@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@300;400;500;600;700&family=Syne:wght@400;500;600;700&display=swap');

:root{
  --ink:#141518;
  --ink-2:#1b1d21;
  --red:#FF4B3E;
  --cream:#EFEFE9;
  --mute:rgba(239,239,233,.64);
  --line:rgba(239,239,233,.16);
  --glass:rgba(239,239,233,.055);
  --r:3px;
  --r-lg:10px;
  --display:'Syne','Manrope',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  --body:'Manrope',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
}

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

html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--ink);
  color:var(--cream);
  font-family:var(--body);
  font-size:17px;
  line-height:1.75;
  font-weight:400;
  overflow-x:hidden;
}

img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{font-family:var(--display);line-height:1.12;letter-spacing:-.012em;margin:0;font-weight:700}
p{margin:0 0 1rem}
svg{display:block}

/* ---------- 顶栏 ---------- */
.top{
  position:relative;
  z-index:20;
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:.4rem;
  padding:.85rem clamp(1rem,4vw,2.5rem);
  border-bottom:2px solid var(--line);
}
.nav{display:flex;flex-wrap:wrap;align-items:center;gap:.15rem;min-width:0}
.nav-r{justify-content:flex-end}
.nav-link{
  display:inline-flex;
  align-items:center;
  gap:.45rem;
  min-height:42px;
  padding:.4rem .65rem;
  font-size:.92rem;
  font-weight:600;
  border-radius:var(--r);
  transition:background .18s ease,color .18s ease;
}
.nav-link:hover,.nav-link:focus-visible{background:var(--red);color:var(--ink);outline:none}
.ic{display:inline-flex}
.ic svg{width:14px;height:14px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:square}

.brand{
  display:inline-flex;
  align-items:center;
  gap:.55rem;
  min-height:44px;
  padding:.35rem .8rem;
  border:2px solid var(--cream);
  border-radius:var(--r);
  font-family:var(--display);
  font-size:1rem;
  font-weight:700;
  white-space:nowrap;
  transition:border-color .18s ease,color .18s ease;
}
.brand:hover{border-color:var(--red);color:var(--red)}
.brand-mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:26px;height:26px;
  background:var(--red);
  color:var(--ink);
  border-radius:2px;
  font-size:.82rem;
  font-weight:700;
}
.brand-logo{width:26px;height:26px;object-fit:cover;border-radius:2px}

/* ---------- 粘性锚点条 ---------- */
.anchorbar{
  position:sticky;
  top:0;
  z-index:30;
  background:rgba(20,21,24,.94);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(10px);
}
.ab-in{
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:.35rem;
  max-width:1180px;
  margin:0 auto;
  padding:.45rem clamp(1rem,4vw,2.5rem);
}
.ab-link{
  display:inline-flex;
  align-items:center;
  min-height:38px;
  padding:.3rem .75rem;
  font-size:.82rem;
  font-weight:600;
  color:var(--mute);
  border:1px solid var(--line);
  border-radius:100px;
  transition:color .18s ease,border-color .18s ease,background .18s ease;
}
.ab-link:hover,.ab-link:focus-visible{color:var(--ink);background:var(--red);border-color:var(--red);outline:none}
.ab-link.dim,.toc li.dim,.nav-link.dim{opacity:.28}

.search{
  display:flex;
  align-items:center;
  gap:.4rem;
  margin-left:auto;
  min-height:38px;
  padding:.1rem .7rem;
  border:1px solid var(--line);
  border-radius:100px;
}
.search svg{width:14px;height:14px;fill:none;stroke:var(--mute);stroke-width:1.8}
.search input{
  width:7.5rem;
  padding:.2rem 0;
  border:0;
  background:transparent;
  color:var(--cream);
  font:inherit;
  font-size:.85rem;
  outline:none;
}
.search input::placeholder{color:var(--mute)}

/* ---------- 头图 ---------- */
.hero{
  position:relative;
  overflow:hidden;
  min-height:70vh;
  display:flex;
  flex-direction:column;
  justify-content:center;
  align-items:flex-end;
  text-align:right;
  gap:1.1rem;
  padding:clamp(2.8rem,9vw,5.5rem) clamp(1rem,4vw,2.5rem) clamp(3rem,7vw,4.2rem);
  border-bottom:2px solid var(--line);
}
.hero h1{
  font-size:clamp(2.6rem,8.5vw,7rem);
  letter-spacing:-.035em;
  max-width:18ch;
}
.hero-lead{max-width:44ch;margin:0;color:var(--mute);font-size:1.02rem}
.badges{
  position:absolute;
  left:clamp(1rem,4vw,2.5rem);
  bottom:clamp(1.4rem,5vw,2.4rem);
  display:flex;
  flex-direction:column;
  align-items:flex-start;
  gap:.4rem;
}
.badge{
  display:inline-block;
  padding:.28rem .7rem;
  background:var(--red);
  color:var(--ink);
  font-size:.78rem;
  font-weight:700;
  border-radius:2px;
}

/* ---------- 主体 ---------- */
.wrap{
  display:grid;
  grid-template-columns:minmax(0,215px) minmax(0,1fr);
  gap:clamp(1.5rem,4vw,3.25rem);
  align-items:start;
  max-width:1180px;
  margin:0 auto;
  padding:clamp(2.2rem,6vw,3.8rem) clamp(1rem,4vw,2.5rem);
}

.side{
  position:sticky;
  top:4.6rem;
  padding:1.05rem;
  background:var(--glass);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  backdrop-filter:blur(12px);
}
.side h2{font-family:var(--body);font-size:.84rem;font-weight:700;letter-spacing:.2em}
.subtitle{margin:.5rem 0 .9rem;font-size:.82rem;line-height:1.6;color:var(--mute)}
.toc{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:.3rem}
.toc a{
  display:flex;
  align-items:center;
  gap:.5rem;
  min-height:42px;
  padding:.3rem .5rem;
  font-size:.87rem;
  border:1px solid transparent;
  border-radius:var(--r);
  transition:background .18s ease,color .18s ease,border-color .18s ease;
}
.toc b{font-family:var(--display);font-size:.76rem;color:var(--red)}
.toc a:hover,.toc a:focus-visible{background:var(--red);color:var(--ink);border-color:var(--red);outline:none}
.toc a:hover b{color:var(--ink)}

section{min-width:0}
section > article{
  padding:2.4rem 0;
  border-top:2px solid var(--line);
  scroll-margin-top:5.6rem;
}
section > article:first-of-type{border-top:0;padding-top:.2rem}
section h2{font-size:clamp(1.55rem,3.6vw,2.35rem);margin-bottom:.6rem}
section h3{font-size:clamp(1.12rem,2.4vw,1.35rem);margin:1.6rem 0 .55rem}
section p{max-width:66ch;color:rgba(239,239,233,.86)}
section ul,section ol{padding-left:1.2rem;max-width:66ch}
section li{margin:.35rem 0}
section a{color:var(--red);text-decoration:underline;text-underline-offset:3px}
section a:hover{text-decoration:none}
section strong{color:var(--cream)}
section blockquote{
  margin:1.4rem 0;
  padding:.9rem 1.1rem;
  background:var(--glass);
  border-left:3px solid var(--red);
  border-radius:var(--r-lg);
  backdrop-filter:blur(8px);
}
section blockquote p{margin:0;color:var(--cream)}
section table{width:100%;border-collapse:collapse;font-size:.93rem;margin:1rem 0}
section th,section td{border:1px solid var(--line);padding:.5rem .6rem;text-align:left}
section img{border-radius:var(--r-lg);margin:1rem 0}
section hr{border:0;border-top:2px solid var(--line);margin:2rem 0}

/* ---------- 滚动出现 ---------- */
.reveal{opacity:0;transform:translateY(14px);transition:opacity .45s ease,transform .45s ease}
html:not(.js) .reveal{opacity:1;transform:none}
.reveal.in{opacity:1;transform:none}

/* ---------- 页脚 ---------- */
footer{
  display:flex;
  flex-wrap:wrap;
  border-top:2px solid var(--red);
  background:var(--ink-2);
}
.cta{
  width:100%;
  max-width:1180px;
  margin:0 auto;
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:1.2rem;
  padding:clamp(2rem,5vw,3rem) clamp(1rem,4vw,2.5rem) 0;
}
.cta-t{font-family:var(--display);font-size:clamp(1.5rem,4vw,2.5rem);font-weight:700;margin:0}
.cta-btn{
  display:inline-flex;
  align-items:center;
  min-height:48px;
  padding:.5rem 1.3rem;
  background:var(--red);
  color:var(--ink);
  font-weight:700;
  border-radius:var(--r);
  transition:opacity .18s ease;
}
.cta-btn:hover{opacity:.82}
.foot{
  width:100%;
  max-width:1180px;
  margin:0 auto;
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:1.3rem;
  padding:1.5rem clamp(1rem,4vw,2.5rem) 2.2rem;
}
.f-brand a{display:inline-flex;align-items:center;gap:.5rem;font-family:var(--display);font-weight:700;font-size:.95rem;min-height:44px}
.f-brand .brand-mark{width:22px;height:22px;font-size:.72rem}
.f-nav dl{display:flex;flex-wrap:wrap;align-items:center;gap:.25rem;margin:0}
.f-nav dt{padding:.2rem .5rem;border-left:2px solid var(--red);font-size:.8rem;color:var(--mute)}
.f-nav dt a{display:inline-flex;align-items:center;min-height:40px}
.f-nav dd{display:flex;flex-wrap:wrap;gap:.1rem;margin:0}
.f-nav dd a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:.25rem .55rem;
  font-size:.87rem;
  border-radius:var(--r);
  transition:background .18s ease,color .18s ease;
}
.f-nav dd a:hover{background:var(--red);color:var(--ink)}
.f-copy{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.9rem;
  margin-left:auto;
  font-size:.82rem;
  color:var(--mute);
}
.f-copy a{display:inline-flex;align-items:center;min-height:40px;border-bottom:1px solid var(--line)}

/* ---------- 响应式 ---------- */
@media (max-width:960px){
  .wrap{grid-template-columns:minmax(0,1fr)}
  .side{position:static}
  .cta-btn{padding:.45rem 1.1rem}
}

@media (max-width:820px){
  .top{display:flex;flex-wrap:wrap;justify-content:center;gap:.35rem}
  .nav{flex:1 1 100%;justify-content:center}
  .brand{order:-1;margin:0 auto .2rem}
  .hero{min-height:60vh}
  .hero h1{max-width:100%}
  .foot{gap:.8rem}
  .f-copy{margin-left:0;width:100%}
}

@media (max-width:520px){
  body{font-size:16.5px}
  .nav-link{font-size:.87rem;padding:.35rem .5rem}
  .ab-in{gap:.25rem}
  .search{width:100%;margin-left:0}
  .search input{width:100%}
  .hero{padding-top:2.2rem}
  .badges{position:static;flex-direction:row;flex-wrap:wrap}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal{opacity:1;transform:none}
}

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