:root{
  --ink:#0B0F0D;
  --grass:#0F3D2E;
  --grass-2:#16543E;
  --graphite:#1A2420;
  --rule:#2E463C;
  --cyan:#38F2D0;
  --orange:#FF7A2F;
  --gold:#E8B75C;
  --paper:#E9F1EC;
  --muted:#9FC3B6;
  --font-sans:system-ui,-apple-system,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --wrap:1240px;
  --head-h:72px;
  --t:160ms ease;
  --pad-x:clamp(18px,4vw,44px);
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd,dt{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
table{border-collapse:collapse;width:100%}
summary{cursor:pointer}

body{
  min-height:100vh;
  background-color:var(--ink);
  background-image:
    repeating-linear-gradient(to right,rgba(46,70,60,.5) 0 1px,transparent 1px 108px),
    repeating-linear-gradient(to bottom,rgba(46,70,60,.5) 0 1px,transparent 1px 108px);
  background-attachment:fixed;
  color:var(--paper);
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
body.nav-open{overflow:hidden}

h1,h2,h3,h4{font-weight:900;line-height:1.15;letter-spacing:-.02em}
h1{font-size:clamp(30px,5vw,58px)}
h2{font-size:clamp(24px,3.2vw,36px)}
h3{font-size:clamp(19px,2.2vw,24px)}

p{max-width:38em}
strong{font-weight:700;color:var(--paper)}

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

/* ---------- layout ---------- */
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--pad-x)}
.band{padding-block:clamp(48px,7vw,96px)}
.band--grass{background:var(--grass);border-block:1px solid var(--rule)}
.band--ink{background:var(--ink)}
.grid{display:grid;gap:clamp(14px,2vw,26px)}
.grid--bento{grid-template-columns:repeat(12,minmax(0,1fr))}
.g-3{grid-column:span 3}
.g-4{grid-column:span 4}
.g-6{grid-column:span 6}
.g-8{grid-column:span 8}
.g-12{grid-column:span 12}
.sticky-rail{position:sticky;top:calc(var(--head-h) + 20px);align-self:start}

.section-head{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;
  gap:14px;padding-bottom:14px;border-bottom:1px solid var(--rule);margin-bottom:clamp(22px,3vw,38px);
}
.section-title{font-size:clamp(22px,3vw,34px);font-weight:900;letter-spacing:-.02em;line-height:1.15}

.eyebrow{
  display:flex;align-items:center;gap:10px;
  font-size:12px;font-weight:500;letter-spacing:.14em;color:var(--muted);
}
.eyebrow::before{content:"";width:18px;height:1px;background:var(--cyan);flex:none}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 9px;border:1px solid var(--rule);
  font-size:11px;font-weight:500;letter-spacing:.14em;color:var(--muted);
}
.tag--cyan{border-color:var(--cyan);color:var(--cyan)}
.tag--orange{border-color:var(--orange);color:var(--orange)}
.tag--gold{border-color:var(--gold);color:var(--gold)}

.num{font-family:var(--font-mono);font-weight:600;font-variant-numeric:tabular-nums;letter-spacing:-.01em}
.stat{display:grid;gap:6px}
.stat__v{
  font-family:var(--font-mono);font-weight:600;font-variant-numeric:tabular-nums;
  font-size:clamp(34px,6vw,62px);line-height:1;color:var(--cyan);letter-spacing:-.02em;
}
.stat__l{font-size:12px;letter-spacing:.14em;color:var(--muted)}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  padding:12px 22px;border:1px solid var(--rule);
  font-size:14px;font-weight:500;letter-spacing:.06em;color:var(--paper);
  background:transparent;
  transition:background var(--t),color var(--t),border-color var(--t);
}
.btn:hover,.btn:focus-visible{border-color:var(--cyan);color:var(--cyan)}
.btn--solid{background:var(--orange);border-color:var(--orange);color:var(--ink);font-weight:700}
.btn--solid:hover,.btn--solid:focus-visible{background:transparent;color:var(--orange)}
.btn--cyan{border-color:var(--cyan);color:var(--cyan)}
.btn--cyan:hover,.btn--cyan:focus-visible{background:var(--cyan);color:var(--ink)}

/* ---------- header ---------- */
.skip{
  position:fixed;left:14px;top:-120px;z-index:200;
  padding:10px 18px;background:var(--cyan);color:var(--ink);
  font-size:14px;font-weight:700;letter-spacing:.04em;
  transition:top 160ms ease;
}
.skip:focus{top:14px}

.site-head{
  position:sticky;top:0;z-index:80;
  background:var(--ink);
  border-bottom:1px solid var(--rule);
}
.head-inner{
  display:flex;align-items:center;gap:clamp(10px,1.6vw,26px);
  width:100%;padding:10px var(--pad-x);min-height:var(--head-h);
}
.brand{display:flex;align-items:center;gap:10px;min-width:0}
.brand__mark{
  display:inline-flex;align-items:center;justify-content:center;
  width:0;opacity:0;overflow:hidden;white-space:nowrap;
  font-family:var(--font-mono);font-weight:600;font-size:15px;letter-spacing:.08em;color:var(--cyan);
  transition:width 200ms ease,opacity 160ms ease;
}
.site-head[data-scrolled] .brand__mark{width:2.9rem;opacity:1}
.brand__text{
  display:grid;gap:1px;max-width:24ch;overflow:hidden;
  transition:max-width 220ms ease,opacity 140ms ease;
}
.site-head[data-scrolled] .brand__text{max-width:0;opacity:0}
.brand__word{font-size:20px;font-weight:900;line-height:1.1;letter-spacing:-.01em;white-space:nowrap}
.brand__sub{font-size:11px;font-weight:500;letter-spacing:.14em;color:var(--muted);line-height:1.4;white-space:nowrap}

.nav{margin-left:auto}
.nav__list{display:flex;align-items:center;gap:clamp(2px,1vw,16px)}
.nav__link{
  position:relative;display:block;padding:10px 8px;
  font-size:14px;font-weight:500;letter-spacing:.04em;color:var(--muted);
  transition:color var(--t);
}
.nav__link::after{
  content:"";position:absolute;left:8px;right:8px;bottom:4px;height:1px;
  background:var(--cyan);transform:scaleX(0);transform-origin:left;
  transition:transform var(--t);
}
.nav__link:hover,.nav__link:focus-visible{color:var(--cyan)}
.nav__link:hover::after,.nav__link:focus-visible::after{transform:scaleX(1)}
.nav__link[aria-current="page"]{color:var(--paper)}
.nav__link[aria-current="page"]::after{transform:scaleX(1);background:var(--orange)}

.head-cta{
  display:inline-flex;align-items:center;
  padding:9px 16px;border:1px solid var(--orange);color:var(--orange);
  font-size:13px;font-weight:500;letter-spacing:.08em;white-space:nowrap;
  transition:background var(--t),color var(--t);
}
.head-cta:hover,.head-cta:focus-visible{background:var(--orange);color:var(--ink)}

.navbtn{
  display:none;align-items:center;gap:8px;
  padding:9px 12px;border:1px solid var(--rule);color:var(--paper);
  font-size:12px;font-weight:500;letter-spacing:.14em;
  transition:border-color var(--t),color var(--t);
}
.navbtn:hover,.navbtn:focus-visible{border-color:var(--cyan);color:var(--cyan)}
.navbtn__bars{position:relative;display:block;width:16px;height:9px;flex:none}
.navbtn__bars::before,.navbtn__bars::after{
  content:"";position:absolute;left:0;right:0;height:2px;background:currentColor;
  transition:top var(--t),bottom var(--t),transform var(--t);
}
.navbtn__bars::before{top:0}
.navbtn__bars::after{bottom:0}
.site-head[data-open] .navbtn__bars::before{top:3.5px;transform:rotate(45deg)}
.site-head[data-open] .navbtn__bars::after{bottom:3.5px;transform:rotate(-45deg)}

.progress{height:2px;background:transparent;overflow:hidden}
.progress__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--cyan),var(--orange));
  transition:width 90ms linear;
}

.head-scrim{
  position:fixed;inset:0;z-index:70;
  background:rgba(11,15,13,.7);
  opacity:0;visibility:hidden;
  transition:opacity 200ms ease,visibility 200ms;
}
.site-head[data-open] .head-scrim{opacity:1;visibility:visible}

/* ---------- footer ---------- */
.site-foot{
  margin-top:clamp(48px,8vw,100px);
  background:var(--grass);
  border-top:1px solid var(--rule);
  color:var(--paper);
}
.foot-grid{
  display:grid;gap:clamp(28px,4vw,56px);
  grid-template-columns:1fr 1.15fr 1.3fr;
  padding-block:clamp(44px,6vw,76px);
}
.foot-col > .eyebrow{margin-bottom:18px}
.foot-links{display:grid;gap:10px;font-size:14px}
.foot-links a{
  display:inline-flex;align-items:center;gap:8px;color:var(--muted);
  transition:color var(--t);
}
.foot-links a::before{
  content:"";display:block;width:0;height:1px;background:var(--cyan);
  transition:width var(--t);
}
.foot-links a:hover,.foot-links a:focus-visible{color:var(--cyan)}
.foot-links a:hover::before,.foot-links a:focus-visible::before{width:14px}

.foot-meta{display:grid;grid-template-columns:auto 1fr;gap:10px 16px;font-size:14px}
.foot-meta dt{font-size:12px;letter-spacing:.12em;color:var(--muted);padding-top:2px}
.foot-meta dd{color:var(--paper);word-break:break-word}
.foot-note{margin-top:14px;font-size:13px;line-height:1.7;color:var(--muted);max-width:36em}
.foot-icp{
  margin-top:18px;font-family:var(--font-mono);font-size:13px;
  letter-spacing:.04em;color:var(--muted);
  border-top:1px solid var(--rule);padding-top:14px;
}
.foot-base{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px;
  padding-block:20px;border-top:1px solid var(--rule);
  font-size:12px;letter-spacing:.06em;color:var(--muted);
}
.foot-base ul{display:flex;flex-wrap:wrap;gap:18px}
.foot-base a{color:var(--muted);border-bottom:1px solid var(--rule);transition:color var(--t),border-color var(--t)}
.foot-base a:hover,.foot-base a:focus-visible{color:var(--cyan);border-color:var(--cyan)}

/* ---------- content basics ---------- */
.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:12px;letter-spacing:.08em;color:var(--muted)}
.crumbs li{display:flex;align-items:center;gap:8px}
.crumbs li + li::before{content:"/";color:var(--rule)}
.crumbs a{color:var(--muted);border-bottom:1px solid transparent;transition:color var(--t),border-color var(--t)}
.crumbs a:hover,.crumbs a:focus-visible{color:var(--cyan);border-color:var(--cyan)}

.prose{max-width:38em}
.prose p{margin-bottom:1.1em}
.prose p:last-child{margin-bottom:0}
.prose h2{font-size:clamp(22px,2.6vw,30px);margin:1.6em 0 .55em}
.prose h3{margin:1.4em 0 .5em}
.prose ul{display:grid;gap:.5em;margin-bottom:1.1em}
.prose li{position:relative;padding-left:1.15em}
.prose li::before{content:"";position:absolute;left:0;top:.72em;width:9px;height:1px;background:var(--cyan)}
.prose a{color:var(--cyan);border-bottom:1px solid var(--rule);transition:border-color var(--t)}
.prose a:hover{border-color:var(--cyan)}

.slab{
  position:relative;
  background:var(--graphite);
  border:1px solid var(--rule);
  padding:clamp(18px,2.4vw,30px);
}
.slab--grass{background:var(--grass)}
.slab--tight{padding:clamp(14px,1.8vw,20px)}
.slab--stack{box-shadow:8px 8px 0 0 rgba(46,70,60,.6)}
.slab__label{
  position:absolute;top:-1px;left:-1px;
  padding:4px 11px;background:var(--ink);border:1px solid var(--rule);
  font-size:11px;font-weight:500;letter-spacing:.14em;color:var(--muted);
}

.media{
  position:relative;overflow:hidden;
  background:var(--graphite);border:1px solid var(--rule);
  aspect-ratio:16/9;
}
.media > img,.media > svg,.media > video{width:100%;height:100%;object-fit:cover}
.media--21x9{aspect-ratio:21/9}
.media--4x3{aspect-ratio:4/3}
.media--3x2{aspect-ratio:3/2}
.media--1x1{aspect-ratio:1/1}
.media--3x4{aspect-ratio:3/4}
.media--tall{aspect-ratio:2/3}
.media--shade::after{
  content:"";position:absolute;inset:0;z-index:1;
  background:linear-gradient(180deg,rgba(11,15,13,0) 38%,rgba(11,15,13,.86) 100%);
}
.media--night::before{
  content:"";position:absolute;inset:0;z-index:1;
  background:linear-gradient(140deg,rgba(15,61,46,.6),rgba(11,15,13,.32));
}
.media__cap{
  position:absolute;left:0;bottom:0;z-index:2;
  padding:8px 14px;background:var(--ink);
  border-top:1px solid var(--rule);border-right:1px solid var(--rule);
  font-size:11px;letter-spacing:.14em;color:var(--muted);
}

.rail{position:relative;padding-left:28px;display:grid;gap:22px}
.rail::before{
  content:"";position:absolute;left:7px;top:8px;bottom:8px;width:1px;
  background:linear-gradient(180deg,var(--cyan),var(--rule) 38%,var(--rule));
}
.rail__item{position:relative}
.rail__item::before{
  content:"";position:absolute;left:-28px;top:7px;
  width:15px;height:15px;background:var(--ink);border:1px solid var(--rule);
}
.rail__item--now::before{background:var(--orange);border-color:var(--orange);box-shadow:0 0 0 4px rgba(255,122,47,.14)}
.rail__item--key::before{background:var(--gold);border-color:var(--gold)}

.fold{border-top:1px solid var(--rule)}
.fold:last-of-type{border-bottom:1px solid var(--rule)}
.fold > summary{
  position:relative;list-style:none;padding:18px 46px 18px 0;
  font-size:17px;font-weight:500;color:var(--paper);
  transition:color var(--t);
}
.fold > summary::-webkit-details-marker{display:none}
.fold > summary::after{
  content:"";position:absolute;right:8px;top:50%;
  width:11px;height:11px;border-right:1px solid var(--muted);border-bottom:1px solid var(--muted);
  transform:translateY(-70%) rotate(45deg);
  transition:transform var(--t),border-color var(--t);
}
.fold[open] > summary::after{transform:translateY(-30%) rotate(-135deg);border-color:var(--cyan)}
.fold > summary:hover,.fold > summary:focus-visible{color:var(--cyan)}
.fold__body{padding:0 0 24px;color:var(--muted);max-width:40em;font-size:15px}

.dtable{width:100%;font-size:14px}
.dtable th,.dtable td{text-align:left;padding:12px 14px;border-bottom:1px solid var(--rule);vertical-align:top}
.dtable thead th{font-size:11px;font-weight:500;letter-spacing:.14em;color:var(--muted)}
.dtable tbody td{color:var(--paper)}
.dtable tbody tr{transition:background var(--t)}
.dtable tbody tr:hover{background:var(--grass)}
.dtable .num{color:var(--cyan)}

.toc{display:grid;gap:2px;font-size:13px}
.toc a{
  display:flex;align-items:center;gap:10px;
  padding:8px 10px;border-left:1px solid var(--rule);color:var(--muted);
  transition:color var(--t),border-color var(--t),background var(--t);
}
.toc a:hover,.toc a:focus-visible{color:var(--cyan);border-color:var(--cyan)}
.toc a[aria-current="true"]{color:var(--paper);border-color:var(--orange);background:var(--grass)}

.totop{
  position:fixed;right:18px;bottom:18px;z-index:60;
  padding:10px 14px;border:1px solid var(--rule);background:var(--ink);color:var(--muted);
  font-size:12px;font-weight:500;letter-spacing:.14em;
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity 180ms ease,visibility 180ms,transform 180ms ease,color var(--t),border-color var(--t);
}
.totop[data-show]{opacity:1;visibility:visible;transform:none}
.totop:hover,.totop:focus-visible{color:var(--cyan);border-color:var(--cyan)}

/* ---------- responsive ---------- */
@media (max-width:1080px){
  .g-3{grid-column:span 6}
  .g-4{grid-column:span 6}
  .g-8{grid-column:span 12}
}
@media (max-width:900px){
  :root{--head-h:64px}
  .site-head{position:sticky}
  .head-inner{gap:10px}
  .head-cta{margin-left:auto;padding:8px 12px;font-size:12px;letter-spacing:.06em}
  .navbtn{display:inline-flex}
  .nav{
    position:fixed;top:0;right:0;bottom:0;z-index:90;
    width:min(84vw,340px);margin:0;
    padding:calc(var(--head-h) + 22px) 22px 34px;
    background:var(--grass);border-left:1px solid var(--rule);
    transform:translateX(101%);overflow-y:auto;
    transition:transform 220ms ease;
  }
  .site-head[data-open] .nav{transform:translateX(0)}
  .nav__list{counter-reset:navno;display:block}
  .nav__item{counter-increment:navno}
  .nav__item + .nav__item{border-top:1px solid var(--rule)}
  .nav__link{
    display:flex;align-items:center;gap:14px;
    padding:16px 12px;font-size:17px;font-weight:500;color:var(--paper);
  }
  .nav__link::before{
    content:counter(navno,decimal-leading-zero);
    flex:none;width:2.2ch;
    font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:var(--muted);
  }
  .nav__link::after{
    left:0;right:auto;top:50%;bottom:auto;
    width:3px;height:24px;background:var(--orange);
    transform:translateY(-50%) scaleY(0);transform-origin:center;
  }
  .nav__link:hover::after,.nav__link:focus-visible::after,
  .nav__link[aria-current="page"]::after{transform:translateY(-50%) scaleY(1)}
  .nav__link[aria-current="page"]::before{color:var(--orange)}
  .foot-grid{grid-template-columns:1fr 1fr}
  .foot-grid > .foot-col:last-child{grid-column:1 / -1}
}
@media (max-width:640px){
  body{font-size:16px}
  .grid--bento{grid-template-columns:repeat(6,minmax(0,1fr))}
  .grid--bento > *{grid-column:span 6}
  .sticky-rail{position:static}
  .foot-grid{grid-template-columns:1fr}
  .foot-base{flex-direction:column;align-items:flex-start}
  .dtable,.dtable thead,.dtable tbody,.dtable tr,.dtable th,.dtable td{display:block}
  .dtable thead{display:none}
  .dtable tr{border-bottom:1px solid var(--rule);padding:10px 0}
  .dtable td{border:0;padding:5px 0;display:flex;justify-content:space-between;gap:16px}
  .dtable td::before{
    content:attr(data-label);
    flex:none;font-size:12px;letter-spacing:.1em;color:var(--muted);
  }
}
@media (max-width:400px){
  .navbtn__label{display:none}
  .brand__sub{display:none}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    scroll-behavior:auto !important;
  }
}