:root{
  --ink:#0E1116;
  --amber:#FFC53D;
  --paper:#ECEFF4;
  --muted:#9AA4B2;
  --body:#C4CBD7;
  --line:rgba(236,239,244,.16);
  --rail:236px;
  --max:1180px;
}

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

html{
  scroll-behavior:smooth;
  -webkit-text-size-adjust:100%;
}

body{
  margin:0;
  padding-left:var(--rail);
  background-color:var(--ink);
  background-image:radial-gradient(rgba(236,239,244,.08) 1px,transparent 1px);
  background-size:26px 26px;
  color:var(--paper);
  font-family:'Inter',system-ui,-apple-system,'Noto Sans SC','PingFang SC','Microsoft YaHei',sans-serif;
  font-size:17px;
  font-weight:400;
  line-height:1.65;
  letter-spacing:.005em;
}

a{color:var(--amber);text-decoration:none}
img{display:block;max-width:100%;height:auto}
p{margin:0 0 1.05em}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

/* ---------- 左侧固定栏 ---------- */
.rail{
  position:fixed;
  inset:0 auto 0 0;
  width:var(--rail);
  display:flex;
  flex-direction:column;
  background:#0A0D12;
  border-right:2px solid var(--line);
  z-index:20;
}

.strip{
  margin:0;
  padding:9px 16px;
  background:var(--amber);
  color:var(--ink);
  font-size:11px;
  font-weight:700;
  letter-spacing:.26em;
  line-height:1.4;
}

.rail-brand{
  display:grid;
  place-items:center;
  width:50px;
  height:50px;
  margin:20px 16px 6px;
  border:2px solid var(--amber);
  color:var(--amber);
  transition:background-color .18s ease,color .18s ease;
}
.rail-brand:hover{background:var(--amber);color:var(--ink)}

.rail-nav{padding:10px 12px 24px}
.rail-nav p{
  display:flex;
  flex-wrap:wrap;
  gap:6px;
  margin:0;
}
.rail-nav a{
  display:inline-block;
  padding:10px 12px;
  border:2px solid var(--line);
  color:var(--paper);
  font-size:16px;
  font-weight:500;
  line-height:1.2;
  transition:background-color .16s ease,color .16s ease,border-color .16s ease;
}
.rail-nav a:hover{background:var(--amber);border-color:var(--amber);color:var(--ink)}
.rail-nav a[aria-current]{
  background:var(--amber);
  border-color:var(--amber);
  color:var(--ink);
}

/* ---------- 主栅格 ---------- */
.layout{
  display:grid;
  grid-template-columns:minmax(0,1fr) 288px;
  align-items:start;
  gap:clamp(24px,4vw,60px);
  max-width:var(--max);
  margin:0 auto;
  padding:clamp(28px,5vw,68px) clamp(20px,4vw,48px);
}

main{min-width:0}
section{max-width:72ch}

/* ---------- 首屏 ---------- */
.hero{
  display:grid;
  place-items:center;
  min-height:100vh;
  padding:clamp(32px,6vw,72px) 0;
  border-bottom:2px solid var(--line);
  background-image:radial-gradient(rgba(255,197,61,.20) 1.4px,transparent 1.4px);
  background-size:22px 22px;
}

.hero-inner{
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,1fr);
  align-items:center;
  gap:clamp(24px,4vw,56px);
  width:100%;
}
.hero-inner.solo{grid-template-columns:minmax(0,1fr)}
.hero-inner.solo .hero-txt{max-width:56ch;margin:0 auto}

.hero-fig{
  margin:0;
  overflow:hidden;
  border:2px solid var(--amber);
  aspect-ratio:4 / 3;
  background:#131820;
}
.hero-fig img{
  width:100%;
  height:100%;
  object-fit:cover;
  transform:scale(1.18);
  transform-origin:center;
}

.hero-txt{text-align:center}

.eyebrow{
  display:block;
  color:var(--amber);
  font-size:12px;
  font-weight:600;
  letter-spacing:.26em;
  line-height:1.6;
}

h1{
  margin:.18em 0 .38em;
  font-size:clamp(2rem,5.2vw,3.6rem);
  font-weight:700;
  line-height:1.08;
  letter-spacing:-.02em;
}

.hero-lede{
  max-width:36ch;
  margin:0 auto 28px;
  color:var(--body);
  font-size:clamp(1rem,1.5vw,1.1rem);
}

.btn{
  display:inline-block;
  padding:13px 26px;
  border:2px solid var(--amber);
  background:var(--amber);
  color:var(--ink);
  font-size:16px;
  font-weight:700;
  letter-spacing:.08em;
  line-height:1.25;
  transition:background-color .18s ease,color .18s ease,border-color .18s ease;
}
.btn:hover{background:transparent;color:var(--amber)}

.btn-ghost{
  display:block;
  text-align:center;
  background:transparent;
  border-color:var(--line);
  color:var(--paper);
  letter-spacing:.06em;
}
.btn-ghost:hover{border-color:var(--amber);color:var(--amber);background:transparent}

/* ---------- 正文区块 ---------- */
section > div:not(.hero){
  padding:clamp(28px,4vw,46px) 0;
  border-top:2px solid var(--line);
  scroll-margin-top:18px;
}
.hero + div{border-top:0;padding-top:clamp(30px,4vw,48px)}

div h2{
  margin:.3em 0 .62em;
  font-size:clamp(1.45rem,2.6vw,2.05rem);
  font-weight:700;
  line-height:1.2;
  letter-spacing:-.012em;
}
div h3{
  margin:1.5em 0 .5em;
  font-size:clamp(1.15rem,1.9vw,1.35rem);
  font-weight:600;
  line-height:1.3;
}
div h2 + h3{margin-top:.4em}
div p{color:var(--body);max-width:66ch}
div strong{color:var(--paper);font-weight:600}
div a{text-decoration:underline;text-underline-offset:3px}

div ul,div ol{max-width:66ch;margin:0 0 1.25em;padding:0;list-style:none;display:grid;gap:10px}
div ol{counter-reset:li}
div ul > li{position:relative;padding-left:22px;color:var(--body)}
div ul > li::before{
  content:"";
  position:absolute;left:0;top:.6em;
  width:8px;height:8px;background:var(--amber);
}
div ol > li{position:relative;padding-left:30px;color:var(--body);counter-increment:li}
div ol > li::before{
  content:counter(li);
  position:absolute;left:0;top:.15em;
  color:var(--amber);font-weight:700;font-size:14px;
  border:2px solid var(--amber);width:22px;height:22px;
  display:grid;place-items:center;line-height:1;
}

div blockquote{
  margin:1.4em 0;
  padding:14px 20px;
  border-left:4px solid var(--amber);
  background:rgba(255,197,61,.07);
  color:var(--body);
}
div blockquote p:last-child{margin-bottom:0}

div img{margin:1.3em 0;border:2px solid var(--line)}
div figure{margin:1.3em 0}
div figcaption{color:var(--muted);font-size:15px;padding-top:6px}

div table{width:100%;border-collapse:collapse;margin:0 0 1.3em;font-size:16px}
div th,div td{border:2px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
div th{background:rgba(255,197,61,.1);color:var(--paper);font-weight:600}
div td{color:var(--body)}
div hr{border:0;border-top:2px solid var(--line);margin:1.8em 0}

/* ---------- 右侧边栏 ---------- */
.side{
  position:sticky;
  top:24px;
  padding-left:20px;
  border-left:2px solid var(--amber);
}
.side h3{
  margin:.32em 0 .9em;
  font-size:1.3rem;
  font-weight:700;
  letter-spacing:-.01em;
}
.toc{list-style:none;margin:0 0 22px;padding:0}
.toc li a{
  display:block;
  padding:11px 0;
  border-bottom:1px solid var(--line);
  color:var(--paper);
  font-size:16px;
  line-height:1.2;
  transition:color .16s ease;
}
.toc li a:hover{color:var(--amber)}
.toc li a[aria-current]{color:var(--amber)}

/* ---------- 页脚 ---------- */
.foot{
  border-top:2px solid var(--amber);
  background:#0A0D12;
}
.foot-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr;
  gap:clamp(24px,4vw,48px);
  max-width:var(--max);
  margin:0 auto;
  padding:clamp(32px,5vw,60px) clamp(20px,4vw,48px);
}
.foot address{font-style:normal}
.foot-mark{
  display:grid;
  place-items:center;
  width:50px;height:50px;
  margin-bottom:18px;
  border:2px solid var(--amber);
  color:var(--amber);
  transition:background-color .18s ease,color .18s ease;
}
.foot-mark:hover{background:var(--amber);color:var(--ink)}
.foot-big{
  margin:0;
  font-size:clamp(2rem,4.6vw,3.4rem);
  font-weight:700;
  line-height:1;
  letter-spacing:-.03em;
}
.foot-list{list-style:none;margin:0;padding:0;display:grid;gap:2px}
.foot-list a{
  display:inline-block;
  padding:11px 8px 11px 0;
  color:var(--body);
  font-size:16px;
  line-height:1.2;
  transition:color .16s ease;
}
.foot-list a:hover{color:var(--amber)}

.foot-bar{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  max-width:var(--max);
  margin:0 auto;
  padding:14px clamp(20px,4vw,48px) 30px;
  border-top:2px solid var(--line);
}
.copy{margin:0;color:var(--muted);font-size:16px;letter-spacing:.04em}
.foot-mini{display:flex;gap:20px;list-style:none;margin:0;padding:0}
.foot-mini a{
  display:inline-block;
  padding:11px 0;
  color:var(--muted);
  font-size:16px;
  line-height:1.2;
}
.foot-mini a:hover{color:var(--amber)}

/* ---------- 滚动显现 ---------- */
.rv{opacity:0;transform:translateY(16px)}
.rv-in{opacity:1;transform:none;transition:opacity .45s ease,transform .45s ease}

/* ---------- 断点 ---------- */
@media (max-width:1080px){
  body{padding-left:0}
  .rail{
    position:static;
    width:auto;
    flex-direction:row;
    flex-wrap:wrap;
    align-items:center;
    border-right:0;
    border-bottom:2px solid var(--line);
    padding-bottom:12px;
  }
  .strip{width:100%}
  .rail-brand{margin:14px 12px 0}
  .rail-nav{padding:14px 12px 0}
  .rail-nav p{gap:8px}
  .layout{grid-template-columns:minmax(0,1fr);align-items:stretch}
  section{max-width:none}
  .side{
    position:static;
    order:2;
    padding:22px 0 0;
    border-left:0;
    border-top:2px solid var(--amber);
  }
  .hero-inner{grid-template-columns:minmax(0,1fr)}
  .hero-fig{order:2;max-width:560px;margin:0 auto;width:100%}
  .foot-grid{grid-template-columns:1fr 1fr}
}

@media (max-width:640px){
  body{font-size:16px}
  .hero{min-height:auto;padding:26px 0 38px}
  .hero-txt{text-align:left}
  .hero-lede{margin-left:0;margin-right:0;max-width:none}
  h1{font-size:clamp(1.9rem,9vw,2.6rem)}
  .hero-inner.solo .hero-txt{margin:0}
  .foot-grid{grid-template-columns:1fr}
  .foot-bar{flex-direction:column;align-items:flex-start}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .rv{opacity:1;transform:none}
  .hero-fig img{transform:none}
  *{transition:none !important}
}

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