/* ================= reset ================= */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0}
h1,h2,h3,h4,h5,h6,p,figure,blockquote{margin:0}
img,svg{max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
ul,ol{margin:0;padding:0;list-style:none}
a{color:var(--blue-300);text-decoration:none}

/* ================= tokens ================= */
:root{
  --ink-950:#070B12;
  --ink-900:#0D1420;
  --ink-700:#1C2836;
  --cyan-500:#17C4D6;
  --blue-600:#1F6FEB;
  --blue-300:#7FB4FF;
  --amber-500:#FF8A3D;
  --amber-700:#B4531F;
  --paper-050:#F4F7FA;
  --mint-400:#4FE0B0;
  --slate-400:#8A98A8;
  --body-text:#CBD6E2;
  --font-display:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
  --shell-max:1240px;
  --shadow-stack:10px 10px 0 -1px var(--ink-700);
  --shadow-stack-paper:10px 10px 0 -1px var(--ink-900);
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ================= base type ================= */
body{
  background-color:var(--ink-950);
  color:var(--body-text);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
}
h1,h2,h3,h4,h5,h6{
  font-family:var(--font-display);
  font-weight:800;
  letter-spacing:-.02em;
  line-height:1.25;
  color:var(--paper-050);
}
h1{font-size:clamp(30px,4.4vw,44px)}
h2{font-size:clamp(24px,3.2vw,32px)}
h3{font-size:24px}
h4{font-size:20px}
h5,h6{font-size:17px}
.mono{font-family:var(--font-mono);font-size:.92em;letter-spacing:.04em}
.lede{font-size:19px;line-height:1.8;color:#D5DFE9;max-width:40ch}
.hint{font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--slate-400)}
.bullets{list-style:disc;padding-left:1.25em;display:grid;gap:8px;max-width:44ch}
.bullets li::marker{color:var(--cyan-500)}

:focus-visible{outline:2px solid var(--cyan-500);outline-offset:3px}

/* ================= layout ================= */
.shell{width:100%;max-width:var(--shell-max);margin-inline:auto;padding-inline:24px}
.section{padding-block:72px}
.section--tight{padding-block:44px}
.grid{display:grid;gap:22px}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--split{grid-template-columns:minmax(200px,.36fr) minmax(0,1fr)}

/* ================= buttons & credentials ================= */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:9px 16px;border:1px solid transparent;border-radius:2px;
  background-color:var(--blue-600);color:#fff;
  font-size:15px;font-family:var(--font-body);cursor:pointer;text-decoration:none;
  transition:background-color 180ms ease,border-color 180ms ease,color 180ms ease;
}
.btn:hover{background-color:#2C7BF2;color:#fff}
.btn--ghost{background-color:transparent;border-color:var(--ink-700);color:var(--paper-050)}
.btn--ghost:hover{background-color:transparent;border-color:var(--cyan-500);color:var(--paper-050)}

.copy-btn{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:var(--slate-400);background-color:transparent;
  border:1px solid var(--ink-700);border-radius:2px;
  padding:3px 8px;cursor:pointer;
  transition:color 180ms ease,border-color 180ms ease;
}
.copy-btn:hover{color:var(--paper-050);border-color:var(--cyan-500)}
.copy-btn.is-copied{color:var(--amber-500);border-color:var(--amber-500)}
.copy-btn--tiny{font-size:10px;padding:2px 7px}

.version-badge{
  display:inline-flex;align-items:center;gap:8px;
  padding:6px 8px 6px 12px;
  border:1px solid var(--ink-700);border-radius:2px;
  background-color:var(--ink-900);
}
.version-badge__label{font-size:12px;color:var(--slate-400);white-space:nowrap}
.version-badge__num{font-size:13px;color:var(--mint-400);letter-spacing:.08em}

/* ================= header ================= */
.site-header{position:relative;z-index:40;background-color:var(--ink-950)}

.scroll-rail{position:fixed;top:0;left:0;right:0;height:2px;background-color:var(--ink-700);z-index:90}
.scroll-rail__fill{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:left center;
  background-image:linear-gradient(90deg,var(--blue-600),var(--cyan-500));
}

.top-strip{background-color:var(--ink-900);border-bottom:1px solid var(--ink-700)}
.top-strip__inner{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding-block:9px;
}
.top-strip__note{
  display:inline-flex;align-items:center;gap:10px;
  font-size:12px;letter-spacing:.14em;color:var(--paper-050);
}
.top-strip__note::before{content:"";width:6px;height:6px;background-color:var(--cyan-500)}
.top-strip__meta{font-size:11px;letter-spacing:.2em;color:var(--slate-400);white-space:nowrap}

.masthead{
  background-color:var(--ink-950);
  background-image:
    repeating-linear-gradient(90deg,rgba(28,40,54,.55) 0 1px,transparent 1px 96px),
    repeating-linear-gradient(0deg,rgba(28,40,54,.35) 0 1px,transparent 1px 96px);
  border-bottom:1px solid var(--ink-700);
}
.masthead__inner{
  display:grid;grid-template-columns:1fr auto 1fr auto;
  align-items:center;gap:24px;
  padding-block:22px 20px;
}
.masthead__meta{font-size:11px;letter-spacing:.18em;color:var(--slate-400);white-space:nowrap}
.masthead__tools{display:flex;align-items:center;justify-content:flex-end;gap:10px;flex-wrap:wrap}

.brand{display:inline-flex;align-items:center;gap:12px;text-decoration:none;color:var(--paper-050)}
.brand__mark{
  position:relative;flex:0 0 auto;
  width:34px;height:34px;
  border:1px solid var(--ink-700);
  background-color:var(--ink-900);
}
.brand__mark::before{
  content:"";position:absolute;left:8px;top:8px;
  width:16px;height:16px;border:1px solid var(--cyan-500);
}
.brand__mark::after{
  content:"";position:absolute;left:14px;top:14px;
  width:4px;height:4px;background-color:var(--cyan-500);
}
.brand__text{display:grid;gap:2px}
.brand__name{
  font-family:var(--font-display);font-weight:800;
  font-size:22px;letter-spacing:-.02em;line-height:1.1;color:var(--paper-050);
}
.brand__sub{font-size:11px;letter-spacing:.22em;color:var(--slate-400)}

.nav-toggle{
  display:none;align-items:center;gap:9px;
  background-color:transparent;border:1px solid var(--ink-700);border-radius:2px;
  padding:8px 12px;color:var(--paper-050);font-size:14px;cursor:pointer;
  transition:border-color 180ms ease;
}
.nav-toggle:hover{border-color:var(--cyan-500)}
.nav-toggle__icon{position:relative;display:block;width:16px;height:2px;background-color:var(--cyan-500)}
.nav-toggle__icon::before,
.nav-toggle__icon::after{content:"";position:absolute;left:0;width:16px;height:2px;background-color:var(--cyan-500)}
.nav-toggle__icon::before{top:-5px}
.nav-toggle__icon::after{top:5px}

.main-nav{position:relative;background-color:var(--ink-950);border-bottom:1px solid var(--ink-700)}
.main-nav::before{
  content:"";position:absolute;top:-1px;left:0;
  width:min(26vw,200px);height:1px;background-color:var(--cyan-500);
}
.main-nav__inner{display:flex;justify-content:center}
.nav-list{display:flex;flex-wrap:wrap;justify-content:center;gap:2px}
.nav-list a{
  display:inline-flex;align-items:baseline;gap:8px;
  padding:14px 16px 13px;
  border-bottom:2px solid transparent;
  color:var(--paper-050);font-size:15px;
  transition:color 180ms ease,border-color 180ms ease;
}
.nav-list a:hover{border-bottom-color:var(--ink-700);color:var(--blue-300)}
.nav-list a[aria-current="page"]{border-bottom-color:var(--cyan-500);color:var(--paper-050)}
.nav-list__idx{font-size:11px;letter-spacing:.12em;color:var(--slate-400)}
.nav-list a[aria-current="page"] .nav-list__idx{color:var(--cyan-500)}

/* ================= footer ================= */
.site-footer{
  position:relative;margin-top:80px;
  background-color:var(--ink-950);
  border-top:1px solid var(--ink-700);
}
.site-footer::before{
  content:"";position:absolute;top:-1px;left:0;
  width:min(40vw,320px);height:1px;background-color:var(--cyan-500);
}
.footer-grid{
  display:grid;
  grid-template-columns:1.25fr .85fr .85fr 1.5fr;
  gap:32px;
  padding-block:56px 40px;
  border-bottom:1px solid var(--ink-700);
}
.footer-brand__name{
  font-family:var(--font-display);font-weight:800;font-size:20px;
  letter-spacing:-.02em;color:var(--paper-050);
}
.footer-brand__meta{font-size:11px;letter-spacing:.18em;color:var(--cyan-500);margin-top:8px}
.footer-brand__line{margin-top:12px;font-size:14px;line-height:1.7;color:var(--body-text);max-width:26ch}
.footer-stamp-list{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}

.stamp{
  display:inline-block;
  border:1px solid var(--ink-700);border-radius:2px;
  padding:2px 8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  color:var(--slate-400);
}
.stamp--cyan{border-color:var(--cyan-500);color:var(--cyan-500)}
.stamp--amber{border-color:var(--amber-500);color:var(--amber-500)}
.stamp--mint{border-color:var(--mint-400);color:var(--mint-400)}

.footer-col__title{font-size:11px;letter-spacing:.2em;color:var(--slate-400);margin-bottom:14px}
.footer-col__list{display:grid;gap:10px}
.footer-col__list a{font-size:15px;color:var(--paper-050);border-bottom:1px solid transparent;transition:color 180ms ease,border-color 180ms ease}
.footer-col__list a:hover{color:var(--blue-300);border-bottom-color:var(--ink-700)}
.footer-col__line{margin-bottom:9px;font-size:14px;line-height:1.7;color:var(--body-text)}
.footer-col__line .mono{color:var(--paper-050)}
.footer-col__note{font-size:13px;line-height:1.7;color:var(--slate-400)}

.footer-bottom{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px;
  padding-block:22px 40px;
}
.footer-note{font-size:13px;line-height:1.7;color:var(--slate-400);max-width:58ch}
.footer-legal{display:flex;flex-wrap:wrap;align-items:center;gap:10px}
.footer-legal__text{font-size:12px;letter-spacing:.08em;color:var(--slate-400)}
.footer-legal__sep{color:var(--ink-700)}

/* ================= shared components ================= */
.skip-link{
  position:absolute;left:16px;top:-64px;z-index:120;
  padding:10px 16px;border-radius:2px;
  background-color:var(--paper-050);color:var(--ink-950);
  font-family:var(--font-mono);font-size:13px;text-decoration:none;
  transition:top 160ms var(--ease);
}
.skip-link:focus{top:12px}

.breadcrumbs{margin-bottom:24px}
.breadcrumbs__list{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--slate-400);
}
.breadcrumbs__list li{display:inline-flex;align-items:center;gap:8px}
.breadcrumbs__list li+li::before{content:"/";color:var(--ink-700)}
.breadcrumbs__list a{color:var(--slate-400)}
.breadcrumbs__list a:hover{color:var(--cyan-500)}
.breadcrumbs__list [aria-current="page"]{color:var(--paper-050)}

.panel{
  position:relative;
  border:1px solid var(--ink-700);border-radius:3px;
  background-color:var(--ink-900);
  padding:28px;
  box-shadow:var(--shadow-stack);
}
.panel--paper{background-color:var(--paper-050);border-color:#D6DEE8;color:var(--ink-900);box-shadow:var(--shadow-stack-paper)}
.panel--paper h1,.panel--paper h2,.panel--paper h3,.panel--paper h4{color:var(--ink-950)}
.panel--paper a{color:var(--ink-950);text-decoration:underline;text-decoration-color:var(--blue-600);text-underline-offset:3px}
.panel--paper a:hover{text-decoration-color:var(--amber-700)}
.panel--paper .lede,.panel--paper p{color:#26313D}
.panel__label{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;
  color:var(--blue-300);margin-bottom:14px;
}
.panel__label::before{content:"";width:10px;height:2px;background-color:var(--cyan-500)}
.panel--paper .panel__label{color:var(--amber-700)}

.section-head{display:grid;gap:10px;margin-bottom:30px}
.section-head__kicker{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.2em;
  color:var(--blue-300);text-transform:uppercase;
}
.section-head__kicker::before{content:"";width:18px;height:2px;background-color:var(--cyan-500)}
.section-head__title{font-size:clamp(24px,3.2vw,44px)}

.callout{
  display:grid;gap:6px;
  padding:16px 20px;border-radius:2px;
  border:1px solid var(--ink-700);border-left:3px solid var(--amber-500);
  background-color:rgba(255,138,61,.07);
}
.callout__label{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;color:var(--amber-500)}
.callout p{font-size:15px;line-height:1.75;color:#D7E0EA;margin:0}
.callout--calm{border-left-color:var(--mint-400);background-color:rgba(79,224,176,.07)}
.callout--calm .callout__label{color:var(--mint-400)}

.filter-bar{
  display:flex;flex-wrap:wrap;gap:8px;
  padding-block:14px;
  border-top:1px solid var(--ink-700);border-bottom:1px solid var(--ink-700);
}
.filter-bar__btn{
  padding:7px 14px;border:1px solid var(--ink-700);border-radius:2px;
  background-color:transparent;color:var(--slate-400);
  font-size:14px;cursor:pointer;
  transition:color 180ms ease,border-color 180ms ease,background-color 180ms ease;
}
.filter-bar__btn:hover{color:var(--paper-050);border-color:var(--cyan-500)}
.filter-bar__btn[aria-pressed="true"]{background-color:var(--cyan-500);border-color:var(--cyan-500);color:var(--ink-950)}
[data-filter-group].is-switching [data-filter-item]{opacity:0}
[data-filter-item]{transition:opacity 180ms ease}

.img-frame{
  position:relative;display:block;overflow:hidden;
  aspect-ratio:16/9;
  border:1px solid var(--ink-700);border-radius:2px;
  background-color:var(--ink-900);
  background-image:
    repeating-linear-gradient(90deg,rgba(23,196,214,.07) 0 1px,transparent 1px 48px),
    repeating-linear-gradient(0deg,rgba(23,196,214,.07) 0 1px,transparent 1px 48px);
  box-shadow:var(--shadow-stack);
}
.img-frame img,.img-frame svg{display:block;width:100%;height:100%;object-fit:cover}
.img-frame--wide{aspect-ratio:21/9}
.img-frame--tall{aspect-ratio:4/5}
.img-frame--square{aspect-ratio:1/1}
.img-frame__cap{
  position:absolute;left:0;right:0;bottom:0;
  padding:10px 14px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  color:var(--paper-050);
  background-image:linear-gradient(0deg,rgba(7,11,18,.9),rgba(7,11,18,0));
}

[data-reveal]{
  opacity:0;transform:translateY(8px);
  transition:opacity 240ms var(--ease),transform 240ms var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}

[data-block-step]{transition:color 180ms ease,border-color 180ms ease}
[data-block-step].is-current{color:var(--cyan-500)}
[data-block-step].is-current::before{background-color:var(--cyan-500)}

/* ================= responsive ================= */
@media (max-width:1080px){
  .footer-grid{grid-template-columns:1fr 1fr;gap:34px}
  .footer-col--contact{grid-column:1 / -1}
}
@media (max-width:980px){
  .section{padding-block:56px}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .masthead__meta{display:none}
}
@media (max-width:860px){
  .shell{padding-inline:18px}
  .top-strip__meta{display:none}
  .masthead__inner{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;padding-block:16px}
  .brand{order:1}
  .nav-toggle{order:2;display:inline-flex}
  .masthead__tools{order:3;width:100%;justify-content:flex-start}
  .main-nav{display:none}
  .main-nav[data-open="true"]{display:block}
  .main-nav__inner{justify-content:flex-start;overflow-x:auto}
  .nav-list{flex-wrap:nowrap;justify-content:flex-start;gap:0}
  .nav-list a{white-space:nowrap;padding:12px 14px}
  .nav-list a:first-child .nav-list__idx{margin-left:0}
  .grid--split{grid-template-columns:minmax(0,1fr)}
  .panel{padding:22px;box-shadow:6px 6px 0 -1px var(--ink-700)}
  .panel--paper{box-shadow:6px 6px 0 -1px var(--ink-900)}
  .img-frame{box-shadow:6px 6px 0 -1px var(--ink-700)}
}
@media (max-width:720px){
  body{font-size:16px}
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:minmax(0,1fr);padding-block:44px 32px}
  .footer-bottom{flex-direction:column;align-items:flex-start}
  .lede{font-size:17px}
}
@media (max-width:520px){
  .version-badge__label{display:none}
  .masthead__docs{display:none}
  .panel{padding:18px}
}

/* ================= reduced motion ================= */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  [data-reveal]{opacity:1;transform:none}
  .scroll-rail__fill{transition:none}
  .skip-link{transition:none}
}