*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd{margin:0}
ul[class],ol[class]{margin:0;padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit}
a{color:var(--teal)}

:root{
  --ink:#0B1B2B;
  --ink-2:#12293D;
  --paper:#F4F6F8;
  --mist:#E3FBF7;
  --cyan:#23E0D0;
  --teal:#0FA79B;
  --orange:#FF7A3D;
  --grid:#C7D1DA;
  --text:#0A1118;
  --muted:#6B7A88;
  --rail-w:268px;
  --bar-h:64px;
  --shell:1140px;
  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --line-dark:rgba(199,209,218,.16);
  --line-light:rgba(10,17,24,.14);
  --ease:cubic-bezier(.2,.7,.3,1);
}

:focus-visible{outline:2px solid var(--orange);outline-offset:3px}

body{
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.85;
  color:var(--text);
  background:var(--paper);
  padding-left:var(--rail-w);
  min-height:100vh;
}

h1,h2,h3,h4,h5{font-weight:900;line-height:1.18;letter-spacing:-.02em;color:var(--text)}
h1{font-size:clamp(34px,5vw,66px)}
h2{font-size:clamp(26px,3.2vw,40px)}
h3{font-size:clamp(19px,2vw,24px);letter-spacing:-.01em}
p{line-height:1.85}
strong{font-weight:700}

.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:-.01em}
.lead{font-size:clamp(17px,1.4vw,20px);line-height:1.8;color:var(--muted);max-width:60ch}
.eyebrow{display:inline-flex;align-items:center;gap:12px;font-family:var(--font-mono);font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--teal);margin-bottom:18px}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor}

/* ---------- skip link ---------- */
.skip-link{
  position:fixed;top:12px;left:12px;z-index:300;
  transform:translateY(-220%);
  background:var(--cyan);color:#04211F;
  padding:10px 18px;font-size:14px;font-weight:700;text-decoration:none;
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0)}
#main-content{scroll-margin-top:24px}

/* ---------- rail / header ---------- */
.scroll-progress{
  position:fixed;top:0;left:var(--rail-w);right:0;height:2px;
  z-index:90;pointer-events:none;background:rgba(35,224,208,.12);
}
.scroll-progress__bar{
  display:block;height:100%;width:100%;
  background:var(--orange);
  transform:scaleX(0);transform-origin:0 50%;
}

.rail{
  position:fixed;top:0;left:0;bottom:0;
  width:var(--rail-w);
  background:var(--ink);
  color:var(--paper);
  border-right:1px solid rgba(35,224,208,.2);
  z-index:80;
  display:flex;
}
.rail__inner{
  flex:1 1 auto;
  display:flex;flex-direction:column;
  gap:26px;
  padding:30px 22px 26px;
  overflow-y:auto;
  overscroll-behavior:contain;
}

.rail__brand{display:flex;align-items:center;gap:12px}
.rail__mark{
  position:relative;flex:0 0 auto;
  width:38px;height:38px;
  border:1px solid rgba(35,224,208,.5);
}
.rail__mark::before{
  content:"";position:absolute;left:8px;right:8px;top:18px;height:1.5px;
  background:var(--cyan);
}
.rail__mark::after{
  content:"";position:absolute;right:8px;top:14.25px;width:9px;height:9px;
  background:var(--orange);
}
.rail__wordmark{display:flex;flex-direction:column;gap:3px;min-width:0}
.rail__wordmark strong{font-size:17px;font-weight:900;letter-spacing:.01em;color:#fff;line-height:1.2}
.rail__motto{font-size:11px;letter-spacing:.16em;color:rgba(244,246,248,.5);line-height:1.4}

.rail-toggle{
  display:none;
  align-items:center;gap:10px;
  background:transparent;border:1px solid rgba(35,224,208,.4);
  color:var(--cyan);
  padding:8px 12px;cursor:pointer;font-size:13px;letter-spacing:.06em;
}
.rail-toggle__bars{position:relative;width:20px;height:14px}
.rail-toggle__bars::before,
.rail-toggle__bars::after{
  content:"";position:absolute;left:0;width:20px;height:2px;background:var(--cyan);
  transition:transform .2s var(--ease),top .2s var(--ease);
}
.rail-toggle__bars::before{top:0}
.rail-toggle__bars::after{top:12px}
.rail[data-open] .rail-toggle__bars::before{top:6px;transform:rotate(45deg)}
.rail[data-open] .rail-toggle__bars::after{top:6px;transform:rotate(-45deg)}

.rail__nav{display:flex;flex-direction:column;gap:22px}
.rail__list{display:flex;flex-direction:column}
.rail__link{
  position:relative;
  display:grid;grid-template-columns:26px 1fr;align-items:center;gap:8px;
  padding:11px 8px 11px 12px;
  color:rgba(244,246,248,.72);
  text-decoration:none;
  font-size:15px;line-height:1.5;
  border-top:1px solid rgba(199,209,218,.09);
  transition:color .16s var(--ease),background-color .16s var(--ease);
}
.rail__list li:last-child .rail__link{border-bottom:1px solid rgba(199,209,218,.09)}
.rail__link:hover{color:#fff;background:rgba(35,224,208,.07)}
.rail__link::before{
  content:"";position:absolute;left:0;top:12px;bottom:12px;width:2px;
  background:transparent;transition:background-color .16s var(--ease);
}
.rail__index{font-family:var(--font-mono);font-size:11px;letter-spacing:.04em;color:rgba(244,246,248,.38)}
.rail__link[aria-current="page"]{color:#fff}
.rail__link[aria-current="page"]::before{background:var(--orange)}
.rail__link[aria-current="page"] .rail__index{color:var(--cyan)}

.rail__cta{
  display:block;text-align:center;
  padding:12px 14px;
  background:var(--orange);border:1px solid var(--orange);color:#150F07;
  font-size:14px;font-weight:700;text-decoration:none;line-height:1.3;
  transition:background-color .16s var(--ease),color .16s var(--ease);
}
.rail__cta:hover{background:transparent;color:var(--orange)}

.rail__meta{
  display:flex;align-items:baseline;gap:10px;
  padding-top:18px;border-top:1px solid var(--line-dark);
}
.rail__version{font-family:var(--font-mono);font-size:24px;line-height:1;letter-spacing:-.02em;color:var(--cyan)}
.rail__version-note{font-size:11px;letter-spacing:.08em;color:rgba(244,246,248,.45)}
.rail__foot{
  margin-top:auto;display:flex;flex-direction:column;gap:5px;
  padding-top:16px;border-top:1px solid var(--line-dark);
  font-family:var(--font-mono);font-size:11px;line-height:1.7;letter-spacing:.02em;
  color:rgba(244,246,248,.42);
}
.rail__scrim{display:none}

/* ---------- footer ---------- */
.site-footer{
  position:relative;
  background:var(--ink);
  color:rgba(244,246,248,.72);
  padding:76px 0 0;
  border-top:1px solid rgba(35,224,208,.2);
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;right:0;height:3px;background:var(--cyan);
}
.site-footer::after{
  content:"";position:absolute;top:0;left:0;width:132px;height:3px;background:var(--orange);
}
.site-footer__inner{width:100%;max-width:var(--shell);margin:0 auto;padding:0 40px}
.footer__grid{
  display:grid;
  grid-template-columns:1.35fr .9fr 1.35fr 1fr;
  gap:44px 48px;
  align-items:start;
}
.footer-brand__name{font-size:22px;color:#fff;letter-spacing:-.01em}
.footer-brand__motto{
  margin-top:8px;font-size:12px;letter-spacing:.2em;
  color:var(--cyan);
}
.footer-brand__badge{
  display:inline-flex;align-items:center;gap:8px;
  margin-top:18px;padding:7px 12px;
  border:1px solid rgba(35,224,208,.32);
  font-size:11px;letter-spacing:.06em;color:rgba(244,246,248,.66);
}
.footer-brand__ver{font-family:var(--font-mono);font-size:15px;color:var(--cyan);letter-spacing:-.02em}
.footer-brand__note{margin-top:16px;font-size:13px;line-height:1.8;color:rgba(244,246,248,.5);max-width:30ch}

.footer-col__title{
  font-family:var(--font-mono);
  font-size:11px;font-weight:500;letter-spacing:.2em;
  color:rgba(244,246,248,.48);
  margin-bottom:16px;
}
.footer-col__list{display:flex;flex-direction:column;gap:9px;font-size:15px}
.footer-col__list a{
  color:rgba(244,246,248,.76);text-decoration:none;
  transition:color .14s var(--ease);
}
.footer-col__list a:hover{color:var(--cyan)}
.footer-col__list--meta{gap:14px}
.footer-contact{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 10px;font-size:14px;line-height:1.7}
.footer-contact__label{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:var(--teal);min-width:2.2em;
}
.footer-contact__value{color:rgba(244,246,248,.72)}
.copy-btn{
  background:transparent;border:1px solid rgba(199,209,218,.3);
  color:rgba(244,246,248,.6);font-size:11px;letter-spacing:.06em;
  padding:2px 8px;cursor:pointer;line-height:1.6;
  transition:border-color .14s var(--ease),color .14s var(--ease);
}
.copy-btn:hover{border-color:var(--cyan);color:var(--cyan)}
.copy-btn[data-copied]{border-color:var(--orange);color:var(--orange)}
.footer-col__link{
  display:inline-block;margin-top:16px;
  font-size:13px;letter-spacing:.04em;text-decoration:none;
  color:var(--orange);border-bottom:1px solid rgba(255,122,61,.45);padding-bottom:2px;
}
.footer-col__link:hover{color:#FFA375;border-bottom-color:#FFA375}

.footer-aside{
  position:sticky;bottom:24px;
  padding:20px 18px;
  background:var(--ink-2);
  border:1px solid rgba(35,224,208,.24);
}
.footer-aside__text{font-size:13px;line-height:1.8;color:rgba(244,246,248,.55)}
.footer-aside__btn{margin-top:16px;width:100%}
.footer-aside__link{
  display:block;margin-top:12px;text-align:center;
  font-size:13px;letter-spacing:.04em;text-decoration:none;
  color:rgba(244,246,248,.6);
}
.footer-aside__link:hover{color:var(--cyan)}

.footer__legal{
  margin-top:60px;padding:20px 0 30px;
  border-top:1px solid var(--line-dark);
  display:flex;flex-wrap:wrap;align-items:center;gap:8px 22px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.02em;
  color:rgba(244,246,248,.42);
}
.footer__legal-link{
  color:rgba(244,246,248,.55);text-decoration:none;
  border-bottom:1px solid rgba(199,209,218,.25);padding-bottom:1px;
}
.footer__legal-link:hover{color:var(--cyan);border-bottom-color:var(--cyan)}

/* ---------- generic layout ---------- */
.shell{width:100%;max-width:var(--shell);margin:0 auto;padding:0 40px}
.band{padding:88px 0;position:relative}
.band--ink{background:var(--ink);color:rgba(244,246,248,.78)}
.band--ink h1,.band--ink h2,.band--ink h3{color:#fff}
.band--ink .lead{color:rgba(244,246,248,.62)}
.band--ink .eyebrow{color:var(--cyan)}
.band--split{background:var(--ink-2);color:rgba(244,246,248,.78)}
.band--split h2,.band--split h3{color:#fff}
.band--split .eyebrow{color:var(--cyan)}
.band--paper{background:var(--paper)}
.band--mist{background:var(--mist)}

.grid{display:grid;gap:28px}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.split{display:grid;grid-template-columns:minmax(0,.85fr) minmax(0,1.15fr);gap:56px;align-items:start}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:13px 24px;border:1px solid transparent;
  font-family:inherit;font-size:15px;font-weight:700;line-height:1.2;
  text-decoration:none;cursor:pointer;
  transition:background-color .16s var(--ease),color .16s var(--ease),border-color .16s var(--ease);
}
.btn--solid{background:var(--orange);color:#150F07}
.btn--solid:hover{background:#FF9A66}
.btn--cyan{background:var(--cyan);color:#04211F}
.btn--cyan:hover{background:#7CEFE5}
.btn--ghost{background:transparent;border-color:rgba(35,224,208,.55);color:var(--cyan)}
.btn--ghost:hover{background:rgba(35,224,208,.12);border-color:var(--cyan)}
.btn--ink{background:var(--ink);color:var(--paper)}
.btn--ink:hover{background:var(--ink-2)}
.btn--sm{padding:9px 16px;font-size:13px}

/* ---------- breadcrumbs ---------- */
.crumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;
  color:var(--muted);
}
.crumbs a{color:var(--teal);text-decoration:none;border-bottom:1px solid rgba(15,167,155,.4);padding-bottom:1px}
.crumbs a:hover{color:var(--ink);border-bottom-color:var(--ink)}
.crumbs__sep{color:var(--grid)}
.crumbs [aria-current="page"]{color:var(--text)}

/* ---------- media ---------- */
.media{
  position:relative;display:block;margin:0;overflow:hidden;
  background:var(--ink-2);
  border:1px solid rgba(35,224,208,.2);
}
.media img{width:100%;height:100%;object-fit:cover}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--1x1{aspect-ratio:1/1}
.media--wide{aspect-ratio:21/9}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;opacity:.4;
  background-image:
    repeating-linear-gradient(90deg,rgba(199,209,218,.28) 0 1px,transparent 1px 72px),
    repeating-linear-gradient(0deg,rgba(199,209,218,.28) 0 1px,transparent 1px 72px);
}
.media__cap{
  margin-top:10px;font-family:var(--font-mono);font-size:12px;
  letter-spacing:.03em;color:var(--muted);
}

/* ---------- tabs ---------- */
.tabs{display:block}
.tabs__list{
  display:flex;gap:0;flex-wrap:nowrap;overflow-x:auto;
  border-bottom:1px solid var(--grid);
  scrollbar-width:thin;
}
.tabs__tab{
  appearance:none;background:transparent;border:0;
  border-bottom:2px solid transparent;
  padding:13px 20px;margin-bottom:-1px;
  font-family:inherit;font-size:15px;font-weight:700;line-height:1.4;
  color:var(--muted);cursor:pointer;white-space:nowrap;
  transition:color .16s var(--ease),border-color .16s var(--ease);
}
.tabs__tab:hover{color:var(--ink)}
.tabs__tab[aria-selected="true"]{color:var(--ink);border-bottom-color:var(--orange)}
.tabs__panel{padding:28px 0 0;animation:tabs-in .22s var(--ease) both}
.tabs__panel[hidden]{display:none}
@keyframes tabs-in{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---------- faq / details ---------- */
.faq{border-top:1px solid var(--grid)}
.faq__item{border-bottom:1px solid var(--grid)}
.faq__q{
  display:flex;align-items:baseline;justify-content:space-between;gap:18px;
  padding:18px 0;cursor:pointer;list-style:none;
  font-size:16px;font-weight:700;color:var(--text);
}
.faq__q::-webkit-details-marker{display:none}
.faq__q::after{
  content:"+";flex:0 0 auto;
  font-family:var(--font-mono);font-size:18px;color:var(--teal);
  transition:color .14s var(--ease);
}
.faq__item[open] .faq__q::after{content:"–";color:var(--orange)}
.faq__a{padding:0 0 22px;font-size:15px;line-height:1.85;color:var(--muted);max-width:66ch}

/* ---------- table ---------- */
.table{width:100%;border-collapse:collapse;font-size:15px;line-height:1.7}
.table caption{
  caption-side:top;text-align:left;padding-bottom:12px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--muted);
}
.table th,.table td{padding:14px 16px;text-align:left;border-bottom:1px solid var(--grid);vertical-align:top}
.table thead th{
  font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.08em;
  color:var(--muted);border-bottom:1px solid var(--ink);
}
.table tbody tr:hover{background:rgba(35,224,208,.08)}
.table td .mono{font-size:15px}

/* ---------- responsive ---------- */
@media (max-width:1100px){
  .footer__grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:40px}
  .footer-aside{position:static}
  .split{grid-template-columns:minmax(0,1fr);gap:36px}
}

@media (max-width:960px){
  body{padding-left:0;padding-top:var(--bar-h)}
  #main-content{scroll-margin-top:calc(var(--bar-h) + 20px)}
  .scroll-progress{left:0;top:var(--bar-h)}

.rail{
    top:0;left:0;right:0;bottom:auto;
    width:100%;height:var(--bar-h);
    flex-direction:row;align-items:center;
    border-right:0;border-bottom:1px solid rgba(35,224,208,.24);
  }
  .rail__inner{
    flex-direction:row;align-items:center;gap:12px;
    padding:0 16px;height:100%;overflow:visible;
  }
  .rail__mark{width:30px;height:30px}
  .rail__mark::before{left:6px;right:6px;top:14px}
  .rail__mark::after{right:6px;top:10.5px;width:8px;height:8px}
  .rail__wordmark strong{font-size:15px}
  .rail__motto{font-size:10px;letter-spacing:.1em}
  .rail-toggle{display:inline-flex;margin-left:auto}
  .rail__meta,.rail__foot{display:none}

.rail__nav{
    position:fixed;left:0;right:0;top:var(--bar-h);
    max-height:calc(100dvh - var(--bar-h));
    overflow-y:auto;overscroll-behavior:contain;
    background:var(--ink-2);
    padding:14px 16px 22px;
    border-bottom:1px solid rgba(35,224,208,.24);
    box-shadow:0 26px 48px rgba(4,10,18,.5);
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .22s var(--ease),transform .22s var(--ease),visibility .22s;
    z-index:2;
  }
  .rail[data-open] .rail__nav{opacity:1;visibility:visible;transform:none}
  .rail__link{font-size:16px;padding:14px 10px 14px 12px}
  .rail__cta{margin-top:6px}

.rail__scrim{
    display:block;position:fixed;inset:var(--bar-h) 0 0 0;
    margin:0;padding:0;border:0;background:rgba(5,12,20,.62);
    opacity:0;visibility:hidden;z-index:1;
    transition:opacity .22s var(--ease),visibility .22s;
  }
  .rail[data-open] .rail__scrim{opacity:1;visibility:visible}

.shell,.site-footer__inner{padding:0 22px}
  .band{padding:60px 0}
  .site-footer{padding-top:56px}
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .footer__legal{margin-top:44px}
}

@media (max-width:640px){
  body{font-size:16px}
  .shell,.site-footer__inner{padding:0 18px}
  .band{padding:48px 0}
  .footer__grid{grid-template-columns:minmax(0,1fr);gap:34px}
  .footer-brand__note{max-width:none}
  .tabs__tab{padding:12px 14px;font-size:14px}
  .table th,.table td{padding:12px 10px}
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .scroll-progress__bar{transform:none;width:0}
}