:root{
  --paper:#fdfbf7;
  --paper-2:#f5f5f5;
  --ink:#1a1a1a;
  --rule:#e2e0da;
  --soft:#6b665d;
  --bar:58px;
  --maxw:1140px;
  --radius:28px;
}
*,*::before,*::after{box-sizing:border-box}
html{
  scroll-behavior:smooth;
  overflow-x:hidden;
  -webkit-text-size-adjust:100%;
}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:"Karla",-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:60;
  pointer-events:none;
  opacity:.055;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='180' height='180'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.86' numOctaves='2' stitchTiles='stitch'/></filter><rect width='180' height='180' filter='url(%23n)' opacity='0.6'/></svg>");
}
h1,h2,h3,h4{
  font-family:"Playfair Display SC",Georgia,"Songti SC","Times New Roman",serif;
  font-weight:400;
  line-height:1.14;
  letter-spacing:.005em;
  margin:0;
}
a{color:inherit;text-decoration:none}
a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible{
  outline:2px solid var(--ink);
  outline-offset:3px;
}
p{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
.shell,.wrap{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 16px}

/* ---- 顶部条 ---- */
.bar{
  position:sticky;
  top:0;
  z-index:32;
  height:var(--bar);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  padding:0 14px;
  background:var(--paper);
  border-bottom:1px solid var(--ink);
}
.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  font-family:"Playfair Display SC",Georgia,"Songti SC",serif;
  font-size:19px;
  letter-spacing:.1em;
  white-space:nowrap;
}
.brand::before{
  content:"";
  width:13px;
  height:13px;
  flex:none;
  background:var(--ink);
  border-radius:3px;
}
.bar-right{display:flex;align-items:center;gap:8px}
.cta{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 16px;
  background:var(--ink);
  color:var(--paper);
  border-radius:999px;
  font-size:16px;
  letter-spacing:.09em;
  white-space:nowrap;
}

/* ---- 折叠菜单 ---- */
.drill{position:relative}
.drill summary{
  list-style:none;
  cursor:pointer;
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:0 15px;
  border:1px solid var(--ink);
  border-radius:999px;
  font-size:16px;
  letter-spacing:.09em;
  white-space:nowrap;
}
.drill summary::-webkit-details-marker{display:none}
.drill summary::before{
  content:"";
  width:10px;
  height:10px;
  flex:none;
  border:1px solid var(--ink);
  border-radius:2px;
  transition:background .1s linear;
}
.drill[open] summary{background:var(--ink);color:var(--paper)}
.drill[open] summary::before{background:var(--paper);border-color:var(--paper)}
.drill-menu{
  position:absolute;
  right:0;
  top:calc(100% + 9px);
  z-index:45;
  width:236px;
  padding:8px;
  background:var(--paper);
  border:1px solid var(--ink);
  border-radius:20px;
  box-shadow:7px 8px 0 -1px rgba(26,26,26,.14);
}
.drill-menu li{opacity:0;transition:opacity .1s linear}
.drill[open] .drill-menu li{opacity:1}
.drill-menu li:nth-child(1){transition-delay:0ms}
.drill-menu li:nth-child(2){transition-delay:30ms}
.drill-menu li:nth-child(3){transition-delay:60ms}
.drill-menu li:nth-child(4){transition-delay:90ms}
.drill-menu li:nth-child(5){transition-delay:120ms}
.drill-menu li:nth-child(6){transition-delay:150ms}
.drill-menu li:nth-child(7){transition-delay:180ms}
.drill-menu a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:6px 12px;
  border-radius:12px;
  font-size:16px;
  letter-spacing:.03em;
}
.drill-menu a::before{
  content:"";
  width:6px;
  height:6px;
  flex:none;
  margin-right:11px;
  border-radius:50%;
  background:var(--ink);
  opacity:.4;
}
.drill-menu a:hover{background:var(--paper-2)}

/* ---- 粘性锚点条 ---- */
.anchors{
  position:sticky;
  top:var(--bar);
  z-index:30;
  display:flex;
  overflow-x:auto;
  background:var(--paper);
  border-bottom:1px solid var(--ink);
  scrollbar-width:none;
}
.anchors::-webkit-scrollbar{display:none}
.anchors a{
  flex:none;
  display:flex;
  align-items:center;
  min-height:46px;
  padding:0 15px;
  font-size:16px;
  letter-spacing:.06em;
  white-space:nowrap;
  border-right:1px solid var(--rule);
}
.anchors a:hover{background:var(--paper-2)}

/* ---- 首屏 ---- */
.hero{
  position:relative;
  min-height:100vh;
  display:flex;
  align-items:center;
  border-bottom:1px solid var(--ink);
  overflow:hidden;
}
.hero .shell{padding-top:62px;padding-bottom:52px}
.badge{
  display:inline-block;
  margin-bottom:26px;
  padding:6px 15px;
  border:1px solid var(--ink);
  border-radius:999px;
  font-size:16px;
  letter-spacing:.16em;
  transform:rotate(-2deg);
}
.hero h1{
  font-size:clamp(38px,9.2vw,104px);
  line-height:1.06;
  letter-spacing:-.005em;
  margin-bottom:24px;
  max-width:15em;
  overflow-wrap:break-word;
}
.lede{
  max-width:34em;
  font-size:18px;
  line-height:1.7;
  color:#3d3a34;
  margin-bottom:34px;
}
.hero-cta{
  display:inline-flex;
  align-items:center;
  min-height:52px;
  padding:0 26px;
  border:1px solid var(--ink);
  border-radius:999px;
  font-size:17px;
  letter-spacing:.1em;
}
.hero-cta::after{content:"";width:22px;height:1px;margin-left:12px;background:var(--ink)}
.hero-cta:hover{background:var(--ink);color:var(--paper)}

/* ---- 正文 ---- */
main{display:block}
.read{
  display:grid;
  grid-template-columns:1fr;
  gap:30px;
  padding:28px 0 60px;
}
.prose{
  min-width:0;
  overflow-wrap:break-word;
}
.prose > section{
  padding:42px 0;
  border-top:1px solid var(--rule);
  scroll-margin-top:calc(var(--bar) + 58px);
}
.prose > section:first-child{border-top:0;padding-top:6px}
.prose h2{font-size:clamp(25px,4.6vw,38px);margin-bottom:14px}
.prose h3{font-size:21px;margin:30px 0 10px}
.prose p{margin-bottom:18px;max-width:38em}
.prose ul,.prose ol{padding-left:22px;margin-bottom:18px}
.prose ul{list-style:square}
.prose ol{list-style:decimal}
.prose li{margin-bottom:8px}
.prose a{border-bottom:1px solid var(--ink)}
.prose a:hover{background:var(--paper-2)}
.prose blockquote{
  margin:24px 0;
  padding:18px 22px;
  background:var(--paper-2);
  border-radius:var(--radius);
  font-family:"Playfair Display SC",Georgia,"Songti SC",serif;
  font-size:18px;
}
.prose blockquote p:last-child{margin-bottom:0}
.prose img{display:block;max-width:100%;height:auto;margin:24px 0;border-radius:var(--radius)}
.prose figure{margin:24px 0}
.prose table{width:100%;border-collapse:collapse;font-size:16px;margin-bottom:18px}
.prose th,.prose td{border:1px solid var(--rule);padding:9px 11px;text-align:left}
.prose pre{overflow-x:auto;padding:16px;background:var(--paper-2);border-radius:16px;font-size:16px;line-height:1.6}
.prose code{font-size:16px}
.prose hr{border:0;border-top:1px solid var(--rule);margin:26px 0}

/* ---- 侧栏 ---- */
.rail{
  align-self:start;
  background:var(--paper-2);
  border-radius:var(--radius);
  padding:22px 20px 18px;
}
.rail h2{font-size:21px;letter-spacing:.03em}
.rail .subtitle{
  font-size:16px;
  letter-spacing:.14em;
  color:var(--soft);
  margin:2px 0 12px;
}
.rail-list{counter-reset:r}
.rail-list li{
  opacity:0;
  transition:opacity .12s linear;
}
.rail-list li:nth-child(1){transition-delay:0ms}
.rail-list li:nth-child(2){transition-delay:25ms}
.rail-list li:nth-child(3){transition-delay:50ms}
.rail-list li:nth-child(4){transition-delay:75ms}
.rail-list li:nth-child(5){transition-delay:100ms}
.rail-list li:nth-child(6){transition-delay:125ms}
.rail-list li:nth-child(7){transition-delay:150ms}
.rail-list li:nth-child(n+8){transition-delay:170ms}
.rail.in .rail-list li{opacity:1}
.rail-list a{
  display:flex;
  align-items:center;
  gap:11px;
  min-height:42px;
  padding:3px 0;
  font-size:16px;
  border-bottom:1px solid #e4e2dc;
}
.rail-list li:last-child a{border-bottom:0}
.rail-list a::before{
  counter-increment:r;
  content:counter(r,decimal-leading-zero);
  flex:none;
  font-family:"Playfair Display SC",Georgia,serif;
  font-size:13px;
  letter-spacing:.1em;
  color:var(--soft);
}
.rail-list a:hover{color:#000;background:#ecebe5}

/* ---- 页脚 ---- */
.foot{
  border-top:1px solid var(--ink);
  padding-bottom:26px;
}
.foot > article{
  width:100%;
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 16px;
}
.foot-top{
  display:grid;
  grid-template-columns:1fr;
  gap:24px;
  padding-top:38px;
  padding-bottom:28px;
  border-bottom:1px solid var(--rule);
}
.foot-brand h2{font-size:26px;letter-spacing:.06em;margin-bottom:14px}
.foot-top-link{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  padding:0 15px;
  border:1px solid var(--ink);
  border-radius:999px;
  font-size:16px;
}
.foot-top-link:hover{background:var(--ink);color:var(--paper)}
.foot-links ul{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:0 18px;
}
.foot-links a{
  display:flex;
  align-items:center;
  min-height:42px;
  font-size:16px;
  border-bottom:1px solid var(--rule);
}
.foot-links a:hover{background:var(--paper-2)}
.foot-form{padding:26px 16px 30px}
.foot-form form{
  display:flex;
  gap:10px;
  max-width:520px;
}
.foot-form input{
  flex:1;
  min-width:0;
  min-height:50px;
  padding:0 16px;
  background:var(--paper);
  border:1px solid var(--ink);
  border-radius:999px;
  font-family:inherit;
  font-size:16px;
  color:var(--ink);
}
.foot-form input::placeholder{color:var(--soft)}
.foot-form button{
  flex:none;
  min-height:50px;
  padding:0 24px;
  background:var(--ink);
  color:var(--paper);
  border:1px solid var(--ink);
  border-radius:999px;
  font-family:inherit;
  font-size:16px;
  letter-spacing:.09em;
  cursor:pointer;
}
.foot-base{
  max-width:var(--maxw);
  margin:0 auto;
  padding:18px 16px 0;
  border-top:1px solid var(--rule);
  text-align:center;
  font-size:16px;
  letter-spacing:.09em;
  color:var(--soft);
}

/* ---- 滚动显现 ---- */
.js .rev{opacity:0}
.js .rev.in{opacity:1;transition:opacity .14s linear}

/* ---- 断点 ---- */
@media (min-width:700px){
  .bar{padding:0 22px}
  .shell,.wrap,.foot > article,.foot-base{padding-left:24px;padding-right:24px}
  .foot-top{grid-template-columns:1.1fr 1fr;gap:44px}
  .foot-links ul{grid-template-columns:1fr}
}
@media (min-width:900px){
  .hero .badge{
    position:absolute;
    top:13%;
    right:24px;
    margin:0;
    transform:rotate(6deg);
  }
  .hero h1{max-width:13em}
}
@media (min-width:1000px){
  .read{
    grid-template-columns:minmax(0,1fr) 262px;
    gap:54px;
    padding-top:44px;
  }
  .rail{position:sticky;top:calc(var(--bar) + 66px)}
  .foot-links ul{grid-template-columns:1fr 1fr}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js .rev,.js .rev.in{opacity:1;transition:none}
  .rail-list li,.drill-menu li{transition:none;opacity:1}
  .drill summary::before{transition:none}
}

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