:root{color-scheme:dark;--bg:#0c1824;--panel:#112333;--stage:#102333;--line:#294252;--ink:#edf3f6;--muted:#9db3c2;--gold:#f3be87;--mint:#8de7ce;--field:#65c7e6;--control:#183140;--lead:#91acbb;font-family:'Segoe UI',system-ui,sans-serif}
:root[data-theme=light]{color-scheme:light;--bg:#edf2f4;--panel:#fbfdfe;--stage:#e9f1f5;--line:#ccdae0;--ink:#1d3748;--muted:#526c7d;--gold:#925624;--mint:#147b65;--field:#197ea3;--control:#f0f5f7;--lead:#3c5868}
*{box-sizing:border-box}body{margin:0;padding:22px max(24px,env(safe-area-inset-right)) max(84px,env(safe-area-inset-bottom)) max(24px,env(safe-area-inset-left));background:var(--bg);color:var(--ink)}button,input,select{font:inherit;touch-action:manipulation}button{cursor:pointer;min-height:44px;border:1px solid var(--line);border-radius:12px;padding:10px 17px;background:var(--control);color:var(--ink);font-size:13px;font-weight:550}button:hover{background:color-mix(in srgb,var(--ink) 7%,var(--control));border-color:var(--muted)}button:disabled{opacity:.4;cursor:default}button:focus-visible,input:focus-visible,select:focus-visible,canvas:focus-visible,a:focus-visible{outline:3px solid var(--field);outline-offset:4px}[hidden]{display:none!important}a{text-decoration:none;color:var(--ink)}.page-header,main{max-width:1480px;margin:auto}.page-header{display:flex;align-items:center;gap:14px;margin-bottom:22px}.back{display:grid;place-items:center;width:44px;height:44px;border:1px solid var(--line);border-radius:13px;font-size:23px}.heading{flex:1}.eyebrow{color:var(--muted);font-size:10px;font-weight:600;letter-spacing:.16em}h1{font-size:clamp(21px,2.1vw,30px);letter-spacing:-.025em;margin:4px 0 0;font-weight:630}h2{font-size:20px;margin:0 0 5px;font-weight:600;letter-spacing:-.02em}.page-header button{background:transparent;font-size:12px}.experiment{overflow:hidden;background:var(--panel);border:1px solid var(--line);border-radius:24px;box-shadow:0 18px 50px #00000012}.experiment-top{min-height:58px;padding:12px 28px;display:flex;justify-content:space-between;align-items:center;gap:16px;border-bottom:1px solid var(--line)}.experiment-top p{margin:0;font-size:13px;letter-spacing:.01em}.experiment-top p span{padding:0 12px;color:var(--gold)}.live{font-size:11px;color:var(--mint);white-space:nowrap;padding:6px 10px;background:color-mix(in srgb,var(--mint) 7%,var(--panel));border-radius:20px}.live:before{content:'';display:inline-block;width:6px;height:6px;background:currentColor;border-radius:50%;margin-right:7px}.stage{height:clamp(475px,59vh,680px);position:relative;isolation:isolate;background:radial-gradient(ellipse at 34% 35%,color-mix(in srgb,var(--field) 9%,var(--stage)),var(--stage) 65%)}#scene{display:block;width:70%;height:100%;touch-action:none;cursor:grab}#scene:active{cursor:grabbing}.scene-heading{position:absolute;left:32px;top:24px;display:flex;gap:12px;align-items:center;z-index:2;pointer-events:none}.section-number{font-size:11px;color:var(--muted);width:31px;height:31px;border:1px solid var(--line);border-radius:50%;display:grid;place-items:center;flex:none}.scene-heading p,.instrument-heading p{margin:0;color:var(--muted);font-size:12px;line-height:1.6}.scene-heading h2{color:var(--gold)}.instrument{position:absolute;right:4%;top:50%;transform:translateY(-54%);width:25%;max-width:350px;min-width:235px;z-index:3;pointer-events:none}.instrument-heading{display:flex;align-items:center;gap:12px;margin-bottom:20px}.instrument h2{font-size:23px}#dial{display:block;width:100%;height:auto;overflow:visible;filter:drop-shadow(0 12px 14px #00000028)}.dial-half{fill:none;stroke-width:12;opacity:.13}.dial-half.negative{stroke:#438b98}.dial-half.positive{stroke:#bd7850}.dial-arc,.dial-ticks{fill:none;stroke:#4c6872;stroke-width:1.6}.dial-numbers{fill:#2b4955;text-anchor:middle;font:600 13px 'Segoe UI',sans-serif}.dial-numbers .zero{font-size:24px}.dial-unit{font-size:22px}.dial-numbers .polarity{font-size:25px;fill:#7d969d}.dial-brand{fill:#3d5c67;text-anchor:middle;letter-spacing:.17em;font:600 10px 'Segoe UI',sans-serif}#dial-needle{fill:#c95140;stroke:#c95140;stroke-width:1}.meter-reading{margin:25px 0 0;text-align:center;font-variant-numeric:tabular-nums;line-height:1.1}.meter-reading output{font-size:30px;font-weight:600;letter-spacing:-.03em}.meter-reading>span:not(.current-direction){color:var(--muted);font-size:12px;margin-left:4px}.current-direction{display:block;color:var(--mint);font-size:12px;margin-top:9px;min-height:16px}.current-direction[data-sign=negative]{color:var(--field)}#connections{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;z-index:1;overflow:hidden}#connections>path{fill:none;stroke-linecap:round}.lead-shadow{stroke:var(--stage);stroke-width:9}.red-lead{stroke:#e78470;stroke-width:3.5}.black-lead{stroke:var(--lead);stroke-width:3.5}.lead-arrows path{fill:none;stroke:var(--mint);stroke-width:3;stroke-linecap:round;stroke-linejoin:round}#view-message{position:absolute;top:100px;left:32px;right:32px;color:var(--gold);font-size:13px;pointer-events:none;z-index:4}#view-message:empty{display:none}.scene-tools{position:absolute;left:28px;bottom:20px;display:flex;align-items:center;gap:12px;z-index:2}.scene-tools>span{font-size:11px;color:var(--muted)}.scene-tools button{font-size:11px;padding:7px 12px;background:var(--stage)}.legend{position:absolute;right:28px;bottom:25px;display:flex;gap:18px;z-index:2;font-size:11px;color:var(--muted);pointer-events:none}.legend span{display:flex;align-items:center;gap:7px}.legend i{display:inline-block;width:16px;height:3px;border-radius:3px}.field-dot{background:var(--field)}.current-dot{background:var(--mint)}.main-controls{display:flex;justify-content:center;align-items:center;gap:20px;padding:22px 28px;border-top:1px solid var(--line)}button.primary{background:#efc191;color:#253240;border-color:#efc191;min-width:153px;min-height:49px;font-size:14px}button.primary:hover{background:#ffdab0}.speed-control{width:300px;padding:0 22px;border-left:1px solid var(--line);border-right:1px solid var(--line)}.speed-control>div:first-child{display:flex;justify-content:space-between;font-size:12px;gap:8px;align-items:baseline}.speed-control>div:first-child>span{color:var(--gold);font-size:11px;font-variant-numeric:tabular-nums}.range-ends{display:flex;justify-content:space-between;color:var(--muted);font-size:9px}.button-symbol{font-size:19px;vertical-align:-1px;padding-right:5px}input[type=range]{width:100%;min-height:28px;margin:2px 0;accent-color:#dfb27f;cursor:pointer}#reverse[aria-pressed=true]{color:var(--gold);border-color:var(--gold)}.observation-note{display:flex;align-items:center;justify-content:center;gap:12px;padding:14px 20px;background:color-mix(in srgb,var(--mint) 4%,var(--panel));border-top:1px solid var(--line)}.note-mark{color:var(--mint);font-size:20px}.observation-note p{margin:0;font-size:13px;color:var(--muted);line-height:1.6}.observation-note strong{font-weight:600;color:var(--ink)}.secondary-controls{display:flex;align-items:center;justify-content:space-between;margin:13px 5px 0;gap:15px}.structure-toggle{display:flex;align-items:center;gap:9px;font-size:13px;cursor:pointer;min-height:44px}.structure-toggle input,.check input{width:18px;height:18px;accent-color:#bd945f;cursor:pointer}#advanced-toggle{background:transparent;border-color:transparent;color:var(--muted);font-weight:500}#advanced-toggle span{padding-left:9px;display:inline-block}#advanced-toggle[aria-expanded=true] span{transform:rotate(180deg)}#structure-note{margin:0 5px 15px;color:var(--muted);font-size:12px;line-height:1.8}.advanced{margin-top:12px;border:1px solid var(--line);border-radius:18px;background:var(--panel);padding:24px;display:grid;grid-template-columns:1fr 1fr 1fr;gap:30px}.number-label{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:12px;margin-bottom:12px}.number-label span{display:flex;align-items:center;gap:7px;white-space:nowrap;color:var(--muted);font-size:11px}input[type=number],select{background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:9px;min-height:40px}input[type=number]{width:74px}select{font-size:12px}.advanced-controls>input[type=range]{margin:-5px 0 14px}.check{display:flex;align-items:center;gap:8px;font-size:12px;min-height:32px}.freeze-controls{display:flex;gap:6px;margin-top:12px}.freeze-controls button{font-size:11px;padding:8px 10px}.advanced-display p{font-size:10px;color:var(--muted);margin:8px 0 0}.advanced-readings>div{display:flex;justify-content:space-between;align-items:baseline;gap:8px;padding:11px 0;border-bottom:1px solid var(--line);font-variant-numeric:tabular-nums;font-size:15px}.advanced-readings>div>span:first-child{color:var(--muted);font-size:12px}.formula{grid-column:1/-1;display:flex;justify-content:space-between;gap:15px;font-size:12px;color:var(--muted);border-top:1px solid var(--line);padding-top:17px}.formula>span:first-child{color:var(--gold)}
@media(min-width:1700px){.stage{height:650px}}
@media(max-width:1100px){body{padding:18px 18px 84px}.stage{height:520px}#scene{width:68%}.instrument{right:3%;width:27%;min-width:220px}.instrument-heading{margin-bottom:16px}.main-controls{gap:12px;padding:20px}.speed-control{width:270px;padding:0 16px}.legend{gap:10px;font-size:10px}.scene-heading{left:25px}.scene-tools{left:25px}.experiment-top{padding:13px 22px}.experiment-top p{font-size:12px}.experiment-top p span{padding:0 7px}}
@media(max-width:780px){body{padding:15px 12px 84px}.page-header{flex-wrap:wrap;gap:10px;margin-bottom:16px}.heading{min-width:230px}h1{font-size:23px}.page-header button{font-size:11px;padding:8px 11px}.fullscreen{display:none}.experiment{border-radius:19px}.experiment-top{padding:12px 17px;gap:8px}.experiment-top p{font-size:11px;line-height:1.7}.experiment-top p span{padding:0 4px}.live{font-size:10px}.stage{height:480px}.scene-heading{top:22px;left:20px}.scene-heading h2{font-size:18px}.scene-heading p{font-size:10px}.section-number{display:none}#scene{width:65%}.instrument{min-width:185px;right:3%;width:29%}.instrument h2{font-size:19px}.instrument-heading p{font-size:11px}.meter-reading output{font-size:25px}.current-direction{font-size:10px}.legend{right:18px;bottom:27px;flex-direction:column;gap:7px}.scene-tools{left:18px;bottom:20px;gap:6px}.scene-tools>span{display:none}.main-controls{flex-wrap:wrap;gap:13px;padding:19px 15px}.speed-control{flex:1;min-width:230px;border-right:0;padding-right:0}.main-controls>button:not(.primary){font-size:12px}.observation-note p{font-size:12px}.observation-note{gap:8px;padding:12px 15px}.advanced{grid-template-columns:1fr 1fr;gap:22px;padding:20px}.advanced-readings{grid-column:1/-1;display:grid;grid-template-columns:1fr 1fr;gap:0 25px}.formula{flex-direction:column;font-size:11px;gap:8px}}
@media(max-width:560px){body{padding:14px 10px 84px}.back{width:37px;height:40px}.heading{min-width:200px}.heading h1{font-size:20px}.eyebrow{font-size:9px}.page-header>button{margin-left:47px;min-height:34px;font-size:10px;padding:6px 10px}.experiment-top{display:block;padding:12px 17px}.experiment-top p{font-size:11px}.live{display:none}.stage{height:705px}.scene-heading{top:19px;left:19px}.scene-heading h2{font-size:18px}.scene-heading p{font-size:11px}#scene{width:100%;height:370px}.instrument{top:380px;bottom:auto;left:50%;right:auto;width:245px;max-width:68%;min-width:210px;transform:translateX(-50%)}.instrument-heading{margin-bottom:12px;display:block;text-align:center}.instrument-heading h2{font-size:18px;margin-bottom:2px}.instrument-heading p{font-size:10px}.meter-reading{margin-top:17px}.meter-reading output{font-size:25px}.current-direction{font-size:11px}.scene-tools{top:18px;right:14px;left:auto;bottom:auto}.scene-tools button{font-size:10px;padding:5px 8px;min-height:34px}.legend{left:18px;right:18px;bottom:auto;top:345px;flex-direction:row;justify-content:center;gap:18px;font-size:10px}.main-controls{gap:12px;padding:18px 15px}.main-controls .primary{min-width:130px;font-size:13px}.speed-control{min-width:130px;width:auto;padding-left:13px}.speed-control>div:first-child{display:block;font-size:11px}.speed-control>div:first-child>span{display:block;font-size:10px;margin-top:4px}.range-ends{display:none}.main-controls>button:not(.primary){flex:1;padding:7px 10px}.observation-note{align-items:flex-start}.observation-note p{font-size:11px}.secondary-controls{gap:4px;margin-top:10px}.structure-toggle{font-size:12px}#advanced-toggle{font-size:12px;padding:9px}.advanced{grid-template-columns:1fr;padding:18px;gap:20px}.advanced-readings{grid-column:auto;grid-template-columns:1fr}.formula{grid-column:auto}.check{min-height:40px}#view-message{left:20px;top:82px;font-size:11px}}
@media(pointer:coarse){input[type=range]{min-height:34px}input[type=number]{min-height:44px}}
#utility-dock{display:flex;align-items:center;justify-content:space-between;gap:14px;max-width:1480px;margin:18px auto 0;min-height:48px}#assistant-open{font-size:12px;background:transparent;color:var(--muted)}#utility-dock .pylab-sound{position:relative;right:auto;bottom:auto;margin-left:auto;z-index:20}#utility-dock .sound-settings{z-index:21}
@media(max-width:560px){.main-controls{display:grid;grid-template-columns:1fr 1fr}.main-controls button{white-space:nowrap}.speed-control{width:100%;min-width:0}.main-controls>button:not(.primary){min-width:0}.scene-heading{max-width:calc(100% - 115px)}#utility-dock{margin-top:14px}body{padding-bottom:max(24px,env(safe-area-inset-bottom))}}

/* Keep the branch colours consistent from loop ends to meter terminals. */
.branch-a{color:#f2a394}.branch-b{color:#8ac6ff}.black-lead{stroke:#79b6ee}.red-lead{stroke:#ef8a79}
:root[data-theme=light] .branch-a{color:#ac3b34}:root[data-theme=light] .branch-b{color:#2267a6}:root[data-theme=light] .black-lead{stroke:#377ebd}
@media(max-width:560px){.stage{height:760px}#scene{height:420px}.instrument{top:435px}.legend{top:403px}.scene-heading{max-width:calc(100% - 40px)}.scene-heading p{font-size:10px}.scene-tools{top:80px}}