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

:root{
  --paper:#ffffff;
  --stone:#f5f5f5;
  --ink:#1f1f1f;
  --ink-8:rgba(31,31,31,.82);
  --ink-6:rgba(31,31,31,.62);
  --ink-4:rgba(31,31,31,.42);
  --line:rgba(31,31,31,.13);
  --line-soft:rgba(31,31,31,.07);
  --sh-1:0 1px 2px rgba(31,31,31,.06),0 2px 8px rgba(31,31,31,.05);
  --sh-2:0 2px 6px rgba(31,31,31,.07),0 10px 22px rgba(31,31,31,.07);
  --sh-3:0 6px 14px rgba(31,31,31,.08),0 20px 44px rgba(31,31,31,.10);
  --sh-4:0 12px 26px rgba(31,31,31,.11),0 34px 80px rgba(31,31,31,.14);
  --r:10px;
  --serif:"Libre Bodoni","Songti SC",Georgia,"Times New Roman",serif;
  --sans:"Public Sans","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --head-h:64px;
  --gutter:max(16px,4vw);
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:16.5px;
  line-height:1.72;
  overflow-x:clip;
}
h1,h2,h3,h4{font-family:var(--serif);font-weight:600;line-height:1.2}
a{color:inherit}
img{max-width:100%}
p{margin:0 0 1em}
.sr{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.wrap{width:min(1160px,100% - 32px);margin-inline:auto}

/* 顶部细条 */
.topline{background:var(--ink);color:#fff}
.topline p{
  margin:0;
  padding:7px var(--gutter);
  text-align:center;
  font-size:12px;
  letter-spacing:.26em;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

/* 书脊式页头 */
.masthead{
  position:sticky;
  top:0;
  z-index:40;
  display:flex;
  align-items:center;
  gap:14px;
  flex-wrap:wrap;
  padding:9px var(--gutter);
  background:rgba(255,255,255,.84);
  backdrop-filter:blur(14px) saturate(1.1);
  border-bottom:1px solid var(--line);
}
.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  text-decoration:none;
  color:var(--ink);
  font-family:var(--serif);
  font-size:19px;
  letter-spacing:.01em;
}
.brand .mark{
  width:40px;height:40px;
  border-radius:10px;
  object-fit:cover;
  box-shadow:var(--sh-2);
  border:1px solid var(--line);
}
.mark-type{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  background:var(--ink);
  color:#fff;
  font-size:19px;
  line-height:1;
  border:0;
}
.brand-txt{max-width:11em;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

.nav{
  margin-left:auto;
  max-width:100%;
  overflow-x:auto;
  scrollbar-width:none;
  -webkit-overflow-scrolling:touch;
}
.nav::-webkit-scrollbar{display:none}
.pills{
  display:flex;
  gap:7px;
  margin:0;
  padding:2px;
  list-style:none;
}
.pill{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 15px;
  border:1px solid var(--line);
  border-radius:999px;
  background:var(--stone);
  color:var(--ink);
  font-size:15px;
  white-space:nowrap;
  text-decoration:none;
  box-shadow:var(--sh-1);
  transition:transform .22s ease,background .22s ease,color .22s ease,box-shadow .22s ease;
}
.pill:hover,.pill:focus-visible{
  background:var(--ink);
  color:#fff;
  box-shadow:var(--sh-3);
  transform:translateY(-2px);
}

/* 主视觉：层叠浮卡 + 圆弧底边 */
.hero{
  min-height:100svh;
  display:grid;
  align-content:end;
  padding:clamp(96px,17vh,150px) 0 clamp(24px,7vh,58px);
}
.hero-card{
  position:relative;
  z-index:1;
  display:grid;
  align-items:end;
  min-height:min(70svh,600px);
  border-radius:22px 22px 118px 118px / 22px 22px 72px 72px;
  overflow:hidden;
  background:var(--ink);
  box-shadow:var(--sh-4);
  isolation:isolate;
}
.hero-fig{
  position:absolute;
  inset:-12% 0;
  margin:0;
  z-index:0;
}
.hero-fig img{
  width:100%;height:100%;
  object-fit:cover;
  display:block;
  transform:scale(1.04);
  will-change:transform;
}
.hero-fig:empty{display:none}
.hero-card::after{
  content:"";
  position:absolute;
  inset:0;
  z-index:1;
  background:linear-gradient(to top,rgba(31,31,31,.78),rgba(31,31,31,.16) 58%,rgba(31,31,31,0));
}
.hero-txt{
  position:relative;
  z-index:2;
  padding:clamp(20px,4vw,46px);
  text-align:right;
  color:#fff;
}
.hero-txt h1{
  margin:0;
  font-size:clamp(30px,5.4vw,58px);
  line-height:1.08;
  text-shadow:0 2px 18px rgba(0,0,0,.28);
  word-break:break-word;
}
.hero-sub{
  margin:.75em 0 0 auto;
  max-width:44ch;
  font-size:16px;
  line-height:1.65;
  color:rgba(255,255,255,.86);
}

/* 左栏浮卡 + 正文面板 */
.stage{
  position:relative;
  display:grid;
  grid-template-columns:218px minmax(0,1fr);
  align-items:start;
  margin:clamp(26px,5vh,58px) 0 clamp(40px,8vh,88px);
}
.rail{
  position:sticky;
  top:calc(var(--head-h) + 16px);
  z-index:3;
  margin-right:-30px;
  padding:16px 14px;
  background:#fff;
  border:1px solid var(--line);
  border-radius:var(--r);
  box-shadow:var(--sh-3);
}
.rail-h{
  margin:0 0 10px;
  padding-left:8px;
  font-size:12px;
  letter-spacing:.28em;
  color:var(--ink-4);
  font-weight:500;
}
.rail-ol{
  display:grid;
  gap:3px;
  margin:0;
  padding:0;
  list-style:none;
}
.rail-ol a{
  display:flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:0 8px;
  border-radius:8px;
  text-decoration:none;
  font-size:15px;
  line-height:1.35;
  transition:background .2s ease,box-shadow .2s ease,transform .2s ease;
}
.rail-ol .num{
  font-family:var(--serif);
  font-size:12px;
  letter-spacing:.08em;
  color:var(--ink-4);
}
.rail-ol a:hover{
  background:var(--stone);
  box-shadow:var(--sh-1);
  transform:translateX(2px);
}

.panel{
  position:relative;
  z-index:2;
  padding:clamp(20px,3vw,40px) clamp(18px,3vw,34px) clamp(28px,4vw,48px) clamp(26px,4vw,56px);
  background:#fff;
  border:1px solid var(--line);
  border-radius:var(--r);
  box-shadow:var(--sh-2);
}

/* 正文 */
.prose{font-size:16.5px}
.prose div + div{
  margin-top:clamp(34px,6vw,62px);
  padding-top:clamp(26px,5vw,46px);
  border-top:1px solid var(--line-soft);
}
.prose div[id],.prose h2,.prose h3{scroll-margin-top:calc(var(--head-h) + 20px)}
.prose h2{
  margin:0 0 .62em;
  font-size:clamp(23px,3.3vw,33px);
  letter-spacing:.005em;
}
.prose h2 > span{box-shadow:inset 0 -.3em 0 var(--stone);padding-bottom:.02em}
.prose h3{
  margin:1.5em 0 .5em;
  font-size:clamp(18px,2.2vw,22px);
  color:var(--ink-8);
}
.prose h3 > span{box-shadow:inset 0 -.34em 0 var(--stone)}
.prose p{margin:0 0 1.05em;color:var(--ink-8)}
.prose strong{color:var(--ink)}
.prose ul,.prose ol{margin:0 0 1.1em;padding-left:1.35em}
.prose li{margin:.34em 0;color:var(--ink-8)}
.prose li::marker{color:var(--ink-4)}
.prose a{
  text-decoration:none;
  box-shadow:inset 0 -1px 0 var(--ink-4);
  transition:box-shadow .2s ease;
}
.prose a:hover{box-shadow:inset 0 -2px 0 var(--ink)}
.prose blockquote{
  margin:1.3em 0;
  padding:14px 18px;
  background:var(--stone);
  border-left:3px solid var(--ink);
  border-radius:0 var(--r) var(--r) 0;
  color:var(--ink-8);
}
.prose blockquote p:last-child{margin-bottom:0}
.prose figure{margin:1.4em 0}
.prose figure img{border-radius:var(--r);box-shadow:var(--sh-2);display:block}
.prose figcaption{font-size:14px;color:var(--ink-4);margin-top:.5em}
.prose table{width:100%;border-collapse:collapse;display:block;overflow-x:auto;margin:1.2em 0;font-size:15px}
.prose th,.prose td{border:1px solid var(--line);padding:9px 12px;text-align:left}
.prose th{background:var(--stone)}
.prose hr{border:0;border-top:1px solid var(--line);margin:1.8em 0}

/* 页脚 */
.foot{
  display:grid;
  grid-template-columns:1.5fr 1fr 1.2fr;
  gap:clamp(18px,3vw,42px);
  padding:clamp(34px,6vw,62px) var(--gutter) 20px;
  background:var(--stone);
  border-top:1px solid var(--line);
}
.f-sec{min-width:0;position:relative}
.f-h{
  margin:0 0 12px;
  font-size:13px;
  letter-spacing:.2em;
  color:var(--ink-4);
  font-weight:500;
}
.f-p{font-size:15px;color:var(--ink-6);margin:0;max-width:34ch}
.f-ol{margin:0;padding:0;list-style:none;display:grid;gap:1px}
.f-ol a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  font-size:15px;
  text-decoration:none;
  color:var(--ink-8);
  transition:color .2s ease;
}
.f-ol a:hover{color:var(--ink);box-shadow:inset 0 -1px 0 var(--ink)}
.sub{display:flex;gap:8px;flex-wrap:wrap}
.sub input{
  flex:1 1 150px;
  min-width:0;
  min-height:44px;
  padding:0 12px;
  border:1px solid var(--line);
  border-radius:8px;
  background:#fff;
  color:var(--ink);
  font:inherit;
  font-size:15px;
}
.sub input:focus-visible{outline:2px solid var(--ink);outline-offset:1px}
.sub button{
  min-height:44px;
  padding:0 20px;
  border:0;
  border-radius:8px;
  background:var(--ink);
  color:#fff;
  font:inherit;
  font-size:15px;
  cursor:pointer;
  box-shadow:var(--sh-2);
  transition:transform .2s ease,box-shadow .2s ease;
}
.sub button:hover{transform:translateY(-1px);box-shadow:var(--sh-3)}
.f-base{
  grid-column:1 / -1;
  text-align:center;
  padding-top:18px;
  border-top:1px solid var(--line);
}
.f-base .copy{margin:0;font-family:var(--serif);font-size:15px;color:var(--ink-6)}
.f-base .note{margin:2px 0 .4em;font-size:13px;letter-spacing:.16em;color:var(--ink-4)}
.totop{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:40px;
  padding:0 14px;
  border-radius:999px;
  border:1px solid var(--line);
  background:#fff;
  font-size:14px;
  text-decoration:none;
  box-shadow:var(--sh-1);
}
.totop:hover{box-shadow:var(--sh-2)}

/* 动效 */
@media (prefers-reduced-motion: no-preference){
  .js .reveal{
    opacity:0;
    transform:translateY(18px);
    transition:opacity .62s ease,transform .62s cubic-bezier(.2,.7,.3,1);
  }
  .js .reveal.in{opacity:1;transform:none}
  .js .prose div:nth-child(2){transition-delay:.04s}
  .js .prose div:nth-child(3){transition-delay:.08s}
  .js .prose div:nth-child(4){transition-delay:.12s}
  .js .prose div:nth-child(5){transition-delay:.16s}
  .js .prose div:nth-child(n+6){transition-delay:.2s}
}

/* 移动端 */
@media (max-width:820px){
  :root{--head-h:104px}
  .masthead{gap:8px;padding-bottom:10px}
  .brand{font-size:17px}
  .nav{margin-left:0;flex:1 0 100%;order:3}
  .pills{padding-bottom:4px}
  .hero{padding-top:clamp(88px,14vh,120px)}
  .hero-card{min-height:min(64svh,520px);border-radius:18px 18px 74px 74px / 18px 18px 52px 52px}
  .hero-txt{padding:18px 18px 22px}
  .stage{grid-template-columns:1fr;gap:14px}
  .rail{position:static;margin:0;padding:14px}
  .rail-ol{grid-template-columns:repeat(2,minmax(0,1fr));gap:4px}
  .rail-ol a{font-size:14px;padding:0 6px}
  .panel{padding:20px 16px 26px}
  .foot{grid-template-columns:1fr 1fr}
  .f-brand{grid-column:1 / -1}
  .f-form{grid-column:1 / -1}
}

@media (max-width:430px){
  .rail-ol{grid-template-columns:1fr}
  .hero-txt h1{font-size:29px}
}

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