@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap');

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

:root{
  --bg:#101820;
  --bg-deep:#0b1119;
  --bg-soft:#162230;
  --ink:#F2ECE3;
  --amber:#E8B04B;
  --line:rgba(242,236,227,.12);
  --line-2:rgba(232,176,75,.3);
  --muted:rgba(242,236,227,.68);
}

html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:Inter,-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:17px;
  line-height:1.78;
  letter-spacing:.01em;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img{max-width:100%;height:auto;display:block}
a{color:inherit}
p{margin:0 0 1.05em}
h1,h2,h3,h4{font-weight:800;line-height:1.22;letter-spacing:-.02em;margin:0}
:focus-visible{outline:2px solid var(--amber);outline-offset:3px}

.pulse{display:inline-block;width:8px;height:8px;flex:none;border-radius:50%;background:var(--amber);box-shadow:0 0 0 4px rgba(232,176,75,.16)}

/* ---------- 顶部 ---------- */
.masthead{position:relative;z-index:30}
.stripe{
  display:flex;align-items:center;justify-content:center;gap:.65rem;
  margin:0;padding:.5rem 1.25rem;font-size:16px;color:var(--muted);
  background:var(--bg-deep);border-bottom:1px solid var(--line);
}
.stripe-text{max-width:72ch;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}

.bar{
  position:sticky;top:0;z-index:40;
  display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:1rem;
  padding:.7rem 1.25rem;
  background:rgba(16,24,32,.86);
  backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.navs{display:contents}
.nav{min-width:0}
.nav-a{grid-column:1;grid-row:1;justify-self:end}
.nav-b{grid-column:3;grid-row:1;justify-self:start}
.nav ol{display:flex;gap:.4rem;list-style:none;margin:0;padding:0}
.nav a{
  display:inline-flex;align-items:center;min-height:44px;padding:.4rem .9rem;
  font-size:16px;text-decoration:none;white-space:nowrap;
  border:1px solid transparent;border-radius:999px;
  background:rgba(242,236,227,.06);
  transition:background .22s ease,color .22s ease,border-color .22s ease,transform .22s ease;
}
.nav a:hover,.nav a:focus-visible{background:var(--amber);color:var(--bg);border-color:var(--amber);transform:translateY(-1px)}
.nav a[aria-current]{background:rgba(232,176,75,.16);border-color:var(--line-2);color:var(--amber)}

.brand{
  grid-column:2;grid-row:1;
  display:inline-flex;align-items:center;gap:.5rem;min-height:44px;
  padding:.4rem .95rem;text-decoration:none;
  border:1px solid var(--line-2);border-radius:999px;
  background:rgba(232,176,75,.08);
  transition:background .22s ease;
}
.brand:hover{background:rgba(232,176,75,.18)}
.brand-mark{width:26px;height:26px;border-radius:50%;object-fit:cover}
.brand-text{font-weight:700;letter-spacing:.06em;font-size:16px;white-space:nowrap}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;isolation:isolate;overflow:hidden;
  min-height:100svh;display:flex;flex-direction:column;justify-content:flex-end;
  padding:6rem 1.25rem 4.5rem;
  border-bottom:1px solid var(--line);
}
.hero-layers{position:absolute;inset:0;z-index:-3}
.layer{position:absolute;inset:-25% -10%;display:block;will-change:transform}
.l1{background:radial-gradient(48% 44% at 22% 28%,rgba(232,176,75,.34),transparent 70%)}
.l2{background:radial-gradient(44% 40% at 80% 62%,rgba(232,176,75,.17),transparent 72%)}
.l3{background:radial-gradient(62% 52% at 48% 98%,rgba(242,236,227,.13),transparent 70%)}
.hero-frame{position:absolute;inset:0;z-index:-2}
.hero-frame img{width:100%;height:100%;object-fit:cover;opacity:.55;filter:grayscale(.35) contrast(1.06)}
.hero-mask{
  position:absolute;inset:0;z-index:-1;
  background:linear-gradient(to top,var(--bg) 4%,rgba(16,24,32,.86) 44%,rgba(16,24,32,.5) 78%,rgba(16,24,32,.72));
  pointer-events:none;
}
.hero-inner{width:100%;max-width:900px}
.hero-badge{
  display:inline-flex;align-items:center;gap:.55rem;
  padding:.35rem 1rem;font-size:16px;letter-spacing:.16em;
  border:1px solid var(--line-2);border-radius:999px;
  background:rgba(16,24,32,.55);backdrop-filter:blur(6px);
}
.hero h1{
  margin:1.1rem 0 0;
  font-size:clamp(2.15rem,7.6vw,4.4rem);
  line-height:1.06;letter-spacing:-.045em;
  text-shadow:0 18px 60px rgba(0,0,0,.45);
  overflow-wrap:break-word;
}

/* ---------- 正文骨架 ---------- */
main{display:block}
.stage{
  display:grid;grid-template-columns:minmax(0,200px) minmax(0,1fr);gap:3rem;
  align-items:start;max-width:1140px;margin:0 auto;padding:4.5rem 1.25rem 2rem;
}

.rail{
  position:sticky;top:96px;align-self:start;
  padding:.2rem 0 .2rem 1.1rem;border-left:2px solid var(--line-2);
}
.rail small{display:block;font-size:16px;letter-spacing:.26em;color:var(--amber);margin-bottom:.15rem}
.rail h2{font-size:1.3rem;margin:0 0 .85rem}
.rail-list{list-style:none;margin:0;padding:0;display:grid;gap:.1rem}
.rail-list a{
  display:flex;align-items:center;min-height:44px;padding:.35rem .2rem;
  font-size:16px;text-decoration:none;color:var(--muted);
  border-bottom:1px dashed rgba(242,236,227,.1);
  transition:color .22s ease;
}
.rail-list a:hover,.rail-list a[aria-current]{color:var(--amber)}

.prose{max-width:70ch;min-width:0}
.prose article{padding:3rem 0;border-top:1px solid var(--line);scroll-margin-top:120px}
.prose article:first-child{border-top:0;padding-top:0}
main article[id]{scroll-margin-top:120px}
.prose small{display:block;font-size:16px;letter-spacing:.24em;color:var(--amber);margin-bottom:.3rem}
.prose h2{font-size:clamp(1.5rem,3.4vw,2.05rem);margin:0 0 1rem}
.prose h3{font-size:1.25rem;margin:2rem 0 .7rem;color:var(--amber)}
.prose h4{font-size:1.1rem;margin:1.5rem 0 .5rem}
.prose ul,.prose ol{margin:0 0 1.15em;padding-left:1.35rem}
.prose li{margin:.35rem 0}
.prose a{color:var(--amber);text-underline-offset:3px}
.prose img{width:100%;margin:1.3rem 0;border:1px solid var(--line)}
.prose blockquote{margin:1.4rem 0;padding:.35rem 0 .35rem 1.1rem;border-left:2px solid var(--amber);color:var(--muted)}
.prose table{width:100%;border-collapse:collapse;margin:1.3rem 0;font-size:16px}
.prose th,.prose td{border-bottom:1px solid var(--line);padding:.6rem .5rem;text-align:left;vertical-align:top}
.prose th{color:var(--amber);font-weight:700}
.prose code{background:rgba(242,236,227,.09);padding:.1em .38em;font-size:.95em}
.prose strong{color:var(--amber)}
.prose hr{border:0;border-top:1px solid var(--line);margin:2rem 0}

/* ---------- 页脚 ---------- */
.foot{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:1rem;
  margin-top:3.5rem;padding:1.9rem 1.25rem;
  background:var(--bg-deep);border-top:1px solid var(--line);
}
.foot article{margin:0}
.foot p{margin:0;font-size:16px;color:var(--muted)}
.foot-brand{font-weight:800;letter-spacing:.16em;text-decoration:none;font-size:16px}
.foot-brand:hover{color:var(--amber)}
.to-top{
  display:inline-flex;align-items:center;min-height:44px;padding:.35rem 1.05rem;
  font-size:16px;text-decoration:none;border:1px solid var(--line-2);border-radius:999px;
  transition:background .22s ease,color .22s ease;
}
.to-top:hover{background:var(--amber);color:var(--bg)}

/* ---------- 滚动揭示 ---------- */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .8s ease,transform .85s cubic-bezier(.2,.7,.2,1);will-change:opacity,transform}
.reveal.in{opacity:1;transform:none}

/* ---------- 移动端 ---------- */
@media (max-width:880px){
  .bar{position:static;display:flex;flex-direction:column;gap:.55rem;padding:.65rem .8rem}
  .navs{display:flex;width:100%;gap:.5rem;overflow-x:auto;scrollbar-width:none;padding-bottom:2px}
  .navs::-webkit-scrollbar{display:none}
  .nav ol{flex-wrap:nowrap}
  .brand{width:100%;justify-content:center}
  .hero{padding:4rem 1rem 3.5rem;min-height:92svh}
  .stage{grid-template-columns:1fr;gap:1.75rem;padding:2.75rem 1rem 1.5rem}
  .rail{position:static;border-left:0;border-top:2px solid var(--line-2);padding:1rem 0 0}
  .rail-list{display:flex;flex-wrap:wrap;gap:.4rem}
  .rail-list a{border:1px solid var(--line);border-radius:999px;padding:.3rem .85rem}
  .prose article{padding:2.25rem 0;scroll-margin-top:24px}
  main article[id]{scroll-margin-top:24px}
  .foot{padding:1.5rem 1rem}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
  .layer{transform:none!important}
  .nav a,.brand,.to-top{transition:none}
  .nav a:hover,.nav a:focus-visible{transform:none}
}

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