/* ===== reset ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:132px}
body,h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
a{color:inherit}
button{font:inherit;color:inherit}
:where(h1,h2,h3,h4){font-weight:800}
main{display:block}

/* ===== tokens ===== */
:root{
  --ink-900:#0A1522;
  --ink-800:#101F33;
  --ink-700:#17293F;
  --helan-slate:#6E7F8C;
  --sand-gold:#D9B26A;
  --amber-orange:#FF8A2B;
  --paper-sand:#F2E7D5;
  --muted-paper:#B9AE9C;
  --archive-line:#2B3F55;
  --status-jade:#4F9D82;

  --shell-max:1240px;
  --gutter:clamp(18px,4vw,48px);
  --radius:3px;
  --ease:cubic-bezier(.22,.61,.36,1);

  --font-display:"PingFang SC","HarmonyOS Sans SC","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"PingFang SC","Hiragino Sans GB","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:ui-monospace,"SFMono-Regular","JetBrains Mono",Consolas,"Liberation Mono",monospace;
}

/* ===== base ===== */
html{background:var(--ink-900)}
body{
  min-height:100vh;
  background-color:var(--ink-900);
  background-image:
    radial-gradient(1200px 520px at 10% -12%,rgba(217,178,106,.11),transparent 62%),
    radial-gradient(900px 480px at 98% 2%,rgba(110,127,140,.16),transparent 60%);
  background-repeat:no-repeat;
  color:var(--paper-sand);
  font-family:var(--font-body);
  font-size:clamp(15px,.35vw + 14px,17px);
  line-height:1.85;
  letter-spacing:.01em;
}
::selection{background:var(--amber-orange);color:var(--ink-900)}
:focus-visible{outline:2px solid var(--amber-orange);outline-offset:3px}

h1,h2,h3,h4{
  font-family:var(--font-display);
  line-height:1.06;
  letter-spacing:.02em;
  color:var(--paper-sand);
}
h1{font-size:clamp(2.4rem,6vw,5.4rem)}
h2{font-size:clamp(1.7rem,3.4vw,2.9rem)}
h3{font-size:clamp(1.2rem,2vw,1.6rem);line-height:1.28}
p{max-width:72ch}

/* ===== utilities ===== */
.shell{
  width:100%;
  max-width:var(--shell-max);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.mono{font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;font-variant-numeric:tabular-nums}
.eyebrow{
  display:inline-block;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.3em;
  text-transform:uppercase;
  color:var(--sand-gold);
}
.chip{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 10px;
  border:1px solid var(--archive-line);
  border-radius:999px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--muted-paper);
  background:rgba(23,41,63,.6);
}
.lede{
  font-size:clamp(1.05rem,1.5vw,1.28rem);
  line-height:1.72;
  color:#E5DAC8;
  max-width:60ch;
}
.prose{max-width:68ch}
.prose p + p{margin-top:1.2em}
.prose h2,.prose h3{margin-top:1.9em;margin-bottom:.6em}
.prose ul,.prose ol{list-style:none;max-width:68ch}
.prose li{position:relative;padding-left:1.5em;margin-top:.55em;color:#E1D6C4}
.prose li::before{content:"—";position:absolute;left:0;color:var(--helan-slate)}
.divider{height:1px;border:0;background:var(--archive-line);margin-block:clamp(28px,4vw,56px)}

.grid{display:grid;gap:clamp(20px,3vw,40px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--split{grid-template-columns:minmax(0,7fr) minmax(0,5fr)}
.grid--aside{grid-template-columns:minmax(200px,260px) minmax(0,1fr)}

/* ===== buttons ===== */
.btn{
  display:inline-flex;
  align-items:center;
  gap:10px;
  padding:12px 22px;
  border:1px solid var(--archive-line);
  border-radius:var(--radius);
  font-size:14px;
  letter-spacing:.08em;
  text-decoration:none;
  color:var(--paper-sand);
  background:transparent;
  cursor:pointer;
  transition:background-color .24s var(--ease),border-color .24s var(--ease),color .24s var(--ease),transform .24s var(--ease);
}
.btn:hover{transform:translateY(-1px)}
.btn--primary{
  background:var(--amber-orange);
  border-color:var(--amber-orange);
  color:#140E07;
  font-weight:700;
}
.btn--primary:hover{background:#FF9C4E;border-color:#FF9C4E}
.btn--ghost{
  border-color:var(--helan-slate);
  color:var(--paper-sand);
}
.btn--ghost:hover{border-color:var(--sand-gold);color:var(--sand-gold)}

/* ===== breadcrumb ===== */
.breadcrumb{margin-block:clamp(20px,3vw,34px) 0}
.breadcrumb__list{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--helan-slate)}
.breadcrumb__item{display:flex;align-items:center;gap:8px}
.breadcrumb__item + .breadcrumb__item::before{content:"/";color:var(--archive-line)}
.breadcrumb__link{color:var(--muted-paper);text-decoration:none;border-bottom:1px solid transparent}
.breadcrumb__link:hover{color:var(--sand-gold);border-bottom-color:var(--sand-gold)}
.breadcrumb__item[aria-current="page"]{color:var(--paper-sand)}

/* ===== media frame ===== */
.media-frame{
  --media-ratio:4/3;
  position:relative;
  overflow:hidden;
  aspect-ratio:var(--media-ratio);
  border:1px solid var(--archive-line);
  border-radius:var(--radius);
  background-color:var(--ink-700);
  background-image:
    repeating-linear-gradient(135deg,rgba(110,127,140,.13) 0 1px,transparent 1px 14px),
    radial-gradient(120% 90% at 18% 8%,rgba(217,178,106,.22),transparent 60%),
    linear-gradient(160deg,var(--ink-800),var(--ink-900));
}
.media-frame img{width:100%;height:100%;object-fit:cover}
.media-frame--wide{--media-ratio:16/9}
.media-frame--tall{--media-ratio:3/4}
.media-frame__caption{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  padding:10px 14px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--muted-paper);
  background:linear-gradient(to top,rgba(10,21,34,.92),rgba(10,21,34,0));
}

/* ===== header ===== */
.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:var(--ink-800);
  border-bottom:1px solid var(--archive-line);
  box-shadow:0 18px 40px -32px rgba(0,0,0,.9);
}
.skip-link{
  position:absolute;
  left:var(--gutter);
  top:-72px;
  z-index:99;
  padding:10px 18px;
  background:var(--sand-gold);
  color:var(--ink-900);
  font-size:13px;
  letter-spacing:.06em;
  text-decoration:none;
  border-radius:0 0 var(--radius) var(--radius);
  transition:top .2s var(--ease);
}
.skip-link:focus{top:0}

.header-top{background:var(--ink-900);border-bottom:1px solid var(--archive-line)}
.header-top__inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:24px;
  min-height:38px;
}
.header-top__status{
  display:flex;
  align-items:center;
  gap:10px;
  font-size:12px;
  letter-spacing:.06em;
  color:var(--muted-paper);
  max-width:none;
}
.header-top__status .mono{color:var(--sand-gold)}
.status-dot{
  width:7px;
  height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--status-jade);
  box-shadow:0 0 0 4px rgba(79,157,130,.16);
}
.header-top__text{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.utility-nav{display:flex;align-items:center;gap:22px}
.utility-nav__link{
  font-size:12px;
  letter-spacing:.16em;
  color:var(--helan-slate);
  text-decoration:none;
  padding-bottom:2px;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.utility-nav__link:hover{color:var(--sand-gold);border-bottom-color:var(--sand-gold)}

.header-main{position:relative}
.header-main__inner{
  display:flex;
  align-items:center;
  gap:clamp(14px,2vw,30px);
  min-height:76px;
}
.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  text-decoration:none;
  color:var(--paper-sand);
  flex:0 0 auto;
}
.brand__mark{
  display:grid;
  gap:3px;
  width:22px;
  flex:0 0 auto;
}
.brand__mark span{display:block;height:3px;border-radius:1px}
.brand__mark span:nth-child(1){width:100%;background:var(--amber-orange)}
.brand__mark span:nth-child(2){width:72%;background:var(--sand-gold)}
.brand__mark span:nth-child(3){width:46%;background:var(--helan-slate)}
.brand__name{
  font-family:var(--font-display);
  font-size:23px;
  font-weight:800;
  letter-spacing:.05em;
  line-height:1;
}
.brand__sub{
  font-size:11px;
  letter-spacing:.28em;
  color:var(--sand-gold);
  padding-left:10px;
  border-left:1px solid var(--archive-line);
  line-height:1.4;
}
.brand:hover .brand__sub{color:var(--paper-sand)}

.primary-nav{margin-left:auto}
.primary-nav__list{display:flex;align-items:center;gap:2px}
.nav-link{
  display:flex;
  align-items:baseline;
  gap:7px;
  padding:10px 13px;
  border-left:2px solid transparent;
  border-radius:2px;
  font-size:14px;
  letter-spacing:.05em;
  color:var(--muted-paper);
  text-decoration:none;
  white-space:nowrap;
  transition:color .2s var(--ease),background-color .2s var(--ease),border-color .2s var(--ease);
}
.nav-link__index{font-size:10px;color:var(--helan-slate);letter-spacing:.06em}
.nav-link:hover{color:var(--paper-sand);background:rgba(242,231,213,.05)}
.nav-link:hover .nav-link__index{color:var(--sand-gold)}
.nav-link[aria-current="page"]{color:var(--paper-sand);background:rgba(242,231,213,.06)}
.nav-link[aria-current="page"] .nav-link__index{color:var(--sand-gold)}
.nav-link.is-anchor{
  color:var(--sand-gold);
  background:rgba(255,138,43,.09);
  border-left-color:var(--amber-orange);
}
.nav-link.is-anchor .nav-link__index{color:var(--amber-orange)}
.nav-link.is-anchor:hover{background:rgba(255,138,43,.16);color:var(--paper-sand)}
.nav-link.is-anchor[aria-current="page"]{
  background:rgba(255,138,43,.2);
  color:#FFD9B0;
  border-left-color:var(--amber-orange);
}

.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  margin-left:auto;
  padding:9px 13px;
  background:transparent;
  border:1px solid var(--archive-line);
  border-radius:var(--radius);
  color:var(--paper-sand);
  font-size:12px;
  letter-spacing:.18em;
  cursor:pointer;
}
.nav-toggle:hover{border-color:var(--sand-gold)}
.nav-toggle__bars{display:grid;gap:4px;width:16px}
.nav-toggle__bars span{display:block;height:2px;background:var(--sand-gold);transition:transform .24s var(--ease)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child{transform:translateY(3px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child{transform:translateY(-3px) rotate(-45deg)}
.nav-toggle__label{line-height:1}

.scroll-rail{
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:2px;
  background:rgba(43,63,85,.55);
  overflow:hidden;
}
.scroll-rail__fill{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--sand-gold),var(--amber-orange));
  transition:width .12s linear;
}

/* ===== footer ===== */
.site-footer{
  position:relative;
  margin-top:clamp(64px,10vw,140px);
  padding-top:clamp(40px,6vw,72px);
  background:var(--ink-800);
  border-top:1px solid var(--archive-line);
}
.site-footer::before{
  content:"";
  position:absolute;
  inset:0 0 auto 0;
  height:3px;
  background:linear-gradient(90deg,var(--sand-gold),var(--amber-orange) 34%,rgba(43,63,85,0) 78%);
}
.footer-main{
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,2.1fr);
  gap:clamp(32px,5vw,72px);
  padding-bottom:clamp(36px,5vw,56px);
}
.footer-brand__logo{margin-bottom:18px}
.footer-brand__summary{
  font-size:14px;
  line-height:1.85;
  color:var(--muted-paper);
  max-width:34ch;
}
.footer-brand__note{
  margin-top:14px;
  font-size:12px;
  line-height:1.75;
  color:var(--helan-slate);
  max-width:36ch;
}
.footer-brand .eyebrow{margin-top:18px}
.footer-cols{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(20px,3vw,40px);
}
.footer-col__title{
  display:block;
  padding-bottom:10px;
  margin-bottom:16px;
  border-bottom:1px solid var(--archive-line);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.24em;
  color:var(--sand-gold);
}
.footer-list{display:grid;gap:10px}
.footer-link{
  display:inline-block;
  font-size:14px;
  color:var(--muted-paper);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease);
}
.footer-link:hover{color:var(--paper-sand);border-bottom-color:var(--sand-gold);transform:translateX(2px)}

.footer-contact{gap:14px}
.footer-contact__line{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:4px 8px;
  font-size:13px;
  line-height:1.65;
}
.footer-contact__label{
  font-size:10px;
  letter-spacing:.2em;
  color:var(--helan-slate);
  min-width:30px;
}
.footer-contact__value{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.02em;
  color:var(--paper-sand);
  word-break:break-all;
}
.footer-contact__text{
  flex:1 1 100%;
  font-size:12.5px;
  line-height:1.7;
  color:var(--muted-paper);
}
.copy-btn{
  padding:3px 8px;
  background:transparent;
  border:1px solid var(--archive-line);
  border-radius:2px;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.14em;
  color:var(--helan-slate);
  cursor:pointer;
  transition:color .2s var(--ease),border-color .2s var(--ease),background-color .2s var(--ease);
}
.copy-btn:hover{color:var(--amber-orange);border-color:var(--amber-orange)}
.copy-btn[data-copied="true"]{
  color:var(--ink-900);
  background:var(--status-jade);
  border-color:var(--status-jade);
}

.footer-legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 24px;
  padding-block:20px 34px;
  border-top:1px solid var(--archive-line);
  font-size:12px;
  color:var(--helan-slate);
}
.footer-legal__copy{max-width:none;letter-spacing:.04em}
.footer-legal__copy .mono{color:var(--muted-paper)}
.footer-legal__links{display:flex;flex-wrap:wrap;gap:18px}
.footer-legal__link{
  color:var(--helan-slate);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-legal__link:hover{color:var(--sand-gold);border-bottom-color:var(--sand-gold)}

/* ===== responsive ===== */
@media (max-width:1100px){
  .nav-link{padding:10px 9px;font-size:13px}
  .nav-link__index{display:none}
}
@media (max-width:960px){
  html{scroll-padding-top:112px}
  .header-top__inner{justify-content:center;min-height:32px}
  .header-top__text{display:none}
  .utility-nav{display:none}
  .header-main__inner{min-height:64px;gap:12px}
  .brand__name{font-size:20px}
  .brand__sub{font-size:10px;letter-spacing:.2em;padding-left:8px}
  .nav-toggle{display:inline-flex}
  .primary-nav{
    position:absolute;
    left:0;
    right:0;
    top:100%;
    margin-left:0;
    background:var(--ink-800);
    border-top:1px solid var(--archive-line);
    border-bottom:1px solid var(--archive-line);
    max-height:0;
    overflow:hidden;
    transition:max-height .28s var(--ease);
  }
  .primary-nav[data-open]{max-height:min(72vh,560px);overflow-y:auto}
  .primary-nav__list{flex-direction:column;align-items:stretch;gap:0;padding:4px 0 12px}
  .nav-link{
    padding:14px var(--gutter);
    font-size:15px;
    border-left:2px solid transparent;
    border-bottom:1px solid var(--archive-line);
    border-radius:0;
  }
  .nav-link__index{display:inline}
  .nav-link.is-anchor{border-left-color:var(--amber-orange)}
  .grid--2,.grid--split,.grid--aside{grid-template-columns:minmax(0,1fr)}
  .footer-main{grid-template-columns:minmax(0,1fr)}
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:600px){
  .footer-cols{grid-template-columns:minmax(0,1fr);gap:28px}
  .footer-legal{flex-direction:column;align-items:flex-start;gap:10px}
  .footer-legal__links{gap:14px}
  .brand__sub{display:none}
  .btn{width:100%;justify-content:center}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .btn:hover,.footer-link:hover{transform:none}
}