/* ========== 01 · reset ========== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,figure,blockquote,ul,ol,dl,dd{margin:0}
ul,ol{padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit}
table{border-collapse:collapse;width:100%}
main{display:block}

/* ========== 02 · tokens ========== */
:root{
  --sand:#E8DDC8;
  --paper:#F7F2E8;
  --clay:#B44A32;
  --clay-deep:#7A2F22;
  --coordinate:#1F5F8B;
  --night:#0E2233;
  --neon:#6C4AB6;
  --cyan:#2FD4C4;
  --line:#9B8C78;
  --line-soft:rgba(155,140,120,.36);
  --orange:#E07A3F;
  --rail-w:276px;
  --font-sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC",system-ui,-apple-system,sans-serif;
  --font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
  --radius:4px;
  --shadow-card:0 1px 0 rgba(14,34,51,.05),0 14px 28px -22px rgba(14,34,51,.65);
  --ease:cubic-bezier(.2,.7,.3,1);
}

/* ========== 03 · base type ========== */
body{
  background:var(--paper);
  color:var(--night);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.8;
  letter-spacing:.012em;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
h1,h2,h3,h4,h5{
  font-weight:800;
  line-height:1.2;
  letter-spacing:.03em;
  color:var(--night);
  text-wrap:balance;
}
h1{font-size:clamp(2rem,5vw,3.6rem);letter-spacing:.04em}
h2{font-size:clamp(1.5rem,2.8vw,2.25rem)}
h3{font-size:clamp(1.125rem,1.7vw,1.375rem);letter-spacing:.02em}
h4{font-size:1rem;letter-spacing:.06em}
p{line-height:1.85}
a{color:var(--coordinate);text-decoration-thickness:1px;text-underline-offset:.18em;transition:color .16s var(--ease)}
a:hover{color:var(--clay)}
strong{font-weight:800}
small{font-size:.82em}
:focus-visible{outline:2px solid var(--neon);outline-offset:3px;border-radius:2px}

/* ========== 04 · header ========== */
.skip-link{
  position:absolute;left:12px;top:-120px;z-index:200;
  padding:10px 18px;border-radius:0 0 var(--radius) var(--radius);
  background:var(--night);color:var(--paper);font-size:13px;font-weight:700;letter-spacing:.08em;
  text-decoration:none;transition:top .18s var(--ease);
}
.skip-link:focus{top:0;color:#fff}

.site-header{
  position:sticky;top:0;z-index:60;
  background-color:var(--sand);
  background-image:repeating-linear-gradient(90deg,rgba(31,95,139,.10) 0 1px,transparent 1px 28px);
  border-bottom:1px solid var(--line-soft);
  color:var(--night);
}
.site-header.is-scrolled{box-shadow:0 14px 26px -24px rgba(14,34,51,.95)}
.scroll-progress{
  position:absolute;left:0;bottom:-1px;width:0;height:3px;
  background:linear-gradient(90deg,var(--clay),var(--orange),var(--neon));
  transition:width .12s linear;
}

.rail{display:flex;flex-wrap:wrap;align-items:center;gap:10px 12px;padding:11px 16px 12px}

.brand{flex:1 1 auto;display:inline-flex;align-items:center;gap:10px;min-width:0;text-decoration:none;color:inherit}
.brand:hover{color:inherit}
.brand__mark{
  flex:0 0 auto;width:36px;height:36px;display:grid;place-items:center;
  border-radius:3px;background:var(--clay);color:#fff;
  font-weight:800;font-size:16px;line-height:1;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.2),0 0 0 4px rgba(180,74,50,.12);
}
.brand__text{display:flex;flex-direction:column;min-width:0}
.brand__name{font-size:14.5px;font-weight:800;letter-spacing:.05em;line-height:1.3;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.brand__tagline{font-family:var(--font-mono);font-size:10px;letter-spacing:.1em;line-height:1.6;color:var(--clay-deep);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

.nav-toggle{
  flex:0 0 auto;display:inline-flex;align-items:center;gap:8px;
  padding:8px 14px;border-radius:999px;border:1px solid var(--night);
  background:transparent;color:var(--night);
  font-size:13px;font-weight:700;letter-spacing:.08em;cursor:pointer;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.nav-toggle:hover{background:var(--night);color:var(--sand)}
.nav-toggle__bars{position:relative;display:block;width:16px;height:12px}
.nav-toggle__bars span{position:absolute;left:0;width:16px;height:2px;border-radius:1px;background:currentColor;transition:transform .22s var(--ease),opacity .16s var(--ease)}
.nav-toggle__bars span:nth-child(1){top:0}
.nav-toggle__bars span:nth-child(2){top:5px}
.nav-toggle__bars span:nth-child(3){top:10px}
.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)}
.nav-toggle__label{display:block}

.rail__nav{
  order:3;flex:1 0 100%;display:none;
  margin-top:2px;padding-top:12px;border-top:1px dashed var(--line-soft);
}
.site-header[data-open] .rail__nav{display:block}
.rail__eyebrow{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.26em;text-transform:uppercase;
  color:var(--coordinate);margin-bottom:8px;
}
.nav-list{display:flex;flex-direction:column;gap:2px}
.nav-link{
  display:flex;align-items:baseline;gap:10px;
  padding:8px 11px;border-radius:3px;border-left:2px solid transparent;
  color:var(--night);font-size:15px;font-weight:600;letter-spacing:.03em;
  text-decoration:none;
  transition:background .16s var(--ease),color .16s var(--ease),border-color .16s var(--ease);
}
.nav-link__num{min-width:1.9em;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.1em;color:var(--coordinate);opacity:.9}
.nav-link__label{flex:1 1 auto}
.nav-link:hover{background:rgba(31,95,139,.12);color:var(--clay-deep)}
.nav-link[aria-current="page"]{background:var(--clay);color:#fff;border-left-color:var(--cyan)}
.nav-link[aria-current="page"] .nav-link__num{color:#FFD9C6;opacity:1}
.nav-link[aria-current="page"]:hover{background:var(--clay-deep);color:#fff}

.rail__foot{display:none}
.rail__note{font-family:var(--font-mono);font-size:10px;letter-spacing:.16em;color:#8FB6CE;line-height:1.6}
.rail__cta{
  margin-top:10px;display:inline-flex;align-items:center;justify-content:space-between;gap:8px;
  width:100%;padding:9px 12px;border-radius:3px;border:1px solid rgba(47,212,196,.5);
  color:var(--cyan);font-size:12.5px;font-weight:700;letter-spacing:.1em;text-decoration:none;
  transition:background .18s var(--ease),color .18s var(--ease);
}
.rail__cta::after{content:"→";font-family:var(--font-mono)}
.rail__cta:hover{background:var(--cyan);color:var(--night)}

/* ========== 05 · footer ========== */
.site-footer{
  position:relative;background:var(--night);color:#DCD3C1;
  border-top:3px solid var(--clay);
  overflow:hidden;
}
.site-footer::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    repeating-linear-gradient(90deg,rgba(47,212,196,.07) 0 1px,transparent 1px 34px),
    repeating-linear-gradient(0deg,rgba(47,212,196,.05) 0 1px,transparent 1px 34px);
}
.site-footer::after{
  content:"";position:absolute;right:-80px;top:-80px;width:280px;height:280px;pointer-events:none;
  border:1px solid rgba(108,74,182,.5);border-radius:50%;
  box-shadow:0 0 0 34px rgba(108,74,182,.08);
}
.footer__inner{position:relative;z-index:1;max-width:1180px;margin:0 auto;padding:44px 20px 26px}
.footer__grid{display:grid;grid-template-columns:1fr;gap:30px}
.footer__col{display:flex;flex-direction:column;min-width:0}
.footer__col--brand{gap:0}
.footer__wordmark{
  margin-top:12px;font-size:clamp(1.45rem,3vw,2rem);font-weight:800;
  letter-spacing:.06em;line-height:1.2;color:var(--paper);
}
.footer__wordmark-sub{display:inline-block;margin-left:6px;font-size:.6em;font-weight:700;letter-spacing:.16em;color:var(--clay);vertical-align:baseline}
.footer__summary{margin-top:12px;max-width:34ch;font-size:14px;line-height:1.85;color:#BFB4A0}
.footer__coord{margin-top:14px;font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--cyan);opacity:.85}
.footer__heading{
  display:block;margin-bottom:14px;padding-bottom:10px;
  border-bottom:1px solid rgba(247,242,232,.16);
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.22em;text-transform:uppercase;color:var(--paper);
}
.footer__list{display:flex;flex-direction:column;gap:9px}
.footer__list--plain{gap:13px}
.footer__list--plain li{display:flex;flex-direction:column;gap:2px}
.footer__k{font-family:var(--font-mono);font-size:9.5px;letter-spacing:.2em;text-transform:uppercase;color:rgba(47,212,196,.8)}
.footer__link{
  display:inline-block;font-size:14px;color:#D6CCB9;text-decoration:none;
  transition:color .16s var(--ease),padding-left .16s var(--ease);
}
.footer__link:hover{color:var(--cyan);padding-left:5px}
.footer__contact{font-size:13.5px;line-height:1.7;color:#D6CCB9;word-break:break-word}
.footer__col .eyebrow{color:rgba(47,212,196,.82)}
.footer__bottom{
  display:flex;flex-direction:column;gap:8px;
  margin-top:34px;padding-top:18px;border-top:1px solid rgba(247,242,232,.16);
}
.footer__legal{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.08em;color:#B5A991}
.footer__icp{color:#C9BEA8}
.footer__note{font-size:11.5px;line-height:1.7;color:#8B7F6C;max-width:58ch}

/* ========== 06 · shared layout ========== */
.container{width:100%;max-width:1180px;margin:0 auto;padding:0 20px}
.container--narrow{max-width:780px}
.section{padding:52px 0}
.section--sand{background:var(--sand)}
.section--night{background:var(--night);color:var(--paper)}
.section--night h1,.section--night h2,.section--night h3{color:var(--paper)}
.section__head{display:flex;flex-wrap:wrap;align-items:baseline;gap:10px 18px;margin-bottom:26px}
.section__title{font-size:clamp(1.5rem,2.8vw,2.25rem)}
.section__lead{max-width:56ch;font-size:15.5px;color:var(--clay-deep);line-height:1.85}
.section--night .section__lead{color:#BFB4A0}

.grid{display:grid;gap:20px;grid-template-columns:1fr}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.22em;text-transform:uppercase;
  color:var(--coordinate);
}
.eyebrow::before{content:"";display:inline-block;width:22px;height:1px;background:currentColor;opacity:.75}

.prose{max-width:68ch;font-size:16.5px;line-height:1.9}
.prose p+p{margin-top:1.1em}
.prose h2{margin:1.7em 0 .6em}
.prose h3{margin:1.4em 0 .5em}
.prose ul{list-style:disc;padding-left:1.25em;margin:1em 0}
.prose li{margin:.35em 0;line-height:1.8}

/* ========== 07 · components ========== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 22px;border-radius:2px;border:1px solid transparent;
  font-size:15px;font-weight:700;letter-spacing:.05em;text-decoration:none;cursor:pointer;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease);
}
.btn--solid{background:var(--clay);border-color:var(--clay);color:#fff}
.btn--solid:hover{background:var(--clay-deep);border-color:var(--clay-deep);color:#fff;transform:translateY(-2px)}
.btn--ghost{background:transparent;border-color:var(--night);color:var(--night)}
.btn--ghost:hover{background:var(--night);color:var(--sand);transform:translateY(-2px)}
.btn--blue{background:var(--coordinate);border-color:var(--coordinate);color:#fff}
.btn--blue:hover{background:#17496a;border-color:#17496a;color:#fff;transform:translateY(-2px)}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:999px;border:1px solid currentColor;
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.14em;line-height:1.6;
  color:var(--coordinate);background:rgba(31,95,139,.07);
}
.tag--clay{color:var(--clay);background:rgba(180,74,50,.09)}
.tag--neon{color:var(--neon);background:rgba(108,74,182,.11)}

.card{
  padding:20px;border:1px solid var(--line-soft);border-radius:var(--radius);
  background:var(--paper);box-shadow:var(--shadow-card);
}
.card--sand{background:var(--sand)}

.breadcrumbs{padding:16px 0 0;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.12em;color:var(--clay-deep)}
.breadcrumbs ol{display:flex;flex-wrap:wrap;align-items:center;gap:6px}
.breadcrumbs li{display:inline-flex;align-items:center;gap:6px}
.breadcrumbs li::after{content:"/";color:var(--line)}
.breadcrumbs li:last-child::after{content:""}
.breadcrumbs a{color:var(--coordinate);text-decoration:none}
.breadcrumbs a:hover{color:var(--clay)}

.figure{display:block}
.figure__media{
  position:relative;overflow:hidden;border-radius:var(--radius);
  border:1px solid var(--line-soft);background:var(--sand);
}
.figure__media>img{width:100%;height:100%;object-fit:cover}
.figure__media::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:repeating-linear-gradient(0deg,rgba(14,34,51,.14) 0 1px,transparent 1px 5px);
  mix-blend-mode:multiply;opacity:.45;
}
.figure--wide .figure__media{aspect-ratio:16/9}
.figure--tall .figure__media{aspect-ratio:3/4}
.figure--square .figure__media{aspect-ratio:1/1}
.figure__caption{
  display:flex;flex-wrap:wrap;gap:8px;align-items:baseline;
  margin-top:9px;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.1em;color:var(--clay-deep);
}

.filter-bar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:2px 0}
.filter-chip{
  padding:7px 15px;border-radius:999px;border:1px solid var(--line);
  background:transparent;color:var(--night);cursor:pointer;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.12em;
  transition:background .16s var(--ease),color .16s var(--ease),border-color .16s var(--ease);
}
.filter-chip:hover{border-color:var(--clay);color:var(--clay)}
.filter-chip[aria-pressed="true"]{background:var(--night);border-color:var(--night);color:var(--sand)}
.filter-item{min-width:0}
.filter-item.is-hidden{display:none}

.js .reveal{opacity:0;transform:translateY(14px);transition:opacity .6s var(--ease),transform .6s var(--ease)}
.js .reveal.is-visible{opacity:1;transform:none}

/* ========== 08 · tablet ========== */
@media (min-width:640px){
  .rail{padding:12px 24px 13px}
  .brand__name{font-size:16px}
  .brand__tagline{font-size:10.5px}
  .footer__inner{padding:52px 24px 28px}
  .footer__grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:34px}
  .footer__col--brand{grid-column:1 / -1}
  .section{padding:64px 0}
}
@media (min-width:760px){
  .container{padding:0 32px}
  .grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
  .grid--4{grid-template-columns:repeat(2,minmax(0,1fr))}
}

/* ========== 09 · desktop rail ========== */
@media (min-width:1000px){
  body{padding-left:var(--rail-w)}
  .site-header{
    position:fixed;inset:0 auto 0 0;width:var(--rail-w);
    border-bottom:0;border-right:1px solid rgba(47,212,196,.24);
    background-color:var(--night);
    background-image:
      repeating-linear-gradient(0deg,rgba(47,212,196,.075) 0 1px,transparent 1px 30px),
      repeating-linear-gradient(90deg,rgba(47,212,196,.05) 0 1px,transparent 1px 30px);
    color:var(--paper);overflow:hidden;
  }
  .site-header.is-scrolled{box-shadow:8px 0 26px -22px rgba(14,34,51,.95)}
  .rail{
    flex-wrap:nowrap;flex-direction:column;align-items:stretch;
    height:100%;padding:26px 22px 20px;gap:0;
  }
  .brand{flex:0 0 auto}
  .brand__name{color:#F7F2E8;font-size:15px}
  .brand__tagline{color:#8FB6CE}
  .brand__mark{box-shadow:inset 0 0 0 1px rgba(255,255,255,.18),0 0 0 4px rgba(47,212,196,.14)}
  .nav-toggle{display:none}
  .rail__nav{
    order:0;display:block;flex:1 1 auto;overflow-y:auto;
    margin-top:24px;padding-top:18px;border-top:1px solid rgba(247,242,232,.18);
  }
  .rail__eyebrow{color:rgba(47,212,196,.85)}
  .nav-link{color:#E4DCCB}
  .nav-link__num{color:rgba(47,212,196,.85)}
  .nav-link:hover{background:rgba(247,242,232,.09);color:#fff}
  .nav-link[aria-current="page"]{background:var(--clay);color:#fff;border-left-color:var(--cyan)}
  .nav-link[aria-current="page"]:hover{background:var(--clay-deep);color:#fff}
  .rail__foot{display:block;flex:0 0 auto;margin-top:18px;padding-top:16px;border-top:1px solid rgba(247,242,232,.18)}
  .scroll-progress{
    left:auto;right:0;top:0;bottom:auto;width:3px;height:0;
    background:linear-gradient(180deg,var(--cyan),var(--neon));
    transition:height .12s linear;
  }
  .container{padding:0 48px}
  .section{padding:88px 0}
  .grid{gap:24px}
  .grid--12{grid-template-columns:repeat(12,minmax(0,1fr))}
  .grid--4{grid-template-columns:repeat(4,minmax(0,1fr))}
  .footer__inner{padding:64px 48px 32px}
  .footer__grid{grid-template-columns:1.6fr 1fr 1fr 1.25fr;gap:40px}
  .footer__col--brand{grid-column:auto}
  .footer__bottom{flex-direction:row;align-items:center;justify-content:space-between;gap:24px;margin-top:38px}
}

/* ========== 10 · motion preferences ========== */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important}
  .js .reveal{opacity:1;transform:none}
  .btn:hover,.filter-chip:hover,.footer__link:hover{transform:none;padding-left:0}
}