/* ─────────────────────────────────────────────────────────────
   Set Energy Pty Ltd — setenergy.com.au
   v2 · minimal / technical / dark-first
   Instrument panel, not a brochure: near-black canvas, hairline
   rules, one plasma-cyan accent, photon amber reserved for data.
   Light theme is a full inversion, not an afterthought.
   ───────────────────────────────────────────────────────────── */

:root{
  color-scheme:dark light;

  --canvas:#06080B;
  --panel:#0A0E13;
  --panel-2:#0E141B;
  --raised:#121A23;
  --line:rgba(255,255,255,.09);
  --line-2:rgba(255,255,255,.05);
  --line-strong:rgba(255,255,255,.17);

  --ink:#EEF4F9;
  --body:#B4C4D2;
  --mute:#7C8FA1;
  --faint:#5A6B7B;

  --acc:#19B899;          /* brand teal, lifted for dark backgrounds */
  --acc-dim:rgba(25,184,153,.14);
  --acc-txt:#19B899;
  --acc2:#FFC14D;         /* photon amber — data values, spec */
  --acc2-txt:#FFC14D;
  --grid:rgba(255,255,255,.05);   /* hero backdrop only — fainter than a hairline */

  --measure:68ch;
  --shell:1240px;

  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
  --disp:"Space Grotesk",system-ui,sans-serif;
  --read:"Inter",system-ui,-apple-system,"Segoe UI",sans-serif;

  --ease:cubic-bezier(.22,.61,.36,1);
}

@media (prefers-color-scheme: light){
  :root{
    --canvas:#F6F8FA;
    --panel:#FFFFFF;
    --panel-2:#FFFFFF;
    --raised:#F0F4F7;
    --line:rgba(9,18,28,.13);
    --line-2:rgba(9,18,28,.07);
    --line-strong:rgba(9,18,28,.26);

    --ink:#080D14;
    --body:#33475A;
    --mute:#5E7387;
    --faint:#8296A8;

    --acc:#0C7965;
    --acc-dim:rgba(12,121,101,.12);
    --acc-txt:#0A6E5C;
    --acc2:#B06E00;
    --acc2-txt:#8A5600;
    --grid:rgba(9,18,28,.04);
  }
}

/* explicit toggle wins over the system preference, both directions */
:root[data-theme="light"]{
  color-scheme:light;
  --canvas:#F6F8FA; --panel:#FFFFFF; --panel-2:#FFFFFF; --raised:#F0F4F7;
  --line:rgba(9,18,28,.13); --line-2:rgba(9,18,28,.07); --line-strong:rgba(9,18,28,.26);
  --ink:#080D14; --body:#33475A; --mute:#5E7387; --faint:#8296A8;
  --acc:#0C7965; --acc-dim:rgba(12,121,101,.12); --acc-txt:#0A6E5C;
  --acc2:#B06E00; --acc2-txt:#8A5600;
  --grid:rgba(9,18,28,.04);
}
:root[data-theme="dark"]{
  color-scheme:dark;
  --canvas:#06080B; --panel:#0A0E13; --panel-2:#0E141B; --raised:#121A23;
  --line:rgba(255,255,255,.09); --line-2:rgba(255,255,255,.05); --line-strong:rgba(255,255,255,.17);
  --ink:#EEF4F9; --body:#B4C4D2; --mute:#7C8FA1; --faint:#5A6B7B;
  --acc:#19B899; --acc-dim:rgba(25,184,153,.14); --acc-txt:#19B899;
  --acc2:#FFC14D; --acc2-txt:#FFC14D;
  --grid:rgba(255,255,255,.05);
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;background:var(--canvas);color:var(--body);
  font-family:var(--read);font-size:17px;line-height:1.68;
  font-feature-settings:"cv05" 1,"ss01" 1;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
}
img{max-width:100%;height:auto}
::selection{background:var(--acc);color:var(--canvas)}

/* ── shell ─────────────────────────────────────────────── */
.shell{width:100%;max-width:var(--shell);margin:0 auto;padding:0 clamp(20px,4.5vw,52px)}
.narrow{max-width:var(--measure)}

.skip{position:absolute;left:-9999px;top:0;background:var(--acc);color:#04070A;padding:11px 18px;z-index:80;font-family:var(--mono);font-size:12px;font-weight:500}
.skip:focus{left:10px;top:10px}

.progress{position:fixed;top:0;left:0;height:2px;width:0;background:linear-gradient(90deg,var(--acc),var(--acc2));z-index:70;box-shadow:0 0 12px var(--acc)}

/* ── masthead ──────────────────────────────────────────── */
.masthead{
  position:sticky;top:0;z-index:50;
  background:color-mix(in srgb,var(--canvas) 86%,transparent);
  backdrop-filter:blur(14px) saturate(140%);
  border-bottom:1px solid var(--line);
}
.masthead .bar{display:flex;align-items:center;gap:clamp(14px,1.9vw,26px);padding:15px 0}

/* Real brand artwork. Two variants: the supplied logo uses a deep green that
   disappears on the dark canvas, so logo-dark.png carries a light knockout of
   that half. Only one is ever in the layout — and in the a11y tree. */
.wordmark{display:inline-flex;align-items:center;margin-right:auto;background:none;line-height:0;flex:none}
.wordmark img{display:block;height:27px;width:auto}
.wordmark:hover{background:none}
.wordmark .logo-light{display:none}
.wordmark .logo-dark{display:block}
:root[data-theme="light"] .wordmark .logo-light{display:block}
:root[data-theme="light"] .wordmark .logo-dark{display:none}
@media (prefers-color-scheme: light){
  :root:not([data-theme]) .wordmark .logo-light{display:block}
  :root:not([data-theme]) .wordmark .logo-dark{display:none}
}

/* footer mark */
.footmark{margin:0 0 26px}
.footmark img{display:block;height:30px;width:auto}
.footmark .logo-light{display:none}
.footmark .logo-dark{display:block}
:root[data-theme="light"] .footmark .logo-light{display:block}
:root[data-theme="light"] .footmark .logo-dark{display:none}
@media (prefers-color-scheme: light){
  :root:not([data-theme]) .footmark .logo-light{display:block}
  :root:not([data-theme]) .footmark .logo-dark{display:none}
}

.nav{display:flex;gap:clamp(11px,1.7vw,25px);align-items:center;order:3}
.nav a{font-family:var(--mono);font-size:11px;letter-spacing:.13em;text-transform:uppercase;color:var(--mute);text-decoration:none;background:none;padding:6px 0;border-bottom:1px solid transparent;transition:color .16s var(--ease),border-color .16s var(--ease)}
.nav a:hover,.nav a:focus-visible{color:var(--ink);border-bottom-color:var(--acc)}
.nav a[aria-current="page"]{color:var(--ink);border-bottom-color:var(--acc)}

.toggle{
  flex:none;order:4;width:32px;height:32px;display:grid;place-items:center;cursor:pointer;
  background:none;border:1px solid var(--line);color:var(--mute);border-radius:2px;
  transition:color .16s var(--ease),border-color .16s var(--ease)
}
.toggle:hover{color:var(--acc);border-color:var(--acc)}
.toggle svg{width:15px;height:15px;fill:none;stroke:currentColor;stroke-width:1.6}
.toggle .sun{display:none}
:root[data-theme="light"] .toggle .sun{display:block}
:root[data-theme="light"] .toggle .moon{display:none}
@media (prefers-color-scheme: light){
  :root:not([data-theme]) .toggle .sun{display:block}
  :root:not([data-theme]) .toggle .moon{display:none}
}

/* ── spec rail: the running entity strip ───────────────── */
.specrail{border-bottom:1px solid var(--line);background:var(--panel)}
.specrail .row{display:flex;flex-wrap:wrap;gap:5px clamp(16px,2.8vw,36px);padding:9px 0;font-family:var(--mono);font-size:10px;letter-spacing:.11em;text-transform:uppercase}
.specrail em{font-style:normal;color:var(--faint)}
.specrail b{color:var(--acc2-txt);font-weight:500}

/* ── type ──────────────────────────────────────────────── */
h1,h2,h3,h4{font-family:var(--disp);color:var(--ink);letter-spacing:-.03em;line-height:1.1;margin:0;font-weight:500;text-wrap:balance}
h1{font-size:clamp(32px,5vw,58px);font-weight:700;letter-spacing:-.04em}
h2{font-size:clamp(24px,3.1vw,35px);font-weight:600;margin:2.5em 0 .6em;letter-spacing:-.035em}
h3{font-size:clamp(18px,2vw,21px);font-weight:600;margin:2.1em 0 .5em;letter-spacing:-.02em}
h4{font-size:16px;font-weight:600;margin:1.7em 0 .4em}
p{margin:0 0 1.2em}
strong{color:var(--ink);font-weight:600}

a{color:var(--acc-txt);text-decoration:none;background-image:linear-gradient(currentColor,currentColor);background-size:0% 1px;background-repeat:no-repeat;background-position:0 100%;transition:background-size .22s var(--ease),color .16s var(--ease)}
.prose a,.faq a,.foot a,.crumbs a,p a{background-size:100% 1px;background-position:0 calc(100% - 1px)}
.prose a:hover,.faq a:hover,p a:hover{color:var(--ink)}
:focus-visible{outline:2px solid var(--acc);outline-offset:3px;border-radius:1px}

.eyebrow{font-family:var(--mono);font-size:10.5px;letter-spacing:.28em;text-transform:uppercase;color:var(--acc2-txt);margin:0 0 16px}
.lede{font-size:clamp(18px,2.1vw,21px);line-height:1.58;color:var(--body);text-wrap:pretty}
h1+.lede,h2+.lede{margin-top:clamp(18px,2.4vh,26px)}
.dek{font-family:var(--mono);font-size:11.5px;letter-spacing:.07em;color:var(--mute);margin:0}

/* ── hero ──────────────────────────────────────────────── */
.hero{position:relative;overflow:hidden;padding:clamp(52px,9vh,104px) 0 clamp(38px,6vh,64px);border-bottom:1px solid var(--line)}
.hero::before{
  content:"";position:absolute;inset:0;z-index:0;pointer-events:none;
  background:
    radial-gradient(720px 340px at 12% -8%, var(--acc-dim), transparent 68%),
    linear-gradient(to right, var(--grid) 1px, transparent 1px) 0 0/clamp(88px,9vw,120px) clamp(88px,9vw,120px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px) 0 0/clamp(88px,9vw,120px) clamp(88px,9vw,120px);
  -webkit-mask-image:linear-gradient(to bottom,#000,transparent 88%);
          mask-image:linear-gradient(to bottom,#000,transparent 88%);
}
.hero>*{position:relative;z-index:1}
.hero .grid{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,.95fr);gap:clamp(30px,5vw,72px);align-items:start}
@media(max-width:900px){.hero .grid{grid-template-columns:1fr}}

/* ── title block: the signature data panel ─────────────── */
.titleblock{border:1px solid var(--line);background:var(--panel);font-family:var(--mono);font-size:11px;letter-spacing:.05em;line-height:1.5;border-radius:3px;overflow:hidden}
.titleblock .tb-head{background:var(--raised);color:var(--acc2-txt);padding:9px 14px;display:flex;justify-content:space-between;gap:14px;text-transform:uppercase;font-size:10px;letter-spacing:.16em;border-bottom:1px solid var(--line)}
.titleblock dl{display:grid;grid-template-columns:auto 1fr;margin:0}
.titleblock dt{padding:8px 14px;color:var(--faint);border-top:1px solid var(--line-2);white-space:nowrap;text-transform:uppercase;font-size:10px;letter-spacing:.11em}
.titleblock dt:first-of-type,.titleblock dd:first-of-type{border-top:0}
.titleblock dd{padding:8px 14px;margin:0;color:var(--ink);border-top:1px solid var(--line-2);border-left:1px solid var(--line-2)}
.titleblock dd a{color:var(--acc-txt)}

/* ── sections ──────────────────────────────────────────── */
.section{padding:clamp(50px,8vh,92px) 0;border-bottom:1px solid var(--line)}
/* section that sits directly under a page's title block — no rule, less air */
.section.tight{border-top:0;padding-top:clamp(24px,3.5vh,44px)}
.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:22px;flex-wrap:wrap;margin-bottom:clamp(24px,3.4vh,38px)}
.section-head h2{margin:0}

/* ── answer box: the AI-liftable summary ───────────────── */
.answerbox{
  position:relative;border:1px solid var(--line);border-left:2px solid var(--acc);
  background:var(--panel);padding:20px 24px;margin:0 0 34px;border-radius:3px;
}
.answerbox .lbl{display:block;font-family:var(--mono);font-size:9.5px;letter-spacing:.22em;text-transform:uppercase;color:var(--acc-txt);margin-bottom:9px}
.answerbox p{margin:0;font-size:17px;line-height:1.62;color:var(--ink)}

/* ── cards ─────────────────────────────────────────────── */
/* hairlines live on the cards, not on a background showing through gaps —
   an incomplete last row would otherwise render as a stray lighter block */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(262px,1fr));border-top:1px solid var(--line);border-left:1px solid var(--line)}
.card{background:var(--panel);padding:26px 24px 28px;display:flex;flex-direction:column;gap:10px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);transition:background .18s var(--ease)}
.card:hover{background:var(--panel-2)}
.card .tag{font-family:var(--mono);font-size:9.5px;letter-spacing:.2em;text-transform:uppercase;color:var(--faint)}
.card h3{margin:0;font-size:19px}
.card h3 a{color:var(--ink);background:none}
.card:hover h3 a{color:var(--acc-txt)}
.card p{margin:0;font-size:15.5px;line-height:1.6}

/* ── stack list (guides index) ─────────────────────────── */
.stack{border-top:1px solid var(--line);list-style:none;padding:0;margin:0}
.stack li{list-style:none}
.stack .item{display:grid;grid-template-columns:118px minmax(0,1fr);gap:clamp(16px,3vw,36px);padding:24px 0;border-bottom:1px solid var(--line);transition:border-color .18s var(--ease)}
.stack .item:hover{border-bottom-color:var(--line-strong)}
.stack .item .meta{font-family:var(--mono);font-size:10px;letter-spacing:.16em;text-transform:uppercase;color:var(--faint);padding-top:6px}
.stack .item h3{margin:0 0 7px;font-size:20px}
.stack .item h3 a{color:var(--ink);background:none}
.stack .item:hover h3 a{color:var(--acc-txt)}
.stack .item p{margin:0;font-size:16px}
@media(max-width:660px){.stack .item{grid-template-columns:1fr;gap:7px}}

/* ── article ───────────────────────────────────────────── */
.article{padding:clamp(36px,5vh,60px) 0 0}
.article-grid{display:grid;grid-template-columns:minmax(0,1fr) 226px;gap:clamp(30px,5vw,66px);align-items:start}
.article-grid>*{min-width:0}
/* minmax(0,…) not 1fr — a plain 1fr track floors at min-content and overflows narrow viewports */
@media(max-width:1020px){.article-grid{grid-template-columns:minmax(0,1fr)}.toc{position:static!important;display:none}}
.prose{max-width:var(--measure)}
.prose>:first-child{margin-top:0}
.prose h2,.prose h3{scroll-margin-top:120px}
.prose ul,.prose ol{margin:0 0 1.35em;padding-left:1.3em}
.prose li{margin:0 0 .55em}
.prose li::marker{color:var(--faint)}
.prose blockquote{margin:1.7em 0;padding:2px 0 2px 22px;border-left:2px solid var(--acc2);color:var(--ink);font-size:18px}

.toc{position:sticky;top:112px;font-family:var(--mono);font-size:11px;line-height:1.5}
.toc p{font-size:9.5px;letter-spacing:.22em;text-transform:uppercase;color:var(--faint);margin:0 0 12px;padding-bottom:10px;border-bottom:1px solid var(--line)}
.toc ol{list-style:none;margin:0;padding:0}
.toc li{margin:0 0 9px}
.toc a{color:var(--mute);background:none;display:block;transition:color .16s var(--ease)}
.toc a:hover{color:var(--acc-txt);background:none}

/* ── tables ────────────────────────────────────────────── */
.tablewrap{overflow-x:auto;margin:1.8em 0;border:1px solid var(--line);border-radius:3px}
table{border-collapse:collapse;width:100%;background:var(--panel);font-family:var(--mono);font-size:12.5px}
caption{caption-side:top;text-align:left;padding:11px 15px;background:var(--raised);color:var(--acc2-txt);font-family:var(--mono);font-size:10px;letter-spacing:.16em;text-transform:uppercase;border-bottom:1px solid var(--line)}
th,td{padding:11px 15px;text-align:left;border-bottom:1px solid var(--line-2);vertical-align:top;line-height:1.55}
th{color:var(--ink);font-weight:500;background:var(--panel-2);white-space:nowrap}
tbody tr:last-child td{border-bottom:0}
tbody tr:hover td{background:var(--panel-2)}
td.num,th.num{text-align:right;font-variant-numeric:tabular-nums}

/* ── callouts ──────────────────────────────────────────── */
.note{border:1px solid var(--line);border-left:2px solid var(--acc);background:var(--panel);padding:18px 22px;margin:1.8em 0;font-size:16px;border-radius:3px}
.note.warn{border-left-color:var(--acc2)}
.note .lbl{display:block;font-family:var(--mono);font-size:9.5px;letter-spacing:.2em;text-transform:uppercase;color:var(--mute);margin-bottom:8px}
.note p:last-child{margin-bottom:0}

/* ── worked example ────────────────────────────────────── */
.calc{border:1px solid var(--line);background:var(--panel);margin:1.9em 0;font-family:var(--mono);font-size:13px;border-radius:3px;overflow:hidden}
.calc .ch{background:var(--raised);color:var(--acc2-txt);padding:9px 15px;font-size:10px;letter-spacing:.16em;text-transform:uppercase;border-bottom:1px solid var(--line)}
.calc .cb{padding:15px 17px}
.calc .line{display:flex;justify-content:space-between;gap:18px;padding:6px 0;border-bottom:1px dotted var(--line)}
.calc .line:last-child{border-bottom:0}
.calc .line.total{border-top:1px solid var(--line-strong);border-bottom:0;margin-top:7px;padding-top:10px;color:var(--acc2-txt);font-weight:500}
.calc .line span:last-child{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap;color:var(--ink)}
.calc .line.total span:last-child{color:var(--acc2-txt)}
/* a line that is one long value — a URL or a snippet — not a label/value pair */
.calc .line.code{display:block}
.calc .line.code span{white-space:pre-wrap;overflow-wrap:anywhere;text-align:left;color:var(--ink)}

/* ── figures: photography ──────────────────────────────── */
/* Photographs are illustrative stock, never presented as our own jobs — the
   caption carries the teaching point, not a claim about the site pictured. */
.fig{margin:2em 0;border:1px solid var(--line);border-radius:3px;overflow:hidden;background:var(--panel)}
.fig img{display:block;width:100%;height:auto;filter:saturate(.88) brightness(.94) contrast(1.03)}
:root[data-theme="light"] .fig img{filter:saturate(.96)}
@media (prefers-color-scheme: light){
  :root:not([data-theme]) .fig img{filter:saturate(.96)}
}
.fig figcaption{
  font-family:var(--mono);font-size:11px;line-height:1.6;letter-spacing:.03em;color:var(--mute);
  padding:11px 15px;border-top:1px solid var(--line);background:var(--panel)
}
.fig figcaption b{color:var(--acc2-txt);font-weight:500}

/* page lead image — sits between the title block and the body copy */
.leadfig{margin:0 0 clamp(24px,3.4vh,38px)}

/* ── diagrams: inline SVG, themed by the same tokens ───── */
.dia{margin:2.2em 0;border:1px solid var(--line);border-radius:3px;background:var(--panel);overflow:hidden}
.dia .dh{
  background:var(--raised);color:var(--acc2-txt);padding:9px 15px;font-family:var(--mono);
  font-size:10px;letter-spacing:.16em;text-transform:uppercase;border-bottom:1px solid var(--line);
  display:flex;justify-content:space-between;gap:14px
}
.dia .db{padding:16px 15px;overflow-x:auto}
.dia svg{display:block;width:100%;height:auto;overflow:visible}
/* Below this the labels inside a 640-unit diagram fall under about 6px. Panning
   sideways beats squinting, and it is what the tables on this site already do. */
@media(max-width:660px){.dia svg{min-width:540px}}
.dia svg text{font-family:var(--mono);fill:var(--mute)}
.dia svg .lbl-i{font-size:11px;letter-spacing:.04em}
.dia svg .lbl-s{font-size:9.5px;letter-spacing:.1em;text-transform:uppercase;fill:var(--faint)}
/* same weight as .lbl-s but never uppercased — units are case-significant, and
   a page about the difference between kW and kWh cannot render either as KWH */
.dia svg .lbl-n{font-size:9.5px;letter-spacing:.06em;text-transform:none;fill:var(--faint)}
/* label sitting on top of a filled area — needs the contrast of body text */
.dia svg .lbl-f{font-size:10px;letter-spacing:.04em;text-transform:none;fill:var(--ink)}
.dia svg .lbl-v{font-size:11.5px;fill:var(--ink)}
.dia svg .lbl-a{fill:var(--acc)}
.dia svg .lbl-b{fill:var(--acc2)}
.dia svg .box{fill:var(--raised);stroke:var(--line-strong);stroke-width:1}
.dia svg .rule{stroke:var(--line);stroke-width:1}
.dia svg .rule-2{stroke:var(--line-2);stroke-width:1}
.dia svg .flow{stroke:var(--acc);stroke-width:1.6;fill:none}
.dia svg .flow-2{stroke:var(--acc2);stroke-width:1.6;fill:none}
.dia svg .dash{stroke-dasharray:4 4}
.dia figcaption{
  font-family:var(--mono);font-size:11px;line-height:1.6;color:var(--mute);
  padding:0 15px 14px;background:var(--panel)
}

/* ── collapsible sections ──────────────────────────────── */
/* Long reference pages fold their <h2> sections. The heading stays a real h2
   inside the summary, so the document outline and the anchors are unchanged. */
.prose.folded{max-width:none}
.prose.folded>*{max-width:var(--measure)}
.sec{border-bottom:1px solid var(--line);max-width:var(--measure)}
.sec:first-of-type{border-top:1px solid var(--line)}
.sec>summary{
  cursor:pointer;list-style:none;display:flex;align-items:baseline;gap:18px;
  padding:20px 0;transition:color .16s var(--ease)
}
.sec>summary::-webkit-details-marker{display:none}
.sec>summary h2{
  margin:0;flex:1;font-size:clamp(19px,2.2vw,25px);font-weight:600;letter-spacing:-.03em;
  transition:color .16s var(--ease)
}
.sec>summary:hover h2{color:var(--acc-txt)}
.sec>summary::after{
  content:"";flex:none;width:10px;height:10px;margin-top:8px;
  border-right:1.5px solid var(--acc);border-bottom:1.5px solid var(--acc);
  transform:rotate(45deg);transition:transform .2s var(--ease)
}
.sec[open]>summary::after{transform:rotate(225deg)}
.sec[open]>summary{padding-bottom:6px}
.sec-body{padding:0 0 26px}
.sec-body>:first-child{margin-top:0}
.sec-body h3{margin-top:1.6em}
/* the anchor lands on the <details>, so the offset belongs there */
.sec{scroll-margin-top:120px}

.expandbar{
  display:flex;align-items:baseline;justify-content:space-between;gap:16px;flex-wrap:wrap;
  margin:0 0 4px;padding-bottom:12px
}
.expandbar p{
  margin:0;font-family:var(--mono);font-size:10px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--faint)
}
.expandbar button{
  font-family:var(--mono);font-size:10px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--acc-txt);background:none;border:1px solid var(--line);border-radius:2px;
  padding:7px 13px;cursor:pointer;transition:color .16s var(--ease),border-color .16s var(--ease)
}
.expandbar button:hover{border-color:var(--acc);color:var(--ink)}

/* ── training components ───────────────────────────────── */
/* Two-column term list — glossary and the "say it like this" crib sheet. */
.defs{border:1px solid var(--line);border-radius:3px;background:var(--panel);margin:1.9em 0;overflow:hidden}
.defs dl{margin:0;display:grid;grid-template-columns:minmax(140px,190px) minmax(0,1fr)}
.defs dt{
  padding:12px 15px;border-top:1px solid var(--line-2);color:var(--acc2-txt);
  font-family:var(--mono);font-size:11.5px;letter-spacing:.03em;line-height:1.5
}
.defs dd{
  margin:0;padding:12px 15px;border-top:1px solid var(--line-2);border-left:1px solid var(--line-2);
  font-size:15px;line-height:1.6
}
.defs dt:first-of-type,.defs dd:first-of-type{border-top:0}
@media(max-width:620px){
  .defs dl{grid-template-columns:1fr}
  .defs dd{border-left:0;border-top:0;padding-top:0}
  .defs dt{padding-bottom:3px}
}

/* ── home media band ───────────────────────────────────── */
/* margin:0 defeats the UA's default 40px figure margin, which otherwise insets
   a band that is meant to run edge to edge and pushes its caption off-centre */
.mediaband{position:relative;margin:0;border-bottom:1px solid var(--line);overflow:hidden;background:var(--panel)}
.mediaband img{display:block;width:100%;height:clamp(220px,34vh,380px);object-fit:cover;
               filter:saturate(.8) brightness(.78) contrast(1.05)}
:root[data-theme="light"] .mediaband img{filter:saturate(.92) brightness(.97)}
@media (prefers-color-scheme: light){
  :root:not([data-theme]) .mediaband img{filter:saturate(.92) brightness(.97)}
}
/* The caption is a strip under the photograph rather than text laid over it —
   overlaid type survived neither the light theme nor a bright sky. */
.mediaband .cap{border-top:1px solid var(--line);background:var(--panel)}
.mediaband .cap div{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:6px 18px;justify-content:space-between;
  padding:13px 0
}
.mediaband .cap p{
  margin:0;font-family:var(--mono);font-size:11px;letter-spacing:.1em;color:var(--mute);
  text-transform:uppercase
}
.mediaband .cap a{
  font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--acc-txt);background:none;white-space:nowrap
}
.mediaband .cap a:hover{color:var(--ink)}

/* ── FAQ ───────────────────────────────────────────────── */
.faq{border-top:1px solid var(--line);margin:2.6em 0 0}
.faq details{border-bottom:1px solid var(--line)}
.faq summary{cursor:pointer;padding:17px 0;font-family:var(--disp);font-size:17.5px;font-weight:500;color:var(--ink);letter-spacing:-.02em;list-style:none;display:flex;justify-content:space-between;gap:18px;transition:color .16s var(--ease)}
.faq summary:hover{color:var(--acc-txt)}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"";flex:none;width:11px;height:11px;margin-top:7px;border-right:1.5px solid var(--acc);border-bottom:1.5px solid var(--acc);transform:rotate(45deg);transition:transform .2s var(--ease)}
.faq details[open] summary::after{transform:rotate(225deg)}
.faq .ans{padding:0 0 20px;font-size:16px;max-width:var(--measure)}
.faq .ans p:last-child{margin-bottom:0}

/* ── sources / related ─────────────────────────────────── */
.sources{margin:2.8em 0 0;padding-top:20px;border-top:1px solid var(--line);font-size:14.5px;color:var(--mute)}
.sources p.lbl{font-family:var(--mono);font-size:9.5px;letter-spacing:.2em;text-transform:uppercase;color:var(--faint);margin:0 0 11px}
.sources ol{padding-left:1.25em;margin:0}
.sources li{margin:0 0 .45em}

.related{margin:2.8em 0 0;padding-top:20px;border-top:1px solid var(--line)}
.related p.lbl{font-family:var(--mono);font-size:9.5px;letter-spacing:.2em;text-transform:uppercase;color:var(--faint);margin:0 0 13px}
.related ul{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:9px}
.related a{display:inline-block;font-family:var(--mono);font-size:11px;letter-spacing:.07em;border:1px solid var(--line);padding:8px 14px;border-radius:2px;color:var(--mute);background:none;transition:color .16s var(--ease),border-color .16s var(--ease)}
.related a:hover{color:var(--acc-txt);border-color:var(--acc);background:none}

/* ── pills ─────────────────────────────────────────────── */
.pills{display:flex;flex-wrap:wrap;gap:7px;margin:0;padding:0;list-style:none}
.pills li{font-family:var(--mono);font-size:10px;letter-spacing:.13em;text-transform:uppercase;color:var(--mute);border:1px solid var(--line);background:var(--panel);padding:7px 12px;border-radius:2px}

/* ── CTA band ──────────────────────────────────────────── */
.band{position:relative;overflow:hidden;background:var(--panel);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.band::before{content:"";position:absolute;inset:0;pointer-events:none;background:radial-gradient(620px 260px at 84% 120%, var(--acc-dim), transparent 70%)}
.band .inner{position:relative;padding:clamp(42px,6.5vh,70px) 0;display:grid;grid-template-columns:minmax(0,1fr) auto;gap:clamp(24px,4vw,56px);align-items:center}
@media(max-width:780px){.band .inner{grid-template-columns:1fr}}
.band h2{margin:0 0 11px;font-size:clamp(23px,2.9vw,32px)}
.band p{margin:0;font-size:16.5px;max-width:58ch}

.btn{display:inline-block;font-family:var(--mono);font-size:11.5px;letter-spacing:.16em;text-transform:uppercase;padding:15px 26px;border:1px solid var(--acc);color:var(--acc-txt);background:none;text-decoration:none;white-space:nowrap;border-radius:2px;transition:background .18s var(--ease),color .18s var(--ease),box-shadow .18s var(--ease)}
.btn:hover{background:var(--acc);color:var(--canvas);box-shadow:0 0 26px var(--acc-dim)}
.btn.solid{background:var(--acc);color:var(--canvas);font-weight:500}
.btn.solid:hover{box-shadow:0 0 30px var(--acc-dim);filter:brightness(1.08)}
.btn.ghost{border-color:var(--line-strong);color:var(--ink)}
.btn.ghost:hover{border-color:var(--acc);background:none;color:var(--acc-txt);box-shadow:none}
.btnrow{display:flex;flex-wrap:wrap;gap:12px;margin:28px 0 0}

/* ── footer ────────────────────────────────────────────── */
.foot{background:var(--panel);padding:clamp(46px,7vh,72px) 0 32px;font-size:15px;color:var(--mute);border-top:1px solid var(--line)}
.foot a{color:var(--body);background:none}
.foot a:hover{color:var(--acc-txt);background:none}
.foot .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(172px,1fr));gap:32px}
.foot h4{color:var(--ink);font-family:var(--mono);font-size:9.5px;letter-spacing:.2em;text-transform:uppercase;font-weight:400;margin:0 0 13px}
.foot ul{list-style:none;margin:0;padding:0;font-size:15px}
.foot li{margin:0 0 8px}
.foot .legal{margin-top:40px;padding-top:22px;border-top:1px solid var(--line);font-family:var(--mono);font-size:10px;letter-spacing:.07em;line-height:2;color:var(--faint);display:flex;flex-wrap:wrap;gap:4px 28px}

/* ── breadcrumbs ───────────────────────────────────────── */
.crumbs{font-family:var(--mono);font-size:10px;letter-spacing:.13em;text-transform:uppercase;color:var(--faint);padding:16px 0 0}
.crumbs a{color:var(--faint);background:none}
.crumbs a:hover{color:var(--acc-txt);background:none}

/* ── responsive ────────────────────────────────────────── */

/* Below this width the nav can't sit on one line beside the wordmark, so it
   drops to its own full-width row and scrolls sideways rather than wrapping
   into a four-line block that pushes the page content off-screen. */
@media(max-width:880px){
  .masthead .bar{flex-wrap:wrap;padding:12px 0 0;gap:12px}
  .toggle{order:2}  /* stays on the top row; the nav strip takes the row below */
  .nav{order:3;width:100%;flex-wrap:nowrap;overflow-x:auto;gap:20px;padding-bottom:11px;
       scrollbar-width:none;-ms-overflow-style:none;overscroll-behavior-x:contain}
  .nav::-webkit-scrollbar{display:none}
  .nav a{white-space:nowrap;flex:none;padding-bottom:2px}
}

@media(max-width:600px){
  body{font-size:16px}
  .nav{gap:17px}
  .nav a{font-size:10px;letter-spacing:.1em}
  .wordmark img{height:23px}
  .specrail .row{font-size:9px;gap:4px 16px}
  .titleblock dl{grid-template-columns:1fr}
  .titleblock dd{border-left:0;border-top:0;padding-top:0}
  .titleblock dt{padding-bottom:2px}
  .band .inner{padding:clamp(34px,5vh,52px) 0}
  .btnrow .btn{flex:1;text-align:center}
}

@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *{transition:none!important;animation:none!important}
}

@media print{
  .masthead,.specrail,.toc,.band,.progress,.skip,.toggle,.mediaband{display:none}
  body{background:#fff;color:#000;font-size:11pt}
  .hero::before,.band::before{display:none}
  /* the fundamentals guide gets printed for induction packs — keep figures
     legible on paper and stop them splitting across a page break */
  .fig,.dia,.defs,.calc,.tablewrap,.sec{break-inside:avoid;page-break-inside:avoid}
  .fig img{filter:none}
}