/* ===== 0. Reset ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body,h1,h2,h3,h4,p,figure,blockquote,dl,dd,ul,ol{margin:0}
ul[class],ol[class]{list-style:none;padding:0}
img,svg,video{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:900;letter-spacing:.08em;line-height:1.18;color:var(--ink);text-wrap:balance}

/* ===== 1. Tokens ===== */
:root{
  --ink:#12233A;
  --ink-2:#1E3A5C;
  --ink-3:#0B1826;
  --paper:#F5F1E8;
  --paper-2:#FBF8F1;
  --slate:#DDE3EA;
  --gold:#C39A4E;
  --gold-soft:#E4C988;
  --gold-ink:#8A6A28;
  --celadon:#4E7F72;
  --sand:#D9A87C;
  --alert:#A34A3C;
  --text:#1B1F26;
  --muted:#5C6674;

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

  --shell-max:1320px;
  --gutter:clamp(18px,4vw,44px);
  --radius-s:8px;
  --radius-m:14px;
  --radius-l:22px;
  --ease:cubic-bezier(.4,0,.2,1);
  --hair-gold:1px solid rgba(195,154,78,.34);
  --hair-ink:1px solid rgba(18,35,58,.14);
}

/* ===== 2. Base ===== */
html{scroll-padding-top:96px}
body{
  display:flex;
  flex-direction:column;
  min-height:100dvh;
  background-color:var(--paper);
  background-image:radial-gradient(rgba(18,35,58,.045) 1px,transparent 1px);
  background-size:4px 4px;
  color:var(--text);
  font-family:var(--font-serif);
  font-size:1.0625rem;
  line-height:1.85;
  letter-spacing:.01em;
}
#main-content{flex:1 0 auto}
:focus-visible{outline:2px solid var(--gold);outline-offset:3px;border-radius:2px}
::selection{background:var(--gold-soft);color:var(--ink)}

/* ===== 3. Skip link ===== */
.skip-link{
  position:fixed;top:0;left:50%;z-index:200;
  transform:translate(-50%,-140%);
  padding:12px 24px;
  background:var(--gold);color:var(--ink);
  font-family:var(--font-display);font-weight:700;font-size:.8125rem;letter-spacing:.16em;
  border-radius:0 0 var(--radius-s) var(--radius-s);
  transition:transform .18s var(--ease);
}
.skip-link:focus,.skip-link:focus-visible{transform:translate(-50%,0);outline:2px solid var(--ink);outline-offset:-4px}

/* ===== 4. Header ===== */
.site-header{
  position:sticky;top:0;z-index:80;
  background:var(--ink);
  color:var(--paper);
  border-bottom:var(--hair-gold);
  box-shadow:0 18px 34px -30px rgba(6,14,24,.9);
}
.scroll-progress{
  position:absolute;left:0;right:0;bottom:0;height:2px;
  background:rgba(195,154,78,.14);
  pointer-events:none;
}
.scroll-progress__bar{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--gold),var(--gold-soft));
}
.header-shell{
  display:flex;align-items:center;
  gap:clamp(14px,2.2vw,30px);
  width:100%;max-width:var(--shell-max);
  margin-inline:auto;
  padding:clamp(12px,1.5vw,17px) var(--gutter);
}
.brand{display:flex;align-items:center;gap:13px;flex:0 0 auto;border-radius:var(--radius-s)}
.brand__mark{
  display:grid;place-items:center;flex:0 0 auto;
  width:44px;height:44px;
  border:1px solid rgba(195,154,78,.62);
  border-radius:13px 5px 13px 5px;
  color:var(--gold-soft);
  font-family:var(--font-mono);font-size:.8125rem;letter-spacing:.08em;
  background:rgba(195,154,78,.08);
  transition:border-color .18s var(--ease),background-color .18s var(--ease);
}
.brand:hover .brand__mark{border-color:var(--gold);background:rgba(195,154,78,.18)}
.brand__text{display:flex;flex-direction:column;gap:3px;min-width:0}
.brand__line{
  font-family:var(--font-display);font-weight:900;font-size:1.0625rem;
  letter-spacing:.16em;line-height:1.15;color:var(--paper);white-space:nowrap;
}
.brand__sub{
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.12em;
  line-height:1.3;color:rgba(245,241,232,.55);white-space:nowrap;
}
.header__rule{
  flex:1 1 auto;height:1px;min-width:24px;
  background:linear-gradient(90deg,rgba(195,154,78,.55),rgba(195,154,78,0));
}
.header__panel{display:flex;align-items:center;gap:clamp(14px,2vw,26px);flex:0 0 auto}
.header__index-label{
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.18em;
  color:var(--gold);
  padding-right:16px;border-right:1px solid rgba(195,154,78,.26);
}
.site-nav{display:flex}
.nav-list{display:flex;align-items:center;gap:clamp(10px,1.5vw,22px)}
.nav-link{
  position:relative;display:inline-block;padding:6px 1px;
  font-family:var(--font-display);font-weight:500;font-size:.8125rem;letter-spacing:.14em;
  color:rgba(245,241,232,.82);white-space:nowrap;
  transition:color .18s var(--ease);
}
.nav-link::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:1px;
  background:var(--gold);transform:scaleX(0);transform-origin:0 50%;
  transition:transform .18s var(--ease);
}
.nav-link:hover,.nav-link:focus-visible{color:var(--gold-soft)}
.nav-link:hover::after,.nav-link:focus-visible::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--gold-soft)}
.nav-link[aria-current="page"]::after{transform:scaleX(1);height:2px;background:var(--gold)}
.header__cta{
  display:inline-flex;align-items:center;gap:8px;
  padding:9px 16px;
  border:1px solid rgba(195,154,78,.55);
  border-radius:999px;
  font-family:var(--font-display);font-weight:500;font-size:.75rem;letter-spacing:.16em;
  color:var(--gold-soft);white-space:nowrap;
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.header__cta::before{
  content:"";width:5px;height:5px;border-radius:1px;
  background:currentColor;transform:rotate(45deg);
}
.header__cta:hover,.header__cta:focus-visible{background:var(--gold);border-color:var(--gold);color:var(--ink)}
.nav-toggle{
  display:none;align-items:center;gap:10px;
  margin-left:auto;
  padding:9px 14px;
  background:transparent;
  border:1px solid rgba(195,154,78,.5);
  border-radius:999px;
  color:var(--gold-soft);cursor:pointer;
  transition:border-color .18s var(--ease),background-color .18s var(--ease);
}
.nav-toggle:hover{background:rgba(195,154,78,.14);border-color:var(--gold)}
.nav-toggle__bars{display:flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle__bars span{display:block;height:1px;background:currentColor;transition:transform .18s var(--ease),opacity .18s var(--ease)}
.nav-toggle__label{font-family:var(--font-display);font-size:.75rem;letter-spacing:.16em}
.site-header[data-open] .nav-toggle__bars span:nth-child(1){transform:translateY(5px) rotate(45deg)}
.site-header[data-open] .nav-toggle__bars span:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle__bars span:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

/* ===== 5. Footer ===== */
.site-footer{
  background:var(--ink);
  color:rgba(245,241,232,.78);
  border-top:var(--hair-gold);
  padding:clamp(40px,6vw,76px) 0 clamp(22px,3vw,32px);
}
.footer-shell{
  width:100%;max-width:var(--shell-max);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr 1.45fr;
  gap:clamp(24px,3.2vw,54px);
  padding-bottom:clamp(26px,4vw,46px);
  border-bottom:1px solid rgba(195,154,78,.22);
}
.footer-identity{min-width:0}
.footer-brand{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-display);font-weight:900;font-size:1.0625rem;letter-spacing:.16em;
  color:var(--paper);
  transition:color .18s var(--ease);
}
.footer-brand::before{
  content:"";width:9px;height:9px;flex:0 0 auto;
  border:1px solid var(--gold);transform:rotate(45deg);
}
.footer-brand:hover{color:var(--gold-soft)}
.footer-sub{
  margin-top:12px;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.16em;
  color:rgba(245,241,232,.48);
}
.footer-note{
  margin-top:16px;max-width:32ch;
  font-size:.9375rem;line-height:1.8;
  color:rgba(245,241,232,.6);
}
.footer-col{min-width:0}
.footer-col-title{
  display:flex;align-items:center;gap:10px;
  margin-bottom:16px;
  font-family:var(--font-display);font-weight:500;font-size:.75rem;letter-spacing:.18em;
  color:var(--gold);
}
.footer-col-title::after{content:"";flex:1 1 auto;height:1px;background:rgba(195,154,78,.26)}
.footer-links{display:flex;flex-direction:column;gap:9px}
.footer-link{
  display:inline-block;
  font-size:.9375rem;line-height:1.6;
  color:rgba(245,241,232,.76);
  transition:color .18s var(--ease),transform .18s var(--ease);
}
.footer-link:hover,.footer-link:focus-visible{color:var(--gold-soft);transform:translateX(3px)}
.footer-contact{display:flex;flex-direction:column;gap:11px;min-width:0}
.footer-contact-item{display:flex;gap:10px;align-items:baseline;font-size:.9375rem;line-height:1.7}
.footer-contact-label{
  flex:0 0 auto;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.12em;
  color:rgba(195,154,78,.9);
}
.footer-contact-value{color:rgba(245,241,232,.82);word-break:break-word}
.footer-contact-note{
  margin-top:2px;
  font-size:.8125rem;line-height:1.8;
  color:rgba(245,241,232,.46);
}
.footer-base{
  display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;
  gap:14px 28px;
  padding-top:clamp(18px,2.4vw,28px);
  font-family:var(--font-mono);font-size:.75rem;letter-spacing:.08em;
  color:rgba(245,241,232,.46);
}
.footer-legal{max-width:54ch;line-height:1.75}
.footer-meta{display:flex;flex-wrap:wrap;gap:6px 20px}
.footer-copy{color:rgba(245,241,232,.5)}
.footer-icp{color:rgba(228,201,136,.78)}

/* ===== 6. Layout atoms ===== */
.shell{width:100%;max-width:var(--shell-max);margin-inline:auto;padding-inline:var(--gutter)}
.shell--narrow{max-width:72ch}
.section{padding-block:clamp(38px,6vw,84px)}
.section--ink{background:var(--ink);color:rgba(245,241,232,.8)}
.section--slate{background:var(--slate)}
.section__head{
  display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;
  gap:10px 28px;
  margin-bottom:clamp(20px,3vw,34px);
  padding-bottom:14px;
  border-bottom:var(--hair-ink);
}
.section__title{font-size:clamp(1.375rem,2.4vw,1.75rem);letter-spacing:.08em}
.section__note{font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.14em;color:var(--muted)}
.section--ink .section__head{border-bottom-color:rgba(195,154,78,.26)}
.section--ink .section__title{color:var(--paper)}
.section--ink .section__note{color:rgba(245,241,232,.58)}

.grid{display:grid;gap:clamp(14px,2vw,24px)}
.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(0,62fr) minmax(0,34fr);gap:clamp(20px,3.4vw,44px)}

/* ===== 7. Typography helpers ===== */
.u-label{
  display:inline-block;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.18em;
  color:var(--gold-ink);
}
.u-mono{font-family:var(--font-mono);font-size:.8125rem;letter-spacing:.06em}
.prose{max-width:70ch;font-family:var(--font-serif);font-size:1.0625rem;line-height:1.9;color:var(--text)}
.prose>*+*{margin-top:1.05em}
.prose h2{margin-top:2.1em;font-size:clamp(1.375rem,2.4vw,1.75rem)}
.prose h3{margin-top:1.7em;font-size:1.1875rem}
.prose ul,.prose ol{padding-left:1.4em}
.prose ul{list-style:square}
.prose ol{list-style:decimal}
.prose li+li{margin-top:.45em}
.prose a{color:var(--gold-ink);text-decoration:underline;text-underline-offset:3px}
.prose a:hover{color:var(--ink)}
.prose blockquote{border-left:2px solid var(--gold);padding-left:18px;color:var(--muted)}
.prose strong{font-weight:700;color:var(--ink)}

/* ===== 8. Buttons ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:12px 22px;
  font-family:var(--font-display);font-weight:500;font-size:.8125rem;letter-spacing:.14em;
  border:1px solid transparent;border-radius:999px;cursor:pointer;
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease);
}
.btn--gold{background:var(--gold);color:var(--ink);border-color:var(--gold)}
.btn--gold:hover{background:var(--gold-soft);border-color:var(--gold-soft);transform:translateY(-2px)}
.btn--outline{background:transparent;color:var(--ink);border-color:rgba(18,35,58,.28)}
.btn--outline:hover{border-color:var(--gold);color:var(--gold-ink);transform:translateY(-2px)}
.btn--ink{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn--ink:hover{background:var(--ink-2);border-color:var(--ink-2);transform:translateY(-2px)}

/* ===== 9. Breadcrumbs ===== */
.crumbs{padding-block:14px;border-bottom:var(--hair-ink)}
.crumbs__list{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.1em;
  color:var(--muted);
}
.crumbs__link{color:var(--muted);transition:color .18s var(--ease)}
.crumbs__link:hover,.crumbs__link:focus-visible{color:var(--gold-ink)}
.crumbs__sep{color:rgba(18,35,58,.28)}
.crumbs__current{color:var(--ink)}

/* ===== 10. Card / Tag ===== */
.card{
  position:relative;display:flex;flex-direction:column;gap:9px;
  padding:clamp(18px,2.3vw,28px);
  background:var(--paper-2);
  border:1px solid rgba(18,35,58,.14);
  border-radius:var(--radius-m);
  transition:transform .18s var(--ease),border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.card:hover,.card:focus-within{
  transform:translateY(-3px);
  border-color:var(--gold);
  box-shadow:0 18px 34px -24px rgba(18,35,58,.55);
}
.card__index{font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.14em;color:var(--gold-ink)}
.card__title{font-family:var(--font-display);font-weight:700;font-size:1.0625rem;letter-spacing:.05em;line-height:1.45;color:var(--ink)}
.card__text{font-size:.9375rem;line-height:1.8;color:var(--muted)}
.card__more{
  margin-top:auto;padding-top:8px;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.14em;
  color:var(--gold-ink);
  transition:color .18s var(--ease);
}
.card__more::after{content:" →"}
.card:hover .card__more{color:var(--ink)}
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 11px;border-radius:999px;border:1px solid currentColor;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.08em;
  background:transparent;
}
.tag--gold{color:#7E6023;background:rgba(195,154,78,.12);border-color:rgba(195,154,78,.45)}
.tag--celadon{color:#2F5A4E;background:rgba(78,127,114,.12);border-color:rgba(78,127,114,.42)}
.tag--sand{color:#8A5A2C;background:rgba(217,168,124,.16);border-color:rgba(217,168,124,.5)}

/* ===== 11. Media frames ===== */
.media-frame{
  position:relative;display:block;overflow:hidden;
  aspect-ratio:16/10;
  background:var(--ink-2);
  border:1px solid rgba(18,35,58,.16);
  border-radius:var(--radius-m);
}
.media-frame>img,.media-frame picture>img{
  width:100%;height:100%;object-fit:cover;
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--square{aspect-ratio:1/1}
.media-frame__caption{
  position:absolute;left:0;bottom:0;max-width:100%;
  padding:7px 13px;
  background:rgba(11,24,38,.82);
  color:rgba(245,241,232,.86);
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.1em;
  border-top-right-radius:var(--radius-s);
}

/* ===== 12. Reveal protocol ===== */
[data-reveal]{transition:opacity .42s var(--ease),transform .42s var(--ease)}
html.js [data-reveal]:not([data-revealed]){opacity:0;transform:translateY(10px)}

/* ===== 13. Responsive ===== */
@media (max-width:1080px){
  .header__rule{display:none}
  .nav-toggle{display:inline-flex}
  .header__panel{
    position:absolute;top:100%;left:0;right:0;
    display:none;flex-direction:column;align-items:stretch;gap:0;
    padding:16px var(--gutter) 26px;
    background:var(--ink-2);
    border-bottom:1px solid var(--gold);
    box-shadow:0 30px 48px -30px rgba(6,14,24,.95);
    max-height:calc(100dvh - 76px);
    overflow-y:auto;
  }
  .site-header[data-open] .header__panel{display:flex}
  .header__index-label{
    display:block;
    padding:0 0 12px;margin-bottom:6px;
    border-right:0;border-bottom:1px solid rgba(195,154,78,.22);
    letter-spacing:.2em;
  }
  .site-nav{display:block}
  .nav-list{flex-direction:column;align-items:stretch;gap:0}
  .nav-list li+li{border-top:1px solid rgba(195,154,78,.14)}
  .nav-link{display:block;padding:15px 2px;font-size:.9375rem;letter-spacing:.12em}
  .nav-link::after{display:none}
  .nav-link:hover,.nav-link:focus-visible{color:var(--gold-soft)}
  .nav-link[aria-current="page"]{
    color:var(--gold-soft);
    padding-left:14px;
    box-shadow:inset 2px 0 0 var(--gold);
  }
  .header__cta{align-self:flex-start;margin-top:20px}
  body.nav-open{overflow:hidden}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-identity{grid-column:1/-1}
}
@media (max-width:900px){
  .grid--2,.grid--3,.grid--split{grid-template-columns:minmax(0,1fr)}
  .prose{font-size:1rem}
}
@media (max-width:620px){
  .header-shell{padding-block:11px}
  .brand__mark{width:38px;height:38px;font-size:.75rem}
  .brand__line{font-size:.9375rem;letter-spacing:.12em}
  .brand__sub{font-size:.625rem;letter-spacing:.08em}
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:26px}
  .footer-identity{grid-column:auto}
  .footer-base{flex-direction:column;align-items:flex-start}
  .media-frame--tall{aspect-ratio:4/5}
}

/* ===== 14. Motion preferences ===== */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  html.js [data-reveal]:not([data-revealed]){opacity:1;transform:none}
  .card:hover,.card:focus-within,.btn:hover,.footer-link:hover,.footer-link:focus-visible{transform:none}
}