*,*::before,*::after{box-sizing:border-box}
:root{
  --ink:#1f1f1f;
  --paper:#ffffff;
  --ash:#f5f5f5;
  --line:rgba(31,31,31,.16);
  --soft:rgba(31,31,31,.62);
  --e1:0 1px 2px rgba(31,31,31,.08);
  --e2:0 6px 16px rgba(31,31,31,.10);
  --e3:0 14px 34px rgba(31,31,31,.16);
  --e4:0 28px 64px rgba(31,31,31,.24);
  --z1:1;--z2:2;--z3:3;--z4:4;
}
html{
  scroll-behavior:smooth;
  overflow-x:hidden;
  -webkit-text-size-adjust:100%;
}
body{
  margin:0;
  padding-bottom:84px;
  font-family:'Didact Gothic',"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  font-size:17px;
  line-height:1.75;
  color:var(--ink);
  background:var(--ash);
  overflow-x:hidden;
}
img{max-width:100%}
a{color:var(--ink)}
h1,h2,h3,h4{font-family:'Poiret One',"PingFang SC","Microsoft YaHei",system-ui,sans-serif;font-weight:400;line-height:1.2}
p{margin:0 0 18px}
ul,ol{list-style:none;margin:0;padding:0}

[id]{scroll-margin-top:24px;scroll-margin-bottom:104px}

.wrap{
  max-width:1180px;
  margin:0 auto;
  padding:0 clamp(14px,4vw,32px);
}

/* ---------- 首屏：层叠 ---------- */
.hero{
  position:relative;
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);
  align-items:center;
  min-height:70vh;
  padding:clamp(24px,5vh,52px) 0 clamp(38px,6vh,64px);
}
.hero-media{
  position:relative;
  z-index:var(--z1);
  min-height:360px;
  height:100%;
  background:var(--ink);
  box-shadow:var(--e3);
  will-change:transform;
  overflow:hidden;
}
.hero-media .shot{
  position:absolute;
  inset:0;
  margin:0;
  opacity:0;
  transition:opacity .9s ease;
}
.hero-media .shot.is-on{opacity:1}
.hero-media img{
  width:100%;
  height:100%;
  object-fit:cover;
  display:block;
}
.hero-media .ghost{
  position:absolute;
  inset:0;
  background:linear-gradient(140deg,#1f1f1f 0%,#3a3a3a 52%,#1f1f1f 100%);
}
.hero-card{
  position:relative;
  z-index:var(--z3);
  min-width:0;
  margin-left:-72px;
  padding:clamp(24px,3.4vw,44px);
  background:var(--paper);
  box-shadow:var(--e4);
  text-align:center;
}
.badge{
  display:inline-block;
  margin:0 0 16px;
  padding:7px 14px;
  background:var(--ink);
  color:var(--paper);
  font-size:16px;
  letter-spacing:.14em;
  box-shadow:var(--e2);
  transform:translateY(-6px);
}
.hero-card h1{
  margin:0 0 16px;
  font-size:clamp(30px,5vw,52px);
  letter-spacing:.02em;
  overflow-wrap:break-word;
}
.lead{
  margin:0 0 24px;
  font-size:17px;
  color:var(--soft);
}
.cta{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:48px;
  padding:0 28px;
  background:var(--ink);
  color:var(--paper);
  text-decoration:none;
  font-size:17px;
  letter-spacing:.08em;
  box-shadow:var(--e2);
  transition:transform .2s ease,box-shadow .2s ease;
}
.cta:hover,.cta:focus-visible{
  transform:translateY(-3px);
  box-shadow:var(--e3);
}

/* ---------- 内容区：左栏 + 正文 ---------- */
.stage{
  display:grid;
  grid-template-columns:232px minmax(0,1fr);
  gap:clamp(16px,2.4vw,30px);
  align-items:start;
  padding-bottom:clamp(36px,6vw,64px);
}
.rail{
  position:sticky;
  top:20px;
  z-index:var(--z2);
  background:var(--paper);
  padding:16px 14px 18px;
  box-shadow:var(--e2);
  counter-reset:rail;
  min-width:0;
}
.rail-h{
  margin:0 0 10px;
  font-size:16px;
  letter-spacing:.16em;
}
.rail-h span{
  display:inline-block;
  padding-bottom:6px;
  border-bottom:3px solid var(--ink);
}
.rail-list li{counter-increment:rail}
.rail-list a{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:40px;
  padding:6px 2px;
  font-size:16px;
  text-decoration:none;
  border-bottom:1px solid var(--line);
  overflow-wrap:break-word;
}
.rail-list a::before{
  content:counter(rail,decimal-leading-zero);
  font-family:'Poiret One',sans-serif;
  color:var(--soft);
  letter-spacing:.08em;
  flex:0 0 auto;
}
.rail-list a:hover,.rail-list a:focus-visible{background:var(--ash)}

.prose{
  position:relative;
  z-index:var(--z3);
  background:var(--paper);
  padding:clamp(20px,4vw,50px);
  box-shadow:var(--e3);
  min-width:0;
  overflow-wrap:break-word;
}
.prose > article{
  padding:34px 0;
  border-top:1px solid var(--line);
}
.prose > article:first-child{
  padding-top:0;
  border-top:0;
}
.prose h2{
  margin:0 0 16px;
  font-size:clamp(22px,3vw,31px);
  letter-spacing:.03em;
}
.prose h2 span{
  display:inline-block;
  padding-bottom:8px;
  border-bottom:4px solid var(--ink);
}
.prose h3{
  margin:26px 0 12px;
  font-size:clamp(19px,2.4vw,23px);
  letter-spacing:.02em;
}
.prose h3 span{
  display:inline-block;
  padding-bottom:5px;
  border-bottom:2px solid var(--ink);
}
.prose a{border-bottom:1px solid var(--soft)}
.prose img{
  display:block;
  width:auto;
  max-width:100%;
  height:auto;
  margin:22px 0;
  box-shadow:var(--e2);
}
.prose ul,.prose ol{
  margin:0 0 18px;
  padding-left:0;
}
.prose ul li,.prose ol li{
  position:relative;
  padding:6px 0 6px 20px;
  border-bottom:1px solid var(--line);
}
.prose ul li::before{
  content:"";
  position:absolute;
  left:2px;
  top:1.05em;
  width:8px;
  height:8px;
  background:var(--ink);
}
.prose :where(table,pre,iframe,video,figure,blockquote){
  max-width:100%;
}
.prose table{
  display:block;
  width:100%;
  max-width:100%;
  overflow-x:auto;
  border-collapse:collapse;
  margin:0 0 18px;
  font-size:16px;
}
.prose th,.prose td{
  padding:9px 12px;
  text-align:left;
  vertical-align:top;
  border-bottom:1px solid var(--line);
  overflow-wrap:break-word;
}
.prose th{background:var(--ash)}
.prose pre{
  overflow-x:auto;
  margin:0 0 18px;
  padding:14px 16px;
  background:var(--ash);
  font-size:16px;
  line-height:1.6;
  box-shadow:var(--e1);
}
.prose pre code{font-size:16px}
.prose figure{margin:22px 0}
.prose blockquote{
  margin:0 0 18px;
  padding:12px 16px;
  border-left:4px solid var(--ink);
  background:var(--ash);
}

/* ---------- 页脚 ---------- */
.foot{
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1fr);
  gap:30px 34px;
  margin-top:40px;
  padding:52px max(18px,calc((100% - 1180px)/2)) 30px;
  background:var(--ink);
  color:var(--paper);
  box-shadow:var(--e4);
  position:relative;
  z-index:var(--z2);
}
.f-h{
  margin:0 0 14px;
  font-size:18px;
  letter-spacing:.14em;
}
.f-h span{
  display:inline-block;
  padding-bottom:7px;
  border-bottom:3px solid var(--paper);
}
.f-desc{
  color:rgba(255,255,255,.76);
  font-size:16px;
  max-width:36ch;
  overflow-wrap:break-word;
}
.sub{display:flex;flex-wrap:wrap;gap:10px}
.sub input{
  flex:1 1 140px;
  min-width:0;
  min-height:44px;
  padding:0 12px;
  border:0;
  background:rgba(255,255,255,.14);
  color:var(--paper);
  font-family:inherit;
  font-size:16px;
}
.sub input::placeholder{color:rgba(255,255,255,.6)}
.sub button{
  min-height:44px;
  padding:0 20px;
  border:0;
  background:var(--paper);
  color:var(--ink);
  font-family:inherit;
  font-size:16px;
  letter-spacing:.08em;
  cursor:pointer;
}
.foot-bot{
  display:flex;
  flex-wrap:wrap;
  gap:10px 18px;
  align-items:center;
  justify-content:space-between;
}
.copy{
  margin:0;
  font-size:16px;
  color:rgba(255,255,255,.7);
}
.foot-links{display:flex;flex-wrap:wrap;gap:4px 14px;min-width:0}
.foot-links a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  color:var(--paper);
  font-size:16px;
  text-decoration:none;
  border-bottom:1px solid rgba(255,255,255,.4);
}
.foot-links a:hover,.foot-links a:focus-visible{border-bottom-color:var(--paper)}

/* ---------- 底部固定条 + 全屏菜单 ---------- */
.dock{
  position:fixed;
  left:0;
  right:0;
  bottom:0;
  z-index:70;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  padding:8px 14px;
  background:rgba(255,255,255,.9);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
  box-shadow:0 -10px 28px rgba(31,31,31,.16);
}
.dock-mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:44px;
  padding:4px 10px;
  font-size:16px;
  letter-spacing:.06em;
  text-decoration:none;
  color:var(--ink);
  box-shadow:var(--e1);
  background:var(--paper);
  min-width:0;
}
.dock-mark img{
  display:block;
  height:26px;
  width:auto;
  max-width:160px;
  object-fit:contain;
}
.burger{
  position:relative;
  z-index:61;
  display:flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:8px 16px;
  background:var(--ink);
  color:var(--paper);
  font-size:16px;
  letter-spacing:.1em;
  cursor:pointer;
  list-style:none;
  box-shadow:var(--e2);
  flex:0 0 auto;
}
.burger::-webkit-details-marker{display:none}
.burger-t{line-height:1}
.bars{
  position:relative;
  display:block;
  width:18px;
  height:2px;
  background:var(--paper);
}
.bars::before,.bars::after{
  content:"";
  position:absolute;
  left:0;
  width:18px;
  height:2px;
  background:var(--paper);
}
.bars::before{top:-6px}
.bars::after{top:6px}

.sheet{
  display:none;
  position:fixed;
  inset:0;
  z-index:60;
  margin:0;
  padding:84px 0 104px;
  background:rgba(31,31,31,.97);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  overflow-y:auto;
  overflow-x:hidden;
  counter-reset:m;
}
.menu[open] .sheet{
  display:block;
  animation:sheet-up .26s ease both;
}
.sheet li{counter-increment:m}
.sheet a{
  display:flex;
  align-items:center;
  gap:16px;
  min-height:58px;
  padding:14px clamp(20px,6vw,44px);
  color:var(--paper);
  font-size:19px;
  letter-spacing:.04em;
  text-decoration:none;
  border-bottom:1px solid rgba(255,255,255,.16);
  overflow-wrap:break-word;
}
.sheet a::before{
  content:counter(m,decimal-leading-zero);
  font-family:'Poiret One',sans-serif;
  font-size:16px;
  color:rgba(255,255,255,.55);
  flex:0 0 auto;
}
.sheet a:hover,.sheet a:focus-visible{background:rgba(255,255,255,.1)}
@keyframes sheet-up{
  from{opacity:0;transform:translateY(14px)}
  to{opacity:1;transform:none}
}

/* ---------- 窄屏 ---------- */
@media (max-width:900px){
  body{padding-bottom:80px}
  .hero{
    grid-template-columns:minmax(0,1fr);
    min-height:0;
    padding:20px 0 30px;
    align-items:stretch;
  }
  .hero-media{min-height:230px;height:230px}
  .hero-card{margin:-48px 12px 0 12px;padding:26px 20px}
  .stage{grid-template-columns:minmax(0,1fr);gap:18px}
  .rail{position:static}
  .rail-list{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:0 14px}
  .foot{grid-template-columns:minmax(0,1fr);padding:36px 18px 26px;gap:24px}
  .foot-bot{justify-content:flex-start}
}
@media (max-width:520px){
  .prose{padding:20px 16px}
  .prose > article{padding:26px 0}
  .rail-list{grid-template-columns:minmax(0,1fr)}
  .dock{padding:8px 10px}
  .dock-brand{max-width:150px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .hero-media .shot{transition:none}
  .hero-media{transform:none !important}
  .menu[open] .sheet{animation:none}
  .cta{transition:none}
}

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