:root{--paper:#f7f6f0;--ink:#19364e;--muted:#617380;--accent:#16858b;--line:#dce2df;--white:#fffefa;--blue:#294861;font-family:Inter,"Segoe UI","Microsoft YaHei",system-ui,sans-serif;color:var(--ink);background:var(--paper);font-synthesis:none}*{box-sizing:border-box}body{margin:0;line-height:1.7}a{color:inherit;text-decoration:none}button,input,select{font:inherit}button,.button{border:1px solid var(--line);border-radius:5px;padding:9px 18px;background:var(--white);color:var(--ink);cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:22px;line-height:1.6}button:hover,.button:hover{border-color:var(--accent)}button:disabled{opacity:.45;cursor:default}.primary{background:var(--ink);color:white;border-color:var(--ink)}.primary:hover{background:#27516c}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #2a969c;outline-offset:4px}.skip{position:absolute;top:-80px;background:white;padding:10px;z-index:5}.skip:focus{top:0}header{max-width:1440px;margin:auto;padding:25px 4.5%;display:flex;align-items:center;gap:45px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:12px;font-size:21px;font-weight:650;line-height:1.4}.brand small{display:block;font-size:11px;letter-spacing:2px;font-weight:400;color:var(--muted)}.brand-symbol{font-size:45px;color:var(--accent);line-height:1}nav{display:flex;gap:28px;margin-left:auto;font-size:14px}nav a[aria-current=page]{color:var(--accent)}nav a:hover,.text-link:hover{color:var(--accent)}.edition{font-size:12px;color:var(--muted);border-left:1px solid var(--line);padding-left:24px}main{max-width:1320px;padding:0 35px;margin:auto;min-height:75vh}.page[hidden]{display:none}.hero{display:grid;grid-template-columns:1.1fr 1fr;gap:75px;align-items:center;padding:73px 0 64px}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--accent);font-weight:650;margin:0 0 14px}h1,h2,h3,p{margin-top:0}h1{font-family:"Noto Serif SC","Songti SC",SimSun,serif;font-size:43px;line-height:1.5;font-weight:650;letter-spacing:1px;margin-bottom:20px}h2{font-size:19px;font-weight:600;margin-bottom:9px}h3{font-size:24px;margin:12px 0}.lead{font-size:16px;line-height:1.9;color:var(--muted);margin-bottom:28px}.text-link{display:block;font-size:13px;color:var(--muted);margin-top:18px}.hero-diagram{padding:24px 20px;background:#eeefE8;border:1px solid var(--line);border-radius:7px;transform:rotate(-1deg)}.hero-diagram p{font-size:11px;color:var(--muted);letter-spacing:2px}.hero-diagram svg{width:100%;font:17px Georgia,serif;fill:var(--ink)}.hero-equation{font:30px Georgia,serif;padding:12px 15px;display:flex;justify-content:space-between;align-items:center}.hero-equation span{font:12px "Microsoft YaHei",sans-serif;color:var(--muted)}.section-heading{display:flex;align-items:center;justify-content:space-between;gap:15px}.section-heading p{font-size:13px;color:var(--muted);margin:0}.experiments{display:grid;grid-template-columns:repeat(3,1fr);border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin-top:18px}.experiment{padding:27px 30px;position:relative}.experiment+.experiment{border-left:1px solid var(--line)}.experiment:hover{background:#efF1eb}.number{font:25px Georgia,serif;color:#8b9eA4}.tag{font-size:11px;color:#16767b;background:#e5eeE9;border-radius:3px;padding:3px 9px;float:right}.tag.muted{color:var(--muted);background:#e9eae4}.experiment p{font-size:13px;color:var(--muted);min-height:67px}.experiment-formula{font:25px Georgia,serif}.entry{display:block;margin-top:25px;font-size:12px;color:var(--accent)}.home-note{display:flex;gap:36px;margin:35px 0 55px;font-size:12px;color:var(--muted)}.home-note span{color:var(--ink);white-space:nowrap}.home-note p{margin:0}footer{max-width:1320px;margin:20px auto 0;padding:22px 35px;border-top:1px solid var(--line);display:flex;justify-content:space-between;color:var(--muted);font-size:11px}.lab-heading{display:flex;align-items:center;justify-content:space-between;padding:32px 0 24px}.lab-heading h1{font-size:31px;margin-bottom:4px}.lab-heading p:not(.eyebrow){margin:0;font-size:13px;color:var(--muted)}.lab-heading .eyebrow{margin-bottom:6px}.lab-layout{display:grid;grid-template-columns:265px minmax(0,1fr);gap:25px}.parameters{padding:22px;background:#eeF0e9;border:1px solid var(--line);border-radius:5px;align-self:start}.parameters h2{font-size:16px;margin:0}.quiet{padding:0;border:0;background:transparent;color:var(--accent);font-size:11px}.hint{color:var(--muted);font-size:11px;line-height:1.7;margin:7px 0}.param{padding:13px 0;border-bottom:1px solid var(--line)}.param:last-child{border:0}.param label{font-size:12px;display:flex;align-items:center;justify-content:space-between;gap:8px}.param input{width:87px;min-width:0;border:1px solid #c9d3d2;border-radius:4px;padding:4px 6px;background:var(--white);color:var(--ink);text-align:right}.param small{font-size:10px;color:var(--muted)}.param-error{font-size:11px;color:#a14030;min-height:0}.param input[aria-invalid=true]{border-color:#a14030}.scene-panel,.plot-panel{border:1px solid var(--line);background:var(--white);border-radius:5px;overflow:hidden}.scene-heading{padding:16px 22px 5px;display:flex;align-items:center;justify-content:space-between}.scene-heading h2{font-size:15px;margin:0}#status{font-size:11px;color:var(--accent)}.scene-legend{display:flex;gap:20px;font-size:10px;padding:0 22px;color:var(--muted)}.teal{color:var(--accent);fill:var(--accent)}#scene{width:100%;display:block;max-height:340px;font-size:13px;fill:var(--ink)}.rails{fill:none;stroke:#294861;stroke-width:3}.scene-caption{font-size:10px;text-align:center;color:var(--muted);margin:-3px 10px 10px}.controls{padding:13px 20px;display:flex;gap:9px;align-items:center;border-top:1px solid var(--line);background:#f5f6f0}.controls button{font-size:12px;padding:7px 15px}#clock{margin-left:auto;font-size:12px;font-variant-numeric:tabular-nums}.readouts{display:grid;grid-template-columns:repeat(4,1fr);margin:17px 0;border-block:1px solid var(--line);padding:17px 0}.readouts div{padding:0 18px;border-right:1px solid var(--line)}.readouts div:last-child{border:0}.readouts span{font-size:11px;color:var(--muted);display:block}.readouts strong{font-size:23px;font-weight:500;font-variant-numeric:tabular-nums;white-space:nowrap}.readouts small{font-size:11px;color:var(--muted)}.plot-panel{padding:18px 20px 10px}.plot-heading{display:flex;align-items:center;gap:16px}.plot-heading h2{font-size:15px;margin:0}.plot-heading .hint{margin:0}.plot-select{margin-left:auto;font-size:11px;white-space:nowrap}.plot-select select{display:block;max-width:220px;border:1px solid var(--line);padding:5px;color:var(--ink);background:var(--white);font-size:11px;border-radius:3px}#export{font-size:11px;white-space:nowrap;padding:7px 10px}#plot{width:100%;display:block;font:11px "Segoe UI","Microsoft YaHei",sans-serif;fill:var(--muted)}#feedback{font-size:11px;margin:0;color:var(--accent)}.principle{display:grid;grid-template-columns:1fr 1.6fr;gap:70px;padding:46px 0 30px}.principle p{font-size:12px;color:var(--muted)}.equations{font:22px/2 Georgia,"Times New Roman",serif;margin-bottom:14px;color:var(--ink)}.pending,.guide{max-width:850px;margin:auto;padding:70px 0}.pending .tag{float:none;display:inline-block;margin-bottom:15px}.pending p,.guide p{color:var(--muted);font-size:14px}.pending .button,.guide .button{margin-top:18px}.guide ol{padding-left:25px}.guide li{padding:14px 0 14px 13px}.guide h2{font-size:18px}.guide h1{font-size:35px}@media(min-width:1500px){main{max-width:1400px}.lab-layout{grid-template-columns:285px minmax(0,1fr)}}@media(max-width:950px){header{gap:20px}.edition{display:none}.hero{gap:30px;padding-top:45px}h1{font-size:34px}.lab-layout{grid-template-columns:220px minmax(0,1fr);gap:15px}.parameters{padding:15px}.readouts div{padding:0 10px}.readouts strong{font-size:18px}.plot-heading{flex-wrap:wrap}.plot-select{margin-left:0}.scene-legend{gap:10px;font-size:9px}.experiment{padding:23px 18px}.principle{gap:30px}}@media(max-width:680px){header{padding:17px 20px;flex-wrap:wrap;gap:14px}.brand{font-size:18px}.brand-symbol{font-size:35px}nav{gap:19px;font-size:12px;width:100%;margin:0}main{padding:0 20px}.hero{grid-template-columns:1fr;gap:35px;padding:38px 0}h1{font-size:32px}.hero-diagram{max-width:500px;transform:none;padding:15px}.hero-diagram svg{max-height:230px}.section-heading{align-items:flex-start;flex-wrap:wrap}.section-heading p{font-size:11px}.experiments{grid-template-columns:1fr}.experiment+.experiment{border-left:0;border-top:1px solid var(--line)}.experiment p{min-height:0}.experiment h3{font-size:21px}.entry{margin-top:15px}.home-note{display:block}.home-note span{display:block;margin-bottom:8px}.lab-heading{align-items:flex-start}.lab-heading h1{font-size:27px}.lab-heading .text-link{white-space:nowrap;font-size:11px}.lab-layout{display:flex;flex-direction:column}.parameters{width:100%}#parameters{display:grid;grid-template-columns:1fr 1fr;column-gap:18px}.param{padding:9px 0}.param label{display:block;font-size:11px}.param input{display:block;width:100%;text-align:left;margin-top:4px}.lab-main{min-width:0}.scene-heading{padding:14px 15px 5px}.scene-legend{padding:0 10px;gap:8px;font-size:8px}.scene-caption{font-size:9px;margin:0 8px 8px}.controls{padding:10px;flex-wrap:wrap}.controls button{padding:7px 11px}#clock{width:100%;text-align:right;font-size:11px}.readouts{grid-template-columns:1fr 1fr;gap:15px}.readouts div:nth-child(2){border:0}.readouts strong{font-size:23px}.plot-panel{padding:14px 10px 8px}.plot-heading{gap:10px}.plot-heading>div{width:100%}.plot-select{flex:1}#plot{min-height:170px}.principle{grid-template-columns:1fr;gap:12px;padding:32px 0}.equations{font-size:20px}.pending,.guide{padding:40px 0}.guide h1{font-size:29px}footer{padding:18px 20px;display:block}footer span{display:block}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto}}

/* Three-dimensional lab upgrade */
.hero-science{font:52px Georgia,serif;padding:55px 10px;color:var(--ink)}.hero-science span{font-size:35px}.hero-description{line-height:2!important;font-size:13px!important;letter-spacing:0!important;padding:0 12px}
#scene-host{position:relative;height:420px;width:100%;touch-action:none}#scene-host canvas{display:block;width:100%;height:100%}#scene-loading{position:absolute;inset:25px 15px auto;z-index:2;font-size:13px;background:#fffefa;padding:14px}.scene-toolbar{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:7px 20px;font-size:11px;color:var(--muted)}.scene-toolbar button{font-size:11px;padding:4px 10px}.part-info{padding:10px 18px;margin:0;border-top:1px solid var(--line);font-size:12px;color:var(--ink);min-height:44px}.initial-control{padding:12px 20px;border-top:1px solid var(--line);display:grid;grid-template-columns:130px 1fr 85px;align-items:center;gap:12px;font-size:12px}.initial-control input{width:100%;accent-color:var(--accent)}.initial-control output{text-align:right}.initial-control p{grid-column:1/-1;margin:0}.contact-info{font-size:12px;padding:0 5px;color:var(--muted);min-height:35px}.model-principle{color:var(--ink)!important;font-size:15px!important;line-height:2}#status{max-width:65%;text-align:right}.readouts strong{font-size:21px}.readouts span{min-height:38px}.scene-caption{margin:6px 15px 10px}nav{gap:20px}.readouts small{white-space:nowrap}
@media(max-width:900px){header{gap:20px}nav{gap:14px}.brand small{letter-spacing:0}.lab-layout{grid-template-columns:230px minmax(0,1fr)}.readouts{grid-template-columns:1fr 1fr;gap:12px}.readouts div:nth-child(2){border:0}#scene-host{height:360px}.initial-control{grid-template-columns:110px 1fr}.initial-control output{grid-column:2}}
@media(max-width:680px){header nav{gap:10px;flex-wrap:wrap}.lab-layout{display:flex}#scene-host{height:315px}.scene-toolbar{padding:8px 12px;flex-wrap:wrap;font-size:10px}.scene-toolbar button{font-size:11px}.initial-control{padding:10px 12px;gap:7px;grid-template-columns:100px 1fr}.part-info{font-size:11px;padding:9px 12px}.readouts strong{font-size:21px}.readouts span{min-height:25px}.contact-info{font-size:11px}#plot{font-size:15px}.hero-science{font-size:43px;padding:30px 5px}.hero-science span{font-size:28px}.model-principle{font-size:13px!important}}

[hidden]{display:none!important}
.view-switch,.layers,#field-tools,.record-controls{display:flex;flex-wrap:wrap;gap:10px;align-items:center;padding:12px 18px}.view-switch{border-top:1px solid var(--line)}.view-switch [aria-pressed=true]{background:#19364e;color:white}#field-tools{background:#f3f5ef;font-size:12px}.layers{font-size:12px;border-bottom:1px solid var(--line)}.layers label{display:flex;gap:5px;align-items:center}input[type=checkbox]{accent-color:#16858b;width:16px;height:16px}select{max-width:100%;padding:6px;border:1px solid var(--line);background:#fffefa;color:var(--ink)}#field-tools label,.record-controls label{display:flex;gap:8px;align-items:center}#field-legend{padding:12px 18px;background:#fafbf7;font-size:12px}#field-legend p{margin:8px 0 0;line-height:1.8}.color-ramp{display:inline-block;width:150px;height:12px;background:linear-gradient(90deg,hsl(194,72%,43%),hsl(39,72%,43%));margin-right:12px}.playback-note{padding:0 18px 12px}.controls{flex-wrap:wrap}.controls label{font-size:12px;display:flex;align-items:center;gap:8px}.record-tools{padding:22px 0;border-top:1px solid var(--line)}.record-controls{padding:12px 0;font-size:12px}.record-controls input[type=file]{max-width:190px;font-size:12px}.record-tools h2{font-size:19px}#plot-probe{display:block;font-size:12px;min-height:24px;padding:8px 0;color:var(--ink)}#plot{touch-action:pan-y}#parameter-toggle{display:none}body.focus-experiment header,body.focus-experiment .lab-heading,body.focus-experiment .parameters,body.focus-experiment .principle,body.focus-experiment footer{display:none}body.focus-experiment .lab-layout{grid-template-columns:minmax(0,1fr)}body.focus-experiment #scene-host{height:60vh;min-height:360px}body.focus-experiment #lab{max-width:1600px}#record-feedback{font-size:13px;color:var(--ink)}
@media(max-width:680px){#parameter-toggle{display:block;width:100%;margin-bottom:10px}.record-controls{display:grid;grid-template-columns:1fr}.record-controls label{flex-wrap:wrap}.view-switch,.layers,#field-tools{padding:10px 12px;gap:8px}.layers{font-size:11px}.controls #clock{width:100%;text-align:left}.controls button{padding:8px 10px}#field-tools label{width:100%;justify-content:space-between}.record-tools{padding:18px 10px}.color-ramp{width:100px}body.focus-experiment #scene-host{min-height:300px}}
