/* ============================================================================
   CENTRALUX — "The Instrument"
   One shared stylesheet for all six pages. No framework, no build step.
   Tokens are documented in design-tokens.md.
   ========================================================================== */

/* --- 1. Tokens ----------------------------------------------------------- */
:root{
  --ink:#0b0d0f;
  --ink-2:#0e1113;
  --surface:#12161a;
  --surface-2:#171c20;

  --line:rgba(255,255,255,.085);
  --line-2:rgba(255,255,255,.16);

  --gold:#E3B23E;
  --gold-dim:rgba(227,178,62,.40);
  --gold-faint:rgba(227,178,62,.10);

  --text:#e9ecee;
  --muted:#a2abb1;
  --faint:#7b858b;

  --sans:"Space Grotesk",-apple-system,BlinkMacSystemFont,"Segoe UI",Helvetica,Arial,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --t-display:clamp(2.35rem,6.2vw,4.05rem);
  --t-h2:clamp(1.55rem,3.1vw,2.15rem);
  --t-h3:clamp(1.1rem,1.6vw,1.3rem);
  --t-body:1.0625rem;
  --t-small:.9375rem;
  --t-label:.6875rem;

  --r:2px;
  --ease:cubic-bezier(.2,0,0,1);
  --dur:180ms;

  --wrap:1180px;
  --gutter:clamp(20px,4.4vw,52px);
  --section:clamp(60px,7.6vw,108px);
}

/* --- 2. Reset ------------------------------------------------------------ */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
[id]{scroll-margin-top:96px}
body,h1,h2,h3,h4,p,ul,ol,dl,dd,dt,figure,blockquote{margin:0;padding:0}
ul,ol{list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit}

html,body{overflow-x:hidden}

body{
  background:var(--ink);
  color:var(--text);
  font-family:var(--sans);
  font-size:var(--t-body);
  line-height:1.72;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

a{color:var(--gold);text-decoration:none}
a:hover{text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
:focus-visible{outline:2px solid var(--gold);outline-offset:3px}

::selection{background:var(--gold);color:var(--ink)}

/* --- 3. Layout primitives ------------------------------------------------ */
.wrap{width:100%;max-width:var(--wrap);margin:0 auto;padding-inline:var(--gutter)}
.section{padding-block:var(--section)}
.section--band{background:var(--ink-2);border-block:1px solid var(--line)}
.measure{max-width:68ch}
.measure-wide{max-width:82ch}
.stack>*+*{margin-top:20px}
.skip{position:absolute;left:-9999px;top:0}
.skip:focus{left:12px;top:12px;z-index:99;background:var(--gold);color:var(--ink);padding:10px 16px;font-family:var(--mono);font-size:var(--t-label);letter-spacing:.14em;text-transform:uppercase}

/* --- 4. Mono label system ------------------------------------------------ */
.lab{
  font-family:var(--mono);
  font-size:var(--t-label);
  letter-spacing:.15em;
  text-transform:uppercase;
  font-weight:500;
  color:var(--faint);
  line-height:1.5;
}
.lab--gold{color:var(--gold)}
.lab--text{color:var(--text)}

/* Section header: § index + title + hairline to the edge */
.shead{display:flex;align-items:baseline;gap:16px;margin-bottom:36px}
.shead__idx{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.15em;color:var(--gold);white-space:nowrap;padding-top:6px}
.shead__t{font-size:var(--t-h2);font-weight:500;line-height:1.16;letter-spacing:-.015em}
.shead__rule{flex:1 1 auto;height:1px;background:var(--line);min-width:12px;transform:translateY(-6px)}

h1,h2,h3,h4{font-weight:500;letter-spacing:-.015em;line-height:1.18}
h3{font-size:var(--t-h3)}
p{color:var(--muted)}
p strong,li strong{color:var(--text);font-weight:500}

/* --- 5. Header ----------------------------------------------------------- */
.hdr{
  position:sticky;top:0;z-index:40;
  background:rgba(11,13,15,.88);
  backdrop-filter:saturate(140%) blur(10px);
  border-bottom:1px solid var(--line);
}
.hdr__in{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:66px}
.brand{display:inline-flex;align-items:center;gap:11px;color:var(--gold);text-decoration:none}
.brand:hover{text-decoration:none}
.brand svg{width:23px;height:23px;flex:none}
.brand__wm{
  font-family:var(--sans);font-weight:700;font-size:.95rem;
  letter-spacing:.24em;color:var(--text);text-transform:uppercase;
}
.nav{display:flex;align-items:center;gap:clamp(14px,2.4vw,30px)}
.nav a{
  font-family:var(--mono);font-size:var(--t-label);letter-spacing:.14em;
  text-transform:uppercase;color:var(--muted);text-decoration:none;
  padding-block:4px;border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.nav a:hover{color:var(--text);border-bottom-color:var(--gold);text-decoration:none}
.nav a[aria-current="page"]{color:var(--gold);border-bottom-color:var(--gold-dim)}
.hdr .btn{padding:9px 15px}

/* --- 6. Buttons ---------------------------------------------------------- */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--mono);font-size:var(--t-label);letter-spacing:.15em;
  text-transform:uppercase;font-weight:500;
  padding:14px 22px;border-radius:var(--r);
  border:1px solid var(--gold);color:var(--gold);background:transparent;
  text-decoration:none;white-space:nowrap;
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.btn:hover{background:var(--gold);color:var(--ink);text-decoration:none}
.btn--ghost{border-color:var(--line-2);color:var(--text)}
.btn--ghost:hover{background:transparent;border-color:var(--gold);color:var(--gold)}
.btn__arrow{font-size:.9em;transform:translateY(-1px)}
.btnrow{display:flex;flex-wrap:wrap;gap:12px;align-items:center}

/* --- 7. Hero ------------------------------------------------------------- */
.hero{position:relative;padding-block:clamp(56px,8vw,104px) clamp(36px,5vw,56px);overflow:hidden}
.hero::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(255,255,255,.03) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.03) 1px,transparent 1px);
  background-size:46px 46px;
  -webkit-mask-image:radial-gradient(135% 96% at 14% 6%,#000 0%,rgba(0,0,0,.5) 40%,transparent 78%);
  mask-image:radial-gradient(135% 96% at 14% 6%,#000 0%,rgba(0,0,0,.5) 40%,transparent 78%);
}
.hero__in{position:relative}
.hero__eyebrow{display:flex;flex-wrap:wrap;gap:8px 18px;align-items:center;margin-bottom:26px}
.hero h1{
  font-size:var(--t-display);font-weight:500;line-height:1.04;letter-spacing:-.03em;
  max-width:15ch;overflow-wrap:break-word;
}
.hero h1 em{font-style:normal;color:var(--gold)}
.hero__sub{margin-top:24px;max-width:56ch;font-size:clamp(1.05rem,1.5vw,1.19rem);line-height:1.62;color:var(--muted)}
.hero__cta{margin-top:34px}

/* hero spec strip */
.specstrip{
  margin-top:44px;border-top:1px solid var(--line);
  display:grid;grid-template-columns:repeat(3,minmax(0,1fr));
}
.specstrip>div{padding:18px 20px 0 0;border-right:1px solid var(--line)}
.specstrip>div:last-child{border-right:0}
.specstrip dt{margin-bottom:6px}
.specstrip dd{margin:0;font-size:var(--t-small);color:var(--text);line-height:1.5}

/* --- 8. The instrument panel (FIG. 01) ----------------------------------- */
.panel{
  position:relative;background:var(--surface);
  border:1px solid var(--line-2);border-radius:var(--r);
}
.panel::before,.panel::after{
  content:"";position:absolute;width:9px;height:9px;pointer-events:none;
  border-color:var(--gold-dim);border-style:solid;
}
.panel::before{top:-1px;left:-1px;border-width:1px 0 0 1px}
.panel::after{bottom:-1px;right:-1px;border-width:0 1px 1px 0}

.panel__head{
  display:flex;flex-wrap:wrap;gap:8px 18px;align-items:center;justify-content:space-between;
  padding:13px 18px;border-bottom:1px solid var(--line);
  background:linear-gradient(180deg,rgba(255,255,255,.02),transparent);
}
.panel__body{padding:22px 18px}
.panel figcaption{
  padding:13px 18px;border-top:1px solid var(--line);
  font-family:var(--mono);font-size:.6875rem;line-height:1.6;color:var(--faint);letter-spacing:.02em;
}

/* channel strip */
.channels{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:1px;background:var(--line)}
.ch{background:var(--surface-2);padding:16px 14px 15px;position:relative;min-width:0}
.ch__top{display:flex;align-items:center;gap:9px;margin-bottom:11px}
.ch__id{font-family:var(--mono);font-size:.625rem;letter-spacing:.14em;color:var(--faint)}
.led{
  width:7px;height:7px;border-radius:1px;flex:none;margin-left:auto;
  background:rgba(255,255,255,.14);
  box-shadow:0 0 0 0 transparent;
}
.ch__name{font-family:var(--sans);font-weight:500;font-size:.9375rem;letter-spacing:-.005em;color:var(--text);line-height:1.3}
.ch__state{font-family:var(--mono);font-size:.6875rem;line-height:1.55;color:var(--faint);margin-top:7px;letter-spacing:.01em}
.ch__seg{display:flex;gap:3px;margin-top:13px}
.ch__seg i{display:block;height:3px;flex:1;background:rgba(255,255,255,.07);border-radius:1px}
.ch__seg i.on{background:rgba(227,178,62,.72)}

/* conduit rail */
.rail{position:relative;height:1px;background:var(--line);margin:22px 2px 0}
.rail__pulse{
  position:absolute;top:-2px;left:0;width:5px;height:5px;border-radius:1px;
  background:var(--gold);
  animation:railrun 10s linear infinite;
}
.rail__tick{position:absolute;top:-3px;width:1px;height:7px;background:var(--line-2)}

/* provenance trace */
.trace{margin-top:26px;border:1px solid var(--line);border-radius:var(--r)}
.trace__head{
  padding:10px 14px;border-bottom:1px solid var(--line);
  display:flex;flex-wrap:wrap;gap:6px 14px;justify-content:space-between;align-items:baseline;
}
.trace ol{font-family:var(--mono);font-size:.6875rem;letter-spacing:.02em}
.trace li{
  display:grid;grid-template-columns:44px minmax(0,240px) minmax(0,1fr) auto;
  gap:10px;align-items:center;
  padding:9px 14px;border-bottom:1px solid var(--line);color:var(--muted);
}
.trace li:last-child{border-bottom:0}
.trace .t{color:var(--gold);font-variant-numeric:tabular-nums}
.trace .ev{color:var(--text)}
.trace .sink{color:var(--faint)}
.trace .st{color:var(--gold-dim);text-align:right;white-space:nowrap}
.trace .st--gate{color:var(--gold)}

@keyframes railrun{
  0%{left:0;opacity:0}
  6%{opacity:1}
  94%{opacity:1}
  100%{left:calc(100% - 5px);opacity:0}
}
@keyframes ledseq{
  0%,100%{background:rgba(255,255,255,.14);box-shadow:0 0 0 0 transparent}
  4%,18%{background:var(--gold);box-shadow:0 0 0 3px var(--gold-faint)}
  24%,96%{background:var(--gold-dim);box-shadow:0 0 0 0 transparent}
}
.ch:nth-child(1) .led{animation:ledseq 10s var(--ease) infinite -0.0s}
.ch:nth-child(2) .led{animation:ledseq 10s var(--ease) infinite -8.0s}
.ch:nth-child(3) .led{animation:ledseq 10s var(--ease) infinite -6.0s}
.ch:nth-child(4) .led{animation:ledseq 10s var(--ease) infinite -4.0s}
.ch:nth-child(5) .led{animation:ledseq 10s var(--ease) infinite -2.0s}

/* --- 9. Figures (static SVG diagrams) ------------------------------------ */
.fig{border:1px solid var(--line);border-radius:var(--r);background:var(--ink-2)}
.fig__head{padding:12px 16px;border-bottom:1px solid var(--line);display:flex;flex-wrap:wrap;gap:6px 16px;justify-content:space-between}
.fig__body{padding:22px 16px}
.fig svg{width:100%;height:auto}
.fig figcaption{padding:12px 16px;border-top:1px solid var(--line);font-family:var(--mono);font-size:.6875rem;line-height:1.6;color:var(--faint)}

/* convergence bus (FIG. 02) — pure CSS, no image */
.bus{display:grid;grid-template-columns:minmax(0,240px) 1px minmax(0,1fr);align-items:center;max-width:760px;margin-inline:auto}
.bus__in li{
  position:relative;text-align:right;padding:9px 26px 9px 0;
  font-family:var(--mono);font-size:.75rem;letter-spacing:.02em;color:var(--muted);line-height:1.5;
}
.bus__in li::after{
  content:"";position:absolute;right:0;top:50%;width:18px;height:1px;background:var(--gold-dim);
}
.bus__spine{width:1px;height:100%;background:var(--gold-dim);justify-self:center}
.bus__out{position:relative;padding:0 0 0 30px}
.bus__out::before{content:"";position:absolute;left:0;top:50%;width:20px;height:1px;background:var(--gold-dim)}
.bus__out-t{font-family:var(--sans);font-size:var(--t-h3);font-weight:500;color:var(--text);margin:8px 0 10px;line-height:1.25}
.bus__out p{font-size:var(--t-small);line-height:1.62}
@media (max-width:620px){
  .bus{grid-template-columns:1fr}
  .bus__spine{display:none}
  .bus__in{border-left:1px solid var(--gold-dim);padding-left:0}
  .bus__in li{text-align:left;padding:8px 0 8px 22px}
  .bus__in li::after{right:auto;left:0;width:14px}
  .bus__in li::before{display:none}
  .bus__out{padding:24px 0 0;margin-top:18px;border-top:1px solid var(--line)}
  .bus__out::before{display:none}
}

/* --- 10. Spec tables ----------------------------------------------------- */
.spec{border-top:1px solid var(--line)}
.spec__row{
  display:grid;grid-template-columns:minmax(0,180px) minmax(0,1fr);
  gap:8px 28px;padding:14px 0;border-bottom:1px solid var(--line);
}
.spec dt{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.15em;text-transform:uppercase;color:var(--faint);padding-top:3px}
.spec dd{margin:0;font-size:var(--t-small);color:var(--text);line-height:1.62;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}
.spec dd .sub{display:block;color:var(--muted);margin-top:3px}
/* inside a narrow duo column the 180px key column starves the value column */
.duo .spec__row,.duo--wide .spec__row,.geo .spec__row{grid-template-columns:minmax(0,118px) minmax(0,1fr);gap:8px 18px}

/* --- 11. Cards / modules ------------------------------------------------- */
.grid{display:grid;gap:1px;background:var(--line);border:1px solid var(--line)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--4{grid-template-columns:repeat(4,minmax(0,1fr))}
.cell{background:var(--ink);padding:clamp(20px,2.4vw,30px);min-width:0;display:flex;flex-direction:column}
.section--band .cell{background:var(--ink-2)}
.cell__idx{margin-bottom:14px}
.cell h3{margin-bottom:10px}
.cell p{font-size:var(--t-small);line-height:1.66;flex:1 1 auto}
.cell__list{margin-top:16px;border-top:1px solid var(--line);padding-top:14px}
.cell__list li{display:flex;gap:10px;font-family:var(--mono);font-size:.6875rem;line-height:1.6;color:var(--faint);padding-block:4px;letter-spacing:.02em}
.cell__list li b{color:var(--muted);font-weight:400;flex:none;width:60px}
.cell__link{margin-top:0;padding-top:18px;display:inline-block;align-self:flex-start;font-family:var(--mono);font-size:var(--t-label);letter-spacing:.14em;text-transform:uppercase}

/* tolerance list (operating conditions) */
.tol{border-top:1px solid var(--line)}
.tol li{
  display:grid;grid-template-columns:minmax(0,220px) minmax(0,1fr);
  gap:10px 28px;padding:20px 0;border-bottom:1px solid var(--line);align-items:start;
}
.tol__k{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.15em;text-transform:uppercase;color:var(--gold);padding-top:4px}
.tol__v{font-size:var(--t-small);line-height:1.68;color:var(--muted)}
.tol__v b{color:var(--text);font-weight:500}

/* negative-space / limits list */
.limits{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1px;background:var(--line);border:1px solid var(--line)}
.limits li{background:var(--ink);padding:22px 24px;min-width:0}
.section--band .limits li{background:var(--ink-2)}
.limits .lab{margin-bottom:9px}
.limits p{font-size:var(--t-small);line-height:1.62}

/* phase / step sequence */
.phases{counter-reset:ph;border-top:1px solid var(--line)}
.phases li{padding:26px 0;border-bottom:1px solid var(--line);display:grid;grid-template-columns:minmax(0,240px) minmax(0,1fr);gap:14px 28px}
.phases__h{}
.phases__n{color:var(--gold);margin-bottom:8px}
.phases__t{font-size:var(--t-h3);font-weight:500;letter-spacing:-.01em}
.phases__b p{font-size:var(--t-small);line-height:1.68}
.phases__b p+p{margin-top:12px}
.phases__meta{margin-top:14px;display:flex;flex-wrap:wrap;gap:6px 22px}

/* numbered procedure */
.proc{counter-reset:st;margin-top:18px}
.proc li{
  counter-increment:st;position:relative;padding:11px 0 11px 44px;
  border-bottom:1px solid var(--line);font-size:var(--t-small);line-height:1.62;color:var(--muted);
}
.proc li:last-child{border-bottom:0}
.proc li::before{
  content:counter(st,decimal-leading-zero);position:absolute;left:0;top:13px;
  font-family:var(--mono);font-size:.6875rem;letter-spacing:.12em;color:var(--gold);
}

/* bulleted deliverables */
.bul li{position:relative;padding:7px 0 7px 22px;font-size:var(--t-small);line-height:1.62;color:var(--muted)}
.bul li::before{content:"";position:absolute;left:0;top:16px;width:7px;height:1px;background:var(--gold-dim)}

/* --- 12. Long-form legal prose ------------------------------------------- */
.legal{max-width:74ch}
.legal h2{font-size:clamp(1.2rem,2vw,1.42rem);margin-top:52px;margin-bottom:14px;padding-top:22px;border-top:1px solid var(--line)}
.legal h2:first-of-type{margin-top:0;border-top:0;padding-top:0}
.legal h3{margin-top:28px;margin-bottom:8px;font-size:1.02rem}
.legal p{margin-bottom:14px;font-size:var(--t-small);line-height:1.74}
.legal ul{margin:0 0 16px}
.legal ul li{position:relative;padding:6px 0 6px 22px;font-size:var(--t-small);line-height:1.66;color:var(--muted)}
.legal ul li::before{content:"";position:absolute;left:0;top:15px;width:7px;height:1px;background:var(--gold-dim)}
.legal__meta{border:1px solid var(--line);border-radius:var(--r);padding:18px 20px;margin-bottom:44px;display:grid;gap:10px}
.legal__meta div{display:grid;grid-template-columns:minmax(0,124px) minmax(0,1fr);gap:4px 18px;align-items:baseline}
@media (max-width:520px){.legal__meta div{grid-template-columns:1fr;gap:2px}}
.legal__meta span:last-child{font-size:var(--t-small);color:var(--text)}
.toc{border:1px solid var(--line);border-radius:var(--r);padding:18px 20px;margin-bottom:44px}
.toc ol{margin-top:12px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 24px;counter-reset:tc}
.toc li{counter-increment:tc}
.toc a{font-size:var(--t-small);color:var(--muted);text-decoration:none;display:flex;gap:10px}
.toc a::before{content:counter(tc,decimal-leading-zero);font-family:var(--mono);font-size:.6875rem;color:var(--gold);flex:none}
.toc a:hover{color:var(--text);text-decoration:none}

/* --- 13. CTA block ------------------------------------------------------- */
.cta{border:1px solid var(--line-2);border-radius:var(--r);padding:clamp(28px,4vw,54px);position:relative;background:var(--surface)}
.cta::before,.cta::after{content:"";position:absolute;width:9px;height:9px;border-color:var(--gold-dim);border-style:solid}
.cta::before{top:-1px;left:-1px;border-width:1px 0 0 1px}
.cta::after{bottom:-1px;right:-1px;border-width:0 1px 1px 0}
.cta h2{font-size:var(--t-h2);max-width:22ch;margin-bottom:16px}
.cta p{max-width:56ch;font-size:var(--t-small)}
.cta .btnrow{margin-top:28px}

/* --- 14. Footer ---------------------------------------------------------- */
.ftr{border-top:1px solid var(--line);background:var(--ink-2);padding-block:clamp(44px,6vw,72px) 34px}
.ftr__top{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.45fr);gap:clamp(28px,5vw,64px);align-items:start}
.ftr__mark{display:flex;align-items:center;gap:11px;color:var(--gold);margin-bottom:16px}
.ftr__mark svg{width:26px;height:26px;flex:none}
.ftr__mark span{font-weight:700;font-size:.95rem;letter-spacing:.24em;color:var(--text);text-transform:uppercase}
.ftr__line{font-size:var(--t-small);color:var(--muted);max-width:38ch;line-height:1.6}
.identity{border-top:1px solid var(--line)}
.identity div{
  display:grid;grid-template-columns:minmax(0,126px) minmax(0,1fr);
  gap:6px 24px;padding:11px 0;border-bottom:1px solid var(--line);
}
.identity dt{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.15em;text-transform:uppercase;color:var(--faint);padding-top:2px}
.identity dd{margin:0;font-size:var(--t-small);color:var(--text);overflow-wrap:anywhere}
.identity dd a{color:var(--text);border-bottom:1px solid var(--gold-dim);text-decoration:none}
.identity dd a:hover{color:var(--gold);text-decoration:none}
.ftr__bottom{
  margin-top:34px;padding-top:22px;border-top:1px solid var(--line);
  display:flex;flex-wrap:wrap;gap:14px 28px;justify-content:space-between;align-items:baseline;
}
.ftr__nav{display:flex;flex-wrap:wrap;gap:10px 22px}
.ftr__nav a{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.14em;text-transform:uppercase;color:var(--muted);text-decoration:none}
.ftr__nav a:hover{color:var(--gold);text-decoration:none}
.ftr__copy{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.1em;color:var(--faint)}

/* --- 15. Responsive ------------------------------------------------------ */
@media (max-width:1020px){
  .grid--4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .channels{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media (max-width:900px){
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .ftr__top{grid-template-columns:1fr}
  .phases li{grid-template-columns:1fr}
  .tol li{grid-template-columns:1fr;gap:6px}
}
@media (max-width:760px){
  .hdr__in{flex-wrap:wrap;padding-block:12px;gap:12px}
  .hdr .nav{order:3;width:100%;border-top:1px solid var(--line);padding-top:11px;justify-content:space-between;gap:10px}
  .hero h1{max-width:none}
  .specstrip{grid-template-columns:1fr}
  .specstrip>div{border-right:0;border-bottom:1px solid var(--line);padding:14px 0}
  .specstrip>div:last-child{border-bottom:0}
  .channels{grid-template-columns:repeat(2,minmax(0,1fr))}
  .toc ol{grid-template-columns:1fr}
}
@media (max-width:620px){
  .grid--2,.grid--3,.grid--4{grid-template-columns:1fr}
  .limits{grid-template-columns:1fr}
  .channels{grid-template-columns:1fr}
  .spec__row{grid-template-columns:1fr;gap:4px}
  .identity div{grid-template-columns:1fr;gap:3px}
  .trace li{grid-template-columns:38px minmax(0,1fr);gap:4px 10px;row-gap:2px}
  .trace .sink{grid-column:2}
  .trace .st{grid-column:2;text-align:left}
  .shead{flex-wrap:wrap;gap:10px}
  .shead__rule{display:none}
  .cell__list li{flex-wrap:wrap;gap:2px 10px}
  .cell__list li b{width:auto}
}
@media (max-width:420px){
  .nav{gap:8px}
  .nav a{font-size:.625rem;letter-spacing:.1em}
  .brand__wm{letter-spacing:.18em;font-size:.875rem}
  .btn{padding:12px 16px;font-size:.625rem;letter-spacing:.12em}
  .btnrow{gap:10px}
  .btnrow .btn{width:100%;justify-content:center}
}

/* --- 16. Reduced motion -------------------------------------------------- */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
  .rail__pulse{display:none}
  .led{background:var(--gold-dim)!important;box-shadow:none!important}
  .ch:nth-child(1) .led{background:var(--gold)!important}
}

/* --- 17. Print ----------------------------------------------------------- */
@media print{
  .hdr,.rail__pulse{display:none}
  body{background:#fff;color:#000}
  a{color:#000}
}

/* --- 18. Page header (interior pages) ------------------------------------ */
.phead{padding-block:clamp(48px,6.5vw,84px) clamp(30px,4vw,44px);border-bottom:1px solid var(--line);position:relative;overflow:hidden}
.phead::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(255,255,255,.03) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.03) 1px,transparent 1px);
  background-size:46px 46px;
  -webkit-mask-image:radial-gradient(135% 110% at 12% 0%,#000 0%,rgba(0,0,0,.5) 40%,transparent 78%);
  mask-image:radial-gradient(135% 110% at 12% 0%,#000 0%,rgba(0,0,0,.5) 40%,transparent 78%);
}
.phead__in{position:relative}
.phead h1{font-size:clamp(2rem,4.6vw,3.05rem);font-weight:500;letter-spacing:-.028em;line-height:1.08;max-width:20ch;margin-top:20px;overflow-wrap:break-word}
.phead__sub{margin-top:20px;max-width:62ch;font-size:clamp(1rem,1.35vw,1.1rem);line-height:1.64}

/* --- 19. Two-column duo + chapters --------------------------------------- */
.duo{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:clamp(26px,4vw,56px)}
.duo--wide{grid-template-columns:minmax(0,1.25fr) minmax(0,1fr)}
@media (max-width:800px){.duo,.duo--wide{grid-template-columns:1fr;gap:30px}}
.chapter{padding-block:clamp(52px,7vw,86px);border-top:1px solid var(--line)}
.phead + .chapter{border-top:0}
.block__h{margin-bottom:14px}
.sub-rule{border-top:1px solid var(--line);margin-top:32px;padding-top:26px}

/* index list of channels */
.idxlist{border-top:1px solid var(--line);margin-top:34px}
.idxlist a{
  display:grid;grid-template-columns:minmax(0,74px) minmax(0,1fr) auto;gap:12px 22px;align-items:baseline;
  padding:15px 0;border-bottom:1px solid var(--line);text-decoration:none;color:var(--text);
  transition:padding-left var(--dur) var(--ease);
}
.idxlist a:hover{text-decoration:none;padding-left:8px}
.idxlist a:hover .idxlist__t{color:var(--gold)}
.idxlist__n{font-family:var(--mono);font-size:var(--t-label);letter-spacing:.15em;color:var(--gold)}
.idxlist__t{font-size:var(--t-small);font-weight:500;transition:color var(--dur) var(--ease)}
.idxlist__d{font-family:var(--mono);font-size:.6875rem;color:var(--faint);letter-spacing:.02em;text-align:right}
@media (max-width:620px){
  .idxlist a{grid-template-columns:minmax(0,60px) minmax(0,1fr);row-gap:3px}
  .idxlist__d{grid-column:2;text-align:left}
}

/* callout */
.note{border-left:1px solid var(--gold-dim);padding:4px 0 4px 20px;margin-top:26px;max-width:68ch}
.note p{font-size:var(--t-small);line-height:1.66}

/* contact rows */
.contact-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1px;background:var(--line);border:1px solid var(--line);margin-top:34px}
.contact-grid>div{background:var(--ink);padding:clamp(22px,3vw,32px);min-width:0}
.section--band .contact-grid>div{background:var(--ink-2)}
.contact-grid .v{font-size:1.02rem;margin:10px 0 6px;color:var(--text);overflow-wrap:anywhere;font-weight:500}
.contact-grid p{font-size:var(--t-small);line-height:1.62}
@media (max-width:620px){.contact-grid{grid-template-columns:1fr}}

/* mark geometry figure */
.geo{display:grid;grid-template-columns:minmax(0,254px) minmax(0,1fr);gap:clamp(22px,4vw,48px);align-items:start}
.geo__art{color:var(--gold);width:100%;max-width:254px;margin-inline:auto}
.swatch{margin-top:20px;border-top:1px solid var(--line)}
.swatch div{display:flex;align-items:center;gap:11px;padding:9px 0;border-bottom:1px solid var(--line)}
.swatch i{display:block;width:15px;height:15px;border-radius:1px;flex:none;box-shadow:inset 0 0 0 1px var(--line-2)}
.swatch b{font-family:var(--mono);font-size:.6875rem;letter-spacing:.1em;color:var(--text);font-weight:500}
.swatch span{font-family:var(--mono);font-size:.6875rem;letter-spacing:.12em;text-transform:uppercase;color:var(--faint);margin-left:auto}
@media (max-width:620px){.geo{grid-template-columns:1fr}}

/* --- 20. Timeline rail (FIG. 03) ----------------------------------------- */
.tl{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0}
.tl li{position:relative;padding:26px 18px 4px 0;border-top:1px solid var(--line)}
.tl li::before{
  content:"";position:absolute;top:-4px;left:0;width:7px;height:7px;border-radius:1px;
  background:var(--gold);
}
.tl li:last-child::before{background:var(--surface);box-shadow:inset 0 0 0 1px var(--gold-dim)}
.tl__n{display:block;font-family:var(--mono);font-size:.6875rem;letter-spacing:.15em;text-transform:uppercase;color:var(--gold);margin-bottom:7px}
.tl__t{display:block;font-size:1rem;font-weight:500;color:var(--text);margin-bottom:7px;line-height:1.3}
.tl__d{display:block;font-size:.8125rem;line-height:1.55;color:var(--muted)}
@media (max-width:760px){
  .tl{grid-template-columns:1fr}
  .tl li{padding:16px 0 16px 24px;border-top:0;border-left:1px solid var(--line)}
  .tl li::before{top:20px;left:-4px}
}

/* --- 21. Inline code + misc ---------------------------------------------- */
code{font-family:var(--mono);font-size:.92em;color:var(--text);background:rgba(255,255,255,.05);padding:1px 5px;border-radius:var(--r);overflow-wrap:anywhere}
.legal code{font-size:.86em}
abbr{text-decoration:none;border-bottom:1px dotted var(--faint)}

/* --- 22. Legal document layout (sticky contents rail) -------------------- */
.legaldoc{display:grid;grid-template-columns:222px minmax(0,1fr);gap:clamp(30px,5vw,64px);align-items:start}
.legaldoc__nav{position:sticky;top:86px}
.legaldoc .legal{max-width:72ch}
.legaldoc .toc{margin-bottom:0;padding:16px 18px}
.legaldoc .toc ol{grid-template-columns:1fr;gap:3px}
.legaldoc .toc a{padding-block:3px;font-size:.8125rem;line-height:1.4}
@media (max-width:900px){
  .legaldoc{grid-template-columns:1fr}
  .legaldoc__nav{position:static;margin-bottom:40px}
  .legaldoc .toc ol{grid-template-columns:repeat(2,minmax(0,1fr));gap:5px 22px}
}
@media (max-width:560px){
  .legaldoc .toc ol{grid-template-columns:1fr}
}

/* --- 23. Symptom list (§01 home) ----------------------------------------- */
.symp{border-top:1px solid var(--line)}
.symp li{
  display:flex;gap:12px;align-items:baseline;
  padding:12px 0;border-bottom:1px solid var(--line);
  font-size:.875rem;line-height:1.55;color:var(--muted);
}
.symp li i{
  font-family:var(--mono);font-style:normal;font-size:.625rem;letter-spacing:.12em;
  color:var(--gold);flex:none;padding-top:2px;
}