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

:root{
  --ink:#14100E;
  --ink-soft:#1B1613;
  --paper:#F3EDE4;
  --gold:#A8763E;
  --line:rgba(168,118,62,.26);
  --line-soft:rgba(168,118,62,.14);
  --muted:rgba(243,237,228,.66);
  --serif:'Playfair Display',Georgia,'Songti SC','Times New Roman',serif;
  --sans:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
}

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

html{
  background:var(--ink);
  color-scheme:dark;
  scroll-behavior:smooth;
  overflow-x:hidden;
  -webkit-text-size-adjust:100%;
}

body{
  margin:0;
  background:var(--ink);
  color:var(--paper);
  font-family:var(--sans);
  font-size:1.0625rem;
  line-height:1.75;
  font-weight:400;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

body.lock{overflow:hidden}

img{display:block;max-width:100%;height:auto}
a{color:var(--gold);text-decoration:none;transition:color .25s ease}
a:hover{color:var(--paper)}
h1,h2,h3{font-family:var(--serif);font-weight:500;letter-spacing:-.012em;line-height:1.18;margin:0}
p{margin:0}
::selection{background:var(--gold);color:var(--ink)}
:focus-visible{outline:2px solid var(--gold);outline-offset:3px}

.skip{
  position:absolute;top:10px;left:14px;z-index:120;
  padding:10px 16px;border-radius:4px;
  background:var(--gold);color:var(--ink);font-size:1rem;
  transform:translateY(-220%);transition:transform .25s ease;
}
.skip:focus{transform:none;color:var(--ink)}

/* ---------- 顶栏 ---------- */
.topbar{
  position:sticky;top:0;z-index:70;
  background:rgba(20,16,14,.86);
  -webkit-backdrop-filter:blur(16px) saturate(130%);
  backdrop-filter:blur(16px) saturate(130%);
  border-bottom:1px solid var(--line);
}

.topbar__row{
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:12px;
  max-width:1180px;
  margin:0 auto;
  padding:8px 20px;
}

.topbar__right{display:flex;align-items:center;gap:8px;justify-self:end}
.nav{min-width:0}
.nav__list{display:flex;align-items:center;gap:2px;list-style:none;margin:0;padding:0}
.nav--l .nav__list{justify-content:flex-end}
.nav__link{
  position:relative;display:block;
  padding:12px 10px;
  font-size:1rem;line-height:1.4;
  color:var(--paper);opacity:.8;border-radius:4px;
  white-space:nowrap;
}
.nav__link::after{
  content:'';position:absolute;left:10px;right:10px;bottom:7px;height:1px;
  background:var(--gold);transform:scaleX(0);transform-origin:left;
  transition:transform .35s cubic-bezier(.2,.7,.3,1);
}
.nav__link:hover{opacity:1;color:var(--paper)}
.nav__link:hover::after{transform:scaleX(1)}

.brand{
  display:inline-flex;align-items:center;gap:10px;
  min-height:44px;padding:6px 12px;
  color:var(--paper);font-family:var(--serif);
  font-size:1.125rem;letter-spacing:.06em;white-space:nowrap;
}
.brand:hover{color:var(--gold)}
.brand__mark{
  width:16px;height:16px;border:1px solid var(--gold);border-radius:50%;
  position:relative;flex:none;
}
.brand__mark::after{
  content:'';position:absolute;inset:4px;border-radius:50%;background:var(--gold);
}

.search{display:flex;align-items:center}
.search__input{
  width:130px;min-height:44px;padding:0 12px;
  background:rgba(243,237,228,.045);
  border:1px solid var(--line);border-radius:4px;
  color:var(--paper);font-family:var(--sans);font-size:1rem;
  transition:border-color .25s ease,background .25s ease;
}
.search__input::placeholder{color:var(--muted)}
.search__input:focus{outline:none;border-color:var(--gold);background:rgba(243,237,228,.08)}

.burger{
  display:inline-flex;align-items:center;gap:9px;
  min-height:44px;padding:0 13px;
  background:transparent;border:1px solid var(--line);border-radius:4px;
  color:var(--paper);font-family:var(--sans);font-size:1rem;
  cursor:pointer;transition:border-color .25s ease,color .25s ease;
}
.burger:hover{border-color:var(--gold);color:var(--gold)}
.burger__bars{display:grid;gap:4px;width:16px}
.burger__bars i{display:block;height:1px;background:currentColor}

/* ---------- 二级粘性锚点条 ---------- */
.rail{border-top:1px solid var(--line-soft)}
.rail__list{
  display:flex;gap:6px;list-style:none;
  margin:0 auto;padding:6px 20px;max-width:1180px;
  overflow-x:auto;scrollbar-width:none;
}
.rail__list::-webkit-scrollbar{display:none}
.rail__link{
  display:inline-flex;align-items:center;gap:8px;
  min-height:44px;padding:8px 13px;white-space:nowrap;
  font-size:1rem;color:var(--muted);
  border:1px solid transparent;border-radius:999px;
  transition:color .25s ease,border-color .25s ease,background .25s ease;
}
.rail__link:hover,.rail__link.is-active{
  color:var(--gold);border-color:var(--line);background:rgba(168,118,62,.09);
}
.rail__num{font-size:1rem;letter-spacing:.1em;opacity:.7}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;isolation:isolate;
  display:grid;place-items:center;
  min-height:74vh;
  padding:48px 20px 64px;
  text-align:center;overflow:hidden;
}
.hero__media{
  position:absolute;inset:-16% 0;z-index:-1;
  will-change:transform;
}
.hero__img{
  position:absolute;inset:0;
  width:100%;height:100%;object-fit:cover;
  filter:saturate(.82) contrast(1.06) brightness(.9);
}
.hero__veil{
  position:absolute;inset:0;
  background:
    radial-gradient(ellipse at 50% 42%,rgba(20,16,14,.3),rgba(20,16,14,.94) 74%),
    linear-gradient(to bottom,rgba(20,16,14,.92),rgba(20,16,14,.4) 38%,rgba(20,16,14,.97) 97%);
}
.hero__dots{
  position:absolute;inset:0;opacity:.3;
  background-image:radial-gradient(rgba(168,118,62,.6) 1px,transparent 1px);
  background-size:28px 28px;
  -webkit-mask-image:radial-gradient(ellipse at 50% 40%,#000 18%,transparent 76%);
  mask-image:radial-gradient(ellipse at 50% 40%,#000 18%,transparent 76%);
}
.hero__inner{
  position:relative;z-index:2;
  max-width:44rem;
  will-change:transform,opacity;
}
.hero__kicker{
  font-size:1rem;letter-spacing:.34em;
  color:var(--gold);margin-bottom:18px;
}
.hero__title{
  font-size:clamp(2.2rem,6.4vw,4.6rem);
  line-height:1.08;letter-spacing:-.02em;
  margin:0 auto 20px;
}
.hero__title::after{
  content:'';display:block;width:64px;height:1px;
  margin:26px auto 0;background:var(--gold);
}
.hero__lede{
  max-width:31em;margin:0 auto 30px;
  color:var(--muted);font-size:1.0625rem;line-height:1.8;
}
.hero__cta{margin:0}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:48px;padding:12px 30px;
  border:1px solid var(--gold);border-radius:4px;
  color:var(--gold);font-size:1rem;letter-spacing:.18em;
  transition:background .3s ease,color .3s ease;
}
.btn:hover{background:var(--gold);color:var(--ink)}

/* ---------- 正文 ---------- */
.doc{
  display:grid;
  grid-template-columns:minmax(0,1fr) 248px;
  gap:40px 56px;
  max-width:1120px;
  margin:0 auto;
  padding:16px 24px 104px;
}
.doc__figure{
  grid-column:1 / -1;grid-row:1;
  margin:0;border:1px solid var(--line);border-radius:4px;overflow:hidden;
  border-bottom:2px solid var(--gold);
}
.doc__figure img{width:100%}
.doc__body{grid-column:1;grid-row:2;min-width:0}
.doc__body > div{
  padding-bottom:56px;margin-bottom:56px;
  border-bottom:1px solid var(--line-soft);
  scroll-margin-top:150px;
}
.doc__body > div:last-child{border-bottom:0;margin-bottom:0;padding-bottom:16px}

.doc__body h2{
  font-size:clamp(1.7rem,3.4vw,2.5rem);
  margin:0 0 20px;
}
.doc__body h2 small{display:block;margin-bottom:10px}
.doc__body h3{font-size:1.35rem;margin:30px 0 12px}
.doc__body small,.toc__kicker{
  display:block;font-size:1rem;letter-spacing:.22em;
  color:var(--gold);margin-bottom:8px;
}
.doc__body p{margin:0 0 18px;color:rgba(243,237,228,.87)}
.doc__body ul,.doc__body ol{
  margin:0 0 20px;padding-left:1.35em;
  color:rgba(243,237,228,.87);
}
.doc__body li{margin-bottom:8px}
.doc__body li::marker{color:var(--gold)}
.doc__body blockquote{
  margin:26px 0;padding:2px 0 2px 20px;
  border-left:2px solid var(--gold);color:var(--muted);
}
.doc__body figure{margin:26px 0}
.doc__body img{border:1px solid var(--line);border-radius:4px}
.doc__body table{display:block;width:100%;overflow-x:auto;border-collapse:collapse;font-size:1rem}
.doc__body th,.doc__body td{border-bottom:1px solid var(--line-soft);padding:10px 12px;text-align:left}
.doc__body hr{border:0;border-top:1px solid var(--line-soft);margin:32px 0}

/* ---------- 右侧目录 ---------- */
.doc__aside{
  grid-column:2;grid-row:2;align-self:start;
  position:sticky;top:132px;
  padding:20px 18px 18px;
  border:1px solid var(--line);border-bottom:2px solid var(--gold);
  border-radius:4px;background:rgba(243,237,228,.035);
}
.toc__kicker{margin-bottom:6px}
.toc__title{font-size:1.35rem;margin-bottom:14px}
.toc__list{list-style:none;margin:0;padding:0;display:grid;gap:1px}
.toc__list a{
  display:flex;gap:10px;align-items:baseline;
  min-height:40px;padding:8px 4px;
  font-size:1rem;color:var(--muted);
  border-bottom:1px solid var(--line-soft);
  transition:color .25s ease,padding-left .25s ease;
}
.toc__list a:hover,.toc__list a.is-active{color:var(--gold);padding-left:8px}
.toc__num{font-size:1rem;letter-spacing:.1em;color:var(--gold);opacity:.65;flex:none}
.toc__count{
  margin:16px 0 0;font-family:var(--serif);font-size:1.25rem;
  letter-spacing:.14em;color:var(--gold);
}

/* ---------- 页脚 ---------- */
.foot{
  position:relative;
  border-top:1px solid var(--line);
  padding:88px 24px 48px;
  text-align:center;overflow:hidden;
}
.foot::before{
  content:'';position:absolute;inset:0;pointer-events:none;opacity:.22;
  background-image:radial-gradient(rgba(168,118,62,.6) 1px,transparent 1px);
  background-size:26px 26px;
  -webkit-mask-image:radial-gradient(ellipse at 50% 100%,#000 5%,transparent 70%);
  mask-image:radial-gradient(ellipse at 50% 100%,#000 5%,transparent 70%);
}
.foot__cta{
  position:relative;
  margin:0 0 44px;
  font-family:var(--serif);
  font-size:clamp(2rem,7.6vw,4.2rem);
  line-height:1.12;letter-spacing:-.01em;
}
.foot__cta a{
  display:inline-block;padding-bottom:8px;
  color:var(--paper);border-bottom:1px solid var(--gold);
}
.foot__cta a:hover{color:var(--gold)}
.foot__copy{
  position:relative;display:block;
  font-size:1rem;letter-spacing:.14em;color:var(--muted);
}

/* ---------- 全屏菜单 ---------- */
.menu-panel{
  position:fixed;inset:0;z-index:90;
  display:grid;align-content:center;gap:26px;
  padding:80px 24px 40px;
  background:rgba(20,16,14,.975);
  opacity:0;visibility:hidden;
  transition:opacity .38s ease,visibility .38s ease;
}
.menu-panel.is-open{opacity:1;visibility:visible}
.menu-panel__head{
  position:absolute;top:0;left:0;right:0;
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 18px;border-bottom:1px solid var(--line);
}
.menu-panel__brand{font-family:var(--serif);font-size:1.125rem;color:var(--gold)}
.menu-panel__close{
  min-height:44px;padding:0 14px;
  background:transparent;border:1px solid var(--line);border-radius:4px;
  color:var(--paper);font-family:var(--sans);font-size:1rem;cursor:pointer;
}
.menu-panel__close:hover{border-color:var(--gold);color:var(--gold)}
.menu-panel__nav{width:100%;max-width:560px;margin:0 auto}
.menu-panel__list{list-style:none;margin:0;padding:0}
.menu-panel__list a{
  display:flex;gap:16px;align-items:baseline;
  min-height:52px;padding:12px 4px;
  font-family:var(--serif);font-size:clamp(1.35rem,5vw,1.9rem);
  color:var(--paper);border-bottom:1px solid var(--line-soft);
}
.menu-panel__list a:hover{color:var(--gold)}
.menu-panel__list a span{
  font-family:var(--sans);font-size:1rem;
  letter-spacing:.12em;color:var(--gold);flex:none;
}
.menu-panel .search{width:100%;max-width:560px;margin:0 auto}
.menu-panel .search__input{width:100%}

/* ---------- 动效 ---------- */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .8s ease,transform .8s cubic-bezier(.2,.7,.3,1)}
.reveal.in{opacity:1;transform:none}
@keyframes pulseGold{0%{background:rgba(168,118,62,.18)}100%{background:transparent}}
.pulse{animation:pulseGold 1.5s ease-out}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
  .pulse{animation:none}
  *{transition-duration:.01ms !important}
}

/* ---------- 窄屏 ---------- */
@media (max-width:900px){
  .topbar__row{grid-template-columns:1fr auto;padding:6px 14px}
  .nav{display:none}
  .brand{justify-self:start;padding-left:0}
  .topbar .search{display:none}
  .rail__list{padding:6px 12px}
  .hero{min-height:72vh;padding:40px 18px 56px}
  .doc{grid-template-columns:1fr;gap:26px;padding:14px 18px 72px}
  .doc__figure{grid-column:1;grid-row:1}
  .doc__aside{grid-column:1;grid-row:2;position:static}
  .doc__aside .toc__list{grid-template-columns:1fr 1fr;gap:0 16px}
  .doc__aside .toc__list a{border-bottom:1px solid var(--line-soft)}
  .doc__body{grid-row:3}
  .doc__body > div{padding-bottom:44px;margin-bottom:44px;scroll-margin-top:116px}
  .foot{padding:64px 18px 40px}
}

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