*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,h6,p,ul,ol,dl,dd,figure,blockquote,address{margin:0}
ul,ol{list-style:none;padding:0}
img,svg,video{display:block;max-width:100%;height:auto}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
address{font-style:normal}

:root{
  --sand:#F3E6D0;
  --paper:#FFF9EE;
  --ink:#1F2421;
  --azurite:#1F5F6B;
  --azurite-soft:#6FA3A8;
  --malachite:#3E6B4F;
  --ochre:#A65E2E;
  --cinnabar:#C43A2B;
  --cinnabar-deep:#9E2B1E;
  --indigo:#3D365C;
  --slate:#5B6B70;
  --line:rgba(31,36,33,.14);
  --line-strong:rgba(31,36,33,.32);
  --line-paper:rgba(255,249,238,.22);
  --font-serif:"Noto Serif SC","Songti SC","STSong","SimSun",serif;
  --font-sans:"Noto Sans SC","PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",monospace;
  --shell:1240px;
  --gutter:clamp(1rem,4vw,2.5rem);
  --radius:3px;
  --header-h:64px;
  --ease:cubic-bezier(.2,.7,.3,1);
}

body{
  min-height:100vh;
  background-color:var(--sand);
  background-image:
    repeating-linear-gradient(90deg,rgba(166,94,46,.055) 0 1px,transparent 1px 96px),
    repeating-linear-gradient(0deg,rgba(31,95,107,.045) 0 1px,transparent 1px 96px);
  background-attachment:fixed;
  color:var(--ink);
  font-family:var(--font-sans);
  font-size:1rem;
  line-height:1.78;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3,h4{font-family:var(--font-serif);font-weight:800;line-height:1.18;letter-spacing:-.005em}
h1{font-size:clamp(2.2rem,5vw,4.8rem);line-height:1.06;letter-spacing:-.015em}
strong,b{font-weight:700}
.mono{font-family:var(--font-mono);letter-spacing:.02em}
.muted{color:var(--slate)}

:where(a,button,summary,[tabindex]):focus-visible{outline:2px solid var(--azurite);outline-offset:3px;border-radius:2px}
.site-footer :where(a,button):focus-visible{outline-color:var(--sand)}
:target{scroll-margin-top:calc(var(--header-h) + 1.5rem)}
#main-content{display:block}

.skip-link{
  position:fixed;top:0;left:0;z-index:300;
  transform:translateY(-160%);
  background:var(--ink);color:var(--paper);
  padding:.85rem 1.2rem;
  font-family:var(--font-mono);font-size:.8rem;letter-spacing:.12em;
  border-radius:0 0 var(--radius) 0;
  transition:transform 160ms var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* ============ header ============ */
.site-header{
  position:sticky;top:0;z-index:80;
  background:var(--paper);
  border-bottom:1px solid var(--line-strong);
  transition:box-shadow 200ms var(--ease);
}
.site-header[data-scrolled]{box-shadow:0 10px 26px -22px rgba(31,36,33,.85)}
.cmd-bar{
  position:relative;
  display:flex;align-items:stretch;
  width:min(calc(100% - var(--gutter) * 2),var(--shell));
  min-height:var(--header-h);
  margin-inline:auto;
}
.brand{
  display:flex;align-items:center;gap:.7rem;
  flex:0 0 auto;
  padding:.45rem 1.1rem .45rem .8rem;
  background:var(--azurite);
  color:var(--paper);
  transition:background-color 180ms var(--ease);
}
.brand:hover{background:#1A505A}
.brand-seal{
  display:grid;place-items:center;
  width:34px;height:34px;
  background:var(--cinnabar);color:var(--paper);
  font-family:var(--font-serif);font-weight:700;font-size:1.08rem;line-height:1;
  border-radius:2px;
  box-shadow:inset 0 0 0 1px rgba(255,249,238,.5);
}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-name{font-family:var(--font-serif);font-weight:800;font-size:1.02rem;letter-spacing:.16em}
.brand-tag{font-family:var(--font-mono);font-size:.62rem;letter-spacing:.34em;color:rgba(255,249,238,.72);margin-top:.25rem}

.site-nav{
  display:flex;align-items:center;gap:.35rem;
  flex:1 1 auto;min-width:0;
  padding-inline:clamp(.5rem,2vw,1.25rem);
}
.nav-cap{
  flex:0 0 auto;
  padding-right:.85rem;margin-right:.3rem;
  border-right:1px solid var(--line);
  font-family:var(--font-mono);font-size:.62rem;letter-spacing:.28em;
  color:var(--ochre);white-space:nowrap;
}
.nav-list{
  display:flex;align-items:center;gap:.1rem;
  flex-wrap:nowrap;overflow-x:auto;
  scrollbar-width:none;min-width:0;
}
.nav-list::-webkit-scrollbar{display:none}
.nav-item{flex:0 0 auto}
.nav-link{
  position:relative;
  display:inline-flex;align-items:center;gap:.42rem;
  padding:.62rem .62rem .78rem;
  font-size:.9rem;font-weight:500;color:var(--ink);
  transition:color 160ms var(--ease),background-color 160ms var(--ease);
}
.nav-idx{font-family:var(--font-mono);font-size:.6rem;letter-spacing:.06em;color:var(--ochre);transition:color 160ms var(--ease)}
.nav-label{white-space:nowrap}
.nav-link::after{
  content:"";position:absolute;left:.62rem;right:.62rem;bottom:.34rem;height:2px;
  background:var(--cinnabar);
  transform:scaleX(0);transform-origin:left center;
  transition:transform 180ms var(--ease);
}
.nav-link:hover{color:var(--azurite);background:rgba(31,95,107,.07)}
.nav-link:hover .nav-idx{color:var(--azurite)}
.nav-link:hover::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--ink);font-weight:700}
.nav-link[aria-current="page"] .nav-idx{color:var(--cinnabar)}
.nav-link[aria-current="page"]::after{transform:scaleX(1)}
.nav-cta{display:none}

.cmd-actions{
  display:flex;align-items:center;gap:.5rem;
  flex:0 0 auto;
  padding:.45rem .75rem .45rem .55rem;
  border-left:1px solid var(--line);
}
.nav-toggle{
  display:none;
  align-items:center;gap:.55rem;
  flex:0 0 auto;
  padding:0 .9rem;
  border-left:1px solid var(--line);
  color:var(--azurite);
  font-family:var(--font-mono);font-size:.7rem;letter-spacing:.18em;
}
.nav-toggle-bars{display:flex;flex-direction:column;gap:4px;width:18px}
.nav-toggle-bars span{display:block;height:2px;width:100%;background:currentColor;transition:transform 180ms var(--ease),opacity 140ms var(--ease)}
.site-header[data-open] .nav-toggle-bars span:nth-child(1){transform:translateY(6px) 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(-6px) rotate(-45deg)}

/* ============ footer ============ */
.site-footer{
  position:relative;overflow:hidden;
  background:var(--indigo);color:var(--paper);
  border-top:3px solid var(--cinnabar);
}
.site-footer::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    repeating-linear-gradient(90deg,rgba(255,249,238,.055) 0 1px,transparent 1px 88px),
    repeating-linear-gradient(0deg,rgba(255,249,238,.04) 0 1px,transparent 1px 88px);
}
.footer-inner{
  position:relative;
  width:min(calc(100% - var(--gutter) * 2),var(--shell));
  margin-inline:auto;
  padding-block:clamp(2.25rem,5vw,4rem) 0;
}
.footer-grid{
  display:grid;
  grid-template-columns:1.5fr .8fr .8fr 1.3fr;
  gap:clamp(1.5rem,3vw,3rem);
  padding-bottom:clamp(1.75rem,4vw,3rem);
}
.footer-brand{display:grid;gap:.55rem;align-content:start}
.footer-seal{
  display:grid;place-items:center;
  width:38px;height:38px;margin-bottom:.35rem;
  color:var(--sand);
  font-family:var(--font-serif);font-weight:700;font-size:1.1rem;line-height:1;
  border-radius:2px;
  box-shadow:inset 0 0 0 1px rgba(243,230,208,.6);
}
.footer-brandline{
  font-family:var(--font-serif);font-weight:800;
  font-size:clamp(1.05rem,1.6vw,1.3rem);
  letter-spacing:.04em;color:var(--paper);
}
.footer-lead{font-size:.92rem;color:rgba(255,249,238,.72);max-width:26ch}
.footer-domain{
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;
  color:var(--azurite-soft);
}
.footer-title{
  font-family:var(--font-mono);font-size:.7rem;font-weight:500;
  letter-spacing:.3em;color:var(--sand);
  padding-bottom:.6rem;margin-bottom:.85rem;
  border-bottom:1px solid var(--line-paper);
}
.footer-list li + li{margin-top:.5rem}
.footer-link{
  display:inline-block;
  font-size:.92rem;color:rgba(255,249,238,.76);
  border-bottom:1px solid transparent;
  transition:color 160ms var(--ease),border-color 160ms var(--ease),transform 160ms var(--ease);
}
.footer-link:hover,.footer-link[aria-current="page"]{color:var(--paper);border-bottom-color:rgba(243,230,208,.6);transform:translateX(2px)}
.footer-contact{display:grid;gap:.85rem;align-content:start}
.footer-address{display:grid;gap:.4rem}
.footer-mono{
  font-family:var(--font-mono);font-size:.82rem;letter-spacing:.01em;
  color:rgba(255,249,238,.86);word-break:break-word;line-height:1.55;
}
.footer-note{
  font-size:.8rem;line-height:1.7;color:rgba(255,249,238,.6);
  padding-left:.7rem;border-left:2px solid var(--cinnabar);
}
.footer-bottom{
  display:flex;flex-wrap:wrap;gap:.6rem 1.5rem;
  justify-content:space-between;align-items:center;
  padding-block:1.1rem;
  border-top:1px solid var(--line-paper);
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.08em;
  color:rgba(255,249,238,.6);
}
.footer-copy,.footer-legal{margin:0}

/* ============ shared layout ============ */
.container{width:min(calc(100% - var(--gutter) * 2),var(--shell));margin-inline:auto}
.container--wide{width:min(calc(100% - var(--gutter) * 2),1440px);margin-inline:auto}

.page-head{
  padding-block:clamp(1.75rem,4.5vw,3.25rem) clamp(1.5rem,3vw,2.5rem);
  border-bottom:1px solid var(--line-strong);
}
.page-title{max-width:22ch}
.page-lede{
  margin-top:1.1rem;max-width:58ch;
  font-size:1.02rem;color:var(--slate);
}

.crumb{padding-block:.95rem;border-bottom:1px solid var(--line);background:rgba(255,249,238,.45)}
.crumb-list{
  display:flex;flex-wrap:wrap;align-items:center;gap:.45rem;
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.08em;color:var(--slate);
}
.crumb-item{display:inline-flex;align-items:center;gap:.45rem}
.crumb-item + .crumb-item::before{content:"/";color:var(--ochre)}
.crumb-item a{transition:color 150ms var(--ease),border-color 150ms var(--ease);border-bottom:1px solid transparent}
.crumb-item a:hover{color:var(--azurite);border-bottom-color:var(--azurite)}
.crumb-item[aria-current="page"]{color:var(--ink)}

.section{position:relative;padding-block:clamp(2.25rem,5.5vw,4.5rem)}
.section--paper{background:var(--paper);border-block:1px solid var(--line)}
.section--jade{background:rgba(62,107,79,.09);border-block:1px solid rgba(62,107,79,.26)}
.section--deep{background:var(--indigo);color:var(--paper)}
.section--deep .section-title,.section--deep h2,.section--deep h3{color:var(--paper)}
.section--deep .eyebrow{color:var(--sand)}
.section--deep .section-note,.section--deep .card-text{color:rgba(255,249,238,.72)}

.section-head{display:grid;gap:.85rem;max-width:62ch;margin-bottom:clamp(1.5rem,3.5vw,2.5rem)}
.eyebrow{
  display:inline-flex;align-items:center;gap:.6rem;
  font-family:var(--font-mono);font-size:.7rem;letter-spacing:.28em;
  color:var(--ochre);text-transform:uppercase;
}
.eyebrow::before{content:"";width:1.9rem;height:1px;background:currentColor;opacity:.75}
.section-title{font-size:clamp(1.5rem,2.6vw,2rem);line-height:1.26}
.section-note{font-size:.95rem;color:var(--slate);max-width:56ch}

.chapter{
  display:flex;align-items:baseline;gap:.85rem;
  padding-top:.8rem;border-top:1px solid var(--line-strong);
}
.chapter-num{font-family:var(--font-mono);font-size:.76rem;letter-spacing:.16em;color:var(--ochre)}
.chapter-title{font-family:var(--font-serif);font-size:1.05rem;font-weight:700;letter-spacing:.02em}

.grid{display:grid;gap:clamp(1rem,2.4vw,1.75rem)}
.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(0,5fr) minmax(0,7fr)}
.grid--aside{grid-template-columns:minmax(0,260px) minmax(0,1fr)}
.stack{display:grid;gap:clamp(.9rem,2vw,1.4rem)}
.cluster{display:flex;flex-wrap:wrap;align-items:center;gap:.6rem}

.rule{border:0;border-top:1px solid var(--line);margin-block:clamp(1.5rem,3vw,2.5rem)}

/* ============ components ============ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.45rem;
  min-height:44px;padding:.6rem 1.1rem;
  border:1px solid var(--line-strong);border-radius:2px;
  background:transparent;color:var(--ink);
  font-size:.9rem;font-weight:500;letter-spacing:.02em;
  transition:background-color 160ms var(--ease),border-color 160ms var(--ease),color 160ms var(--ease),transform 160ms var(--ease);
}
.btn:hover{transform:translateY(-1px)}
.btn--primary{background:var(--cinnabar);border-color:var(--cinnabar);color:var(--paper);font-weight:700}
.btn--primary:hover{background:var(--cinnabar-deep);border-color:var(--cinnabar-deep)}
.btn--ghost{background:transparent;border-color:var(--line-strong);color:var(--ink)}
.btn--ghost:hover{border-color:var(--azurite);color:var(--azurite);background:rgba(31,95,107,.07)}
.btn--azure{background:var(--azurite);border-color:var(--azurite);color:var(--paper)}
.btn--azure:hover{background:#1A505A;border-color:#1A505A}
.btn--sm{min-height:36px;padding:.4rem .8rem;font-size:.8rem}

.card{
  position:relative;
  padding:clamp(1rem,2.2vw,1.5rem);
  background:var(--paper);
  border:1px solid var(--line-strong);
  border-radius:var(--radius);
  transition:transform 180ms var(--ease),border-color 180ms var(--ease),box-shadow 180ms var(--ease);
}
.card--azure{border-left:3px solid var(--azurite);background:linear-gradient(180deg,rgba(31,95,107,.07),var(--paper) 42%)}
.card--jade{border-left:3px solid var(--malachite);background:linear-gradient(180deg,rgba(62,107,79,.08),var(--paper) 42%)}
.card--ochre{border-left:3px solid var(--ochre)}
.card-title{font-family:var(--font-serif);font-size:1.05rem;font-weight:700;line-height:1.42}
.card-text{margin-top:.5rem;font-size:.94rem;line-height:1.72;color:var(--slate)}
@media (hover:hover){
  .card:hover{transform:translateY(-2px);border-color:var(--azurite-soft);box-shadow:0 16px 30px -26px rgba(31,36,33,.9)}
}

.tag{
  display:inline-flex;align-items:center;gap:.3rem;
  padding:.18rem .55rem;
  border:1px solid var(--line-strong);border-radius:2px;
  background:var(--paper);color:var(--slate);
  font-family:var(--font-mono);font-size:.68rem;letter-spacing:.08em;
}
.tag--azure{color:var(--azurite);border-color:rgba(31,95,107,.4);background:rgba(31,95,107,.08)}
.tag--jade{color:var(--malachite);border-color:rgba(62,107,79,.4);background:rgba(62,107,79,.09)}

.seal{
  display:inline-grid;place-items:center;
  min-width:2.6rem;padding:.28rem .45rem;
  background:var(--cinnabar);color:var(--paper);
  font-family:var(--font-mono);font-size:.76rem;line-height:1.15;letter-spacing:.04em;
  border-radius:2px;
  box-shadow:inset 0 0 0 1px rgba(255,249,238,.45);
}
.seal--ghost{background:transparent;color:var(--cinnabar);box-shadow:inset 0 0 0 1px var(--cinnabar)}

.figure{
  position:relative;margin:0;
  background:var(--paper);
  border:1px solid var(--line-strong);
  border-radius:var(--radius);
  overflow:hidden;
}
.figure__media{
  position:relative;
  aspect-ratio:16/10;
  background-color:var(--sand);
  background-image:
    linear-gradient(145deg,rgba(31,95,107,.28),rgba(166,94,46,.2) 52%,rgba(196,58,43,.14)),
    repeating-linear-gradient(90deg,rgba(255,249,238,.4) 0 1px,transparent 1px 30px),
    repeating-linear-gradient(0deg,rgba(31,36,33,.08) 0 1px,transparent 1px 30px);
  overflow:hidden;
}
.figure__media img,.figure__media svg{width:100%;height:100%;object-fit:cover;position:relative;z-index:1}
.figure--wide .figure__media{aspect-ratio:21/9}
.figure--tall .figure__media{aspect-ratio:3/4}
.figure figcaption{
  padding:.6rem .85rem;
  border-top:1px solid var(--line);
  background:var(--paper);
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.05em;color:var(--slate);
}

.prose{max-width:68ch;font-size:1rem;line-height:1.8;color:var(--ink)}
.prose > * + *{margin-top:1.05em}
.prose h2{
  font-size:clamp(1.35rem,2.2vw,1.7rem);
  margin-top:2.1em;padding-top:.7rem;border-top:1px solid var(--line);
}
.prose h3{font-family:var(--font-serif);font-size:1.1rem;margin-top:1.7em}
.prose ul li{position:relative;padding-left:1.15rem}
.prose ul li + li{margin-top:.4rem}
.prose ul li::before{content:"";position:absolute;left:0;top:.78em;width:.5rem;height:1px;background:var(--ochre)}
.prose a{color:var(--azurite);border-bottom:1px solid rgba(31,95,107,.45);transition:background-color 150ms var(--ease)}
.prose a:hover{background:rgba(31,95,107,.09)}
.prose blockquote{border-left:3px solid var(--ochre);padding:.3rem 0 .3rem 1rem;color:var(--slate)}

.timeline{position:relative;padding-left:1.6rem}
.timeline::before{
  content:"";position:absolute;left:5px;top:.5rem;bottom:.5rem;width:1px;
  background:linear-gradient(180deg,var(--ochre),rgba(166,94,46,.12));
}
.timeline-item{position:relative;padding-block:.3rem 1.4rem}
.timeline-item::before{
  content:"";position:absolute;left:-1.6rem;top:.95rem;
  width:11px;height:11px;
  background:var(--paper);border:1px solid var(--ochre);border-radius:1px;
  transform:rotate(45deg);
}
.timeline-date{font-family:var(--font-mono);font-size:.76rem;letter-spacing:.1em;color:var(--ochre)}
.timeline-body{margin-top:.35rem}

.scroll-progress{position:fixed;top:0;left:0;right:0;height:3px;z-index:140;pointer-events:none}
.scroll-progress__bar{
  height:100%;width:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cinnabar),var(--ochre));
  opacity:.92;
  transition:transform 90ms linear;
}

html[data-reveal-ready] [data-reveal]{opacity:0;transform:translateY(12px);transition:opacity .48s var(--ease),transform .48s var(--ease)}
html[data-reveal-ready] [data-reveal].is-visible{opacity:1;transform:none}

/* ============ responsive ============ */
@media (max-width:1140px){
  .nav-cap{display:none}
  .cmd-actions .btn--ghost{display:none}
}
@media (max-width:1000px){
  .nav-idx{display:none}
  .nav-link{padding-inline:.5rem}
  .nav-link::after{left:.5rem;right:.5rem}
  .footer-grid{grid-template-columns:1fr 1fr;}
  .footer-brand{grid-column:1 / -1}
  .footer-contact{grid-column:1 / -1}
}
@media (max-width:900px){
  :root{--header-h:58px}
  .cmd-bar{flex-wrap:wrap;align-items:stretch}
  .brand{flex:1 1 auto;min-height:var(--header-h)}
  .cmd-actions{display:none}
  .nav-toggle{display:inline-flex}
  .site-nav{
    position:absolute;left:0;right:0;top:100%;
    flex-direction:column;align-items:stretch;gap:0;
    padding:.75rem var(--gutter) 1.1rem;
    background:var(--paper);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line-strong);
    box-shadow:0 22px 34px -26px rgba(31,36,33,.9);
    max-height:min(72vh,30rem);overflow-y:auto;
    opacity:0;visibility:hidden;transform:translateY(-8px);
    transition:opacity 180ms var(--ease),transform 180ms var(--ease),visibility 180ms linear;
  }
  .site-header[data-open] .site-nav{opacity:1;visibility:visible;transform:none}
  .nav-list{flex-direction:column;align-items:stretch;overflow:visible;gap:0}
  .nav-item + .nav-item{border-top:1px solid var(--line)}
  .nav-link{width:100%;padding:.85rem .25rem;font-size:1rem}
  .nav-link::after{left:.25rem;bottom:.5rem;width:2rem;right:auto}
  .nav-cta{display:flex;flex-wrap:wrap;gap:.6rem;margin-top:1rem;padding-top:1rem;border-top:1px solid var(--line-strong)}
  .nav-cta .btn{flex:1 1 9rem}
  .grid--2,.grid--3,.grid--split,.grid--aside{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:1fr}
  .footer-brand,.footer-contact{grid-column:auto}
  .footer-bottom{justify-content:flex-start}
}
@media (max-width:640px){
  body{font-size:1rem;line-height:1.75}
  .brand-tag{display:none}
  .brand-name{font-size:.98rem}
  .page-title{max-width:none}
  .figure--wide .figure__media{aspect-ratio:16/10}
  .footer-inner{padding-top:2rem}
}

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