px}#fullscreen span{display:none}.course-label select{max-width:119px;font-size:11px;padding:5px}.navigation{padding:9px 10px}#workspaces{gap:3px}#workspaces button{font-size:10px;padding:6px 8px;min-height:32px}.nav-symbol{font-size:15px;width:14px}main{padding:17px 12px}.experiment-heading{align-items:flex-start;gap:10px;flex-wrap:wrap}.experiment-select{min-width:0;max-width:none;width:100%}.experiment-select label{display:none}.experiment-select select{width:100%;font-size:12px}.workspace-grid,.teacher .workspace-grid{grid-template-columns:1fr;gap:14px}.stage{aspect-ratio:1.45;min-height:270px}.stage-top{font-size:10px;gap:5px}.stage-top>div{gap:6px}.stage-top button{font-size:9px}.state-dot{max-width:115px;font-size:9px}.inspector{background:#edf2e9;border:1px solid var(--border);border-radius:10px;padding:15px}.inspector-heading{margin-bottom:13px}.task{margin-bottom:14px}.task h3{font-size:14px}.task p,.task ol{font-size:12px}#controls{display:grid;grid-template-columns:1fr 1fr;gap:0 17px}.control-group{grid-column:1/-1}.field{margin-bottom:12px}.field-heading{font-size:12px}.field>select{font-size:13px;min-height:40px}.number-range{gap:6px}.number-range input[type=number]{width:63px;font-size:14px}.control-help,.selected-track,.model-info{font-size:11px}.button-row button,.wide-button{font-size:12px;min-height:38px}.wide-button,.selected-track,.candidate-list,.ledger,.source-toggle,.control-help,.atom-counts,.element-picker{grid-column:1/-1}.notebook-bar{padding:8px;gap:3px}.notebook-bar button{font-size:10px;padding:6px 8px}.notebook-actions{gap:0}.readings{gap:12px}.reading-label{font-size:10px}.reading-value{font-size:21px}.reading-detail{font-size:10px}.teacher .stage{max-height:none;aspect-ratio:1.45}.evidence-toolbar{gap:8px}.evidence-toolbar label{flex-wrap:wrap}.evidence-toolbar>button{margin:0}.clock{font-size:12px}.top-actions .teacher-workspaces{max-width:120px}input[type=range]{min-height:28px}}
@media(max-width:380px){.brand-name{display:none}.stage-top{flex-wrap:wrap}.stage{min-height:245px}.notebook-actions{margin-left:0}.reading-value{font-size:18px}.transport{gap:5px}.transport button{padding:6px}.clock{font-size:11px}.top-actions{gap:4px}#controls{grid-template-columns:1fr}.task h3{font-size:13px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}

/* Scientific motion uses the JS clock and retained SVG elements. OS motion
   preferences only remove decoration; they never stop a reaction or graph. */
.brand img{display:block;width:160px;height:auto;max-width:100%;object-fit:contain}
.stage{touch-action:pan-y}.stage .handle{touch-action:none;cursor:grab}
.stage .handle:focus-visible>rect:first-child{stroke:#f3c56d;stroke-width:3}
.stage[data-workspace=decay],.teacher .stage[data-workspace=decay]{height:clamp(360px,44vh,440px)}
.stage[data-workspace=decay].compact-decay,.teacher .stage[data-workspace=decay].compact-decay{height:450px;min-height:450px}
.stage svg [data-part],.stage svg [data-nucleus],.stage svg [data-neutron],.stage svg [data-plasma]{transition:none}
@media(prefers-reduced-motion:reduce){.stage .decorative{display:none}}
@media(max-width:680px){.brand img{width:133px}.stage[data-workspace=decay],.teacher .stage[data-workspace=decay]{height:450px;min-height:450px}.topbar{align-items:center}.top-actions{flex-wrap:wrap}}

@media(max-width:900px){.navigation .nav-footer{display:flex;flex-direction:row;flex-wrap:wrap;padding:7px 0 0;margin:0;gap:12px}.nav-footer .local-note{display:none}.nav-footer button{padding:3px;min-height:28px}}

.stage{height:clamp(280px,44vh,460px);aspect-ratio:auto}.teacher .stage{height:clamp(280px,58vh,620px);max-height:none;aspect-ratio:auto}@media(max-width:680px){.stage,.teacher .stage{height:285px;min-height:270px}}

.analysis-controls{display:flex;flex-wrap:wrap;align-items:center;gap:14px;padding:0 14px 12px;font-size:11px;color:#526d5c}.analysis-controls label{display:flex;align-items:center;gap:8px}.analysis-controls select{font-size:11px;min-height:30px}.analysis-result{margin:0 15px 14px;padding:12px 14px;background:#f0f5ec;border-left:3px solid #75a17c;font-size:12px;line-height:1.65;color:#3b5e48}.stage-tools progress{width:84px;height:7px;accent-color:#287050}.reading-settings{max-width:290px;white-space:normal;line-height:1.55;font-size:10px}.reading-settings summary{cursor:pointer;color:#31674b;font-weight:600}.reading-settings dl{display:grid;grid-template-columns:auto 1fr;gap:4px 10px}.reading-settings dt{color:#70816d}.reading-settings dd{margin:0;overflow-wrap:anywhere}@media(max-width:680px){.analysis-controls{gap:9px}.analysis-controls label{font-size:12px;flex-wrap:wrap}.analysis-controls select{font-size:12px;min-height:36px}.analysis-result{font-size:12px}}