@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@700&display=swap');
:root{
  --ink:#1f1f1f;
  --paper:#ffffff;
  --grey:#f5f5f5;
  --line:rgba(31,31,31,.14);
  --soft:rgba(31,31,31,.07);
  --glass:rgba(255,255,255,.74);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--grey);
  color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  font-size:17px;
  line-height:1.7;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:radial-gradient(rgba(31,31,31,.14) 1px,transparent 1px);
  background-size:18px 18px;
  opacity:.5;
}
h1,h2,h3,.brand,.cta-btn,.burger,.overlay a,.top nav a,.foot h2{
  font-family:"Space Grotesk",-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  font-weight:700;
}
a{color:inherit}
img{max-width:100%}

/* 顶部：品牌行在上、菜单行在下 */
.top{
  position:relative;
  z-index:3;
  padding:10px 16px 0;
  background:rgba(255,255,255,.78);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.top-row{
  display:grid;
  grid-template-columns:44px minmax(0,1fr) 44px;
  align-items:center;
  gap:8px;
}
.brand{
  display:flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  min-height:44px;
  text-decoration:none;
  font-size:20px;
  letter-spacing:.02em;
  text-align:center;
  word-break:break-word;
}
.brand .mark{
  display:inline-block;
  border:2px solid var(--ink);
  padding:0 6px;
  font-size:15px;
  line-height:1.5;
}
.pad{display:block}
.burger{
  width:44px;
  height:44px;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:5px;
  background:transparent;
  border:1px solid var(--line);
  border-radius:0;
  cursor:pointer;
  padding:0;
}
.burger span{
  display:block;
  width:18px;
  height:2px;
  background:var(--ink);
}
.burger:hover{background:var(--ink)}
.burger:hover span{background:var(--paper)}
.top nav.split{
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:0 10px;
  padding:4px 0 8px;
}
.top nav.split p{
  display:flex;
  flex-wrap:wrap;
  margin:0;
  gap:2px;
}
.top nav.split a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  padding:0 10px;
  font-size:16px;
  text-decoration:none;
  letter-spacing:.02em;
  border-bottom:1px solid transparent;
}
.top nav.split a:hover{
  background:var(--ink);
  color:var(--paper);
}

/* 全屏遮罩菜单 */
.overlay{
  position:fixed;
  inset:0;
  z-index:30;
  display:flex;
  flex-direction:column;
  justify-content:center;
  gap:16px;
  padding:22px 20px;
  background:var(--paper);
  opacity:0;
  visibility:hidden;
  transition:opacity .26s ease,visibility .26s ease;
  overflow-y:auto;
}
.overlay.open{opacity:1;visibility:visible}
.overlay .close{
  align-self:flex-end;
  min-height:44px;
  padding:0 20px;
  font-size:16px;
  background:transparent;
  color:var(--ink);
  border:1px solid var(--ink);
  border-radius:0;
  cursor:pointer;
  font-family:inherit;
}
.overlay .close:hover{background:var(--ink);color:var(--paper)}
.ov-title{
  margin:0;
  font-size:16px;
  letter-spacing:.2em;
  text-transform:uppercase;
  opacity:.6;
}
.overlay nav.stack p{
  margin:0;
  display:flex;
  flex-direction:column;
}
.overlay nav.stack a{
  display:block;
  min-height:50px;
  line-height:50px;
  padding:0 2px;
  font-size:24px;
  text-decoration:none;
  border-bottom:1px solid var(--line);
}
.overlay nav.stack a:hover{background:var(--grey)}

/* 主体：bento 网格 */
main{position:relative;z-index:1}
.wrap{
  display:grid;
  grid-template-columns:minmax(0,1fr) 300px;
  gap:16px;
  align-items:start;
  max-width:1180px;
  margin:0 auto;
  padding:16px 20px 52px;
}
.hero{
  grid-column:1 / -1;
  display:grid;
  grid-template-columns:1.05fr .95fr;
  min-height:70vh;
  background:var(--paper);
  border:1px solid var(--line);
  border-radius:0;
  overflow:hidden;
}
.hero-media{
  position:relative;
  background:var(--grey);
  min-height:260px;
}
.hero-media img{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
  filter:grayscale(.16) contrast(1.06);
}
.deco{
  position:absolute;
  inset:0;
  background-image:radial-gradient(var(--ink) 1.2px,transparent 1.2px);
  background-size:14px 14px;
  opacity:.45;
  animation:drift 24s linear infinite;
}
@keyframes drift{
  to{background-position:224px 224px}
}
.hero-text{
  display:flex;
  flex-direction:column;
  align-items:flex-end;
  justify-content:flex-end;
  gap:14px;
  padding:28px 24px;
  text-align:right;
}
.hero-text h1{
  margin:0;
  font-size:clamp(30px,4.6vw,54px);
  line-height:1.08;
  letter-spacing:-.02em;
  word-break:break-word;
}
.hero-text .desc{
  margin:0;
  max-width:34ch;
  font-size:16px;
  color:rgba(31,31,31,.76);
}

/* 正文卡 */
.col{
  min-width:0;
  padding:22px 20px;
  background:var(--glass);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  border:1px solid var(--line);
  border-radius:0;
}
.prose{
  max-width:68ch;
  margin:0;
  overflow-wrap:break-word;
}
.prose > :first-child{margin-top:0}
.prose h2{
  margin:1.7em 0 .5em;
  font-size:clamp(23px,3.2vw,33px);
  line-height:1.22;
  letter-spacing:-.01em;
}
.prose h2 span{box-shadow:inset 0 -.16em 0 rgba(31,31,31,.15)}
.prose h3{
  margin:1.4em 0 .45em;
  font-size:20px;
  line-height:1.35;
}
.prose h3 span{box-shadow:inset 0 -.16em 0 rgba(31,31,31,.15)}
.prose p{margin:0 0 1em}
.prose ul,.prose ol{margin:0 0 1em;padding-left:1.25em}
.prose li{margin:0 0 .35em}
.prose a{text-decoration:underline;text-underline-offset:3px}
.prose blockquote{
  margin:1.2em 0;
  padding:10px 14px;
  background:var(--grey);
  border-left:3px solid var(--ink);
}
.prose blockquote p:last-child{margin:0}
.prose table{
  width:100%;
  border-collapse:collapse;
  margin:1.2em 0;
  font-size:16px;
}
.prose th,.prose td{
  border:1px solid var(--line);
  padding:8px 10px;
  text-align:left;
  vertical-align:top;
}
.prose th{background:var(--grey)}
.prose code{
  background:var(--grey);
  padding:1px 5px;
  font-size:.95em;
}
.prose img{display:block;margin:1.2em 0}
.prose hr{border:0;border-top:1px solid var(--line);margin:2em 0}
section[id]{scroll-margin-top:18px}

/* 侧栏 */
.side{
  display:grid;
  gap:14px;
  position:sticky;
  top:16px;
}
.tile{
  padding:16px;
  background:var(--glass);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  border:1px solid var(--line);
  border-radius:0;
  transition:transform .24s ease,box-shadow .24s ease;
}
.tile:hover{
  transform:scale(1.02);
  box-shadow:0 6px 18px rgba(0,0,0,.07);
}
.tile h2{
  margin:0 0 10px;
  font-size:16px;
  letter-spacing:.14em;
}
.tile h2 span{
  display:inline-block;
  padding-bottom:3px;
  border-bottom:2px solid var(--ink);
}
.idx{
  margin:0;
  padding-left:1.4em;
  display:grid;
  gap:2px;
  font-size:16px;
}
.idx a{
  display:block;
  min-height:40px;
  line-height:40px;
  text-decoration:none;
  border-bottom:1px dashed var(--line);
}
.idx a:hover{background:var(--grey)}
.kv{
  margin:0 0 6px;
  font-size:16px;
  overflow-wrap:break-word;
}
.kv:last-child{margin-bottom:0}

/* 页脚 */
.foot{
  position:relative;
  z-index:1;
  margin-top:10px;
  padding:32px 20px 22px;
  background:var(--ink);
  color:var(--paper);
}
.foot .cta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  max-width:1180px;
  margin:0 auto 26px;
  padding-bottom:24px;
  border-bottom:1px solid rgba(255,255,255,.24);
}
.foot .cta h2{
  margin:0;
  font-size:clamp(22px,3.6vw,36px);
  line-height:1.2;
}
.cta-btn{
  display:inline-flex;
  align-items:center;
  min-height:52px;
  padding:0 26px;
  background:var(--paper);
  color:var(--ink);
  text-decoration:none;
  font-size:17px;
  transition:transform .2s ease;
}
.cta-btn:hover{transform:scale(1.04)}
.foot .cols{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:18px;
  max-width:1180px;
  margin:0 auto;
}
.foot dl{margin:0;min-width:0}
.foot dt{
  margin-bottom:6px;
  font-size:16px;
  letter-spacing:.14em;
  opacity:.72;
}
.foot dd{margin:0;font-size:16px;overflow-wrap:break-word}
.foot dd a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  text-decoration:none;
  border-bottom:1px solid rgba(255,255,255,.26);
}
.foot dd a:hover{opacity:.7}
.foot .copy{
  max-width:1180px;
  margin:26px auto 0;
  font-size:16px;
  opacity:.66;
}

/* 滚动显现 */
.rv{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .5s ease,transform .5s ease;
}
.rv.in{opacity:1;transform:none}

@media (max-width:880px){
  .wrap{
    grid-template-columns:minmax(0,1fr);
    padding:14px 14px 40px;
  }
  .hero{grid-template-columns:1fr;min-height:0}
  .hero-media{aspect-ratio:16/10;min-height:0}
  .hero-text{
    align-items:flex-start;
    text-align:left;
    padding:22px 18px;
  }
  .hero-text h1{font-size:clamp(28px,8vw,40px)}
  .side{position:static}
  .col{padding:18px 16px}
  .foot .cols{grid-template-columns:minmax(0,1fr)}
  .top nav.split a{padding:0 8px;font-size:16px}
  .overlay nav.stack a{font-size:20px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .deco{animation:none}
  .rv{opacity:1;transform:none;transition:none}
  .tile:hover,.cta-btn:hover{transform:none}
}

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