:root{
  --ink-900:#0B1622;
  --ink-800:#122436;
  --ink-700:#1B3550;
  --ink-600:#2E4A63;
  --gray-400:#8C9AA8;
  --ivory:#EDE7DB;
  --copper:#C08B3E;
  --copper-light:#D8C39A;
  --cinnabar:#B8443A;

  --line:rgba(216,195,154,.18);
  --line-soft:rgba(140,154,168,.16);
  --paper:rgba(237,231,219,.04);
  --on-copper:#16120A;

  --font-head:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",Georgia,serif;
  --font-body:Inter,"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --r-xl:26px;
  --r-lg:18px;
  --r-md:12px;
  --r-sm:8px;
  --r-pill:999px;

  --dur-1:120ms;
  --dur-2:180ms;
  --dur-3:240ms;
  --ease:cubic-bezier(.22,.68,.32,1);

  --rail-w:264px;
  --masthead-h:58px;
  --gutter:clamp(16px,4vw,44px);
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{
  margin:0;
  min-height:100%;
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.85;
  font-weight:400;
  color:var(--ivory);
  background-color:var(--ink-900);
  background-image:
    radial-gradient(1200px 620px at 92% -12%, rgba(27,53,80,.62), transparent 68%),
    radial-gradient(900px 560px at -8% 108%, rgba(46,74,99,.34), transparent 66%),
    repeating-linear-gradient(180deg, rgba(237,231,219,.016) 0 2px, transparent 2px 6px);
  background-attachment:fixed,fixed,scroll;
  -webkit-font-smoothing:antialiased;
}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
ul,ol{margin:0;padding:0;list-style:none}
p{margin:0}
table{border-collapse:collapse}
::selection{background:rgba(192,139,62,.36);color:var(--ivory)}
:focus-visible{outline:2px solid var(--copper-light);outline-offset:3px;border-radius:3px}

h1,h2,h3,h4{margin:0;font-family:var(--font-head);font-weight:650;line-height:1.28;letter-spacing:-.01em;color:var(--ivory)}
h1{font-size:clamp(30px,5vw,40px)}
h2{font-size:clamp(23px,3.4vw,32px)}
h3{font-size:clamp(19px,2.4vw,24px)}
h4{font-size:18px}
code,.mono,time,.num{font-family:var(--font-mono);font-variant-numeric:tabular-nums;font-feature-settings:"tnum" 1}
.muted{color:var(--gray-400)}
.code{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--copper-light)}
.eyebrow{display:inline-block;font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--copper)}

/* ---------- layout ---------- */
.wrap{width:100%;max-width:1140px;margin-inline:auto;padding-inline:var(--gutter)}
.wrap--wide{max-width:1420px}
.wrap--narrow{max-width:760px}
.stack{display:block}
.stack > * + *{margin-top:var(--stack-gap,16px)}
.stack--lg{--stack-gap:clamp(20px,2.6vw,30px)}
.cluster{display:flex;flex-wrap:wrap;align-items:center;gap:10px}
.grid{display:grid;gap:clamp(14px,2vw,24px)}
.grid--2,.grid--3,.grid--asym{grid-template-columns:1fr}
.section{padding-block:clamp(28px,4.6vw,60px)}
.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(--line);margin-bottom:clamp(18px,3vw,30px)}
.section__title{font-size:clamp(22px,3vw,30px)}
.section__lead{margin-top:8px;max-width:64ch;font-size:15px;color:var(--gray-400)}
.section__index{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--copper)}
.rule{height:1px;border:0;margin:0;background:linear-gradient(90deg,var(--line),transparent)}

.prose{max-width:68ch;font-size:16px;color:rgba(237,231,219,.84)}
.prose p + p{margin-top:1em}
.prose ul{margin-top:1em;padding-inline-start:1.1em;list-style:none}
.prose li{position:relative;padding-inline-start:14px}
.prose li::before{content:"";position:absolute;inset-inline-start:0;top:.85em;width:6px;height:1px;background:var(--copper)}

#main-content{display:block;padding-block:clamp(16px,2.4vw,30px) clamp(48px,7vw,88px)}

/* ---------- buttons & chips ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:12px 20px;border-radius:var(--r-pill);
  border:1px solid var(--line);
  background:rgba(27,53,80,.55);
  color:var(--ivory);font-size:14px;letter-spacing:.02em;
  transition:border-color var(--dur-1) var(--ease),background-color var(--dur-2) var(--ease),color var(--dur-2) var(--ease),transform var(--dur-2) var(--ease);
}
.btn:hover{border-color:var(--copper-light);background:rgba(192,139,62,.14)}
.btn:active{transform:translateY(1px)}
.btn--primary{background:var(--copper);border-color:var(--copper);color:var(--on-copper);font-weight:600}
.btn--primary:hover{background:var(--copper-light);border-color:var(--copper-light);color:var(--on-copper)}
.btn--ghost{background:transparent}
.btn--sm{padding:8px 14px;font-size:13px}
.btn[aria-disabled="true"]{opacity:.5;pointer-events:none}

.chip{display:inline-flex;align-items:center;gap:6px;padding:4px 12px;border-radius:var(--r-pill);border:1px solid var(--line);background:rgba(11,22,34,.6);font-family:var(--font-mono);font-size:12px;letter-spacing:.05em;color:var(--gray-400)}
.chip--gold{border-color:rgba(192,139,62,.5);background:rgba(192,139,62,.1);color:var(--copper-light)}
.chip--red{border-color:rgba(184,68,58,.5);background:rgba(184,68,58,.12);color:#E0A199}
.chip--solid{border-color:var(--ink-600);background:var(--ink-700);color:var(--ivory)}

/* ---------- cards & panels ---------- */
.card{
  position:relative;padding:clamp(18px,2.4vw,28px);
  border:1px solid var(--line-soft);border-radius:var(--r-lg);
  background:linear-gradient(160deg,rgba(18,36,54,.92),rgba(11,22,34,.94));
  transition:border-color var(--dur-2) var(--ease),transform var(--dur-2) var(--ease);
}
.card:hover{border-color:rgba(216,195,154,.34)}
.card--flat{background:rgba(18,36,54,.6)}
.card--accent{border-color:rgba(192,139,62,.45)}
.card__head{display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;gap:10px}
.card__title{font-family:var(--font-head);font-size:20px;font-weight:650}
.card__meta{font-family:var(--font-mono);font-size:12px;color:var(--gray-400);letter-spacing:.05em}
.card__body{margin-top:10px;font-size:15px;color:rgba(237,231,219,.78)}

.panel{
  padding:clamp(20px,3vw,34px);
  border:1px solid var(--line-soft);border-radius:var(--r-xl);
  background:linear-gradient(180deg,rgba(18,36,54,.9),rgba(11,22,34,.86));
}

/* ---------- table ---------- */
.table-scroll{overflow-x:auto;border:1px solid var(--line-soft);border-radius:var(--r-lg);background:rgba(11,22,34,.5)}
.data-table{width:100%;min-width:520px;font-size:14px}
.data-table caption{padding:14px 16px 0;text-align:left;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--gray-400)}
.data-table th,.data-table td{padding:12px 16px;text-align:left;vertical-align:top;border-bottom:1px solid var(--line-soft)}
.data-table thead th{font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.08em;color:var(--copper-light);background:rgba(27,53,80,.4);border-bottom-color:var(--line)}
.data-table tbody tr:nth-child(even){background:rgba(46,74,99,.14)}
.data-table tbody tr:last-child th,.data-table tbody tr:last-child td{border-bottom:0}
.data-table .num{text-align:right;font-family:var(--font-mono);color:var(--gray-400)}

/* ---------- media ---------- */
.media{
  position:relative;isolation:isolate;overflow:hidden;
  aspect-ratio:16/10;border:1px solid var(--line-soft);border-radius:var(--r-lg);
  background:linear-gradient(150deg,rgba(27,53,80,.85),rgba(11,22,34,.92));
}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;opacity:.7;
  background-image:repeating-linear-gradient(115deg,rgba(237,231,219,.05) 0 1px,transparent 1px 9px);
}
.media img{width:100%;height:100%;object-fit:cover}
.media--wide{aspect-ratio:21/9}
.media--tall{aspect-ratio:4/5}
.media--square{aspect-ratio:1/1}
.media__caption{position:absolute;inset-inline:0;bottom:0;z-index:2;padding:12px 16px;font-size:13px;color:rgba(237,231,219,.84);background:linear-gradient(transparent,rgba(11,22,34,.92))}
.media__stamp{position:absolute;z-index:2;top:12px;inset-inline-start:12px;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--copper-light)}

/* ---------- breadcrumbs ---------- */
.breadcrumbs{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:var(--gray-400)}
.breadcrumbs li{display:flex;align-items:center;gap:8px}
.breadcrumbs li + li::before{content:"/";color:var(--ink-600)}
.breadcrumbs a{color:var(--gray-400);transition:color var(--dur-1) var(--ease)}
.breadcrumbs a:hover{color:var(--copper-light)}
.breadcrumbs [aria-current="page"]{color:var(--ivory)}

/* ---------- fold ---------- */
.fold{border:1px solid var(--line-soft);border-radius:var(--r-md);background:rgba(18,36,54,.6);overflow:hidden}
.fold + .fold{margin-top:10px}
.fold__trigger{display:flex;width:100%;align-items:center;justify-content:space-between;gap:12px;padding:14px 18px;text-align:left;font-family:var(--font-head);font-size:17px;font-weight:600;transition:background-color var(--dur-2) var(--ease)}
.fold__trigger:hover{background:rgba(192,139,62,.09)}
.fold__trigger::after{content:"+";font-family:var(--font-mono);font-size:16px;color:var(--copper);transition:transform var(--dur-3) var(--ease)}
.fold.is-open .fold__trigger::after{content:"–"}
.fold__panel{padding:0 18px 18px;font-size:15px;color:rgba(237,231,219,.82);animation:fold-in var(--dur-3) var(--ease) both}
@keyframes fold-in{from{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:none}}

/* ---------- filter ---------- */
.filter-bar{display:flex;flex-wrap:wrap;gap:8px;padding:10px;border:1px solid var(--line-soft);border-radius:var(--r-pill);background:rgba(11,22,34,.7)}
.filter-pill{padding:6px 14px;border-radius:var(--r-pill);border:1px solid transparent;font-family:var(--font-mono);font-size:12px;letter-spacing:.05em;color:var(--gray-400);transition:color var(--dur-1) var(--ease),border-color var(--dur-1) var(--ease),background-color var(--dur-2) var(--ease)}
.filter-pill:hover{color:var(--ivory);border-color:var(--line)}
.filter-pill[aria-pressed="true"]{border-color:rgba(192,139,62,.55);background:rgba(192,139,62,.16);color:var(--copper-light)}

/* ---------- skip link ---------- */
.skip-link{position:absolute;top:-72px;inset-inline-start:16px;z-index:120;padding:10px 18px;border-radius:var(--r-pill);background:var(--copper);color:var(--on-copper);font-size:14px;font-weight:600;transition:top var(--dur-2) var(--ease)}
.skip-link:focus,.skip-link:focus-visible{top:12px}

/* ---------- header ---------- */
.site-header{
  position:sticky;top:0;z-index:80;
  border-bottom:1px solid var(--line);
  background:linear-gradient(180deg,rgba(11,22,34,.97),rgba(11,22,34,.9));
}
.site-header[data-open]::before{content:"";position:fixed;inset:0;z-index:64;background:rgba(6,12,20,.62)}
.masthead{display:flex;align-items:center;gap:12px;min-height:var(--masthead-h);padding:10px var(--gutter)}
.brand{display:flex;align-items:center;gap:10px;min-width:0}
.brand__mark{display:grid;place-items:center;flex:0 0 auto;width:34px;height:34px;border-radius:11px;border:1px solid rgba(192,139,62,.55);background:linear-gradient(150deg,rgba(192,139,62,.24),rgba(11,22,34,.7));font-family:var(--font-head);font-size:17px;color:var(--copper-light)}
.brand__text{display:flex;flex-direction:column;min-width:0}
.brand__name{font-family:var(--font-head);font-size:16px;font-weight:650;letter-spacing:.02em;line-height:1.4}
.brand__meta{font-family:var(--font-mono);font-size:11px;letter-spacing:.03em;color:var(--gray-400);line-height:1.5}
.masthead__note{display:none;font-size:12px;line-height:1.7;color:var(--gray-400)}
.masthead__utils{display:none;align-items:center;gap:14px;margin-inline-start:auto}
.utility-nav{display:flex;gap:14px;font-size:13px}
.utility-nav a{color:var(--gray-400);border-bottom:1px solid transparent;transition:color var(--dur-1) var(--ease),border-color var(--dur-1) var(--ease)}
.utility-nav a:hover{color:var(--copper-light);border-bottom-color:rgba(192,139,62,.6)}
.utility-nav a[aria-current="page"]{color:var(--ivory);border-bottom-color:var(--cinnabar)}
.lang-chip{padding:3px 10px;border:1px solid var(--line-soft);border-radius:var(--r-pill);font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--gray-400)}

.nav-toggle{display:inline-flex;align-items:center;gap:9px;margin-inline-start:auto;padding:8px 14px;border:1px solid var(--line);border-radius:var(--r-pill);background:rgba(27,53,80,.5);font-size:13px;letter-spacing:.04em;color:var(--ivory);transition:border-color var(--dur-1) var(--ease),background-color var(--dur-2) var(--ease)}
.nav-toggle:hover{border-color:var(--copper-light);background:rgba(192,139,62,.14)}
.nav-toggle__bars{display:grid;gap:3px;width:14px}
.nav-toggle__bars i{display:block;height:1.5px;border-radius:2px;background:var(--copper-light);transition:transform var(--dur-2) var(--ease),opacity var(--dur-2) var(--ease)}
.site-header[data-open] .nav-toggle__bars i:nth-child(1){transform:translateY(4.5px) rotate(45deg)}
.site-header[data-open] .nav-toggle__bars i:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle__bars i:nth-child(3){transform:translateY(-4.5px) rotate(-45deg)}
.nav-toggle__label{white-space:nowrap}

.rail-nav{
  position:fixed;top:var(--masthead-h);inset-inline-end:0;
  display:flex;flex-direction:column;gap:16px;
  width:min(88vw,352px);height:calc(100dvh - var(--masthead-h));
  padding:22px 20px 30px;z-index:70;overflow-y:auto;
  border-inline-start:1px solid var(--line);
  background:linear-gradient(180deg,var(--ink-800),var(--ink-900));
  transform:translateX(104%);visibility:hidden;
  transition:transform var(--dur-3) var(--ease),visibility var(--dur-3) var(--ease);
}
.site-header[data-open] .rail-nav{transform:none;visibility:visible}
.rail-nav__caption{font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--copper)}
.rail-nav__list{display:flex;flex-direction:column;gap:2px}
.rail-link{position:relative;display:flex;align-items:baseline;gap:12px;padding:11px 14px;border:1px solid transparent;border-radius:var(--r-md);color:rgba(237,231,219,.86);transition:background-color var(--dur-2) var(--ease),border-color var(--dur-2) var(--ease),color var(--dur-2) var(--ease)}
.rail-link::before{content:"";position:absolute;inset-inline-start:0;top:14px;bottom:14px;width:2px;border-radius:2px;background:transparent;transition:background-color var(--dur-2) var(--ease)}
.rail-link:hover{background:rgba(192,139,62,.09);border-color:rgba(216,195,154,.24)}
.rail-link:hover::before{background:var(--copper)}
.rail-link__code{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--gray-400)}
.rail-link__label{font-family:var(--font-head);font-size:15px;font-weight:600;letter-spacing:.01em}
.rail-link[aria-current="page"]{background:rgba(192,139,62,.14);border-color:rgba(192,139,62,.5);color:var(--ivory)}
.rail-link[aria-current="page"]::before{background:var(--copper)}
.rail-link[aria-current="page"] .rail-link__code{color:var(--copper-light)}
.rail-nav__foot{margin-top:auto;padding-top:14px;border-top:1px solid var(--line-soft);font-size:12px;line-height:1.75;color:var(--gray-400)}
.rail-nav__cta{align-self:flex-start}

/* ---------- footer ---------- */
.site-footer{
  margin-top:clamp(40px,6vw,84px);
  padding-block:clamp(34px,5vw,64px) 22px;
  border-top:1px solid var(--line);
  background:linear-gradient(180deg,rgba(11,22,34,.55),rgba(18,36,54,.92));
}
.footer-grid{display:grid;gap:clamp(24px,3vw,40px);grid-template-columns:1fr}
.footer-brand__name{font-family:var(--font-head);font-size:20px;font-weight:650;letter-spacing:.02em}
.footer-brand__summary{margin-top:10px;max-width:36ch;font-size:14px;color:var(--gray-400)}
.footer-brand__badge{display:inline-flex;align-items:center;gap:8px;margin-top:16px;padding:6px 13px;border:1px dashed rgba(216,195,154,.32);border-radius:var(--r-pill);font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--copper-light)}
.footer-col__title{margin-bottom:14px;font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--copper)}
.footer-list{display:flex;flex-direction:column;gap:9px}
.footer-list a{font-size:14px;color:rgba(237,231,219,.8);border-bottom:1px solid transparent;transition:color var(--dur-1) var(--ease),border-color var(--dur-1) var(--ease)}
.footer-list a:hover{color:var(--copper-light);border-bottom-color:rgba(192,139,62,.55)}
.footer-list a[aria-current="page"]{color:var(--ivory);border-bottom-color:var(--cinnabar)}
.footer-contact__list{display:flex;flex-direction:column;gap:12px}
.footer-contact__row{display:flex;flex-direction:column;gap:2px}
.footer-contact__label{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--gray-400)}
.footer-contact__value{font-family:var(--font-mono);font-size:13px;line-height:1.7;color:rgba(237,231,219,.88);word-break:break-word}
.footer-bottom{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 22px;margin-top:clamp(26px,4vw,44px);padding-top:18px;border-top:1px solid var(--line-soft);font-size:12.5px;color:var(--gray-400)}
.footer-legal{font-family:var(--font-mono);letter-spacing:.06em}
.footer-note{color:var(--gray-400)}

/* ---------- progress & reveal ---------- */
.scroll-progress{position:fixed;top:0;inset-inline:0;height:2px;z-index:100;pointer-events:none}
.scroll-progress__fill{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--copper),var(--copper-light));transition:width 90ms linear}
html[data-reveal-ready] [data-reveal]{opacity:0;transform:translateY(10px)}
[data-reveal]{transition:opacity var(--dur-3) var(--ease),transform var(--dur-3) var(--ease)}
html[data-reveal-ready] [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- breakpoints ---------- */
@media (min-width:700px){
  .grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:760px){
  .footer-grid{grid-template-columns:1.4fr 1fr 1fr}
  .footer-brand{align-self:start}
}
@media (min-width:900px){
  .masthead__note{display:block}
  .masthead__utils{display:flex}
}
@media (min-width:1024px){
  body{padding-inline-start:var(--rail-w)}
  .site-header{
    position:fixed;inset-block:0;inset-inline-start:0;
    display:flex;flex-direction:column;width:var(--rail-w);
    border-bottom:0;border-inline-end:1px solid var(--line);
    background:linear-gradient(180deg,rgba(11,22,34,.99),rgba(18,36,54,.92));
    overflow-y:auto;
  }
  .site-header[data-open]::before{content:none}
  .masthead{flex-direction:column;align-items:flex-start;gap:14px;min-height:0;padding:26px 22px 18px;border-bottom:1px solid var(--line-soft)}
  .masthead__note{font-size:12px;max-width:26ch}
  .masthead__utils{flex-direction:column;align-items:flex-start;gap:12px;margin-inline-start:0}
  .utility-nav{flex-direction:column;gap:8px}
  .nav-toggle{display:none}
  .rail-nav{position:static;transform:none;visibility:visible;width:auto;height:auto;flex:1;gap:14px;padding:20px 16px 26px;border-inline-start:0;background:transparent;overflow:visible}
  .rail-nav__foot{margin-top:auto}
  .scroll-progress{inset-inline-start:var(--rail-w)}
  .grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
  .grid--asym{grid-template-columns:1.35fr .9fr}
  .footer-grid{grid-template-columns:1.5fr 1fr 1fr 1.2fr}
}
@media (min-width:1280px){
  :root{--gutter:clamp(24px,4vw,56px)}
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms !important;animation-iteration-count:1 !important;transition-duration:.01ms !important}
  html{scroll-behavior:auto}
  html[data-reveal-ready] [data-reveal]{opacity:1;transform:none}
  .rail-nav{transition:none}
  .scroll-progress__fill{transition:none}
}