:root{--paper:#f7f7f2;--ink:#171916;--rule:#babeb3;--blue:#254dff;--amber:#a34700;--red:#b3261e;--muted:#53584d;--panel:#ecefe5;--display:Anton,'Arial Narrow','Helvetica Neue Condensed',Impact,sans-serif;--text:'Space Grotesk',system-ui,-apple-system,'Segoe UI',sans-serif}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--text);font-size:16px;line-height:1.55}
[hidden]{display:none!important}
a{color:var(--blue);text-underline-offset:3px}
button,input,select{font:inherit;color:inherit}
button{min-height:46px;border:1px solid var(--ink);padding:10px 20px;background:var(--paper);cursor:pointer;border-radius:0}
button:hover{background:#e9ebe2}
button:disabled{opacity:.45;cursor:default}
:focus-visible{outline:3px solid var(--blue);outline-offset:3px}
.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;top:-80px;left:20px;background:var(--ink);color:#fff;padding:12px;z-index:100}
.skip:focus{top:10px}
main{max-width:1180px;margin:0 auto;padding:40px 32px 24px}
main,[id],h2,[data-step]{scroll-margin-top:96px}

/* Intro */
.intro{max-width:900px;position:relative}
.eyebrow{font-size:11px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;margin:0}
.eyebrow a{color:inherit}
h1{font-family:var(--display);font-weight:400;font-size:clamp(44px,6.6vw,88px);line-height:1.04;letter-spacing:-.01em;margin:14px 0 18px;text-transform:uppercase}
h1 span{color:var(--amber)}
h1 .axis{color:var(--blue)}
.lede{font-size:18px;max-width:660px;margin:0 0 16px}
.note{display:inline-block;border:1px solid var(--ink);padding:4px 10px;font-size:12px;font-weight:600;margin:0}

/* Tabs */
.tabs{display:flex;border-bottom:1px solid var(--ink);margin-top:30px;gap:4px}
.tabs button{border:0;border-bottom:3px solid transparent;padding:12px 18px;background:transparent;font-weight:500}
.tabs button:hover{background:#ecede6}
.tabs [aria-selected=true]{border-bottom-color:var(--blue);color:var(--blue);font-weight:700}
section{padding-top:26px}

/* Lesson steps */
h2{font-size:clamp(25px,3vw,36px);line-height:1.15;font-weight:600;letter-spacing:-.035em;margin:8px 0 18px}
h2:focus{outline:none}
h2:focus-visible{outline:3px solid var(--blue);outline-offset:5px}
[data-step]{display:grid;grid-template-columns:minmax(0,1fr);grid-template-areas:"eyebrow" "title" "visual" "caption" "replay"}
[data-step]>.eyebrow{grid-area:eyebrow;color:var(--muted)}
[data-step]>h2{grid-area:title}
[data-step]>.visual{grid-area:visual}
[data-step]>.caption{grid-area:caption}
[data-step]>.replay{grid-area:replay;justify-self:start}
.visual{background:var(--panel);border:1px solid var(--rule);position:relative;overflow:hidden}
.visual svg{display:block;width:100%;height:auto;margin:0 auto}
.visual text{font-family:var(--text);fill:var(--ink);font-size:19px;font-weight:500;paint-order:stroke;stroke:var(--panel);stroke-width:4px;stroke-linejoin:round}
.visual text.xs{font-size:13px;font-weight:500}
.visual text.b{font-weight:700}
.visual text.blue{fill:var(--blue)}
.visual text.red{fill:var(--red)}
.visual text.amber{fill:var(--amber)}
.visual text.muted{fill:var(--muted)}
.readout{list-style:none;margin:0;padding:10px 12px;display:flex;flex-wrap:wrap;gap:6px 16px;border-top:1px solid var(--rule);background:var(--paper);font-size:13px}
.readout .head{flex-basis:100%;font-weight:700;font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.readout b{font-weight:600}
.readout .up{color:var(--amber);font-weight:700}
.readout .down{color:var(--blue);font-weight:700}
.caption{font-size:18px;max-width:760px;margin:16px 0}
.caption dfn{font-style:normal;font-weight:700}
.replay{font-size:14px;min-height:44px;margin-bottom:6px}
.step-nav{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--rule);padding-top:16px;margin-top:18px}
.step-nav button{min-width:120px;font-weight:600}
.step-nav [data-step-next]{background:var(--blue);color:#fff;border-color:var(--blue)}
.step-nav [data-step-next]:hover{background:#1a3ad1}
[data-step-progress]{font-size:14px;font-weight:600;white-space:nowrap}
.hint{font-size:13px;color:var(--muted)}

/* Clinical values */
.disclaimer{font-weight:700;border-left:4px solid var(--red);padding:8px 12px;background:#fff;max-width:760px}
.cv-top{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:28px;align-items:start;margin:20px 0 8px}
.cv-controls{display:grid;grid-template-columns:minmax(0,1fr);gap:12px}
.cv-controls button{justify-self:start}
label{display:block;font-weight:600}
label output{font-weight:400;color:var(--muted);margin-left:6px}
select{width:100%;min-height:46px;border:1px solid var(--ink);background:var(--paper);padding:8px;margin-top:6px}
input[type=range]{width:100%;accent-color:var(--blue);min-height:44px;margin:4px 0 0}
.state-summary{font-size:16px;min-height:26px;margin:10px 0;max-width:820px}
.model-note,.model-intro{font-size:13px;color:var(--muted);max-width:820px}
.model-note:empty{display:none}
.value-row{border-top:1px solid var(--rule);padding:18px 0;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.2fr);gap:6px 28px}
.value-row h3{font-size:17px;margin:0}
.value-row .reading{font-size:22px;font-weight:700;color:var(--blue)}
.value-row .status,.value-row .key,.value-row .compare{font-size:13px}
.value-row .direction{font-size:14px;font-weight:700;color:var(--red);min-height:20px}
.value-row .direction.quiet{color:var(--muted);font-weight:500}
.value-row .evidence{grid-column:1/-1;font-size:13px;background:#fff;border-left:3px solid var(--rule);padding:6px 10px}
.value-row .evidence:empty{display:none}
.value-row .citation{grid-column:1/-1;font-size:12px;color:var(--muted)}
.gauge{width:100%;height:auto;display:block}
.gauge text{font-family:var(--text);font-size:14px;font-weight:600;fill:var(--ink)}
.gauge text.end{font-weight:500;fill:var(--muted)}
.gauge .typical{stroke:var(--ink);stroke-width:7}
.gauge .limit{stroke:var(--ink);stroke-width:2}
.gauge .marker{stroke:var(--blue);stroke-width:5}
.gauge .cmp-marker{stroke:var(--ink);stroke-width:2.5;stroke-dasharray:4 3}
.gauge .track{stroke:var(--rule);stroke-width:3}
.gauge .band{fill:#d1d8fd}
#sources,.value-row .citation,.value-row .evidence,#state-source{overflow-wrap:anywhere}
#sources{padding-left:20px;font-size:13px}
#sources li{margin:10px 0}
.load-error{color:var(--red);font-weight:600}

/* Explore */
.explore-grid{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr);gap:28px;align-items:start}
fieldset{border:0;border-top:1px solid var(--rule);margin:0 0 10px;padding:8px 0 0;min-width:0}
legend{font-size:11px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);padding-right:8px}
.controls fieldset>label{margin-top:8px}
.choice-row,.choice-grid{display:flex;flex-wrap:wrap;gap:6px 8px}
.choice{display:flex;align-items:center;gap:8px;min-height:44px;padding:4px 12px 4px 8px;border:1px solid var(--rule);background:#fff;font-weight:500;cursor:pointer}
.choice input{width:20px;height:20px;margin:0;accent-color:var(--blue)}
.choice:has(input:checked){border-color:var(--blue);color:var(--blue);font-weight:700}
.choice:has(input:focus-visible){outline:3px solid var(--blue);outline-offset:2px}
.controls #reset{margin-top:12px}
.model-results{font-weight:600;padding:14px;border-left:3px solid var(--blue);background:#fff}
.chart-title{font-size:18px;margin:26px 0 10px}
.chart{max-width:760px}
summary{cursor:pointer;min-height:44px;display:flex;align-items:center;font-weight:600}
details p{max-width:820px;font-size:14px}

footer{border-top:1px solid var(--ink);margin-top:44px;padding-top:18px;font-size:12px}

@media(min-width:900px){
  [data-step]{grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);column-gap:36px;grid-template-rows:auto auto auto 1fr;grid-template-areas:"visual eyebrow" "visual title" "visual caption" "visual replay"}
  [data-step]>.eyebrow{margin-top:6px}
  [data-step]>.replay{align-self:start}
  .caption{margin-top:0}
  [data-step] .visual svg{max-height:calc(100vh - 230px);min-height:420px;width:auto;max-width:100%}
}
@media(max-width:899px){
  .explore-grid,.cv-top{grid-template-columns:minmax(0,1fr)}
}
@media(max-width:720px){
  .value-row{grid-template-columns:minmax(0,1fr)}
}
@media(max-width:620px){
  main{padding:24px 16px 20px}
  main,[id],h2,[data-step]{scroll-margin-top:80px}
  h1{font-size:40px}
  .lede{font-size:16px}
  .tabs{gap:0;margin-top:22px}
  .tabs button{font-size:13px;padding:10px 6px;flex:1}
  h2{font-size:24px;margin-bottom:12px}
  .caption{font-size:16px;margin:12px 0}
  .visual text.xs{font-size:14.5px}
  .step-nav{position:sticky;bottom:0;z-index:10;background:var(--paper);margin-top:8px;padding:10px 0 12px;box-shadow:0 -8px 14px var(--paper)}
  .step-nav button{min-width:0;padding:9px 14px}
  .hint{font-size:12px}
}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
/* Site top bar, matching the homepage's view A (Astra) bar. Scoped names so it cannot collide with lab.css or a lesson's CSS. */
.site-top{position:sticky;top:0;z-index:50;background:rgba(247,247,242,.96);border-bottom:1px solid #171916;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);font-family:'Space Grotesk',system-ui,-apple-system,'Segoe UI',sans-serif}
.site-top-in{max-width:1600px;margin:0 auto;padding-inline:clamp(22px,4vw,64px);height:78px;display:flex;align-items:center;gap:28px}
.site-brand{font-weight:700;font-size:27px;letter-spacing:-.08em;color:#171916;text-decoration:none;white-space:nowrap}
.site-brand span{color:#254dff;padding-inline:5px}
.site-nav{margin-left:auto;display:flex;align-items:center;gap:26px}
.site-nav a{color:#171916;text-decoration:none;font-size:13px;white-space:nowrap}
.site-nav a:hover{color:#254dff}
.site-nav a[aria-current]{color:#254dff;font-weight:600;text-decoration:underline;text-decoration-thickness:2px;text-underline-offset:6px}
.site-top a:focus-visible{outline:3px solid #254dff;outline-offset:3px}
@media(max-width:850px){.site-top-in{height:70px}.site-nav{gap:17px}.site-nav a{font-size:12px}}
@media(max-width:620px){.site-top-in{height:66px;gap:15px}.site-brand{font-size:24px}.site-nav{gap:18px}.site-nav a{display:none}.site-nav a.site-nav-home,.site-nav a.site-nav-lab{display:block}}
@media print{.site-top{position:static}}