@import url('https://fonts.googleapis.com/css2?family=Anton&family=Epilogue:wght@400;500;600;700&display=swap');
:root{
  --paper:#fdfbf7;
  --paper-2:#f5f5f5;
  --ink:#1a1a1a;
  --line:#e0e0e0;
  --ash:#6a6a6a;
  --ash-in:#c9c4bb;
  --disp:'Anton','PingFang SC','Hiragino Sans GB','Microsoft YaHei',Impact,sans-serif;
  --sans:'Epilogue','PingFang SC','Hiragino Sans GB','Microsoft YaHei',system-ui,sans-serif;
  --read:'Songti SC','SimSun',Georgia,serif;
}
*{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:1.72;
  letter-spacing:.005em;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:5;
  pointer-events:none;
  opacity:.55;
  background-image:url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='0.18'/%3E%3C/svg%3E");
}
a{color:inherit}
img{max-width:100%;height:auto;display:block}
p{margin:0}

/* 顶部纸带 */
.site-head{
  position:sticky;
  top:0;
  z-index:20;
  background:var(--paper);
  border-bottom:2px solid var(--ink);
}
.nav{
  max-width:1180px;
  margin:0 auto;
  padding:10px 20px;
  display:grid;
  grid-template-columns:1fr auto 1fr auto;
  align-items:center;
  gap:8px;
}
.nav p{
  display:flex;
  flex-wrap:wrap;
  gap:4px;
  margin:0;
  min-width:0;
}
.nav-side--a{justify-content:flex-end}
.nav-side--b{justify-content:flex-start}
.nav a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 12px;
  border-radius:999px;
  border:1px solid transparent;
  text-decoration:none;
  font-size:16px;
  line-height:1.4;
  white-space:nowrap;
  transition:border-color .08s linear,background-color .08s linear,color .08s linear;
}
.nav a:hover{border-color:var(--ink)}
.nav a:focus-visible{outline:2px solid var(--ink);outline-offset:2px}
.nav a.brand{
  font-family:var(--disp);
  font-weight:700;
  font-size:1.25rem;
  letter-spacing:.02em;
  padding:0 14px;
  justify-content:center;
  white-space:nowrap;
}
.nav a.cta{
  justify-self:end;
  background:var(--ink);
  border-color:var(--ink);
  color:var(--paper);
  font-weight:700;
}
.nav a.cta:hover{background:var(--paper);color:var(--ink)}

/* 版面骨架 */
.doc{max-width:1180px;margin:0 auto;padding:0 20px}

/* 开场 */
.hero{
  display:grid;
  grid-template-columns:1.05fr .95fr;
  align-items:center;
  gap:44px;
  min-height:70vh;
  padding:52px 0 48px;
  border-bottom:1px solid var(--line);
}
.hero-copy{min-width:0;text-align:center}
h1{
  font-family:var(--disp);
  font-weight:700;
  font-size:clamp(2.1rem,5.6vw,4rem);
  line-height:1.06;
  letter-spacing:-.015em;
  margin:0 0 20px;
  text-wrap:balance;
}
.hero-desc{
  margin:0 auto;
  max-width:32ch;
  font-size:18px;
  line-height:1.75;
  color:#3a3a3a;
}
.hero-media{min-width:0}
.hero-media img{
  width:100%;
  aspect-ratio:4/3;
  object-fit:cover;
  border-radius:4px;
  border:1px solid var(--line);
  background:var(--paper-2);
}
.hero-media:empty{display:none}
.hero:has(.hero-media:empty){grid-template-columns:1fr}

/* 正文 + 侧栏 */
.body-grid{
  display:grid;
  grid-template-columns:minmax(0,1fr) 296px;
  gap:56px;
  align-items:start;
  padding:12px 0 64px;
}
.content{min-width:0}
.content article{
  scroll-margin-top:104px;
  padding:40px 0 14px;
  border-top:1px solid var(--line);
}
.content > article:first-child{border-top:0;padding-top:38px}
.content p,.content li{
  font-family:var(--read);
  font-size:17.5px;
  line-height:1.92;
}
.content p{margin:0 0 1.1em}
.content h2{
  font-family:var(--disp);
  font-size:clamp(1.45rem,3.2vw,1.95rem);
  line-height:1.2;
  letter-spacing:-.01em;
  margin:0 0 16px;
}
.content h3{
  font-family:var(--sans);
  font-weight:700;
  font-size:1.2rem;
  line-height:1.4;
  margin:28px 0 10px;
}
.content small,.eyebrow{
  display:block;
  font-family:var(--sans);
  font-size:14px;
  line-height:1.5;
  letter-spacing:.24em;
  color:var(--ash);
  margin-bottom:10px;
}
.content ul,.content ol{padding-left:1.3em;margin:0 0 1.1em}
.content li{margin:.35em 0}
.content a{text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
.content blockquote{
  margin:1.4em 0;
  padding:2px 0 2px 18px;
  border-left:3px solid var(--ink);
  color:#2a2a2a;
}
.content img{
  border-radius:4px;
  background:var(--paper-2);
  margin:1.2em 0;
}
.content hr{border:0;border-top:1px solid var(--line);margin:34px 0}
.content table{
  display:block;
  overflow-x:auto;
  width:100%;
  border-collapse:collapse;
  font-size:16px;
  line-height:1.6;
}
.content th,.content td{border:1px solid var(--line);padding:8px 10px;text-align:left}

/* 侧栏 */
.side{
  position:sticky;
  top:104px;
  min-width:0;
  padding-left:22px;
  border-left:1px solid var(--line);
}
.side-title{
  font-family:var(--disp);
  font-size:1.12rem;
  line-height:1.35;
  letter-spacing:.01em;
  margin:0 0 12px;
}
.side-list{list-style:none;margin:0;padding:0}
.side-list li + li{margin-top:2px}
.side-list a{
  display:flex;
  align-items:center;
  min-height:42px;
  padding:0 10px;
  border-radius:4px;
  text-decoration:none;
  font-size:16px;
  line-height:1.4;
  transition:background-color .08s linear;
}
.side-list a:hover{background:var(--paper-2)}

/* 页脚 */
.site-foot{
  background:var(--ink);
  color:var(--paper);
  margin-top:24px;
}
.foot-top{
  max-width:1180px;
  margin:0 auto;
  padding:44px 20px 24px;
  display:grid;
  grid-template-columns:1fr auto;
  gap:36px;
  align-items:start;
}
.foot-info{min-width:0}
address{
  display:block;
  font-style:normal;
  font-family:var(--disp);
  font-size:1.4rem;
  line-height:1.4;
  letter-spacing:.02em;
}
.foot-host{
  display:block;
  margin-top:4px;
  font-family:var(--sans);
  font-size:16px;
  letter-spacing:.06em;
  color:var(--ash-in);
}
.sub{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:20px}
.sub label{font-size:16px;line-height:1.5;color:var(--ash-in)}
.sub input{
  min-height:44px;
  width:190px;
  max-width:100%;
  padding:0 14px;
  border-radius:4px;
  border:1px solid var(--ash-in);
  background:var(--paper);
  color:var(--ink);
  font-family:inherit;
  font-size:16px;
}
.sub button{
  min-height:44px;
  padding:0 20px;
  border-radius:999px;
  border:1px solid var(--paper);
  background:var(--paper);
  color:var(--ink);
  font:inherit;
  font-weight:700;
  font-size:16px;
  cursor:pointer;
  transition:background-color .08s linear,color .08s linear;
}
.sub button:hover{background:transparent;color:var(--paper)}
.foot-links{
  list-style:none;
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:2px 22px;
  margin:0;
  padding:0;
}
.foot-links a{
  display:flex;
  align-items:center;
  min-height:40px;
  font-size:16px;
  line-height:1.4;
  text-decoration:none;
  border-bottom:1px solid transparent;
}
.foot-links a:hover{border-color:var(--paper)}
.foot-base{
  max-width:1180px;
  margin:0 auto;
  padding:16px 20px 30px;
  border-top:1px solid #3d3a35;
  text-align:center;
  font-size:16px;
  line-height:1.6;
  color:var(--ash-in);
}

/* 滚动显现 */
.reveal{
  opacity:0;
  transform:translateY(10px);
  transition:opacity .26s linear,transform .26s linear;
}
.reveal.in{opacity:1;transform:none}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
}

@media (max-width:980px){
  .body-grid{grid-template-columns:1fr;gap:30px;padding-bottom:48px}
  .side{position:static;border-left:0;border-top:1px solid var(--line);padding:24px 0 0}
  .side-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:2px 10px}
  .side-list li + li{margin-top:0}
}

@media (max-width:900px){
  .nav{
    display:flex;
    flex-wrap:wrap;
    justify-content:center;
    gap:4px;
    padding:8px 12px;
  }
  .nav a.brand{flex:1 1 100%;justify-content:center;font-size:1.2rem;padding:6px 0}
  .nav-side--a,.nav-side--b{flex:1 1 100%;justify-content:center}
  .nav-side--a a,.nav-side--b a{padding:0 10px;font-size:16px}
  .nav a.cta{flex:0 0 auto}
}

@media (max-width:820px){
  .hero{grid-template-columns:1fr;min-height:0;gap:26px;padding:34px 0 30px}
  .hero-media img{aspect-ratio:16/10}
  h1{font-size:clamp(2rem,8vw,2.7rem)}
  .hero-desc{font-size:17px}
  .content p,.content li{font-size:17px;line-height:1.85}
}

@media (max-width:620px){
  .foot-top{grid-template-columns:1fr;gap:26px;padding:36px 20px 20px}
  .foot-links{grid-template-columns:repeat(2,minmax(0,1fr))}
  .sub input{width:100%}
  .doc{padding:0 16px}
}

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