@import url('https://fonts.googleapis.com/css2?family=Exo+2:wght@300;400;500;600;700&family=Orbitron:wght@400;500;600;700&display=swap');

:root{
  --ink:#000000;
  --paper:#ffffff;
  --soft:#f4f4f4;
  --line:rgba(0,0,0,.16);
  --mute:rgba(0,0,0,.62);
  --shadow:0 14px 34px rgba(0,0,0,.10);
  --r:18px;
  --sans:'Exo 2','PingFang SC','Hiragino Sans GB','Microsoft YaHei',system-ui,sans-serif;
  --serif:Georgia,'Songti SC','Noto Serif SC','SimSun',serif;
  --display:'Orbitron','Exo 2','PingFang SC','Microsoft YaHei',sans-serif;
}

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

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

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}

a{color:inherit}
img,svg{display:block;max-width:100%}
p{margin:0 0 1em}
h1,h2,h3{font-family:var(--sans);font-weight:700;line-height:1.15;letter-spacing:-.02em;margin:0 0 .5em}
.subtitle{margin:0;font-family:var(--sans)}
[id]{scroll-margin-top:96px}

:focus-visible{outline:3px solid var(--ink);outline-offset:3px}
.subbar :focus-visible,.foot :focus-visible{outline-color:#000}

/* ---------- 报头 ---------- */
.masthead{border-bottom:1px solid var(--line);background:var(--paper)}
.masthead__bar{
  max-width:1240px;margin:0 auto;
  padding:16px clamp(14px,4vw,32px);
  display:grid;grid-template-columns:1fr auto 1fr;
  align-items:center;gap:12px;
}
.brand{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:44px;padding:8px 10px;white-space:nowrap;
  font-family:var(--display);font-weight:700;
  font-size:clamp(17px,2.1vw,21px);letter-spacing:.16em;
  text-decoration:none;text-align:center;
}
.masthead nav{min-width:0}
.masthead nav p{margin:0;display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.masthead__nav--l p{justify-content:flex-start}
.masthead__nav--r p{justify-content:flex-end}
.masthead nav a{
  display:inline-flex;align-items:center;min-height:44px;padding:0 16px;
  border:1px solid var(--line);border-radius:999px;
  font-size:16px;text-decoration:none;
  transition:background .2s ease,color .2s ease,border-color .2s ease;
}
.masthead nav a:hover,.masthead nav a:focus-visible{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.masthead__search{max-width:1240px;margin:0 auto;padding:0 clamp(14px,4vw,32px) 16px;display:flex;justify-content:center}
.search{width:min(100%,420px)}
.search input{
  width:100%;height:44px;padding:0 20px;
  border:1px solid var(--line);border-radius:999px;
  background:var(--soft);color:var(--ink);
  font:inherit;font-size:16px;
}
.search input::placeholder{color:var(--mute)}

/* ---------- 粘性锚点条 ---------- */
.subbar{
  position:sticky;top:0;z-index:50;
  background:var(--paper);border-bottom:1px solid var(--line);
  box-shadow:0 2px 10px rgba(0,0,0,.05);
}
.subbar__inner{
  max-width:1240px;margin:0 auto;
  padding:10px clamp(14px,4vw,32px);
  display:flex;gap:8px;overflow-x:auto;
}
.subbar__inner a{
  flex:0 0 auto;display:inline-flex;align-items:center;
  min-height:40px;padding:0 16px;
  border:1px solid var(--ink);border-radius:999px;background:var(--paper);
  font-size:16px;text-decoration:none;
  animation:rise .5s cubic-bezier(.2,.7,.2,1) backwards;
  transition:background .2s ease,color .2s ease;
}
.subbar__inner a:nth-child(2){animation-delay:.04s}
.subbar__inner a:nth-child(3){animation-delay:.08s}
.subbar__inner a:nth-child(4){animation-delay:.12s}
.subbar__inner a:nth-child(5){animation-delay:.16s}
.subbar__inner a:nth-child(6){animation-delay:.2s}
.subbar__inner a:nth-child(7){animation-delay:.24s}
.subbar__inner a:hover,.subbar__inner a:focus-visible{background:var(--ink);color:var(--paper)}

@keyframes rise{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}

/* ---------- 报眼 ---------- */
.hero{
  background-color:var(--ink);color:var(--paper);
  min-height:70vh;
  display:grid;grid-template-columns:minmax(0,150px) minmax(0,1fr);
  align-items:center;gap:clamp(16px,4vw,40px);
  padding:clamp(40px,9vw,80px) max(20px,calc((100% - 1160px) / 2));
  background-image:radial-gradient(rgba(255,255,255,.22) 1px,transparent 1px);
  background-size:22px 22px;
}
.hero__fig{margin:0;color:var(--paper);justify-self:center}
.hero__svg{width:clamp(72px,10vw,118px);height:auto;will-change:transform}
.hero__img{width:100%;height:auto;border-radius:var(--r);box-shadow:0 20px 50px rgba(255,255,255,.14)}
.hero__copy{min-width:0;text-align:center}
.hero h1{
  font-size:clamp(2rem,7vw,4.2rem);
  line-height:1.04;letter-spacing:-.03em;
  margin:0 0 .45em;
  overflow-wrap:break-word;
}
.hero__desc{
  max-width:44ch;margin:0 auto;
  color:rgba(255,255,255,.78);
  font-size:clamp(16px,2vw,18px);
}

/* ---------- 主体网格 ---------- */
.stage{
  max-width:1240px;margin:0 auto;
  padding:clamp(32px,6vw,56px) clamp(16px,4vw,32px);
  display:grid;grid-template-columns:minmax(170px,210px) minmax(0,1fr);
  gap:clamp(24px,4vw,48px);align-items:start;
}

.rail{
  position:sticky;top:76px;
  padding:18px 18px 10px;
  background:var(--paper);
  border:1px solid var(--line);border-top:4px solid var(--ink);
  border-radius:var(--r);box-shadow:var(--shadow);
}
.rail h2{font-size:18px;letter-spacing:.16em;margin:0}
.rail .subtitle{font-size:16px;color:var(--mute);margin:2px 0 12px}
.rail ul{list-style:none;margin:0;padding:0}
.rail li+li{border-top:1px solid var(--line)}
.rail a{display:flex;align-items:center;min-height:44px;font-size:16px;text-decoration:none}
.rail a:hover,.rail a:focus-visible{text-decoration:underline;text-underline-offset:4px}

/* ---------- 正文 ---------- */
.prose{
  min-width:0;max-width:70ch;
  font-family:var(--serif);font-size:17px;line-height:1.85;
  overflow-wrap:break-word;
}
.prose>section+section{
  border-top:1px solid var(--line);
  margin-top:clamp(28px,5vw,44px);
  padding-top:clamp(28px,5vw,44px);
}
.prose h2{
  font-family:var(--sans);font-size:clamp(1.5rem,3.4vw,2.1rem);
  display:flex;align-items:baseline;gap:.5em;margin:0 0 .32em;
}
.prose h3{font-family:var(--sans);font-size:1.2rem;margin:1.6em 0 .4em}
.prose p{margin:0 0 1.1em}
.prose>section:first-of-type>p:first-of-type::first-letter{
  float:left;font-size:3.4em;line-height:.82;
  padding:.04em .1em 0 0;font-weight:700;
}
.prose a{text-decoration:underline;text-underline-offset:3px}
.prose ul,.prose ol{margin:0 0 1.2em;padding-left:1.3em}
.prose li{margin:.35em 0}
.prose blockquote{
  margin:1.6em 0;padding:6px 0 6px 20px;
  border-left:4px solid var(--ink);
  font-size:1.12em;font-style:italic;
}
.prose figure{margin:1.4em 0;border-radius:var(--r);box-shadow:var(--shadow);overflow:hidden}
.prose img{height:auto;border-radius:var(--r);box-shadow:var(--shadow);margin:1.4em 0}
.prose figcaption{padding:10px 14px;font-family:var(--sans);font-size:16px;color:var(--mute)}
.prose table{
  display:block;width:100%;overflow-x:auto;
  border-collapse:collapse;font-family:var(--sans);font-size:16px;
}
.prose th,.prose td{border:1px solid var(--line);padding:10px 12px;text-align:left}

/* ---------- 页脚 ---------- */
.foot{
  margin-top:clamp(40px,8vw,72px);
  padding:clamp(36px,6vw,56px) max(20px,calc((100% - 1160px) / 2)) 24px;
  background:var(--ink);color:var(--paper);
  display:grid;grid-template-columns:1.7fr 1fr;
  gap:clamp(24px,5vw,48px);
}
.foot__word{
  font-family:var(--display);font-weight:700;
  font-size:clamp(2rem,9vw,4.4rem);line-height:.95;letter-spacing:-.02em;
  margin:0;overflow-wrap:break-word;
}
.foot h2{font-size:16px;letter-spacing:.2em;margin:0}
.foot .subtitle{font-size:16px;color:rgba(255,255,255,.62);margin:2px 0 10px}
.foot ul{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:4px 10px}
.foot a{
  display:inline-flex;align-items:center;min-height:44px;padding:0 14px;
  border:1px solid rgba(255,255,255,.32);border-radius:999px;
  font-size:16px;text-decoration:none;
  transition:background .2s ease,color .2s ease;
}
.foot a:hover,.foot a:focus-visible{background:var(--paper);color:var(--ink)}
.foot__end{
  grid-column:1 / -1;
  border-top:1px solid rgba(255,255,255,.25);
  margin-top:6px;padding-top:14px;
  font-size:16px;color:rgba(255,255,255,.66);
}
.foot__end p{margin:0}

/* ---------- 回到顶部 ---------- */
.totop{
  position:fixed;right:16px;bottom:16px;z-index:60;
  min-height:44px;padding:0 18px;
  border:1px solid var(--ink);border-radius:999px;
  background:var(--ink);color:var(--paper);
  font:inherit;font-size:16px;cursor:pointer;
  box-shadow:var(--shadow);
}
.totop[hidden]{display:none}

/* ---------- 入场 ---------- */
.js [data-reveal]{opacity:0;transform:translateY(18px);transition:opacity .7s ease,transform .7s cubic-bezier(.2,.7,.2,1)}
.js [data-reveal].is-in{opacity:1;transform:none}

/* ---------- 断点 ---------- */
@media (max-width:960px){
  .stage{grid-template-columns:minmax(0,1fr)}
  .rail{position:static;order:-1}
  .prose{max-width:none}
  .foot{grid-template-columns:minmax(0,1fr)}
}

@media (max-width:820px){
  .masthead__bar{grid-template-columns:minmax(0,1fr);gap:10px}
  .brand{order:1;font-size:19px}
  .masthead__nav--l,.masthead__nav--r{order:2}
  .masthead__nav--l p,.masthead__nav--r p{justify-content:center}
  .hero{
    grid-template-columns:minmax(0,1fr);
    min-height:auto;
    padding-top:44px;padding-bottom:44px;
  }
  .hero__svg{width:64px}
}

@media (max-width:520px){
  .subbar__inner{padding:8px 12px}
  .masthead nav a{padding:0 13px}
  .stage{padding-left:16px;padding-right:16px}
  .foot{padding-left:20px;padding-right:20px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js [data-reveal]{opacity:1;transform:none;transition:none}
  .subbar__inner a{animation:none}
  .hero__svg{will-change:auto}
}

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