/* GRAVITY: shared tokens and document styles */
:root{
  --ember-rgb:214,154,88;
  --page-background:#060F1A;--page-background-deep:#05090F;--flesh-1:#0D141C;--flesh-2:#14202C;
  --ember:#D69A58;--ember-ink:#EFC084;--descent-1:#01050A;--descent-2:#D68A34;
  --ink:#F2EADD;--muted:#ABA093;--void:#01050A;--surface-base:#060F1A;
  --rule:rgba(var(--ember-rgb),.34);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:Antonio,'Archivo Narrow',Oswald,system-ui,sans-serif;font-weight:700;letter-spacing:0;color:var(--ink);background:var(--page-background-deep)}
a:focus-visible,button:focus-visible,input:focus-visible{outline:2px solid var(--ember-ink);outline-offset:2px}
img,svg{display:block;max-width:100%}

/* header: fixed, transparent forever */
header{position:fixed;inset:0 0 auto 0;height:7.5vh;min-height:52px;z-index:1001;background:var(--page-background-deep);display:flex;align-items:center;gap:2vw;padding:0 2.6vw;
  --link:var(--ink);--link-hover:var(--ember-ink);--brand:var(--ink)}
header.on-void{--link:var(--muted);--link-hover:var(--ember);--brand:var(--ink);background:transparent}
.wordmark{display:flex;align-items:center;gap:.8vw;text-decoration:none;color:var(--brand);font-size:1.14vw;text-transform:uppercase;transition:color .3s ease-in-out}
.wordmark svg{width:1.4vw;height:1.4vw}
nav{display:flex;gap:1.75vw;margin-left:auto}
nav a{font-size:.9rem;color:var(--link);text-decoration:none;transition:color .3s ease-in-out;white-space:nowrap}
nav a:hover{color:var(--link-hover)}
nav a[aria-current]{color:var(--ember)}
.menu-toggle{display:none}

/* document pages */
main.doc{padding:calc(7.5vh + clamp(3rem,6vw,5rem)) clamp(1.25rem,6vw,5rem) clamp(4rem,8vw,7rem)}
.doc .inner{max-width:68ch;margin:0 auto}
.byline{font-size:.85rem;color:var(--muted);font-weight:400;margin-bottom:2.5rem;display:flex;gap:.8rem;align-items:center;flex-wrap:wrap}
.byline svg{width:.9rem;height:.9rem;flex:none}
.doc h1{font-size:clamp(2.8rem,6.5vw,5.4rem);line-height:1.02;text-transform:uppercase;margin-bottom:1.2rem}
.standfirst{font-weight:400;font-size:clamp(1.25rem,1vw+1rem,1.6rem);line-height:1.5;color:var(--muted);margin-bottom:3rem}
.doc h2{font-size:clamp(1.6rem,2.6vw,2.2rem);margin:3rem 0 .6rem;line-height:1.2}
.doc h3{font-size:clamp(1.15rem,1.6vw,1.35rem);margin:1.8rem 0 .3rem}
.doc p,.doc li{font-weight:400;font-size:clamp(1rem,.5vw+.9rem,1.125rem);line-height:1.65;margin-bottom:1rem}
.doc ul,.doc ol{padding-left:1.3rem;margin-bottom:1rem}
.doc li{margin-bottom:.4rem}
.doc strong{font-weight:700}
.doc a{color:var(--ember-ink)}
figure{margin:2.6rem 0}
figcaption{font-size:.85rem;color:var(--muted);font-weight:400;margin-top:.7rem;line-height:1.5}
table{width:100%;border-collapse:collapse;margin:2rem 0;font-weight:400;font-size:.95rem;line-height:1.45}
th,td{border:1px solid var(--rule);padding:.6rem .7rem;text-align:left;vertical-align:top}
th{font-weight:700;background:var(--flesh-2)}
.callout{border:1px solid var(--rule);background:var(--flesh-1);padding:1.2rem 1.4rem;margin:2rem 0}
.callout p:last-child{margin:0}
.next{margin-top:4rem;padding-top:1.5rem;border-top:1px solid var(--rule);display:flex;justify-content:space-between;gap:2rem;flex-wrap:wrap}
.next a{text-decoration:none;color:var(--ember-ink);font-size:1.1rem;display:inline-flex;align-items:center;gap:.5rem}
.next a:hover{color:var(--ink)}
.next svg{width:1.1rem;height:1.1rem}
.doc footer{margin-top:4rem;padding-top:1.2rem;border-top:1px solid var(--rule);font-size:.8rem;color:var(--muted);font-weight:400;line-height:1.5}
.doc footer .disc{display:flex;gap:.8rem;align-items:flex-start}
.doc footer svg{width:.7rem;height:.7rem;flex:none;margin-top:.3rem}

/* buttons */
.btn{display:inline-block;background:var(--ember);color:var(--surface-base);text-transform:uppercase;text-decoration:none;font-size:1.05rem;padding:.8rem 2.6rem;border:0;cursor:pointer;font-family:inherit;font-weight:700}
.btn:hover{background:var(--ember-ink)}
.btn.ghost{background:transparent;color:var(--ink);border:1px solid var(--rule)}
.btn.ghost:hover{background:var(--ink);color:var(--surface-base)}
.btn[disabled]{opacity:.4;cursor:default}

/* quiz */
.quiz{border:1px solid var(--rule);background:var(--flesh-1);margin:2.5rem 0}
.quiz .head{display:flex;justify-content:space-between;align-items:center;padding:1rem 1.4rem;border-bottom:1px solid var(--rule);font-size:.85rem;color:var(--muted);font-weight:400}
.quiz .bar{height:3px;background:var(--flesh-2)}
.quiz .bar i{display:block;height:100%;background:var(--ember);width:0;transition:width .4s ease-in-out}
.quiz .q{padding:1.6rem 1.4rem}
.quiz .q>p{font-weight:700;font-size:clamp(1.2rem,2vw,1.6rem);line-height:1.3;margin-bottom:1.2rem}
.quiz .opts{display:grid;gap:.6rem}
.quiz .opts button{text-align:left;font:inherit;font-weight:400;font-size:1rem;padding:.9rem 1rem;background:var(--surface-base);border:1px solid var(--rule);cursor:pointer;color:var(--ink);line-height:1.4}
.quiz .opts button:hover{background:var(--flesh-2)}
.quiz .result{padding:1.8rem 1.4rem}
.quiz .result p{font-weight:400;font-size:1rem;line-height:1.6}
.quiz .result h3{margin-top:0;font-size:clamp(1.4rem,2.4vw,2rem);line-height:1.2}
.quiz .result .tier{color:var(--ember-ink);font-size:.85rem;text-transform:uppercase;margin-bottom:.4rem}
.quiz form{margin-top:1.6rem;padding-top:1.4rem;border-top:1px solid var(--rule)}
.quiz label{display:block;font-size:.85rem;color:var(--muted);font-weight:400;margin-bottom:.5rem}
.quiz .row{display:flex;gap:.6rem;flex-wrap:wrap}
.quiz input[type=email]{flex:1;min-width:14rem;font:inherit;font-weight:400;font-size:1rem;padding:.75rem .9rem;border:1px solid var(--rule);background:var(--surface-base);color:var(--ink)}
.quiz .fine{font-size:.78rem;color:var(--muted);font-weight:400;margin-top:.7rem;line-height:1.45}
.quiz .ok{color:var(--ember-ink);font-weight:700}
.quiz .restart{background:none;border:0;font:inherit;font-size:.85rem;color:var(--muted);cursor:pointer;text-decoration:underline;margin-top:1rem;font-weight:400}

@media (max-width:1200px){
  header{height:auto;padding:1.2rem 5vw;flex-wrap:wrap;background:var(--page-background-deep);border-bottom:1px solid var(--rule)}
  header.on-void{background:var(--void);border-color:var(--ember-ink)}
  .wordmark{font-size:1.2rem}.wordmark svg{width:1.2rem;height:1.2rem}
  .menu-toggle{display:block;background:none;border:1px solid currentColor;color:var(--link);font:inherit;font-size:.85rem;padding:.4rem .8rem;cursor:pointer}
  nav{display:none;width:100%;flex-direction:column;gap:.9rem;padding-top:1.2rem}
  nav.open{display:flex}
  nav a{font-size:1rem}
  main.doc{padding-top:6.5rem}
}
@media (prefers-reduced-motion:reduce){*{animation:none !important;transition:none !important}html{scroll-behavior:auto}}

/* full-bleed anatomy plates */
figure.plate{margin:2.8rem 0}
figure.plate img{width:100%;height:auto;border:1px solid var(--rule)}

/* tables scroll inside themselves on narrow screens */
.tablewrap{overflow-x:auto;margin:2rem 0;-webkit-overflow-scrolling:touch}
.tablewrap table{margin:0;min-width:32rem}

/* ============ light, motion and seamless plates ============ */

/* a soft light on the guide pages so the ground is never flat */
main.doc::before{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:
    radial-gradient(120% 62% at 50% -14%, rgba(var(--ember-rgb),.13) 0%, rgba(var(--ember-rgb),0) 62%),
    radial-gradient(80% 55% at 8% 106%, rgba(120,168,214,.055) 0%, rgba(0,0,0,0) 60%);
}

/* plates dissolve into the page instead of sitting in a box */
figure.plate{
  margin:3.2rem 0;
  /* break out of the text column, but never past the viewport.
     100% is the text column; 92vw leaves room for the scrollbar. */
  --bo:max(0px, min(10rem, calc((92vw - 100%) / 2)));
  width:calc(100% + 2 * var(--bo));
  margin-left:calc(-1 * var(--bo));
}
figure.plate img{
  width:100%;height:auto;border:0;display:block;
  -webkit-mask-image:radial-gradient(116% 112% at 50% 50%, #000 60%, rgba(0,0,0,0) 100%);
          mask-image:radial-gradient(116% 112% at 50% 50%, #000 60%, rgba(0,0,0,0) 100%);
  transition:transform 1.1s cubic-bezier(.22,.61,.36,1), filter 1.1s cubic-bezier(.22,.61,.36,1);
}
@media (hover:hover){
  figure.plate:hover img{transform:scale(1.014);filter:brightness(1.07) saturate(1.04)}
}
figure.plate figcaption{max-width:62ch;margin-left:auto;margin-right:auto;text-align:center}

/* scroll reveal */
.reveal{opacity:0;transform:translateY(15px);
  transition:opacity .8s cubic-bezier(.22,.61,.36,1), transform .8s cubic-bezier(.22,.61,.36,1)}
.reveal.in{opacity:1;transform:none}
.reveal.d1{transition-delay:.06s}.reveal.d2{transition-delay:.12s}.reveal.d3{transition-delay:.18s}

/* a gold rule that draws itself under each heading */
.doc h2{position:relative;padding-top:1.15rem}
.doc h2::before{content:"";position:absolute;top:0;left:0;height:1px;width:0;
  background:linear-gradient(90deg,var(--ember),rgba(var(--ember-rgb),0));
  transition:width 1s cubic-bezier(.22,.61,.36,1) .12s}
.doc h2.in::before{width:5.5rem}

/* links: an underline that grows rather than a static one */
.doc a:not(.btn):not(.wordmark):not(.ask-btn){
  text-decoration:none;
  background-image:linear-gradient(currentColor,currentColor);
  background-size:0% 1px;background-repeat:no-repeat;background-position:0 100%;
  transition:background-size .4s cubic-bezier(.22,.61,.36,1), color .3s}
.doc a:not(.btn):not(.wordmark):not(.ask-btn):hover{background-size:100% 1px;color:var(--ember-ink)}

/* the header settles onto glass once you leave the top */
header{transition:background .45s ease, border-color .45s ease, backdrop-filter .45s ease}
header.scrolled{background:rgba(5,9,15,.78);backdrop-filter:blur(12px) saturate(1.2);
  -webkit-backdrop-filter:blur(12px) saturate(1.2);border-bottom:1px solid var(--rule)}

/* tables come alive on hover */
.doc tbody tr{transition:background .3s ease}
.doc tbody tr:hover{background:rgba(var(--ember-rgb),.07)}
.doc thead th{background:var(--flesh-2);letter-spacing:.02em}

/* callouts get a gold edge rather than a full box */
.callout{border:0;border-left:2px solid var(--ember);background:linear-gradient(90deg,rgba(var(--ember-rgb),.07),rgba(var(--ember-rgb),0) 70%);padding:1.3rem 1.5rem}

@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  .doc h2::before{width:5.5rem;transition:none}
  figure.plate img{transition:none}
}

/* ============ animated sequences: one frame that changes ============ */
.sequence .seq-stage{
  position:relative;overflow:hidden;margin:0 auto;
  aspect-ratio:var(--arw) / var(--arh);
  /* a single portrait panel would be absurdly tall at column width,
     so size it by viewport height and never exceed the column */
  width:min(100%, max(320px, calc(78vh * var(--arw) / var(--arh))));
}
.sequence .seq-stage img{
  position:absolute;inset:0;width:100%;height:100%;object-fit:contain;
  opacity:0;transition:opacity 1.15s cubic-bezier(.4,0,.2,1)}
.sequence .seq-stage img.on{opacity:1}
.seq-steps{display:flex;margin:1.2rem auto 0;border-top:1px solid var(--rule);
  width:min(100%, max(27rem, calc(78vh * var(--arw) / var(--arh))));}
.seq-steps button{
  flex:1;background:none;border:0;border-top:2px solid transparent;margin-top:-1px;
  color:var(--muted);font:inherit;font-weight:700;font-size:.72rem;letter-spacing:.05em;
  text-transform:uppercase;padding:.8rem .25rem;cursor:pointer;white-space:nowrap;
  transition:color .3s ease, border-color .5s cubic-bezier(.22,.61,.36,1)}
.seq-steps button:hover{color:var(--ink)}
.seq-steps button.on{color:var(--ember);border-top-color:var(--ember)}
.sequence figcaption{margin-top:1rem}
.sequence .seq-steps{max-width:100%}

@media (prefers-reduced-motion:reduce){
  /* no motion: lay the frames out side by side, which is the original plate */
  .sequence .seq-stage{display:flex;aspect-ratio:auto;height:auto;width:100%}
  .sequence .seq-stage img{position:static;opacity:1;flex:1 1 0;width:auto;height:auto;min-width:0}
  .seq-steps{width:100%}
  .seq-steps button{cursor:default;color:var(--muted);border-top-color:transparent}
  .seq-steps button.on{color:var(--muted);border-top-color:transparent}
}

/* the two boards, shown as a matched pair */
.seals{display:grid;grid-template-columns:1fr 1fr;gap:clamp(1.5rem,4vw,3.4rem);
  align-items:start;margin:2.8rem 0 3rem}
.seals figure{margin:0;text-align:center}
.seals img{width:min(100%,230px);height:auto;margin:0 auto;
  filter:drop-shadow(0 0 26px rgba(var(--ember-rgb),.15));
  transition:transform .9s cubic-bezier(.22,.61,.36,1), filter .9s cubic-bezier(.22,.61,.36,1)}
@media (hover:hover){
  .seals figure:hover img{transform:translateY(-5px) scale(1.03);
    filter:drop-shadow(0 0 34px rgba(var(--ember-rgb),.32))}
}
.seals figcaption{margin-top:1rem;font-size:.82rem;line-height:1.5;color:var(--muted);font-weight:400}
.seals b{display:block;color:var(--ink);font-size:1.02rem;font-weight:700;margin-bottom:.35rem}
@media (max-width:560px){.seals{grid-template-columns:1fr;gap:2.4rem}}
@media (prefers-reduced-motion:reduce){.seals img{transition:none}}

/* ============ making long lists readable ============ */

/* a thin gold bar so the length of the page is knowable */
.progress{position:fixed;top:0;left:0;right:0;height:2px;z-index:1002;pointer-events:none;background:transparent}
.progress i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--ember),var(--ember-ink))}

/* numbered lists become a scannable checklist rather than a paragraph of lines */
.doc ol{list-style:none;padding-left:0;counter-reset:q;margin:1.6rem 0 2rem}
.doc ol > li{
  counter-increment:q;display:grid;grid-template-columns:2.5rem 1fr;gap:.9rem;
  align-items:baseline;padding:.95rem 0;margin:0;
  border-bottom:1px solid rgba(var(--ember-rgb),.15)}
.doc ol > li:first-child{border-top:1px solid rgba(var(--ember-rgb),.15)}
.doc ol > li::before{
  content:counter(q,decimal-leading-zero);
  font-size:.76rem;font-weight:700;color:var(--ember);letter-spacing:.07em;
  font-variant-numeric:tabular-nums}

/* bullets become a gold rule with room to breathe */
.doc ul{list-style:none;padding-left:0;margin:1.4rem 0 2rem}
.doc ul > li{position:relative;padding:.6rem 0 .6rem 1.75rem;margin:0}
.doc ul > li::before{content:"";position:absolute;left:0;top:1.5em;
  width:.8rem;height:1px;background:var(--ember);opacity:.85}
.doc ul ul{margin:.5rem 0 0}

@media (prefers-reduced-motion:reduce){.progress{display:none}}

/* ============ what-changes: responsive table, evidence, ask ============ */
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}

/* three columns on desktop; genuine stacked cards on narrow screens */
@media (max-width:720px){
  .tablewrap .rt-table,.rt-table{min-width:0}
  .rt-table thead{position:absolute;width:1px;height:1px;margin:-1px;
    overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
  .tablewrap:has(.rt-table){overflow-x:visible}
  .rt-table,.rt-table tbody,.rt-table tr,.rt-table td{display:block;width:100%}
  .rt-table tr{border:1px solid var(--rule);padding:1.15rem 1.25rem;margin:0 0 1rem}
  .rt-table td{border:0;padding:.5rem 0;font-size:1rem;line-height:1.6}
  .rt-table td+td{border-top:1px solid rgba(var(--ember-rgb),.14);padding-top:.85rem}
  .rt-table td::before{content:attr(data-label);display:block;font-size:.68rem;
    letter-spacing:.12em;text-transform:uppercase;color:var(--ember);
    margin-bottom:.35rem;font-weight:700}
}

/* the question link */
.ask{margin:3.4rem 0 0;padding:1.7rem 1.8rem;border:1px solid var(--rule);
  background:linear-gradient(120deg,rgba(var(--ember-rgb),.06),rgba(var(--ember-rgb),0) 72%)}
.ask-lead{font-size:1.08rem;font-weight:700;color:var(--ink);margin:0 0 .35rem;line-height:1.3}
.ask-body{font-size:.9rem;color:var(--muted);font-weight:400;margin:0 0 1.15rem;line-height:1.55}
.doc a.ask-btn,.ask-btn{display:inline-flex;align-items:center;gap:.5rem;background:var(--ember);
  color:var(--surface-base);text-decoration:none;font-weight:700;font-size:.9rem;
  letter-spacing:.05em;text-transform:uppercase;padding:.78rem 1.7rem;
  transition:background .3s ease}
.doc a.ask-btn:hover,.doc a.ask-btn:focus-visible,.ask-btn:hover,.ask-btn:focus-visible{background:var(--ember-ink);color:var(--surface-base)}

/* selected evidence */
.evidence{margin-top:4rem;padding-top:2.2rem;border-top:1px solid var(--rule);counter-reset:q}
.evidence h2{font-size:clamp(1.3rem,2.1vw,1.6rem);margin-top:0}
.evidence h2::before{width:5.5rem}
.ev-note{font-size:.85rem;color:var(--muted);font-weight:400;line-height:1.55;
  max-width:64ch;margin:0 0 1.7rem}
.evidence h3{font-size:.72rem;letter-spacing:.13em;text-transform:uppercase;
  color:var(--ember);margin:2rem 0 .3rem;font-weight:700}
.doc .evidence ol.refs{counter-reset:none;margin:0}
.doc .evidence ol.refs > li{grid-template-columns:2.1rem 1fr;gap:.8rem;
  padding:.65rem 0;font-size:.87rem;line-height:1.5;font-weight:400}
.doc .evidence ol.refs > li::before{font-size:.68rem}
.doc .evidence ol.refs > li:first-child{border-top:0}
.doc .evidence ol.refs a{color:var(--ink)}
.doc .evidence ol.refs a:hover{color:var(--ember-ink)}
.doc .evidence ol.refs span{display:block;color:var(--muted);font-size:.78rem;
  margin-top:.25rem;line-height:1.45}

/* ============ what-changes revision, 2026-09-02 ============ */

/* evidence: citation and study type share the content column, number stays in the first column */
.doc .evidence ol.refs > li > span{grid-column:2;margin-top:.25rem}
.doc .evidence ol.refs > li > .reference-content{grid-column:2;min-width:0}
.doc .evidence ol.refs > li > .reference-content > span{display:block;color:var(--muted);font-size:.78rem;margin-top:.25rem;line-height:1.45}

/* evidence: collapsed by default behind a native disclosure */
.evidence details.ev{border:0}
.evidence summary{display:grid;grid-template-columns:1fr auto 1.4rem;align-items:center;gap:1rem;
  cursor:pointer;list-style:none;padding:.4rem 0;margin:0}
.evidence summary::-webkit-details-marker{display:none}
.evidence summary::marker{content:""}
.evidence summary h2{margin:0}
.evidence summary h2::before{width:5.5rem}
.evidence .ev-count{font-size:.72rem;letter-spacing:.13em;text-transform:uppercase;color:var(--muted);font-weight:700;white-space:nowrap}
.evidence .ev-chev{width:1.4rem;height:1.4rem;position:relative}
.evidence .ev-chev::before{content:"";position:absolute;left:.35rem;top:.3rem;width:.55rem;height:.55rem;
  border-right:1px solid var(--ember);border-bottom:1px solid var(--ember);
  transform:rotate(45deg);transform-origin:center;transition:transform .35s cubic-bezier(.22,.61,.36,1)}
.evidence details[open] > summary .ev-chev::before{transform:rotate(-135deg) translate(-.1rem,-.1rem)}
.evidence summary:hover h2,.evidence summary:hover .ev-count{color:var(--ember-ink)}
.evidence summary:focus-visible{outline:2px solid var(--ember-ink);outline-offset:4px}
.evidence .ev-body{padding-top:1.4rem}
@media (prefers-reduced-motion:reduce){.evidence .ev-chev::before{transition:none}}

/* treatment table breaks out of the text column on wide screens, centred */
@media (min-width:900px){
  .doc .tablewrap{width:min(56rem,calc(100vw - 4rem));max-width:none;margin-left:50%;translate:-50% 0}
  .doc .tablewrap .rt-table th:first-child,.doc .tablewrap .rt-table td:first-child{width:24%}
}