@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@300;400;500;600;700&family=Noto+Sans:wght@300;400;500;600;700&display=swap');

:root{
  --ink:#000000;
  --paper:#ffffff;
  --line:rgba(0,0,0,.18);
  --line-soft:rgba(0,0,0,.08);
  --glass:rgba(255,255,255,.82);
  --rail:264px;
  --font:"Be Vietnam Pro","Noto Sans",system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif;
}

*,*::before,*::after{box-sizing:border-box}

html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;overflow-x:hidden;max-width:100%}

body{
  margin:0;
  font-family:var(--font);
  font-size:18px;
  line-height:1.72;
  color:var(--ink);
  background:radial-gradient(rgba(0,0,0,.14) 1px,transparent 1px) 0 0/18px 18px,var(--paper);
  overflow-x:hidden;
  max-width:100%;
  -webkit-font-smoothing:antialiased;
}

/* 容器内元素一律允许收缩，避免撑破视口 */
.frame>*,.cols>*,.hero>*,.hero-copy>*,.foot>*,.foot-block>*,.prose>*,.prose>article>*,.side>*{min-width:0}

h1,h2,h3,h4{margin:0;font-weight:600;line-height:1.22;letter-spacing:-.01em}
p{margin:0}
a{color:inherit;text-decoration:none}
ul,ol{margin:0;padding:0}
img{display:block;max-width:100%;height:auto}
iframe,video,svg{max-width:100%}
:focus-visible{outline:2px solid var(--ink);outline-offset:3px}

article[id]{scroll-margin-top:28px}

.skip{position:absolute;left:-9999px;top:0;z-index:90;background:var(--ink);color:var(--paper);padding:12px 18px;font-size:16px}
.skip:focus{left:12px;top:12px}

.strip{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:11px 20px;border-bottom:1px solid var(--ink);background:var(--paper);
  font-size:15px;letter-spacing:.2em;line-height:1.3;min-width:0;
}
.strip-brand{font-weight:600;flex:none}
.strip-kw{color:rgba(0,0,0,.55);min-width:0;overflow-wrap:anywhere}

.frame{display:grid;grid-template-columns:var(--rail) minmax(0,1fr);align-items:start;min-width:0}

.rail{
  position:sticky;top:0;z-index:6;height:100vh;
  display:flex;flex-direction:column;gap:26px;
  padding:24px 20px;border-right:1px solid var(--line);background:var(--paper);
  min-width:0;
}

.brand{display:inline-flex;align-items:center;gap:10px;min-height:44px;font-size:21px;font-weight:700;letter-spacing:.02em;min-width:0}
.brand .mark{width:14px;height:14px;background:var(--ink);border-radius:3px;flex:none}
.brand img.mark{background:none;border-radius:0;object-fit:contain}
.brand span{line-height:1.15;min-width:0;overflow-wrap:anywhere}

.nav{min-width:0;max-width:100%}
.nav ol{list-style:none;counter-reset:n;display:flex;flex-direction:column;gap:1px;min-width:0}
.nav li{counter-increment:n;min-width:0}
.nav a{
  display:flex;align-items:center;gap:10px;min-height:44px;padding:6px;
  font-size:16px;border-top:1px solid var(--line-soft);
  transition:background .18s ease,color .18s ease;
}
.nav a::before{
  content:counter(n,decimal-leading-zero);
  font-size:13px;letter-spacing:.06em;opacity:.5;min-width:2.2ch;font-variant-numeric:tabular-nums;
}
.nav .ic{width:12px;height:12px;flex:none;opacity:.75}
.nav .t{min-width:0;overflow-wrap:anywhere}
.nav a:hover,.nav a:focus-visible{background:var(--ink);color:var(--paper)}
.nav a:hover::before,.nav a:focus-visible::before{opacity:.8}

.hero{
  display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:16px;align-items:center;
  min-height:70vh;padding:64px 40px;border-bottom:1px solid var(--line);min-width:0;
}
.hero-copy{grid-column:4 / 11;text-align:right;border-right:1px solid var(--line);padding-right:32px;min-width:0}
.hero-copy h1{font-size:clamp(30px,4.2vw,54px);font-weight:700;letter-spacing:-.02em;line-height:1.14;margin-bottom:.5em;overflow-wrap:anywhere}
.lede{font-size:17px;line-height:1.7;color:rgba(0,0,0,.72);max-width:44ch;margin-left:auto;overflow-wrap:anywhere}
.hero-fig{grid-column:11 / 13;margin:0;overflow:hidden;border:1px solid var(--line);border-radius:18px;background:var(--glass);backdrop-filter:blur(8px);max-width:100%}
.fig-art{display:block;width:100%;height:auto;transform:translateY(var(--py,0));transition:transform .1s linear}

.cols{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:16px;padding:40px;align-items:start;min-width:0}

.prose{grid-column:1 / 9;min-width:0;overflow-wrap:anywhere;max-width:100%}
.prose > article{
  margin-bottom:16px;padding:28px 30px 30px;
  background:var(--glass);backdrop-filter:blur(10px);
  border:1px solid var(--line);border-radius:18px;
  min-width:0;max-width:100%;
}
.prose > article:last-child{margin-bottom:0}
.prose h2{font-size:clamp(22px,2.4vw,30px);margin-bottom:.65em;overflow-wrap:anywhere}
.prose h3{font-size:20px;margin:1.4em 0 .5em;overflow-wrap:anywhere}
.prose p{margin-bottom:1em;max-width:66ch}
.prose ul,.prose ol{padding-left:1.35em;margin-bottom:1em}
.prose li{margin-bottom:.4em}
.prose li::marker{color:rgba(0,0,0,.5)}
.prose a{border-bottom:1px solid var(--ink);overflow-wrap:anywhere}
.prose strong{font-weight:700}
.prose blockquote{margin:1.2em 0;padding:2px 0 2px 18px;border-left:2px solid var(--ink);color:rgba(0,0,0,.75)}
.prose img{margin:1.2em 0;border:1px solid var(--line);border-radius:18px;max-width:100%}
.prose figure{margin:1.2em 0;max-width:100%}
.prose figcaption{font-size:15px;color:rgba(0,0,0,.6);margin-top:.5em}
.prose table{
  display:block;width:100%;max-width:100%;overflow-x:auto;
  border-collapse:collapse;font-size:16px;margin-bottom:1.2em;
  -webkit-overflow-scrolling:touch;
}
.prose th,.prose td{border:1px solid var(--line);padding:10px 12px;text-align:left}
.prose th{background:rgba(0,0,0,.04)}
.prose code{font-size:15px;background:rgba(0,0,0,.06);padding:2px 5px;border-radius:4px;overflow-wrap:anywhere}
.prose pre{overflow-x:auto;max-width:100%;background:var(--ink);color:var(--paper);padding:16px;border-radius:18px;-webkit-overflow-scrolling:touch}
.prose pre code{background:none;padding:0;overflow-wrap:normal}
.prose hr{border:0;border-top:1px solid var(--line);margin:1.6em 0}

.side{
  grid-column:9 / 13;position:sticky;top:24px;min-width:0;
  padding:22px 22px 24px;background:var(--glass);backdrop-filter:blur(10px);
  border:1px solid var(--line);border-radius:18px;
}
.eyebrow{display:block;font-size:15px;letter-spacing:.2em;color:rgba(0,0,0,.55);margin-bottom:6px}
.side-h{font-size:22px;margin-bottom:14px}
.side-list{list-style:none;counter-reset:s}
.side-list li{counter-increment:s;border-top:1px solid var(--line-soft)}
.side-list a{display:flex;align-items:center;gap:10px;min-height:42px;padding:4px 0;font-size:16px;overflow-wrap:anywhere}
.side-list a::before{content:counter(s,decimal-leading-zero);font-size:13px;opacity:.5;font-variant-numeric:tabular-nums;flex:none}
.side-list a:hover{text-decoration:underline;text-underline-offset:3px}

.foot{border-top:1px solid var(--ink);background:var(--paper);padding:56px 40px 24px;display:grid;gap:36px;min-width:0}
.cta{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:20px;padding-bottom:32px;border-bottom:1px solid var(--line);min-width:0}
.cta-text{font-size:clamp(30px,7vw,64px);font-weight:700;letter-spacing:-.03em;line-height:1;overflow-wrap:anywhere}
.cta-btn{
  display:inline-flex;align-items:center;min-height:48px;padding:12px 30px;
  border:1px solid var(--ink);border-radius:999px;font-size:16px;letter-spacing:.06em;
  transition:background .18s ease,color .18s ease;
}
.cta-btn:hover{background:var(--ink);color:var(--paper)}
.foot-block{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:16px;min-width:0}
.foot address{
  grid-column:1 / 6;display:flex;flex-direction:column;gap:4px;min-width:0;
  font-style:normal;font-size:16px;line-height:1.6;color:rgba(0,0,0,.75);
  overflow-wrap:anywhere;
}
.foot address span:first-child{color:var(--ink);font-weight:600}
.foot-links{grid-column:8 / 13;list-style:none;display:flex;flex-wrap:wrap;gap:4px 18px;justify-content:flex-end;min-width:0}
.foot-links a{display:inline-flex;align-items:center;min-height:40px;font-size:16px;border-bottom:1px solid transparent;overflow-wrap:anywhere}
.foot-links a:hover{border-bottom-color:var(--ink)}
.copy{text-align:center;font-size:15px;letter-spacing:.16em;color:rgba(0,0,0,.6);border-top:1px solid var(--line-soft);padding-top:18px;overflow-wrap:anywhere}

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

@media (max-width:1080px){
  .hero-copy{grid-column:3 / 10}
  .hero-fig{grid-column:10 / 13}
  .prose{grid-column:1 / 10}
  .side{grid-column:10 / 13}
}

@media (max-width:860px){
  .frame{grid-template-columns:1fr}
  .rail{position:static;height:auto;gap:14px;padding:14px 16px;border-right:0;border-bottom:1px solid var(--line);overflow:hidden}
  .nav{width:100%;max-width:100%}
  .nav ol{
    flex-direction:row;gap:8px;overflow-x:auto;padding-bottom:6px;
    -webkit-overflow-scrolling:touch;scrollbar-width:thin;
  }
  .nav li{flex:none}
  .nav a{
    min-height:44px;padding:9px 14px;font-size:16px;white-space:nowrap;
    border:1px solid var(--line);border-radius:999px;
  }
  .nav a::before{min-width:auto;font-size:12px}
  .hero{grid-template-columns:1fr;min-height:0;padding:28px 16px 32px;gap:22px}
  .hero-copy,.hero-fig{grid-column:1 / -1}
  .hero-copy{text-align:left;border-right:0;padding-right:0}
  .lede{margin-left:0;max-width:none}
  .hero-fig{max-width:min(320px,100%)}
  .cols{grid-template-columns:1fr;padding:20px 16px 32px}
  .prose,.side{grid-column:1 / -1}
  .side{position:static;margin-top:16px}
  .prose > article{padding:22px 18px 24px}
  .prose table{font-size:15px}
  .foot{padding:36px 16px 20px;gap:26px}
  .foot-block{grid-template-columns:1fr}
  .foot address,.foot-links{grid-column:1 / -1}
  .foot-links{justify-content:flex-start}
}

@media (max-width:420px){
  .strip{padding:10px 14px;letter-spacing:.14em}
  .prose{font-size:17px}
  .prose > article{padding:20px 15px 22px}
  .cta-btn{padding:12px 24px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js .reveal{opacity:1;transform:none;transition:none}
  .fig-art{transition:none}
}

button[aria-expanded]{min-width:44px;min-height:44px}