:root{
  --ink:#06120F;
  --felt:#0E211B;
  --drawer:#16302A;
  --mist:#E8F1EC;
  --neon:#25F5CF;
  --amber:#F3B23F;
  --rose:#FF4E7A;
  --steel:#8FBBAE;
  --edge:#2C4A42;
  --glow:#FFD98A;
  --font-display:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:ui-monospace,"JetBrains Mono","SFMono-Regular",Menlo,Consolas,monospace;
  --w-max:1200px;
  --gutter:clamp(20px,4vw,48px);
  --ease-drawer:cubic-bezier(0.2,0.8,0.2,1);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,p,ul,ol,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
html,body{min-height:100%}
body{
  background-color:var(--ink);
  background-image:
    radial-gradient(circle at 84% -8%,rgba(37,245,207,.11),transparent 46%),
    radial-gradient(circle at 2% 104%,rgba(243,178,63,.08),transparent 44%),
    repeating-linear-gradient(0deg,rgba(44,74,66,.34) 0 1px,transparent 1px 96px),
    repeating-linear-gradient(90deg,rgba(44,74,66,.26) 0 1px,transparent 1px 96px);
  background-attachment:fixed;
  color:var(--mist);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.85;
  letter-spacing:.005em;
}
::selection{background:var(--neon);color:#04120e}
:focus-visible{outline:2px solid var(--amber);outline-offset:3px}
.skip-link{
  position:fixed;left:16px;top:12px;z-index:99;
  transform:translateY(-220%);
  padding:10px 16px;border:2px solid #04120e;border-radius:6px;
  background:var(--neon);color:#04120e;
  font-family:var(--font-mono);font-size:13px;letter-spacing:.08em;
  transition:transform .2s var(--ease-drawer);
}
.skip-link:focus,.skip-link:focus-visible{transform:translateY(0)}
.read-progress{position:fixed;top:0;left:0;right:0;height:3px;z-index:80;background:rgba(44,74,66,.55)}
.read-progress-bar{display:block;height:100%;width:0;background:var(--neon);box-shadow:0 0 12px rgba(37,245,207,.75)}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:60;padding:16px var(--gutter) 10px}
.header-island{
  position:relative;
  max-width:var(--w-max);
  margin:0 auto;
  display:flex;align-items:center;gap:clamp(8px,1.4vw,20px);
  padding:9px 10px 9px 14px;
  background:rgba(14,33,27,.96);
  border:2px solid var(--edge);
  border-radius:999px;
  box-shadow:0 16px 32px -24px rgba(0,0,0,.95),inset 0 0 0 1px rgba(6,18,15,.65);
  transition:max-width .28s var(--ease-drawer),padding .28s var(--ease-drawer),border-color .28s var(--ease-drawer),background .28s var(--ease-drawer);
}
.site-header[data-scrolled="true"] .header-island{
  max-width:1000px;
  padding:6px 8px 6px 12px;
  border-color:rgba(37,245,207,.45);
  background:rgba(6,18,15,.97);
}
.brand{display:flex;align-items:center;gap:10px;flex:0 0 auto;border-radius:999px}
.brand-mark{
  display:grid;place-items:center;width:38px;height:38px;flex:0 0 auto;
  border:2px solid #04120e;border-radius:10px;
  background:linear-gradient(160deg,var(--neon),#0e8b78);
  color:#03120f;font-family:var(--font-mono);font-weight:700;font-size:15px;letter-spacing:.02em;
  box-shadow:3px 3px 0 0 rgba(243,178,63,.85);
}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-name{font-size:15px;font-weight:900;letter-spacing:.01em;color:var(--mist)}
.brand-tagline{font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--steel)}
.site-nav{flex:1 1 auto;min-width:0;display:flex;justify-content:flex-end}
.site-nav-handle{display:none}
.site-nav-list{display:flex;align-items:center;gap:2px;flex-wrap:nowrap}
.nav-link{
  display:inline-block;padding:8px 11px;border-radius:999px;
  border:1px solid transparent;
  font-size:13.5px;font-weight:500;color:#cfe3da;white-space:nowrap;
  transition:color .18s,border-color .18s,background .18s;
}
.nav-link:hover{color:var(--neon);border-color:rgba(37,245,207,.35);background:rgba(37,245,207,.07)}
.nav-link[aria-current="page"]{
  color:var(--neon);
  border-color:rgba(37,245,207,.62);
  background:rgba(37,245,207,.1);
  box-shadow:inset 0 -2px 0 0 rgba(37,245,207,.4);
}
.header-tools{display:flex;align-items:center;gap:8px;flex:0 0 auto;margin-left:auto}
.chip{
  display:inline-flex;align-items:center;gap:6px;
  padding:5px 9px;border:1px solid var(--edge);border-radius:6px;
  background:rgba(6,18,15,.62);color:var(--steel);
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.12em;white-space:nowrap;
}
.version-chip{color:var(--amber);border-color:rgba(243,178,63,.55);text-shadow:0 0 8px rgba(243,178,63,.35);animation:chip-breathe 6s ease-in-out infinite}
.version-chip[aria-expanded="true"]{background:rgba(243,178,63,.16);border-color:var(--amber)}
.ios-chip{color:var(--neon);border-color:rgba(37,245,207,.5)}
@keyframes chip-breathe{0%,86%,100%{filter:brightness(1)}92%{filter:brightness(1.45)}}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:10px 18px;border:2px solid transparent;border-radius:999px;
  font-size:14px;font-weight:700;letter-spacing:.02em;line-height:1.2;
  transition:background .18s,border-color .18s,color .18s,box-shadow .18s,transform .16s var(--ease-drawer);
}
.btn-primary{background:var(--neon);color:#04120e;border-color:#04120e;box-shadow:0 4px 0 0 rgba(6,18,15,.9),0 0 0 1px rgba(37,245,207,.5)}
.btn-primary:hover{background:var(--glow);box-shadow:0 4px 0 0 rgba(6,18,15,.9),0 0 22px rgba(37,245,207,.5)}
.btn-ghost{background:transparent;color:var(--mist);border-color:var(--edge)}
.btn-ghost:hover{border-color:var(--neon);color:var(--neon)}
.btn-rose{background:transparent;color:#ffd0da;border-color:var(--rose);box-shadow:0 0 0 1px rgba(255,78,122,.35)}
.btn-rose:hover{background:rgba(255,78,122,.14);color:#fff;box-shadow:0 0 20px rgba(255,78,122,.35)}
.btn-row{display:flex;flex-wrap:wrap;gap:12px}
.nav-toggle{
  display:none;align-items:center;gap:8px;
  padding:8px 12px;border:2px solid rgba(37,245,207,.45);border-radius:999px;
  background:rgba(37,245,207,.08);color:var(--neon);
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.12em;
}
.nav-toggle:hover{border-color:var(--neon)}
.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:currentColor;transition:transform .2s var(--ease-drawer),top .2s var(--ease-drawer),bottom .2s var(--ease-drawer)}
.nav-toggle-bars::before{top:0}
.nav-toggle-bars::after{bottom:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{top:4px;transform:rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{bottom:4px;transform:rotate(-45deg)}
.version-note{
  position:absolute;top:calc(100% + 12px);right:12px;z-index:6;
  width:min(288px,calc(100vw - 32px));
  padding:14px 16px;border:2px solid rgba(243,178,63,.6);border-radius:12px;
  background:var(--drawer);
  box-shadow:0 22px 44px -26px #000,4px 4px 0 0 rgba(243,178,63,.22);
}
.version-note[hidden]{display:none}
.version-note-head{font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;color:var(--amber);margin-bottom:6px}
.version-note-meta{font-size:13px;line-height:1.75;color:#c6dcd3;margin-bottom:10px}
.text-link{display:inline-block;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--neon);border-bottom:1px solid rgba(37,245,207,.5);padding-bottom:2px}
.text-link:hover{color:var(--glow);border-color:var(--glow)}
.nav-scrim{position:fixed;inset:0;z-index:55;background:rgba(4,12,10,.74)}
.nav-scrim[hidden]{display:none}

/* ---------- footer ---------- */
.site-footer{margin-top:clamp(72px,10vw,140px);background:var(--felt);border-top:2px solid var(--edge);position:relative}
.site-footer::before{content:"";position:absolute;top:-2px;left:0;width:min(180px,32vw);height:2px;background:var(--neon)}
.footer-inner{padding-top:clamp(36px,5vw,56px);padding-bottom:28px}
.footer-handle{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding-bottom:14px;margin-bottom:clamp(24px,3.5vw,36px);
  border-bottom:1px dashed rgba(44,74,66,.9);
}
.footer-top{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:14px 32px;margin-bottom:clamp(28px,4vw,44px)}
.footer-brand{display:inline-flex;align-items:center;gap:10px}
.footer-mark{
  display:grid;place-items:center;width:34px;height:34px;flex:0 0 auto;
  border:2px solid #04120e;border-radius:8px;background:var(--neon);color:#04120e;
  font-family:var(--font-mono);font-weight:700;font-size:13px;
  box-shadow:3px 3px 0 0 rgba(243,178,63,.7);
}
.footer-name{font-size:16px;font-weight:900;letter-spacing:.02em}
.footer-lead{max-width:32ch;font-size:14.5px;line-height:1.8;color:var(--steel)}
.footer-grid{
  display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:clamp(20px,3vw,36px);
  padding-bottom:clamp(24px,3.5vw,36px);
  border-bottom:1px solid rgba(44,74,66,.8);
}
.footer-col{min-width:0}
.footer-col-title{margin-bottom:12px;font-family:var(--font-mono);font-size:11.5px;font-weight:500;letter-spacing:.16em;color:var(--amber)}
.footer-links li+li{margin-top:7px}
.footer-link{display:inline-block;padding-bottom:2px;border-bottom:1px solid transparent;font-size:14px;color:#cfe3da;transition:color .18s,border-color .18s}
.footer-link:hover{color:var(--neon);border-color:rgba(37,245,207,.5)}
.footer-contact-list{display:flex;flex-direction:column;gap:7px}
.footer-contact-line{display:flex;align-items:baseline;gap:10px;font-size:13px;color:#c6dcd3}
.footer-contact-label{flex:0 0 auto;min-width:32px;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.12em;color:var(--steel)}
.footer-contact-value{word-break:break-all}
.footer-note{margin-top:10px;font-family:var(--font-mono);font-size:11px;line-height:1.85;letter-spacing:.06em;color:var(--steel)}
.footer-base{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:10px 28px;padding-top:22px;
}
.footer-legal,.footer-icp{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.08em;color:var(--steel)}
.footer-base-links{display:flex;flex-wrap:wrap;gap:16px}
.footer-base-links a{font-size:12px;color:var(--steel);border-bottom:1px solid rgba(143,187,174,.35);padding-bottom:1px}
.footer-base-links a:hover{color:var(--neon);border-color:rgba(37,245,207,.6)}

/* ---------- shared components ---------- */
.container{width:100%;max-width:var(--w-max);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-block:clamp(48px,7vw,104px)}
.section-head{max-width:62ch;margin-bottom:clamp(24px,4vw,48px)}
.section-kicker{display:block;margin-bottom:10px;font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--amber)}
.section-title{
  font-family:var(--font-display);font-size:clamp(28px,4.4vw,40px);font-weight:900;
  letter-spacing:-.02em;line-height:1.22;
  text-shadow:2px 0 0 rgba(37,245,207,.32),-2px 0 0 rgba(243,178,63,.24);
}
.section-lead{margin-top:14px;max-width:38ch;font-size:16px;line-height:1.85;color:#c6dcd3}
.grid{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(18px,3vw,40px)}
.span-4{grid-column:span 4}
.span-5{grid-column:span 5}
.span-6{grid-column:span 6}
.span-7{grid-column:span 7}
.span-8{grid-column:span 8}
.span-12{grid-column:span 12}
.drawer{
  position:relative;padding:18px 20px 20px;
  border:2px solid var(--edge);border-radius:4px;
  background:var(--drawer);
  box-shadow:6px 6px 0 0 rgba(6,18,15,.85);
  transition:border-color .2s,box-shadow .24s,transform .24s var(--ease-drawer);
}
.drawer:hover{border-color:rgba(37,245,207,.55);box-shadow:6px 6px 0 0 rgba(37,245,207,.18)}
.drawer-handle{
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding-bottom:12px;margin-bottom:14px;
  border-bottom:1px dashed rgba(44,74,66,.9);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--steel);
}
.drawer-code{color:var(--amber)}
.drawer-state{color:var(--neon)}
.drawer-title{margin-bottom:6px;font-size:20px;font-weight:800;letter-spacing:-.01em;line-height:1.35}
.drawer-text{font-size:14.5px;line-height:1.8;color:#c6dcd3}
.drawer-foot{margin-top:14px;padding-top:12px;border-top:1px solid rgba(44,74,66,.7);font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--steel)}
.belt{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:20px;
  min-height:180px;padding:clamp(24px,4vw,40px);
  background:var(--felt);border-block:2px solid var(--edge);
}
.belt-label{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;color:var(--steel)}
.belt-title{font-size:clamp(22px,3.4vw,32px);font-weight:900;letter-spacing:-.02em;line-height:1.3}
.belt-arrow{
  display:inline-flex;align-items:center;gap:8px;
  padding:8px 14px;border:2px solid rgba(37,245,207,.5);border-radius:999px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;color:var(--neon);white-space:nowrap;
}
.belt-arrow:hover{background:rgba(37,245,207,.1);border-color:var(--neon)}
.plate{display:grid;gap:10px;margin:0}
.media{
  position:relative;overflow:hidden;aspect-ratio:16/9;
  border:2px solid var(--edge);border-radius:4px;
  background:linear-gradient(152deg,var(--drawer),#0A1A16 58%,#101F2B 100%);
  box-shadow:6px 6px 0 0 rgba(6,18,15,.85);
}
.media img{width:100%;height:100%;object-fit:cover}
.media::after{content:"";position:absolute;left:0;right:0;bottom:0;height:3px;background:linear-gradient(90deg,var(--neon),rgba(37,245,207,0) 70%)}
.media--wide{aspect-ratio:21/9}
.media--portrait{aspect-ratio:3/4}
.media--square{aspect-ratio:1/1}
.media-caption{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;line-height:1.8;color:var(--steel)}
.section-index{padding-left:2px}
.index-list{display:flex;flex-direction:column;gap:2px}
.index-link{
  display:flex;align-items:center;gap:10px;
  padding:8px 10px;border-left:2px solid rgba(44,74,66,.9);
  font-size:13.5px;color:var(--steel);
  transition:color .18s,border-color .18s,background .18s;
}
.index-link:hover{color:var(--mist);border-color:rgba(37,245,207,.6)}
.index-link[aria-current="true"],.index-link.is-active{color:var(--neon);border-color:var(--neon);background:rgba(37,245,207,.08)}
.index-num{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--amber)}
.index-label{min-width:0}
.legend{display:flex;flex-wrap:wrap;gap:10px 20px;font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--steel)}
.legend-item{display:inline-flex;align-items:center;gap:8px}
.legend-swatch{width:10px;height:10px;flex:0 0 auto;border:1px solid rgba(6,18,15,.85);background:var(--neon)}
.legend-swatch--amber{background:var(--amber)}
.legend-swatch--rose{background:var(--rose)}
.legend-swatch--steel{background:var(--steel)}
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 8px;border:1px solid rgba(243,178,63,.5);border-radius:4px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--amber);
}
.tag--neon{border-color:rgba(37,245,207,.55);color:var(--neon)}
.tag--rose{border-color:rgba(255,78,122,.6);color:#ff9db3}
.breadcrumb{padding-top:clamp(20px,3vw,32px)}
.breadcrumb-list{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--steel)}
.breadcrumb-item{display:inline-flex;align-items:center;gap:8px}
.breadcrumb-item+.breadcrumb-item::before{content:"/";color:rgba(143,187,174,.5)}
.breadcrumb-link{color:var(--steel)}
.breadcrumb-link:hover{color:var(--neon)}
.breadcrumb-current{color:var(--mist)}
.prose{max-width:66ch;font-size:16.5px;line-height:1.85;color:#d3e5dd}
.prose p+p{margin-top:1.05em}
.prose h2{margin-top:1.8em;margin-bottom:.5em;font-size:24px;font-weight:900;letter-spacing:-.01em;line-height:1.35}
.prose h3{margin-top:1.5em;margin-bottom:.4em;font-size:18px;font-weight:800}
.prose ul,.prose ol{margin-top:.9em;display:grid;gap:.5em}
.prose li{padding-left:1.4em;position:relative}
.prose li::before{content:"·";position:absolute;left:.3em;color:var(--amber)}
.prose a{color:var(--neon);border-bottom:1px solid rgba(37,245,207,.45)}
.prose strong{color:var(--mist);font-weight:700}
.mono{font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;color:var(--steel)}
.note{font-family:var(--font-mono);font-size:11.5px;line-height:1.9;letter-spacing:.08em;color:var(--steel)}
.rule{height:2px;border:0;margin-block:clamp(32px,5vw,64px);background:repeating-linear-gradient(90deg,var(--edge) 0 12px,transparent 12px 22px)}

/* ---------- responsive ---------- */
@media (max-width:1180px){
  .header-cta{display:none}
}
@media (max-width:1024px){
  .nav-toggle{display:inline-flex}
  .header-island{border-radius:22px}
  .site-nav{
    position:fixed;top:0;right:0;bottom:0;left:auto;
    width:min(342px,86vw);flex:none;
    display:flex;flex-direction:column;justify-content:flex-start;
    padding:78px 20px 28px;
    background:var(--drawer);
    border-left:2px solid var(--neon);
    box-shadow:-28px 0 60px -32px #000;
    overflow-y:auto;
    z-index:70;
    visibility:hidden;
    transform:translateX(102%);
    transition:transform .24s var(--ease-drawer),visibility .24s var(--ease-drawer);
  }
  .site-nav[data-open="true"]{visibility:visible;transform:translateX(0)}
  .site-nav-handle{display:flex;position:absolute;top:20px;left:20px;right:20px;margin:0}
  .site-nav-list{flex-direction:column;align-items:stretch;gap:4px}
  .nav-link{
    display:block;padding:12px 14px;border-radius:8px;
    border-color:rgba(44,74,66,.95);font-size:15px;
    background:rgba(6,18,15,.4);
  }
  .nav-link[aria-current="page"]{background:rgba(37,245,207,.12)}
  .drawer-handle{padding-bottom:12px;margin-bottom:14px}
}
@media (max-width:900px){
  .span-4,.span-5,.span-6,.span-7,.span-8{grid-column:span 12}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-lead{max-width:44ch}
}
@media (max-width:760px){
  .brand-tagline{display:none}
  .site-header{padding:12px 12px 8px}
  .header-island{gap:8px;padding:7px 8px 7px 10px}
  .brand-name{font-size:13.5px}
  .brand-mark{width:34px;height:34px;font-size:13px}
  .chip{font-size:10.5px;padding:4px 7px}
}
@media (max-width:560px){
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:24px}
  .footer-base{flex-direction:column;align-items:flex-start}
  .ios-chip{display:none}
  .version-note{right:6px}
  .profile{}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important}
  .version-chip{animation:none}
}