:root{
  --ink-900:#0A0F1C;
  --ink-800:#111A2E;
  --ink-700:#1B2540;
  --steel:#8A97A8;
  --mist:#E9EEF5;
  --paper:#F7F9FC;
  --line:#C4CDD9;
  --cyan:#19E3D0;
  --orange:#FF8A3D;
  --violet:#5B6CFF;
  --text:#1B2433;

  --line-dark:rgba(138,151,168,.26);
  --line-light:#D8E0EA;
  --cyan-soft:rgba(25,227,208,.14);

  --font-head:"HarmonyOS Sans SC","Source Han Sans SC","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;

  --max:1240px;
  --gutter:24px;
  --radius:2px;
  --shadow-float:0 20px 44px -22px rgba(10,15,28,.82);
  --ease:cubic-bezier(.22,.61,.36,1);
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
html:focus-within{scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote{margin:0}
ul[class],ol[class]{list-style:none;padding:0}
img,svg{display:block;max-width:100%;height:auto}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
::selection{background:var(--cyan);color:#04222A}
:focus-visible{outline:2px solid var(--violet);outline-offset:3px;border-radius:1px}
.site-header :focus-visible,
.site-footer :focus-visible,
.quick-rail :focus-visible{outline-color:var(--cyan)}

body{
  min-height:100vh;
  background:var(--paper);
  color:var(--text);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3,h4,h5{
  font-family:var(--font-head);
  font-weight:600;
  letter-spacing:-.02em;
  line-height:1.25;
  color:inherit;
}
h1{font-size:clamp(32px,4vw,44px);line-height:1.15}
h2{font-size:clamp(24px,3vw,30px);line-height:1.25}
h3{font-size:20px;line-height:1.4}

.skip-link{
  position:fixed;
  left:16px;
  top:-90px;
  z-index:200;
  padding:10px 18px;
  background:var(--cyan);
  color:#04222A;
  font-family:var(--font-head);
  font-size:14px;
  font-weight:600;
  letter-spacing:.02em;
  border-radius:var(--radius);
  transition:top .15s var(--ease);
}
.skip-link:focus{top:14px}

/* ---------- layout utilities ---------- */
.container{
  width:100%;
  max-width:var(--max);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.section{padding-block:clamp(48px,7vw,88px)}
.section--tight{padding-block:clamp(32px,4vw,56px)}
.section-head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  justify-content:space-between;
  gap:12px 24px;
  margin-bottom:32px;
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:13px;
  line-height:1.4;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--steel);
}
.eyebrow::before{content:"";width:18px;height:1px;background:currentColor;opacity:.75}
.index-tag{
  font-family:var(--font-mono);
  font-size:13px;
  line-height:1.4;
  letter-spacing:.08em;
  color:var(--steel);
  font-variant-numeric:tabular-nums;
}
.display-title{
  font-family:var(--font-head);
  font-size:clamp(32px,4.6vw,44px);
  line-height:1.12;
  letter-spacing:-.025em;
  font-weight:600;
}
.lede{
  font-size:clamp(16px,1.6vw,18px);
  line-height:1.75;
  color:#3C4759;
  max-width:62ch;
}
.prose{font-size:16px;line-height:1.8;color:#2A3446}
.prose p+p{margin-top:1em}
.prose h2{margin-top:1.6em;margin-bottom:.55em}
.prose h3{margin-top:1.35em;margin-bottom:.5em}
.prose ul,.prose ol{padding-left:1.25em;margin-block:1em}
.prose ul{list-style:disc}
.prose ol{list-style:decimal}
.prose li+li{margin-top:.45em}
.prose a{color:var(--violet);text-decoration:underline;text-underline-offset:3px}
.prose strong{font-weight:600;color:var(--ink-900)}
.prose hr{border:0;border-top:1px solid var(--line);margin-block:2em}

.grid-12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:24px;
}
.col-4{grid-column:span 4}
.col-6{grid-column:span 6}
.col-8{grid-column:span 8}
.col-12{grid-column:span 12}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 20px;
  border:1px solid transparent;
  border-radius:var(--radius);
  font-family:var(--font-head);
  font-size:15px;
  font-weight:600;
  line-height:1.2;
  letter-spacing:.01em;
  white-space:nowrap;
  transition:background .12s var(--ease),color .12s var(--ease),border-color .12s var(--ease),transform .12s var(--ease);
}
.btn-primary{background:var(--cyan);color:#04222A;border-color:var(--cyan)}
.btn-primary:hover{background:#0FD3C1;border-color:#0FD3C1;transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--ink-900);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--ink-900);background:rgba(10,15,28,.04)}
.btn-dark{background:var(--ink-900);color:var(--mist);border-color:var(--ink-900)}
.btn-dark:hover{background:var(--ink-700);border-color:var(--ink-700);transform:translateY(-1px)}
.btn-sm{padding:8px 14px;font-size:13px}

/* ---------- breadcrumb ---------- */
.breadcrumb{padding-block:14px}
.breadcrumb-list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.04em;
  color:var(--steel);
}
.breadcrumb-item{display:inline-flex;align-items:center;gap:8px}
.breadcrumb-item:not(:last-child)::after{content:"/";color:var(--line)}
.breadcrumb-link{color:#5A677A;transition:color .12s var(--ease)}
.breadcrumb-link:hover{color:var(--ink-900);text-decoration:underline;text-underline-offset:3px}
.breadcrumb-current{color:var(--ink-900)}

/* ---------- figure / image frames ---------- */
.figure-frame{
  position:relative;
  display:block;
  overflow:hidden;
  border:1px solid var(--line);
  border-radius:var(--radius);
  background:linear-gradient(160deg,#DDE5EF,#EEF3F9);
}
.figure-frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:
    linear-gradient(rgba(138,151,168,.16) 1px,transparent 1px),
    linear-gradient(90deg,rgba(138,151,168,.16) 1px,transparent 1px);
  background-size:48px 48px;
  opacity:.7;
}
.figure-img{display:block;width:100%;height:100%;object-fit:cover;position:relative;z-index:1}
.figure-frame--16-10{aspect-ratio:16/10}
.figure-frame--4-3{aspect-ratio:4/3}
.figure-frame--1-1{aspect-ratio:1/1}
.figure-frame--dark{
  border-color:rgba(138,151,168,.28);
  background:linear-gradient(160deg,var(--ink-800),var(--ink-700));
}
.figure-frame--dark::after{opacity:.45;background-size:32px 32px}
.figure-caption{
  margin-top:8px;
  font-family:var(--font-mono);
  font-size:12px;
  line-height:1.5;
  letter-spacing:.04em;
  color:var(--steel);
}

/* ---------- tabs ---------- */
.tabs{display:block}
.tab-list{
  display:inline-flex;
  flex-wrap:wrap;
  gap:4px;
  padding:4px;
  border:1px solid var(--line);
  border-radius:999px;
  background:#FFFFFF;
}
.tab{
  padding:8px 16px;
  border-radius:999px;
  font-family:var(--font-head);
  font-size:13px;
  font-weight:500;
  letter-spacing:.02em;
  color:#5A677A;
  transition:background .18s var(--ease),color .18s var(--ease);
}
.tab:hover{color:var(--ink-900)}
.tab[aria-selected="true"]{background:var(--ink-900);color:var(--cyan)}
.tab-panel{padding-top:22px}
.tab-panel[hidden]{display:none}
.tab-list--dark{background:rgba(17,26,46,.9);border-color:rgba(138,151,168,.28)}
.tab-list--dark .tab{color:#9FACBE}
.tab-list--dark .tab:hover{color:var(--mist)}
.tab-list--dark .tab[aria-selected="true"]{background:var(--cyan);color:#04222A}

/* ---------- header ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:90;
  padding:14px var(--gutter) 0;
  background:transparent;
}
.header-shell{max-width:1320px;margin-inline:auto}
.nav-island{
  display:flex;
  align-items:center;
  gap:16px;
  padding:10px 12px 10px 18px;
  border:1px solid rgba(138,151,168,.24);
  border-radius:999px;
  background:rgba(10,15,28,.94);
  color:var(--mist);
  box-shadow:var(--shadow-float);
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  backdrop-filter:blur(14px) saturate(140%);
}
.brand{display:flex;align-items:center;gap:10px;flex:0 0 auto;color:var(--mist)}
.brand-mark{
  position:relative;
  width:22px;
  height:22px;
  flex:0 0 auto;
  border:1px solid var(--cyan);
  background:linear-gradient(135deg,rgba(25,227,208,.30),transparent 72%);
}
.brand-mark::after{
  content:"";
  position:absolute;
  inset:3px;
  background:var(--cyan);
  clip-path:polygon(50% 0,62% 38%,100% 50%,62% 62%,50% 100%,38% 62%,0 50%,38% 38%);
}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-name{
  font-family:var(--font-head);
  font-size:16px;
  font-weight:600;
  letter-spacing:.02em;
  color:var(--mist);
}
.brand-tag{
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.05em;
  color:var(--steel);
  white-space:nowrap;
}
.primary-nav{margin-inline:auto}
.nav-list{display:flex;align-items:center;gap:2px;flex-wrap:nowrap}
.nav-link{
  position:relative;
  display:inline-block;
  padding:8px 11px;
  border-radius:999px;
  font-family:var(--font-head);
  font-size:13px;
  font-weight:500;
  letter-spacing:.02em;
  color:#B9C4D4;
  white-space:nowrap;
  transition:color .12s var(--ease),background .12s var(--ease);
}
.nav-link:hover{color:var(--mist);background:rgba(138,151,168,.14)}
.nav-link[aria-current="page"]{color:var(--cyan);background:rgba(25,227,208,.10)}
.nav-link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:11px;
  right:11px;
  bottom:4px;
  height:1px;
  background:var(--cyan);
}
.header-actions{display:flex;align-items:center;gap:8px;flex:0 0 auto}
.version-chip{
  display:inline-flex;
  align-items:center;
  gap:7px;
  padding:6px 12px;
  border:1px solid rgba(138,151,168,.32);
  border-radius:999px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.04em;
  color:#C6D0DE;
  transition:border-color .12s var(--ease),color .12s var(--ease);
}
.version-chip:hover{border-color:var(--cyan);color:var(--cyan)}
.status-dot{
  width:6px;
  height:6px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--cyan);
  box-shadow:0 0 0 3px rgba(25,227,208,.16);
  animation:pulse 2.8s ease-in-out infinite;
}
@keyframes pulse{
  0%,100%{opacity:1;transform:scale(1)}
  50%{opacity:.55;transform:scale(.82)}
}
.nav-toggle{
  display:none;
  width:40px;
  height:40px;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:4px;
  border:1px solid rgba(138,151,168,.32);
  border-radius:999px;
  color:var(--mist);
  transition:border-color .12s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan)}
.nav-toggle-bar{
  display:block;
  width:16px;
  height:1.5px;
  background:currentColor;
  transition:transform .18s var(--ease),opacity .18s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1){transform:translateY(5.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3){transform:translateY(-5.5px) rotate(-45deg)}

/* ---------- quick rail ---------- */
.quick-rail{
  position:fixed;
  right:16px;
  top:50%;
  transform:translateY(-50%);
  z-index:70;
  display:none;
}
.quick-rail-list{display:flex;flex-direction:column;gap:8px}
.quick-rail-link{
  display:block;
  padding:14px 8px;
  writing-mode:vertical-rl;
  text-orientation:mixed;
  letter-spacing:.16em;
  font-family:var(--font-head);
  font-size:12px;
  color:#4A5768;
  background:rgba(247,249,252,.94);
  border:1px solid var(--line);
  border-radius:var(--radius);
  transition:color .12s var(--ease),background .12s var(--ease),border-color .12s var(--ease);
}
.quick-rail-link:hover{color:var(--ink-900);border-color:var(--ink-900);background:#FFFFFF}
.quick-rail-text{display:block}

/* ---------- footer ---------- */
.site-footer{
  background-color:var(--ink-900);
  background-image:
    radial-gradient(120% 80% at 82% 0%,rgba(91,108,255,.22),transparent 62%),
    linear-gradient(rgba(138,151,168,.07) 1px,transparent 1px),
    linear-gradient(90deg,rgba(138,151,168,.07) 1px,transparent 1px);
  background-size:100% 100%,72px 72px,72px 72px;
  border-top:1px solid rgba(25,227,208,.28);
  color:#B9C4D4;
}
.footer-inner{
  max-width:var(--max);
  margin-inline:auto;
  padding:clamp(48px,6vw,72px) var(--gutter) 28px;
}
.footer-top{
  display:grid;
  grid-template-columns:1.5fr .8fr .8fr 1.2fr;
  gap:clamp(24px,4vw,48px);
  padding-bottom:40px;
  border-bottom:1px solid var(--line-dark);
}
.footer-brand{min-width:0}
.footer-wordmark{
  font-family:var(--font-head);
  font-size:22px;
  font-weight:600;
  letter-spacing:-.01em;
  color:var(--mist);
}
.footer-lead{
  margin-top:10px;
  max-width:32ch;
  font-size:14px;
  line-height:1.75;
  color:#8E9BAD;
}
.footer-status{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}
.footer-badge{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 10px;
  border:1px solid var(--line-dark);
  border-radius:var(--radius);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:#9FACBE;
}
.footer-col{min-width:0}
.footer-col-title{
  margin-bottom:16px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--steel);
}
.footer-links{display:flex;flex-direction:column;gap:10px}
.footer-link{
  display:inline-flex;
  align-items:center;
  gap:8px;
  font-size:14px;
  color:#C2CCDA;
  transition:color .12s var(--ease);
}
.footer-link::before{
  content:"";
  width:10px;
  height:1px;
  background:currentColor;
  opacity:.45;
  transition:width .12s var(--ease),opacity .12s var(--ease);
}
.footer-link:hover{color:var(--cyan)}
.footer-link:hover::before{width:16px;opacity:1}
.footer-contact{min-width:0}
.contact-item{
  display:grid;
  grid-template-columns:46px minmax(0,1fr);
  gap:10px;
  padding:9px 0;
  border-top:1px solid rgba(138,151,168,.12);
  font-size:14px;
  line-height:1.65;
}
.contact-item:first-of-type{border-top:0;padding-top:0}
.contact-label{
  padding-top:2px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  color:var(--steel);
}
.contact-value{color:#D5DDE8;word-break:break-word;overflow-wrap:anywhere}
.footer-note{
  margin-top:14px;
  font-size:12.5px;
  line-height:1.8;
  color:#7D8A9C;
}
.footer-base{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 24px;
  padding-top:22px;
}
.footer-copy,
.footer-icp{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.04em;
  color:#7D8A9C;
  font-variant-numeric:tabular-nums;
}
.footer-legal{display:flex;flex-wrap:wrap;gap:8px 18px}
.footer-legal a{
  font-size:13px;
  color:#9FACBE;
  transition:color .12s var(--ease);
}
.footer-legal a:hover{color:var(--cyan)}

/* ---------- motion ---------- */
html.js-ready [data-reveal]{
  opacity:0;
  transform:translateY(12px);
  transition:opacity .24s var(--ease),transform .24s var(--ease);
}
html.js-ready [data-reveal].is-visible{opacity:1;transform:none}
.scroll-meter{
  position:fixed;
  top:0;
  left:0;
  width:0;
  height:2px;
  z-index:100;
  pointer-events:none;
  background:linear-gradient(90deg,var(--cyan),var(--violet));
}

/* ---------- responsive ---------- */
@media (max-width:1200px){
  .brand-tag{display:none}
}
@media (max-width:1080px){
  .version-chip{display:none}
}
@media (max-width:980px){
  .site-header{padding-top:12px}
  .nav-island{
    flex-wrap:wrap;
    gap:10px;
    padding:10px 12px;
    border-radius:20px;
  }
  .brand{flex:1 1 auto}
  .header-actions{margin-left:auto}
  .nav-toggle{display:inline-flex}
  .primary-nav{
    order:3;
    flex:1 0 100%;
    margin:0;
    display:none;
    padding-top:8px;
    border-top:1px solid rgba(138,151,168,.20);
  }
  .primary-nav[data-open]{display:block}
  .nav-list{flex-direction:column;align-items:stretch;gap:2px}
  .nav-link{display:block;padding:11px 12px;border-radius:10px;font-size:14px}
  .nav-link[aria-current="page"]::after{left:12px;right:12px;bottom:6px}
  .grid-12{grid-template-columns:repeat(6,minmax(0,1fr))}
  .col-4,.col-6{grid-column:span 3}
  .col-8,.col-12{grid-column:span 6}
  .footer-top{grid-template-columns:1fr 1fr;gap:32px}
}
@media (max-width:640px){
  :root{--gutter:18px}
  .site-header{padding-top:10px}
  .nav-island{padding:9px 10px;gap:8px}
  .header-actions .btn-sm{padding:7px 12px;font-size:12.5px}
  .grid-12{grid-template-columns:repeat(2,minmax(0,1fr))}
  .col-4,.col-6,.col-8,.col-12{grid-column:span 2}
  .footer-top{grid-template-columns:1fr}
  .footer-base{flex-direction:column;align-items:flex-start;gap:12px}
}
@media (min-width:1400px){
  .quick-rail{display:block}
}

@media (prefers-reduced-motion:reduce){
  html:focus-within{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html.js-ready [data-reveal]{opacity:1;transform:none}
  .status-dot{animation:none}
  .scroll-meter{transition:none}
}