:root{
  --ink:#050F22;
  --ink-2:#0A1B36;
  --line:#16355F;
  --cyan:#26E3D8;
  --cyan-soft:#8FF6EF;
  --signal:#FF7A1A;
  --text:#EAF2FF;
  --muted:#93A7C6;
  --ok:#3BE08C;
  --warn:#FFC24B;
  --cut:14px;
  --cut-corner:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
  --sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC","Noto Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  --mono:"JetBrains Mono","SFMono-Regular","Cascadia Code",Consolas,"Noto Sans Mono","Sarasa Mono SC",ui-monospace,monospace;
  --shell:1280px;
  --pad:clamp(18px,4vw,48px);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  font-family:var(--sans);
  font-size:16px;
  line-height:1.75;
  color:var(--text);
  background-color:var(--ink);
  background-image:
    radial-gradient(900px 520px at 88% -8%,rgba(22,53,95,.75),transparent 65%),
    linear-gradient(rgba(38,227,216,.028) 1px,transparent 1px),
    linear-gradient(90deg,rgba(38,227,216,.028) 1px,transparent 1px);
  background-size:auto,46px 46px,46px 46px;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
h1,h2,h3,h4{font-weight:800;letter-spacing:.04em;line-height:1.18;margin:0 0 .5em;color:var(--text)}
h1{font-size:clamp(30px,5vw,56px)}
h2{font-size:clamp(21px,2.8vw,32px)}
h3{font-size:clamp(17px,1.9vw,22px)}
p{margin:0 0 1em}
ul,ol{padding-left:1.2em}
a{color:var(--cyan);text-decoration:none}
a:hover{color:var(--cyan-soft)}
img{max-width:100%;height:auto;display:block}
button{font:inherit}
:where(a,button,[tabindex]):focus-visible{outline:2px solid var(--cyan-soft);outline-offset:3px;border-radius:2px}
.btn:focus-visible,.nav-toggle:focus-visible,.fold__trigger:focus-visible{outline-offset:-3px}

/* skip link */
.skip-link{position:fixed;left:14px;top:-80px;z-index:300;display:inline-block;padding:10px 18px;background:var(--cyan);color:#04121F;font-weight:700;letter-spacing:.06em;text-decoration:none;transition:top .18s ease}
.skip-link:focus{top:14px;color:#04121F}

/* ---------- header ---------- */
.site-header{
  position:sticky;top:0;z-index:80;
  background:linear-gradient(180deg,rgba(5,15,34,.97) 0%,rgba(10,27,54,.94) 100%);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(12px);
}
.progress-rail{position:absolute;left:0;right:0;bottom:-1px;height:2px;background:rgba(22,53,95,.6);overflow:hidden}
.progress-rail__fill{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--cyan) 0%,var(--cyan-soft) 60%,var(--signal) 100%);transition:width .12s linear}
.header-inner{
  display:flex;align-items:center;gap:clamp(10px,2vw,26px);
  max-width:var(--shell);margin:0 auto;padding:12px var(--pad);
  position:relative;z-index:2;
}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);position:relative;z-index:3}
.brand:hover{color:var(--text)}
.brand__glyph{
  display:grid;place-items:center;width:34px;height:34px;flex:0 0 auto;
  font-family:var(--mono);font-size:16px;font-weight:700;color:#04121F;
  background:linear-gradient(135deg,var(--cyan-soft),var(--cyan));
  clip-path:var(--cut-corner);
}
.brand__word{font-size:19px;font-weight:800;letter-spacing:.14em;line-height:1}
.brand__ver{
  font-family:var(--mono);font-size:11px;font-weight:600;letter-spacing:.1em;line-height:1;
  color:var(--cyan);padding:4px 7px;border:1px solid rgba(38,227,216,.45);
  background:rgba(38,227,216,.08);white-space:nowrap;
}
.header-meta{
  display:flex;align-items:center;gap:8px;margin:0;
  font-family:var(--mono);font-size:11.5px;letter-spacing:.1em;color:var(--muted);white-space:nowrap;
}
.site-nav{margin-left:auto;display:flex;align-items:center;gap:16px}
.site-nav__list{display:flex;align-items:center;gap:2px;margin:0;padding:0;list-style:none}
.site-nav__link{
  position:relative;display:inline-block;padding:9px 11px;
  font-size:14px;letter-spacing:.05em;color:var(--muted);text-decoration:none;
  transition:color .16s ease,background .16s ease;
}
.site-nav__link:hover{color:var(--text);background:rgba(38,227,216,.08)}
.site-nav__link[aria-current="page"]{
  color:var(--text);
  background:linear-gradient(180deg,rgba(38,227,216,.18),rgba(38,227,216,.04));
}
.site-nav__link[aria-current="page"]::after{
  content:"";position:absolute;left:11px;right:11px;bottom:2px;height:2px;background:var(--signal);
}
.site-nav__cta{margin-left:6px}
.nav-toggle{
  display:none;align-items:center;gap:9px;margin-left:auto;
  padding:9px 13px;cursor:pointer;
  background:rgba(22,53,95,.6);border:1px solid var(--line);color:var(--text);
  font-family:var(--mono);font-size:12px;letter-spacing:.12em;
  clip-path:var(--cut-corner);position:relative;z-index:3;
}
.nav-toggle__bars{position:relative;display:block;width:16px;height:10px}
.nav-toggle__bars::before,.nav-toggle__bars::after{
  content:"";position:absolute;left:0;right:0;height:2px;background:var(--cyan);
  transition:transform .2s ease,background .2s ease;
}
.nav-toggle__bars::before{top:0}
.nav-toggle__bars::after{bottom:0}
.site-header[data-open] .nav-toggle__bars::before{transform:translateY(4px) rotate(45deg);background:var(--signal)}
.site-header[data-open] .nav-toggle__bars::after{transform:translateY(-4px) rotate(-45deg);background:var(--signal)}
.index-strip{
  display:flex;align-items:center;gap:20px;
  max-width:var(--shell);margin:0 auto;padding:5px var(--pad) 7px;
  font-family:var(--mono);font-size:11.5px;letter-spacing:.09em;color:var(--muted);
  border-top:1px solid rgba(22,53,95,.65);
}
.index-strip__tag{position:relative;padding-left:10px;color:var(--cyan)}
.index-strip__tag::before{content:"";position:absolute;left:0;top:50%;width:3px;height:12px;transform:translateY(-50%);background:var(--signal)}
.index-strip__link{color:var(--muted);text-decoration:none;border-bottom:1px dashed rgba(147,167,198,.42);padding-bottom:1px;transition:color .16s,border-color .16s}
.index-strip__link:hover{color:var(--cyan-soft);border-bottom-color:var(--cyan)}
.index-strip__code{margin-left:auto;color:rgba(147,167,198,.7)}

/* ---------- footer ---------- */
.site-footer{
  position:relative;margin-top:clamp(48px,8vw,96px);
  border-top:1px solid var(--line);
  background:linear-gradient(180deg,rgba(10,27,54,.55) 0%,rgba(5,15,34,.98) 45%);
}
.site-footer::before{
  content:"";position:absolute;top:-1px;left:0;width:min(260px,40%);height:1px;
  background:linear-gradient(90deg,var(--cyan),transparent);
}
.footer-shell{max-width:var(--shell);margin:0 auto;padding:clamp(30px,5vw,56px) var(--pad) 24px}
.footer-top{display:grid;gap:clamp(24px,4vw,48px);grid-template-columns:minmax(220px,1fr) minmax(0,1.7fr)}
.footer-brand{display:grid;gap:10px;align-content:start;justify-items:start}
.brand--footer{gap:9px}
.brand--footer .brand__word{font-size:17px;letter-spacing:.12em}
.brand--footer .brand__glyph{width:30px;height:30px;font-size:14px}
.footer-tagline{margin:0;max-width:34ch;font-size:14px;line-height:1.75;color:var(--muted)}
.footer-ver{margin:0;font-family:var(--mono);font-size:11.5px;letter-spacing:.08em;color:var(--cyan)}
.footer-cols{display:grid;gap:clamp(20px,3vw,36px);grid-template-columns:repeat(3,minmax(0,1fr))}
.footer-col__title{
  margin:0 0 12px;padding-bottom:8px;border-bottom:1px solid var(--line);
  font-family:var(--mono);font-size:11.5px;font-weight:600;letter-spacing:.16em;color:var(--cyan);
}
.footer-links{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.footer-link{color:var(--muted);font-size:14px;text-decoration:none;transition:color .16s ease}
.footer-link:hover{color:var(--cyan-soft)}
.footer-contact{list-style:none;margin:0;padding:0;display:grid;gap:9px;font-size:13.5px;color:var(--muted)}
.footer-contact li{display:flex;gap:9px;line-height:1.6}
.footer-contact__key{
  flex:0 0 auto;min-width:36px;font-family:var(--mono);font-size:11px;letter-spacing:.1em;
  color:rgba(147,167,198,.8);padding-top:2px;
}
.footer-base{
  display:flex;flex-wrap:wrap;gap:10px 24px;justify-content:space-between;align-items:center;
  margin-top:clamp(24px,4vw,40px);padding-top:16px;
  border-top:1px dashed rgba(22,53,95,.9);
  font-family:var(--mono);font-size:11.5px;letter-spacing:.05em;color:rgba(147,167,198,.85);
}
.footer-legal,.footer-copy{margin:0}

/* ---------- shared page scaffolding ---------- */
.container{width:100%;max-width:var(--shell);margin-inline:auto;padding-inline:var(--pad)}
.container--narrow{max-width:880px}
.page-main{padding-block:clamp(22px,3.5vw,48px) clamp(40px,7vw,88px)}
.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:0;margin:0 0 20px;padding:0;list-style:none;font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--muted)}
.crumbs li{display:flex;align-items:center;gap:8px}
.crumbs li+li::before{content:"/";color:var(--line);margin-right:8px}
.crumbs a{color:var(--muted);border-bottom:1px solid transparent;transition:color .16s,border-color .16s}
.crumbs a:hover{color:var(--cyan);border-bottom-color:var(--cyan)}
.crumbs [aria-current="page"]{color:var(--cyan-soft)}
.prose{max-width:66ch}
.prose h2,.prose h3{margin-top:1.6em}
.prose ul,.prose ol{margin:0 0 1em;padding-left:1.3em}
.prose li{margin-bottom:.35em}
.prose strong{color:var(--cyan-soft);font-weight:700}

/* buttons */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 18px;border:1px solid var(--line);border-radius:0;
  background:rgba(22,53,95,.65);color:var(--text);
  font-size:14px;font-weight:700;letter-spacing:.06em;line-height:1.2;text-decoration:none;cursor:pointer;
  clip-path:var(--cut-corner);
  transition:background .18s ease,color .18s ease,transform .18s ease,border-color .18s ease;
}
.btn:hover{background:rgba(38,227,216,.16);color:var(--text);border-color:rgba(38,227,216,.55);transform:translateY(-1px)}
.btn--signal{
  background:linear-gradient(135deg,#FF9642 0%,var(--signal) 70%);
  border-color:var(--signal);color:#0B1220;
}
.btn--signal:hover{background:linear-gradient(135deg,#FFA65C 0%,#FF8A32 70%);color:#0B1220;border-color:#FFB070}
.btn--ghost{background:transparent;border-color:rgba(38,227,216,.45);color:var(--cyan-soft)}
.btn--ghost:hover{background:rgba(38,227,216,.12);color:var(--cyan-soft)}

/* bento grid */
.bento{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(12px,1.6vw,20px)}
.bento>*{grid-column:span 12;min-width:0}
@media (min-width:900px){
  .bento .span-3{grid-column:span 3}
  .bento .span-4{grid-column:span 4}
  .bento .span-5{grid-column:span 5}
  .bento .span-6{grid-column:span 6}
  .bento .span-7{grid-column:span 7}
  .bento .span-8{grid-column:span 8}
  .bento .span-9{grid-column:span 9}
}

/* panel */
.panel{
  position:relative;
  padding:clamp(18px,2.4vw,28px);
  border:1px solid var(--line);
  background:linear-gradient(160deg,rgba(22,53,95,.6) 0%,rgba(10,27,54,.92) 68%);
  clip-path:var(--cut-corner);
}
.panel--glow::before{
  content:"";position:absolute;left:0;right:0;top:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(38,227,216,.85),transparent);
}
.section-head{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:8px 16px;
  margin:0 0 clamp(14px,2vw,22px);padding-bottom:10px;
  border-bottom:1px solid var(--line);
}
.section-head h2{margin:0}
.section-head__index{font-family:var(--mono);font-size:12px;letter-spacing:.14em;color:var(--signal)}

/* horizontal index rail */
.index-rail{
  display:flex;gap:8px;margin:0;padding:2px 0 14px;list-style:none;
  overflow-x:auto;scroll-snap-type:x proximity;-webkit-overflow-scrolling:touch;
}
.index-rail::-webkit-scrollbar{height:6px}
.index-rail::-webkit-scrollbar-track{background:rgba(22,53,95,.4)}
.index-rail::-webkit-scrollbar-thumb{background:var(--line);border-radius:99px}
.index-rail>*{flex:0 0 auto;scroll-snap-align:start}
.index-rail a,.index-rail__item{
  display:inline-flex;align-items:center;gap:8px;padding:9px 14px;
  font-family:var(--mono);font-size:12.5px;letter-spacing:.06em;color:var(--muted);
  text-decoration:none;border:1px solid var(--line);background:rgba(10,27,54,.72);
  transition:color .16s,border-color .16s,background .16s;
}
.index-rail a:hover{color:var(--text);border-color:rgba(38,227,216,.6);background:rgba(38,227,216,.1)}

/* tags + dots */
.tag{
  display:inline-flex;align-items:center;gap:6px;padding:3px 9px;
  border:1px solid var(--line);background:rgba(10,27,54,.75);
  font-family:var(--mono);font-size:11.5px;letter-spacing:.09em;line-height:1.5;color:var(--muted);
}
.tag--ok{color:var(--ok);border-color:rgba(59,224,140,.42);background:rgba(59,224,140,.08)}
.tag--warn{color:var(--warn);border-color:rgba(255,194,75,.42);background:rgba(255,194,75,.08)}
.tag--signal{color:#0B1220;background:var(--signal);border-color:var(--signal);font-weight:700}
.dot{display:inline-block;width:7px;height:7px;flex:0 0 auto;border-radius:50%;background:var(--cyan);box-shadow:0 0 0 3px rgba(38,227,216,.16)}
.dot--live{background:var(--ok);box-shadow:0 0 0 3px rgba(59,224,140,.18);animation:pulse 2.6s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.45}}

/* fold groups */
.fold{display:grid;gap:10px}
.fold__item{border:1px solid var(--line);background:rgba(10,27,54,.75);clip-path:var(--cut-corner)}
.fold__trigger{
  display:flex;width:100%;align-items:center;justify-content:space-between;gap:16px;
  padding:15px 18px;background:none;border:0;color:var(--text);
  font-family:var(--sans);font-size:15.5px;font-weight:700;letter-spacing:.03em;
  text-align:left;cursor:pointer;transition:background .16s ease,color .16s ease;
}
.fold__trigger:hover{background:rgba(38,227,216,.08)}
.fold__icon{position:relative;flex:0 0 auto;width:12px;height:12px;transition:transform .22s ease}
.fold__icon::before,.fold__icon::after{content:"";position:absolute;background:var(--cyan);top:50%;left:0;right:0;height:2px;margin-top:-1px;transition:background .2s ease}
.fold__icon::after{transform:rotate(90deg)}
.fold__trigger[aria-expanded="true"] .fold__icon{transform:rotate(45deg)}
.fold__trigger[aria-expanded="true"] .fold__icon::before,.fold__trigger[aria-expanded="true"] .fold__icon::after{background:var(--signal)}
.fold__panel{padding:0 18px 18px;color:var(--muted);font-size:14.5px}
.fold__panel[hidden]{display:none}
.fold__panel p:last-child{margin-bottom:0}

/* media frames */
.media-frame{
  position:relative;display:block;overflow:hidden;
  border:1px solid var(--line);background:linear-gradient(150deg,#0A1B36 0%,#16355F 100%);
  clip-path:var(--cut-corner);aspect-ratio:16/10;margin:0;
}
.media-frame img{display:block;width:100%;height:100%;object-fit:cover}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame--tall{aspect-ratio:3/4}
.media-frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(115deg,transparent 52%,rgba(38,227,216,.16) 57%,transparent 63%);
}
.media-frame__placeholder{
  position:absolute;inset:0;display:grid;place-items:center;padding:16px;
  font-family:var(--mono);font-size:11.5px;letter-spacing:.16em;color:rgba(143,246,239,.65);
  text-align:center;background-image:
    linear-gradient(rgba(38,227,216,.07) 1px,transparent 1px),
    linear-gradient(90deg,rgba(38,227,216,.07) 1px,transparent 1px);
  background-size:26px 26px;
}

/* reveal */
.js-ready [data-reveal]{opacity:0;transform:translateY(10px);transition:opacity .5s ease,transform .5s ease}
.js-ready [data-reveal].is-in{opacity:1;transform:none}

/* body lock for mobile nav */
@media (max-width:1023px){
  body.nav-open{overflow:hidden}
}

/* ---------- responsive header ---------- */
@media (max-width:1023px){
  .header-meta{display:none}
  .nav-toggle{display:inline-flex}
  .site-nav{
    position:fixed;inset:0;z-index:1;
    margin:0;padding:calc(84px + env(safe-area-inset-top,0px)) var(--pad) 40px;
    display:flex;flex-direction:column;align-items:stretch;gap:6px;
    overflow-y:auto;
    background:
      radial-gradient(120% 70% at 100% 0%,rgba(22,53,95,.85),transparent 62%),
      linear-gradient(180deg,rgba(5,15,34,.99),rgba(10,27,54,.99));
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .2s ease,transform .2s ease,visibility .2s ease;
  }
  .site-header[data-open] .site-nav{opacity:1;visibility:visible;transform:none}
  .site-nav__list{flex-direction:column;align-items:stretch;gap:0}
  .site-nav__link{
    display:block;padding:16px 4px;font-size:19px;font-weight:700;letter-spacing:.06em;
    border-bottom:1px solid var(--line);background:none;
  }
  .site-nav__link[aria-current="page"]{padding-left:14px;background:linear-gradient(90deg,rgba(38,227,216,.14),transparent)}
  .site-nav__link[aria-current="page"]::after{left:4px;right:auto;width:4px;top:18px;bottom:18px;height:auto}
  .site-nav__cta{margin:24px 0 0;padding:14px 18px;font-size:15px}
  .index-strip{flex-wrap:wrap;gap:12px;font-size:10.5px}
  .index-strip__code{display:none}
}
@media (max-width:860px){
  .footer-top{grid-template-columns:1fr}
}
@media (max-width:640px){
  .footer-cols{grid-template-columns:1fr 1fr}
  .footer-col--contact{grid-column:1/-1}
  .footer-base{flex-direction:column;align-items:flex-start}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}
  .js-ready [data-reveal]{opacity:1!important;transform:none!important}
  .progress-rail__fill{transition:none}
}