:root{
  --bg:#0b0d12;--bg2:#11141c;--panel:#151924;--panel2:#1b2030;--line:#252c3c;
  --line2:#38425a;--ink:#eef1f7;--dim:#98a2b8;--cyan:#3ee0d6;--cyan-d:#0f7a76;
  --amber:#ffb35c;--red:#ff8d7a;
  --sans:"Helvetica Neue",Helvetica,Arial,"Liberation Sans",sans-serif;
  --mono:ui-monospace,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--sans);
  font-size:17px;line-height:1.72;letter-spacing:.005em}
body.locked{overflow:hidden}
img,svg{display:block;max-width:100%}
a{color:var(--cyan);text-underline-offset:.2em}
a:hover{color:#fff}
button{font:inherit}
h1,h2,h3,h4{font-weight:700;line-height:1.14;letter-spacing:-.022em;margin:0 0 .6em}
h1{font-size:clamp(2.3rem,5.4vw,4.2rem)}
h2{font-size:clamp(1.5rem,2.8vw,2.35rem)}
h3{font-size:1.16rem}
p{margin:0 0 1.05em}
.shell{width:min(1220px,calc(100% - 40px));margin-inline:auto}
.narrow{width:min(780px,100%)}
.skip{position:fixed;top:-90px;left:14px;z-index:120;background:var(--cyan);
  color:#04231f;padding:11px 18px;font-weight:700;border-radius:3px}
.skip:focus{top:12px}
/* rail */
.rail{background:#05070b;border-bottom:1px solid var(--line);
  font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--dim)}
.rail .shell{display:flex;flex-wrap:wrap;gap:6px 22px;padding:9px 0;align-items:center}
.rail b{color:var(--cyan);font-weight:600}
.rail span:before{content:"/ ";color:var(--line2)}
/* header */
.masthead{position:sticky;top:0;z-index:60;background:rgba(11,13,18,.94);
  border-bottom:1px solid var(--line);backdrop-filter:blur(8px)}
.masthead .shell{display:flex;align-items:center;justify-content:space-between;height:70px;gap:20px}
.logo{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink);font-weight:700}
.logo em{font-family:var(--mono);font-style:normal;font-size:.66rem;letter-spacing:.12em;
  display:block;color:var(--cyan);text-transform:uppercase}
.logo-mark{width:34px;height:34px;flex:0 0 auto}
.logo span{font-size:1.02rem;letter-spacing:-.01em}
.burger{display:none;background:transparent;color:var(--ink);border:1px solid var(--line2);
  padding:8px 13px;border-radius:3px;font-family:var(--mono);font-size:.72rem;
  letter-spacing:.1em;text-transform:uppercase;cursor:pointer}
#mainnav{display:flex;gap:26px}
#mainnav a{color:var(--dim);text-decoration:none;font-size:.88rem;font-weight:600}
#mainnav a:hover,#mainnav a[aria-current=page]{color:var(--ink)}
#mainnav a[aria-current=page]{box-shadow:inset 0 -2px 0 var(--cyan)}
/* hero */
.hero{border-bottom:1px solid var(--line);padding:78px 0 66px;
  background:radial-gradient(120% 90% at 88% 0%,rgba(62,224,214,.13),transparent 60%),var(--bg)}
.hero-grid{display:grid;grid-template-columns:1.28fr .72fr;gap:60px;align-items:start}
.kicker{font-family:var(--mono);font-size:.72rem;letter-spacing:.14em;text-transform:uppercase;
  color:var(--cyan);display:block;margin-bottom:20px}
.hero p.lede{font-size:1.14rem;color:var(--dim);max-width:60ch}
.actions{display:flex;flex-wrap:wrap;gap:12px;margin:26px 0 24px}
.btn{display:inline-flex;align-items:center;gap:9px;background:var(--cyan);color:#04231f;
  border:1px solid var(--cyan);padding:12px 20px;border-radius:3px;font-weight:700;
  text-decoration:none;cursor:pointer}
.btn:hover{background:#fff;border-color:#fff;color:#04231f}
.btn.ghost{background:transparent;color:var(--ink);border-color:var(--line2)}
.btn.ghost:hover{border-color:var(--cyan);color:var(--cyan);background:transparent}
.freenote{border-left:2px solid var(--amber);padding:4px 0 4px 16px;color:var(--dim);
  font-size:.88rem;max-width:62ch}
.hero-art{border:1px solid var(--line);background:var(--panel);padding:22px}
.hero-art figcaption{font-family:var(--mono);font-size:.68rem;letter-spacing:.1em;
  text-transform:uppercase;color:var(--dim);margin-top:14px}
.stats{display:grid;grid-template-columns:repeat(3,1fr);border:1px solid var(--line);
  border-left:0;margin-top:22px}
.stats div{border-left:1px solid var(--line);padding:16px 18px}
.stats b{display:block;font-family:var(--mono);font-size:1.5rem;color:var(--cyan);letter-spacing:-.02em}
.stats span{font-size:.78rem;color:var(--dim)}
/* sections */
.band{padding:74px 0;border-bottom:1px solid var(--line)}
.band.alt{background:var(--bg2)}
.band.deep{background:var(--panel);}
.lead-grid{display:grid;grid-template-columns:.9fr 1.1fr;gap:56px}
.lead-grid p{color:var(--dim)}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:34px}
.cards article{border:1px solid var(--line);background:var(--panel);padding:26px}
.cards article b{font-family:var(--mono);font-size:.72rem;letter-spacing:.12em;color:var(--amber)}
.cards h3{margin:18px 0 10px}
.cards p{color:var(--dim);margin:0;font-size:.95rem}
.head-row{display:flex;justify-content:space-between;align-items:flex-end;gap:24px;flex-wrap:wrap}
.grid-links{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;background:var(--line);
  border:1px solid var(--line);margin-top:34px}
.grid-links a{background:var(--bg);padding:22px 24px;text-decoration:none;color:var(--ink);
  display:grid;gap:6px}
.grid-links a:hover{background:var(--panel2)}
.grid-links b{font-size:1.04rem}
.grid-links em{font-style:normal;color:var(--dim);font-size:.88rem}
.grid-links i{font-family:var(--mono);font-style:normal;font-size:.68rem;letter-spacing:.12em;
  text-transform:uppercase;color:var(--cyan)}
.steps{counter-reset:s;list-style:none;padding:0;margin:34px 0 0;
  display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
.steps li{counter-increment:s;border-top:2px solid var(--cyan);padding:16px 0 0;position:relative}
.steps li:before{content:"0" counter(s);font-family:var(--mono);font-size:.72rem;
  letter-spacing:.1em;color:var(--cyan)}
.steps strong{display:block;margin:8px 0 6px}
.steps p{color:var(--dim);font-size:.94rem;margin:0}
.formats{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--line);
  border:1px solid var(--line);margin-top:32px}
.formats div{background:var(--panel);padding:24px}
.formats strong{display:block;margin-bottom:8px}
.formats p{color:var(--dim);font-size:.92rem;margin:0}
.tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:20px}
.tags span{border:1px solid var(--line2);padding:6px 12px;font-family:var(--mono);
  font-size:.72rem;letter-spacing:.06em;color:var(--dim)}
/* page hero */
.phead{padding:66px 0 54px;border-bottom:1px solid var(--line);
  background:linear-gradient(180deg,var(--panel),var(--bg))}
.phead p.lede{color:var(--dim);font-size:1.1rem;max-width:70ch}
.meta{display:flex;flex-wrap:wrap;gap:8px 26px;margin-top:22px;font-family:var(--mono);
  font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--dim)}
.meta b{color:var(--ink);font-weight:600}
/* article */
.doc{display:grid;grid-template-columns:230px minmax(0,760px);gap:60px;
  justify-content:center;padding:56px 0 84px}
.toc{position:sticky;top:96px;align-self:start;border-top:2px solid var(--cyan);padding-top:16px}
.toc strong{font-family:var(--mono);font-size:.7rem;letter-spacing:.12em;text-transform:uppercase;
  color:var(--cyan);display:block;margin-bottom:10px}
.toc ol{list-style:none;counter-reset:t;padding:0;margin:0;font-size:.86rem}
.toc li{counter-increment:t;margin:0 0 7px}
.toc li:before{content:counter(t,decimal-leading-zero) " ";font-family:var(--mono);
  font-size:.72rem;color:var(--dim)}
.toc a{color:var(--dim);text-decoration:none}
.toc a:hover{color:var(--cyan)}
.prose>section{padding:0 0 30px;margin-bottom:30px;border-bottom:1px solid var(--line)}
.prose>section:last-of-type{border-bottom:0}
.prose h2{font-size:1.62rem}
.snum{font-family:var(--mono);font-size:.7rem;letter-spacing:.12em;text-transform:uppercase;
  color:var(--amber);display:block;margin-bottom:10px}
.prose p{color:#d4dae7}
.body-block{padding:56px 0 84px}
.body-block .prose{max-width:820px}
.body-block .prose h2{margin-top:12px}
/* tables */
.tw{overflow-x:auto;margin:26px 0;border:1px solid var(--line)}
table{width:100%;border-collapse:collapse;font-size:.9rem;background:var(--panel)}
caption{caption-side:top;text-align:left;padding:14px 16px;color:var(--dim);
  font-family:var(--mono);font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;
  border-bottom:1px solid var(--line)}
th,td{padding:12px 16px;text-align:left;vertical-align:top;border-top:1px solid var(--line)}
th{background:var(--panel2);font-size:.78rem;letter-spacing:.06em;text-transform:uppercase;color:var(--dim)}
tbody tr:nth-child(even) td{background:var(--bg2)}
/* lists, boxes */
.check{list-style:none;padding:0;margin:24px 0}
.check li{position:relative;padding:11px 0 11px 30px;border-bottom:1px solid var(--line);color:#d4dae7}
.check li:before{content:"";position:absolute;left:2px;top:19px;width:9px;height:9px;
  border:1px solid var(--cyan);border-top:0;border-right:0;transform:rotate(-45deg)}
.tl{list-style:none;counter-reset:z;padding:0;margin:26px 0}
.tl li{counter-increment:z;position:relative;padding:0 0 24px 46px}
.tl li:before{content:counter(z);position:absolute;left:0;top:0;width:30px;height:30px;
  display:grid;place-items:center;border:1px solid var(--cyan);color:var(--cyan);
  font-family:var(--mono);font-size:.78rem;border-radius:50%}
.tl li:not(:last-child):after{content:"";position:absolute;left:15px;top:32px;bottom:2px;
  width:1px;background:var(--line2)}
.tl strong{display:block;margin-bottom:4px}
.tl p{color:var(--dim);margin:0;font-size:.94rem}
.box{border:1px solid var(--line2);border-left:3px solid var(--amber);background:var(--panel);
  padding:24px;margin:26px 0}
.box h2,.box h3{font-size:1.18rem;margin-bottom:8px}
.box p:last-child{margin-bottom:0}
.rows{margin:26px 0;border-top:1px solid var(--line)}
.rows div{display:grid;grid-template-columns:200px 1fr;gap:24px;padding:16px 0;
  border-bottom:1px solid var(--line)}
.rows strong{color:var(--cyan)}
.rows p{margin:0;color:#d4dae7}
dl.lex{margin:26px 0;border-top:1px solid var(--line)}
dl.lex div{padding:16px 0;border-bottom:1px solid var(--line);display:grid;
  grid-template-columns:250px 1fr;gap:26px}
dl.lex dt{font-weight:700}
dl.lex dd{margin:0;color:#d4dae7}
details{border-bottom:1px solid var(--line);padding:15px 0}
summary{cursor:pointer;font-weight:600}
summary::marker{color:var(--cyan)}
details p{color:var(--dim);margin:10px 0 0}
.faqset{margin:0 0 40px}
.faqset>h2{padding-bottom:10px;border-bottom:2px solid var(--cyan)}
.next{display:grid;gap:8px;border:1px solid var(--line);background:var(--panel);
  padding:22px;margin-top:34px}
.next span{font-family:var(--mono);font-size:.68rem;letter-spacing:.12em;text-transform:uppercase;
  color:var(--dim)}
.sitemap-group{margin:0 0 34px}
.sitemap-group h2{font-size:1.3rem;padding-bottom:10px;border-bottom:1px solid var(--line)}
.sitemap-group ul{list-style:none;padding:0;margin:0}
.sitemap-group li{padding:12px 0;border-bottom:1px solid var(--line)}
.sitemap-group li p{margin:4px 0 0;color:var(--dim);font-size:.9rem}
/* calculator */
.calc{border:1px solid var(--line2);background:var(--panel);padding:clamp(20px,3vw,30px);margin:26px 0}
.calc-fields{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.calc label{font-size:.86rem;font-weight:600;display:block}
.calc input{display:block;width:100%;margin-top:8px;padding:11px 12px;background:var(--bg);
  color:var(--ink);border:1px solid var(--line2);border-radius:3px;font-family:var(--mono)}
.calc input:focus-visible{border-color:var(--cyan)}
.calc-out{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);
  border:1px solid var(--line);margin-top:22px}
.calc-out p{margin:0;padding:16px 18px;background:var(--bg2);display:grid;gap:4px}
.calc-out span{font-family:var(--mono);font-size:.68rem;letter-spacing:.1em;
  text-transform:uppercase;color:var(--dim)}
.calc-out strong{font-family:var(--mono);font-size:1.35rem;color:var(--cyan)}
.cform{border:1px solid var(--line2);background:var(--panel);padding:clamp(20px,3vw,30px);
  margin:26px 0;max-width:46em}
.cform h3{margin-top:0}
.cform-intro{color:var(--dim);font-size:.94rem}
.cform-fields{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin:18px 0}
.cform label{font-size:.86rem;font-weight:600;display:block}
.cform input[type=text],.cform input[type=email],.cform select,.cform textarea{display:block;
  width:100%;margin-top:8px;padding:11px 12px;background:var(--bg);color:var(--ink);
  border:1px solid var(--line2);font:inherit;font-size:.95rem}
.cform textarea{resize:vertical}
.cform input:focus-visible,.cform select:focus-visible,.cform textarea:focus-visible{
  border-color:var(--cyan)}
.cform-wide{margin-bottom:16px}
.cform-consent{display:flex;gap:12px;align-items:flex-start;font-size:.9rem;color:var(--dim);
  margin-bottom:16px}
.cform-consent input{margin:3px 0 0;flex:none;width:17px;height:17px;accent-color:var(--cyan)}
.cform-note{color:var(--dim);font-size:.88rem;border-left:2px solid var(--line2);padding-left:14px;
  margin-bottom:18px}
.calc-err{color:var(--red);font-weight:600;margin:14px 0 0}
.calc-formula{color:var(--dim);font-size:.86rem;margin-top:14px}
.calc-formula code{font-family:var(--mono);background:var(--bg);padding:.1em .4em;
  border:1px solid var(--line);display:inline-block;margin:3px 0}
code{font-family:var(--mono);font-size:.92em}
/* footer */
.foot{background:#05070b;border-top:1px solid var(--line);padding:60px 0 26px;color:var(--dim);
  font-size:.92rem}
.foot-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr;gap:48px}
.foot h2{font-family:var(--mono);font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;
  color:var(--cyan);margin-bottom:14px}
.foot a{display:block;color:var(--dim);text-decoration:none;padding:5px 0}
.foot a:hover{color:var(--ink)}
.foot-brand strong{display:block;color:var(--ink);font-size:1.1rem;margin-bottom:8px}
.foot-brand address{font-style:normal;margin-top:12px;line-height:1.7}
.foot-note{border:1px solid var(--line);padding:20px;margin-top:36px;font-size:.84rem}
.foot-note strong{color:var(--ink)}
.foot-base{display:flex;flex-wrap:wrap;gap:14px;justify-content:space-between;
  margin-top:22px;padding-top:18px;border-top:1px solid var(--line);
  font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase}
.linkbtn{background:none;border:0;color:var(--cyan);text-decoration:underline;cursor:pointer;
  font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;padding:0}
/* gate + consent */
.gate{position:fixed;inset:0;z-index:200;display:grid;place-items:center;padding:20px;
  background:rgba(4,6,10,.86);backdrop-filter:blur(12px)}
.gate[hidden],.consent[hidden]{display:none}
.gate-card{width:min(620px,100%);background:var(--bg2);border:1px solid var(--line2);
  border-top:3px solid var(--cyan);padding:clamp(24px,4vw,40px);max-height:90vh;overflow:auto}
.gate-card h2{font-size:1.7rem}
.gate-card p{color:#d4dae7;font-size:.96rem}
.gate-card ul{color:#d4dae7;font-size:.94rem;padding-left:20px}
.consent{position:fixed;left:18px;right:18px;bottom:18px;z-index:180;background:var(--bg2);
  border:1px solid var(--line2);padding:20px;display:flex;gap:26px;
  justify-content:space-between;align-items:center;flex-wrap:wrap}
.consent p{margin:6px 0 0;color:var(--dim);font-size:.86rem;max-width:74ch}
.consent strong{color:var(--ink)}
.consent-act{display:flex;gap:10px;align-items:center;flex-wrap:wrap;font-size:.86rem}
:focus-visible{outline:3px solid var(--amber);outline-offset:3px}
@media(max-width:960px){
  .hero-grid,.lead-grid{grid-template-columns:1fr;gap:34px}
  .cards,.formats,.grid-links,.steps,.calc-fields,.calc-out,.foot-grid{grid-template-columns:1fr}
  .doc{grid-template-columns:1fr;gap:30px;padding-top:34px}
  .toc{position:static}
  #mainnav{display:none;position:absolute;left:0;right:0;top:70px;flex-direction:column;
    gap:0;background:var(--bg2);border-bottom:1px solid var(--line);padding:10px 20px 18px}
  #mainnav.open{display:flex}
  #mainnav a{padding:11px 0;border-bottom:1px solid var(--line)}
  .burger{display:block}
  .rows div,dl.lex div{grid-template-columns:1fr;gap:6px}
  .band,.hero{padding:52px 0}
  .stats{grid-template-columns:1fr;border-left:1px solid var(--line)}
  .stats div{border-left:0;border-top:1px solid var(--line)}
  .stats div:first-child{border-top:0}
}
@media(prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;
  scroll-behavior:auto!important}}