*,*::before,*::after{box-sizing:border-box}
:root{--measure:70ch;--wide:1120px;--radius:3px;--serif:Georgia,"Times New Roman",serif;--sans:Arial,Helvetica,sans-serif;scroll-behavior:smooth}
html{font-size:100%;scroll-padding-top:76px}
body{margin:0;background:var(--paper,#fff);color:var(--ink,#1b1c1e);font-family:var(--serif);font-size:18px;line-height:1.68;text-rendering:optimizeLegibility}
a{color:var(--accent-text,#8f3d2a);text-decoration-thickness:.08em;text-underline-offset:.16em}
a:hover{text-decoration-thickness:.14em}
code{overflow-wrap:anywhere;border-radius:2px;background:var(--wash,#f0f2f4);padding:.12em .32em;font:0.86em/1.4 Consolas,"Courier New",monospace}
button,select,input{font:inherit}
button,select{min-height:44px;border:1px solid var(--control-border,#777f88);border-radius:2px;background:var(--paper,#fff);color:var(--ink,#1b1c1e)}
button{padding:.65rem 1rem;cursor:pointer}
button.primary{background:var(--ink,#1b1c1e);color:var(--paper,#fff);border-color:var(--ink,#1b1c1e);font-weight:700}
button:disabled,select:disabled,input:disabled{cursor:not-allowed;opacity:.58}
:focus-visible{outline:3px solid var(--accent-text,#8f3d2a);outline-offset:3px}
.skip-link{position:fixed;z-index:1000;top:8px;left:8px;transform:translateY(-180%);background:var(--ink);color:var(--paper);padding:.6rem .85rem}
.skip-link:focus{transform:none}
.site-header{position:sticky;z-index:50;top:0;display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:64px;border-bottom:1px solid var(--line,#d1d5db);background:color-mix(in srgb,var(--paper,#fff) 94%,transparent);padding:.65rem clamp(1rem,4vw,3rem);backdrop-filter:blur(12px)}
.brand{display:inline-flex;align-items:center;gap:.6rem;color:var(--ink);font:700 1rem/1 var(--sans);text-decoration:none;letter-spacing:.01em}
.brand-mark{display:grid;place-items:center;width:30px;height:30px;border:1px solid var(--ink);border-radius:50%;font:700 1.1rem/1 var(--serif)}
.header-right{display:flex;align-items:center;font:700 .76rem/1.2 var(--sans);text-transform:uppercase;letter-spacing:.05em}
.header-right>a{color:var(--ink)}
.hero{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(260px,.65fr);gap:clamp(2rem,6vw,6rem);align-items:end;max-width:var(--wide);margin:0 auto;padding:clamp(4rem,9vw,8rem) clamp(1rem,4vw,3rem) clamp(3rem,7vw,6rem)}
.kicker,.eyebrow,.figure-id,.toc-title{font:700 .7rem/1.4 var(--sans);letter-spacing:.14em;text-transform:uppercase;color:var(--quiet,#5f6268)}
.hero h1{max-width:820px;margin:.65rem 0 1.15rem;font-size:clamp(2.8rem,7.4vw,6.8rem);font-weight:400;line-height:.92;letter-spacing:-.055em}
.hero h1 em{color:var(--accent-text);font-weight:400}
.dek{max-width:58ch;margin:0;font-size:clamp(1.12rem,2vw,1.45rem);line-height:1.52;color:var(--quiet)}
.hero-meta{display:flex;flex-wrap:wrap;gap:.5rem 1.4rem;margin-top:1.6rem;font:700 .72rem/1.4 var(--sans);letter-spacing:.04em;text-transform:uppercase}
.hero-meta span{border-top:1px solid var(--line);padding-top:.45rem}
.hero-card{border-top:4px solid var(--accent);border-bottom:1px solid var(--line);background:var(--lab-surface,#f5f6f7);padding:1.4rem}
.hero-card code{display:block;margin:.5rem 0 1rem;background:none;padding:0;font-size:1.1rem}
.hero-card p{margin:.3rem 0 1rem;font-size:.94rem;line-height:1.5}
.hero-card a{font:700 .78rem/1.2 var(--sans)}
.reading-shell{display:grid;grid-template-columns:190px minmax(0,1fr);gap:clamp(2rem,5vw,5rem);max-width:var(--wide);margin:0 auto;padding:0 clamp(1rem,4vw,3rem) 6rem}
.contents nav{position:sticky;top:92px;border-top:2px solid var(--ink);padding-top:1rem}
.contents ol{margin:0;padding:0;list-style:none;counter-reset:item}
.contents li{border-top:1px solid var(--line);counter-increment:item}
.contents a{display:block;padding:.42rem 0;color:var(--quiet);font:600 .73rem/1.35 var(--sans);text-decoration:none}
.contents a:hover{color:var(--ink);text-decoration:underline}
.article{min-width:0;max-width:880px}
.article>h1:first-child,.article>h2:nth-child(2){position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}
.article h2{margin:5.5rem 0 1.25rem;padding-top:.8rem;border-top:1px solid var(--line);font-size:clamp(2rem,4.4vw,3.55rem);font-weight:400;line-height:1.05;letter-spacing:-.04em}
.article h3{margin:3.4rem 0 .8rem;font-size:clamp(1.35rem,2.6vw,2rem);font-weight:400;line-height:1.18;letter-spacing:-.022em}
.article h4{margin:1.5rem 0 .55rem;font:700 .96rem/1.35 var(--sans)}
.article p,.article>ul,.article>ol{max-width:var(--measure)}
.article li{margin:.3rem 0}
.article blockquote{margin:1.5rem 0;padding:.2rem 1.25rem;border-left:3px solid var(--accent);color:var(--quiet)}
.article blockquote p{margin:.55rem 0}
.case-note{max-width:var(--measure);margin:1.65rem 0;border-left:3px solid var(--accent);background:var(--lab-surface);padding:.85rem 1.2rem}
.case-note p{margin:.35rem 0;font-size:.95rem}
.table-scroll{max-width:100%;margin:1.5rem 0;overflow-x:auto;border:1px solid var(--line)}
table{width:100%;border-collapse:collapse;font:normal .79rem/1.5 var(--sans)}
th,td{vertical-align:top;border-bottom:1px solid var(--line);padding:.7rem .75rem;text-align:left}
thead th{position:sticky;top:0;background:var(--wash);font-size:.7rem;letter-spacing:.035em;text-transform:uppercase}
tbody th{min-width:120px;color:var(--ink)}
tbody tr:last-child>*{border-bottom:0}
.code-block{max-width:100%;overflow:auto;border:1px solid var(--line);background:var(--lab-surface);padding:1rem;font:normal .78rem/1.55 Consolas,"Courier New",monospace}
.equation{max-width:100%;margin:1.7rem 0;border-block:1px solid var(--line);overflow-x:auto;padding:1.15rem .25rem;text-align:center}
.equation math{min-width:max-content;font-size:1.1rem}
.equation-source{margin:.8rem auto 0;max-width:var(--measure);text-align:left;font:normal .7rem/1.45 var(--sans)}
.equation-source summary{cursor:pointer;color:var(--quiet)}
.equation-source code{display:block;margin-top:.4rem;white-space:normal}
.status{display:inline-block;border:1px solid currentColor;border-radius:999px;padding:.19rem .48rem;font:700 .61rem/1.25 var(--sans);letter-spacing:.08em;text-transform:uppercase}
.status-toy{color:var(--accent-text)}
.status-derived{color:var(--ink)}
.status-sourced{color:var(--ink);border-style:double}
.status-inferred{color:var(--quiet);border-style:dashed}
.status-unresolved{color:var(--quiet);border-style:dotted}
.figure{width:min(100%,1080px);margin:4.5rem 0;border-top:5px solid var(--ink);border-bottom:1px solid var(--line);background:var(--lab-surface);padding:clamp(1rem,3vw,2rem)}
.figure figcaption{margin-bottom:1.6rem}
.figure figcaption h2{margin:.35rem 0 .65rem;padding:0;border:0;font-size:clamp(1.7rem,3.4vw,2.65rem)}
.figure figcaption p{margin:.25rem 0;color:var(--quiet);font-size:.9rem}
.figure-takeaway{max-width:none!important;margin:1.4rem 0 0;border-top:1px solid var(--line);padding-top:1rem;font-size:.9rem}
.autopsy-rows{border-top:1px solid var(--line)}
.autopsy-row{display:grid;grid-template-columns:42px minmax(180px,1fr) minmax(220px,1.15fr) minmax(170px,.8fr);gap:1rem;align-items:start;border-bottom:1px solid var(--line);padding:1rem 0}
.autopsy-row h3{margin:0 0 .55rem;font:700 .88rem/1.35 var(--sans);letter-spacing:0}
.autopsy-row p{margin:.15rem 0;font-size:.76rem;line-height:1.45}
.tray-number{font:400 1.65rem/1 var(--serif);color:var(--accent-text)}
.failure{color:var(--quiet)}
.specimen{border-left:2px solid var(--accent);padding-left:.8rem}
.specimen span{display:block;margin-bottom:.25rem;font:700 .62rem/1 var(--sans);letter-spacing:.06em}
.mechanism-track{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:1px;margin:0;padding:0;background:var(--line);list-style:none}
.mechanism-track li{position:relative;min-height:230px;margin:0;background:var(--paper);padding:1rem}
.mechanism-track li:not(:last-child)::after{position:absolute;z-index:2;top:50%;right:-.63rem;content:"→";width:1.2rem;background:var(--paper);color:var(--accent-text);font:700 1rem/1 var(--sans);text-align:center}
.mechanism-track h3{margin:.7rem 0;font:700 .85rem/1.3 var(--sans);letter-spacing:0}
.mechanism-track p{font-size:.72rem;line-height:1.47}
.stage-number{display:grid;place-items:center;width:28px;height:28px;border:1px solid var(--ink);border-radius:50%;font:700 .68rem/1 var(--sans)}
.stage-stamp{position:absolute;right:1rem;bottom:1rem;left:1rem;border-top:1px solid var(--line);padding-top:.45rem;font:700 .58rem/1.3 var(--sans);letter-spacing:.06em;text-transform:uppercase}
.no-gradient{margin:1rem 0 0;border:1px dashed var(--control-border);padding:.75rem 1rem;font:700 .72rem/1.4 var(--sans)}
.no-gradient span{margin-right:.5rem;color:var(--accent-text);font-size:1.35rem}
.matrix-compact{display:none}
.axis-matrix{min-width:900px;font-size:.7rem}
.axis-matrix td:not(:empty):not(:has(>small)){background:var(--paper)}
.axis-lesson{display:flex;flex-wrap:wrap;gap:.7rem;margin-top:1rem}
.axis-lesson span{flex:1 1 290px;border-left:3px solid var(--accent);background:var(--paper);padding:.7rem;font:700 .72rem/1.45 var(--sans)}
.probability-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1rem}
.prob-card{border:1px solid var(--line);background:var(--paper);padding:1rem}
.prob-card.excluded{border-style:dashed;opacity:.86}
.prob-card header{display:flex;justify-content:space-between;gap:.5rem;margin-bottom:1rem;border-bottom:1px solid var(--line);padding-bottom:.75rem}
.prob-card header p{margin:0;color:var(--quiet);font:normal .64rem/1.3 var(--sans)}
.prefix{display:block;font:700 1.25rem/1 var(--sans)}
.membership{align-self:start;border:1px solid currentColor;padding:.2rem .35rem;font:700 .54rem/1.2 var(--sans);letter-spacing:.06em}
.prob-row{display:grid;grid-template-columns:68px 1fr 40px;gap:.45rem;align-items:center;margin:.4rem 0;font:normal .64rem/1 var(--sans)}
.prob-row strong{text-align:right}
.bar-track{height:10px;border:1px solid var(--line);background:var(--wash)}
.bar{display:block;width:calc(var(--value) * 100%);height:100%;background:var(--ink)}
.bar-teacher{background:repeating-linear-gradient(135deg,var(--accent) 0 3px,transparent 3px 6px);outline:1px solid var(--accent)}
.prob-card dl{margin:1rem 0 0;border-top:1px solid var(--line);font:normal .66rem/1.35 var(--sans)}
.prob-card dl div{display:flex;justify-content:space-between;gap:.5rem;padding-top:.5rem}
.prob-card dt{color:var(--quiet)}
.prob-card dd{margin:0;font-weight:700;text-align:right}
.mean-strip{display:grid;grid-template-columns:1fr 1fr;gap:1px;margin-top:1rem;background:var(--line)}
.mean-strip>div{display:grid;grid-template-columns:1fr auto;gap:.2rem 1rem;background:var(--paper);padding:1rem;font:normal .72rem/1.3 var(--sans)}
.mean-strip strong{font-size:1rem}
.mean-strip small{grid-column:1/-1;color:var(--quiet)}
.pair-grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
.pair-card{border:1px solid var(--line);background:var(--paper);padding:1rem}
.pair-card header>span{font:700 .6rem/1 var(--sans);letter-spacing:.1em}
.pair-card header p{font-size:.72rem;line-height:1.4}
.pair-cases{display:grid;grid-template-columns:1fr;gap:.5rem;margin:.8rem 0;text-align:center;font:700 .72rem/1.35 var(--sans)}
.pair-cases span{border-block:1px solid var(--accent);color:var(--accent-text);padding:.5rem}
.pair-card>p{font-size:.76rem}
.misconception-groups{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--line)}
.misconception-groups section{background:var(--paper);padding:1rem}
.misconception-groups h3{margin:0;font:700 .75rem/1.3 var(--sans)}
.misconception-groups p{font:normal .68rem/1.7 var(--sans)}
.challenge,.open-key{margin:5rem 0;border-top:7px solid var(--accent);border-bottom:1px solid var(--line);background:var(--lab-surface);padding:clamp(1rem,4vw,2.5rem)}
.challenge>header h2,.open-key>header h2{margin:.35rem 0 .7rem;padding:0;border:0;font-size:clamp(1.8rem,4vw,3rem)}
.challenge>header p,.open-key>header p{color:var(--quiet)}
.noscript-note{border:2px solid var(--accent);background:var(--paper);padding:1rem}
.control-group>label,.objective-control>label{display:block;margin-bottom:.45rem;font:700 .82rem/1.3 var(--sans)}
.control-group select{width:100%;padding:.55rem .7rem}
.blind-record{margin:1.25rem 0;border:1px solid var(--line);border-left:5px solid var(--accent);background:var(--paper);padding:1.1rem}
.blind-record h3{margin:.45rem 0 .6rem;font-size:1.25rem}
.blind-record p{font-size:.88rem}
.blind-record details{font:normal .73rem/1.45 var(--sans)}
.diagnosis-grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
fieldset,.objective-control{min-width:0;margin:0;border:1px solid var(--line);background:var(--paper);padding:1rem}
legend{padding:0 .35rem;font:700 .82rem/1.3 var(--sans)}
fieldset label{display:flex;gap:.55rem;align-items:flex-start;margin:.55rem 0;font:normal .75rem/1.4 var(--sans)}
fieldset input{flex:0 0 auto;margin-top:.15rem}
.field-help,.field-error{margin:.2rem 0 .7rem!important;font:normal .7rem/1.4 var(--sans);color:var(--quiet)}
.field-error{color:var(--accent-text);font-weight:700}
.button-row{display:flex;gap:.7rem;margin:1rem 0}
.interaction-status{min-height:2.8rem;border-left:3px solid var(--accent);background:var(--paper);padding:.6rem .8rem;font:700 .76rem/1.45 var(--sans)}
.diagnosis-reveal{margin-top:1rem;border-top:2px solid var(--ink);padding-top:1rem}
.diagnosis-reveal h3{margin:.4rem 0 1rem;font-size:1.55rem}
.axis-feedback{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
.axis-card{border:1px solid var(--line);background:var(--paper);padding:1rem}
.axis-card h4{margin:0 0 .45rem}
.axis-card p{font-size:.78rem}
.axis-match{border-top:4px solid var(--ink)}
.axis-review{border-top:4px dashed var(--accent)}
#five-field-autopsy ol,.autopsy-key ol{margin:0;padding:0;list-style:none;counter-reset:autopsy}
#five-field-autopsy li,.autopsy-key li{display:grid;grid-template-columns:minmax(180px,.75fr) minmax(0,1.5fr);gap:.75rem;border-top:1px solid var(--line);padding:.7rem 0;counter-increment:autopsy;font:normal .76rem/1.45 var(--sans)}
#five-field-autopsy li strong::before,.autopsy-key li strong::before{content:counter(autopsy) ". ";color:var(--accent-text)}
.counterexample{margin-top:1rem;border-left:3px solid var(--accent);background:var(--paper);padding:1rem}
.counterexample p{font-size:.78rem}
.boundary{color:var(--quiet)}
.key-record{margin:2rem 0;border:1px solid var(--line);background:var(--paper);padding:1.2rem;break-inside:avoid-page}
.key-record>header{display:grid;grid-template-columns:1fr 1.1fr;gap:1rem;align-items:start}
.key-record h3{margin:.45rem 0 .2rem;font-size:1.35rem}
.answer-pair{display:grid;grid-template-columns:1fr 1fr;gap:1px;margin:0;background:var(--line)}
.answer-pair div{background:var(--wash);padding:.65rem}
.answer-pair dt{font:700 .6rem/1.2 var(--sans);letter-spacing:.06em;text-transform:uppercase;color:var(--quiet)}
.answer-pair dd{margin:.25rem 0 0;font:700 .72rem/1.35 var(--sans)}
.record-copy{font-size:.84rem}
.key-record .boundary{font-size:.78rem}
footer{display:flex;justify-content:space-between;gap:2rem;border-top:1px solid var(--line);padding:2rem clamp(1rem,4vw,3rem);font:normal .72rem/1.4 var(--sans)}
footer p{margin:0}

@media(max-width:900px){
  .hero{grid-template-columns:1fr}.hero-card{max-width:520px}
  .reading-shell{grid-template-columns:1fr}.contents{display:none}
  .article{max-width:none}
  .autopsy-row{grid-template-columns:36px 1fr}.autopsy-row>div:nth-child(3),.autopsy-row>.specimen{grid-column:2}
  .mechanism-track{grid-template-columns:1fr}.mechanism-track li{min-height:0;padding:1rem 1rem 1.1rem 3.6rem}.mechanism-track li:not(:last-child)::after{top:auto;right:auto;bottom:-.63rem;left:1.2rem;content:"↓"}.stage-number{position:absolute;top:1rem;left:.7rem}.stage-stamp{position:static;display:block;margin-top:.8rem}
  .matrix-wide{display:none}.matrix-compact{display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--line)}.matrix-compact section{background:var(--paper);padding:1rem}.matrix-compact h3{margin:0;font:700 .75rem/1.3 var(--sans)}.matrix-compact ul{padding-left:1rem;font:normal .7rem/1.45 var(--sans)}
  .probability-grid{grid-template-columns:1fr}.prob-card.excluded{margin-top:.5rem}
  .misconception-groups{grid-template-columns:1fr 1fr}
}

@media(max-width:600px){
  body{font-size:16px}.site-header{position:relative;align-items:flex-start}.header-right{flex-direction:column;align-items:flex-end}.header-right>a{max-width:130px;text-align:right}
  .hero{padding-top:3rem}.hero h1{font-size:clamp(2.65rem,15vw,4.4rem)}
  .reading-shell{padding-inline:1rem}.article h2{margin-top:4.5rem}
  .autopsy-row{gap:.55rem}.pair-grid,.diagnosis-grid,.axis-feedback,.key-record>header,.answer-pair,.mean-strip{grid-template-columns:1fr}
  .matrix-compact,.misconception-groups{grid-template-columns:1fr}
  .button-row{flex-direction:column}.button-row button{width:100%}
  #five-field-autopsy li,.autopsy-key li{grid-template-columns:1fr;gap:.25rem}
  .table-scroll{margin-inline:0}
  footer{flex-direction:column}
}

@media(max-width:350px){
  .hero,.reading-shell{padding-inline:.75rem}.figure,.challenge,.open-key{margin-inline:-.25rem;padding-inline:.75rem}
  .hero-meta{display:grid}.prob-row{grid-template-columns:64px 1fr 36px}
}

@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}

@media(forced-colors:active){.status,.membership,.stage-number,.prob-card,.pair-card,.axis-card,.key-record{forced-color-adjust:auto}.bar{background:CanvasText}.bar-teacher{background:repeating-linear-gradient(135deg,CanvasText 0 2px,Canvas 2px 5px);outline:1px solid CanvasText}.axis-match{border-top-style:double}.axis-review{border-top-style:dashed}}

@page{size:A4;margin:15mm 14mm 18mm}
@media print{
  html{font-size:9.5pt;scroll-padding:0}body{font-size:10pt;line-height:1.42}
  .site-header{position:static;padding:0 0 8mm;border-bottom:1px solid #444}.header-right{display:none}.brand{font-size:10pt}.brand-mark{width:22px;height:22px}
  .hero{display:block;max-width:none;padding:13mm 0 8mm}.hero h1{font-size:34pt}.hero-card{display:none}.hero-meta{font-size:7pt}
  .reading-shell{display:block;max-width:none;padding:0}.contents{display:none}.article{max-width:none}
  .article h2{margin:12mm 0 4mm;break-after:avoid-page;font-size:21pt}.article h3{margin:8mm 0 3mm;break-after:avoid-page;font-size:15pt}
  .article p,.article>ul,.article>ol{max-width:none}
  a{color:#111;text-decoration:none}a[href^="http"]::after{content:" [source]";font:normal 7pt var(--sans)}
  .case-note,.equation,.figure,.challenge,.open-key,.key-record{break-inside:avoid-page}
  .table-scroll{overflow:visible;border-color:#777;break-inside:auto}table{font-size:7pt}thead{display:table-header-group}tr{break-inside:avoid-page}thead th{position:static}
  .equation{overflow:visible}.equation-source{display:none}
  .figure{margin:10mm 0;background:#fff;border-color:#222;padding:5mm}.figure figcaption h2{font-size:17pt}
  .mechanism-track{grid-template-columns:1fr 1fr}.mechanism-track li{min-height:0;break-inside:avoid}.mechanism-track li::after{display:none}.stage-stamp{position:static;display:block;margin-top:4mm}
  .matrix-wide{display:block}.matrix-compact{display:none}.axis-matrix{min-width:0;font-size:6.3pt}
  .probability-grid{grid-template-columns:1fr 1fr}.prob-card.excluded{grid-column:1/-1}.pair-grid{grid-template-columns:1fr 1fr}.misconception-groups{grid-template-columns:1fr 1fr}
  .screen-challenge{display:none}.print-practice{display:block}.open-key{margin-top:8mm}.key-record{break-inside:avoid-page}
  .theme-toggle,.interaction-status,.button-row,form{display:none!important}
  .skip-link{display:none!important}
  .figure.autopsy-sheet{break-inside:auto;page-break-inside:auto}
  .figure.autopsy-sheet figcaption{break-inside:avoid-page;page-break-inside:avoid;break-after:avoid-page;page-break-after:avoid}
  .autopsy-row{break-inside:avoid-page;page-break-inside:avoid}
  footer{margin-top:12mm;padding:5mm 0 0;font-size:7pt}
}