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

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
}

body{
  margin:0;
  background:#fff;
  color:#000;
  font-family:"Atkinson Hyperlegible","Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:17px;
  line-height:1.65;
  letter-spacing:.012em;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%;height:auto;display:block}
p{margin:0 0 1.1em}
a{color:inherit}
strong,b{font-weight:700}
hr{border:0;border-top:2px solid #000;margin:2rem 0}

:focus-visible{outline:3px solid #000;outline-offset:3px}
.foot :focus-visible{outline-color:#fff}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

::selection{background:#000;color:#fff}

/* ---------- 左侧固定竖排导航 ---------- */
.rail{
  position:fixed;
  inset:0 auto 0 0;
  width:16rem;
  z-index:20;
  display:flex;
  flex-direction:column;
  gap:1.4rem;
  padding:1.7rem 1.15rem 2rem;
  background:#fff;
  border-right:2px solid #000;
  overflow-y:auto;
  overscroll-behavior:contain;
}

.brand{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:.2rem 0;
  font-size:1.4rem;
  font-weight:700;
  letter-spacing:-.045em;
  line-height:1.1;
  text-decoration:none;
}
.brand:hover{text-decoration:underline;text-underline-offset:6px}

.rail-list{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:.5rem;
}

.rail-list a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:.5rem 1.05rem;
  border:2px solid #000;
  border-radius:999px;
  font-size:.95rem;
  line-height:1.25;
  letter-spacing:0;
  text-decoration:none;
  transition:background .18s ease,color .18s ease;
}
.rail-list a:hover,
.rail-list a:focus-visible{background:#000;color:#fff}

/* ---------- 内容列 ---------- */
.page{
  margin-left:16rem;
  min-height:100vh;
  display:flex;
  flex-direction:column;
}
main{flex:1 0 auto}

.ticker{
  position:sticky;
  top:0;
  z-index:15;
  background:#000;
  color:#fff;
  padding:.55rem 4vw;
  font-size:.78rem;
  letter-spacing:.3em;
  line-height:1.6;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}
.ticker-in{text-transform:uppercase}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;
  overflow:hidden;
  min-height:45vh;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  text-align:center;
  padding:5rem 4vw 3.5rem;
  border-bottom:2px solid #000;
}

.ghost{
  position:absolute;
  inset:0;
  margin:0;
  display:grid;
  place-items:center;
  pointer-events:none;
  overflow:hidden;
}
.ghost span{
  display:block;
  font-size:clamp(4rem,18vw,13rem);
  font-weight:700;
  line-height:1;
  letter-spacing:-.07em;
  white-space:nowrap;
  color:transparent;
  -webkit-text-stroke:2px #000;
  opacity:.15;
  will-change:transform;
}

.hero h1{
  position:relative;
  margin:0;
  max-width:20ch;
  font-size:clamp(2.6rem,7vw,6.5rem);
  font-weight:700;
  line-height:.98;
  letter-spacing:-.05em;
  text-wrap:balance;
}

.lede{
  position:relative;
  margin:1.5rem 0 0;
  max-width:34ch;
  font-size:clamp(1rem,1.5vw,1.12rem);
  line-height:1.55;
}

/* ---------- 侧栏 + 正文 ---------- */
.stage{
  display:grid;
  grid-template-columns:minmax(9rem,13rem) minmax(0,1fr);
  gap:clamp(1.6rem,4vw,3.6rem);
  padding:clamp(2.6rem,6vw,5rem) 4vw;
}

.side{
  align-self:start;
  position:sticky;
  top:4.2rem;
}

.side-title{
  margin:0 0 .8rem;
  font-size:.76rem;
  font-weight:700;
  letter-spacing:.32em;
  line-height:1.4;
}
.side-title span{display:inline-block}

.side-list{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  border-top:2px solid #000;
}
.side-list a{
  display:flex;
  align-items:center;
  min-height:42px;
  padding:.5rem 0;
  border-bottom:1px solid #000;
  font-size:.92rem;
  line-height:1.3;
  text-decoration:none;
}
.side-list a:hover{background:#000;color:#fff;padding-left:.5rem;padding-right:.5rem}

/* ---------- 正文排版 ---------- */
.prose{
  min-width:0;
  max-width:70ch;
  font-size:1.02rem;
}

.prose > article{
  padding:clamp(1.8rem,4vw,3rem) 0;
  border-top:2px solid #000;
  scroll-margin-top:5rem;
}
.prose > article:first-child{border-top:0;padding-top:0}
.prose > article:last-child{padding-bottom:0}

.prose h2{
  margin:0 0 1rem;
  font-size:clamp(1.7rem,3.6vw,2.9rem);
  font-weight:700;
  line-height:1.06;
  letter-spacing:-.04em;
}
.prose h3{
  margin:2rem 0 .6rem;
  font-size:clamp(1.22rem,2.3vw,1.65rem);
  font-weight:700;
  line-height:1.18;
  letter-spacing:-.03em;
}
.prose h2 span,.prose h3 span{display:inline-block}

.prose h4{
  margin:1.6rem 0 .4rem;
  font-size:1.05rem;
  font-weight:700;
  letter-spacing:0;
}

.prose p{margin:0 0 1.1em}
.prose > article > p:last-child{margin-bottom:0}

.prose a{
  text-decoration:underline;
  text-decoration-thickness:2px;
  text-underline-offset:3px;
}
.prose a:hover{background:#000;color:#fff;text-decoration:none}

.prose ul,.prose ol{margin:0 0 1.2em;padding-left:1.3em}
.prose li{margin:.35em 0}
.prose li::marker{font-weight:700}

.prose blockquote{
  margin:1.6rem 0;
  padding:.15rem 0 .15rem 1.1rem;
  border-left:8px solid #000;
  font-size:1.06em;
  line-height:1.55;
}
.prose blockquote p:last-child{margin-bottom:0}

.prose figure{margin:1.6rem 0}
.prose figcaption{
  margin-top:.55rem;
  font-size:.85rem;
  line-height:1.5;
  letter-spacing:.02em;
}

.prose img{
  width:100%;
  border:2px solid #000;
}

.prose table{
  width:100%;
  border-collapse:collapse;
  margin:1.4rem 0;
  font-size:.94rem;
}
.prose th,.prose td{
  border:1px solid #000;
  padding:.5rem .6rem;
  text-align:left;
  vertical-align:top;
}
.prose th{background:#000;color:#fff;font-weight:700}

.prose time{
  font-size:.88rem;
  letter-spacing:.06em;
}

.prose code,.prose pre{
  font-family:ui-monospace,Menlo,Consolas,monospace;
  font-size:.9em;
}
.prose pre{
  overflow-x:auto;
  padding:.9rem;
  border:2px solid #000;
}

.prose aside{
  margin:1.6rem 0;
  padding:1rem 1.1rem;
  border:2px solid #000;
  font-size:.95rem;
}
.prose aside > :last-child{margin-bottom:0}

/* ---------- 页脚 ---------- */
.foot{
  margin-top:auto;
  background:#000;
  color:#fff;
  padding:clamp(2.2rem,6vw,4rem) 4vw 1.6rem;
}
.foot a{color:#fff}

.foot-top{
  display:grid;
  grid-template-columns:1.5fr 1fr;
  gap:2rem;
  align-items:end;
  padding-bottom:2.2rem;
  border-bottom:1px solid rgba(255,255,255,.45);
}

.foot-title{
  margin:0 0 .7rem;
  font-size:clamp(1.8rem,4vw,2.7rem);
  font-weight:700;
  line-height:1;
  letter-spacing:-.045em;
}
.foot-title span{display:inline-block}

.foot-desc{
  margin:0;
  max-width:40ch;
  font-size:.94rem;
  line-height:1.6;
  opacity:.86;
}

.foot-form{display:flex;flex-wrap:wrap;gap:.5rem}
.foot-form input{
  flex:1 1 8rem;
  min-width:0;
  min-height:46px;
  padding:.5rem 1.1rem;
  border:2px solid #fff;
  border-radius:999px;
  background:transparent;
  color:#fff;
  font:inherit;
  font-size:.95rem;
}
.foot-form input::placeholder{color:rgba(255,255,255,.72)}
.foot-form button{
  min-height:46px;
  padding:.5rem 1.5rem;
  border:2px solid #fff;
  border-radius:999px;
  background:#fff;
  color:#000;
  font:inherit;
  font-size:.95rem;
  font-weight:700;
  cursor:pointer;
  transition:background .18s ease,color .18s ease;
}
.foot-form button:hover{background:#000;color:#fff}

.foot-cols{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:2rem;
  padding:2.2rem 0;
}
.foot-col{margin:0}
.foot-col dt{
  margin-bottom:.6rem;
  font-size:.76rem;
  letter-spacing:.3em;
}
.foot-col dd{
  margin:0;
  font-size:.94rem;
  line-height:1.5;
}
.foot-col a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:.25rem 0;
  text-decoration:none;
}
.foot-col a:hover{text-decoration:underline;text-underline-offset:4px}

.foot-copy{
  margin:0;
  padding-top:1.2rem;
  border-top:1px solid rgba(255,255,255,.45);
  font-size:.78rem;
  letter-spacing:.14em;
  opacity:.85;
}

/* ---------- 动效 ---------- */
.js-motion .reveal{
  opacity:0;
  transform:translateY(20px);
  transition:opacity .65s ease,transform .65s ease;
}
.js-motion .reveal.in{
  opacity:1;
  transform:none;
}

/* ---------- 窄屏 ---------- */
@media (max-width:900px){
  body{font-size:16.5px}

  .rail{
    position:static;
    width:auto;
    border-right:0;
    border-bottom:2px solid #000;
    gap:.55rem;
    padding:.75rem 1rem .85rem;
    overflow:visible;
  }
  .brand{font-size:1.25rem}

  .rail-list{
    flex-direction:row;
    flex-wrap:nowrap;
    gap:.45rem;
    overflow-x:auto;
    padding-bottom:.35rem;
    scrollbar-width:thin;
  }
  .rail-list li{flex:0 0 auto}
  .rail-list a{white-space:nowrap;padding:.5rem .9rem;font-size:.9rem}

  .page{margin-left:0}

  .hero{padding:3rem 1.1rem 2.6rem;min-height:40vh}
  .lede{max-width:30ch}

  .stage{
    grid-template-columns:1fr;
    padding:2rem 1.1rem 3rem;
    gap:1.6rem;
  }
  .side{position:static}
  .side-list{
    flex-direction:row;
    flex-wrap:wrap;
    gap:.4rem;
    border-top:0;
  }
  .side-list li{flex:0 0 auto}
  .side-list a{
    min-height:44px;
    padding:.45rem .9rem;
    border:2px solid #000;
    border-radius:999px;
    font-size:.88rem;
  }
  .side-list a:hover{padding-left:.9rem;padding-right:.9rem}

  .prose{max-width:none}

  .foot{padding-left:1.1rem;padding-right:1.1rem}
  .foot-top{grid-template-columns:1fr;align-items:start;gap:1.4rem}
  .foot-cols{grid-template-columns:1fr 1fr;gap:1.4rem}
}

@media (max-width:520px){
  .foot-cols{grid-template-columns:1fr}
  .prose table{font-size:.88rem}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js-motion .reveal{opacity:1;transform:none;transition:none}
  .rail-list a,.foot-form button{transition:none}
  .ghost span{will-change:auto}
}

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